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0967799
Organizational B-KEY
Self-Design I-KEY
in O
Semi-dynamic O
Environments O
ABSTRACT O
In O
this O
paper O
we O
propose O
a O
run-time O
approach O
to O
organization B-KEY
that O
is O
contingent O
on O
the O
task O
structure O
of O
the O
problem O
being O
solved O
and O
the O
environmental O
conditions O
under O
which O
it O
is O
being O
solved O
. O
We O
use O
T1EMS O
as O
the O
underlying O
representation O
for O
our O
problems O
and O
describe O
a O
framework O
that O
uses O
Organizational B-KEY
Self-Design I-KEY
-LRB- O
OSD O
-RRB- O
to O
allocate O
tasks O
and O
resources O
to O
the O
agents O
and O
coordinate B-KEY
their O
activities O
. O
The O
Sequential B-KEY
Auction I-KEY
Problem I-KEY
on O
eBay O
: O
An O
Empirical B-KEY
Analysis I-KEY
and O
a O
Solution O
* O
ABSTRACT O
Bidders O
on O
eBay O
have O
no O
dominant O
bidding B-KEY
strategy I-KEY
when O
faced O
with O
multiple B-KEY
auctions I-KEY
each O
offering O
an O
item O
of O
interest O
. O
As O
seen O
through O
an O
analysis O
of O
1,956 O
auctions O
on O
eBay O
for O
a O
Dell O
E193FP O
LCD O
monitor O
, O
some O
bidders O
win O
auctions O
at O
prices O
higher O
than O
those O
of O
other O
available O
auctions O
, O
while O
others O
never O
win O
an O
auction O
despite O
placing O
bids O
in O
losing O
efforts O
that O
are O
greater O
than O
the O
closing O
prices O
of O
other O
available O
auctions O
. O
These O
misqueues O
in O
strategic B-KEY
behavior I-KEY
hamper O
the O
efficiency O
of O
the O
system O
, O
and O
in O
so O
doing O
limit O
the O
revenue O
potential O
for O
sellers O
. O
This O
paper O
proposes O
a O
novel O
options-based O
extension O
to O
eBay O
's O
proxy-bidding O
system O
that O
resolves O
this O
strategic O
issue O
for O
buyers O
in O
commoditized B-KEY
markets I-KEY
. O
An O
empirical B-KEY
analysis I-KEY
of O
eBay O
provides O
a O
basis O
for O
computer B-KEY
simulations I-KEY
that O
investigate O
the O
market B-KEY
effects I-KEY
of O
the O
options-based O
scheme O
, O
and O
demonstrates O
that O
the O
options-based O
scheme O
provides O
greater O
efficiency O
than O
eBay O
, O
while O
also O
increasing O
seller O
revenue O
. O
Fairness B-KEY
in O
Dead-Reckoning B-KEY
based O
Distributed O
Multi-Player O
Games O
ABSTRACT O
In O
a O
distributed O
multi-player O
game O
that O
uses O
dead-reckoning B-KEY
vectors O
to O
exchange O
movement O
information O
among O
players O
, O
there O
is O
inaccuracy O
in O
rendering O
the O
objects O
at O
the O
receiver O
due O
to O
network O
delay O
between O
the O
sender O
and O
the O
receiver O
. O
The O
object O
is O
placed O
at O
the O
receiver O
at O
the O
position O
indicated O
by O
the O
dead-reckoning B-KEY
vector O
, O
but O
by O
that O
time O
, O
the O
real O
position O
could O
have O
changed O
considerably O
at O
the O
sender O
. O
This O
inaccuracy O
would O
be O
tolerable O
if O
it O
is O
consistent O
among O
all O
players O
; O
that O
is O
, O
at O
the O
same O
physical O
time O
, O
all O
players O
see O
inaccurate O
-LRB- O
with O
respect O
to O
the O
real O
position O
of O
the O
object O
-RRB- O
but O
the O
same O
position O
and O
trajectory O
for O
an O
object O
. O
But O
due O
to O
varying O
network O
delays O
between O
the O
sender O
and O
different O
receivers O
, O
the O
inaccuracy O
is O
different O
at O
different O
players O
as O
well O
. O
This O
leads O
to O
unfairness O
in O
game O
playing O
. O
In O
this O
paper O
, O
we O
first O
introduce O
an O
`` O
error O
'' O
measure O
for O
estimating O
this O
inaccuracy O
. O
Then O
we O
develop O
an O
algorithm O
for O
scheduling O
the O
sending O
of O
dead-reckoning B-KEY
vectors O
at O
a O
sender O
that O
strives O
to O
make O
this O
error O
equal O
at O
different O
receivers O
over O
time O
. O
This O
algorithm O
makes O
the O
game O
very O
fair B-KEY
at O
the O
expense O
of O
increasing O
the O
overall O
mean B-KEY
error I-KEY
of O
all O
players O
. O
To O
mitigate O
this O
effect O
, O
we O
propose O
a O
budget B-KEY
based I-KEY
algorithm I-KEY
that O
provides O
improved O
fairness B-KEY
without O
increasing O
the O
mean B-KEY
error I-KEY
thereby O
maintaining O
the O
accuracy B-KEY
of O
game O
playing O
. O
We O
have O
implemented O
both O
the O
scheduling B-KEY
algorithm I-KEY
and O
the O
budget B-KEY
based I-KEY
algorithm I-KEY
as O
part O
of O
BZFlag O
, O
a O
popular O
distributed O
multi-player O
game O
. O
We O
show O
through O
experiments O
that O
these O
algorithms O
provide O
fairness B-KEY
among O
players O
in O
spite O
of O
widely O
varying O
network O
delays O
. O
An O
additional O
property O
of O
the O
proposed O
algorithms O
is O
that O
they O
require O
less O
number O
of O
DRs O
to O
be O
exchanged O
-LRB- O
compared O
to O
the O
current O
implementation O
of O
BZflag O
-RRB- O
to O
achieve O
the O
same O
level O
of O
accuracy B-KEY
in O
game O
playing O
. O
Negotiation-Range O
Mechanisms O
: O
Exploring O
the O
Limits O
of O
Truthful O
Efficient B-KEY
Markets I-KEY
ABSTRACT O
This O
paper O
introduces O
a O
new O
class O
of O
mechanisms O
based O
on O
negotiation O
between O
market O
participants O
. O
This O
model O
allows O
us O
to O
circumvent O
Myerson O
and O
Satterthwaite O
's O
impossibility B-KEY
result I-KEY
and O
present O
a O
bilateral O
market O
mechanism O
that O
is O
efficient O
, O
individually B-KEY
rational I-KEY
, O
incentive B-KEY
compatible I-KEY
and O
budget O
balanced O
in O
the O
single-unit O
heterogeneous O
setting O
. O
The O
underlying O
scheme O
makes O
this O
combination O
of O
desirable O
qualities O
possible O
by O
reporting O
a O
price O
range O
for O
each O
buyer-seller O
pair O
that O
defines O
a O
zone B-KEY
of I-KEY
possible I-KEY
agreements I-KEY
, O
while O
the O
final O
price O
is O
left O
open O
for O
negotiation O
. O
Cost B-KEY
Sharing I-KEY
in O
a O
Job B-KEY
Scheduling I-KEY
Problem O
Using O
the O
Shapley O
Value O
ABSTRACT O
A O
set O
of O
jobs O
need O
to O
be O
served O
by O
a O
single O
server O
which O
can O
serve O
only O
one O
job O
at O
a O
time O
. O
Jobs O
have O
processing B-KEY
times I-KEY
and O
incur O
waiting O
costs O
-LRB- O
linear O
in O
their O
waiting O
time O
-RRB- O
. O
The O
jobs O
share O
their O
costs O
through O
compensation O
using O
monetary B-KEY
transfers I-KEY
. O
We O
characterize O
the O
Shapley O
value O
rule O
for O
this O
model O
using O
fairness B-KEY
axioms I-KEY
. O
Our O
axioms O
include O
a O
bound O
on O
the O
cost B-KEY
share I-KEY
of O
jobs O
in O
a O
group O
, O
efficiency O
, O
and O
some O
independence O
properties O
on O
the O
the O
cost B-KEY
share I-KEY
of O
a O
job O
. O
Combinatorial O
Resource B-KEY
Scheduling O
for O
Multiagent O
MDPs O
ABSTRACT O
Optimal O
resource B-KEY
scheduling O
in O
multiagent O
systems O
is O
a O
computationally O
challenging O
task O
, O
particularly O
when O
the O
values O
of O
resources O
are O
not O
additive O
. O
We O
consider O
the O
combinatorial O
problem O
of O
scheduling B-KEY
the O
usage O
of O
multiple O
resources B-KEY
among O
agents O
that O
operate O
in O
stochastic O
environments O
, O
modeled O
as O
Markov B-KEY
decision I-KEY
processes I-KEY
-LRB- O
MDPs O
-RRB- O
. O
In O
recent O
years O
, O
efficient O
resource-allocation O
algorithms O
have O
been O
developed O
for O
agents O
with O
resource B-KEY
values O
induced O
by O
MDPs O
. O
However O
, O
this O
prior O
work O
has O
focused O
on O
static O
resource-allocation O
problems O
where O
resources B-KEY
are O
distributed O
once O
and O
then O
utilized O
in O
infinite-horizon O
MDPs O
. O
We O
extend O
those O
existing O
models O
to O
the O
problem O
of O
combinatorial O
resource B-KEY
scheduling O
, O
where O
agents O
persist O
only O
for O
finite O
periods O
between O
their O
-LRB- O
predefined O
-RRB- O
arrival O
and O
departure O
times O
, O
requiring O
resources O
only O
for O
those O
time O
periods O
. O
We O
provide O
a O
computationally O
efficient O
procedure O
for O
computing O
globally O
optimal O
resource B-KEY
assignments O
to O
agents O
over O
time O
. O
We O
illustrate O
and O
empirically O
analyze O
the O
method O
in O
the O
context O
of O
a O
stochastic O
jobscheduling O
domain O
. O
Estimating O
the O
Global B-KEY
PageRank I-KEY
of O
Web B-KEY
Communities I-KEY
ABSTRACT O
Localized B-KEY
search I-KEY
engines I-KEY
are O
small-scale O
systems O
that O
index O
a O
particular O
community O
on O
the O
web O
. O
They O
offer O
several O
benefits O
over O
their O
large-scale O
counterparts O
in O
that O
they O
are O
relatively O
inexpensive O
to O
build O
, O
and O
can O
provide O
more O
precise O
and O
complete O
search O
capability O
over O
their O
relevant O
domains O
. O
One O
disadvantage O
such O
systems O
have O
over O
large-scale O
search O
engines O
is O
the O
lack O
of O
global B-KEY
PageRank I-KEY
values O
. O
Such O
information O
is O
needed O
to O
assess O
the O
value O
of O
pages O
in O
the O
localized O
search O
domain O
within O
the O
context O
of O
the O
web O
as O
a O
whole O
. O
In O
this O
paper O
, O
we O
present O
well-motivated O
algorithms B-KEY
to O
estimate O
the O
global B-KEY
PageRank I-KEY
values O
of O
a O
local B-KEY
domain I-KEY
. O
The O
algorithms B-KEY
are O
all O
highly O
scalable O
in O
that O
, O
given O
a O
local B-KEY
domain I-KEY
of O
size O
n O
, O
they O
use O
O O
-LRB- O
n O
-RRB- O
resources O
that O
include O
computation O
time O
, O
bandwidth O
, O
and O
storage O
. O
We O
test O
our O
methods O
across O
a O
variety O
of O
localized B-KEY
domains I-KEY
, O
including O
site-specific O
domains O
and O
topic-specific B-KEY
domains I-KEY
. O
We O
demonstrate O
that O
by O
crawling O
as O
few O
as O
n O
or O
2n O
additional O
pages O
, O
our O
methods O
can O
give O
excellent O
global B-KEY
PageRank I-KEY
estimates O
. O
On O
the O
Benefits O
of O
Cheating O
by O
Self-Interested B-KEY
Agents I-KEY
in O
Vehicular B-KEY
Networks I-KEY
∗ O
ABSTRACT O
As O
more O
and O
more O
cars O
are O
equipped O
with O
GPS O
and O
Wi-Fi O
transmitters O
, O
it O
becomes O
easier O
to O
design O
systems O
that O
will O
allow O
cars O
to O
interact O
autonomously O
with O
each O
other O
, O
e.g. O
, O
regarding O
traffic O
on O
the O
roads O
. O
Indeed O
, O
car O
manufacturers O
are O
already O
equipping O
their O
cars O
with O
such O
devices O
. O
Though O
, O
currently O
these O
systems O
are O
a O
proprietary O
, O
we O
envision O
a O
natural O
evolution O
where O
agent O
applications O
will O
be O
developed O
for O
vehicular O
systems O
, O
e.g. O
, O
to O
improve O
car O
routing O
in O
dense O
urban O
areas O
. O
Nonetheless O
, O
this O
new O
technology O
and O
agent O
applications O
may O
lead O
to O
the O
emergence O
of O
self-interested O
car O
owners O
, O
who O
will O
care O
more O
about O
their O
own O
welfare O
than O
the O
social O
welfare O
of O
their O
peers O
. O
These O
car O
owners O
will O
try O
to O
manipulate O
their O
agents O
such O
that O
they O
transmit O
false O
data O
to O
their O
peers O
. O
Using O
a O
simulation O
environment O
, O
which O
models O
a O
real O
transportation O
network O
in O
a O
large O
city O
, O
we O
demonstrate O
the O
benefits O
achieved O
by O
self-interested B-KEY
agents I-KEY
if O
no O
counter-measures O
are O
implemented O
. O
MSP O
: O
Multi-Sequence O
Positioning O
of O
Wireless O
Sensor O
Nodes O
* O
Abstract O
Wireless B-KEY
Sensor I-KEY
Networks I-KEY
have O
been O
proposed O
for O
use O
in O
many O
location-dependent O
applications O
. O
Most O
of O
these O
need O
to O
identify O
the O
locations O
of O
wireless O
sensor O
nodes O
, O
a O
challenging O
task O
because O
of O
the O
severe O
constraints O
on O
cost O
, O
energy O
and O
effective O
range O
of O
sensor O
devices O
. O
To O
overcome O
limitations O
in O
existing O
solutions O
, O
we O
present O
a O
Multi-Sequence O
Positioning O
-LRB- O
MSP O
-RRB- O
method O
for O
large-scale O
stationary O
sensor O
node B-KEY
localization I-KEY
in O
outdoor O
environments O
. O
The O
novel O
idea O
behind O
MSP O
is O
to O
reconstruct O
and O
estimate O
two-dimensional O
location O
information O
for O
each O
sensor O
node O
by O
processing O
multiple O
one-dimensional O
node O
sequences O
, O
easily O
obtained O
through O
loosely O
guided O
event B-KEY
distribution I-KEY
. O
Starting O
from O
a O
basic O
MSP O
design O
, O
we O
propose O
four O
optimizations O
, O
which O
work O
together O
to O
increase O
the O
localization B-KEY
accuracy O
. O
We O
address O
several O
interesting O
issues O
, O
such O
as O
incomplete O
-LRB- O
partial O
-RRB- O
node O
sequences O
and O
sequence O
flip O
, O
found O
in O
the O
Mirage O
test-bed O
we O
built O
. O
We O
have O
evaluated O
the O
MSP O
system O
through O
theoretical O
analysis O
, O
extensive O
simulation O
as O
well O
as O
two O
physical O
systems O
-LRB- O
an O
indoor O
version O
with O
46 O
MICAz O
motes O
and O
an O
outdoor O
version O
with O
20 O
MICAz O
motes O
-RRB- O
. O
This O
evaluation O
demonstrates O
that O
MSP O
can O
achieve O
an O
accuracy O
within O
one O
foot O
, O
requiring O
neither O
additional O
costly O
hardware O
on O
sensor O
nodes O
nor O
precise O
event B-KEY
distribution I-KEY
. O
It O
also O
provides O
a O
nice O
tradeoff O
between O
physical O
cost O
-LRB- O
anchors O
-RRB- O
and O
soft O
cost O
-LRB- O
events O
-RRB- O
, O
while O
maintaining O
localization B-KEY
accuracy O
. O
Letting O
loose O
a O
SPIDER O
on O
a O
network B-KEY
of O
POMDPs B-KEY
: O
Generating O
quality B-KEY
guaranteed I-KEY
policies I-KEY
ABSTRACT O
Distributed B-KEY
Partially I-KEY
Observable I-KEY
Markov I-KEY
Decision I-KEY
Problems I-KEY
-LRB- O
Distributed B-KEY
POMDPs I-KEY
-RRB- O
are O
a O
popular O
approach O
for O
modeling O
multi-agent O
systems O
acting O
in O
uncertain O
domains O
. O
Given O
the O
significant O
complexity O
of O
solving O
distributed B-KEY
POMDPs I-KEY
, O
particularly O
as O
we O
scale O
up O
the O
numbers O
of O
agents O
, O
one O
popular O
approach O
has O
focused O
on O
approximate O
solutions O
. O
Though O
this O
approach O
is O
efficient O
, O
the O
algorithms O
within O
this O
approach O
do O
not O
provide O
any O
guarantees O
on O
solution O
quality O
. O
A O
second O
less O
popular O
approach O
focuses O
on O
global B-KEY
optimality I-KEY
, O
but O
typical O
results O
are O
available O
only O
for O
two O
agents O
, O
and O
also O
at O
considerable O
computational O
cost O
. O
This O
paper O
overcomes O
the O
limitations O
of O
both O
these O
approaches O
by O
providing O
SPIDER O
, O
a O
novel O
combination O
of O
three O
key O
features O
for O
policy O
generation O
in O
distributed B-KEY
POMDPs I-KEY
: O
-LRB- O
i O
-RRB- O
it O
exploits O
agent O
interaction O
structure O
given O
a O
network O
of O
agents O
-LRB- O
i.e. O
allowing O
easier O
scale-up O
to O
larger O
number O
of O
agents O
-RRB- O
; O
-LRB- O
ii O
-RRB- O
it O
uses O
a O
combination O
of O
heuristics O
to O
speedup O
policy O
search O
; O
and O
-LRB- O
iii O
-RRB- O
it O
allows O
quality O
guaranteed O
approximations O
, O
allowing O
a O
systematic O
tradeoff O
of O
solution O
quality O
for O
time O
. O
Experimental O
results O
show O
orders O
of O
magnitude O
improvement O
in O
performance O
when O
compared O
with O
previous O
global B-KEY
optimal I-KEY
algorithms O
. O
A O
Point-Distribution B-KEY
Index I-KEY
and O
Its O
Application O
to O
Sensor-Grouping B-KEY
in O
Wireless B-KEY
Sensor I-KEY
Networks I-KEY
ABSTRACT O
We O
propose O
t O
, O
a O
novel O
index O
for O
evaluation O
of O
point-distribution O
. O
t O
is O
the O
minimum O
distance O
between O
each O
pair O
of O
points O
normalized O
by O
the O
average O
distance O
between O
each O
pair O
of O
points O
. O
We O
find O
that O
a O
set O
of O
points O
that O
achieve O
a O
maximum O
value O
of O
t O
result O
in O
a O
honeycomb B-KEY
structure I-KEY
. O
We O
propose O
that O
t O
can O
serve O
as O
a O
good O
index O
to O
evaluate O
the O
distribution O
of O
the O
points O
, O
which O
can O
be O
employed O
in O
coverage-related O
problems O
in O
wireless B-KEY
sensor I-KEY
networks I-KEY
-LRB- O
WSNs O
-RRB- O
. O
To O
validate O
this O
idea O
, O
we O
formulate O
a O
general O
sensorgrouping O
problem O
for O
WSNs O
and O
provide O
a O
general O
sensing O
model O
. O
We O
show O
that O
locally O
maximizing O
t O
at O
sensor O
nodes O
is O
a O
good O
approach O
to O
solve O
this O
problem O
with O
an O
algorithm O
called O
Maximizingt O
Node-Deduction O
-LRB- O
MIND O
-RRB- O
. O
Simulation O
results O
verify O
that O
MIND O
outperforms O
a O
greedy O
algorithm O
that O
exploits O
sensor-redundancy O
we O
design O
. O
This O
demonstrates O
a O
good O
application O
of O
employing O
t O
in O
coverage-related O
problems O
for O
WSNs O
. O
Robust O
Incentive B-KEY
Techniques O
for O
Peer-to-Peer O
Networks O
Lack O
of O
cooperation O
-LRB- O
free O
riding O
-RRB- O
is O
one O
of O
the O
key O
problems O
that O
confronts O
today O
's O
P2P B-KEY
systems I-KEY
. O
What O
makes O
this O
problem O
particularly O
difficult O
is O
the O
unique O
set O
of O
challenges O
that O
P2P B-KEY
systems I-KEY
pose O
: O
large O
populations O
, O
high O
turnover O
, O
asymmetry O
of O
interest O
, O
collusion B-KEY
, O
zero-cost O
identities O
, O
and O
traitors O
. O
To O
tackle O
these O
challenges O
we O
model O
the O
P2P B-KEY
system I-KEY
using O
the O
Generalized O
Prisoner O
's O
Dilemma O
-LRB- O
GPD O
-RRB- O
, O
and O
propose O
the O
Reciprocative B-KEY
decision I-KEY
function I-KEY
as O
the O
basis O
of O
a O
family O
of O
incentives B-KEY
techniques O
. O
These O
techniques O
are O
fully O
distributed O
and O
include O
: O
discriminating O
server O
selection O
, O
maxflowbased O
subjective O
reputation B-KEY
, O
and O
adaptive B-KEY
stranger I-KEY
policies I-KEY
. O
Through O
simulation O
, O
we O
show O
that O
these O
techniques O
can O
drive O
a O
system O
of O
strategic O
users O
to O
nearly O
optimal O
levels O
of O
cooperation O
. O
A O
Time B-KEY
Machine I-KEY
for O
Text B-KEY
Search I-KEY
ABSTRACT O
Text B-KEY
search I-KEY
over O
temporally O
versioned B-KEY
document I-KEY
collections I-KEY
such O
as O
web B-KEY
archives I-KEY
has O
received O
little O
attention O
as O
a O
research O
problem O
. O
As O
a O
consequence O
, O
there O
is O
no O
scalable O
and O
principled O
solution O
to O
search O
such O
a O
collection O
as O
of O
a O
specified O
time O
t O
. O
In O
this O
work O
, O
we O
address O
this O
shortcoming O
and O
propose O
an O
efficient O
solution O
for O
time-travel O
text B-KEY
search I-KEY
by O
extending O
the O
inverted O
file O
index O
to O
make O
it O
ready O
for O
temporal O
search O
. O
We O
introduce O
approximate B-KEY
temporal I-KEY
coalescing I-KEY
as O
a O
tunable O
method O
to O
reduce O
the O
index O
size O
without O
significantly O
affecting O
the O
quality O
of O
results O
. O
In O
order O
to O
further O
improve O
the O
performance O
of O
time-travel O
queries O
, O
we O
introduce O
two O
principled O
techniques O
to O
trade O
off O
index O
size O
for O
its O
performance O
. O
These O
techniques O
can O
be O
formulated O
as O
optimization O
problems O
that O
can O
be O
solved O
to O
near-optimality O
. O
Finally O
, O
our O
approach O
is O
evaluated O
in O
a O
comprehensive O
series O
of O
experiments O
on O
two O
large-scale O
real-world O
datasets O
. O
Results O
unequivocally O
show O
that O
our O
methods O
make O
it O
possible O
to O
build O
an O
efficient O
`` O
time B-KEY
machine I-KEY
'' O
scalable O
to O
large O
versioned O
text O
collections O
. O
pTHINC B-KEY
: O
A O
Thin-Client B-KEY
Architecture O
for O
Mobile B-KEY
Wireless O
Web O
ABSTRACT O
Although O
web B-KEY
applications I-KEY
are O
gaining O
popularity O
on O
mobile B-KEY
wireless O
PDAs O
, O
web O
browsers O
on O
these O
systems O
can O
be O
quite O
slow O
and O
often O
lack O
adequate O
functionality O
to O
access O
many O
web O
sites O
. O
We O
have O
developed O
pTHINC B-KEY
, O
a O
PDA B-KEY
thinclient I-KEY
solution I-KEY
that O
leverages O
more O
powerful O
servers O
to O
run O
full-function O
web B-KEY
browsers I-KEY
and O
other O
application O
logic O
, O
then O
sends O
simple O
screen O
updates O
to O
the O
PDA O
for O
display O
. O
pTHINC B-KEY
uses O
server-side O
screen O
scaling O
to O
provide O
high-fidelity O
display O
and O
seamless B-KEY
mobility I-KEY
across O
a O
broad O
range O
of O
different O
clients O
and O
screen O
sizes O
, O
including O
both O
portrait O
and O
landscape O
viewing O
modes O
. O
pTHINC B-KEY
also O
leverages O
existing O
PDA O
control O
buttons O
to O
improve O
system B-KEY
usability I-KEY
and O
maximize O
available O
screen B-KEY
resolution I-KEY
for O
application O
display O
. O
We O
have O
implemented O
pTHINC B-KEY
on O
Windows O
Mobile B-KEY
and O
evaluated O
its O
performance O
on O
mobile B-KEY
wireless O
devices O
. O
Our O
results O
compared O
to O
local B-KEY
PDA I-KEY
web I-KEY
browsers I-KEY
and O
other O
thin-client O
approaches O
demonstrate O
that O
pTHINC O
provides O
superior O
web O
browsing O
performance O
and O
is O
the O
only O
PDA O
thin O
client O
that O
effectively O
supports O
crucial O
browser O
helper O
applications O
such O
as O
video O
playback O
. O
Categories O
and O
Subject O
Descriptors O
: O
C. O
2.4 O
ComputerCommunication-Networks O
: O
Distributed O
Systems O
-- O
client O
/ O
server O
Graphical B-KEY
Models I-KEY
for O
Online O
Solutions O
to O
Interactive O
POMDPs O
ABSTRACT O
We O
develop O
a O
new O
graphical O
representation O
for O
interactive B-KEY
partially I-KEY
observable I-KEY
Markov I-KEY
decision I-KEY
processes I-KEY
-LRB- O
I-POMDPs O
-RRB- O
that O
is O
significantly O
more O
transparent O
and O
semantically O
clear O
than O
the O
previous O
representation O
. O
These O
graphical B-KEY
models I-KEY
called O
interactive B-KEY
dynamic I-KEY
influence I-KEY
diagrams I-KEY
-LRB- O
I-DIDs O
-RRB- O
seek O
to O
explicitly O
model O
the O
structure O
that O
is O
often O
present O
in O
real-world O
problems O
by O
decomposing O
the O
situation O
into O
chance O
and O
decision O
variables O
, O
and O
the O
dependencies O
between O
the O
variables O
. O
I-DIDs O
generalize O
DIDs O
, O
which O
may O
be O
viewed O
as O
graphical O
representations O
of O
POMDPs O
, O
to O
multiagent O
settings O
in O
the O
same O
way O
that O
I-POMDPs O
generalize O
POMDPs O
. O
I-DIDs O
may O
be O
used O
to O
compute O
the O
policy O
of O
an O
agent B-KEY
online I-KEY
as O
the O
agent O
acts O
and O
observes O
in O
a O
setting O
that O
is O
populated O
by O
other O
interacting O
agents O
. O
Using O
several O
examples O
, O
we O
show O
how O
I-DIDs O
may O
be O
applied O
and O
demonstrate O
their O
usefulness O
. O
An O
Outranking B-KEY
Approach I-KEY
for O
Rank B-KEY
Aggregation I-KEY
in O
Information B-KEY
Retrieval I-KEY
ABSTRACT O
Research O
in O
Information B-KEY
Retrieval I-KEY
usually O
shows O
performance O
improvement O
when O
many O
sources O
of O
evidence O
are O
combined O
to O
produce O
a O
ranking O
of O
documents O
-LRB- O
e.g. O
, O
texts O
, O
pictures O
, O
sounds O
, O
etc. O
-RRB- O
. O
In O
this O
paper O
, O
we O
focus O
on O
the O
rank B-KEY
aggregation I-KEY
problem O
, O
also O
called O
data B-KEY
fusion I-KEY
problem O
, O
where O
rankings O
of O
documents O
, O
searched O
into O
the O
same O
collection O
and O
provided O
by O
multiple O
methods O
, O
are O
combined O
in O
order O
to O
produce O
a O
new O
ranking O
. O
In O
this O
context O
, O
we O
propose O
a O
rank B-KEY
aggregation I-KEY
method O
within O
a O
multiple O
criteria O
framework O
using O
aggregation O
mechanisms O
based O
on O
decision B-KEY
rules I-KEY
identifying O
positive O
and O
negative O
reasons O
for O
judging O
whether O
a O
document O
should O
get O
a O
better O
rank O
than O
another O
. O
We O
show O
that O
the O
proposed O
method O
deals O
well O
with O
the O
Information B-KEY
Retrieval I-KEY
distinctive O
features O
. O
Experimental O
results O
are O
reported O
showing O
that O
the O
suggested O
method O
performs O
better O
than O
the O
well-known O
CombSUM O
and O
CombMNZ O
operators O
. O
Multi-dimensional B-KEY
Range I-KEY
Queries I-KEY
in O
Sensor B-KEY
Networks I-KEY
* O
ABSTRACT O
In O
many O
sensor B-KEY
networks I-KEY
, O
data O
or O
events O
are O
named O
by O
attributes O
. O
Many O
of O
these O
attributes O
have O
scalar O
values O
, O
so O
one O
natural O
way O
to O
query O
events O
of O
interest O
is O
to O
use O
a O
multidimensional B-KEY
range I-KEY
query I-KEY
. O
An O
example O
is O
: O
`` O
List O
all O
events O
whose O
temperature O
lies O
between O
50 O
◦ O
and O
60 O
◦ O
, O
and O
whose O
light O
levels O
lie O
between O
10 O
and O
15 O
. O
'' O
Such O
queries O
are O
useful O
for O
correlating O
events O
occurring O
within O
the O
network O
. O
In O
this O
paper O
, O
we O
describe O
the O
design O
of O
a O
distributed B-KEY
index I-KEY
that O
scalably O
supports O
multi-dimensional B-KEY
range I-KEY
queries I-KEY
. O
Our O
distributed B-KEY
index I-KEY
for O
multi-dimensional O
data O
-LRB- O
or O
DIM B-KEY
-RRB- O
uses O
a O
novel O
geographic O
embedding O
of O
a O
classical O
index O
data O
structure O
, O
and O
is O
built O
upon O
the O
GPSR O
geographic B-KEY
routing I-KEY
algorithm O
. O
Our O
analysis O
reveals O
that O
, O
under O
reasonable O
assumptions O
about O
query O
distributions O
, O
DIMs B-KEY
scale O
quite O
well O
with O
network O
size O
-LRB- O
both O
insertion O
and O
query B-KEY
costs I-KEY
scale O
as O
O O
-LRB- O
√ O
N O
-RRB- O
-RRB- O
. O
In O
detailed O
simulations O
, O
we O
show O
that O
in O
practice O
, O
the O
insertion O
and O
query B-KEY
costs I-KEY
of O
other O
alternatives O
are O
sometimes O
an O
order O
of O
magnitude O
more O
than O
the O
costs O
of O
DIMs B-KEY
, O
even O
for O
moderately O
sized O
network O
. O
Finally O
, O
experiments O
on O
a O
small O
scale O
testbed O
validate O
the O
feasibility O
of O
DIMs B-KEY
. O
Tracking O
Immediate B-KEY
Predecessors I-KEY
in O
Distributed B-KEY
Computations I-KEY
ABSTRACT O
A O
distributed B-KEY
computation I-KEY
is O
usually O
modeled O
as O
a O
partially O
ordered O
set O
of O
relevant B-KEY
events I-KEY
-LRB- O
the O
relevant B-KEY
events I-KEY
are O
a O
subset O
of O
the O
primitive O
events O
produced O
by O
the O
computation O
-RRB- O
. O
An O
important O
causality-related O
distributed B-KEY
computing I-KEY
problem O
, O
that O
we O
call O
the O
Immediate B-KEY
Predecessors I-KEY
Tracking O
-LRB- O
IPT O
-RRB- O
problem O
, O
consists O
in O
associating O
with O
each O
relevant O
event O
, O
on O
the O
fly O
and O
without O
using O
additional O
control O
messages O
, O
the O
set O
of O
relevant O
events O
that O
are O
its O
immediate O
predecessors O
in O
the O
partial O
order O
. O
So O
, O
IPT O
is O
the O
on-the-fly O
computation O
of O
the O
transitive B-KEY
reduction I-KEY
-LRB- O
i.e. O
, O
Hasse B-KEY
diagram I-KEY
-RRB- O
of O
the O
causality O
relation O
defined O
by O
a O
distributed B-KEY
computation I-KEY
. O
This O
paper O
addresses O
the O
IPT O
problem O
: O
it O
presents O
a O
family O
of O
protocols O
that O
provides O
each O
relevant B-KEY
event I-KEY
with O
a O
timestamp B-KEY
that O
exactly O
identifies O
its O
immediate B-KEY
predecessors I-KEY
. O
The O
family O
is O
defined O
by O
a O
general O
condition O
that O
allows O
application O
messages O
to O
piggyback B-KEY
control B-KEY
information I-KEY
whose O
size O
can O
be O
smaller O
than O
n O
-LRB- O
the O
number O
of O
processes O
-RRB- O
. O
In O
that O
sense O
, O
this O
family O
defines O
message O
size-efficient O
IPT B-KEY
protocols I-KEY
. O
According O
to O
the O
way O
the O
general O
condition O
is O
implemented O
, O
different O
IPT B-KEY
protocols I-KEY
can O
be O
obtained O
. O
Two O
of O
them O
are O
exhibited O
. O
Ranking B-KEY
Web B-KEY
Objects I-KEY
from O
Multiple O
Communities O
ABSTRACT O
Vertical B-KEY
search I-KEY
is O
a O
promising O
direction O
as O
it O
leverages O
domainspecific O
knowledge O
and O
can O
provide O
more O
precise O
information O
for O
users O
. O
In O
this O
paper O
, O
we O
study O
the O
Web O
object-ranking O
problem O
, O
one O
of O
the O
key O
issues O
in O
building O
a O
vertical O
search O
engine O
. O
More O
specifically O
, O
we O
focus O
on O
this O
problem O
in O
cases O
when O
objects O
lack O
relationships O
between O
different O
Web O
communities O
, O
and O
take O
high-quality O
photo O
search O
as O
the O
test O
bed O
for O
this O
investigation O
. O
We O
proposed O
two O
score B-KEY
fusion I-KEY
methods I-KEY
that O
can O
automatically O
integrate O
as O
many O
Web O
communities O
-LRB- O
Web O
forums O
-RRB- O
with O
rating O
information O
as O
possible O
. O
The O
proposed O
fusion O
methods O
leverage O
the O
hidden O
links O
discovered O
by O
a O
duplicate B-KEY
photo I-KEY
detection I-KEY
algorithm I-KEY
, O
and O
aims O
at O
minimizing O
score O
differences O
of O
duplicate O
photos O
in O
different O
forums O
. O
Both O
intermediate O
results O
and O
user O
studies O
show O
the O
proposed O
fusion O
methods O
are O
practical O
and O
efficient O
solutions O
to O
Web B-KEY
object I-KEY
ranking B-KEY
in O
cases O
we O
have O
described O
. O
Though O
the O
experiments O
were O
conducted O
on O
high-quality O
photo O
ranking B-KEY
, O
the O
proposed O
algorithms B-KEY
are O
also O
applicable O
to O
other O
ranking B-KEY
problems O
, O
such O
as O
movie O
ranking B-KEY
and O
music O
ranking B-KEY
. O
A O
Dynamic O
Pari-Mutuel B-KEY
Market I-KEY
for O
Hedging O
, O
Wagering O
, O
and O
Information O
Aggregation O
ABSTRACT O
I O
develop O
a O
new O
mechanism O
for O
risk B-KEY
allocation I-KEY
and O
information B-KEY
speculation I-KEY
called O
a O
dynamic O
pari-mutuel O
market O
-LRB- O
DPM O
-RRB- O
. O
A O
DPM B-KEY
acts O
as O
hybrid B-KEY
between O
a O
pari-mutuel B-KEY
market I-KEY
and O
a O
continuous B-KEY
double I-KEY
auction I-KEY
-LRB- O
CDA B-KEY
-RRB- O
, O
inheriting O
some O
of O
the O
advantages O
of O
both O
. O
Like O
a O
pari-mutuel B-KEY
market I-KEY
, O
a O
DPM B-KEY
offers O
infinite O
buy-in O
liquidity O
and O
zero B-KEY
risk I-KEY
for O
the O
market B-KEY
institution I-KEY
; O
like O
a O
CDA B-KEY
, O
a O
DPM B-KEY
can O
continuously O
react O
to O
new O
information O
, O
dynamically O
incorporate O
information O
into O
prices B-KEY
, O
and O
allow O
traders O
to O
lock O
in O
gains B-KEY
or O
limit O
losses B-KEY
by O
selling B-KEY
prior O
to O
event B-KEY
resolution I-KEY
. O
The O
trader B-KEY
interface I-KEY
can O
be O
designed O
to O
mimic O
the O
familiar O
double B-KEY
auction I-KEY
format I-KEY
with O
bid-ask B-KEY
queues I-KEY
, O
though O
with O
an O
addition O
variable O
called O
the O
payoff B-KEY
per I-KEY
share I-KEY
. O
The O
DPM B-KEY
price B-KEY
function O
can O
be O
viewed O
as O
an O
automated O
market O
maker O
always O
offering O
to O
sell O
at O
some O
price O
, O
and O
moving O
the O
price O
appropriately O
according O
to O
demand O
. O
Since O
the O
mechanism O
is O
pari-mutuel O
-LRB- O
i.e. O
, O
redistributive O
-RRB- O
, O
it O
is O
guaranteed O
to O
pay O
out O
exactly O
the O
amount O
of O
money O
taken O
in O
. O
I O
explore O
a O
number O
of O
variations O
on O
the O
basic O
DPM B-KEY
, O
analyzing O
the O
properties O
of O
each O
, O
and O
solving O
in O
closed O
form O
for O
their O
respective O
price B-KEY
functions O
. O
Playing O
Games O
in O
Many O
Possible O
Worlds O
ABSTRACT O
In O
traditional O
game B-KEY
theory I-KEY
, O
players O
are O
typically O
endowed O
with O
exogenously O
given O
knowledge O
of O
the O
structure O
of O
the O
game O
-- O
either O
full O
omniscient O
knowledge O
or O
partial O
but O
fixed O
information O
. O
In O
real O
life O
, O
however O
, O
people O
are O
often O
unaware O
of O
the O
utility O
of O
taking O
a O
particular O
action O
until O
they O
perform O
research O
into O
its O
consequences O
. O
In O
this O
paper O
, O
we O
model O
this O
phenomenon O
. O
We O
imagine O
a O
player O
engaged O
in O
a O
questionand-answer O
session O
, O
asking O
questions O
both O
about O
his O
or O
her O
own O
preferences O
and O
about O
the O
state O
of O
reality O
; O
thus O
we O
call O
this O
setting O
`` O
Socratic O
'' O
game B-KEY
theory I-KEY
. O
In O
a O
Socratic B-KEY
game I-KEY
, O
players O
begin O
with O
an O
a O
priori B-KEY
probability I-KEY
distribution I-KEY
over O
many O
possible O
worlds O
, O
with O
a O
different O
utility O
function O
for O
each O
world O
. O
Players O
can O
make O
queries O
, O
at O
some O
cost O
, O
to O
learn O
partial O
information O
about O
which O
of O
the O
possible O
worlds O
is O
the O
actual O
world O
, O
before O
choosing O
an O
action O
. O
We O
consider O
two O
query O
models O
: O
-LRB- O
1 O
-RRB- O
an O
unobservable-query O
model O
, O
in O
which O
players O
learn O
only O
the O
response O
to O
their O
own O
queries O
, O
and O
-LRB- O
2 O
-RRB- O
an O
observable-query O
model O
, O
in O
which O
players O
also O
learn O
which O
queries O
their O
opponents O
made O
. O
The O
results O
in O
this O
paper O
consider O
cases O
in O
which O
the O
underlying O
worlds O
of O
a O
two-player O
Socratic B-KEY
game I-KEY
are O
either O
constant-sum B-KEY
games I-KEY
or O
strategically O
zero-sum O
games O
, O
a O
class O
that O
generalizes O
constant-sum B-KEY
games I-KEY
to O
include O
all O
games O
in O
which O
the O
sum O
of O
payoffs O
depends O
linearly O
on O
the O
interaction O
between O
the O
players O
. O
When O
the O
underlying O
worlds O
are O
constant O
sum O
, O
we O
give O
polynomial-time O
algorithms B-KEY
to O
find O
Nash O
equilibria O
in O
both O
the O
observable O
- O
and O
unobservable-query O
models O
. O
When O
the O
worlds O
are O
strategically O
zero O
sum O
, O
we O
give O
efficient O
algorithms B-KEY
to O
find O
Nash O
equilibria O
in O
unobservablequery O
Socratic B-KEY
games I-KEY
and O
correlated O
equilibria O
in O
observablequery O
Socratic B-KEY
games I-KEY
. O
A O
Study O
of O
Factors O
Affecting O
the O
Utility O
of O
Implicit B-KEY
Relevance I-KEY
Feedback I-KEY
ABSTRACT O
Implicit B-KEY
relevance I-KEY
feedback I-KEY
-LRB- O
IRF O
-RRB- O
is O
the O
process O
by O
which O
a O
search O
system O
unobtrusively O
gathers O
evidence O
on O
searcher O
interests O
from O
their O
interaction O
with O
the O
system O
. O
IRF O
is O
a O
new O
method O
of O
gathering O
information O
on O
user O
interest O
and O
, O
if O
IRF O
is O
to O
be O
used O
in O
operational O
IR O
systems O
, O
it O
is O
important O
to O
establish O
when O
it O
performs O
well O
and O
when O
it O
performs O
poorly O
. O
In O
this O
paper O
we O
investigate O
how O
the O
use O
and O
effectiveness O
of O
IRF O
is O
affected O
by O
three O
factors O
: O
search B-KEY
task I-KEY
complexity I-KEY
, O
the O
search O
experience O
of O
the O
user O
and O
the O
stage O
in O
the O
search O
. O
Our O
findings O
suggest O
that O
all O
three O
of O
these O
factors O
contribute O
to O
the O
utility O
of O
IRF O
. O
Multi-Attribute O
Coalitional B-KEY
Games I-KEY
* O
t O
ABSTRACT O
We O
study O
coalitional B-KEY
games I-KEY
where O
the O
value O
of O
cooperation B-KEY
among O
the O
agents B-KEY
are O
solely O
determined O
by O
the O
attributes O
the O
agents B-KEY
possess O
, O
with O
no O
assumption O
as O
to O
how O
these O
attributes O
jointly O
determine O
this O
value O
. O
This O
framework O
allows O
us O
to O
model O
diverse B-KEY
economic I-KEY
interactions I-KEY
by O
picking O
the O
right O
attributes O
. O
We O
study O
the O
computational B-KEY
complexity I-KEY
of O
two O
coalitional O
solution O
concepts O
for O
these O
games O
-- O
the O
Shapley O
value O
and O
the O
core B-KEY
. O
We O
show O
how O
the O
positive O
results O
obtained O
in O
this O
paper O
imply O
comparable O
results O
for O
other O
games O
studied O
in O
the O
literature O
. O
Weak B-KEY
Monotonicity I-KEY
Suffices O
for O
Truthfulness B-KEY
on O
Convex B-KEY
Domains I-KEY
ABSTRACT O
Weak B-KEY
monotonicity I-KEY
is O
a O
simple O
necessary O
condition O
for O
a O
social B-KEY
choice I-KEY
function I-KEY
to O
be O
implementable O
by O
a O
truthful B-KEY
mechanism O
. O
Roberts O
-LSB- O
10 O
-RSB- O
showed O
that O
it O
is O
sufficient O
for O
all O
social B-KEY
choice I-KEY
functions I-KEY
whose O
domain O
is O
unrestricted O
. O
Lavi O
, O
Mu'alem O
and O
Nisan O
-LSB- O
6 O
-RSB- O
proved O
the O
sufficiency O
of O
weak B-KEY
monotonicity I-KEY
for O
functions O
over O
order-based O
domains O
and O
Gui O
, O
Muller O
and O
Vohra O
-LSB- O
5 O
-RSB- O
proved O
sufficiency O
for O
order-based O
domains O
with O
range O
constraints O
and O
for O
domains O
defined O
by O
other O
special O
types O
of O
linear O
inequality O
constraints O
. O
Here O
we O
show O
the O
more O
general O
result O
, O
conjectured O
by O
Lavi O
, O
Mu'alem O
and O
Nisan O
-LSB- O
6 O
-RSB- O
, O
that O
weak B-KEY
monotonicity I-KEY
is O
sufficient O
for O
functions O
defined O
on O
any O
convex B-KEY
domain I-KEY
. O
Using O
Asymmetric O
Distributions O
to O
Improve O
Text B-KEY
Classifier I-KEY
Probability B-KEY
Estimates I-KEY
ABSTRACT O
Text B-KEY
classifiers I-KEY
that O
give O
probability B-KEY
estimates I-KEY
are O
more O
readily O
applicable O
in O
a O
variety O
of O
scenarios O
. O
For O
example O
, O
rather O
than O
choosing O
one O
set O
decision B-KEY
threshold I-KEY
, O
they O
can O
be O
used O
in O
a O
Bayesian B-KEY
risk I-KEY
model I-KEY
to O
issue O
a O
run-time O
decision O
which O
minimizes O
a O
userspecified O
cost O
function O
dynamically O
chosen O
at O
prediction O
time O
. O
However O
, O
the O
quality O
of O
the O
probability B-KEY
estimates I-KEY
is O
crucial O
. O
We O
review O
a O
variety O
of O
standard O
approaches O
to O
converting O
scores O
-LRB- O
and O
poor O
probability B-KEY
estimates I-KEY
-RRB- O
from O
text B-KEY
classifiers I-KEY
to O
high O
quality O
estimates O
and O
introduce O
new O
models O
motivated O
by O
the O
intuition O
that O
the O
empirical B-KEY
score I-KEY
distribution I-KEY
for O
the O
`` O
extremely O
irrelevant O
'' O
, O
`` O
hard O
to O
discriminate O
'' O
, O
and O
`` O
obviously O
relevant O
'' O
items O
are O
often O
significantly O
different O
. O
Finally O
, O
we O
analyze O
the O
experimental O
performance O
of O
these O
models O
over O
the O
outputs O
of O
two O
text B-KEY
classifiers I-KEY
. O
The O
analysis O
demonstrates O
that O
one O
of O
these O
models O
is O
theoretically O
attractive O
-LRB- O
introducing O
few O
new O
parameters O
while O
increasing O
flexibility O
-RRB- O
, O
computationally O
efficient O
, O
and O
empirically O
preferable O
. O
Adaptive O
Duty B-KEY
Cycling I-KEY
for O
Energy B-KEY
Harvesting I-KEY
Systems O
-LCB- O
jasonh O
, O
kansal O
, O
szahedi O
, O
mbs O
-RCB- O
@ O
ee.ucla.edu O
vijay@nec-labs.com O
ABSTRACT O
Harvesting O
energy O
from O
the O
environment O
is O
feasible O
in O
many O
applications O
to O
ameliorate O
the O
energy O
limitations O
in O
sensor B-KEY
networks I-KEY
. O
In O
this O
paper O
, O
we O
present O
an O
adaptive O
duty B-KEY
cycling I-KEY
algorithm O
that O
allows O
energy B-KEY
harvesting I-KEY
sensor O
nodes O
to O
autonomously O
adjust O
their O
duty B-KEY
cycle I-KEY
according O
to O
the O
energy O
availability O
in O
the O
environment O
. O
The O
algorithm O
has O
three O
objectives O
, O
namely O
-LRB- O
a O
-RRB- O
achieving O
energy B-KEY
neutral I-KEY
operation I-KEY
, O
i.e. O
, O
energy O
consumption O
should O
not O
be O
more O
than O
the O
energy O
provided O
by O
the O
environment O
, O
-LRB- O
b O
-RRB- O
maximizing O
the O
system O
performance O
based O
on O
an O
application O
utility O
model O
subject O
to O
the O
above O
energyneutrality O
constraint O
, O
and O
-LRB- O
c O
-RRB- O
adapting O
to O
the O
dynamics O
of O
the O
energy O
source O
at O
run-time O
. O
We O
present O
a O
model O
that O
enables O
harvesting O
sensor O
nodes O
to O
predict O
future O
energy O
opportunities O
based O
on O
historical O
data O
. O
We O
also O
derive O
an O
upper O
bound O
on O
the O
maximum O
achievable O
performance O
assuming O
perfect O
knowledge O
about O
the O
future O
behavior O
of O
the O
energy O
source O
. O
Our O
methods O
are O
evaluated O
using O
data O
gathered O
from O
a O
prototype O
solar O
energy B-KEY
harvesting I-KEY
platform O
and O
we O
show O
that O
our O
algorithm O
can O
utilize O
up O
to O
58 O
% O
more O
environmental B-KEY
energy I-KEY
compared O
to O
the O
case O
when O
harvesting-aware O
power B-KEY
management I-KEY
is O
not O
used O
. O
A O
Complete O
Distributed B-KEY
Constraint I-KEY
Optimization I-KEY
Method O
For O
Non-Traditional O
Pseudotree B-KEY
Arrangements I-KEY
* O
ABSTRACT O
Distributed B-KEY
Constraint I-KEY
Optimization I-KEY
-LRB- O
DCOP O
-RRB- O
is O
a O
general O
framework O
that O
can O
model O
complex O
problems O
in O
multi-agent O
systems O
. O
Several O
current O
algorithms O
that O
solve O
general O
DCOP O
instances O
, O
including O
ADOPT O
and O
DPOP O
, O
arrange O
agents B-KEY
into O
a O
traditional O
pseudotree O
structure O
. O
We O
introduce O
an O
extension O
to O
the O
DPOP O
algorithm O
that O
handles O
an O
extended O
set O
of O
pseudotree B-KEY
arrangements I-KEY
. O
Our O
algorithm O
correctly O
solves O
DCOP O
instances O
for O
pseudotrees O
that O
include O
edges O
between O
nodes O
in O
separate O
branches O
. O
The O
algorithm O
also O
solves O
instances O
with O
traditional O
pseudotree B-KEY
arrangements I-KEY
using O
the O
same O
procedure O
as O
DPOP O
. O
We O
compare O
our O
algorithm O
with O
DPOP O
using O
several O
metrics O
including O
the O
induced O
width O
of O
the O
pseudotrees O
, O
the O
maximum O
dimensionality O
of O
messages O
and O
computation O
, O
and O
the O
maximum B-KEY
sequential I-KEY
path I-KEY
cost I-KEY
through O
the O
algorithm O
. O
We O
prove O
that O
for O
some O
problem O
instances O
it O
is O
not O
possible O
to O
generate O
a O
traditional O
pseudotree O
using O
edge-traversal O
heuristics O
that O
will O
outperform O
a O
cross-edged B-KEY
pseudotree I-KEY
. O
We O
use O
multiple O
heuristics O
to O
generate O
pseudotrees O
and O
choose O
the O
best O
pseudotree O
in O
linear O
space-time O
complexity O
. O
For O
some O
problem O
instances O
we O
observe O
significant O
improvements O
in O
message O
and O
computation O
sizes O
compared O
to O
DPOP O
. O
Hypotheses O
Refinement O
under O
Topological O
Communication O
Constraints O
* O
ABSTRACT O
We O
investigate O
the O
properties O
of O
a O
multiagent B-KEY
system I-KEY
where O
each O
-LRB- O
distributed O
-RRB- O
agent O
locally O
perceives O
its O
environment O
. O
Upon O
perception O
of O
an O
unexpected O
event O
, O
each O
agent O
locally O
computes O
its O
favoured B-KEY
hypothesis I-KEY
and O
tries O
to O
propagate O
it O
to O
other O
agents O
, O
by O
exchanging O
hypotheses O
and O
supporting O
arguments O
-LRB- O
observations O
-RRB- O
. O
However O
, O
we O
further O
assume O
that O
communication O
opportunities O
are O
severely O
constrained O
and O
change O
dynamically O
. O
In O
this O
paper O
, O
we O
mostly O
investigate O
the O
convergence O
of O
such O
systems O
towards O
global B-KEY
consistency I-KEY
. O
We O
first O
show O
that O
-LRB- O
for O
a O
wide O
class O
of O
protocols O
that O
we O
shall O
define O
-RRB- O
, O
the O
communication O
constraints O
induced O
by O
the O
topology O
will O
not O
prevent O
the O
convergence O
of O
the O
system O
, O
at O
the O
condition O
that O
the O
system O
dynamics O
guarantees O
that O
no O
agent O
will O
ever O
be O
isolated O
forever O
, O
and O
that O
agents O
have O
unlimited O
time O
for O
computation O
and O
arguments O
exchange O
. O
As O
this O
assumption O
can O
not O
be O
made O
in O
most O
situations O
though O
, O
we O
then O
set O
up O
an O
experimental O
framework O
aiming O
at O
comparing O
the O
relative O
efficiency O
and O
effectiveness O
of O
different O
interaction O
protocols O
for O
hypotheses O
exchange O
. O
We O
study O
a O
critical O
situation O
involving O
a O
number O
of O
agents O
aiming O
at O
escaping O
from O
a O
burning O
building O
. O
The O
results O
reported O
here O
provide O
some O
insights O
regarding O
the O
design O
of O
optimal O
protocol O
for O
hypotheses O
refinement O
in O
this O
context O
. O
Cross-Lingual O
Query B-KEY
Suggestion I-KEY
Using O
Query B-KEY
Logs I-KEY
of O
Different O
Languages O
ABSTRACT O
Query B-KEY
suggestion I-KEY
aims O
to O
suggest O
relevant O
queries O
for O
a O
given O
query O
, O
which O
help O
users O
better O
specify O
their O
information O
needs O
. O
Previously O
, O
the O
suggested O
terms O
are O
mostly O
in O
the O
same O
language O
of O
the O
input O
query O
. O
In O
this O
paper O
, O
we O
extend O
it O
to O
cross-lingual O
query B-KEY
suggestion I-KEY
-LRB- O
CLQS O
-RRB- O
: O
for O
a O
query O
in O
one O
language O
, O
we O
suggest O
similar O
or O
relevant O
queries O
in O
other O
languages O
. O
This O
is O
very O
important O
to O
scenarios O
of O
cross-language B-KEY
information I-KEY
retrieval I-KEY
-LRB- O
CLIR O
-RRB- O
and O
cross-lingual O
keyword B-KEY
bidding I-KEY
for O
search B-KEY
engine I-KEY
advertisement O
. O
Instead O
of O
relying O
on O
existing O
query B-KEY
translation I-KEY
technologies O
for O
CLQS O
, O
we O
present O
an O
effective O
means O
to O
map B-KEY
the O
input O
query O
of O
one O
language O
to O
queries O
of O
the O
other O
language O
in O
the O
query B-KEY
log I-KEY
. O
Important O
monolingual O
and O
cross-lingual O
information O
such O
as O
word O
translation O
relations O
and O
word O
co-occurrence O
statistics O
, O
etc. O
are O
used O
to O
estimate O
the O
cross-lingual O
query O
similarity O
with O
a O
discriminative O
model O
. O
Benchmarks B-KEY
show O
that O
the O
resulting O
CLQS O
system O
significantly O
outperforms O
a O
baseline O
system O
based O
on O
dictionary-based O
query B-KEY
translation I-KEY
. O
Besides O
, O
the O
resulting O
CLQS O
is O
tested O
with O
French O
to O
English O
CLIR O
tasks O
on O
TREC O
collections O
. O
The O
results O
demonstrate O
higher O
effectiveness O
than O
the O
traditional O
query B-KEY
translation I-KEY
methods O
. O
Networks B-KEY
Preserving O
Evolutionary O
Equilibria O
and O
the O
Power B-KEY
of I-KEY
Randomization I-KEY
We O
study O
a O
natural O
extension O
of O
classical O
evolutionary B-KEY
game I-KEY
theory I-KEY
to O
a O
setting O
in O
which O
pairwise O
interactions O
are O
restricted O
to O
the O
edges O
of O
an O
undirected O
graph O
or O
network O
. O
We O
generalize O
the O
definition O
of O
an O
evolutionary B-KEY
stable I-KEY
strategy I-KEY
-LRB- O
ESS O
-RRB- O
, O
and O
show O
a O
pair O
of O
complementary O
results O
that O
exhibit O
the O
power B-KEY
of I-KEY
randomization I-KEY
in O
our O
setting O
: O
subject O
to O
degree O
or O
edge B-KEY
density I-KEY
conditions I-KEY
, O
the O
classical O
ESS O
of O
any O
game O
are O
preserved O
when O
the O
graph O
is O
chosen O
randomly O
and O
the O
mutation B-KEY
set I-KEY
is O
chosen O
adversarially O
, O
or O
when O
the O
graph O
is O
chosen O
adversarially O
and O
the O
mutation B-KEY
set I-KEY
is O
chosen O
randomly O
. O
We O
examine O
natural B-KEY
strengthenings I-KEY
of O
our O
generalized O
ESS O
definition O
, O
and O
show O
that O
similarly O
strong O
results O
are O
not O
possible O
for O
them O
. O
Bid B-KEY
Expressiveness O
and O
Clearing O
Algorithms O
in O
Multiattribute O
Double O
Auctions B-KEY
ABSTRACT O
We O
investigate O
the O
space O
of O
two-sided O
multiattribute B-KEY
auctions I-KEY
, O
focusing O
on O
the O
relationship O
between O
constraints O
on O
the O
offers O
traders O
can O
express O
through O
bids O
, O
and O
the O
resulting O
computational O
problem O
of O
determining O
an O
optimal O
set O
of O
trades O
. O
We O
develop O
a O
formal O
semantic B-KEY
framework I-KEY
for O
characterizing O
expressible O
offers O
, O
and O
show O
conditions O
under O
which O
the O
allocation O
problem O
can O
be O
separated O
into O
first O
identifying O
optimal O
pairwise O
trades O
and O
subsequently O
optimizing O
combinations O
of O
those O
trades O
. O
We O
analyze O
the O
bilateral O
matching O
problem O
while O
taking O
into O
consideration O
relevant O
results O
from O
multiattribute B-KEY
utility I-KEY
theory I-KEY
. O
Network O
flow O
models O
we O
develop O
for O
computing O
global B-KEY
allocations I-KEY
facilitate O
classification O
of O
the O
problem O
space O
by O
computational O
complexity O
, O
and O
provide O
guidance O
for O
developing O
solution O
algorithms O
. O
Experimental O
trials O
help O
distinguish O
tractable O
problem O
classes O
for O
proposed O
solution O
techniques O
. O
Privacy B-KEY
in O
Electronic B-KEY
Commerce I-KEY
and O
the O
Economics O
of O
Immediate B-KEY
Gratification I-KEY
ABSTRACT O
Dichotomies O
between O
privacy B-KEY
attitudes O
and O
behavior O
have O
been O
noted O
in O
the O
literature O
but O
not O
yet O
fully O
explained O
. O
We O
apply O
lessons O
from O
the O
research O
on O
behavioral O
economics O
to O
understand O
the O
individual B-KEY
decision I-KEY
making I-KEY
process I-KEY
with O
respect O
to O
privacy B-KEY
in O
electronic B-KEY
commerce I-KEY
. O
We O
show O
that O
it O
is O
unrealistic O
to O
expect O
individual O
rationality B-KEY
in O
this O
context O
. O
Models O
of O
self-control B-KEY
problems I-KEY
and O
immediate B-KEY
gratification I-KEY
offer O
more O
realistic O
descriptions O
of O
the O
decision O
process O
and O
are O
more O
consistent O
with O
currently O
available O
data O
. O
In O
particular O
, O
we O
show O
why O
individuals O
who O
may O
genuinely O
want O
to O
protect O
their O
privacy B-KEY
might O
not O
do O
so O
because O
of O
psychological B-KEY
distortions I-KEY
well O
documented O
in O
the O
behavioral O
literature O
; O
we O
show O
that O
these O
distortions O
may O
affect O
not O
only O
` O
na O
¨ O
ıve O
' O
individuals O
but O
also O
` O
sophisticated O
' O
ones O
; O
and O
we O
prove O
that O
this O
may O
occur O
also O
when O
individuals O
perceive O
the O
risks O
from O
not O
protecting O
their O
privacy B-KEY
as O
significant O
. O
Bidding B-KEY
Algorithms I-KEY
for O
a O
Distributed O
Combinatorial B-KEY
Auction I-KEY
ABSTRACT O
Distributed B-KEY
allocation I-KEY
and O
multiagent O
coordination B-KEY
problems O
can O
be O
solved O
through O
combinatorial B-KEY
auctions I-KEY
. O
However O
, O
most O
of O
the O
existing O
winner O
determination O
algorithms O
for O
combinatorial B-KEY
auctions I-KEY
are O
centralized O
. O
The O
PAUSE B-KEY
auction I-KEY
is O
one O
of O
a O
few O
efforts O
to O
release O
the O
auctioneer O
from O
having O
to O
do O
all O
the O
work O
-LRB- O
it O
might O
even O
be O
possible O
to O
get O
rid O
of O
the O
auctioneer O
-RRB- O
. O
It O
is O
an O
increasing O
price O
combinatorial B-KEY
auction I-KEY
that O
naturally O
distributes O
the O
problem O
of O
winner O
determination O
amongst O
the O
bidders O
in O
such O
a O
way O
that O
they O
have O
an O
incentive O
to O
perform O
the O
calculation O
. O
It O
can O
be O
used O
when O
we O
wish O
to O
distribute O
the O
computational O
load O
among O
the O
bidders O
or O
when O
the O
bidders O
do O
not O
wish O
to O
reveal O
their O
true O
valuations O
unless O
necessary O
. O
PAUSE O
establishes O
the O
rules O
the O
bidders O
must O
obey O
. O
However O
, O
it O
does O
not O
tell O
us O
how O
the O
bidders O
should O
calculate O
their O
bids O
. O
We O
have O
developed O
a O
couple O
of O
bidding B-KEY
algorithms I-KEY
for O
the O
bidders O
in O
a O
PAUSE B-KEY
auction I-KEY
. O
Our O
algorithms O
always O
return O
the O
set O
of O
bids O
that O
maximizes O
the O
bidder O
's O
utility O
. O
Since O
the O
problem O
is O
NP-Hard O
, O
run O
time O
remains O
exponential O
on O
the O
number O
of O
items O
, O
but O
it O
is O
remarkably O
better O
than O
an O
exhaustive O
search O
. O
In O
this O
paper O
we O
present O
our O
bidding B-KEY
algorithms I-KEY
, O
discuss O
their O
virtues O
and O
drawbacks O
, O
and O
compare O
the O
solutions O
obtained O
by O
them O
to O
the O
revenue-maximizing O
solution O
found O
by O
a O
centralized O
winner O
determination O
algorithm O
. O
Unifying O
Distributed O
Constraint B-KEY
Algorithms B-KEY
in O
a O
BDI B-KEY
Negotiation B-KEY
Framework O
ABSTRACT O
This O
paper O
presents O
a O
novel O
, O
unified O
distributed O
constraint B-KEY
satisfaction O
framework O
based O
on O
automated O
negotiation B-KEY
. O
The O
Distributed O
Constraint B-KEY
Satisfaction O
Problem O
-LRB- O
DCSP O
-RRB- O
is O
one O
that O
entails O
several O
agents O
to O
search O
for O
an O
agreement O
, O
which O
is O
a O
consistent O
combination O
of O
actions O
that O
satisfies O
their O
mutual O
constraints O
in O
a O
shared O
environment O
. O
By O
anchoring O
the O
DCSP B-KEY
search O
on O
automated O
negotiation B-KEY
, O
we O
show O
that O
several O
well-known O
DCSP B-KEY
algorithms B-KEY
are O
actually O
mechanisms O
that O
can O
reach O
agreements O
through O
a O
common O
Belief-Desire-Intention O
-LRB- O
BDI B-KEY
-RRB- O
protocol O
, O
but O
using O
different O
strategies O
. O
A O
major O
motivation O
for O
this O
BDI B-KEY
framework O
is O
that O
it O
not O
only O
provides O
a O
conceptually O
clearer O
understanding O
of O
existing O
DCSP B-KEY
algorithms B-KEY
from O
an O
agent O
model O
perspective O
, O
but O
also O
opens O
up O
the O
opportunities O
to O
extend O
and O
develop O
new O
strategies O
for O
DCSP B-KEY
. O
To O
this O
end O
, O
a O
new O
strategy O
called O
Unsolicited O
Mutual O
Advice O
-LRB- O
UMA B-KEY
-RRB- O
is O
proposed O
. O
Performance O
evaluation O
shows O
that O
the O
UMA B-KEY
strategy O
can O
outperform O
some O
existing O
mechanisms O
in O
terms O
of O
computational O
cycles O
. O
Assured O
Service O
Quality O
by O
Improved O
Fault B-KEY
Management I-KEY
Service-Oriented O
Event B-KEY
Correlation I-KEY
ABSTRACT O
The O
paradigm O
shift O
from O
device-oriented O
to O
service-oriented O
management O
has O
also O
implications O
to O
the O
area O
of O
event B-KEY
correlation I-KEY
. O
Today O
's O
event B-KEY
correlation I-KEY
mainly O
addresses O
the O
correlation O
of O
events O
as O
reported O
from O
management O
tools O
. O
However O
, O
a O
correlation O
of O
user O
trouble O
reports O
concerning O
services O
should O
also O
be O
performed O
. O
This O
is O
necessary O
to O
improve O
the O
resolution O
time O
and O
to O
reduce O
the O
effort O
for O
keeping O
the O
service O
agreements O
. O
We O
refer O
to O
such O
a O
type O
of O
correlation O
as O
service-oriented O
event B-KEY
correlation I-KEY
. O
The O
necessity O
to O
use O
this O
kind O
of O
event B-KEY
correlation I-KEY
is O
motivated O
in O
the O
paper O
. O
To O
introduce O
service-oriented O
event B-KEY
correlation I-KEY
for O
an O
IT O
service O
provider O
, O
an O
appropriate O
modeling O
of O
the O
correlation O
workflow O
and O
of O
the O
information O
is O
necessary O
. O
Therefore O
, O
we O
examine O
the O
process B-KEY
management I-KEY
frameworks I-KEY
IT O
Infrastructure O
Library O
-LRB- O
ITIL O
-RRB- O
and O
enhanced O
Telecom O
Operations O
Map O
-LRB- O
eTOM O
-RRB- O
for O
their O
contribution O
to O
the O
workflow O
modeling O
in O
this O
area O
. O
The O
different O
kinds O
of O
dependencies O
that O
we O
find O
in O
our O
general O
scenario O
are O
then O
used O
to O
develop O
a O
workflow O
for O
the O
service-oriented O
event B-KEY
correlation I-KEY
. O
The O
MNM O
Service O
Model O
, O
which O
is O
a O
generic O
model O
for O
IT O
service B-KEY
management I-KEY
proposed O
by O
the O
Munich O
Network O
Management O
-LRB- O
MNM O
-RRB- O
Team O
, O
is O
used O
to O
derive O
an O
appropriate O
information O
modeling O
. O
An O
example O
scenario O
, O
the O
Web O
Hosting O
Service O
of O
the O
Leibniz O
Supercomputing O
Center O
-LRB- O
LRZ O
-RRB- O
, O
is O
used O
to O
demonstrate O
the O
application O
of O
service-oriented O
event B-KEY
correlation I-KEY
. O
Applying O
Learning B-KEY
Algorithms O
to O
Preference O
Elicitation O
ABSTRACT O
We O
consider O
the O
parallels B-KEY
between O
the O
preference B-KEY
elicitation I-KEY
problem O
in O
combinatorial O
auctions O
and O
the O
problem O
of O
learning O
an O
unknown O
function O
from O
learning O
theory O
. O
We O
show O
that O
learning B-KEY
algorithms O
can O
be O
used O
as O
a O
basis O
for O
preference O
elicitation O
algorithms O
. O
The O
resulting O
elicitation B-KEY
algorithms I-KEY
perform O
a O
polynomial B-KEY
number O
of O
queries O
. O
We O
also O
give O
conditions O
under O
which O
the O
resulting B-KEY
algorithms I-KEY
have O
polynomial B-KEY
communication O
. O
Our O
conversion B-KEY
procedure I-KEY
allows O
us O
to O
generate O
combinatorial B-KEY
auction I-KEY
protocols O
from O
learning O
algorithms O
for O
polynomials O
, O
monotone O
DNF O
, O
and O
linear-threshold O
functions O
. O
In O
particular O
, O
we O
obtain O
an O
algorithm O
that O
elicits O
XOR B-KEY
bids I-KEY
with O
polynomial B-KEY
communication O
. O
Query B-KEY
Performance I-KEY
Prediction I-KEY
in O
Web B-KEY
Search I-KEY
Environments O
ABSTRACT O
Current O
prediction O
techniques O
, O
which O
are O
generally O
designed O
for O
content-based O
queries O
and O
are O
typically O
evaluated O
on O
relatively O
homogenous B-KEY
test I-KEY
collections I-KEY
of O
small O
sizes O
, O
face O
serious O
challenges O
in O
web B-KEY
search I-KEY
environments O
where O
collections O
are O
significantly O
more O
heterogeneous O
and O
different O
types O
of O
retrieval O
tasks O
exist O
. O
In O
this O
paper O
, O
we O
present O
three O
techniques O
to O
address O
these O
challenges O
. O
We O
focus O
on O
performance O
prediction O
for O
two O
types O
of O
queries O
in O
web B-KEY
search I-KEY
environments O
: O
content-based O
and O
Named-Page O
finding O
. O
Our O
evaluation O
is O
mainly O
performed O
on O
the O
GOV2 B-KEY
collection I-KEY
. O
In O
addition O
to O
evaluating O
our O
models O
for O
the O
two O
types O
of O
queries O
separately O
, O
we O
consider O
a O
more O
challenging O
and O
realistic O
situation O
that O
the O
two O
types O
of O
queries O
are O
mixed O
together O
without O
prior O
information O
on O
query O
types O
. O
To O
assist O
prediction O
under O
the O
mixed-query O
situation O
, O
a O
novel O
query O
classifier O
is O
adopted O
. O
Results O
show O
that O
our O
prediction O
of O
web O
query O
performance O
is O
substantially O
more O
accurate O
than O
the O
current O
stateof-the-art O
prediction O
techniques O
. O
Consequently O
, O
our O
paper O
provides O
a O
practical O
approach O
to O
performance O
prediction O
in O
realworld O
web O
settings O
. O
A O
Semantic B-KEY
Approach O
to O
Contextual B-KEY
Advertising I-KEY
ABSTRACT O
Contextual B-KEY
advertising I-KEY
or O
Context O
Match B-KEY
-LRB- O
CM O
-RRB- O
refers O
to O
the O
placement O
of O
commercial O
textual O
advertisements O
within O
the O
content O
of O
a O
generic O
web O
page O
, O
while O
Sponsored O
Search O
-LRB- O
SS O
-RRB- O
advertising O
consists O
in O
placing O
ads O
on O
result O
pages O
from O
a O
web O
search O
engine O
, O
with O
ads O
driven O
by O
the O
originating O
query O
. O
In O
CM O
there O
is O
usually O
an O
intermediary O
commercial O
ad-network O
entity O
in O
charge O
of O
optimizing O
the O
ad O
selection O
with O
the O
twin O
goal O
of O
increasing O
revenue O
-LRB- O
shared O
between O
the O
publisher O
and O
the O
ad-network O
-RRB- O
and O
improving O
the O
user O
experience O
. O
With O
these O
goals O
in O
mind O
it O
is O
preferable O
to O
have O
ads B-KEY
relevant I-KEY
to O
the O
page O
content O
, O
rather O
than O
generic O
ads O
. O
The O
SS O
market O
developed O
quicker O
than O
the O
CM O
market O
, O
and O
most O
textual O
ads O
are O
still O
characterized O
by O
`` O
bid O
phrases O
'' O
representing O
those O
queries O
where O
the O
advertisers O
would O
like O
to O
have O
their O
ad O
displayed O
. O
Hence O
, O
the O
first O
technologies O
for O
CM O
have O
relied O
on O
previous O
solutions O
for O
SS O
, O
by O
simply O
extracting O
one O
or O
more O
phrases O
from O
the O
given O
page O
content O
, O
and O
displaying O
ads O
corresponding O
to O
searches O
on O
these O
phrases O
, O
in O
a O
purely O
syntactic O
approach O
. O
However O
, O
due O
to O
the O
vagaries O
of O
phrase O
extraction O
, O
and O
the O
lack O
of O
context O
, O
this O
approach O
leads O
to O
many O
irrelevant O
ads O
. O
To O
overcome O
this O
problem O
, O
we O
propose O
a O
system O
for O
contextual O
ad O
matching B-KEY
based O
on O
a O
combination O
of O
semantic B-KEY
and O
syntactic O
features O
. O
ICE O
: O
An O
Iterative B-KEY
Combinatorial I-KEY
Exchange I-KEY
David O
C. O
Parkes O
* O
s O
Ruggiero O
Cavallos O
Nick O
Elprins O
Adam O
Judas O
S O
´ O
ebastien O
Lahaies O
ABSTRACT O
We O
present O
the O
first O
design O
for O
an O
iterative B-KEY
combinatorial I-KEY
exchange I-KEY
-LRB- O
ICE O
-RRB- O
. O
The O
exchange O
incorporates O
a O
tree-based O
bidding B-KEY
language O
that O
is O
concise O
and O
expressive O
for O
CEs O
. O
Bidders O
specify O
lower O
and O
upper O
bounds O
on O
their O
value O
for O
different O
trades B-KEY
. O
These O
bounds O
allow O
price B-KEY
discovery O
and O
useful O
preference B-KEY
elicitation I-KEY
in O
early O
rounds O
, O
and O
allow O
termination O
with O
an O
efficient O
trade B-KEY
despite O
partial O
information O
on O
bidder O
valuations O
. O
All O
computation O
in O
the O
exchange O
is O
carefully O
optimized O
to O
exploit O
the O
structure O
of O
the O
bid-trees O
and O
to O
avoid O
enumerating O
trades O
. O
A O
proxied O
interpretation O
of O
a O
revealedpreference O
activity O
rule O
ensures O
progress O
across O
rounds O
. O
A O
VCG-based O
payment O
scheme O
that O
has O
been O
shown O
to O
mitigate O
opportunities O
for O
bargaining O
and O
strategic O
behavior O
is O
used O
to O
determine O
final O
payments O
. O
The O
exchange O
is O
fully O
implemented O
and O
in O
a O
validation O
phase O
. O
Normative B-KEY
System I-KEY
Games O
ABSTRACT O
We O
develop O
a O
model O
of O
normative B-KEY
systems I-KEY
in O
which O
agents O
are O
assumed O
to O
have O
multiple O
goals B-KEY
of O
increasing O
priority O
, O
and O
investigate O
the O
computational O
complexity O
and O
game O
theoretic O
properties O
of O
this O
model O
. O
In O
the O
underlying O
model O
of O
normative B-KEY
systems I-KEY
, O
we O
use O
Kripke B-KEY
structures I-KEY
to O
represent O
the O
possible O
transitions O
of O
a O
multiagent O
system O
. O
A O
normative B-KEY
system I-KEY
is O
then O
simply O
a O
subset O
of O
the O
Kripke B-KEY
structure I-KEY
, O
which O
contains O
the O
arcs O
that O
are O
forbidden O
by O
the O
normative B-KEY
system I-KEY
. O
We O
specify O
an O
agent O
's O
goals B-KEY
as O
a O
hierarchy O
of O
formulae O
of O
Computation B-KEY
Tree I-KEY
Logic I-KEY
-LRB- O
CTL O
-RRB- O
, O
a O
widely O
used O
logic O
for O
representing O
the O
properties O
of O
Kripke O
structures O
: O
the O
intuition O
is O
that O
goals O
further O
up O
the O
hierarchy O
are O
preferred O
by O
the O
agent O
over O
those O
that O
appear O
further O
down O
the O
hierarchy O
. O
Using O
this O
scheme O
, O
we O
define O
a O
model O
of O
ordinal B-KEY
utility I-KEY
, O
which O
in O
turn O
allows O
us O
to O
interpret O
our O
Kripke-based O
normative B-KEY
systems I-KEY
as O
games B-KEY
, O
in O
which O
agents O
must O
determine O
whether O
to O
comply O
with O
the O
normative B-KEY
system I-KEY
or O
not O
. O
We O
then O
characterise O
the O
computational B-KEY
complexity I-KEY
of O
a O
number O
of O
decision O
problems O
associated O
with O
these O
Kripke-based O
normative O
system O
games O
; O
for O
example O
, O
we O
show O
that O
the O
complexity O
of O
checking O
whether O
there O
exists O
a O
normative O
system O
which O
has O
the O
property O
of O
being O
a O
Nash O
implementation O
is O
NP-complete O
. O
Complexity O
of O
-LRB- O
Iterated O
-RRB- O
Dominance B-KEY
* O
ABSTRACT O
We O
study O
various O
computational O
aspects O
of O
solving O
games O
using O
dominance B-KEY
and O
iterated B-KEY
dominance I-KEY
. O
We O
first O
study O
both O
strict O
and O
weak O
dominance B-KEY
-LRB- O
not O
iterated O
-RRB- O
, O
and O
show O
that O
checking O
whether O
a O
given O
strategy B-KEY
is O
dominated B-KEY
by O
some O
mixed O
strategy B-KEY
can O
be O
done O
in O
polynomial O
time O
using O
a O
single O
linear O
program O
solve O
. O
We O
then O
move O
on O
to O
iterated B-KEY
dominance I-KEY
. O
We O
show O
that O
determining O
whether O
there O
is O
some O
path O
that O
eliminates B-KEY
a O
given O
strategy B-KEY
is O
NP-complete O
with O
iterated O
weak O
dominance B-KEY
. O
This O
allows O
us O
to O
also O
show O
that O
determining O
whether O
there O
is O
a O
path O
that O
leads O
to O
a O
unique O
solution O
is O
NP-complete O
. O
Both O
of O
these O
results O
hold O
both O
with O
and O
without O
dominance B-KEY
by O
mixed O
strategies B-KEY
. O
-LRB- O
A O
weaker O
version O
of O
the O
second O
result O
-LRB- O
only O
without O
dominance B-KEY
by O
mixed O
strategies B-KEY
-RRB- O
was O
already O
known O
-LSB- O
7 O
-RSB- O
. O
-RRB- O
Iterated O
strict O
dominance B-KEY
, O
on O
the O
other O
hand O
, O
is O
path-independent O
-LRB- O
both O
with O
and O
without O
dominance B-KEY
by O
mixed O
strategies B-KEY
-RRB- O
and O
can O
therefore O
be O
done O
in O
polynomial O
time O
. O
We O
then O
study O
what O
happens O
when O
the O
dominating B-KEY
strategy B-KEY
is O
allowed O
to O
place O
positive O
probability O
on O
only O
a O
few O
pure O
strategies B-KEY
. O
First O
, O
we O
show O
that O
finding O
the O
dominating B-KEY
strategy B-KEY
with O
minimum O
support O
size O
is O
NP-complete O
-LRB- O
both O
for O
strict O
and O
weak O
dominance B-KEY
-RRB- O
. O
Then O
, O
we O
show O
that O
iterated O
strict O
dominance B-KEY
becomes O
path-dependent O
when O
there O
is O
a O
limit O
on O
the O
support O
size O
of O
the O
dominating B-KEY
strategies B-KEY
, O
and O
that O
deciding O
whether O
a O
given O
strategy B-KEY
can O
be O
eliminated B-KEY
by O
iterated O
strict O
dominance B-KEY
under O
this O
restriction O
is O
NP-complete O
-LRB- O
even O
when O
the O
limit O
on O
the O
support O
size O
is O
3 O
-RRB- O
. O
Finally O
, O
we O
study O
Bayesian B-KEY
games I-KEY
. O
We O
show O
that O
, O
unlike O
in O
normal B-KEY
form I-KEY
games I-KEY
, O
deciding O
whether O
a O
given O
pure O
strategy B-KEY
is O
dominated B-KEY
by O
another O
pure O
strategy B-KEY
in O
a O
Bayesian B-KEY
game I-KEY
is O
NP-complete O
-LRB- O
both O
with O
strict O
and O
weak O
dominance B-KEY
-RRB- O
; O
however O
, O
deciding O
whether O
a O
strategy B-KEY
is O
dominated B-KEY
by O
some O
mixed O
strategy B-KEY
can O
still O
be O
done O
in O
polynomial O
time O
with O
a O
single O
linear O
program O
solve O
-LRB- O
both O
with O
strict O
and O
weak O
* O
This O
material O
is O
based O
upon O
work O
supported O
by O
the O
National O
Science O
Foundation O
under O
ITR O
grants O
IIS-0121678 O
and O
IIS-0427858 O
, O
and O
a O
Sloan O
Fellowship O
. O
dominance B-KEY
-RRB- O
. O
Finally O
, O
we O
show O
that O
iterated B-KEY
dominance I-KEY
using O
pure O
strategies O
can O
require O
an O
exponential O
number O
of O
iterations O
in O
a O
Bayesian O
game O
-LRB- O
both O
with O
strict O
and O
weak O
dominance O
-RRB- O
. O
A O
Scalable O
Distributed O
Information B-KEY
Management I-KEY
System I-KEY
* O
We O
present O
a O
Scalable O
Distributed O
Information B-KEY
Management I-KEY
System I-KEY
-LRB- O
SDIMS O
-RRB- O
that O
aggregates O
information O
about O
large-scale O
networked O
systems O
and O
that O
can O
serve O
as O
a O
basic O
building O
block O
for O
a O
broad O
range O
of O
large-scale O
distributed O
applications O
by O
providing O
detailed O
views O
of O
nearby O
information O
and O
summary O
views O
of O
global O
information O
. O
To O
serve O
as O
a O
basic O
building O
block O
, O
a O
SDIMS O
should O
have O
four O
properties O
: O
scalability O
to O
many O
nodes O
and O
attributes O
, O
flexibility O
to O
accommodate O
a O
broad O
range O
of O
applications O
, O
administrative B-KEY
isolation I-KEY
for O
security O
and O
availability B-KEY
, O
and O
robustness O
to O
node O
and O
network O
failures O
. O
We O
design O
, O
implement O
and O
evaluate O
a O
SDIMS O
that O
-LRB- O
1 O
-RRB- O
leverages O
Distributed B-KEY
Hash I-KEY
Tables I-KEY
-LRB- O
DHT O
-RRB- O
to O
create O
scalable O
aggregation O
trees O
, O
-LRB- O
2 O
-RRB- O
provides O
flexibility O
through O
a O
simple O
API O
that O
lets O
applications O
control O
propagation O
of O
reads O
and O
writes O
, O
-LRB- O
3 O
-RRB- O
provides O
administrative B-KEY
isolation I-KEY
through O
simple O
extensions O
to O
current O
DHT O
algorithms O
, O
and O
-LRB- O
4 O
-RRB- O
achieves O
robustness O
to O
node O
and O
network O
reconfigurations O
through O
lazy O
reaggregation O
, O
on-demand O
reaggregation O
, O
and O
tunable B-KEY
spatial I-KEY
replication I-KEY
. O
Through O
extensive O
simulations O
and O
micro-benchmark O
experiments O
, O
we O
observe O
that O
our O
system O
is O
an O
order O
of O
magnitude O
more O
scalable O
than O
existing O
approaches O
, O
achieves O
isolation O
properties O
at O
the O
cost O
of O
modestly O
increased O
read O
latency O
in O
comparison O
to O
flat O
DHTs O
, O
and O
gracefully O
handles O
failures O
. O
Efficiency O
and O
Nash O
Equilibria O
in O
a O
Scrip B-KEY
System I-KEY
for O
P2P B-KEY
Networks I-KEY
ABSTRACT O
A O
model O
of O
providing O
service O
in O
a O
P2P B-KEY
network I-KEY
is O
analyzed O
. O
It O
is O
shown O
that O
by O
adding O
a O
scrip B-KEY
system I-KEY
, O
a O
mechanism O
that O
admits O
a O
reasonable O
Nash B-KEY
equilibrium I-KEY
that O
reduces O
free O
riding O
can O
be O
obtained O
. O
The O
effect O
of O
varying O
the O
total O
amount O
of O
money O
-LRB- O
scrip O
-RRB- O
in O
the O
system O
on O
efficiency O
-LRB- O
i.e. O
, O
social B-KEY
welfare I-KEY
-RRB- O
is O
analyzed O
, O
and O
it O
is O
shown O
that O
by O
maintaining O
the O
appropriate O
ratio O
between O
the O
total O
amount O
of O
money O
and O
the O
number O
of O
agents B-KEY
, O
efficiency O
is O
maximized O
. O
The O
work O
has O
implications O
for O
many O
online B-KEY
systems I-KEY
, O
not O
only O
P2P B-KEY
networks I-KEY
but O
also O
a O
wide O
variety O
of O
online O
forums O
for O
which O
scrip B-KEY
systems I-KEY
are O
popular O
, O
but O
formal O
analyses O
have O
been O
lacking O
. O
Rumours O
and O
Reputation O
: O
Evaluating O
Multi-Dimensional B-KEY
Trust I-KEY
within O
a O
Decentralised O
Reputation B-KEY
System I-KEY
ABSTRACT O
In O
this O
paper O
we O
develop O
a O
novel O
probabilistic O
model O
of O
computational O
trust O
that O
explicitly O
deals O
with O
correlated B-KEY
multi-dimensional O
contracts O
. O
Our O
starting O
point O
is O
to O
consider O
an O
agent O
attempting O
to O
estimate O
the O
utility O
of O
a O
contract O
, O
and O
we O
show O
that O
this O
leads O
to O
a O
model O
of O
computational O
trust O
whereby O
an O
agent O
must O
determine O
a O
vector O
of O
estimates O
that O
represent O
the O
probability O
that O
any O
dimension O
of O
the O
contract O
will O
be O
successfully O
fulfilled O
, O
and O
a O
covariance O
matrix O
that O
describes O
the O
uncertainty O
and O
correlations B-KEY
in O
these O
probabilities O
. O
We O
present O
a O
formalism O
based O
on O
the O
Dirichlet B-KEY
distribution I-KEY
that O
allows O
an O
agent O
to O
calculate O
these O
probabilities O
and O
correlations B-KEY
from O
their O
direct O
experience O
of O
contract O
outcomes O
, O
and O
we O
show O
that O
this O
leads O
to O
superior O
estimates O
compared O
to O
an O
alternative O
approach O
using O
multiple O
independent O
beta O
distributions O
. O
We O
then O
show O
how O
agents O
may O
use O
the O
sufficient O
statistics O
of O
this O
Dirichlet B-KEY
distribution I-KEY
to O
communicate O
and O
fuse O
reputation O
within O
a O
decentralised O
reputation B-KEY
system I-KEY
. O
Finally O
, O
we O
present O
a O
novel O
solution O
to O
the O
problem O
of O
rumour B-KEY
propagation I-KEY
within O
such O
systems O
. O
This O
solution O
uses O
the O
notion O
of O
private O
and O
shared O
information O
, O
and O
provides O
estimates O
consistent O
with O
a O
centralised O
reputation B-KEY
system I-KEY
, O
whilst O
maintaining O
the O
anonymity B-KEY
of O
the O
agents O
, O
and O
avoiding O
bias O
and O
overconfidence B-KEY
. O
Relaxed O
Online O
SVMs O
for O
Spam B-KEY
Filtering I-KEY
ABSTRACT O
Spam O
is O
a O
key O
problem O
in O
electronic O
communication O
, O
including O
large-scale O
email O
systems O
and O
the O
growing O
number O
of O
blogs B-KEY
. O
Content-based O
filtering O
is O
one O
reliable O
method O
of O
combating O
this O
threat O
in O
its O
various O
forms O
, O
but O
some O
academic O
researchers O
and O
industrial O
practitioners O
disagree O
on O
how O
best O
to O
filter O
spam O
. O
The O
former O
have O
advocated O
the O
use O
of O
Support B-KEY
Vector I-KEY
Machines I-KEY
-LRB- O
SVMs O
-RRB- O
for O
content-based O
filtering O
, O
as O
this O
machine O
learning O
methodology O
gives O
state-of-the-art O
performance O
for O
text O
classification O
. O
However O
, O
similar O
performance O
gains O
have O
yet O
to O
be O
demonstrated O
for O
online O
spam B-KEY
filtering I-KEY
. O
Additionally O
, O
practitioners O
cite O
the O
high O
cost O
of O
SVMs O
as O
reason O
to O
prefer O
faster O
-LRB- O
if O
less O
statistically O
robust O
-RRB- O
Bayesian B-KEY
methods I-KEY
. O
In O
this O
paper O
, O
we O
offer O
a O
resolution O
to O
this O
controversy O
. O
First O
, O
we O
show O
that O
online O
SVMs O
indeed O
give O
state-of-the-art O
classification O
performance O
on O
online O
spam B-KEY
filtering I-KEY
on O
large O
benchmark O
data O
sets O
. O
Second O
, O
we O
show O
that O
nearly O
equivalent O
performance O
may O
be O
achieved O
by O
a O
Relaxed O
Online O
SVM O
-LRB- O
ROSVM O
-RRB- O
at O
greatly O
reduced O
computational O
cost O
. O
Our O
results O
are O
experimentally O
verified O
on O
email O
spam O
, O
blog B-KEY
spam O
, O
and O
splog B-KEY
detection O
tasks O
. O
Dynamics B-KEY
Based I-KEY
Control I-KEY
with O
an O
Application O
to O
Area-Sweeping O
Problems O
ABSTRACT O
In O
this O
paper O
we O
introduce O
Dynamics B-KEY
Based I-KEY
Control I-KEY
-LRB- O
DBC O
-RRB- O
, O
an O
approach O
to O
planning O
and O
control O
of O
an O
agent O
in O
stochastic O
environments O
. O
Unlike O
existing O
approaches O
, O
which O
seek O
to O
optimize O
expected O
rewards O
-LRB- O
e.g. O
, O
in O
Partially B-KEY
Observable I-KEY
Markov I-KEY
Decision I-KEY
Problems I-KEY
-LRB- O
POMDPs O
-RRB- O
-RRB- O
, O
DBC O
optimizes O
system O
behavior O
towards O
specified O
system B-KEY
dynamics I-KEY
. O
We O
show O
that O
a O
recently O
developed O
planning O
and O
control B-KEY
approach O
, O
Extended B-KEY
Markov I-KEY
Tracking I-KEY
-LRB- O
EMT O
-RRB- O
is O
an O
instantiation O
of O
DBC O
. O
EMT O
employs O
greedy O
action O
selection O
to O
provide O
an O
efficient O
control B-KEY
algorithm O
in O
Markovian O
environments O
. O
We O
exploit O
this O
efficiency O
in O
a O
set O
of O
experiments O
that O
applied O
multitarget O
EMT O
to O
a O
class O
of O
area-sweeping B-KEY
problems I-KEY
-LRB- O
searching O
for O
moving O
targets O
-RRB- O
. O
We O
show O
that O
such O
problems O
can O
be O
naturally O
defined O
and O
efficiently O
solved O
using O
the O
DBC O
framework O
, O
and O
its O
EMT O
instantiation O
. O
Improving O
Web B-KEY
Search I-KEY
Ranking O
by O
Incorporating O
User O
Behavior O
Information O
ABSTRACT O
We O
show O
that O
incorporating O
user B-KEY
behavior I-KEY
data O
can O
significantly O
improve O
ordering O
of O
top O
results B-KEY
in O
real O
web B-KEY
search I-KEY
setting O
. O
We O
examine O
alternatives O
for O
incorporating O
feedback B-KEY
into O
the O
ranking B-KEY
process O
and O
explore O
the O
contributions O
of O
user O
feedback B-KEY
compared O
to O
other O
common O
web B-KEY
search I-KEY
features O
. O
We O
report O
results B-KEY
of O
a O
large O
scale O
evaluation O
over O
3,000 O
queries O
and O
12 O
million O
user B-KEY
interactions I-KEY
with O
a O
popular O
web B-KEY
search I-KEY
engine O
. O
We O
show O
that O
incorporating O
implicit O
feedback B-KEY
can O
augment O
other O
features O
, O
improving O
the O
accuracy O
of O
a O
competitive O
web B-KEY
search I-KEY
ranking O
algorithms O
by O
as O
much O
as O
31 O
% O
relative O
to O
the O
original O
performance O
. O
Downloading O
Textual O
Hidden B-KEY
Web I-KEY
Content O
Through O
Keyword B-KEY
Queries I-KEY
ABSTRACT O
An O
ever-increasing O
amount O
of O
information O
on O
the O
Web O
today O
is O
available O
only O
through O
search O
interfaces O
: O
the O
users O
have O
to O
type O
in O
a O
set O
of O
keywords O
in O
a O
search O
form O
in O
order O
to O
access O
the O
pages O
from O
certain O
Web O
sites O
. O
These O
pages O
are O
often O
referred O
to O
as O
the O
Hidden B-KEY
Web I-KEY
or O
the O
Deep B-KEY
Web I-KEY
. O
Since O
there O
are O
no O
static O
links O
to O
the O
Hidden B-KEY
Web I-KEY
pages O
, O
search O
engines O
can O
not O
discover O
and O
index O
such O
pages O
and O
thus O
do O
not O
return O
them O
in O
the O
results O
. O
However O
, O
according O
to O
recent O
studies O
, O
the O
content O
provided O
by O
many O
Hidden B-KEY
Web I-KEY
sites O
is O
often O
of O
very O
high O
quality O
and O
can O
be O
extremely O
valuable O
to O
many O
users O
. O
In O
this O
paper O
, O
we O
study O
how O
we O
can O
build O
an O
effective O
Hidden B-KEY
Web I-KEY
crawler O
that O
can O
autonomously O
discover O
and O
download O
pages O
from O
the O
Hidden O
Web O
. O
Since O
the O
only O
`` O
entry O
point O
'' O
to O
a O
Hidden B-KEY
Web I-KEY
site O
is O
a O
query O
interface O
, O
the O
main O
challenge O
that O
a O
Hidden B-KEY
Web I-KEY
crawler O
has O
to O
face O
is O
how O
to O
automatically O
generate O
meaningful O
queries O
to O
issue O
to O
the O
site O
. O
Here O
, O
we O
provide O
a O
theoretical O
framework O
to O
investigate O
the O
query O
generation O
problem O
for O
the O
Hidden B-KEY
Web I-KEY
and O
we O
propose O
effective O
policies O
for O
generating O
queries O
automatically O
. O
Our O
policies O
proceed O
iteratively O
, O
issuing O
a O
different O
query O
in O
every O
iteration O
. O
We O
experimentally O
evaluate O
the O
effectiveness O
of O
these O
policies O
on O
4 O
real O
Hidden B-KEY
Web I-KEY
sites O
and O
our O
results O
are O
very O
promising O
. O
For O
instance O
, O
in O
one O
experiment O
, O
one O
of O
our O
policies O
downloaded O
more O
than O
90 O
% O
of O
a O
Hidden B-KEY
Web I-KEY
site O
-LRB- O
that O
contains O
14 O
million O
documents O
-RRB- O
after O
issuing O
fewer O
than O
100 O
queries O
. O
Unified O
Utility O
Maximization O
Framework O
for O
Resource B-KEY
Selection I-KEY
ABSTRACT O
This O
paper O
presents O
a O
unified O
utility O
framework O
for O
resource B-KEY
selection I-KEY
of O
distributed O
text O
information O
retrieval O
. O
This O
new O
framework O
shows O
an O
efficient O
and O
effective O
way O
to O
infer O
the O
probabilities O
of O
relevance O
of O
all O
the O
documents O
across O
the O
text O
databases O
. O
With O
the O
estimated O
relevance O
information O
, O
resource B-KEY
selection I-KEY
can O
be O
made O
by O
explicitly O
optimizing O
the O
goals O
of O
different O
applications O
. O
Specifically O
, O
when O
used O
for O
database B-KEY
recommendation I-KEY
, O
the O
selection O
is O
optimized O
for O
the O
goal O
of O
highrecall O
-LRB- O
include O
as O
many O
relevant O
documents O
as O
possible O
in O
the O
selected O
databases O
-RRB- O
; O
when O
used O
for O
distributed B-KEY
document I-KEY
retrieval I-KEY
, O
the O
selection O
targets O
the O
high-precision O
goal O
-LRB- O
high O
precision O
in O
the O
final O
merged O
list O
of O
documents O
-RRB- O
. O
This O
new O
model O
provides O
a O
more O
solid O
framework O
for O
distributed B-KEY
information I-KEY
retrieval I-KEY
. O
Empirical O
studies O
show O
that O
it O
is O
at O
least O
as O
effective O
as O
other O
state-of-the-art O
algorithms O
. O
Performance B-KEY
Prediction I-KEY
Using O
Spatial B-KEY
Autocorrelation I-KEY
ABSTRACT O
Evaluation O
of O
information B-KEY
retrieval I-KEY
systems O
is O
one O
of O
the O
core O
tasks O
in O
information B-KEY
retrieval I-KEY
. O
Problems O
include O
the O
inability O
to O
exhaustively O
label O
all O
documents O
for O
a O
topic O
, O
nongeneralizability O
from O
a O
small O
number O
of O
topics O
, O
and O
incorporating O
the O
variability O
of O
retrieval O
systems O
. O
Previous O
work O
addresses O
the O
evaluation O
of O
systems O
, O
the O
ranking B-KEY
of I-KEY
queries I-KEY
by O
difficulty O
, O
and O
the O
ranking O
of O
individual O
retrievals O
by O
performance O
. O
Approaches O
exist O
for O
the O
case O
of O
few O
and O
even O
no O
relevance O
judgments O
. O
Our O
focus O
is O
on O
zero-judgment O
performance B-KEY
prediction I-KEY
of O
individual O
retrievals O
. O
One O
common O
shortcoming O
of O
previous O
techniques O
is O
the O
assumption O
of O
uncorrelated O
document O
scores O
and O
judgments O
. O
If O
documents O
are O
embedded O
in O
a O
high-dimensional O
space O
-LRB- O
as O
they O
often O
are O
-RRB- O
, O
we O
can O
apply O
techniques O
from O
spatial O
data O
analysis O
to O
detect O
correlations O
between O
document O
scores O
. O
We O
find O
that O
the O
low O
correlation O
between O
scores O
of O
topically O
close O
documents O
often O
implies O
a O
poor O
retrieval O
performance O
. O
When O
compared O
to O
a O
state O
of O
the O
art O
baseline O
, O
we O
demonstrate O
that O
the O
spatial O
analysis O
of O
retrieval O
scores O
provides O
significantly O
better O
prediction O
performance O
. O
These O
new O
predictors O
can O
also O
be O
incorporated O
with O
classic O
predictors O
to O
improve O
performance O
further O
. O
We O
also O
describe O
the O
first O
large-scale O
experiment O
to O
evaluate O
zero-judgment O
performance B-KEY
prediction I-KEY
for O
a O
massive O
number O
of O
retrieval O
systems O
over O
a O
variety O
of O
collections O
in O
several O
languages O
. O
Learning O
User O
Interaction O
Models O
for O
Predicting O
Web O
Search O
Result O
Preferences O
ABSTRACT O
Evaluating O
user B-KEY
preferences I-KEY
of O
web O
search O
results O
is O
crucial O
for O
search O
engine O
development O
, O
deployment O
, O
and O
maintenance O
. O
We O
present O
a O
real-world O
study O
of O
modeling O
the O
behavior O
of O
web O
search O
users O
to O
predict O
web O
search O
result O
preferences O
. O
Accurate O
modeling O
and O
interpretation O
of O
user O
behavior O
has O
important O
applications O
to O
ranking O
, O
click B-KEY
spam I-KEY
detection I-KEY
, O
web O
search O
personalization B-KEY
, O
and O
other O
tasks O
. O
Our O
key O
insight O
to O
improving O
robustness O
of O
interpreting O
implicit B-KEY
feedback I-KEY
is O
to O
model O
query-dependent O
deviations O
from O
the O
expected O
`` O
noisy O
'' O
user O
behavior O
. O
We O
show O
that O
our O
model O
of O
clickthrough B-KEY
interpretation O
improves O
prediction O
accuracy O
over O
state-of-the-art O
clickthrough B-KEY
methods O
. O
We O
generalize O
our O
approach O
to O
model O
user O
behavior O
beyond O
clickthrough B-KEY
, O
which O
results O
in O
higher O
preference O
prediction O
accuracy O
than O
models O
based O
on O
clickthrough B-KEY
information O
alone O
. O
We O
report O
results O
of O
a O
large-scale O
experimental O
evaluation O
that O
show O
substantial O
improvements O
over O
published O
implicit B-KEY
feedback I-KEY
interpretation O
methods O
. O
Robust B-KEY
Solutions O
for O
Combinatorial B-KEY
Auctions I-KEY
* O
ABSTRACT O
Bids B-KEY
submitted O
in O
auctions O
are O
usually O
treated O
as O
enforceable B-KEY
commitments I-KEY
in O
most O
bidding B-KEY
and O
auction O
theory O
literature O
. O
In O
reality O
bidders O
often O
withdraw O
winning O
bids B-KEY
before O
the O
transaction O
when O
it O
is O
in O
their O
best O
interests O
to O
do O
so O
. O
Given O
a O
bid B-KEY
withdrawal O
in O
a O
combinatorial O
auction O
, O
finding O
an O
alternative O
repair O
solution O
of O
adequate O
revenue O
without O
causing O
undue O
disturbance O
to O
the O
remaining O
winning O
bids O
in O
the O
original O
solution O
may O
be O
difficult O
or O
even O
impossible O
. O
We O
have O
called O
this O
the O
`` O
Bid-taker O
's O
Exposure O
Problem O
'' O
. O
When O
faced O
with O
such O
unreliable O
bidders O
, O
it O
is O
preferable O
for O
the O
bid-taker O
to O
preempt O
such O
uncertainty O
by O
having O
a O
solution O
that O
is O
robust O
to O
bid O
withdrawal O
and O
provides O
a O
guarantee O
that O
possible O
withdrawals O
may O
be O
repaired O
easily O
with O
a O
bounded O
loss O
in O
revenue O
. O
In O
this O
paper O
, O
we O
propose O
an O
approach O
to O
addressing O
the O
Bidtaker O
's O
Exposure B-KEY
Problem I-KEY
. O
Firstly O
, O
we O
use O
the O
Weighted B-KEY
Super I-KEY
Solutions I-KEY
framework O
-LSB- O
13 O
-RSB- O
, O
from O
the O
field O
of O
constraint B-KEY
programming I-KEY
, O
to O
solve O
the O
problem O
of O
finding O
a O
robust B-KEY
solution O
. O
A O
weighted B-KEY
super I-KEY
solution I-KEY
guarantees O
that O
any O
subset O
of O
bids B-KEY
likely O
to O
be O
withdrawn O
can O
be O
repaired O
to O
form O
a O
new O
solution O
of O
at O
least O
a O
given O
revenue O
by O
making O
limited O
changes O
. O
Secondly O
, O
we O
introduce O
an O
auction O
model O
that O
uses O
a O
form O
of O
leveled O
commitment O
contract O
-LSB- O
26 O
, O
27 O
-RSB- O
, O
which O
we O
have O
called O
mutual O
bid B-KEY
bonds O
, O
to O
improve O
solution O
reparability O
by O
facilitating O
backtracking O
on O
winning O
bids O
by O
the O
bid-taker O
. O
We O
then O
examine O
the O
trade-off O
between O
robustness B-KEY
and O
revenue O
in O
different O
economically O
motivated O
auction O
scenarios O
for O
different O
constraints O
on O
the O
revenue O
of O
repair O
solutions O
. O
We O
also O
demonstrate O
experimentally O
that O
fewer O
winning O
bids B-KEY
partake O
in O
robust B-KEY
solutions O
, O
thereby O
reducing O
any O
associated O
overhead O
in O
dealing O
with O
extra O
bidders O
. O
Robust B-KEY
solutions O
can O
also O
provide O
a O
means O
of O
selectively O
discriminating O
against O
distrusted O
bidders O
in O
a O
measured O
manner O
. O
HITS B-KEY
Hits B-KEY
TREC B-KEY
-- O
Exploring O
IR B-KEY
Evaluation I-KEY
Results O
with O
Network B-KEY
Analysis I-KEY
ABSTRACT O
We O
propose O
a O
novel O
method O
of O
analysing O
data O
gathered O
from O
TREC B-KEY
or O
similar O
information B-KEY
retrieval I-KEY
evaluation I-KEY
experiments I-KEY
. O
We O
define O
two O
normalized O
versions O
of O
average O
precision O
, O
that O
we O
use O
to O
construct O
a O
weighted B-KEY
bipartite I-KEY
graph I-KEY
of O
TREC B-KEY
systems O
and O
topics O
. O
We O
analyze O
the O
meaning O
of O
well O
known O
-- O
and O
somewhat O
generalized O
-- O
indicators O
from O
social B-KEY
network I-KEY
analysis I-KEY
on O
the O
Systems-Topics O
graph O
. O
We O
apply O
this O
method O
to O
an O
analysis O
of O
TREC B-KEY
8 O
data O
; O
among O
the O
results O
, O
we O
find O
that O
authority O
measures O
systems O
performance O
, O
that O
hubness O
of O
topics O
reveals O
that O
some O
topics O
are O
better O
than O
others O
at O
distinguishing O
more O
or O
less O
effective O
systems O
, O
that O
with O
current O
measures O
a O
system O
that O
wants O
to O
be O
effective O
in O
TREC B-KEY
needs O
to O
be O
effective O
on O
easy O
topics O
, O
and O
that O
by O
using O
different O
effectiveness O
measures O
this O
is O
no O
longer O
the O
case O
. O
Learning O
and O
Joint B-KEY
Deliberation I-KEY
through O
Argumentation B-KEY
in O
Multi-Agent O
Systems O
ABSTRACT O
In O
this O
paper O
we O
will O
present O
an O
argumentation B-KEY
framework O
for O
learning O
agents O
-LRB- O
AMAL O
-RRB- O
designed O
for O
two O
purposes O
: O
-LRB- O
1 O
-RRB- O
for O
joint O
deliberation O
, O
and O
-LRB- O
2 O
-RRB- O
for O
learning O
from O
communication O
. O
The O
AMAL O
framework O
is O
completely O
based O
on O
learning O
from O
examples O
: O
the O
argument B-KEY
preference O
relation O
, O
the O
argument B-KEY
generation O
policy O
, O
and O
the O
counterargument O
generation O
policy O
are O
case-based O
techniques O
. O
For O
join O
deliberation O
, O
learning B-KEY
agents I-KEY
share O
their O
experience O
by O
forming O
a O
committee O
to O
decide O
upon O
some O
joint O
decision O
. O
We O
experimentally O
show O
that O
the O
argumentation B-KEY
among O
committees O
of O
agents O
improves O
both O
the O
individual O
and O
joint O
performance O
. O
For O
learning B-KEY
from I-KEY
communication I-KEY
, O
an O
agent O
engages O
into O
arguing O
with O
other O
agents O
in O
order O
to O
contrast O
its O
individual O
hypotheses O
and O
receive O
counterexamples O
; O
the O
argumentation B-KEY
process O
improves O
their O
learning O
scope O
and O
individual O
performance O
. O
Expressive B-KEY
Negotiation I-KEY
over O
Donations B-KEY
to I-KEY
Charities I-KEY
∗ O
ABSTRACT O
When O
donating O
money O
to O
a O
-LRB- O
say O
, O
charitable O
-RRB- O
cause O
, O
it O
is O
possible O
to O
use O
the O
contemplated O
donation O
as O
negotiating B-KEY
material I-KEY
to O
induce O
other O
parties O
interested O
in O
the O
charity O
to O
donate O
more O
. O
Such O
negotiation O
is O
usually O
done O
in O
terms O
of O
matching O
offers O
, O
where O
one O
party O
promises O
to O
pay O
a O
certain O
amount O
if O
others O
pay O
a O
certain O
amount O
. O
However O
, O
in O
their O
current O
form O
, O
matching O
offers O
allow O
for O
only O
limited O
negotiation O
. O
For O
one O
, O
it O
is O
not O
immediately O
clear O
how O
multiple O
parties O
can O
make O
matching O
offers O
at O
the O
same O
time O
without O
creating O
circular O
dependencies O
. O
Also O
, O
it O
is O
not O
immediately O
clear O
how O
to O
make O
a O
donation O
conditional O
on O
other O
donations O
to O
multiple O
charities O
, O
when O
the O
donator O
has O
different O
levels O
of O
appreciation O
for O
the O
different O
charities O
. O
In O
both O
these O
cases O
, O
the O
limited O
expressiveness O
of O
matching O
offers O
causes O
economic O
loss O
: O
it O
may O
happen O
that O
an O
arrangement O
that O
would O
have O
made O
all O
parties O
-LRB- O
donators O
as O
well O
as O
charities O
-RRB- O
better O
off O
can O
not O
be O
expressed O
in O
terms O
of O
matching O
offers O
and O
will O
therefore O
not O
occur O
. O
In O
this O
paper O
, O
we O
introduce O
a O
bidding B-KEY
language I-KEY
for O
expressing O
very O
general O
types O
of O
matching O
offers O
over O
multiple O
charities O
. O
We O
formulate O
the O
corresponding O
clearing O
problem O
-LRB- O
deciding O
how O
much O
each O
bidder O
pays O
, O
and O
how O
much O
each O
charity O
receives O
-RRB- O
, O
and O
show O
that O
it O
is O
NP-complete O
to O
approximate O
to O
any O
ratio O
even O
in O
very O
restricted O
settings O
. O
We O
give O
a O
mixed-integer O
program O
formulation O
of O
the O
clearing O
problem O
, O
and O
show O
that O
for O
concave B-KEY
bids I-KEY
, O
the O
program O
reduces O
to O
a O
linear B-KEY
program I-KEY
. O
We O
then O
show O
that O
the O
clearing O
problem O
for O
a O
subclass O
of O
concave B-KEY
bids I-KEY
is O
at O
least O
as O
hard O
as O
the O
decision O
variant O
of O
linear B-KEY
programming I-KEY
. O
Subsequently O
, O
we O
show O
that O
the O
clearing O
problem O
is O
much O
easier O
when O
bids O
are O
quasilinear B-KEY
-- O
for O
surplus O
, O
the O
problem O
decomposes O
across O
charities O
, O
and O
for O
payment O
maximization O
, O
a O
greedy O
approach O
is O
optimal O
if O
the O
bids O
are O
concave O
-LRB- O
although O
this O
latter O
problem O
is O
weakly O
NP-complete O
when O
the O
bids O
are O
not O
concave O
-RRB- O
. O
For O
the O
quasilinear B-KEY
setting O
, O
we O
study O
the O
mechanism B-KEY
design I-KEY
question O
. O
We O
show O
that O
an O
ex-post O
efficient O
mechanism O
is O
∗ O
Supported O
by O
NSF O
under O
CAREER O
Award O
IRI-9703122 O
, O
Grant O
IIS-9800994 O
, O
ITR O
IIS-0081246 O
, O
and O
ITR O
IIS-0121678 O
. O
impossible O
even O
with O
only O
one O
charity O
and O
a O
very O
restricted O
class O
of O
bids O
. O
We O
also O
show O
that O
there O
may O
be O
benefits O
to O
linking O
the O
charities O
from O
a O
mechanism B-KEY
design I-KEY
standpoint O
. O
Location O
based O
Indexing B-KEY
Scheme O
for O
DAYS O
ABSTRACT O
Data O
dissemination O
through O
wireless B-KEY
channels I-KEY
for O
broadcasting O
information O
to O
consumers O
is O
becoming O
quite O
common O
. O
Many O
dissemination O
schemes O
have O
been O
proposed O
but O
most O
of O
them O
push O
data O
to O
wireless B-KEY
channels I-KEY
for O
general O
consumption O
. O
Push O
based O
broadcast O
-LSB- O
1 O
-RSB- O
is O
essentially O
asymmetric O
, O
i.e. O
, O
the O
volume O
of O
data O
being O
higher O
from O
the O
server O
to O
the O
users O
than O
from O
the O
users O
back O
to O
the O
server O
. O
Push O
based O
scheme O
requires O
some O
indexing B-KEY
which O
indicates O
when O
the O
data O
will O
be O
broadcast O
and O
its O
position O
in O
the O
broadcast O
. O
Access O
latency O
and O
tuning O
time O
are O
the O
two O
main O
parameters O
which O
may O
be O
used O
to O
evaluate O
an O
indexing B-KEY
scheme O
. O
Two O
of O
the O
important O
indexing B-KEY
schemes O
proposed O
earlier O
were O
tree O
based O
and O
the O
exponential O
indexing O
schemes O
. O
None O
of O
these O
schemes O
were O
able O
to O
address O
the O
requirements O
of O
location B-KEY
dependent I-KEY
data I-KEY
-LRB- O
LDD B-KEY
-RRB- O
which O
is O
highly O
desirable O
feature O
of O
data O
dissemination O
. O
In O
this O
paper O
, O
we O
discuss O
the O
broadcast O
of O
LDD B-KEY
in O
our O
project O
DAta O
in O
Your O
Space O
-LRB- O
DAYS O
-RRB- O
, O
and O
propose O
a O
scheme O
for O
indexing B-KEY
LDD B-KEY
. O
We O
argue O
that O
this O
scheme O
, O
when O
applied O
to O
LDD B-KEY
, O
significantly O
improves O
performance O
in O
terms O
of O
tuning O
time O
over O
the O
above O
mentioned O
schemes O
. O
We O
prove O
our O
argument O
with O
the O
help O
of O
simulation O
results O
. O
Vocabulary B-KEY
Independent O
Spoken B-KEY
Term I-KEY
Detection I-KEY
ABSTRACT O
We O
are O
interested O
in O
retrieving O
information O
from O
speech O
data O
like O
broadcast O
news O
, O
telephone O
conversations O
and O
roundtable O
meetings O
. O
Today O
, O
most O
systems O
use O
large O
vocabulary B-KEY
continuous O
speech O
recognition O
tools O
to O
produce O
word O
transcripts O
; O
the O
transcripts O
are O
indexed O
and O
query O
terms O
are O
retrieved O
from O
the O
index O
. O
However O
, O
query O
terms O
that O
are O
not O
part O
of O
the O
recognizer O
's O
vocabulary B-KEY
can O
not O
be O
retrieved O
, O
and O
the O
recall O
of O
the O
search O
is O
affected O
. O
In O
addition O
to O
the O
output O
word O
transcript O
, O
advanced O
systems O
provide O
also O
phonetic B-KEY
transcripts I-KEY
, O
against O
which O
query O
terms O
can O
be O
matched O
phonetically O
. O
Such O
phonetic B-KEY
transcripts I-KEY
suffer O
from O
lower O
accuracy O
and O
can O
not O
be O
an O
alternative O
to O
word O
transcripts O
. O
We O
present O
a O
vocabulary B-KEY
independent O
system O
that O
can O
handle O
arbitrary O
queries O
, O
exploiting O
the O
information O
provided O
by O
having O
both O
word O
transcripts O
and O
phonetic O
transcripts O
. O
A O
speech B-KEY
recognizer I-KEY
generates O
word O
confusion O
networks O
and O
phonetic O
lattices O
. O
The O
transcripts O
are O
indexed O
for O
query O
processing O
and O
ranking O
purpose O
. O
The O
value O
of O
the O
proposed O
method O
is O
demonstrated O
by O
the O
relative O
high O
performance O
of O
our O
system O
, O
which O
received O
the O
highest O
overall O
ranking O
for O
US O
English O
speech O
data O
in O
the O
recent O
NIST O
Spoken B-KEY
Term I-KEY
Detection I-KEY
evaluation O
-LSB- O
1 O
-RSB- O
. O
Globally O
Synchronized O
Dead-Reckoning B-KEY
with O
Local B-KEY
Lag I-KEY
for O
Continuous O
Distributed O
Multiplayer B-KEY
Games I-KEY
ABSTRACT O
Dead-Reckoning B-KEY
-LRB- O
DR O
-RRB- O
is O
an O
effective O
method O
to O
maintain O
consistency B-KEY
for O
Continuous O
Distributed O
Multiplayer B-KEY
Games I-KEY
-LRB- O
CDMG O
-RRB- O
. O
Since O
DR O
can O
filter O
most O
unnecessary O
state O
updates O
and O
improve O
the O
scalability O
of O
a O
system O
, O
it O
is O
widely O
used O
in O
commercial O
CDMG O
. O
However O
, O
DR O
can O
not O
maintain O
high O
consistency B-KEY
, O
and O
this O
constrains O
its O
application O
in O
highly O
interactive O
games O
. O
With O
the O
help O
of O
global O
synchronization O
, O
DR O
can O
achieve O
higher O
consistency B-KEY
, O
but O
it O
still O
can O
not O
eliminate O
before O
inconsistency O
. O
In O
this O
paper O
, O
a O
method O
named O
Globally O
Synchronized O
DR O
with O
Local B-KEY
Lag I-KEY
-LRB- O
GS-DR-LL B-KEY
-RRB- O
, O
which O
combines O
local B-KEY
lag I-KEY
and O
Globally O
Synchronized O
DR O
-LRB- O
GS-DR O
-RRB- O
, O
is O
presented O
. O
Performance O
evaluation O
shows O
that O
GS-DR-LL B-KEY
can O
effectively O
decrease O
before O
inconsistency O
, O
and O
the O
effects O
increase O
with O
the O
lag O
. O
Feature O
Representation O
for O
Effective O
Action-Item B-KEY
Detection I-KEY
ABSTRACT O
E-mail B-KEY
users O
face O
an O
ever-growing O
challenge O
in O
managing O
their O
inboxes O
due O
to O
the O
growing O
centrality O
of O
email O
in O
the O
workplace O
for O
task O
assignment O
, O
action O
requests O
, O
and O
other O
roles O
beyond O
information O
dissemination O
. O
Whereas O
Information B-KEY
Retrieval I-KEY
and O
Machine O
Learning O
techniques O
are O
gaining O
initial O
acceptance O
in O
spam O
filtering O
and O
automated O
folder O
assignment O
, O
this O
paper O
reports O
on O
a O
new O
task O
: O
automated O
action-item B-KEY
detection I-KEY
, O
in O
order O
to O
flag O
emails O
that O
require O
responses O
, O
and O
to O
highlight O
the O
specific O
passage O
-LRB- O
s O
-RRB- O
indicating O
the O
request O
-LRB- O
s O
-RRB- O
for O
action O
. O
Unlike O
standard O
topic-driven O
text B-KEY
classification I-KEY
, O
action-item O
detection O
requires O
inferring O
the O
sender O
's O
intent O
, O
and O
as O
such O
responds O
less O
well O
to O
pure O
bag-of-words O
classification O
. O
However O
, O
using O
enriched O
feature O
sets O
, O
such O
as O
n-grams B-KEY
-LRB- O
up O
to O
n O
= O
4 O
-RRB- O
with O
chi-squared O
feature B-KEY
selection I-KEY
, O
and O
contextual O
cues O
for O
action-item O
location O
improve O
performance O
by O
up O
to O
10 O
% O
over O
unigrams O
, O
using O
in O
both O
cases O
state O
of O
the O
art O
classifiers O
such O
as O
SVMs O
with O
automated O
model O
selection O
via O
embedded O
cross-validation O
. O
Distance B-KEY
Measures I-KEY
for O
MPEG-7-based O
Retrieval O
ABSTRACT O
In O
visual B-KEY
information I-KEY
retrieval I-KEY
the O
careful O
choice O
of O
suitable O
proximity O
measures O
is O
a O
crucial O
success O
factor O
. O
The O
evaluation O
presented O
in O
this O
paper O
aims O
at O
showing O
that O
the O
distance B-KEY
measures I-KEY
suggested O
by O
the O
MPEG-7 B-KEY
group O
for O
the O
visual B-KEY
descriptors I-KEY
can O
be O
beaten O
by O
general-purpose O
measures O
. O
Eight O
visual O
MPEG-7 B-KEY
descriptors O
were O
selected O
and O
38 O
distance B-KEY
measures I-KEY
implemented O
. O
Three O
media B-KEY
collections I-KEY
were O
created O
and O
assessed O
, O
performance B-KEY
indicators I-KEY
developed O
and O
more O
than O
22500 O
tests O
performed O
. O
Additionally O
, O
a O
quantisation O
model O
was O
developed O
to O
be O
able O
to O
use O
predicate-based O
distance B-KEY
measures I-KEY
on O
continuous O
data O
as O
well O
. O
The O
evaluation O
shows O
that O
the O
distance B-KEY
measures I-KEY
recommended O
in O
the O
MPEG-7-standard O
are O
among O
the O
best O
but O
that O
other O
measures O
perform O
even O
better O
. O
An O
Architectural O
Framework O
and O
a O
Middleware O
for O
Cooperating O
Smart O
Components O
* O
U.Lisboa O
U.Ulm O
U.Lisboa O
casim@di.fc.ul.pt O
kaiser@informatik.uni- O
pjv@di.fc.ul.pt O
ulm.de O
ABSTRACT O
In O
a O
future O
networked O
physical O
world O
, O
a O
myriad O
of O
smart B-KEY
sensors I-KEY
and O
actuators O
assess O
and O
control O
aspects O
of O
their O
environments O
and O
autonomously O
act O
in O
response O
to O
it O
. O
Examples O
range O
in O
telematics O
, O
traffic O
management O
, O
team O
robotics O
or O
home O
automation O
to O
name O
a O
few O
. O
To O
a O
large O
extent O
, O
such O
systems O
operate O
proactively O
and O
independently O
of O
direct O
human O
control O
driven O
by O
the O
perception O
of O
the O
environment O
and O
the O
ability O
to O
organize O
respective O
computations O
dynamically O
. O
The O
challenging O
characteristics O
of O
these O
applications O
include O
sentience O
and O
autonomy O
of O
components O
, O
issues O
of O
responsiveness O
and O
safety O
criticality O
, O
geographical O
dispersion O
, O
mobility O
and O
evolution O
. O
A O
crucial O
design O
decision O
is O
the O
choice O
of O
the O
appropriate O
abstractions O
and O
interaction O
mechanisms O
. O
Looking O
to O
the O
basic O
building O
blocks O
of O
such O
systems O
we O
may O
find O
components O
which O
comprise O
mechanical O
components O
, O
hardware O
and O
software O
and O
a O
network O
interface O
, O
thus O
these O
components O
have O
different O
characteristics O
compared O
to O
pure O
software O
components O
. O
They O
are O
able O
to O
spontaneously O
disseminate O
information O
in O
response O
to O
events O
observed O
in O
the O
physical O
environment O
or O
to O
events O
received O
from O
other O
component O
via O
the O
network O
interface O
. O
Larger O
autonomous O
components O
may O
be O
composed O
recursively O
from O
these O
building O
blocks O
. O
The O
paper O
describes O
an O
architectural O
framework O
and O
a O
middleware O
supporting O
a O
component-based O
system O
and O
an O
integrated O
view O
on O
events-based O
communication O
comprising O
the O
real O
world O
events O
and O
the O
events O
generated O
in O
the O
system O
. O
It O
starts O
by O
an O
outline O
of O
the O
component-based O
system O
construction O
. O
The O
generic B-KEY
event I-KEY
architecture I-KEY
GEAR O
is O
introduced O
which O
describes O
the O
event-based O
interaction O
between O
the O
components O
via O
a O
generic O
event O
layer O
. O
The O
generic O
event O
layer O
hides O
the O
different O
communication O
channels O
including O
* O
This O
work O
was O
partially O
supported O
by O
the O
EC O
, O
through O
project O
IST-2000-26031 O
-LRB- O
CORTEX B-KEY
-RRB- O
, O
and O
by O
the O
FCT O
, O
through O
the O
Large-Scale O
Informatic O
Systems O
Laboratory O
-LRB- O
LaSIGE O
-RRB- O
and O
project O
POSI/1999/CHS O
/ O
33996 O
-LRB- O
DEFEATS O
-RRB- O
. O
the O
interactions O
through O
the O
environment O
. O
An O
appropriate O
middleware O
is O
presented O
which O
reflects O
these O
needs O
and O
allows O
to O
specify O
events O
which O
have O
quality O
attributes O
to O
express O
temporal B-KEY
constraints I-KEY
. O
This O
is O
complemented O
by O
the O
notion O
of O
event B-KEY
channels I-KEY
which O
are O
abstractions O
of O
the O
underlying O
network O
and O
allow O
to O
enforce O
quality O
attributes O
. O
They O
are O
established O
prior O
to O
interaction O
to O
reserve O
the O
needed O
computational O
and O
network O
resources O
for O
highly O
predictable O
event O
dissemination O
. O
Context B-KEY
Awareness I-KEY
for O
Group B-KEY
Interaction I-KEY
Support O
ABSTRACT O
In O
this O
paper O
, O
we O
present O
an O
implemented O
system O
for O
supporting O
group B-KEY
interaction I-KEY
in O
mobile O
distributed O
computing O
environments O
. O
First O
, O
an O
introduction O
to O
context O
computing O
and O
a O
motivation O
for O
using O
contextual O
information O
to O
facilitate O
group B-KEY
interaction I-KEY
is O
given O
. O
We O
then O
present O
the O
architecture O
of O
our O
system O
, O
which O
consists O
of O
two O
parts O
: O
a O
subsystem O
for O
location B-KEY
sensing I-KEY
that O
acquires O
information O
about O
the O
location O
of O
users O
as O
well O
as O
spatial O
proximities O
between O
them O
, O
and O
one O
for O
the O
actual O
context-aware O
application O
, O
which O
provides O
services O
for O
group B-KEY
interaction I-KEY
. O
Empirical B-KEY
Mechanism I-KEY
Design O
: O
Methods O
, O
with O
Application O
to O
a O
Supply-Chain O
Scenario O
ABSTRACT O
Our O
proposed O
methods O
employ O
learning O
and O
search O
techniques O
to O
estimate O
outcome B-KEY
features I-KEY
of I-KEY
interest I-KEY
as O
a O
function O
of O
mechanism O
parameter B-KEY
settings I-KEY
. O
We O
illustrate O
our O
approach O
with O
a O
design O
task O
from O
a O
supply-chain O
trading O
competition O
. O
Designers O
adopted O
several O
rule O
changes O
in O
order O
to O
deter O
particular O
procurement O
behavior O
, O
but O
the O
measures O
proved O
insufficient O
. O
Our O
empirical B-KEY
mechanism I-KEY
analysis B-KEY
models O
the O
relation O
between O
a O
key O
design O
parameter O
and O
outcomes O
, O
confirming O
the O
observed B-KEY
behavior I-KEY
and O
indicating O
that O
no O
reasonable O
parameter B-KEY
settings I-KEY
would O
have O
been O
likely O
to O
achieve O
the O
desired O
effect O
. O
More O
generally O
, O
we O
show O
that O
under O
certain O
conditions O
, O
the O
estimator O
of O
optimal O
mechanism O
parameter B-KEY
setting I-KEY
based O
on O
empirical O
data O
is O
consistent O
. O
Scouts B-KEY
, O
Promoters B-KEY
, O
and O
Connectors B-KEY
: O
The O
Roles O
of O
Ratings B-KEY
in O
Nearest B-KEY
Neighbor I-KEY
Collaborative B-KEY
Filtering I-KEY
ABSTRACT O
Recommender B-KEY
systems O
aggregate O
individual O
user O
ratings O
into O
predictions O
of O
products O
or O
services O
that O
might O
interest O
visitors O
. O
The O
quality O
of O
this O
aggregation B-KEY
process I-KEY
crucially O
affects O
the O
user O
experience O
and O
hence O
the O
effectiveness O
of O
recommenders B-KEY
in O
e-commerce O
. O
We O
present O
a O
novel O
study O
that O
disaggregates O
global O
recommender B-KEY
performance O
metrics O
into O
contributions O
made O
by O
each O
individual O
rating B-KEY
, O
allowing O
us O
to O
characterize O
the O
many O
roles O
played O
by O
ratings B-KEY
in O
nearestneighbor O
collaborative B-KEY
filtering I-KEY
. O
In O
particular O
, O
we O
formulate O
three O
roles O
-- O
scouts B-KEY
, O
promoters B-KEY
, O
and O
connectors B-KEY
-- O
that O
capture O
how O
users O
receive O
recommendations B-KEY
, O
how O
items O
get O
recommended B-KEY
, O
and O
how O
ratings B-KEY
of O
these O
two O
types O
are O
themselves O
connected O
-LRB- O
resp O
. O
-RRB- O
. O
These O
roles O
find O
direct O
uses O
in O
improving O
recommendations B-KEY
for O
users O
, O
in O
better O
targeting O
of O
items O
and O
, O
most O
importantly O
, O
in O
helping O
monitor O
the O
health O
of O
the O
system O
as O
a O
whole O
. O
For O
instance O
, O
they O
can O
be O
used O
to O
track O
the O
evolution O
of O
neighborhoods B-KEY
, O
to O
identify O
rating B-KEY
subspaces O
that O
do O
not O
contribute O
-LRB- O
or O
contribute O
negatively O
-RRB- O
to O
system O
performance O
, O
to O
enumerate O
users O
who O
are O
in O
danger O
of O
leaving O
, O
and O
to O
assess O
the O
susceptibility O
of O
the O
system O
to O
attacks O
such O
as O
shilling O
. O
We O
argue O
that O
the O
three O
rating B-KEY
roles O
presented O
here O
provide O
broad O
primitives O
to O
manage O
a O
recommender B-KEY
system O
and O
its O
community O
. O
Mechanism B-KEY
Design I-KEY
for O
Online O
Real-Time O
Scheduling B-KEY
ABSTRACT O
For O
the O
problem O
of O
online O
real-time O
scheduling B-KEY
of O
jobs O
on O
a O
single O
processor O
, O
previous O
work O
presents O
matching O
upper O
and O
lower O
bounds O
on O
the O
competitive B-KEY
ratio I-KEY
that O
can O
be O
achieved O
by O
a O
deterministic B-KEY
algorithm I-KEY
. O
However O
, O
these O
results O
only O
apply O
to O
the O
non-strategic B-KEY
setting I-KEY
in O
which O
the O
jobs O
are O
released O
directly O
to O
the O
algorithm O
. O
Motivated O
by O
emerging O
areas O
such O
as O
grid O
computing O
, O
we O
instead O
consider O
this O
problem O
in O
an O
economic O
setting O
, O
in O
which O
each O
job O
is O
released O
to O
a O
separate O
, O
self-interested O
agent O
. O
The O
agent O
can O
then O
delay O
releasing O
the O
job O
to O
the O
algorithm O
, O
inflate O
its O
length O
, O
and O
declare O
an O
arbitrary O
value O
and O
deadline B-KEY
for O
the O
job O
, O
while O
the O
center O
determines O
not O
only O
the O
schedule B-KEY
, O
but O
the O
payment O
of O
each O
agent O
. O
For O
the O
resulting O
mechanism B-KEY
design I-KEY
problem O
-LRB- O
in O
which O
we O
also O
slightly O
strengthen O
an O
assumption O
from O
the O
non-strategic B-KEY
setting I-KEY
-RRB- O
, O
we O
present O
a O
mechanism O
that O
addresses O
each O
incentive O
issue O
, O
while O
only O
increasing O
the O
competitive B-KEY
ratio I-KEY
by O
one O
. O
We O
then O
show O
a O
matching O
lower O
bound O
for O
deterministic B-KEY
mechanisms I-KEY
that O
never O
pay O
the O
agents O
. O
Context O
Sensitive O
Stemming B-KEY
for O
Web B-KEY
Search I-KEY
ABSTRACT O
Traditionally O
, O
stemming B-KEY
has O
been O
applied O
to O
Information O
Retrieval O
tasks O
by O
transforming O
words O
in O
documents O
to O
the O
their O
root O
form O
before O
indexing O
, O
and O
applying O
a O
similar O
transformation O
to O
query O
terms O
. O
Although O
it O
increases O
recall O
, O
this O
naive O
strategy O
does O
not O
work O
well O
for O
Web B-KEY
Search I-KEY
since O
it O
lowers O
precision O
and O
requires O
a O
significant O
amount O
of O
additional O
computation O
. O
In O
this O
paper O
, O
we O
propose O
a O
context O
sensitive O
stemming B-KEY
method O
that O
addresses O
these O
two O
issues O
. O
Two O
unique O
properties O
make O
our O
approach O
feasible O
for O
Web B-KEY
Search I-KEY
. O
First O
, O
based O
on O
statistical O
language B-KEY
modeling I-KEY
, O
we O
perform O
context O
sensitive O
analysis O
on O
the O
query O
side O
. O
We O
accurately O
predict O
which O
of O
its O
morphological O
variants O
is O
useful O
to O
expand O
a O
query O
term O
with O
before O
submitting O
the O
query O
to O
the O
search O
engine O
. O
This O
dramatically O
reduces O
the O
number O
of O
bad O
expansions O
, O
which O
in O
turn O
reduces O
the O
cost O
of O
additional O
computation O
and O
improves O
the O
precision O
at O
the O
same O
time O
. O
Second O
, O
our O
approach O
performs O
a O
context B-KEY
sensitive I-KEY
document I-KEY
matching I-KEY
for O
those O
expanded O
variants O
. O
This O
conservative O
strategy O
serves O
as O
a O
safeguard O
against O
spurious O
stemming B-KEY
, O
and O
it O
turns O
out O
to O
be O
very O
important O
for O
improving O
precision O
. O
Using O
word O
pluralization O
handling O
as O
an O
example O
of O
our O
stemming B-KEY
approach O
, O
our O
experiments O
on O
a O
major O
Web B-KEY
search I-KEY
engine O
show O
that O
stemming B-KEY
only O
29 O
% O
of O
the O
query O
traffic O
, O
we O
can O
improve O
relevance O
as O
measured O
by O
average O
Discounted O
Cumulative O
Gain O
-LRB- O
DCG5 O
-RRB- O
by O
6.1 O
% O
on O
these O
queries O
and O
1.8 O
% O
over O
all O
query O
traffic O
. O
Self-interested O
Automated B-KEY
Mechanism I-KEY
Design I-KEY
and O
Implications O
for O
Optimal O
Combinatorial O
Auctions O
∗ O
ABSTRACT O
Often O
, O
an O
outcome O
must O
be O
chosen O
on O
the O
basis O
of O
the O
preferences O
reported O
by O
a O
group O
of O
agents O
. O
The O
key O
difficulty O
is O
that O
the O
agents O
may O
report O
their O
preferences O
insincerely O
to O
make O
the O
chosen O
outcome O
more O
favorable O
to O
themselves O
. O
Mechanism B-KEY
design I-KEY
is O
the O
art O
of O
designing O
the O
rules O
of O
the O
game O
so O
that O
the O
agents O
are O
motivated O
to O
report O
their O
preferences O
truthfully O
, O
and O
a O
desirable B-KEY
outcome I-KEY
is O
chosen O
. O
In O
a O
recently O
proposed O
approach O
-- O
called O
automated B-KEY
mechanism I-KEY
design I-KEY
-- O
a O
mechanism O
is O
computed O
for O
the O
preference O
aggregation O
setting O
at O
hand O
. O
This O
has O
several O
advantages O
, O
but O
the O
downside O
is O
that O
the O
mechanism B-KEY
design I-KEY
optimization O
problem O
needs O
to O
be O
solved O
anew O
each O
time O
. O
Unlike O
the O
earlier O
work O
on O
automated B-KEY
mechanism I-KEY
design I-KEY
that O
studied O
a O
benevolent O
designer O
, O
in O
this O
paper O
we O
study O
automated O
mechanism O
design O
problems O
where O
the O
designer O
is O
self-interested O
. O
In O
this O
case O
, O
the O
center O
cares O
only O
about O
which O
outcome O
is O
chosen O
and O
what O
payments O
are O
made O
to O
it O
. O
The O
reason O
that O
the O
agents O
' O
preferences O
are O
relevant O
is O
that O
the O
center O
is O
constrained O
to O
making O
each O
agent O
at O
least O
as O
well O
off O
as O
the O
agent O
would O
have O
been O
had O
it O
not O
participated O
in O
the O
mechanism O
. O
In O
this O
setting O
, O
we O
show O
that O
designing O
optimal O
deterministic O
mechanisms O
is O
NP-complete O
in O
two O
important O
special O
cases O
: O
when O
the O
center O
is O
interested O
only O
in O
the O
payments O
made O
to O
it O
, O
and O
when O
payments O
are O
not O
possible O
and O
the O
center O
is O
interested O
only O
in O
the O
outcome O
chosen O
. O
We O
then O
show O
how O
allowing O
for O
randomization O
in O
the O
mechanism O
makes O
problems O
in O
this O
setting O
computationally O
easy O
. O
Finally O
, O
we O
show O
that O
the O
payment-maximizing O
AMD O
problem O
is O
closely O
related O
to O
an O
interesting O
variant O
of O
the O
optimal O
-LRB- O
revenuemaximizing O
-RRB- O
combinatorial B-KEY
auction I-KEY
design O
problem O
, O
where O
the O
bidders O
have O
`` O
best-only O
'' O
preferences O
. O
We O
show O
that O
here O
, O
too O
, O
designing O
an O
optimal O
deterministic O
auction O
is O
NPcomplete O
, O
but O
designing O
an O
optimal O
randomized O
auction O
is O
easy O
. O
∗ O
Supported O
by O
NSF O
under O
CAREER O
Award O
IRI-9703122 O
, O
Grant O
IIS-9800994 O
, O
ITR O
IIS-0081246 O
, O
and O
ITR O
IIS-0121678 O
. O
Searching O
for O
Joint O
Gains O
in O
Automated B-KEY
Negotiations I-KEY
Based O
on O
Multi-criteria O
Decision O
Making O
Theory O
ABSTRACT O
It O
is O
well O
established O
by O
conflict O
theorists O
and O
others O
that O
successful O
negotiation B-KEY
should O
incorporate O
`` O
creating B-KEY
value I-KEY
'' O
as O
well O
as O
`` O
claiming B-KEY
value I-KEY
. O
'' O
Joint O
improvements O
that O
bring O
benefits O
to O
all O
parties O
can O
be O
realised O
by O
-LRB- O
i O
-RRB- O
identifying O
attributes O
that O
are O
not O
of O
direct O
conflict O
between O
the O
parties O
, O
-LRB- O
ii O
-RRB- O
tradeoffs O
on O
attributes O
that O
are O
valued O
differently O
by O
different O
parties O
, O
and O
-LRB- O
iii O
-RRB- O
searching O
for O
values O
within O
attributes O
that O
could O
bring O
more O
gains O
to O
one O
party O
while O
not O
incurring O
too O
much O
loss O
on O
the O
other O
party O
. O
In O
this O
paper O
we O
propose O
an O
approach O
for O
maximising O
joint O
gains O
in O
automated B-KEY
negotiations I-KEY
by O
formulating O
the O
negotiation O
problem O
as O
a O
multi-criteria O
decision O
making O
problem O
and O
taking O
advantage O
of O
several O
optimisation O
techniques O
introduced O
by O
operations O
researchers O
and O
conflict O
theorists O
. O
We O
use O
a O
mediator B-KEY
to O
protect O
the O
negotiating B-KEY
parties O
from O
unnecessary O
disclosure O
of O
information O
to O
their O
opponent O
, O
while O
also O
allowing O
an O
objective O
calculation O
of O
maximum O
joint O
gains O
. O
We O
separate O
out O
attributes O
that O
take O
a O
finite O
set O
of O
values O
-LRB- O
simple O
attributes O
-RRB- O
from O
those O
with O
continuous O
values O
, O
and O
we O
show O
that O
for O
simple O
attributes O
, O
the O
mediator B-KEY
can O
determine O
the O
Pareto-optimal O
values O
. O
In O
addition O
we O
show O
that O
if O
none O
of O
the O
simple O
attributes O
strongly O
dominates O
the O
other O
simple O
attributes O
, O
then O
truth O
telling O
is O
an O
equilibrium O
strategy O
for O
negotiators B-KEY
during O
the O
optimisation O
of O
simple O
attributes O
. O
We O
also O
describe O
an O
approach O
for O
improving O
joint O
gains O
on O
non-simple O
attributes O
, O
by O
moving O
the O
parties O
in O
a O
series O
of O
steps O
, O
towards O
the O
Pareto-optimal O
frontier O
. O
Shooter O
Localization O
and O
Weapon B-KEY
Classification I-KEY
with O
Soldier-Wearable O
Networked O
Sensors O
ABSTRACT O
The O
paper O
presents O
a O
wireless O
sensor O
network-based O
mobile O
countersniper O
system O
. O
A O
sensor O
node O
consists O
of O
a O
helmetmounted O
microphone O
array O
, O
a O
COTS O
MICAz O
mote O
for O
internode B-KEY
communication I-KEY
and O
a O
custom O
sensorboard B-KEY
that O
implements O
the O
acoustic O
detection O
and O
Time O
of O
Arrival O
-LRB- O
ToA O
-RRB- O
estimation O
algorithms O
on O
an O
FPGA O
. O
A O
3-axis O
compass O
provides O
self B-KEY
orientation I-KEY
and O
Bluetooth O
is O
used O
for O
communication O
with O
the O
soldier O
's O
PDA O
running O
the O
data B-KEY
fusion I-KEY
and O
the O
user O
interface O
. O
The O
heterogeneous O
sensor O
fusion O
algorithm O
can O
work O
with O
data O
from O
a O
single O
sensor O
or O
it O
can O
fuse O
ToA O
or O
Angle O
of O
Arrival O
-LRB- O
AoA O
-RRB- O
observations O
of O
muzzle O
blasts O
and O
ballistic O
shockwaves O
from O
multiple O
sensors O
. O
The O
system O
estimates O
the O
trajectory B-KEY
, O
the O
range B-KEY
, O
the O
caliber B-KEY
and O
the O
weapon B-KEY
type I-KEY
. O
The O
paper O
presents O
the O
system O
design O
and O
the O
results O
from O
an O
independent O
evaluation O
at O
the O
US O
Army O
Aberdeen O
Test O
Center O
. O
The O
system O
performance O
is O
characterized O
by O
1degree O
trajectory B-KEY
precision O
and O
over O
95 O
% O
caliber O
estimation O
accuracy O
for O
all O
shots O
, O
and O
close O
to O
100 O
% O
weapon O
estimation O
accuracy O
for O
4 O
out O
of O
6 O
guns O
tested O
. O
A O
Multilateral O
Multi-issue B-KEY
Negotiation I-KEY
Protocol O
ABSTRACT O
In O
this O
paper O
, O
we O
present O
a O
new O
protocol O
to O
address O
multilateral O
multi-issue B-KEY
negotiation I-KEY
in O
a O
cooperative O
context O
. O
We O
consider O
complex O
dependencies O
between O
multiple O
issues O
by O
modelling B-KEY
the O
preferences O
of O
the O
agents O
with O
a O
multi-criteria O
decision O
aid O
tool O
, O
also O
enabling O
us O
to O
extract O
relevant O
information O
on O
a O
proposal O
assessment O
. O
This O
information O
is O
used O
in O
the O
protocol O
to O
help O
in O
accelerating O
the O
search O
for O
a O
consensus O
between O
the O
cooperative B-KEY
agents I-KEY
. O
In O
addition O
, O
the O
negotiation O
procedure O
is O
defined O
in O
a O
crisis B-KEY
management I-KEY
context O
where O
the O
common O
objective O
of O
our O
agents O
is O
also O
considered O
in O
the O
preferences O
of O
a O
mediator O
agent O
. O
Authority B-KEY
Assignment O
in O
Distributed O
Multi-Player O
Proxy-based O
Games O
ABSTRACT O
We O
present O
a O
proxy-based O
gaming O
architecture O
and O
authority B-KEY
assignment O
within O
this O
architecture O
that O
can O
lead O
to O
better O
game O
playing O
experience O
in O
Massively O
Multi-player O
Online O
games O
. O
The O
proposed O
game O
architecture O
consists O
of O
distributed O
game O
clients O
that O
connect O
to O
game O
proxies O
-LRB- O
referred O
to O
as O
`` O
communication B-KEY
proxies I-KEY
'' O
-RRB- O
which O
forward O
game O
related O
messages O
from O
the O
clients O
to O
one O
or O
more O
game O
servers O
. O
Unlike O
proxy-based O
architectures O
that O
have O
been O
proposed O
in O
the O
literature O
where O
the O
proxies O
replicate O
all O
of O
the O
game O
state O
, O
the O
communication B-KEY
proxies I-KEY
in O
the O
proposed O
architecture O
support O
clients O
that O
are O
in O
proximity O
to O
it O
in O
the O
physical O
network O
and O
maintain O
information O
about O
selected O
portions O
of O
the O
game O
space O
that O
are O
relevant O
only O
to O
the O
clients O
that O
they O
support O
. O
Using O
this O
architecture O
, O
we O
propose O
an O
authority B-KEY
assignment O
mechanism O
that O
divides O
the O
authority O
for O
deciding O
the O
outcome O
of O
different O
actions/events O
that O
occur O
within O
the O
game O
between O
client O
and O
servers O
on O
a O
per O
action/event O
basis O
. O
We O
show O
that O
such O
division O
of O
authority B-KEY
leads O
to O
a O
smoother O
game O
playing O
experience O
by O
implementing O
this O
mechanism O
in O
a O
massively O
multi-player O
online O
game O
called O
RPGQuest O
. O
In O
addition O
, O
we O
argue O
that O
cheat O
detection O
techniques O
can O
be O
easily O
implemented O
at O
the O
communication B-KEY
proxies I-KEY
if O
they O
are O
made O
aware O
of O
the O
game-play O
mechanics O
. O
An O
Evaluation O
of O
Availability B-KEY
Latency I-KEY
in O
Carrier-based O
Vehicular O
Ad-Hoc O
Networks O
Shahram O
ABSTRACT O
On-demand O
delivery O
of O
audio B-KEY
and I-KEY
video I-KEY
clips I-KEY
in O
peer-to-peer O
vehicular O
ad-hoc O
networks O
is O
an O
emerging O
area O
of O
research O
. O
Our O
target O
environment O
uses O
data B-KEY
carriers I-KEY
, O
termed B-KEY
zebroids I-KEY
, O
where O
a O
mobile O
device O
carries O
a O
data O
item O
on O
behalf O
of O
a O
server O
to O
a O
client O
thereby O
minimizing O
its O
availability O
latency O
. O
In O
this O
study O
, O
we O
quantify O
the O
variation O
in O
availability B-KEY
latency I-KEY
with O
zebroids O
as O
a O
function O
of O
a O
rich O
set O
of O
parameters O
such O
as O
car O
density O
, O
storage O
per O
device O
, O
repository O
size O
, O
and O
replacement O
policies O
employed O
by O
zebroids O
. O
Using O
analysis O
and O
extensive O
simulations O
, O
we O
gain O
novel O
insights O
into O
the O
design O
of O
carrier-based O
systems O
. O
Significant O
improvements O
in O
latency B-KEY
can O
be O
obtained O
with O
zebroids B-KEY
at O
the O
cost O
of O
a O
minimal O
overhead O
. O
These O
improvements O
occur O
even O
in O
scenarios O
with O
lower O
accuracy O
in O
the O
predictions O
of O
the O
car O
routes O
. O
Two O
particularly O
surprising O
findings O
are O
: O
-LRB- O
1 O
-RRB- O
a O
naive B-KEY
random I-KEY
replacement I-KEY
policy I-KEY
employed O
by O
the O
zebroids O
shows O
competitive O
performance O
, O
and O
-LRB- O
2 O
-RRB- O
latency O
improvements O
obtained O
with O
a O
simplified O
instantiation O
of O
zebroids O
are O
found O
to O
be O
robust O
to O
changes O
in O
the O
popularity O
distribution O
of O
the O
data O
items O
. O
Categories O
and O
Subject O
Descriptors O
: O
C. O
2.4 O
-LSB- O
Distributed O
Systems O
-RSB- O
: O
Client/Server O
From O
Optimal O
Limited O
To O
Unlimited B-KEY
Supply I-KEY
Auctions B-KEY
ABSTRACT O
We O
investigate O
the O
class O
of O
single-round O
, O
sealed-bid O
auctions B-KEY
for O
a O
set O
of O
identical O
items O
to O
bidders O
who O
each O
desire O
one O
unit O
. O
We O
adopt O
the O
worst-case O
competitive O
framework O
defined O
by O
-LSB- O
9 O
, O
5 O
-RSB- O
that O
compares O
the O
profit O
of O
an O
auction B-KEY
to O
that O
of O
an O
optimal O
single-price O
sale O
of O
least O
two O
items O
. O
In O
this O
paper O
, O
we O
first O
derive O
an O
optimal O
auction B-KEY
for O
three O
items O
, O
answering O
an O
open O
question O
from O
-LSB- O
8 O
-RSB- O
. O
Second O
, O
we O
show O
that O
the O
form O
of O
this O
auction B-KEY
is O
independent O
of O
the O
competitive O
framework O
used O
. O
Third O
, O
we O
propose O
a O
schema O
for O
converting O
a O
given O
limited-supply O
auction B-KEY
into O
an O
unlimited B-KEY
supply I-KEY
auction B-KEY
. O
Applying O
this O
technique O
to O
our O
optimal O
auction B-KEY
for O
three O
items O
, O
we O
achieve O
an O
auction B-KEY
with O
a O
competitive O
ratio B-KEY
of O
3.25 O
, O
which O
improves O
upon O
the O
previously O
best-known O
competitive O
ratio B-KEY
of O
3.39 O
from O
-LSB- O
7 O
-RSB- O
. O
Finally O
, O
we O
generalize O
a O
result O
from O
-LSB- O
8 O
-RSB- O
and O
extend O
our O
understanding O
of O
the O
nature O
of O
the O
optimal O
competitive O
auction B-KEY
by O
showing O
that O
the O
optimal O
competitive O
auction B-KEY
occasionally O
offers O
prices O
that O
are O
higher O
than O
all O
bid O
values O
. O
A O
Holistic O
Approach O
to O
High-Performance O
Computing O
: O
Xgrid B-KEY
Experience O
ABSTRACT O
The O
Ringling O
School O
of O
Art O
and O
Design B-KEY
is O
a O
fully O
accredited O
fouryear O
college O
of O
visual B-KEY
arts I-KEY
and O
design B-KEY
. O
With O
a O
student O
to O
computer O
ratio O
of O
better O
than O
2-to-1 O
, O
the O
Ringling O
School O
has O
achieved O
national O
recognition O
for O
its O
large-scale O
integration O
of O
technology O
into O
collegiate O
visual B-KEY
art I-KEY
and O
design B-KEY
education O
. O
We O
have O
found O
that O
Mac B-KEY
OS I-KEY
X I-KEY
is O
the O
best O
operating B-KEY
system I-KEY
to O
train O
future O
artists O
and O
designers B-KEY
. O
Moreover O
, O
we O
can O
now O
buy O
Macs O
to O
run O
high-end B-KEY
graphics I-KEY
, O
nonlinear B-KEY
video I-KEY
editing I-KEY
, O
animation B-KEY
, O
multimedia B-KEY
, O
web B-KEY
production I-KEY
, O
and O
digital B-KEY
video I-KEY
applications I-KEY
rather O
than O
expensive O
UNIX O
workstations O
. O
As O
visual O
artists O
cross O
from O
paint O
on O
canvas O
to O
creating O
in O
the O
digital O
realm O
, O
the O
demand O
for O
a O
highperformance B-KEY
computing I-KEY
environment O
grows O
. O
In O
our O
public O
computer O
laboratories O
, O
students O
use O
the O
computers O
most O
often O
during O
the O
workday O
; O
at O
night O
and O
on O
weekends O
the O
computers O
see O
only O
light O
use O
. O
In O
order O
to O
harness O
the O
lost O
processing O
time O
for O
tasks O
such O
as O
video O
rendering B-KEY
, O
we O
are O
testing O
Xgrid B-KEY
, O
a O
suite O
of O
Mac B-KEY
OS I-KEY
X I-KEY
applications O
recently O
developed O
by O
Apple O
for O
parallel O
and O
distributed O
high-performance O
computing O
. O
As O
with O
any O
new O
technology O
deployment O
, O
IT O
managers O
need O
to O
consider O
a O
number O
of O
factors O
as O
they O
assess O
, O
plan O
, O
and O
implement O
Xgrid B-KEY
. O
Therefore O
, O
we O
would O
like O
to O
share O
valuable O
information O
we O
learned O
from O
our O
implementation O
of O
an O
Xgrid B-KEY
environment O
with O
our O
colleagues O
. O
In O
our O
report O
, O
we O
will O
address O
issues O
such O
as O
assessing O
the O
needs O
for O
grid B-KEY
computing I-KEY
, O
potential O
applications O
, O
management O
tools O
, O
security O
, O
authentication O
, O
integration O
into O
existing O
infrastructure O
, O
application O
support O
, O
user O
training O
, O
and O
user O
support O
. O
Furthermore O
, O
we O
will O
discuss O
the O
issues O
that O
arose O
and O
the O
lessons O
learned O
during O
and O
after O
the O
implementation O
process O
. O
A O
Q-decomposition B-KEY
and O
Bounded O
RTDP O
Approach O
to O
Resource B-KEY
Allocation I-KEY
ABSTRACT O
This O
paper O
contributes O
to O
solve O
effectively O
stochastic O
resource B-KEY
allocation I-KEY
problems O
known O
to O
be O
NP-Complete O
. O
To O
address O
this O
complex O
resource B-KEY
management I-KEY
problem O
, O
a O
Qdecomposition O
approach O
is O
proposed O
when O
the O
resources O
which O
are O
already O
shared O
among O
the O
agents O
, O
but O
the O
actions O
made O
by O
an O
agent O
may O
influence O
the O
reward O
obtained O
by O
at O
least O
another O
agent O
. O
The O
Q-decomposition B-KEY
allows O
to O
coordinate O
these O
reward B-KEY
separated I-KEY
agents I-KEY
and O
thus O
permits O
to O
reduce O
the O
set O
of O
states O
and O
actions O
to O
consider O
. O
On O
the O
other O
hand O
, O
when O
the O
resources O
are O
available O
to O
all O
agents O
, O
no O
Qdecomposition O
is O
possible O
and O
we O
use O
heuristic B-KEY
search I-KEY
. O
In O
particular O
, O
the O
bounded O
Real-time O
Dynamic O
Programming O
-LRB- O
bounded O
RTDP O
-RRB- O
is O
used O
. O
Bounded O
RTDP O
concentrates O
the O
planning O
on O
significant O
states O
only O
and O
prunes O
the O
action O
space O
. O
The O
pruning O
is O
accomplished O
by O
proposing O
tight O
upper O
and O
lower O
bounds O
on O
the O
value O
function O
. O
Beyond O
PageRank B-KEY
: O
Machine B-KEY
Learning I-KEY
for O
Static B-KEY
Ranking I-KEY
ABSTRACT O
Since O
the O
publication O
of O
Brin O
and O
Page O
's O
paper O
on O
PageRank B-KEY
, O
many O
in O
the O
Web O
community O
have O
depended O
on O
PageRank B-KEY
for O
the O
static O
-LRB- O
query-independent O
-RRB- O
ordering O
of O
Web O
pages O
. O
We O
show O
that O
we O
can O
significantly O
outperform O
PageRank B-KEY
using O
features O
that O
are O
independent O
of O
the O
link O
structure O
of O
the O
Web O
. O
We O
gain O
a O
further O
boost O
in O
accuracy O
by O
using O
data O
on O
the O
frequency O
at O
which O
users O
visit O
Web O
pages O
. O
We O
use O
RankNet B-KEY
, O
a O
ranking O
machine B-KEY
learning I-KEY
algorithm O
, O
to O
combine O
these O
and O
other O
static O
features O
based O
on O
anchor O
text O
and O
domain O
characteristics O
. O
The O
resulting O
model O
achieves O
a O
static B-KEY
ranking I-KEY
pairwise O
accuracy O
of O
67.3 O
% O
-LRB- O
vs. O
56.7 O
% O
for O
PageRank B-KEY
or O
50 O
% O
for O
random O
-RRB- O
. O
Impedance O
Coupling O
in O
Content-targeted B-KEY
Advertising I-KEY
ABSTRACT O
The O
current O
boom O
of O
the O
Web B-KEY
is O
associated O
with O
the O
revenues O
originated O
from O
on-line O
advertising B-KEY
. O
While O
search-based O
advertising B-KEY
is O
dominant O
, O
the O
association O
of O
ads O
with O
a O
Web B-KEY
page O
-LRB- O
during O
user O
navigation O
-RRB- O
is O
becoming O
increasingly O
important O
. O
In O
this O
work O
, O
we O
study O
the O
problem O
of O
associating O
ads O
with O
a O
Web B-KEY
page O
, O
referred O
to O
as O
content-targeted B-KEY
advertising I-KEY
, O
from O
a O
computer O
science O
perspective O
. O
We O
assume O
that O
we O
have O
access O
to O
the O
text O
of O
the O
Web B-KEY
page O
, O
the O
keywords O
declared O
by O
an O
advertiser B-KEY
, O
and O
a O
text O
associated O
with O
the O
advertiser B-KEY
's O
business O
. O
Using O
no O
other O
information O
and O
operating O
in O
fully O
automatic O
fashion O
, O
we O
propose O
ten O
strategies O
for O
solving O
the O
problem O
and O
evaluate O
their O
effectiveness O
. O
Our O
methods O
indicate O
that O
a O
matching B-KEY
strategy I-KEY
that O
takes O
into O
account O
the O
semantics O
of O
the O
problem O
-LRB- O
referred O
to O
as O
AAK O
for O
`` O
ads B-KEY
and I-KEY
keywords I-KEY
'' O
-RRB- O
can O
yield O
gains O
in O
average O
precision O
figures O
of O
60 O
% O
compared O
to O
a O
trivial O
vector-based O
strategy O
. O
Further O
, O
a O
more O
sophisticated O
impedance B-KEY
coupling I-KEY
strategy I-KEY
, O
which O
expands O
the O
text O
of O
the O
Web B-KEY
page O
to O
reduce O
vocabulary O
impedance O
with O
regard O
to O
an O
advertisement B-KEY
, O
can O
yield O
extra O
gains O
in O
average O
precision O
of O
50 O
% O
. O
These O
are O
first O
results O
. O
They O
suggest O
that O
great O
accuracy O
in O
content-targeted B-KEY
advertising I-KEY
can O
be O
attained O
with O
appropriate O
algorithms O
. O
SIGIR O
2007 O
Proceedings O
Session O
20 O
: O
Link O
Analysis O
HITS B-KEY
on O
the O
Web O
: O
How O
does O
it O
Compare O
? O
* O
ABSTRACT O
This O
paper O
describes O
a O
large-scale O
evaluation O
of O
the O
effectiveness O
of O
HITS B-KEY
in O
comparison O
with O
other O
link-based O
ranking B-KEY
algorithms O
, O
when O
used O
in O
combination O
with O
a O
state-ofthe-art O
text O
retrieval O
algorithm O
exploiting O
anchor O
text O
. O
We O
quantified O
their O
effectiveness O
using O
three O
common O
performance O
measures O
: O
the O
mean B-KEY
reciprocal I-KEY
rank I-KEY
, O
the O
mean O
average O
precision O
, O
and O
the O
normalized O
discounted O
cumulative O
gain O
measurements O
. O
The O
evaluation O
is O
based O
on O
two O
large O
data O
sets O
: O
a O
breadth-first B-KEY
search I-KEY
crawl I-KEY
of O
463 O
million O
web O
pages O
containing O
17.6 O
billion O
hyperlinks O
and O
referencing O
2.9 O
billion O
distinct O
URLs O
; O
and O
a O
set O
of O
28,043 O
queries O
sampled O
from O
a O
query O
log O
, O
each O
query O
having O
on O
average O
2,383 O
results O
, O
about O
17 O
of O
which O
were O
labeled O
by O
judges O
. O
We O
found O
that O
HITS B-KEY
outperforms O
PageRank B-KEY
, O
but O
is O
about O
as O
effective O
as O
web-page O
in-degree O
. O
The O
same O
holds O
true O
when O
any O
of O
the O
link-based O
features O
are O
combined O
with O
the O
text O
retrieval O
algorithm O
. O
Finally O
, O
we O
studied O
the O
relationship O
between O
query B-KEY
specificity I-KEY
and O
the O
effectiveness O
of O
selected O
features O
, O
and O
found O
that O
link-based O
features O
perform O
better O
for O
general O
queries O
, O
whereas O
BM25F B-KEY
performs O
better O
for O
specific O
queries O
. O
An O
Analysis O
of O
Alternative B-KEY
Slot I-KEY
Auction I-KEY
Designs I-KEY
for O
Sponsored B-KEY
Search I-KEY
ABSTRACT O
Billions O
of O
dollars O
are O
spent O
each O
year O
on O
sponsored B-KEY
search I-KEY
, O
a O
form O
of O
advertising O
where O
merchants O
pay O
for O
placement O
alongside O
web O
search O
results O
. O
Slots O
for O
ad B-KEY
listings I-KEY
are O
allocated O
via O
an O
auction-style O
mechanism O
where O
the O
higher O
a O
merchant O
bids O
, O
the O
more O
likely O
his O
ad O
is O
to O
appear O
above O
other O
ads O
on O
the O
page O
. O
In O
this O
paper O
we O
analyze O
the O
incentive O
, O
efficiency O
, O
and O
revenue O
properties O
of O
two O
slot O
auction O
designs O
: O
`` O
rank B-KEY
by I-KEY
bid I-KEY
'' O
-LRB- O
RBB O
-RRB- O
and O
`` O
rank B-KEY
by I-KEY
revenue I-KEY
'' O
-LRB- O
RBR O
-RRB- O
, O
which O
correspond O
to O
stylized O
versions O
of O
the O
mechanisms O
currently O
used O
by O
Yahoo! O
and O
Google O
, O
respectively O
. O
We O
also O
consider O
first O
- O
and O
second-price O
payment O
rules O
together O
with O
each O
of O
these O
allocation O
rules O
, O
as O
both O
have O
been O
used O
historically O
. O
We O
consider O
both O
the O
`` O
short-run O
'' O
incomplete B-KEY
information I-KEY
setting O
and O
the O
`` O
long-run O
'' O
complete O
information O
setting O
. O
With O
incomplete B-KEY
information I-KEY
, O
neither O
RBB O
nor O
RBR O
are O
truthful O
with O
either O
first O
or O
second B-KEY
pricing I-KEY
. O
We O
find O
that O
the O
informational O
requirements O
of O
RBB O
are O
much O
weaker O
than O
those O
of O
RBR O
, O
but O
that O
RBR O
is O
efficient O
whereas O
RBB O
is O
not O
. O
We O
also O
show O
that O
no O
revenue O
ranking O
of O
RBB O
and O
RBR O
is O
possible O
given O
an O
arbitrary O
distribution O
over O
bidder O
values O
and O
relevance O
. O
With O
complete O
information O
, O
we O
find O
that O
no O
equilibrium O
exists O
with O
first O
pricing O
using O
either O
RBB O
or O
RBR O
. O
We O
show O
that O
there O
typically O
exists O
a O
multitude O
of O
equilibria O
with O
second B-KEY
pricing I-KEY
, O
and O
we O
bound O
the O
divergence O
of O
-LRB- O
economic O
-RRB- O
value O
in O
such O
equilibria O
from O
the O
value O
obtained O
assuming O
all O
merchants O
bid O
truthfully O
. O
Broad B-KEY
Expertise I-KEY
Retrieval I-KEY
in O
Sparse B-KEY
Data I-KEY
Environments I-KEY
ABSTRACT O
Expertise O
retrieval O
has O
been O
largely O
unexplored O
on O
data O
other O
than O
the O
W3C O
collection O
. O
At O
the O
same O
time O
, O
many O
intranets O
of O
universities O
and O
other O
knowledge-intensive O
organisations O
offer O
examples O
of O
relatively O
small O
but O
clean O
multilingual O
expertise O
data O
, O
covering O
broad O
ranges O
of O
expertise O
areas O
. O
We O
first O
present O
two O
main O
expertise O
retrieval O
tasks O
, O
along O
with O
a O
set O
of O
baseline O
approaches O
based O
on O
generative B-KEY
language I-KEY
modeling I-KEY
, O
aimed O
at O
finding O
expertise O
relations O
between O
topics O
and O
people O
. O
For O
our O
experimental O
evaluation O
, O
we O
introduce O
-LRB- O
and O
release O
-RRB- O
a O
new O
test O
set O
based O
on O
a O
crawl O
of O
a O
university O
site O
. O
Using O
this O
test O
set O
, O
we O
conduct O
two O
series O
of O
experiments O
. O
The O
first O
is O
aimed O
at O
determining O
the O
effectiveness O
of O
baseline B-KEY
expertise I-KEY
retrieval I-KEY
methods I-KEY
applied O
to O
the O
new O
test O
set O
. O
The O
second O
is O
aimed O
at O
assessing O
refined O
models O
that O
exploit O
characteristic O
features O
of O
the O
new O
test O
set O
, O
such O
as O
the O
organizational B-KEY
structure I-KEY
of O
the O
university O
, O
and O
the O
hierarchical O
structure O
of O
the O
topics O
in O
the O
test O
set O
. O
Expertise O
retrieval O
models O
are O
shown O
to O
be O
robust O
with O
respect O
to O
environments O
smaller O
than O
the O
W3C O
collection O
, O
and O
current O
techniques O
appear O
to O
be O
generalizable O
to O
other O
settings O
. O
Evaluating O
Adaptive B-KEY
Resource I-KEY
Management I-KEY
for O
Distributed O
Real-Time O
Embedded O
Systems O
ABSTRACT O
A O
challenging O
problem O
faced O
by O
researchers O
and O
developers O
of O
distributed O
real-time O
and O
embedded O
-LRB- O
DRE O
-RRB- O
systems O
is O
devising O
and O
implementing O
effective O
adaptive B-KEY
resource I-KEY
management I-KEY
strategies O
that O
can O
meet O
end-to-end O
quality B-KEY
of I-KEY
service I-KEY
-LRB- O
QoS O
-RRB- O
requirements O
in O
varying O
operational O
conditions O
. O
This O
paper O
presents O
two O
contributions O
to O
research O
in O
adaptive B-KEY
resource I-KEY
management I-KEY
for O
DRE O
systems O
. O
First O
, O
we O
describe O
the O
structure O
and O
functionality O
of O
the O
Hybrid B-KEY
Adaptive I-KEY
Resourcemanagement I-KEY
Middleware I-KEY
-LRB- O
HyARM O
-RRB- O
, O
which O
provides O
adaptive B-KEY
resource I-KEY
management I-KEY
using O
hybrid B-KEY
control I-KEY
techniques I-KEY
for O
adapting O
to O
workload O
fluctuations O
and O
resource O
availability O
. O
Second O
, O
we O
evaluate O
the O
adaptive O
behavior O
of O
HyARM O
via O
experiments O
on O
a O
DRE O
multimedia O
system O
that O
distributes O
video O
in O
real-time O
. O
Our O
results O
indicate O
that O
HyARM O
yields O
predictable O
, O
stable O
, O
and O
high O
system O
performance O
, O
even O
in O
the O
face O
of O
fluctuating O
workload O
and O
resource O
availability O
. O
Towards O
Truthful B-KEY
Mechanisms I-KEY
for O
Binary B-KEY
Demand I-KEY
Games I-KEY
: O
A O
General O
Framework O
ABSTRACT O
The O
family O
of O
Vickrey-Clarke-Groves O
-LRB- O
VCG O
-RRB- O
mechanisms O
is O
arguably O
the O
most O
celebrated O
achievement O
in O
truthful B-KEY
mechanism I-KEY
design O
. O
However O
, O
VCG O
mechanisms O
have O
their O
limitations O
. O
They O
only O
apply O
to O
optimization O
problems O
with O
a O
utilitarian O
-LRB- O
or O
affine O
-RRB- O
objective B-KEY
function I-KEY
, O
and O
their O
output O
should O
optimize O
the O
objective B-KEY
function I-KEY
. O
For O
many O
optimization O
problems O
, O
finding O
the O
optimal O
output O
is O
computationally O
intractable O
. O
If O
we O
apply O
VCG O
mechanisms O
to O
polynomial-time O
algorithms O
that O
approximate O
the O
optimal O
solution O
, O
the O
resulting O
mechanisms O
may O
no O
longer O
be O
truthful O
. O
In O
light O
of O
these O
limitations O
, O
it O
is O
useful O
to O
study O
whether O
we O
can O
design O
a O
truthful O
non-VCG O
payment O
scheme O
that O
is O
computationally O
tractable O
for O
a O
given O
allocation O
rule O
O O
. O
In O
this O
paper O
, O
we O
focus O
our O
attention O
on O
binary B-KEY
demand I-KEY
games I-KEY
in O
which O
the O
agents O
' O
only O
available O
actions O
are O
to O
take O
part O
in O
the O
a O
game O
or O
not O
to O
. O
For O
these O
problems O
, O
we O
prove O
that O
a O
truthful B-KEY
mechanism I-KEY
M O
= O
-LRB- O
O O
, O
P O
-RRB- O
exists O
with O
a O
proper O
payment O
method O
P O
iff O
the O
allocation O
rule O
O O
satisfies O
a O
certain O
monotonicity B-KEY
property I-KEY
. O
We O
provide O
a O
general O
framework O
to O
design O
such O
P O
. O
We O
further O
propose O
several O
general O
composition-based O
techniques O
to O
compute O
P O
efficiently O
for O
various O
types O
of O
output O
. O
In O
particular O
, O
we O
show O
how O
P O
can O
be O
computed O
through O
`` O
or/and O
'' O
combinations B-KEY
, O
round-based O
combinations B-KEY
, O
and O
some O
more O
complex O
combinations B-KEY
of O
the O
outputs O
from O
subgames O
. O
Exchanging O
Reputation B-KEY
Values O
among O
Heterogeneous O
Agent O
Reputation O
Models O
: O
An O
Experience O
on O
ART O
Testbed O
ABSTRACT O
In O
open O
MAS O
it O
is O
often O
a O
problem O
to O
achieve O
agents O
' O
interoperability B-KEY
. O
The O
heterogeneity O
of O
its O
components O
turns O
the O
establishment O
of O
interaction O
or O
cooperation O
among O
them O
into O
a O
non O
trivial O
task O
, O
since O
agents O
may O
use O
different O
internal O
models O
and O
the O
decision O
about O
trust B-KEY
other O
agents O
is O
a O
crucial O
condition O
to O
the O
formation O
of O
agents O
' O
cooperation O
. O
In O
this O
paper O
we O
propose O
the O
use O
of O
an O
ontology B-KEY
to O
deal O
with O
this O
issue O
. O
We O
experiment O
this O
idea O
by O
enhancing O
the O
ART O
reputation B-KEY
model O
with O
semantic O
data O
obtained O
from O
this O
ontology O
. O
This O
data O
is O
used O
during O
interaction O
among O
heterogeneous B-KEY
agents I-KEY
when O
exchanging O
reputation B-KEY
values O
and O
may O
be O
used O
for O
agents O
that O
use O
different O
reputation O
models O
. O
Negotiation B-KEY
by O
Abduction O
and O
Relaxation B-KEY
ABSTRACT O
This O
paper O
studies O
a O
logical O
framework O
for O
automated B-KEY
negotiation I-KEY
between O
two O
agents O
. O
We O
suppose O
an O
agent O
who O
has O
a O
knowledge O
base O
represented O
by O
a O
logic B-KEY
program I-KEY
. O
Then O
, O
we O
introduce O
methods O
of O
constructing O
counter-proposals O
in O
response O
to O
proposals O
made O
by O
an O
agent O
. O
To O
this O
end O
, O
we O
combine O
the O
techniques O
of O
extended B-KEY
abduction I-KEY
in O
artificial O
intelligence O
and O
relaxation B-KEY
in O
cooperative O
query O
answering O
for O
databases O
. O
These O
techniques O
are O
respectively O
used O
for O
producing O
conditional B-KEY
proposals I-KEY
and O
neighborhood O
proposals O
in O
the O
process O
of O
negotiation B-KEY
. O
We O
provide O
a O
negotiation B-KEY
protocol O
based O
on O
the O
exchange O
of O
these O
proposals O
and O
develop O
procedures O
for O
computing O
new O
proposals O
. O
On O
the O
Computational O
Power O
of O
Iterative O
Auctions O
* O
ABSTRACT O
We O
embark O
on O
a O
systematic O
analysis O
of O
the O
power O
and O
limitations O
of O
iterative O
combinatorial B-KEY
auctions I-KEY
. O
Most O
existing O
iterative O
combinatorial B-KEY
auctions I-KEY
are O
based O
on O
repeatedly O
suggesting O
prices B-KEY
for O
bundles O
of O
items O
, O
and O
querying O
the O
bidders B-KEY
for O
their O
`` O
demand O
'' O
under O
these O
prices B-KEY
. O
We O
prove O
a O
large O
number O
of O
results O
showing O
the O
boundaries O
of O
what O
can O
be O
achieved O
by O
auctions O
of O
this O
kind O
. O
We O
first O
focus O
on O
auctions O
that O
use O
a O
polynomial O
number O
of O
demand B-KEY
queries I-KEY
, O
and O
then O
we O
analyze O
the O
power O
of O
different O
kinds O
of O
ascending-price O
auctions O
. O
Information B-KEY
Markets I-KEY
vs. O
Opinion B-KEY
Pools I-KEY
: O
An O
Empirical O
Comparison O
ABSTRACT O
In O
this O
paper O
, O
we O
examine O
the O
relative O
forecast B-KEY
accuracy O
of O
information B-KEY
markets I-KEY
versus O
expert B-KEY
aggregation I-KEY
. O
We O
leverage O
a O
unique O
data O
source O
of O
almost O
2000 O
people O
's O
subjective O
probability O
judgments O
on O
2003 O
US O
National O
Football O
League O
games O
and O
compare O
with O
the O
`` O
market B-KEY
probabilities I-KEY
'' O
given O
by O
two O
different O
information B-KEY
markets I-KEY
on O
exactly O
the O
same O
events O
. O
We O
combine O
assessments O
of O
multiple O
experts O
via O
linear O
and O
logarithmic O
aggregation O
functions O
to O
form O
pooled B-KEY
predictions I-KEY
. O
Prices B-KEY
in O
information B-KEY
markets I-KEY
are O
used O
to O
derive O
market O
predictions O
. O
Our O
results O
show O
that O
, O
at O
the O
same O
time O
point O
ahead O
of O
the O
game O
, O
information B-KEY
markets I-KEY
provide O
as O
accurate O
predictions O
as O
pooled O
expert O
assessments O
. O
In O
screening O
pooled O
expert O
predictions O
, O
we O
find O
that O
arithmetic O
average O
is O
a O
robust O
and O
efficient O
pooling O
function O
; O
weighting O
expert O
assessments O
according O
to O
their O
past O
performance O
does O
not O
improve O
accuracy O
of O
pooled B-KEY
predictions I-KEY
; O
and O
logarithmic O
aggregation O
functions O
offer O
bolder O
predictions O
than O
linear O
aggregation O
functions O
. O
The O
results O
provide O
insights O
into O
the O
predictive O
performance O
of O
information B-KEY
markets I-KEY
, O
and O
the O
relative O
merits O
of O
selecting O
among O
various O
opinion B-KEY
pooling I-KEY
methods O
. O
A O
Price-Anticipating O
Resource B-KEY
Allocation I-KEY
Mechanism O
for O
Distributed B-KEY
Shared I-KEY
Clusters I-KEY
ABSTRACT O
In O
this O
paper O
we O
formulate O
the O
fixed O
budget O
resource B-KEY
allocation I-KEY
game O
to O
understand O
the O
performance O
of O
a O
distributed O
marketbased O
resource B-KEY
allocation I-KEY
system O
. O
Multiple O
users O
decide O
how O
to O
distribute O
their O
budget O
-LRB- O
bids O
-RRB- O
among O
multiple O
machines O
according O
to O
their O
individual O
preferences O
to O
maximize O
their O
individual O
utility B-KEY
. O
We O
look O
at O
both O
the O
efficiency B-KEY
and O
the O
fairness B-KEY
of O
the O
allocation O
at O
the O
equilibrium O
, O
where O
fairness B-KEY
is O
evaluated O
through O
the O
measures O
of O
utility B-KEY
uniformity O
and O
envy-freeness O
. O
We O
show O
analytically O
and O
through O
simulations B-KEY
that O
despite O
being O
highly O
decentralized O
, O
such O
a O
system O
converges O
quickly O
to O
an O
equilibrium O
and O
unlike O
the O
social O
optimum O
that O
achieves O
high O
efficiency B-KEY
but O
poor O
fairness B-KEY
, O
the O
proposed O
allocation O
scheme O
achieves O
a O
nice O
balance O
of O
high O
degrees O
of O
efficiency B-KEY
and O
fairness B-KEY
at O
the O
equilibrium O
. O
TSAR O
: O
A O
Two O
Tier O
Sensor O
Storage O
Architecture O
Using O
Interval B-KEY
Skip I-KEY
Graphs I-KEY
* O
ABSTRACT O
Archival B-KEY
storage O
of O
sensor O
data O
is O
necessary O
for O
applications O
that O
query O
, O
mine O
, O
and O
analyze O
such O
data O
for O
interesting O
features O
and O
trends O
. O
We O
argue O
that O
existing O
storage O
systems O
are O
designed O
primarily O
for O
flat O
hierarchies O
of O
homogeneous O
sensor O
nodes O
and O
do O
not O
fully O
exploit O
the O
multi-tier O
nature O
of O
emerging O
sensor O
networks O
, O
where O
an O
application O
can O
comprise O
tens O
of O
tethered O
proxies O
, O
each O
managing O
tens O
to O
hundreds O
of O
untethered O
sensors O
. O
We O
present O
TSAR O
, O
a O
fundamentally O
different O
storage O
architecture O
that O
envisions O
separation B-KEY
of I-KEY
data I-KEY
from O
metadata O
by O
employing O
local O
archiving B-KEY
at O
the O
sensors O
and O
distributed O
indexing O
at O
the O
proxies O
. O
At O
the O
proxy O
tier O
, O
TSAR O
employs O
a O
novel O
multi-resolution O
ordered O
distributed B-KEY
index I-KEY
structure I-KEY
, O
the O
Interval B-KEY
Skip I-KEY
Graph I-KEY
, O
for O
efficiently O
supporting O
spatio-temporal O
and O
value O
queries O
. O
At O
the O
sensor O
tier O
, O
TSAR O
supports O
energy-aware O
adaptive O
summarization O
that O
can O
trade O
off O
the O
cost O
of O
transmitting O
metadata O
to O
the O
proxies O
against O
the O
overhead O
offalse O
hits O
resultingfrom O
querying O
a O
coarse-grain O
index O
. O
We O
implement O
TSAR O
in O
a O
two-tier O
sensor O
testbed O
comprising O
Stargatebased O
proxies O
and O
Mote-based O
sensors O
. O
Our O
experiments O
demonstrate O
the O
benefits O
and O
feasibility O
of O
using O
our O
energy-efficient O
storage O
architecture O
in O
multi-tier O
sensor O
networks O
. O
Marginal B-KEY
Contribution I-KEY
Nets O
: O
A O
Compact O
Representation B-KEY
Scheme O
for O
Coalitional O
Games O
* O
ABSTRACT O
We O
present O
a O
new O
approach O
to O
representing O
coalitional B-KEY
games I-KEY
based O
on O
rules O
that O
describe O
the O
marginal B-KEY
contributions I-KEY
of O
the O
agents B-KEY
. O
This O
representation B-KEY
scheme O
captures O
characteristics O
of O
the O
interactions B-KEY
among O
the O
agents B-KEY
in O
a O
natural O
and O
concise O
manner O
. O
We O
also O
develop O
efficient O
algorithms O
for O
two O
of O
the O
most O
important O
solution O
concepts O
, O
the O
Shapley O
value O
and O
the O
core B-KEY
, O
under O
this O
representation B-KEY
. O
The O
Shapley O
value O
can O
be O
computed O
in O
time O
linear O
in O
the O
size O
of O
the O
input O
. O
The O
emptiness O
of O
the O
core B-KEY
can O
be O
determined O
in O
time O
exponential O
only O
in O
the O
treewidth B-KEY
of O
a O
graphical O
interpretation O
of O
our O
representation B-KEY
. O
Demonstration O
of O
Grid-Enabled O
Ensemble B-KEY
Kalman I-KEY
Filter I-KEY
Data B-KEY
Assimilation I-KEY
Methodology I-KEY
for O
Reservoir O
Characterization O
ABSTRACT O
Ensemble B-KEY
Kalman I-KEY
filter I-KEY
data B-KEY
assimilation I-KEY
methodology I-KEY
is O
a O
popular O
approach O
for O
hydrocarbon B-KEY
reservoir I-KEY
simulations I-KEY
in O
energy B-KEY
exploration I-KEY
. O
In O
this O
approach O
, O
an O
ensemble O
of O
geological O
models O
and O
production O
data O
of O
oil O
fields O
is O
used O
to O
forecast O
the O
dynamic O
response O
of O
oil O
wells O
. O
The O
Schlumberger O
ECLIPSE O
software O
is O
used O
for O
these O
simulations O
. O
Since O
models O
in O
the O
ensemble O
do O
not O
communicate O
, O
message-passing O
implementation O
is O
a O
good O
choice O
. O
Each O
model O
checks O
out O
an O
ECLIPSE O
license O
and O
therefore O
, O
parallelizability O
of O
reservoir O
simulations O
depends O
on O
the O
number O
licenses O
available O
. O
We O
have O
Grid-enabled O
the O
ensemble B-KEY
Kalman I-KEY
filter I-KEY
data B-KEY
assimilation I-KEY
methodology I-KEY
for O
the O
TIGRE B-KEY
Grid B-KEY
computing I-KEY
environment O
. O
By O
pooling O
the O
licenses O
and O
computing O
resources O
across O
the O
collaborating O
institutions O
using O
GridWay O
metascheduler O
and O
TIGRE B-KEY
environment O
, O
the O
computational O
accuracy O
can O
be O
increased O
while O
reducing O
the O
simulation O
runtime O
. O
In O
this O
paper O
, O
we O
provide O
an O
account O
of O
our O
efforts O
in O
Gridenabling O
the O
ensemble B-KEY
Kalman I-KEY
Filter I-KEY
data B-KEY
assimilation I-KEY
methodology I-KEY
. O
Potential O
benefits O
of O
this O
approach O
, O
observations O
and O
lessons O
learned O
will O
be O
discussed O
. O
A O
Unified O
and O
General O
Framework B-KEY
for O
Argumentation-based O
Negotiation B-KEY
ABSTRACT O
This O
paper O
proposes O
a O
unified O
and O
general O
framework B-KEY
for O
argumentation-based O
negotiation B-KEY
, O
in O
which O
the O
role O
of O
argumentation B-KEY
is O
formally O
analyzed O
. O
The O
framework B-KEY
makes O
it O
possible O
to O
study O
the O
outcomes B-KEY
of O
an O
argumentation-based O
negotiation B-KEY
. O
It O
shows O
what O
an O
agreement O
is O
, O
how O
it O
is O
related O
to O
the O
theories B-KEY
of O
the O
agents B-KEY
, O
when O
it O
is O
possible O
, O
and O
how O
this O
can O
be O
attained O
by O
the O
negotiating B-KEY
agents B-KEY
in O
this O
case O
. O
It O
defines O
also O
the O
notion B-KEY
of I-KEY
concession I-KEY
, O
and O
shows O
in O
which O
situation O
an O
agent B-KEY
will O
make O
one O
, O
as O
well O
as O
how O
it O
influences O
the O
evolution O
of O
the O
dialogue O
. O
The O
Dynamics O
of O
Viral B-KEY
Marketing I-KEY
* O
ABSTRACT O
We O
present O
an O
analysis O
of O
a O
person-to-person O
recommendation B-KEY
network I-KEY
, O
consisting O
of O
4 O
million O
people O
who O
made O
16 O
million O
recommendations O
on O
half O
a O
million O
products B-KEY
. O
We O
observe O
the O
propagation O
of O
recommendations O
and O
the O
cascade O
sizes O
, O
which O
we O
explain O
by O
a O
simple O
stochastic B-KEY
model I-KEY
. O
We O
then O
establish O
how O
the O
recommendation B-KEY
network I-KEY
grows O
over O
time O
and O
how O
effective O
it O
is O
from O
the O
viewpoint O
of O
the O
sender O
and O
receiver O
of O
the O
recommendations O
. O
While O
on O
average O
recommendations O
are O
not O
very O
effective O
at O
inducing O
purchases B-KEY
and O
do O
not O
spread O
very O
far O
, O
we O
present O
a O
model O
that O
successfully O
identifies O
product B-KEY
and O
pricing B-KEY
categories I-KEY
for O
which O
viral B-KEY
marketing I-KEY
seems O
to O
be O
very O
effective O
. O
Implementing O
Commitment-Based O
Interactions O
* O
ABSTRACT O
Although O
agent B-KEY
interaction I-KEY
plays O
a O
vital O
role O
in O
MAS O
, O
and O
messagecentric B-KEY
approaches I-KEY
to O
agent B-KEY
interaction I-KEY
have O
their O
drawbacks O
, O
present O
agent-oriented O
programming O
languages O
do O
not O
provide O
support O
for O
implementing O
agent B-KEY
interaction I-KEY
that O
is O
flexible O
and O
robust O
. O
Instead O
, O
messages O
are O
provided O
as O
a O
primitive O
building O
block O
. O
In O
this O
paper O
we O
consider O
one O
approach O
for O
modelling O
agent B-KEY
interactions I-KEY
: O
the O
commitment B-KEY
machines I-KEY
framework O
. O
This O
framework O
supports O
modelling O
interactions O
at O
a O
higher O
level O
-LRB- O
using O
social B-KEY
commitments I-KEY
-RRB- O
, O
resulting O
in O
more O
flexible O
interactions O
. O
We O
investigate O
how O
commitmentbased O
interactions O
can O
be O
implemented O
in O
conventional O
agent-oriented O
programming O
languages O
. O
The O
contributions O
of O
this O
paper O
are O
: O
a O
mapping O
from O
a O
commitment B-KEY
machine I-KEY
to O
a O
collection O
of O
BDI-style O
plans O
; O
extensions O
to O
the O
semantics O
of O
BDI O
programming O
languages O
; O
and O
an O
examination O
of O
two O
issues O
that O
arise O
when O
distributing O
commitment O
machines O
-LRB- O
turn O
management O
and O
race O
conditions O
-RRB- O
and O
solutions O
to O
these O
problems O
. O
On O
Decentralized B-KEY
Incentive I-KEY
Compatible I-KEY
Mechanisms I-KEY
for O
Partially B-KEY
Informed I-KEY
Environments I-KEY
* O
ABSTRACT O
Algorithmic O
Mechanism O
Design O
focuses O
on O
Dominant B-KEY
Strategy I-KEY
Implementations I-KEY
. O
The O
main O
positive O
results O
are O
the O
celebrated O
Vickrey-Clarke-Groves O
-LRB- O
VCG O
-RRB- O
mechanisms O
and O
computationally O
efficient O
mechanisms O
for O
severely O
restricted O
players O
-LRB- O
`` O
single-parameter O
domains O
'' O
-RRB- O
. O
As O
it O
turns O
out O
, O
many O
natural O
social O
goals O
can O
not O
be O
implemented O
using O
the O
dominant O
strategy O
concept O
-LSB- O
35 O
, O
32 O
, O
22 O
, O
20 O
-RSB- O
. O
This O
suggests O
that O
the O
standard O
requirements O
must O
be O
relaxed O
in O
order O
to O
construct O
general-purpose O
mechanisms O
. O
We O
observe O
that O
in O
many O
common O
distributed B-KEY
environments I-KEY
computational B-KEY
entities I-KEY
can O
take O
advantage O
of O
the O
network O
structure O
to O
collect O
and O
distribute O
information O
. O
We O
thus O
suggest O
a O
notion O
of O
partially B-KEY
informed I-KEY
environments I-KEY
. O
Even O
if O
the O
information O
is O
recorded O
with O
some O
probability O
, O
this O
enables O
us O
to O
implement O
a O
wider O
range O
of O
social O
goals O
, O
using O
the O
concept O
of O
iterative B-KEY
elimination I-KEY
of I-KEY
weakly I-KEY
dominated I-KEY
strategies I-KEY
. O
As O
a O
result O
, O
cooperation B-KEY
is O
achieved O
independent O
of O
agents B-KEY
' O
belief O
. O
As O
a O
case O
study O
, O
we O
apply O
our O
methods O
to O
derive O
Peer-to-Peer O
network O
mechanism O
for O
file O
sharing O
. O
Consistency-preserving O
Caching O
of O
Dynamic O
Database B-KEY
Content I-KEY
* O
ABSTRACT O
With O
the O
growing O
use O
of O
dynamic O
web O
content O
generated O
from O
relational B-KEY
databases I-KEY
, O
traditional O
caching O
solutions O
for O
throughput O
and O
latency O
improvements O
are O
ineffective O
. O
We O
describe O
a O
middleware O
layer O
called O
Ganesh O
that O
reduces O
the O
volume O
of O
data O
transmitted O
without O
semantic O
interpretation O
of O
queries O
or O
results O
. O
It O
achieves O
this O
reduction O
through O
the O
use O
of O
cryptographic O
hashing O
to O
detect O
similarities O
with O
previous O
results O
. O
These O
benefits O
do O
not O
require O
any O
compromise O
of O
the O
strict O
consistency O
semantics O
provided O
by O
the O
back-end O
database O
. O
Further O
, O
Ganesh O
does O
not O
require O
modifications O
to O
applications O
, O
web O
servers O
, O
or O
database O
servers O
, O
and O
works O
with O
closed-source O
applications O
and O
databases O
. O
Using O
two O
benchmarks O
representative O
of O
dynamic O
web O
sites O
, O
measurements O
of O
our O
prototype O
show O
that O
it O
can O
increase O
end-to-end O
throughput O
by O
as O
much O
as O
twofold O
for O
non-data O
intensive O
applications O
and O
by O
as O
much O
as O
tenfold O
for O
data O
intensive O
ones O
. O
Adapting O
Asynchronous B-KEY
Messaging I-KEY
Middleware I-KEY
to O
Ad O
Hoc O
Networking O
ABSTRACT O
The O
characteristics O
of O
mobile O
environments O
, O
with O
the O
possibility O
of O
frequent O
disconnections O
and O
fluctuating O
bandwidth O
, O
have O
forced O
a O
rethink O
of O
traditional O
middleware O
. O
In O
particular O
, O
the O
synchronous O
communication O
paradigms O
often O
employed O
in O
standard O
middleware O
do O
not O
appear O
to O
be O
particularly O
suited O
to O
ad O
hoc O
environments O
, O
in O
which O
not O
even O
the O
intermittent O
availability O
of O
a O
backbone O
network O
can O
be O
assumed O
. O
Instead O
, O
asynchronous B-KEY
communication I-KEY
seems O
to O
be O
a O
generally O
more O
suitable O
paradigm O
for O
such O
environments O
. O
Message B-KEY
oriented I-KEY
middleware I-KEY
for O
traditional O
systems O
has O
been O
developed O
and O
used O
to O
provide O
an O
asynchronous O
paradigm O
of O
communication O
for O
distributed O
systems O
, O
and O
, O
recently O
, O
also O
for O
some O
specific O
mobile O
computing O
systems O
. O
In O
this O
paper O
, O
we O
present O
our O
experience O
in O
designing O
, O
implementing O
and O
evaluating O
EMMA O
-LRB- O
Epidemic B-KEY
Messaging I-KEY
Middleware I-KEY
for O
Ad O
hoc O
networks O
-RRB- O
, O
an O
adaptation O
of O
Java B-KEY
Message I-KEY
Service I-KEY
-LRB- O
JMS O
-RRB- O
for O
mobile O
ad O
hoc O
environments O
. O
We O
discuss O
in O
detail O
the O
design O
challenges O
and O
some O
possible O
solutions O
, O
showing O
a O
concrete O
example O
of O
the O
feasibility O
and O
suitability O
of O
the O
application O
of O
the O
asynchronous O
paradigm O
in O
this O
setting O
and O
outlining O
a O
research O
roadmap O
for O
the O
coming O
years O
. O
A O
Hierarchical B-KEY
Process I-KEY
Execution I-KEY
Support O
for O
Grid O
Computing O
ABSTRACT O
Grid O
is O
an O
emerging O
infrastructure O
used O
to O
share O
resources O
among O
virtual O
organizations O
in O
a O
seamless O
manner O
and O
to O
provide O
breakthrough O
computing O
power O
at O
low O
cost O
. O
Nowadays O
there O
are O
dozens O
of O
academic O
and O
commercial O
products O
that O
allow O
execution O
of O
isolated O
tasks O
on O
grids O
, O
but O
few O
products O
support O
the O
enactment O
of O
long-running O
processes O
in O
a O
distributed O
fashion O
. O
In O
order O
to O
address O
such O
subject O
, O
this O
paper O
presents O
a O
programming O
model O
and O
an O
infrastructure O
that O
hierarchically O
schedules O
process O
activities O
using O
available O
nodes O
in O
a O
wide O
grid O
environment O
. O
Their O
advantages O
are O
automatic O
and O
structured O
distribution O
of O
activities O
and O
easy O
process O
monitoring O
and O
steering O
. O
Machine B-KEY
Learning I-KEY
for O
Information B-KEY
Architecture I-KEY
in O
a O
Large O
Governmental O
Website O
* O
ABSTRACT O
This O
paper O
describes O
ongoing O
research O
into O
the O
application O
of O
machine B-KEY
learning I-KEY
techniques O
for O
improving O
access O
to O
governmental O
information O
in O
complex O
digital O
libraries O
. O
Under O
the O
auspices O
of O
the O
GovStat O
Project O
, O
our O
goal O
is O
to O
identify O
a O
small O
number O
of O
semantically O
valid O
concepts O
that O
adequately O
spans O
the O
intellectual O
domain O
of O
a O
collection O
. O
The O
goal O
of O
this O
discovery O
is O
twofold O
. O
First O
we O
desire O
a O
practical O
aid O
for O
information O
architects O
. O
Second O
, O
automatically O
derived O
documentconcept O
relationships O
are O
a O
necessary O
precondition O
for O
realworld O
deployment O
of O
many O
dynamic O
interfaces O
. O
The O
current O
study O
compares O
concept O
learning O
strategies O
based O
on O
three O
document O
representations O
: O
keywords O
, O
titles O
, O
and O
full-text O
. O
In O
statistical O
and O
user-based O
studies O
, O
human-created O
keywords O
provide O
significant O
improvements O
in O
concept O
learning O
over O
both O
title-only O
and O
full-text O
representations O
. O
Network B-KEY
Monitors I-KEY
and O
Contracting O
Systems O
: O
Competition O
and O
Innovation O
ABSTRACT O
Today O
's O
Internet O
industry O
suffers O
from O
several O
well-known O
pathologies O
, O
but O
none O
is O
as O
destructive O
in O
the O
long O
term O
as O
its O
resistance O
to O
evolution O
. O
Rather O
than O
introducing O
new O
services O
, O
ISPs O
are O
presently O
moving O
towards O
greater O
commoditization B-KEY
. O
It O
is O
apparent O
that O
the O
network O
's O
primitive O
system O
of O
contracts B-KEY
does O
not O
align O
incentives B-KEY
properly O
. O
In O
this O
study O
, O
we O
identify O
the O
network O
's O
lack O
of O
accountability O
as O
a O
fundamental O
obstacle O
to O
correcting O
this O
problem O
: O
Employing O
an O
economic O
model O
, O
we O
argue O
that O
optimal O
routes O
and O
innovation B-KEY
are O
impossible O
unless O
new O
monitoring B-KEY
capability O
is O
introduced O
and O
incorporated O
with O
the O
contracting B-KEY
system O
. O
Furthermore O
, O
we O
derive O
the O
minimum O
requirements O
a O
monitoring B-KEY
system O
must O
meet O
to O
support O
first-best O
routing O
and O
innovation B-KEY
characteristics O
. O
Our O
work O
does O
not O
constitute O
a O
new O
protocol O
; O
rather O
, O
we O
provide O
practical O
and O
specific O
guidance O
for O
the O
design O
of O
monitoring B-KEY
systems O
, O
as O
well O
as O
a O
theoretical O
framework O
to O
explore O
the O
factors O
that O
influence O
innovation B-KEY
. O
Agents O
, O
Beliefs B-KEY
, O
and O
Plausible B-KEY
Behavior O
in O
a O
Temporal O
Setting O
ABSTRACT O
Logics B-KEY
of O
knowledge O
and O
belief B-KEY
are O
often O
too O
static O
and O
inflexible O
to O
be O
used O
on O
real-world O
problems O
. O
In O
particular O
, O
they O
usually O
offer O
no O
concept O
for O
expressing O
that O
some O
course O
of O
events O
is O
more O
likely O
to O
happen O
than O
another O
. O
We O
address O
this O
problem O
and O
extend O
CTLK O
-LRB- O
computation B-KEY
tree I-KEY
logic I-KEY
with O
knowledge O
-RRB- O
with O
a O
notion O
of O
plausibility O
, O
which O
allows O
for O
practical O
and O
counterfactual O
reasoning O
. O
The O
new O
logic B-KEY
CTLKP O
-LRB- O
CTLK O
with O
plausibility B-KEY
-RRB- O
includes O
also O
a O
particular O
notion B-KEY
of I-KEY
belief I-KEY
. O
A O
plausibility B-KEY
update O
operator O
is O
added O
to O
this O
logic O
in O
order O
to O
change O
plausibility O
assumptions O
dynamically O
. O
Furthermore O
, O
we O
examine O
some O
important O
properties O
of O
these O
concepts O
. O
In O
particular O
, O
we O
show O
that O
, O
for O
a O
natural O
class O
of O
models O
, O
belief B-KEY
is O
a O
KD45 O
modality O
. O
We O
also O
show O
that O
model O
checking O
CTLKP O
is O
PTIME-complete O
and O
can O
be O
done O
in O
time O
linear O
with O
respect O
to O
the O
size O
of O
models O
and O
formulae O
. O
Modular B-KEY
Interpreted I-KEY
Systems I-KEY
ABSTRACT O
We O
propose O
a O
new O
class O
of O
representations O
that O
can O
be O
used O
for O
modeling O
-LRB- O
and O
model B-KEY
checking I-KEY
-RRB- O
temporal O
, O
strategic O
and O
epistemic O
properties O
of O
agents O
and O
their O
teams O
. O
Our O
representations O
borrow O
the O
main O
ideas O
from O
interpreted O
systems O
of O
Halpern O
, O
Fagin O
et O
al. O
; O
however O
, O
they O
are O
also O
modular O
and O
compact O
in O
the O
way O
concurrent O
programs O
are O
. O
We O
also O
mention O
preliminary O
results O
on O
model B-KEY
checking I-KEY
alternating-time O
temporal O
logic O
for O
this O
natural O
class O
of O
models O
. O
Learning O
Consumer B-KEY
Preferences I-KEY
Using O
Semantic B-KEY
Similarity I-KEY
∗ O
Reyhan O
Aydo˘gan O
Pınar O
Yolum O
ABSTRACT O
In O
online O
, O
dynamic O
environments O
, O
the O
services B-KEY
requested O
by O
consumers O
may O
not O
be O
readily O
served O
by O
the O
providers O
. O
This O
requires O
the O
service B-KEY
consumers O
and O
providers O
to O
negotiate B-KEY
their O
service B-KEY
needs O
and O
offers O
. O
Multiagent O
negotiation B-KEY
approaches O
typically O
assume O
that O
the O
parties O
agree O
on O
service B-KEY
content O
and O
focus O
on O
finding O
a O
consensus O
on O
service B-KEY
price B-KEY
. O
In O
contrast O
, O
this O
work O
develops O
an O
approach O
through O
which O
the O
parties O
can O
negotiate B-KEY
the O
content O
of O
a O
service B-KEY
. O
This O
calls O
for O
a O
negotiation B-KEY
approach O
in O
which O
the O
parties O
can O
understand O
the O
semantics O
of O
their O
requests O
and O
offers O
and O
learn O
each O
other O
's O
preferences O
incrementally O
over O
time O
. O
Accordingly O
, O
we O
propose O
an O
architecture O
in O
which O
both O
consumers O
and O
producers O
use O
a O
shared O
ontology B-KEY
to O
negotiate B-KEY
a O
service B-KEY
. O
Through O
repetitive O
interactions O
, O
the O
provider O
learns O
consumers O
' O
needs O
accurately O
and O
can O
make O
better O
targeted O
offers O
. O
To O
enable O
fast O
and O
accurate O
learning O
of O
preferences O
, O
we O
develop O
an O
extension O
to O
Version O
Space O
and O
compare O
it O
with O
existing O
learning O
techniques O
. O
We O
further O
develop O
a O
metric O
for O
measuring O
semantic B-KEY
similarity I-KEY
between O
services B-KEY
and O
compare O
the O
performance O
of O
our O
approach O
using O
different O
similarity B-KEY
metrics I-KEY
. O
The O
LOGIC O
Negotiation B-KEY
Model O
ABSTRACT O
Successful O
negotiators B-KEY
prepare O
by O
determining O
their O
position O
along O
five O
dimensions O
: O
Legitimacy O
, O
Options O
, O
Goals O
, O
Independence O
, O
and O
Commitment O
, O
-LRB- O
LOGIC O
-RRB- O
. O
We O
introduce O
a O
negotiation B-KEY
model O
based O
on O
these O
dimensions O
and O
on O
two O
primitive O
concepts O
: O
intimacy O
-LRB- O
degree O
of O
closeness O
-RRB- O
and O
balance O
-LRB- O
degree O
of O
fairness O
-RRB- O
. O
The O
intimacy O
is O
a O
pair O
of O
matrices O
that O
evaluate O
both O
an O
agent O
's O
contribution O
to O
the O
relationship O
and O
its O
opponent O
's O
contribution O
each O
from O
an O
information O
view O
and O
from O
a O
utilitarian O
view O
across O
the O
five O
LOGIC O
dimensions O
. O
The O
balance O
is O
the O
difference O
between O
these O
matrices O
. O
A O
relationship O
strategy O
maintains O
a O
target O
intimacy O
for O
each O
relationship O
that O
an O
agent O
would O
like O
the O
relationship O
to O
move O
towards O
in O
future O
. O
The O
negotiation B-KEY
strategy O
maintains O
a O
set O
of O
Options O
that O
are O
in-line O
with O
the O
current O
intimacy O
level O
, O
and O
then O
tactics O
wrap O
the O
Options O
in O
argumentation O
with O
the O
aim O
of O
attaining O
a O
successful O
deal O
and O
manipulating O
the O
successive O
negotiation O
balances O
towards O
the O
target O
intimacy O
. O
A O
Frequency-based O
and O
a O
Poisson-based O
Definition O
of O
the O
Probability O
of O
Being O
Informative B-KEY
ABSTRACT O
This O
paper O
reports O
on O
theoretical O
investigations O
about O
the O
assumptions O
underlying O
the O
inverse B-KEY
document I-KEY
frequency I-KEY
-LRB- O
idf B-KEY
-RRB- O
. O
We O
show O
that O
an O
intuitive O
idf B-KEY
- O
based O
probability B-KEY
function I-KEY
for O
the O
probability O
of O
a O
term O
being O
informative B-KEY
assumes O
disjoint O
document O
events O
. O
By O
assuming O
documents O
to O
be O
independent O
rather O
than O
disjoint O
, O
we O
arrive O
at O
a O
Poisson-based O
probability O
of O
being O
informative B-KEY
. O
The O
framework O
is O
useful O
for O
understanding O
and O
deciding O
the O
parameter O
estimation O
and O
combination O
in O
probabilistic O
retrieval O
models O
. O
Controlling O
Overlap O
in O
Content-Oriented O
XML B-KEY
Retrieval O
ABSTRACT O
The O
direct O
application O
of O
standard O
ranking B-KEY
techniques O
to O
retrieve O
individual O
elements O
from O
a O
collection O
of O
XML B-KEY
documents O
often O
produces O
a O
result O
set O
in O
which O
the O
top O
ranks B-KEY
are O
dominated O
by O
a O
large O
number O
of O
elements O
taken O
from O
a O
small O
number O
of O
highly O
relevant O
documents O
. O
This O
paper O
presents O
and O
evaluates O
an O
algorithm O
that O
re-ranks O
this O
result O
set O
, O
with O
the O
aim O
of O
minimizing O
redundant O
content O
while O
preserving O
the O
benefits O
of O
element O
retrieval O
, O
including O
the O
benefit O
of O
identifying O
topic-focused O
components O
contained O
within O
relevant O
documents O
. O
The O
test O
collection O
developed O
by O
the O
INitiative O
for O
the O
Evaluation O
of O
XML B-KEY
Retrieval O
-LRB- O
INEX B-KEY
-RRB- O
forms O
the O
basis O
for O
the O
evaluation O
. O
A O
Multi-Agent O
System O
for O
Building O
Dynamic O
Ontologies B-KEY
ABSTRACT O
Ontologies B-KEY
building O
from O
text O
is O
still O
a O
time-consuming O
task O
which O
justifies O
the O
growth O
of O
Ontology B-KEY
Learning O
. O
Our O
system O
named O
Dynamo B-KEY
is O
designed O
along O
this O
domain O
but O
following O
an O
original O
approach O
based O
on O
an O
adaptive O
multi-agent O
architecture O
. O
In O
this O
paper O
we O
present O
a O
distributed O
hierarchical O
clustering O
algorithm O
, O
core O
of O
our O
approach O
. O
It O
is O
evaluated O
and O
compared O
to O
a O
more O
conventional O
centralized O
algorithm O
. O
We O
also O
present O
how O
it O
has O
been O
improved O
using O
a O
multi-criteria O
approach O
. O
With O
those O
results O
in O
mind O
, O
we O
discuss O
the O
limits O
of O
our O
system O
and O
add O
as O
perspectives O
the O
modifications O
required O
to O
reach O
a O
complete O
ontology B-KEY
building O
solution O
. O
Remote B-KEY
Access I-KEY
to O
Large O
Spatial O
Databases O
* O
ABSTRACT O
Enterprises O
in O
the O
public O
and O
private O
sectors O
have O
been O
making O
their O
large B-KEY
spatial I-KEY
data I-KEY
archives O
available O
over O
the O
Internet B-KEY
. O
However O
, O
interactive O
work O
with O
such O
large O
volumes O
of O
online O
spatial O
data O
is O
a O
challenging O
task O
. O
We O
propose O
two O
efficient O
approaches O
to O
remote B-KEY
access I-KEY
to O
large B-KEY
spatial I-KEY
data I-KEY
. O
First O
, O
we O
introduce O
a O
client-server O
architecture O
where O
the O
work O
is O
distributed O
between O
the O
server O
and O
the O
individual O
clients O
for O
spatial B-KEY
query I-KEY
evaluation I-KEY
, O
data B-KEY
visualization I-KEY
, O
and O
data B-KEY
management I-KEY
. O
We O
enable O
the O
minimization O
of O
the O
requirements O
for O
system O
resources O
on O
the O
client O
side O
while O
maximizing O
system O
responsiveness O
as O
well O
as O
the O
number O
of O
connections O
one O
server O
can O
handle O
concurrently O
. O
Second O
, O
for O
prolonged O
periods O
of O
access O
to O
large O
online O
data O
, O
we O
introduce O
APPOINT O
-LRB- O
an O
Approach O
for O
Peer-to-Peer O
Offloading O
the O
INTernet B-KEY
-RRB- O
. O
This O
is O
a O
centralized O
peer-to-peer O
approach O
that O
helps O
Internet B-KEY
users O
transfer O
large O
volumes O
of O
online O
data O
efficiently O
. O
In O
APPOINT O
, O
active O
clients O
of O
the O
clientserver O
architecture O
act O
on O
the O
server O
's O
behalf O
and O
communicate O
with O
each O
other O
to O
decrease O
network B-KEY
latency I-KEY
, O
improve O
service O
bandwidth O
, O
and O
resolve O
server O
congestions O
. O
Combining B-KEY
Content I-KEY
and I-KEY
Link I-KEY
for O
Classification B-KEY
using O
Matrix B-KEY
Factorization I-KEY
ABSTRACT O
The O
world O
wide O
web O
contains O
rich O
textual O
contents O
that O
are O
interconnected O
via O
complex O
hyperlinks O
. O
This O
huge O
database O
violates O
the O
assumption O
held O
by O
most O
of O
conventional O
statistical O
methods O
that O
each O
web O
page O
is O
considered O
as O
an O
independent O
and O
identical O
sample O
. O
It O
is O
thus O
difficult O
to O
apply O
traditional O
mining O
or O
learning O
methods O
for O
solving O
web B-KEY
mining I-KEY
problems I-KEY
, O
e.g. O
, O
web O
page O
classification B-KEY
, O
by O
exploiting O
both O
the O
content O
and O
the O
link B-KEY
structure I-KEY
. O
The O
research O
in O
this O
direction O
has O
recently O
received O
considerable O
attention O
but O
are O
still O
in O
an O
early O
stage O
. O
Though O
a O
few O
methods O
exploit O
both O
the O
link B-KEY
structure I-KEY
or O
the O
content B-KEY
information I-KEY
, O
some O
of O
them O
combine O
the O
only O
authority B-KEY
information I-KEY
with O
the O
content B-KEY
information I-KEY
, O
and O
the O
others O
first O
decompose O
the O
link B-KEY
structure I-KEY
into O
hub O
and O
authority O
features O
, O
then O
apply O
them O
as O
additional O
document O
features O
. O
Being O
practically O
attractive O
for O
its O
great O
simplicity O
, O
this O
paper O
aims O
to O
design O
an O
algorithm O
that O
exploits O
both O
the O
content O
and O
linkage O
information O
, O
by O
carrying O
out O
a O
joint B-KEY
factorization I-KEY
on O
both O
the O
linkage B-KEY
adjacency I-KEY
matrix I-KEY
and O
the O
document-term B-KEY
matrix I-KEY
, O
and O
derives O
a O
new O
representation O
for O
web O
pages O
in O
a O
low-dimensional B-KEY
factor I-KEY
space I-KEY
, O
without O
explicitly O
separating O
them O
as O
content O
, O
hub O
or O
authority O
factors O
. O
Further O
analysis O
can O
be O
performed O
based O
on O
the O
compact O
representation O
of O
web O
pages O
. O
In O
the O
experiments O
, O
the O
proposed O
method O
is O
compared O
with O
state-of-the-art O
methods O
and O
demonstrates O
an O
excellent O
accuracy O
in O
hypertext O
classification B-KEY
on O
the O
WebKB B-KEY
and I-KEY
Cora I-KEY
benchmarks I-KEY
. O
Event B-KEY
Threading O
within O
News O
Topics O
ABSTRACT O
With O
the O
overwhelming O
volume O
of O
online O
news O
available O
today O
, O
there O
is O
an O
increasing O
need O
for O
automatic B-KEY
techniques I-KEY
to O
analyze O
and O
present O
news O
to O
the O
user O
in O
a O
meaningful O
and O
efficient O
manner O
. O
Previous O
research O
focused O
only O
on O
organizing O
news O
stories O
by O
their O
topics O
into O
a O
flat B-KEY
hierarchy I-KEY
. O
We O
believe O
viewing O
a O
news O
topic O
as O
a O
flat O
collection O
of O
stories O
is O
too O
restrictive O
and O
inefficient O
for O
a O
user O
to O
understand O
the O
topic O
quickly O
. O
In O
this O
work O
, O
we O
attempt O
to O
capture O
the O
rich O
structure O
of O
events B-KEY
and O
their O
dependencies B-KEY
in O
a O
news O
topic O
through O
our O
event B-KEY
models O
. O
We O
call O
the O
process O
of O
recognizing O
events B-KEY
and O
their O
dependencies B-KEY
event B-KEY
threading O
. O
We O
believe O
our O
perspective O
of O
modeling O
the O
structure O
of O
a O
topic O
is O
more O
effective O
in O
capturing O
its O
semantics O
than O
a O
flat O
list O
of O
on-topic O
stories O
. O
We O
formally O
define O
the O
novel O
problem O
, O
suggest O
evaluation O
metrics O
and O
present O
a O
few O
techniques O
for O
solving O
the O
problem O
. O
Besides O
the O
standard O
word O
based O
features O
, O
our O
approaches O
take O
into O
account O
novel B-KEY
features I-KEY
such O
as O
temporal B-KEY
locality I-KEY
of O
stories O
for O
event B-KEY
recognition O
and O
time-ordering O
for O
capturing O
dependencies O
. O
Our O
experiments O
on O
a O
manually O
labeled O
data O
sets O
show O
that O
our O
models O
effectively O
identify O
the O
events B-KEY
and O
capture O
dependencies B-KEY
among O
them O
. O
A O
Cross-Layer O
Approach O
to O
Resource B-KEY
Discovery I-KEY
and O
Distribution O
in O
Mobile O
Ad O
hoc O
Networks O
ABSTRACT O
This O
paper O
describes O
a O
cross-layer O
approach O
to O
designing O
robust O
P2P O
system O
over O
mobile O
ad O
hoc O
networks O
. O
The O
design O
is O
based O
on O
simple O
functional O
primitives O
that O
allow O
routing O
at O
both O
P2P O
and O
network O
layers O
to O
be O
integrated O
to O
reduce O
overhead O
. O
With O
these O
primitives O
, O
the O
paper O
addresses O
various O
load O
balancing O
techniques O
. O
Preliminary O
simulation O
results O
are O
also O
presented O
. O
Concept O
and O
Architecture O
of O
a O
Pervasive B-KEY
Document I-KEY
Editing I-KEY
and I-KEY
Managing I-KEY
System I-KEY
ABSTRACT O
Collaborative B-KEY
document I-KEY
processing O
has O
been O
addressed O
by O
many O
approaches O
so O
far O
, O
most O
of O
which O
focus O
on O
document O
versioning O
and O
collaborative O
editing O
. O
We O
address O
this O
issue O
from O
a O
different O
angle O
and O
describe O
the O
concept O
and O
architecture O
of O
a O
pervasive B-KEY
document I-KEY
editing I-KEY
and I-KEY
managing I-KEY
system I-KEY
. O
It O
exploits O
database O
techniques O
and O
real-time O
updating O
for O
sophisticated O
collaboration O
scenarios O
on O
multiple O
devices O
. O
Each O
user O
is O
always O
served O
with O
upto-date O
documents O
and O
can O
organize O
his O
work O
based O
on O
document O
meta O
data O
. O
For O
this O
, O
we O
present O
our O
conceptual O
architecture O
for O
such O
a O
system O
and O
discuss O
it O
with O
an O
example O
. O
Finding O
Equilibria O
in O
Large O
Sequential B-KEY
Games I-KEY
of O
Imperfect B-KEY
Information I-KEY
* O
ABSTRACT O
Finding O
an O
equilibrium B-KEY
of O
an O
extensive O
form O
game O
of O
imperfect B-KEY
information I-KEY
is O
a O
fundamental O
problem O
in O
computational B-KEY
game I-KEY
theory I-KEY
, O
but O
current O
techniques O
do O
not O
scale O
to O
large O
games O
. O
To O
address O
this O
, O
we O
introduce O
the O
ordered B-KEY
game I-KEY
isomorphism I-KEY
and O
the O
related O
ordered B-KEY
game I-KEY
isomorphic I-KEY
abstraction O
transformation O
. O
For O
a O
multi-player O
sequential B-KEY
game I-KEY
of O
imperfect B-KEY
information I-KEY
with O
observable O
actions O
and O
an O
ordered O
signal O
space O
, O
we O
prove O
that O
any O
Nash O
equilibrium O
in O
an O
abstracted O
smaller O
game O
, O
obtained O
by O
one O
or O
more O
applications O
of O
the O
transformation O
, O
can O
be O
easily O
converted O
into O
a O
Nash O
equilibrium O
in O
the O
original O
game O
. O
We O
present O
an O
algorithm O
, O
GameShrink B-KEY
, O
for O
abstracting O
the O
game O
using O
our O
isomorphism O
exhaustively O
. O
Its O
complexity O
is O
˜O O
-LRB- O
n2 O
-RRB- O
, O
where O
n O
is O
the O
number O
of O
nodes O
in O
a O
structure O
we O
call O
the O
signal B-KEY
tree I-KEY
. O
It O
is O
no O
larger O
than O
the O
game O
tree O
, O
and O
on O
nontrivial O
games O
it O
is O
drastically O
smaller O
, O
so O
GameShrink B-KEY
has O
time O
and O
space O
complexity O
sublinear O
in O
the O
size O
of O
the O
game O
tree O
. O
Using O
GameShrink B-KEY
, O
we O
find O
an O
equilibrium B-KEY
to O
a O
poker O
game O
with O
3.1 O
billion O
nodes O
-- O
over O
four O
orders O
of O
magnitude O
more O
than O
in O
the O
largest O
poker O
game O
solved O
previously O
. O
We O
discuss O
several O
electronic O
commerce O
applications O
for O
GameShrink B-KEY
. O
To O
address O
even O
larger O
games O
, O
we O
introduce O
approximation O
methods O
that O
do O
not O
preserve O
equilibrium B-KEY
, O
but O
nevertheless O
yield O
-LRB- O
ex O
post O
-RRB- O
provably O
close-to-optimal O
strategies O
. O
On O
the O
relevance B-KEY
of O
utterances O
in O
formal O
inter-agent O
dialogues B-KEY
ABSTRACT O
Work O
on O
argumentation-based O
dialogue B-KEY
has O
defined O
frameworks O
within O
which O
dialogues B-KEY
can O
be O
carried O
out O
, O
established O
protocols O
that O
govern O
dialogues B-KEY
, O
and O
studied O
different O
properties O
of O
dialogues B-KEY
. O
This O
work O
has O
established O
the O
space O
in O
which O
agents O
are O
permitted O
to O
interact O
through O
dialogues B-KEY
. O
Recently O
, O
there O
has O
been O
increasing O
interest O
in O
the O
mechanisms O
agents O
might O
use O
to O
choose O
how O
to O
act O
-- O
the O
rhetorical O
manoeuvring O
that O
they O
use O
to O
navigate O
through O
the O
space O
defined O
by O
the O
rules O
of O
the O
dialogue B-KEY
. O
Key O
in O
such O
considerations O
is O
the O
idea O
of O
relevance B-KEY
, O
since O
a O
usual O
requirement O
is O
that O
agents O
stay O
focussed O
on O
the O
subject O
of O
the O
dialogue B-KEY
and O
only O
make O
relevant B-KEY
remarks O
. O
Here O
we O
study O
several O
notions O
of O
relevance B-KEY
, O
showing O
how O
they O
can O
be O
related O
to O
both O
the O
rules O
for O
carrying O
out O
dialogues B-KEY
and O
to O
rhetorical O
manoeuvring O
. O
A O
Randomized O
Method O
for O
the O
Shapley O
Value O
for O
the O
Voting O
Game O
ABSTRACT O
The O
Shapley O
value O
is O
one O
of O
the O
key O
solution O
concepts O
for O
coalition O
games O
. O
Its O
main O
advantage O
is O
that O
it O
provides O
a O
unique B-KEY
and I-KEY
fair I-KEY
solution I-KEY
, O
but O
its O
main O
problem O
is O
that O
, O
for O
many O
coalition O
games O
, O
the O
Shapley O
value O
can O
not O
be O
determined O
in O
polynomial B-KEY
time I-KEY
. O
In O
particular O
, O
the O
problem O
of O
finding O
this O
value O
for O
the O
voting O
game O
is O
known O
to O
be O
#P O
- O
complete O
in O
the O
general O
case O
. O
However O
, O
in O
this O
paper O
, O
we O
show O
that O
there O
are O
some O
specific O
voting O
games O
for O
which O
the O
problem O
is O
computationally O
tractable O
. O
For O
other O
general O
voting O
games O
, O
we O
overcome O
the O
problem O
of O
computational O
complexity O
by O
presenting O
a O
new O
randomized O
method O
for O
determining O
the O
approximate B-KEY
Shapley O
value O
. O
The O
time O
complexity O
of O
this O
method O
is O
linear O
in O
the O
number O
of O
players O
. O
We O
also O
show O
, O
through O
empirical O
studies O
, O
that O
the O
percentage O
error O
for O
the O
proposed O
method O
is O
always O
less O
than O
20 O
% O
and O
, O
in O
most O
cases O
, O
less O
than O
5 O
% O
. O
Automatic O
Extraction O
of O
Titles O
from O
General O
Documents O
using O
Machine B-KEY
Learning I-KEY
ABSTRACT O
In O
this O
paper O
, O
we O
propose O
a O
machine B-KEY
learning I-KEY
approach O
to O
title B-KEY
extraction I-KEY
from O
general O
documents O
. O
By O
general O
documents O
, O
we O
mean O
documents O
that O
can O
belong O
to O
any O
one O
of O
a O
number O
of O
specific O
genres B-KEY
, O
including O
presentations O
, O
book O
chapters O
, O
technical O
papers O
, O
brochures O
, O
reports O
, O
and O
letters O
. O
Previously O
, O
methods O
have O
been O
proposed O
mainly O
for O
title B-KEY
extraction I-KEY
from O
research O
papers O
. O
It O
has O
not O
been O
clear O
whether O
it O
could O
be O
possible O
to O
conduct O
automatic B-KEY
title I-KEY
extraction I-KEY
from O
general O
documents O
. O
As O
a O
case O
study O
, O
we O
consider O
extraction O
from O
Office O
including O
Word O
and O
PowerPoint O
. O
In O
our O
approach O
, O
we O
annotate O
titles O
in O
sample O
documents O
-LRB- O
for O
Word O
and O
PowerPoint O
respectively O
-RRB- O
and O
take O
them O
as O
training O
data O
, O
train O
machine B-KEY
learning I-KEY
models O
, O
and O
perform O
title B-KEY
extraction I-KEY
using O
the O
trained O
models O
. O
Our O
method O
is O
unique O
in O
that O
we O
mainly O
utilize O
formatting B-KEY
information I-KEY
such O
as O
font O
size O
as O
features O
in O
the O
models O
. O
It O
turns O
out O
that O
the O
use O
of O
formatting B-KEY
information I-KEY
can O
lead O
to O
quite O
accurate O
extraction O
from O
general O
documents O
. O
Precision O
and O
recall O
for O
title B-KEY
extraction I-KEY
from O
Word O
is O
0.810 O
and O
0.837 O
respectively O
, O
and O
precision O
and O
recall O
for O
title B-KEY
extraction I-KEY
from O
PowerPoint O
is O
0.875 O
and O
0.895 O
respectively O
in O
an O
experiment O
on O
intranet O
data O
. O
Other O
important O
new O
findings O
in O
this O
work O
include O
that O
we O
can O
train O
models O
in O
one O
domain O
and O
apply O
them O
to O
another O
domain O
, O
and O
more O
surprisingly O
we O
can O
even O
train O
models O
in O
one O
language O
and O
apply O
them O
to O
another O
language O
. O
Moreover O
, O
we O
can O
significantly O
improve O
search B-KEY
ranking O
results O
in O
document B-KEY
retrieval I-KEY
by O
using O
the O
extracted O
titles O
. O
Context-Sensitive O
Information O
Retrieval O
Using O
Implicit O
Feedback O
ABSTRACT O
A O
major O
limitation O
of O
most O
existing O
retrieval O
models O
and O
systems O
is O
that O
the O
retrieval O
decision O
is O
made O
based O
solely O
on O
the O
query O
and O
document O
collection O
; O
information O
about O
the O
actual O
user O
and O
search O
context B-KEY
is O
largely O
ignored O
. O
In O
this O
paper O
, O
we O
study O
how O
to O
exploit O
implicit B-KEY
feedback I-KEY
information I-KEY
, O
including O
previous O
queries O
and O
clickthrough B-KEY
information I-KEY
, O
to O
improve O
retrieval B-KEY
accuracy I-KEY
in O
an O
interactive O
information O
retrieval O
setting O
. O
We O
propose O
several O
contextsensitive O
retrieval O
algorithms O
based O
on O
statistical O
language O
models O
to O
combine O
the O
preceding O
queries O
and O
clicked O
document O
summaries O
with O
the O
current B-KEY
query I-KEY
for O
better O
ranking O
of O
documents O
. O
We O
use O
the O
TREC O
AP O
data O
to O
create O
a O
test O
collection O
with O
search O
context B-KEY
information O
, O
and O
quantitatively O
evaluate O
our O
models O
using O
this O
test O
set O
. O
Experiment O
results O
show O
that O
using O
implicit O
feedback O
, O
especially O
the O
clicked O
document O
summaries O
, O
can O
improve O
retrieval O
performance O
substantially O
. O
Competitive B-KEY
Algorithms I-KEY
for O
VWAP B-KEY
and O
Limit O
Order O
Trading O
ABSTRACT O
We O
introduce O
new O
online B-KEY
models I-KEY
for O
two O
important O
aspects O
of O
modern B-KEY
financial I-KEY
markets I-KEY
: O
Volume O
Weighted O
Average O
Price O
trading O
and O
limit O
order O
books O
. O
We O
provide O
an O
extensive O
study O
of O
competitive B-KEY
algorithms I-KEY
in O
these O
models O
and O
relate O
them O
to O
earlier O
online B-KEY
algorithms I-KEY
for O
stock B-KEY
trading I-KEY
. O
A O
Formal O
Model O
for O
Situated O
Semantic B-KEY
Alignment I-KEY
ABSTRACT O
Ontology B-KEY
matching O
is O
currently O
a O
key O
technology O
to O
achieve O
the O
semantic B-KEY
alignment I-KEY
of O
ontological B-KEY
entities O
used O
by O
knowledge-based O
applications O
, O
and O
therefore O
to O
enable O
their O
interoperability O
in O
distributed O
environments O
such O
as O
multiagent O
systems O
. O
Most O
ontology B-KEY
matching O
mechanisms O
, O
however O
, O
assume O
matching O
prior O
integration O
and O
rely O
on O
semantics O
that O
has O
been O
coded O
a O
priori O
in O
concept O
hierarchies O
or O
external O
sources O
. O
In O
this O
paper O
, O
we O
present O
a O
formal O
model O
for O
a O
semantic B-KEY
alignment I-KEY
procedure O
that O
incrementally O
aligns O
differing O
conceptualisations O
of O
two O
or O
more O
agents O
relative O
to O
their O
respective O
perception O
of O
the O
environment O
or O
domain O
they O
are O
acting O
in O
. O
It O
hence O
makes O
the O
situation O
in O
which O
the O
alignment O
occurs O
explicit O
in O
the O
model O
. O
We O
resort O
to O
Channel O
Theory O
to O
carry O
out O
the O
formalisation O
. O
Robustness B-KEY
of O
Adaptive B-KEY
Filtering I-KEY
Methods O
In O
a O
Cross-benchmark B-KEY
Evaluation I-KEY
ABSTRACT O
This O
paper O
reports O
a O
cross-benchmark B-KEY
evaluation I-KEY
of O
regularized B-KEY
logistic B-KEY
regression I-KEY
-LRB- O
LR B-KEY
-RRB- O
and O
incremental O
Rocchio B-KEY
for O
adaptive B-KEY
filtering I-KEY
. O
Using O
four O
corpora O
from O
the O
Topic B-KEY
Detection I-KEY
and O
Tracking O
-LRB- O
TDT O
-RRB- O
forum O
and O
the O
Text O
Retrieval O
Conferences O
-LRB- O
TREC O
-RRB- O
we O
evaluated O
these O
methods O
with O
non-stationary O
topics O
at O
various O
granularity O
levels O
, O
and O
measured O
performance O
with O
different O
utility O
settings O
. O
We O
found O
that O
LR B-KEY
performs O
strongly O
and O
robustly O
in O
optimizing O
T11SU O
-LRB- O
a O
TREC O
utility B-KEY
function I-KEY
-RRB- O
while O
Rocchio B-KEY
is O
better O
for O
optimizing O
Ctrk O
-LRB- O
the O
TDT O
tracking O
cost O
-RRB- O
, O
a O
high-recall O
oriented O
objective O
function O
. O
Using O
systematic O
cross-corpus B-KEY
parameter I-KEY
optimization I-KEY
with O
both O
methods O
, O
we O
obtained O
the O
best O
results O
ever O
reported O
on O
TDT5 O
, O
TREC10 O
and O
TREC11 O
. O
Relevance B-KEY
feedback I-KEY
on O
a O
small O
portion O
-LRB- O
0.05 O
~ O
0.2 O
% O
-RRB- O
of O
the O
TDT5 O
test O
documents O
yielded O
significant O
performance O
improvements O
, O
measuring O
up O
to O
a O
54 O
% O
reduction O
in O
Ctrk O
and O
a O
20.9 O
% O
increase O
in O
T11SU O
-LRB- O
with O
β O
= O
0.1 O
-RRB- O
, O
compared O
to O
the O
results O
of O
the O
top-performing O
system O
in O
TDT2004 O
without O
relevance B-KEY
feedback I-KEY
information O
. O
Operational B-KEY
Semantics I-KEY
of O
Multiagent B-KEY
Interactions I-KEY
ABSTRACT O
The O
social O
stance O
advocated O
by O
institutional B-KEY
frameworks I-KEY
and O
most O
multi-agent O
system O
methodologies O
has O
resulted O
in O
a O
wide O
spectrum O
of O
organizational B-KEY
and I-KEY
communicative I-KEY
abstractions I-KEY
which O
have O
found O
currency O
in O
several O
programming O
frameworks O
and O
software O
platforms O
. O
Still O
, O
these O
tools O
and O
frameworks O
are O
designed O
to O
support O
a O
limited O
range O
of O
interaction O
capabilities O
that O
constrain O
developers O
to O
a O
fixed O
set O
of O
particular O
, O
pre-defined B-KEY
abstractions I-KEY
. O
The O
main O
hypothesis O
motivating O
this O
paper O
is O
that O
the O
variety O
of O
multi-agent O
interaction O
mechanisms O
-- O
both O
, O
organizational O
and O
communicative O
, O
share O
a O
common O
semantic O
core O
. O
In O
the O
realm O
of O
software B-KEY
architectures I-KEY
, O
the O
paper O
proposes O
a O
connector-based O
model O
of O
multi-agent O
interactions O
which O
attempts O
to O
identify O
the O
essential O
structure O
underlying O
multi-agent O
interactions O
. O
Furthermore O
, O
the O
paper O
also O
provides O
this O
model O
with O
a O
formal B-KEY
execution I-KEY
semantics I-KEY
which O
describes O
the O
dynamics O
of O
social B-KEY
interactions I-KEY
. O
The O
proposed O
model O
is O
intended O
as O
the O
abstract O
machine O
of O
an O
organizational B-KEY
programming I-KEY
language I-KEY
which O
allows O
programmers O
to O
accommodate O
an O
open O
set O
of O
interaction O
mechanisms O
. O
Evaluating O
Opportunistic O
Routing B-KEY
Protocols O
with O
Large O
Realistic O
Contact O
Traces O
ABSTRACT O
Traditional O
mobile O
ad O
hoc O
network O
-LRB- O
MANET O
-RRB- O
routing B-KEY
protocols O
assume O
that O
contemporaneous O
end-to-end O
communication O
paths O
exist O
between O
data O
senders O
and O
receivers O
. O
In O
some O
mobile O
ad O
hoc O
networks O
with O
a O
sparse O
node O
population O
, O
an O
end-to-end O
communication O
path O
may O
break O
frequently O
or O
may O
not O
exist O
at O
any O
time O
. O
Many O
routing B-KEY
protocols O
have O
been O
proposed O
in O
the O
literature O
to O
address O
the O
problem O
, O
but O
few O
were O
evaluated O
in O
a O
realistic O
`` O
opportunistic O
'' O
network O
setting O
. O
We O
use O
simulation B-KEY
and O
contact B-KEY
traces I-KEY
-LRB- O
derived O
from O
logs O
in O
a O
production O
network O
-RRB- O
to O
evaluate O
and O
compare O
five O
existing O
protocols O
: O
direct-delivery O
, O
epidemic O
, O
random O
, O
PRoPHET B-KEY
, O
and O
Link-State O
, O
as O
well O
as O
our O
own O
proposed O
routing B-KEY
protocol O
. O
We O
show O
that O
the O
direct O
delivery O
and O
epidemic O
routing B-KEY
protocols O
suffer O
either O
low O
delivery O
ratio O
or O
high O
resource O
usage O
, O
and O
other O
protocols O
make O
tradeoffs O
between O
delivery O
ratio O
and O
resource O
usage O
. O
AdaRank O
: O
A O
Boosting B-KEY
Algorithm O
for O
Information B-KEY
Retrieval I-KEY
ABSTRACT O
In O
this O
paper O
we O
address O
the O
issue O
of O
learning B-KEY
to I-KEY
rank I-KEY
for O
document B-KEY
retrieval I-KEY
. O
In O
the O
task O
, O
a O
model O
is O
automatically O
created O
with O
some O
training O
data O
and O
then O
is O
utilized O
for O
ranking O
of O
documents O
. O
The O
goodness O
of O
a O
model O
is O
usually O
evaluated O
with O
performance O
measures O
such O
as O
MAP O
-LRB- O
Mean O
Average O
Precision O
-RRB- O
and O
NDCG O
-LRB- O
Normalized O
Discounted O
Cumulative O
Gain O
-RRB- O
. O
Ideally O
a O
learning O
algorithm O
would O
train O
a O
ranking B-KEY
model I-KEY
that O
could O
directly O
optimize O
the O
performance O
measures O
with O
respect O
to O
the O
training O
data O
. O
Existing O
methods O
, O
however O
, O
are O
only O
able O
to O
train B-KEY
ranking I-KEY
models I-KEY
by O
minimizing O
loss O
functions O
loosely O
related O
to O
the O
performance O
measures O
. O
For O
example O
, O
Ranking O
SVM O
and O
RankBoost B-KEY
train B-KEY
ranking I-KEY
models I-KEY
by O
minimizing O
classification O
errors O
on O
instance O
pairs O
. O
To O
deal O
with O
the O
problem O
, O
we O
propose O
a O
novel B-KEY
learning I-KEY
algorithm I-KEY
within O
the O
framework O
of O
boosting B-KEY
, O
which O
can O
minimize O
a O
loss O
function O
directly O
defined O
on O
the O
performance O
measures O
. O
Our O
algorithm O
, O
referred O
to O
as O
AdaRank O
, O
repeatedly O
constructs O
` O
weak B-KEY
rankers I-KEY
' O
on O
the O
basis O
of O
re-weighted B-KEY
training I-KEY
data I-KEY
and O
finally O
linearly O
combines O
the O
weak B-KEY
rankers I-KEY
for O
making O
ranking O
predictions O
. O
We O
prove O
that O
the O
training B-KEY
process I-KEY
of O
AdaRank O
is O
exactly O
that O
of O
enhancing O
the O
performance O
measure O
used O
. O
Experimental O
results O
on O
four O
benchmark O
datasets O
show O
that O
AdaRank O
significantly O
outperforms O
the O
baseline O
methods O
of O
BM25 O
, O
Ranking O
SVM O
, O
and O
RankBoost B-KEY
. O
Knowledge-intensive O
Conceptual O
Retrieval O
and O
Passage B-KEY
Extraction I-KEY
of O
Biomedical O
Literature O
ABSTRACT O
This O
paper O
presents O
a O
study O
of O
incorporating O
domain-specific B-KEY
knowledge I-KEY
-LRB- O
i.e. O
, O
information O
about O
concepts O
and O
relationships O
between O
concepts O
in O
a O
certain O
domain O
-RRB- O
in O
an O
information O
retrieval O
-LRB- O
IR O
-RRB- O
system O
to O
improve O
its O
effectiveness O
in O
retrieving O
biomedical O
literature O
. O
The O
effects O
of O
different O
types O
of O
domain-specific B-KEY
knowledge I-KEY
in O
performance O
contribution O
are O
examined O
. O
Based O
on O
the O
TREC O
platform O
, O
we O
show O
that O
appropriate O
use O
of O
domainspecific O
knowledge O
in O
a O
proposed O
conceptual O
retrieval B-KEY
model I-KEY
yields O
about O
23 O
% O
improvement O
over O
the O
best O
reported O
result O
in O
passage O
retrieval O
in O
the O
Genomics O
Track O
of O
TREC O
2006 O
. O
On O
Cheating B-KEY
in O
Sealed-Bid O
Auctions B-KEY
Motivated O
by O
the O
rise O
of O
online O
auctions B-KEY
and O
their O
relative O
lack O
of O
security O
, O
this O
paper O
analyzes O
two O
forms O
of O
cheating B-KEY
in O
sealed-bid O
auctions B-KEY
. O
The O
first O
type O
of O
cheating B-KEY
we O
consider O
occurs O
when O
the O
seller B-KEY
spies O
on O
the O
bids O
of O
a O
second-price O
auction B-KEY
and O
then O
inserts O
a O
fake O
bid O
in O
order O
to O
increase O
the O
payment B-KEY
of O
the O
winning O
bidder O
. O
In O
the O
second O
type O
, O
a O
bidder O
cheats B-KEY
in O
a O
first-price O
auction B-KEY
by O
examining O
the O
competing O
bids O
before O
deciding O
on O
his O
own O
bid O
. O
In O
both O
cases B-KEY
, O
we O
derive O
equilibrium O
strategies O
when O
bidders O
are O
aware O
of O
the O
possibility B-KEY
of O
cheating B-KEY
. O
These O
results O
provide O
insights O
into O
sealedbid O
auctions B-KEY
even O
in O
the O
absence O
of O
cheating B-KEY
, O
including O
some O
counterintuitive O
results O
on O
the O
effects O
of O
overbidding O
in O
a O
first-price O
auction B-KEY
. O
Selfish O
Caching B-KEY
in O
Distributed B-KEY
Systems I-KEY
: O
A O
Game-Theoretic O
Analysis O
ABSTRACT O
We O
analyze O
replication O
of O
resources O
by O
server O
nodes O
that O
act O
selfishly O
, O
using O
a O
game-theoretic B-KEY
approach I-KEY
. O
We O
refer O
to O
this O
as O
the O
selfish O
caching B-KEY
problem O
. O
In O
our O
model O
, O
nodes O
incur O
either O
cost O
for O
replicating O
resources O
or O
cost O
for O
access O
to O
a O
remote B-KEY
replica I-KEY
. O
We O
show O
the O
existence O
of O
pure O
strategy O
Nash O
equilibria O
and O
investigate O
the O
price B-KEY
of I-KEY
anarchy I-KEY
, O
which O
is O
the O
relative O
cost O
of O
the O
lack O
of O
coordination O
. O
The O
price B-KEY
of I-KEY
anarchy I-KEY
can O
be O
high O
due O
to O
undersupply O
problems O
, O
but O
with O
certain O
network B-KEY
topologies I-KEY
it O
has O
better O
bounds O
. O
With O
a O
payment O
scheme O
the O
game O
can O
always O
implement O
the O
social O
optimum O
in O
the O
best O
case O
by O
giving O
servers O
incentive O
to O
replicate O
. O
On O
Opportunistic O
Techniques O
for O
Solving O
Decentralized B-KEY
Markov I-KEY
Decision I-KEY
Processes I-KEY
with O
Temporal B-KEY
Constraints I-KEY
ABSTRACT O
Decentralized B-KEY
Markov I-KEY
Decision I-KEY
Processes I-KEY
-LRB- O
DEC-MDPs O
-RRB- O
are O
a O
popular O
model O
of O
agent-coordination B-KEY
problems I-KEY
in O
domains O
with O
uncertainty O
and O
time O
constraints O
but O
very O
difficult O
to O
solve O
. O
In O
this O
paper O
, O
we O
improve O
a O
state-of-the-art O
heuristic O
solution O
method O
for O
DEC-MDPs O
, O
called O
OC-DEC-MDP O
, O
that O
has O
recently O
been O
shown O
to O
scale O
up O
to O
larger O
DEC-MDPs O
. O
Our O
heuristic O
solution O
method O
, O
called O
Value B-KEY
Function I-KEY
Propagation I-KEY
-LRB- O
VFP O
-RRB- O
, O
combines O
two O
orthogonal O
improvements O
of O
OC-DEC-MDP O
. O
First O
, O
it O
speeds O
up O
OC-DECMDP O
by O
an O
order O
of O
magnitude O
by O
maintaining O
and O
manipulating O
a O
value O
function O
for O
each O
state O
-LRB- O
as O
a O
function O
of O
time O
-RRB- O
rather O
than O
a O
separate O
value O
for O
each O
pair O
of O
sate O
and O
time O
interval O
. O
Furthermore O
, O
it O
achieves O
better O
solution O
qualities O
than O
OC-DEC-MDP O
because O
, O
as O
our O
analytical O
results O
show O
, O
it O
does O
not O
overestimate O
the O
expected O
total O
reward O
like O
OC-DEC O
- O
MDP O
. O
We O
test O
both O
improvements O
independently O
in O
a O
crisis-management O
domain O
as O
well O
as O
for O
other O
types O
of O
domains O
. O
Our O
experimental O
results O
demonstrate O
a O
significant O
speedup O
of O
VFP O
over O
OC-DEC-MDP O
as O
well O
as O
higher O
solution O
qualities O
in O
a O
variety O
of O
situations O
. O
Approximate B-KEY
and O
Online O
Multi-Issue O
Negotiation B-KEY
ABSTRACT O
This O
paper O
analyzes O
bilateral O
multi-issue O
negotiation B-KEY
between O
selfinterested O
autonomous O
agents O
. O
The O
agents O
have O
time B-KEY
constraints I-KEY
in O
the O
form O
of O
both O
deadlines O
and O
discount O
factors O
. O
There O
are O
m O
> O
1 O
issues O
for O
negotiation B-KEY
where O
each O
issue O
is O
viewed O
as O
a O
pie O
of O
size O
one O
. O
The O
issues O
are O
`` O
indivisible O
'' O
-LRB- O
i.e. O
, O
individual O
issues O
can O
not O
be O
split O
between O
the O
parties O
; O
each O
issue O
must O
be O
allocated O
in O
its O
entirety O
to O
either O
agent O
-RRB- O
. O
Here O
different O
agents O
value O
different O
issues O
differently O
. O
Thus O
, O
the O
problem O
is O
for O
the O
agents O
to O
decide O
how O
to O
allocate O
the O
issues O
between O
themselves O
so O
as O
to O
maximize O
their O
individual O
utilities O
. O
For O
such O
negotiations B-KEY
, O
we O
first O
obtain O
the O
equilibrium B-KEY
strategies B-KEY
for O
the O
case O
where O
the O
issues O
for O
negotiation B-KEY
are O
known O
a O
priori O
to O
the O
parties O
. O
Then O
, O
we O
analyse O
their O
time O
complexity O
and O
show O
that O
finding O
the O
equilibrium B-KEY
offers O
is O
an O
NP-hard O
problem O
, O
even O
in O
a O
complete O
information O
setting O
. O
In O
order O
to O
overcome O
this O
computational O
complexity O
, O
we O
then O
present O
negotiation B-KEY
strategies B-KEY
that O
are O
approximately B-KEY
optimal O
but O
computationally O
efficient O
, O
and O
show O
that O
they O
form O
an O
equilibrium B-KEY
. O
We O
also O
analyze O
the O
relative B-KEY
error I-KEY
-LRB- O
i.e. O
, O
the O
difference O
between O
the O
true O
optimum O
and O
the O
approximate B-KEY
-RRB- O
. O
The O
time O
complexity O
of O
the O
approximate B-KEY
equilibrium B-KEY
strategies B-KEY
is O
O O
-LRB- O
nm O
/ O
~ O
2 O
-RRB- O
where O
n O
is O
the O
negotiation B-KEY
deadline O
and O
~ O
the O
relative B-KEY
error I-KEY
. O
Finally O
, O
we O
extend O
the O
analysis O
to O
online O
negotiation B-KEY
where O
different O
issues O
become O
available O
at O
different O
time O
points O
and O
the O
agents O
are O
uncertain O
about O
their O
valuations O
for O
these O
issues O
. O
Specifically O
, O
we O
show O
that O
an O
approximate B-KEY
equilibrium B-KEY
exists O
for O
online O
negotiation B-KEY
and O
show O
that O
the O
expected O
difference O
between O
the O
optimum O
and O
the O
approximate B-KEY
is O
O O
-LRB- O
√ O
m O
-RRB- O
. O
These O
approximate B-KEY
strategies B-KEY
also O
have O
polynomial O
time O
complexity O
. O
CenWits O
: O
A O
Sensor-Based O
Loosely O
Coupled O
Search B-KEY
and I-KEY
Rescue I-KEY
System O
Using O
Witnesses B-KEY
University O
of O
Colorado O
, O
Campus O
Box O
0430 O
Boulder O
, O
CO O
80309-0430 O
ABSTRACT O
This O
paper O
describes O
the O
design O
, O
implementation O
and O
evaluation O
of O
a O
search B-KEY
and I-KEY
rescue I-KEY
system O
called O
CenWits O
. O
CenWits O
uses O
several O
small O
, O
commonly-available O
RF-based O
sensors O
, O
and O
a O
small O
number O
of O
storage O
and O
processing O
devices O
. O
It O
is O
designed O
for O
search B-KEY
and I-KEY
rescue I-KEY
of O
people O
in O
emergency B-KEY
situations I-KEY
in O
wilderness O
areas O
. O
A O
key O
feature O
of O
CenWits O
is O
that O
it O
does O
not O
require O
a O
continuously O
connected O
sensor B-KEY
network I-KEY
for O
its O
operation O
. O
It O
is O
designed O
for O
an O
intermittently O
connected B-KEY
network I-KEY
that O
provides O
only O
occasional O
connectivity O
. O
It O
makes O
a O
judicious O
use O
of O
the O
combined O
storage O
capability O
of O
sensors O
to O
filter O
, O
organize O
and O
store O
important O
information O
, O
combined O
battery O
power O
of O
sensors O
to O
ensure O
that O
the O
system O
remains O
operational O
for O
longer O
time O
periods O
, O
and O
intermittent B-KEY
network I-KEY
connectivity I-KEY
to O
propagate O
information O
to O
a O
processing O
center O
. O
A O
prototype O
of O
CenWits O
has O
been O
implemented O
using O
Berkeley O
Mica2 O
motes O
. O
The O
paper O
describes O
this O
implementation O
and O
reports O
on O
the O
performance O
measured O
from O
it O
. O
Handling O
Locations O
in O
Search B-KEY
Engine I-KEY
Queries I-KEY
ABSTRACT O
This O
paper O
proposes O
simple O
techniques O
for O
handling O
place B-KEY
references I-KEY
in O
search B-KEY
engine I-KEY
queries I-KEY
, O
an O
important O
aspect O
of O
geographical B-KEY
information I-KEY
retrieval I-KEY
. O
We O
address O
not O
only O
the O
detection O
, O
but O
also O
the O
disambiguation O
of O
place B-KEY
references I-KEY
, O
by O
matching O
them O
explicitly O
with O
concepts O
at O
an O
ontology O
. O
Moreover O
, O
when O
a O
query O
does O
not O
reference O
any O
locations O
, O
we O
propose O
to O
use O
information O
from O
documents O
matching O
the O
query O
, O
exploiting O
geographic O
scopes O
previously O
assigned O
to O
these O
documents O
. O
Evaluation O
experiments O
, O
using O
topics O
from O
CLEF O
campaigns O
and O
logs O
from O
real O
search B-KEY
engine I-KEY
queries I-KEY
, O
show O
the O
effectiveness O
of O
the O
proposed O
approaches O
. O
GUESS O
: O
Gossiping O
Updates O
for O
Efficient O
Spectrum B-KEY
Sensing I-KEY
ABSTRACT O
Wireless O
radios O
of O
the O
future O
will O
likely O
be O
frequency-agile O
, O
that O
is O
, O
supporting O
opportunistic O
and O
adaptive O
use O
of O
the O
RF B-KEY
spectrum I-KEY
. O
Such O
radios O
must O
coordinate O
with O
each O
other O
to O
build O
an O
accurate O
and O
consistent O
map O
of O
spectral O
utilization O
in O
their O
surroundings O
. O
We O
focus O
on O
the O
problem O
of O
sharing O
RF B-KEY
spectrum I-KEY
data O
among O
a O
collection O
of O
wireless O
devices O
. O
The O
inherent O
requirements O
of O
such O
data O
and O
the O
time-granularity O
at O
which O
it O
must O
be O
collected O
makes O
this O
problem O
both O
interesting O
and O
technically O
challenging O
. O
We O
propose O
GUESS O
, O
a O
novel O
incremental O
gossiping O
approach O
to O
coordinated O
spectral O
sensing O
. O
It O
-LRB- O
1 O
-RRB- O
reduces O
protocol O
overhead O
by O
limiting O
the O
amount O
of O
information O
exchanged O
between O
participating O
nodes O
, O
-LRB- O
2 O
-RRB- O
is O
resilient O
to O
network O
alterations O
, O
due O
to O
node O
movement O
or O
node O
failures O
, O
and O
-LRB- O
3 O
-RRB- O
allows O
exponentially-fast O
information O
convergence O
. O
We O
outline O
an O
initial O
solution O
incorporating O
these O
ideas O
and O
also O
show O
how O
our O
approach O
reduces O
network O
overhead O
by O
up O
to O
a O
factor O
of O
2.4 O
and O
results O
in O
up O
to O
2.7 O
times O
faster O
information O
convergence O
than O
alternative O
approaches O
. O
Heuristics-Based O
Scheduling B-KEY
of O
Composite O
Web B-KEY
Service I-KEY
Workloads O
ABSTRACT O
Web B-KEY
services I-KEY
can O
be O
aggregated O
to O
create O
composite O
workflows O
that O
provide O
streamlined B-KEY
functionality I-KEY
for O
human O
users O
or O
other O
systems O
. O
Although O
industry O
standards O
and O
recent O
research O
have O
sought O
to O
define O
best O
practices O
and O
to O
improve O
end-to-end B-KEY
workflow I-KEY
composition I-KEY
, O
one O
area O
that O
has O
not O
fully O
been O
explored O
is O
the O
scheduling B-KEY
of O
a O
workflow O
's O
web B-KEY
service I-KEY
requests O
to O
actual O
service O
provisioning O
in O
a O
multi-tiered O
, O
multi-organisation O
environment O
. O
This O
issue O
is O
relevant O
to O
modern O
business O
scenarios O
where O
business O
processes O
within O
a O
workflow O
must O
complete O
within O
QoS-defined O
limits O
. O
Because O
these O
business O
processes O
are O
web B-KEY
service I-KEY
consumers O
, O
service B-KEY
requests I-KEY
must O
be O
mapped O
and O
scheduled B-KEY
across O
multiple O
web B-KEY
service I-KEY
providers O
, O
each O
with O
its O
own O
negotiated O
service O
level O
agreement O
. O
In O
this O
paper O
we O
provide O
heuristics B-KEY
for O
scheduling B-KEY
service O
requests O
from O
multiple O
business O
process O
workflows O
to O
web O
service O
providers O
such O
that O
a O
business O
value O
metric O
across O
all O
workflows O
is O
maximised O
. O
We O
show O
that O
a O
genetic O
search O
algorithm O
is O
appropriate O
to O
perform O
this O
scheduling B-KEY
, O
and O
through O
experimentation O
we O
show O
that O
our O
algorithm O
scales O
well O
up O
to O
a O
thousand O
workflows O
and O
produces O
better O
mappings O
than O
traditional O
approaches O
. O
Implicit B-KEY
User I-KEY
Modeling I-KEY
for O
Personalized O
Search O
ABSTRACT O
Information B-KEY
retrieval I-KEY
systems I-KEY
-LRB- O
e.g. O
, O
web O
search O
engines O
-RRB- O
are O
critical O
for O
overcoming O
information O
overload O
. O
A O
major O
deficiency O
of O
existing O
retrieval O
systems O
is O
that O
they O
generally O
lack O
user B-KEY
modeling I-KEY
and O
are O
not O
adaptive O
to O
individual O
users O
, O
resulting O
in O
inherently O
non-optimal O
retrieval B-KEY
performance I-KEY
. O
For O
example O
, O
a O
tourist O
and O
a O
programmer O
may O
use O
the O
same O
word O
`` O
java O
'' O
to O
search O
for O
different O
information O
, O
but O
the O
current O
search O
systems O
would O
return O
the O
same O
results O
. O
In O
this O
paper O
, O
we O
study O
how O
to O
infer O
a O
user O
's O
interest O
from O
the O
user O
's O
search O
context O
and O
use O
the O
inferred O
implicit B-KEY
user I-KEY
model I-KEY
for O
personalized O
search O
. O
We O
present O
a O
decision O
theoretic O
framework O
and O
develop O
techniques O
for O
implicit B-KEY
user I-KEY
modeling I-KEY
in O
information O
retrieval O
. O
We O
develop O
an O
intelligent O
client-side O
web O
search O
agent O
-LRB- O
UCAIR O
-RRB- O
that O
can O
perform O
eager O
implicit B-KEY
feedback I-KEY
, O
e.g. O
, O
query B-KEY
expansion I-KEY
based O
on O
previous O
queries O
and O
immediate O
result O
reranking O
based O
on O
clickthrough O
information O
. O
Experiments O
on O
web O
search O
show O
that O
our O
search O
agent O
can O
improve O
search B-KEY
accuracy I-KEY
over O
the O
popular O
Google O
search O
engine O
. O
Composition O
of O
a O
DIDS O
by O
Integrating O
Heterogeneous O
IDSs O
on O
Grids B-KEY
ABSTRACT O
This O
paper O
considers O
the O
composition O
of O
a O
DIDS O
-LRB- O
Distributed B-KEY
Intrusion I-KEY
Detection I-KEY
System I-KEY
-RRB- O
by O
integrating O
heterogeneous O
IDSs O
-LRB- O
Intrusion O
Detection O
Systems O
-RRB- O
. O
A O
Grid B-KEY
middleware O
is O
used O
for O
this O
integration O
. O
In O
addition O
, O
an O
architecture O
for O
this O
integration O
is O
proposed O
and O
validated O
through O
simulation O
. O
Distributed O
Agent-Based O
Air O
Traffic B-KEY
Flow I-KEY
Management O
ABSTRACT O
Air O
traffic B-KEY
flow I-KEY
management O
is O
one O
of O
the O
fundamental O
challenges O
facing O
the O
Federal O
Aviation O
Administration O
-LRB- O
FAA O
-RRB- O
today O
. O
The O
FAA O
estimates O
that O
in O
2005 O
alone O
, O
there O
were O
over O
322,000 O
hours O
of O
delays O
at O
a O
cost O
to O
the O
industry O
in O
excess O
of O
three O
billion O
dollars O
. O
Finding O
reliable O
and O
adaptive O
solutions O
to O
the O
flow O
management O
problem O
is O
of O
paramount O
importance O
if O
the O
Next O
Generation O
Air O
Transportation O
Systems O
are O
to O
achieve O
the O
stated O
goal O
of O
accommodating O
three O
times O
the O
current O
traffic O
volume O
. O
This O
problem O
is O
particularly O
complex O
as O
it O
requires O
the O
integration O
and/or O
coordination O
of O
many O
factors O
including O
: O
new O
data O
-LRB- O
e.g. O
, O
changing O
weather O
info O
-RRB- O
, O
potentially O
conflicting O
priorities O
-LRB- O
e.g. O
, O
different O
airlines O
-RRB- O
, O
limited O
resources O
-LRB- O
e.g. O
, O
air B-KEY
traffic I-KEY
controllers I-KEY
-RRB- O
and O
very O
heavy O
traffic O
volume O
-LRB- O
e.g. O
, O
over O
40,000 O
flights O
over O
the O
US O
airspace O
-RRB- O
. O
In O
this O
paper O
we O
use O
FACET O
-- O
an O
air O
traffic B-KEY
flow I-KEY
simulator O
developed O
at O
NASA O
and O
used O
extensively O
by O
the O
FAA O
and O
industry O
-- O
to O
test O
a O
multi-agent O
algorithm O
for O
traffic B-KEY
flow I-KEY
management O
. O
An O
agent O
is O
associated O
with O
a O
fix O
-LRB- O
a O
specific O
location O
in O
2D O
space O
-RRB- O
and O
its O
action O
consists O
of O
setting O
the O
separation O
required O
among O
the O
airplanes O
going O
though O
that O
fix O
. O
Agents O
use O
reinforcement B-KEY
learning I-KEY
to O
set O
this O
separation O
and O
their O
actions O
speed O
up O
or O
slow O
down O
traffic O
to O
manage O
congestion B-KEY
. O
Our O
FACET O
based O
results O
show O
that O
agents O
receiving O
personalized O
rewards O
reduce O
congestion B-KEY
by O
up O
to O
45 O
% O
over O
agents O
receiving O
a O
global O
reward O
and O
by O
up O
to O
67 O
% O
over O
a O
current O
industry O
approach O
-LRB- O
Monte O
Carlo O
estimation O
-RRB- O
. O
An O
Efficient O
Heuristic B-KEY
Approach I-KEY
for O
Security O
Against O
Multiple O
Adversaries O
ABSTRACT O
In O
adversarial B-KEY
multiagent I-KEY
domains I-KEY
, O
security O
, O
commonly O
defined O
as O
the O
ability O
to O
deal O
with O
intentional O
threats O
from O
other O
agents O
, O
is O
a O
critical O
issue O
. O
This O
paper O
focuses O
on O
domains O
where O
these O
threats O
come O
from O
unknown O
adversaries O
. O
These O
domains O
can O
be O
modeled O
as O
Bayesian B-KEY
games I-KEY
; O
much O
work O
has O
been O
done O
on O
finding O
equilibria O
for O
such O
games O
. O
However O
, O
it O
is O
often O
the O
case O
in O
multiagent O
security O
domains O
that O
one O
agent O
can O
commit O
to O
a O
mixed O
strategy O
which O
its O
adversaries O
observe O
before O
choosing O
their O
own O
strategies O
. O
In O
this O
case O
, O
the O
agent O
can O
maximize O
reward O
by O
finding O
an O
optimal O
strategy O
, O
without O
requiring O
equilibrium O
. O
Previous O
work O
has O
shown O
this O
problem O
of O
optimal O
strategy O
selection O
to O
be O
NP-hard B-KEY
. O
Therefore O
, O
we O
present O
a O
heuristic O
called O
ASAP O
, O
with O
three O
key O
advantages O
to O
address O
the O
problem O
. O
First O
, O
ASAP O
searches O
for O
the O
highest-reward O
strategy O
, O
rather O
than O
a O
Bayes-Nash O
equilibrium O
, O
allowing O
it O
to O
find O
feasible O
strategies O
that O
exploit O
the O
natural O
first-mover O
advantage O
of O
the O
game O
. O
Second O
, O
it O
provides O
strategies O
which O
are O
simple O
to O
understand O
, O
represent O
, O
and O
implement O
. O
Third O
, O
it O
operates O
directly O
on O
the O
compact O
, O
Bayesian B-KEY
game I-KEY
representation O
, O
without O
requiring O
conversion O
to O
normal O
form O
. O
We O
provide O
an O
efficient O
Mixed O
Integer O
Linear O
Program O
-LRB- O
MILP O
-RRB- O
implementation O
for O
ASAP O
, O
along O
with O
experimental O
results O
illustrating O
significant O
speedups O
and O
higher O
rewards O
over O
other O
approaches O
. O
-LRB- O
In O
-RRB- O
Stability O
Properties O
of O
Limit O
Order O
Dynamics O
ABSTRACT O
We O
study O
the O
stability O
properties O
of O
the O
dynamics O
of O
the O
standard O
continuous O
limit-order O
mechanism O
that O
is O
used O
in O
modern B-KEY
equity I-KEY
markets I-KEY
. O
We O
ask O
whether O
such O
mechanisms O
are O
susceptible O
to O
`` O
butterfly O
effects O
'' O
-- O
the O
infliction O
of O
large O
changes O
on O
common O
measures O
of O
market O
activity O
by O
only O
small O
perturbations O
of O
the O
order O
sequence O
. O
We O
show O
that O
the O
answer O
depends O
strongly O
on O
whether O
the O
market O
consists O
of O
`` O
absolute O
'' O
traders O
-LRB- O
who O
determine O
their O
prices O
independent O
of O
the O
current O
order O
book O
state O
-RRB- O
or O
`` O
relative O
'' O
traders O
-LRB- O
who O
determine O
their O
prices O
relative O
to O
the O
current O
bid B-KEY
and O
ask O
-RRB- O
. O
We O
prove O
that O
while O
the O
absolute B-KEY
trader I-KEY
model I-KEY
enjoys O
provably O
strong O
stability O
properties O
, O
the O
relative B-KEY
trader I-KEY
model I-KEY
is O
vulnerable O
to O
great O
instability O
. O
Our O
theoretical O
results O
are O
supported O
by O
large-scale O
experiments O
using O
limit O
order O
data O
from O
INET O
, O
a O
large O
electronic O
exchange O
for O
NASDAQ O
stocks O
. O
Congestion B-KEY
Games I-KEY
with O
Load-Dependent B-KEY
Failures I-KEY
: O
Identical B-KEY
Resources I-KEY
ABSTRACT O
We O
define O
a O
new O
class O
of O
games O
, O
congestion B-KEY
games I-KEY
with O
loaddependent O
failures O
-LRB- O
CGLFs O
-RRB- O
, O
which O
generalizes O
the O
well-known O
class O
of O
congestion B-KEY
games I-KEY
, O
by O
incorporating O
the O
issue O
of O
resource O
failures O
into O
congestion B-KEY
games I-KEY
. O
In O
a O
CGLF O
, O
agents O
share O
a O
common O
set O
of O
resources O
, O
where O
each O
resource O
has O
a O
cost O
and O
a O
probability O
of O
failure O
. O
Each O
agent O
chooses O
a O
subset O
of O
the O
resources O
for O
the O
execution O
of O
his O
task O
, O
in O
order O
to O
maximize O
his O
own O
utility O
. O
The O
utility O
of O
an O
agent O
is O
the O
difference O
between O
his O
benefit O
from O
successful O
task O
completion O
and O
the O
sum O
of O
the O
costs O
over O
the O
resources O
he O
uses O
. O
CGLFs O
possess O
two O
novel O
features O
. O
It O
is O
the O
first O
model O
to O
incorporate O
failures O
into O
congestion O
settings O
, O
which O
results O
in O
a O
strict O
generalization O
of O
congestion B-KEY
games I-KEY
. O
In O
addition O
, O
it O
is O
the O
first O
model O
to O
consider O
load-dependent B-KEY
failures I-KEY
in O
such O
framework O
, O
where O
the O
failure B-KEY
probability I-KEY
of O
each O
resource O
depends O
on O
the O
number O
of O
agents O
selecting O
this O
resource O
. O
Although O
, O
as O
we O
show O
, O
CGLFs O
do O
not O
admit O
a O
potential B-KEY
function I-KEY
, O
and O
in O
general O
do O
not O
have O
a O
pure B-KEY
strategy I-KEY
Nash I-KEY
equilibrium I-KEY
, O
our O
main O
theorem O
proves O
the O
existence O
of O
a O
pure O
strategy O
Nash O
equilibrium O
in O
every O
CGLF O
with O
identical O
resources O
and O
nondecreasing O
cost O
functions O
. O
An O
Agent-Based O
Approach O
for O
Privacy-Preserving O
Recommender B-KEY
Systems I-KEY
ABSTRACT O
Recommender B-KEY
Systems I-KEY
are O
used O
in O
various O
domains O
to O
generate O
personalized O
information O
based O
on O
personal O
user O
data O
. O
The O
ability O
to O
preserve O
the O
privacy B-KEY
of O
all O
participants O
is O
an O
essential O
requirement O
of O
the O
underlying O
Information B-KEY
Filtering I-KEY
architectures O
, O
because O
the O
deployed O
Recommender B-KEY
Systems I-KEY
have O
to O
be O
accepted O
by O
privacy-aware O
users O
as O
well O
as O
information O
and O
service O
providers O
. O
Existing O
approaches O
neglect O
to O
address O
privacy B-KEY
in O
this O
multilateral O
way O
. O
We O
have O
developed O
an O
approach O
for O
privacy-preserving O
Recommender B-KEY
Systems I-KEY
based O
on O
Multi-Agent O
System O
technology O
which O
enables O
applications O
to O
generate O
recommendations O
via O
various O
filtering O
techniques O
while O
preserving O
the O
privacy B-KEY
of O
all O
participants O
. O
We O
describe O
the O
main O
modules O
of O
our O
solution O
as O
well O
as O
an O
application O
we O
have O
implemented O
based O
on O
this O
approach O
. O
DiffusionRank B-KEY
: O
A O
Possible O
Penicillin O
for O
Web B-KEY
Spamming I-KEY
ABSTRACT O
While O
the O
PageRank B-KEY
algorithm O
has O
proven O
to O
be O
very O
effective O
for O
ranking B-KEY
Web O
pages O
, O
the O
rank B-KEY
scores O
of O
Web O
pages O
can O
be O
manipulated O
. O
To O
handle O
the O
manipulation O
problem O
and O
to O
cast O
a O
new O
insight O
on O
the O
Web O
structure O
, O
we O
propose O
a O
ranking B-KEY
algorithm O
called O
DiffusionRank B-KEY
. O
DiffusionRank B-KEY
is O
motivated O
by O
the O
heat O
diffusion O
phenomena O
, O
which O
can O
be O
connected O
to O
Web O
ranking B-KEY
because O
the O
activities O
flow O
on O
the O
Web O
can O
be O
imagined O
as O
heat O
flow O
, O
the O
link O
from O
a O
page O
to O
another O
can O
be O
treated O
as O
the O
pipe O
of O
an O
air-conditioner O
, O
and O
heat O
flow O
can O
embody O
the O
structure O
of O
the O
underlying O
Web B-KEY
graph I-KEY
. O
Theoretically O
we O
show O
that O
DiffusionRank B-KEY
can O
serve O
as O
a O
generalization O
of O
PageRank B-KEY
when O
the O
heat O
diffusion O
coefficient O
- O
y O
tends O
to O
infinity O
. O
In O
such O
a O
case O
1 O
/ O
- O
y O
= O
0 O
, O
DiffusionRank B-KEY
-LRB- O
PageRank B-KEY
-RRB- O
has O
low O
ability O
of O
anti-manipulation O
. O
When O
- O
y O
= O
0 O
, O
DiffusionRank B-KEY
obtains O
the O
highest O
ability O
of O
anti-manipulation O
, O
but O
in O
such O
a O
case O
, O
the O
web O
structure O
is O
completely O
ignored O
. O
Consequently O
, O
- O
y O
is O
an O
interesting O
factor O
that O
can O
control O
the O
balance O
between O
the O
ability O
of O
preserving O
the O
original O
Web O
and O
the O
ability O
of O
reducing O
the O
effect O
of O
manipulation O
. O
It O
is O
found O
empirically O
that O
, O
when O
- O
y O
= O
1 O
, O
DiffusionRank B-KEY
has O
a O
Penicillin-like O
effect O
on O
the O
link O
manipulation O
. O
Moreover O
, O
DiffusionRank B-KEY
can O
be O
employed O
to O
find O
group-to-group B-KEY
relations I-KEY
on O
the O
Web O
, O
to O
divide O
the O
Web B-KEY
graph I-KEY
into O
several O
parts O
, O
and O
to O
find O
link B-KEY
communities I-KEY
. O
Experimental O
results O
show O
that O
the O
DiffusionRank B-KEY
algorithm O
achieves O
the O
above O
mentioned O
advantages O
as O
expected O
. O
StarDust O
: O
A O
Flexible O
Architecture O
for O
Passive O
Localization B-KEY
in O
Wireless B-KEY
Sensor I-KEY
Networks I-KEY
* O
Abstract O
The O
problem O
of O
localization B-KEY
in O
wireless B-KEY
sensor I-KEY
networks I-KEY
where O
nodes O
do O
not O
use O
ranging B-KEY
hardware O
, O
remains O
a O
challenging O
problem O
, O
when O
considering O
the O
required O
location O
accuracy O
, O
energy O
expenditure O
and O
the O
duration O
of O
the O
localization B-KEY
phase O
. O
In O
this O
paper O
we O
propose O
a O
framework O
, O
called O
StarDust O
, O
for O
wireless B-KEY
sensor I-KEY
network I-KEY
localization B-KEY
based O
on O
passive O
optical O
components O
. O
In O
the O
StarDust O
framework O
, O
sensor B-KEY
nodes I-KEY
are O
equipped O
with O
optical O
retro-reflectors O
. O
An O
aerial O
device O
projects O
light O
towards O
the O
deployed O
sensor O
network O
, O
and O
records O
an O
image O
of O
the O
reflected O
light O
. O
An O
image B-KEY
processing I-KEY
algorithm O
is O
developed O
for O
obtaining O
the O
locations O
of O
sensor B-KEY
nodes I-KEY
. O
For O
matching O
a O
node O
ID O
to O
a O
location O
we O
propose O
a O
constraint-based O
label O
relaxation O
algorithm O
. O
We O
propose O
and O
develop O
localization B-KEY
techniques O
based O
on O
four O
types O
of O
constraints O
: O
node O
color O
, O
neighbor O
information O
, O
deployment O
time O
for O
a O
node O
and O
deployment O
location O
for O
a O
node O
. O
We O
evaluate O
the O
performance B-KEY
of O
a O
localization B-KEY
system O
based O
on O
our O
framework O
by O
localizing B-KEY
a O
network O
of O
26 O
sensor B-KEY
nodes I-KEY
deployed O
in O
a O
120 O
x O
60ft2 O
area O
. O
The O
localization B-KEY
accuracy O
ranges B-KEY
from O
2ft O
to O
5 O
ft O
while O
the O
localization B-KEY
time O
ranges B-KEY
from O
10 O
milliseconds O
to O
2 O
minutes O
. O
A O
Framework O
for O
Agent-Based O
Distributed O
Machine O
Learning O
and O
Data O
Mining O
ABSTRACT O
This O
paper O
proposes O
a O
framework O
for O
agent-based O
distributed O
machine O
learning O
and O
data O
mining O
based O
on O
-LRB- O
i O
-RRB- O
the O
exchange O
of O
meta-level O
descriptions O
of O
individual O
learning O
processes O
among O
agents O
and O
-LRB- O
ii O
-RRB- O
online O
reasoning O
about O
learning O
success O
and O
learning O
progress O
by O
learning O
agents O
. O
We O
present O
an O
abstract O
architecture O
that O
enables O
agents B-KEY
to O
exchange O
models O
of O
their O
local O
learning O
processes O
and O
introduces O
a O
number O
of O
different O
methods O
for O
integrating O
these O
processes O
. O
This O
allows O
us O
to O
apply O
existing O
agent B-KEY
interaction O
mechanisms O
to O
distributed B-KEY
machine I-KEY
learning I-KEY
tasks O
, O
thus O
leveraging O
the O
powerful O
coordination O
methods O
available O
in O
agent-based O
computing O
, O
and O
enables O
agents O
to O
engage O
in O
meta-reasoning O
about O
their O
own O
learning O
decisions O
. O
We O
apply O
this O
architecture O
to O
a O
real-world O
distributed B-KEY
clustering I-KEY
application I-KEY
to O
illustrate O
how O
the O
conceptual O
framework O
can O
be O
used O
in O
practical O
systems O
in O
which O
different O
learners O
may O
be O
using O
different O
datasets O
, O
hypotheses O
and O
learning O
algorithms O
. O
We O
report O
on O
experimental O
results O
obtained O
using O
this O
system O
, O
review O
related O
work O
on O
the O
subject O
, O
and O
discuss O
potential O
future O
extensions O
to O
the O
framework O
. O
Hidden-Action O
in O
Multi-Hop B-KEY
Routing B-KEY
ABSTRACT O
In O
multi-hop B-KEY
networks O
, O
the O
actions O
taken O
by O
individual O
intermediate O
nodes O
are O
typically O
hidden O
from O
the O
communicating O
endpoints O
; O
all O
the O
endpoints O
can O
observe O
is O
whether O
or O
not O
the O
end-to-end O
transmission O
was O
successful O
. O
Therefore O
, O
in O
the O
absence O
of O
incentives B-KEY
to O
the O
contrary O
, O
rational O
-LRB- O
i.e. O
, O
selfish O
-RRB- O
intermediate B-KEY
nodes I-KEY
may O
choose O
to O
forward O
packets O
at O
a O
low O
priority B-KEY
or O
simply O
not O
forward O
packets O
at O
all O
. O
Using O
a O
principal-agent O
model O
, O
we O
show O
how O
the O
hidden-action O
problem O
can O
be O
overcome O
through O
appropriate O
design O
of O
contracts B-KEY
, O
in O
both O
the O
direct O
-LRB- O
the O
endpoints B-KEY
contract B-KEY
with O
each O
individual O
router O
-RRB- O
and O
recursive O
-LRB- O
each O
router O
contracts B-KEY
with O
the O
next O
downstream O
router O
-RRB- O
cases O
. O
We O
further O
demonstrate O
that O
per-hop O
monitoring O
does O
not O
necessarily O
improve O
the O
utility O
of O
the O
principal O
or O
the O
social O
welfare O
in O
the O
system O
. O
In O
addition O
, O
we O
generalize O
existing O
mechanisms B-KEY
that O
deal O
with O
hidden-information O
to O
handle O
scenarios O
involving O
both O
hidden-information O
and O
hidden-action O
. O
Communication B-KEY
Complexity O
of O
Common O
Voting O
Rules O
* O
ABSTRACT O
We O
determine O
the O
communication B-KEY
complexity O
of O
the O
common O
voting O
rules O
. O
The O
rules O
-LRB- O
sorted O
by O
their O
communication B-KEY
complexity O
from O
low O
to O
high O
-RRB- O
are O
plurality O
, O
plurality O
with O
runoff O
, O
single O
transferable O
vote O
-LRB- O
STV O
-RRB- O
, O
Condorcet O
, O
approval O
, O
Bucklin O
, O
cup O
, O
maximin O
, O
Borda O
, O
Copeland O
, O
and O
ranked O
pairs O
. O
For O
each O
rule O
, O
we O
first O
give O
a O
deterministic O
communication B-KEY
protocol B-KEY
and O
an O
upper O
bound O
on O
the O
number O
of O
bits O
communicated B-KEY
in O
it O
; O
then O
, O
we O
give O
a O
lower O
bound O
on O
-LRB- O
even O
the O
nondeterministic O
-RRB- O
communication B-KEY
requirements O
of O
the O
voting B-KEY
rule O
. O
The O
bounds O
match O
for O
all O
voting B-KEY
rules O
except O
STV O
and O
maximin O
. O
A O
New O
Approach O
for O
Evaluating B-KEY
Query B-KEY
Expansion I-KEY
: O
Query-Document O
Term O
Mismatch O
ABSTRACT O
The O
effectiveness O
of O
information B-KEY
retrieval I-KEY
-LRB- O
IR O
-RRB- O
systems O
is O
influenced O
by O
the O
degree O
of O
term O
overlap O
between O
user O
queries O
and O
relevant B-KEY
documents I-KEY
. O
Query-document O
term O
mismatch O
, O
whether O
partial O
or O
total O
, O
is O
a O
fact O
that O
must O
be O
dealt O
with O
by O
IR O
systems O
. O
Query B-KEY
Expansion I-KEY
-LRB- O
QE O
-RRB- O
is O
one O
method O
for O
dealing O
with O
term O
mismatch O
. O
IR O
systems O
implementing O
query B-KEY
expansion I-KEY
are O
typically O
evaluated B-KEY
by O
executing O
each O
query O
twice O
, O
with O
and O
without O
query B-KEY
expansion I-KEY
, O
and O
then O
comparing O
the O
two O
result O
sets O
. O
While O
this O
measures O
an O
overall O
change O
in O
performance O
, O
it O
does O
not O
directly O
measure O
the O
effectiveness O
of O
IR O
systems O
in O
overcoming O
the O
inherent O
issue O
of O
term O
mismatch O
between O
the O
query O
and O
relevant B-KEY
documents I-KEY
, O
nor O
does O
it O
provide O
any O
insight O
into O
how O
such O
systems O
would O
behave O
in O
the O
presence O
of O
query-document O
term O
mismatch O
. O
In O
this O
paper O
, O
we O
propose O
a O
new O
approach O
for O
evaluating B-KEY
query B-KEY
expansion I-KEY
techniques O
. O
The O
proposed O
approach O
is O
attractive O
because O
it O
provides O
an O
estimate O
of O
system O
performance O
under O
varying O
degrees O
of O
query-document O
term O
mismatch O
, O
it O
makes O
use O
of O
readily O
available O
test O
collections O
, O
and O
it O
does O
not O
require O
any O
additional O
relevance O
judgments O
or O
any O
form O
of O
manual O
processing O
. O