Sensitivity of optimal prices to system parameters in a steady-state service facility We consider the problem of maximizing the long-run average reward in a service facility with dynamic pricing. We investigate sensitivity of optimal pricing policies to the parameters of the service facility which is modelled as an M/M/s/K M / M / s / K queueing system. Arrival process to the facility is Poisson with arrival rate a decreasing function of the price currently being charged by the facility. We prove structural results on the optimal pricing policies when the parameters in the facility change. Namely, we show that optimal prices decrease when the capacity of the facility or the number of servers in the facility increase. Under a reasonable assumption, we also show that optimal prices increase as the overall demand for the service provided by the facility increases or when the service rate of the facility decreases. We illustrate how these structural results simplify the required computational effort while finding the optimal policy.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

stochastic programming
markov decision processes
robustness and sensitivity analysis


a self-organizing p2p system with multi-dimensional structure This paper presents and analyzes Self-CAN, a self-organizing P2P system that, while relying on the multi-dimensional structured organization of peers provided by CAN, exploits the operations of ant-based mobile agents to sort the resource keys and distribute them to peers. The benefits of the self-organization approach are remarkable, starting from increased flexibility and robustness, to better load balancing characteristics. Most notably, peer indexes and resource keys can be defined on different and independent spaces, which overcomes the main limitation of standard structured P2P systems, i.e., the necessity of assigning each key to a peer having a specified index. This decoupling opens the possibility of giving a semantic meaning to resource keys and enables the efficient execution of multi-dimensional range queries, which are essential in some types of distributed systems, for example in Grids.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

bio-inspired
self-organizing
peer-to-peer
key-value storage
resource discovery


self-organized traffic control In this paper we propose and present preliminary results on the migration of traffic lights as roadside-based infrastructures to in-vehicle virtual signs supported only by vehicle- to-vehicle communications. We design a virtual traffic light protocol that can dynamically optimize the flow of traffic in road intersections without requiring any roadside infrastructure. Elected vehicles act as temporary road junction infrastructures and broadcast traffic light messages that are shown to drivers through in-vehicle displays. This approach renders signalized control of intersections truly ubiquitous, which significantly increases the overall traffic flow. We pro- vide compelling evidence that our proposal is a scalable and cost-effective solution to urban traffic control.

O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

self-organized traffic
v2v communication


Search strategies on a new health information retrieval system Purpose - The goals of this study are: to evaluate the merits of a newly developed health information retrieval system; to investigate users' search strategies when using the new search system; and to study the relationships between users' search strategies and their prior topic knowledge. Design/methodology/approach - The paper developed a new health information retrieval system called MeshMed. A term browser and a tree browser are included in the new system in addition to the traditional search box. The term browser allows a user to search Medical Subject Heading (MeSH) terms using natural language. The tree browser presents a hierarchical tree structure of related MeSH terms. A user study with 30 participants was conducted to evaluate the benefits of MeshMed. Findings - The paper found that MeshMed provides a user with more choices to select an appropriate searching component and form more effective search strategies. Based on the time a participant spent using different MeshMed components, the paper identified three different search styles: the traditional style, the novel style, and the balanced style, which falls in between. MeshMed was particularly helpful for users with low topic knowledge. Originality/value - A new health information retrieval system (MeshMed) was designed and developed (and is currently available at http://129.89.43.129/meshmed). This is the first study to explore users' search strategies on such a system. The study results can inform the design of future clinical-oriented health information retrieval systems.

O O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O

knowledge management
hospitals
information systems


ANFIS approach to the scour depth prediction at a bridge abutment An accurate estimation of the maximum possible scour depth at bridge abutments is of paramount importance in decision-making for the safe abutment foundation depth and also for the degree of scour counter-measure to be implemented against excessive scouring. Despite analysis of innumerable prototype and hydraulic model studies in the past, the scour depth prediction at the bridge abutments has remained inconclusive. This paper presents an alternative to the conventional regression model (RM) in the form of an adaptive network-based fuzzy inference system (ANFIS) modelling. The performance of ANFIS over RM and artificial neural networks (ANNs) is assessed here. It was found that the ANFIS model performed best among of these methods. The causative variables in raw form result in a more accurate prediction of the scour depth than that of their grouped form.

O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

anfis and regression analysis
local scour
neural network


An Improved Strength Pareto Evolutionary Algorithm 2 with application to the optimization of distributed generations This paper presents an Improved Strength Pareto Evolutionary Algorithm 2 (ISPEA2), which introduces a penalty factor in objective function constraints, uses adaptive crossover and a mutation operator in the evolutionary process, and combines simulated annealing iterative process over SPEA2. The testing result of ISPEA2 by authoritative testing functions meets the requirement of Petro-optimum fronts. The case study result shows that the proposed algorithm provides a rapid convergence in obtaining Pareto-optimal solutions during the calculation process of evolution. Based on the fuzzy set theory, ISPEA2 is able to solve the multi-objective problems in the IEEE 33-bus system, and its validity and practicality are demonstrated by the utilization on DGs economic dispatch and optimal operation in the field of power industry.

O B I I I I O O O O O O O O O O O O O B I I I I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

improved strength pareto evolutionary algorithm

distribution power system
distributed generation
coordinative optimization


A distributed instrument for performance analysis of real-time ethernet networks Ethernet technology is widely used in real-time industrial automation. Thanks to real-time Ethernet (RTE) protocols, defined in IEC61784-2 standard, new top-performance automation solutions can be created. Such systems may have communication cycle time down to tens of mu s and cycle jitter less than 1 mu s, making network testing and debugging very critical. Existing network and protocol analyzers can perform detailed local analysis, but characterization of high-performance RTE systems requires measurement of transmission delays and these instruments cannot be adequately synchronized among them to realize a distributed measurement network. This paper introduces a new low-cost distributed measurement instrument to measure timing characteristics of RTE nodes (end-to-end delays, synchronization, etc.). The proposed instrument has multiple FPGA-based probes that allow for simultaneous/synchronized logging on different place of the target RTE network. A PC-based "monitor station" stores all the data, ready for further elaboration. Architecture details are discussed, a prototype has been realized, and some experimental results are presented. For instance, synchronization accuracy between probes is below 100 ns.

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ethernet network
fieldbus
network synchronization
real time


documentation standards for beginning students The importance of writing programs that are readable has finally gained preeminence in the struggle with such competing and contradictory goals as cuteness and optimization of code. As a result, a much greater stress on documentation standards is found in computer science education these days. Industry and government standards for documentation are being more widely adhered to and certain points of agreement have emerged. Some excellent books have been written that cover the subject (Van Tassel, 1974; Ledgard, 1975; Kernighan & Plauger, 1974); however it is safe to say that both the exhaustive treatment of the subject in such publications and the extremely high standards proposed probably preclude wholesale adoption by instructors of beginning level programming courses. What is proposed here is a set of common sense, scaled down documentation standards for the student in a first programming course in, say, FORTRAN, PL/I, ALGOL, or Basic. The following represents an amalgam of documentation requirements achieved as a result of teaching introductory programming to college students for nine years. The actual sources have been the literature, colleagues, and last but not least, experience. They are not intended to represent an only or best approach; the author has recently encountered other efforts in this direction that must surely be as reasonable and effective. It does represent one educator's approach; it is sufficiently scaled down so that one might reasonably expect to use it as a standard for beginning students; and it may be most useful as a contributor of components to be integrated into a more effective set of standards. The basics of documentation and readable programming include comments, meaningful variable names, labelled output, flowcharts, and clear program flow. The major components of and basic rules for each of these categories will be presented in the context of the needs and limitations of the beginning student.

B O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O B O O O O O O B O B O O O O B I I O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O B B O O O O O B B I O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B B O O O O O O B O O O O O O O O O O B O O O O O O O O B

requirements
use
goals
computer science education
context
teaching
experience
writing
student
program
introductory programming
author
code
flow
stress
documentation
rules

point standardization direct component variability public industrial adopt effect governance integrability


Differential space-time modulation for DS-CDMA systems Differential space-time modulation (DSTM) schemes were recently proposed to fully exploit the transmit and receive antenna diversities without the need for channel state information. DSTM is attractive in fast flat fading channels since accurate channel estimation is difficult to achieve. In this paper. we propose a new modulation scheme to improve the performance of DS-CDMA systems in fast time-dispersive fading channels. This scheme is referred to as the differential space-time modulation for DS-CDMA (DST-CDMA) systems. The new modulation and demodulation schemes are especially studied for the fast fading down-link transmission in DS-CDMA systems employing multiple transmit antennas and one receive antenna. We present three demodulation schemes. referred to as the differential space-time Rake (DSTR) receiver, differential space-time deterministic (DSTD) receiver, and differential space-time deterministic de-prefix (DSTDD) receiver, respectively. The DSTD receiver exploits the known information of the spreading sequences and their delayed paths deterministically besides the Rake-type combination: consequently, it can outperform the DSTR receiver. which employs the Rake-type combination only, especially for moderate-to-high SNR. The DSTDD receiver avoids the effect of intersymbol interference and hence can offer better performance than the DSTD receiver. Copyright (C) 2001 John Wiley Sons, Ltd.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

wireless communications
space-time coding
smart antennas
spread spectrum
ds-cdma
rake receiver


On the normalization of interval and fuzzy weights The normalization of interval and fuzzy weights is often necessary in multiple criteria decision analysis (MCDA) under uncertainty, especially in analytic hierarchy process (AHP) with interval or fuzzy judgements. The existing normalization methods based on interval arithmetic and fuzzy arithmetic are found flawed and need to be revised. This paper presents the correct normalization methods for interval and fuzzy weights and offers relevant theorems in support of them. Numerical examples are examined to show the correctness of the proposed normalization methods and their differences from those existing normalization methods. (C) 2006 Elsevier B.V. All rights reserved.

O O B O O O B I O B O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O B I O O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O O O O

interval weights
multiple criteria decision making


A queue with semi-Markovian batch plus Poisson arrivals with application to the MPEG frame sequence We consider a queueing system with a single server having a mixture of a semi-Markov process (SMP) and a Poisson process as the arrival process, where each SMP arrival contains a batch of customers. The service times are exponentially distributed. We derive the distributions of the queue length of both SMP and Poisson customers when the sojourn time distributions of the SMP have rational Laplace-Stieltjes transforms. We prove that the number of unknown constants contained in the generating function for the queue length distribution equals the number of zeros of the denominator of this generating function in the case where the sojourn times of the SMP follow exponential distributions. The linear independence of the equations generated by those zeros is discussed for the same case with additional assumption. The necessary and sufficient condition for the stability of the system is also analyzed. The distributions of the waiting times of both SMP and Poisson customers are derived. The results are applied to the case in which the SMP arrivals correspond to the exact sequence of Motion Picture Experts Group ( MPEG) frames. Poisson arrivals are regarded as interfering traffic. In the numerical examples, the mean and variance of the waiting time of the ATM cells generated from the MPEG frames of real video data are evaluated.

O B O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B I O O O O O O O B O O O O O O O

semi-markov process
batch arrival
group of pictures (gop)


FRACTAL DIMENSION AS A DESCRIPTOR OF URBAN GROWTH DYNAMICS The objective of this paper is to examine the development of the urban form of the city of Olomouc since the 1920s in terms of fractal dimension, and to link the observation with two other descriptors of shape - area and perimeter. The fractal dimension of built-up areas and fractal dimension of the boundary of the city are calculated employing the box-counting method; the possibilities of their interpretation and usage in urban planning are discussed. The process of urban growth is observed with respect to its fractality and perspectives of this approach are discussed. An interesting dependence between area and its fractal dimension is derived.

B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O

box-counting method
area/perimeter relation


Adaptive critics for dynamic optimization A novel action-dependent adaptive critic design (ACD) is developed for dynamic optimization. The proposed combination of a particle swarm optimization-based actor and a neural network critic is demonstrated through dynamic sleep scheduling of wireless sensor motes for wildlife monitoring. The objective of the sleep scheduler is to dynamically adapt the sleep duration to nodes battery capacity and movement pattern of animals in its environment in order to obtain snapshots of the animal on its trajectory uniformly. Simulation results show that the sleep time of the node determined by the actor critic yields superior quality of sensory data acquisition and enhanced node longevity.

O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

adaptive critic design
sleep scheduling
wildlife monitoring

energy efficiency
wireless sensor networks


linearity and recursion in a typed lambda-calculus We show that the full PCF language can be encoded in L _rec, a syntactically linear ?-calculus extended with numbers, pairs, and an unbounded recursor that preserves the syntactic linearity of the calculus. We give call-by-name and call-by-value evaluation strategies and discuss implementation techniques for L _rec, exploiting its linearity.

O O B O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


power aware page allocation One of the major challenges of post-PC computing is the need to reduce energy consumption, thereby extending the lifetime of the batteries that power these mobile devices. Memory is a particularly important target for efforts to improve energy efficiency. Memory technology is becoming available that offers power management features such as the ability to put individual chips in any one of several different power modes. In this paper we explore the interaction of page placement with static and dynamic hardware policies to exploit these emerging hardware features. In particular, we consider page allocation policies that can be employed by an informed operating system to complement the hardware power management strategies. We perform experiments using two complementary simulation environments: a trace-driven simulator with workload traces that are representative of mobile computing and an execution-driven simulator with a detailed processor/memory model and a more memory-intensive set of benchmarks (SPEC2000). Our results make a compelling case for a cooperative hardware/software approach for exploiting power-aware memory, with down to as little as 45\% of the Energy Delay for the best static policy and 1\% to 20\% of the Energy Delay for a traditional full-power memory.

B O O B O O O O O O O O O O O O O B I O O O B O O B O B O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O B O O O B O O O B O O B O O O B B O O B O O B O O O O O O B O O O O O O O O B I O O O B B O B O O O O O O B B O O O O B B O O O O B I O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B B O O O O B O O O O O O B B O O O O O

lifetime
traces
policy
simulation
batteries
delay
case
paper
interaction
strategies
environments
energy consumption
workload
exploit
dynamic
energy
operating system
placement
power
hardware
mobile computing
allocation

challenge
paging
benchmark
memory model
computation
experience
informal
power-aware
exploration
processor
software
technologies
mobile device
cooperation
memorialized
power-management
feature
energy efficiency


Change rules for hierarchical beliefs The paper builds a belief hierarchy as a framework common to all uncertainty measures expressing that an actor is ambiguous about his uncertain beliefs. The belief hierarchy is further interpreted by distinguishing physical and psychical worlds, associated to objective and subjective probabilities. Various rules of transformation of a belief hierarchy are introduced, especially changing subjective beliefs into objective ones. These principles are applied in order to relate different contexts of belief change, revising, updating and even focusing. The numerous belief change rules already proposed in the literature receive epistemic justifications by associating them to specific belief hierarchies and change contexts. As a result, it is shown that the resiliency of probability judgments may have some limits and be reconciled with the possibility of learning from factual messages. (C) 2011 Published by Elsevier Inc.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I B B O O B O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

belief change
focusing
revising
updating

hierarchical belief
objective probability
subjective probability


A characterization of the two-commodity network design problem We study the uncapacitated version of the two-commodity network design problem. We characterize optimal solutions and show that when flow costs are zero there is an optimal solution with at most one shared path. Using this characterization, we solve the problem on a transformed graph with O(n) nodes and O(m) arcs based on a shortest path algorithm. Next, we describe a linear programming reformulation of the problem using O(m) variables and O(n) constraints and show that it always has an integer optimal solution. We also interpret the dual constraints and variables as generalizations of the are constraints and node potentials for the shortest path problem. We show that the polyhedron described by the constraints of the reformulation always has an integer optimal solution for a more general two-commodity problem with flow costs and an additional condition on the cost function. (C) 2000 John Wiley & Sons, Inc.

O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


On the minimum number of negations leading to super-polynomial savings We show that an explicit sequence of monotone functions f(n): {0, 1}(n) --> {0, 1}(m) (m less than or equal to n) can be computed by Boolean circuits with polynomial (in n) number of And, Or and Not gates, but every such circuit must use at least log n - O(log log n) Not gates. This is almost optimal because results of Markov [J. ACM 5 (1958) 331] and Fisher [Lecture Notes in Comput. Sci., Vol. 33, Springer, 1974, p. 71] imply that, with only small increase of the total number of gates, any circuit in n variables can be simulated by a circuit with at most [log (n + 1)] Not gates. (C) 2003 Elsevier B.V. All rights reserved.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

computational complexity
negation-limited circuits


DIFFERENTIAL LOG-DOMAIN WAVE ACTIVE FILTERS In this paper, the design of differential log-domain wave filters is outlined which is based on the log-domain wave technique. The differential configuration is achieved by introducing the differential log-domain wave equivalent. The resulting filters inherit the good characteristics of the wave active filters, are very modular and easy to design. The method is demonstrated by a design example and its validity is verified through simulations results.

O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O

analogue filters
differential filters
log-domain filters


A hybrid method based on linear programming and tabu search for routing of logging trucks In this paper, we consider an operational routing problem to decide the daily routes of logging trucks in forestry. This industrial problem is difficult and includes aspects such as pickup and delivery with split pickups, multiple products, time windows, several time periods, multiple depots, driver changes and a heterogeneous truck fleet. In addition, the problem size is large and the solution time limited. We describe a two-phase solution approach which transforms the problem into a standard vehicle routing problem with time windows. In the first phase, we solve an LP problem in order to find a destination of flow from supply points to demand points. Based on this solution, we create transport nodes which each defines the origin(s) and destination for a full truckload. In phase two, we make use of a standard tabu search method to combine these transport nodes, which can be considered to be customers in vehicle routing problems, into actual routes. The tabu search method is extended to consider some new features. The solution approach is tested on a set of industrial cases from major forest companies in Sweden.

O O O O O B I O B I O B O O O O O O O O O O B O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O

forestry
routing
tabu search
linear programming


The definition of assembly line balancing difficulty and evaluation of balance solution quality Assembly line balancing is a classic ill-structured problem where total enumeration is infeasible and optimal solutions uncertain for industrial problems. A quantitative approach to classifying problem difficulty and solution quality is therefore important. Two existing measures of difficulty, order strength and west ratio are compared to a new compound expression of difficulty, project index. Project index is based on individual assessment of precedence (precedence index) and task time (task time index). The current working definition of project index is given. Early criteria for judging assembly lines use balance delay and smoothness index, both are flawed as criteria. Line and balance efficiency are developed as more appropriate. Project index, line and balance efficiency will be illustrated for a published test-case examined by the A?Line balancing package. The potential for a learning approach, selecting models to suit problems using the measures of difficulty, will form part of the conclusions within this paper.

O O O O O B O O B O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O


A class-oriented feature selection approach for multi-class imbalanced network traffic datasets based on local and global metrics fusion Feature selection is often used as a pre-processing step for machine learning based network traffic classification. Many feature selection techniques have been developed to find an optimal subset of relevant features and to improve overall classification accuracy. But such techniques ignore the class imbalance problem encountered in network traffic classification. The selected feature subset may bias towards the traffic class that occupies the majority of traffic flows on the Internet. To address this issue, this paper proposes a new approach, called class-oriented feature selection (COFS), to identify a relevant feature subset for every class. It combines the proposed local metric and the existing global metric to yield a potentially optimal feature subset for each class, and then removes the redundant features in each feature subset based on the weighted symmetric uncertainty. Additionally, to enhance the generalization on network traffic data, an ensemble learning based scheme is presented with COFS to overcome the negative impacts of the data drift on a traffic classifier. Experiments on real-world network traffic data show that COFS outperforms existing feature selection techniques in most cases. Moreover, our approach achieves >96% flow accuracy and >93% byte accuracy on average.

O O B I O O O O B I O O O O O O O O B I O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O

feature selection
data drift
network traffic


Identifying and quantifying structural nonlinearities in engineering applications from measured frequency response functions Engineering structures seldom behave linearly and, as a result, linearity checks are common practice in the testing of critical structures exposed to dynamic loading to define the boundary of validity of the linear regime. However, in large scale industrial applications, there is no general methodology for dynamicists to extract nonlinear parameters from measured vibration data so that these can be then included in the associated numerical models. In this paper, a simple method based on the information contained in the frequency response function (FRF) properties of a structure is studied. This technique falls within the category of single-degree-of-freedom (SDOF) modal analysis methods. The principle upon which it is based is effectively a linearisation whereby it is assumed that at given amplitude of displacement response the system responds at the same frequency as the excitation and that stiffness and damping are constants. In so doing, by extracting this information at different amplitudes of vibration response, it is possible to estimate the amplitude-dependent natural frequency and modal loss factor. Because of its mathematical simplicity and practical implementation during standard vibration testing, this method is particularly suitable for practical applications. In this paper, the method is illustrated and new analyses are carried out to validate its performance on numerical simulations before applying it to data measured on a complex aerospace test structure as well as a full-scale helicopter.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

nonlinear identification
nonlinear modal testing
nonlinear modal analysis
experimental


On the formal specification and verification of multi-agent systems This article describes first steps towards the formal specification and verification of multiagent systems, through the use of temporal belief logics. The article first describes Concurrent METATEM, a multi-agent programming language, and then develops a logic that may be used to reason about Concurrent METATEM systems. The utility of this logic for specifying and verifying Concurrent METATEM systems is demonstrated through a number of examples. The article concludes with a brief discussion on the wider implications of the work, and in particular on the use of similar logics for reasoning about multi-agent systems in general.

O O B I I I O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A contribution to multimedia document modeling and querying Metadata on multimedia documents may help to describe their content and make their processing easier, for example by identifying events in temporal media, as well as carrying descriptive information for the overall resource. Metadata is essentially static and may be associated with, or embedded in, the multimedia contents. The aim of this paper is to present a proposal for multimedia documents annotation, based on modeling and unifying features elicited from content and structure mining. Our approach relies on the availability of annotated metadata representing segment content and structure as well as segment transcripts. Temporal and spatial operators are also taken into account when annotating documents. Any feature is identified into a descriptor called "meta-document". These meta-documents are the basis of querying by adapted query languages.

O O O O O O O B B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O


A Comparison of Pressure and Tilt Input Techniques for Cursor Control Three experiments were conducted in this study to investigate the human ability to control pen pressure and pen tilt input, by coupling this control with cursor position, angle and scale. Comparisons between pen pressure input and pen tilt input have been made in the three experiments. Experimental results show that decreasing pressure input resulted in very poor performance and was not a good input technique for any of the three experiments. In "Experiment 1-Coupling to Cursor Position", the tilt input technique performed relatively better than the increasing pressure input technique in terms of time. even though the tilt technique had a slightly higher error rate. In "Experiment 2-Coupling to Cursor Angle", the tilt input performed a little better than the increasing pressure input in terms of time, but the gap between them is not so apparent as Experiment 1. In "Experiment 3-Coupling to Cursor Scale", tilt input performed a little better than increasing pressure input in terms of adjustment time. Based on the results of our experiments, we have inferred several design implications and guidelines.

O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O

target selection tasks
pen-based interfaces


A framework for analyzing the cognitive complexity of computer-assisted clinical ordering Computer-assisted provider order entry is a technology that is designed to expedite medical ordering and to reduce the frequency of preventable errors. This paper presents a multifaceted cognitive methodology for the characterization of cognitive demands of a medical information system. Our investigation was informed by the distributed resources (DR) model, a novel approach designed to describe the dimensions of user interfaces that introduce unnecessary cognitive complexity. This method evaluates the relative distribution of external (system) and internal (user) representations embodied in system interaction. We conducted an expert walkthrough evaluation of a commercial order entry system, followed by a simulated clinical ordering task performed by seven clinicians. The DR model was employed to explain variation in user performance and to characterize the relationship of resource distribution and ordering errors. The analysis revealed that the configuration of resources in this ordering application placed unnecessarily heavy cognitive demands on the user, especially on those who lacked a robust conceptual model of the system. The resources model also provided some insight into clinicians interactive strategies and patterns of associated errors. Implications for user training and interface design based on the principles of humancomputer interaction in the medical domain are discussed.

O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

medical errors
cognitive evaluation
distributed cognition
information systems


Crack propagation analysis in composite materials by using moving mesh and multiscale techniques A novel multiscale method for crack propagation analysis in composites is proposed. An adaptive model refinement is used during crack propagation to improve efficiency. Competition between different damage mechanisms is handled during crack simulation. Matrix cracking is modeled by a novel optimization strategy based on moving meshes. The proposed approach is validated by original comparisons with existing methods.

B I O O B I O O B I O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

composite materials
crack propagation
moving mesh

concurrent multiscale methods
micromechanics
interface debonding


Motivations in virtual health communities and their relationship to community, connectedness and stress This study explores the relationships between motivations for joining virtual health communities, online behaviors, and psycho-social outcomes. A sample of 144 women from two virtual health communities focusing on infertility completed survey measures assessing motivations, posting and receiving support, connectedness, community, and stress. Our results indicate that socio-emotional support motivations for joining the community were associated with posting support within the virtual community, while informational motivations were related to receiving support. Further, receiving support was associated with greater sense of virtual community as well as more general feelings of connectedness, which was related to less stress. Implications for virtual health community research are discussed.

B O B I I O O O O O B O B O O O O O O B O O B I I O O O O O O O O O O O O B I I O O B O O O O B O O O O B O O B O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O B I I I O O O O O O O B O O O O O B O O O O O O O O

virtual health communities
motivations
connectedness
stress
sense of virtual community
infertility


Enterprise resource planning: Implementation procedures and critical success factors Enterprise resource planning (ERP) systems are highly complex information systems. The implementation of these systems is a difficult and high cost proposition that places tremendous demands on corporate time and resources. Many ERP implementations have been classified as failures because they did not achieve predetermined corporate goals. This article identifies success factors, software selection steps, and implementation procedures critical to a successful implementation. A case study of a largely successful ERP implementation is presented and discussed in terms of these key factors.

B I I B I O B I I B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O

enterprise resource planning
critical success factors
implementation procedures

business process reengineering
project management


DFLOWZ: A free program to evaluate the area potentially inundated by a debris flow Debris flow inundated area can be estimated using scaling relationships. We provide a free, open-source program to evaluate debris flow hazard. The model considers the uncertainties in scaling relationships and input data. A Graphical User Interface facilitate the process of susceptibility mapping.

O O O O O O O O O O O O B I B I O O O O O O B I O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O


A novel approach to identify optimal access point and capacity of multiple DGs in a small, medium and large scale radial distribution systems Distributed generation (DG) sources are predicated to play major role in distribution systems due to the demand growth for electrical energy. Location and sizing of DG sources found to be important on the system losses and voltage stability in a distribution network. In this paper an efficient technique is presented for optimal placement and sizing of DGs in a large scale radial distribution system. The main objective is to minimize network power losses and to improve the voltage stability. A detailed performance analysis is carried out on 33-bus, 69-bus and 118-bus large scale radial distribution systems to demonstrate the effectiveness of the proposed technique. Performing multiple power flow analysis on 118-bus system, the effect of DG sources on the most sensitive buses to voltage collapse is also carried out.

O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B I I I I O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O

distributed generation
large scale radial distribution system
voltage


Robust discrete control of nonlinear processes: Application to chemical reactors Trajectory tracking or rejecting persistent disturbances with digital controllers in nonlinear processes is a class of problems where classical control methods breakdown since it is very difficult to describe the dynamic behavior over the entire trajectory. In this paper, a model-based robust control scheme is proposed as a potential solution approach for these systems. The proposed control algorithm is a robust error feedback controller that allows us to track predetermined operation profiles while attenuating the disturbances and maintaining the stability conditions of the nonlinear processes. Various numerical simulation examples demonstrate the effectiveness of this robust scheme. Two examples deal with effective trajectory tracking in chemical reactors over a wide range of operating conditions. The third example analyses the attenuation of periodic load in a biological reactor. All examples illustrate the ability of the robust control scheme to provide good control in the face of parameter uncertainties and load disturbances. (C) 2008 Elsevier Ltd. All rights reserved.

B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Wavelet-based statistical approach for speckle reduction in medical ultrasound images A novel speckle-reduction method is introduced, based on soft thresholding of the wavelet coefficients of a logarithmically transformed medical ultrasound image. The method is based on the generalised Gaussian distributed (GGD) modelling of sub-band coefficients. The method used was a variant of the recently published BayesShrink method by Chang and Vetterli, derived in the Bayesian framework for denoising natural images. It was scale adaptive, because the parameters required for estimating the threshold depend on scale and sub-band data. The threshold was computed by Ksigma(2)/sigma(x), where sigma and sigma(x) were the standard deviation of the noise and the sub-band data of the noise-free image, respectively, and K was a scale parameter. Experimental results showed that the proposed method outperformed the median filter and the homomorphic Wiener filter by 29% in terms of the coefficient of correlation and 4% in terms of the edge preservation parameter. The numerical values of these quantitative parameters indicated the good feature preservation performance of the algorithm, as desired for better diagnosis in medical image processing.

O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

speckle reduction
soft thresholding
wiener filter
median filter
bayesshrink


Computer-based imaging and interventional MRI: applications for neurosurgery Advances in computer technology and the development of open MRI systems definitely enhanced intraoperative image-guidance in neurosurgery. Based upon the integration of previously acquired and processed 3D information and the corresponding anatomy of the patient, this requires computerized image-processing methods (segmentation, registration, and display) and fast image integration techniques. Open MR systems equipped with instrument tracking systems, provide an interactive environment in which biopsies and minimally invasive interventions or open surgeries can be performed. Enhanced by the integration of multimodal imaging these techniques significantly improve the available treatment options and can change the prognosis for patients with surgically treatable diseases.

O O O B I O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

image-guidance
minimally invasive therapy
surgical planning


Dynamic response of a pile embedded in a porous medium subjected to plane SH waves In this paper, the frequency domain dynamic response of a pile embedded in a porous medium subjected to SH seismic waves is investigated. The surrounding porous medium of the pile is described by Biots poro-elastic theory, while the pile embedded in the porous medium is treated as a beam and described by a beam vibration theory. Using the Hankel transformation method, the fundamental solution for a half-space porous medium subjected to a horizontal circular patch load is established. According to the fictitious pile methodology, the second kind of Fredholm integral equation for the pile is established in terms of the obtained fundamental solution and free wave field. The solution of the integral equation yields the dynamic response of the pile to plane SH waves. Numerical results indicate that the parameters of the porous medium, the pile and incident waves have considerable influences on the dynamic response of the pile and the porous medium.

O O O O B O O O O O O O O B I O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B I I O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O B O O O O O O O O O O O O B O O O O

pile
sh waves
fredholm integral equation


Towards computational models of animal cognition, an introduction for computer scientists The last few years of the twentieth century witnessed the emerging convergence of biology and computer science and this trend has been accelerating since then. The study of animal behavior or behavior biology has been one of the major contributors for this convergence. Behavior is fascinating because it is the response of an organism to internal and external signals and it is controlled by complex interactions among nerves, the sensory and the motor systems. To some extent, behavior is similar to the output (or response) of a computer system or a network node if we consider an animal brain as a computer node. This paper is the first in a two-part series in which I review the state-of-the-art research in behavior biology inspired computing and communication, with the first part focusing on animal cognition and the second part on animal communication ( Ma, 2014). The present article also assumes the task of presenting a general introduction on behavior biology literature, which sets a foundation for synthesizing both parts of the series but the synthesis will be performed in the second part of the series. I sets three objectives in this cognition part: (i) to present a brief overview on the literature of behavior biology for computer scientists; (ii) to summarize the state-of-the-art studies in several cognitive aspects of animal behavior: focusing on emerging research in cognitive ecology, social learning and innovation, as well as animal logics; (iii) to review some important existing studies inspired by animal behavior and further present a perspective on the future research. These cognition-related topics offer insights for research fields such as machine learning, human computer interactions (HCI), brain computer interfaces (BCIs), evolutionary computing, pervasive computing, etc. In perspective, I suggest that the interaction between behavioral biology and computer science should be bidirectional, and a new subject, behavioral informatics, or more general computational behavior biology, should be developed by the cooperative efforts between biologists and computer scientists.

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I I O O O O O O O O O O O O

animal cognition
cognitive ecology
social learning
behavioral informatics
computational behavior biology


Crossing boundaries in Facebook: Students framing of language learning activities as extended spaces Young peoples interaction online is rapidly increasing, which enables new spaces for communication; the impact on learning, however, is not yet acknowledged in education. The aim of this exploratory case study is to scrutinize how students frame their interaction in social networking sites (SNS) in school practices and what that implies for educational language teaching and learning practices. Analytically, the study departs from a sociocultural perspective on learning, and adopts conceptual distinctions of frame analysis. The results based on ethnographic data from a Facebook group in English-learning classes, with 60 students aged between 13 and 16 from Colombia, Finland, Sweden and Taiwan indicate that there is a possibility for boundary crossing, which could generate extended spaces for collaborative language-learning activities in educational contexts where students combine their school subject of learning language and their communicative use of language in their everyday life. Such extended spaces are, however, difficult to maintain and have to be recurrently negotiated. To take advantage of young peoples various dynamic communicative uses of language in their everyday life in social media, the implementation of such media for educational purposes has to be deliberately, collaboratively and dynamically negotiated by educators and students to form a new language-learning space with its own potentials and constraints.

O O O B O B O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

sns
boundary crossing
extended spaces
facebook
framing


A study of the stabilizing process of unstable structures by dynamic relaxation method In this paper, the stabilizing process of unstable structures is studied by dynamic relaxation method. The process of applying the internal force to unstable structures is called as stabilizing process of unstable structure. The initial behavior of unstable structures such as cables, pneumatic structures or cable domes, are unstable state because of no initial internal stiffness. The dynamic relaxation method is the energy minimization technique that searches the static equilibrium state by simple vector iteration method. Because the dynamic relaxation method does not need to assemble the tangential stiffness matrix of structure during each iteration of the stabilizing process, the computational effort and CPU run-time can be reduced. The finite difference integration technique is used to integrate the dynamic equilibrium equation for static equilibrium state. Some numerical examples are presented to confirm the efficiency and applicability of dynamic relaxation method.

O O O O B I O B I O B I I O O O O B I O B I O O O B I I O O O O O O O O B I O O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I

unstable structures
stabilizing process
dynamic relaxation method


A novel parallelization approach for hierarchical clustering Identification of groups of genes that manifest similar expression patters is a key step in the analysis of gene expression data. Hierarchical clustering is developed for that purpose. A fundamental problem with the previous implementations of this clustering method is its limitation to handle large data sets within a reasonable time and memory resources. In this paper, we present a parallel approach for solving this problem. Implementation of the parallel algorithm is illustrated on data from high dimensional microarray experiments related to the gene expression in cancerous disease and Arabidopsis seedling growth. They show considerable reduction in computational time and inter-node communication overhead, especially for large data sets.

O O B O O O B O O O O O O O O O O O O O O O O O O B I O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O

clustering
parallelization
gene expression


Surjective multidimensional cellular automata are non-wandering: A combinatorial proof A combinatorial proof that surjective D-dimensional CA are non-wandering is given. This answers an old open question stated in Blanchard and Tisseur (2000) [3]. Moreover, an explicit upper bound for the return time is given. (C) 2013 Elsevier B.V. All rights reserved.

O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

combinatorial problems
symbolic dynamics
discrete dynamical systems


event-based application of ws-security policy on soap messages WS-Security and WS-Security Policy are the common standards for ensuring integrity and confidentiality for Web Service messages. On the one hand they allow very flexible definition of security requirements. On the other hand they lead to complex security administration and low performance message processing. In this paper, we present our solution for a security gateway, which uses complete event-based XML and WS-Security processing to create policy conforming SOAP messages. The evaluation of our implementation shows that the event-based approach leads to a much better performance than tree-based WS-Security implementations. Further, we discuss some problematical issues of WS-Security Policy processing, such as determination of digital identities.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ws-security
event-based processing
web services


A scheduling problem with three competing agents Scheduling with multiple agents has become a popular topic in recent years. However, most of the research focused on problems with two competing agents. In this article, we consider a single-machine scheduling problem with three agents. The objective is to minimize the total weighted completion time of jobs from the first agent given that the maximum completion time of jobs from the second agent does not exceed an upper bound and the maintenance activity from the third agent must be performed within a specified period of time. A lower bound based on job division and several propositions are developed for the branch-and-bound algorithm, and a genetic algorithm with a local search is constructed to obtain near-optimal solutions. In addition, computational experiments are conducted to test the performance of the algorithms.

O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

scheduling
total weighted completion time
maintenance activity


TSA: Tree-seed algorithm for continuous optimization This paper presents a new optimizer to solve continuous optimization problems. New optimizer is proposed by considering relations between trees and their seeds. The new optimizer is applied to solve 24 benchmark functions. The results of the proposed method are compared with state-of-arts methods. The proposed method is a useful optimizer for continuous optimization.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

heuristic search
tree and seed
numeric optimization
multilevel thresholding


Solving fuzzy Multidimensional Multiple-Choice Knapsack Problems: The multi-start Partial Bound Enumeration method versus the efficient epsilon-constraint method In this paper a new fuzzy Multidimensional Multiple-choice Knapsack Problem (MMKP) is proposed. In the proposed fuzzy MMKP, each item may belong to several groups according to a predefined fuzzy membership value. The total profit and the total cost of the knapsack problem are considered as two conflicting objectives. A mathematical approach and a heuristic algorithm are proposed to solve the fuzzy MMKP. One method is an improved version of a well-known exact multi-objective mathematical programming technique, called the efficient ?-constraint method. The second method is a heuristic algorithm called multi-start Partial-Bound Enumeration (PBE). Both methods are used to comparatively generate a set of non-dominated solutions for the fuzzy MMKP. The performance of the two methods is statistically compared with respect to a set of simulated benchmark cases using different diversity and accuracy metrics.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

fuzzy multidimensional multiple-choice knapsack problem

multi-start partial bound enumeration method


a trace transformation technique for communication refinement Models of computation like Kahn and dataflow process networks provide convenient means for modeling signal processing applications. This is partly due to the abstract primitives that these models offer for communication between concurrent processes. However, when mapping an application model onto an architecture, these primitives need to be mapped onto architecture level communication primitives. We present a trace transformation technique that supports a system architect in performing this communication refinement. We discuss the implementation of this technique in a tool for architecture exploration named SPADE and present examples.

O O O O O B O O O B O O O B B O O O O O O B I B O O O O O O O O O O O O O B O O O O O O O O B O O B O O O O O O O B O B O O O O O O O O O O O O O O O B O O O O B O O O O O B O B B O O O O B

communication
applications
examples
architecture
computation
implementation
tool
process
model
dataflow
signal processing
exploration

network traces systems abstraction concurrency map refine


A Regularity Condition of the Information Matrix of a Multilayer Perceptron Network The Fisher information matrix of a multi-layer perceptron network can be singular at certain parameters, and in such cases many statistical techniques based on asymptotic theory cannot be applied properly. In this paper, we prove rigorously that the Fisher information matrix of a three-layer perceptron network is positive definite if and only if the network is irreducible; that is, if there is no hidden unit that makes no contribution to the output and there is no pair of hidden units that could be collapsed to a single unit without altering the input-output map. This implies that a network that has a singular Fisher information matrix can be reduced to a network with a positive definite Fisher information matrix by eliminating redundant hidden units. Copyright 1996 Elsevier Science Ltd

O O O O O B I O O B I O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O

multilayer perceptron
information matrix

parametric estimation
irreducibility
minimality
sigmoidal function


how hci design influences web security decisions Even though security protocols are designed to make computer communication secure, it is widely known that there is potential for security breakdowns at the human-machine interface. This paper reports on a diary study conducted in order to investigate what people identify as security decisions that they make while using the web. The study aimed to uncover how security is perceived in the individual's context of use. From this data, themes were drawn, with a focus on addressing security goals such as confidentiality and authentication. This study is the first study investigating users' web usage focusing on their self-documented perceptions of security and the security choices they made in their own environment.

O B B O O B O O O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O B I O O O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O

participation retail phishing online trust


The complexity of finding arc-disjoint branching flows The concept of arc-disjoint flows in networks was recently introduced in Bang-Jensen and Bessy (2014). This is a very general framework within which many well-known and important problems can be formulated. In particular, the existence of arc-disjoint branching flows, that is, flows which send one unit of flow from a given source s s to all other vertices, generalizes the concept of arc-disjoint out-branchings (spanning out-trees) in a digraph. A pair of out-branchings B s , 1 + , B s , 2 + from a root s s in a digraph D=(V,A) D = ( V , A ) on n n vertices corresponds to arc-disjoint branching flows x1,x2 x 1 , x 2 (the arcs carrying flow in xi x i are those used in B s , i + , i=1,2 i = 1 , 2 ) in the network that we obtain from D D by giving all arcs capacity n?1 n ? 1 . It is then a natural question to ask how much we can lower the capacities on the arcs and still have, say, two arc-disjoint branching flows from the given root s s . We prove that for every fixed integer k?2 k ? 2 it is an NP-complete problem to decide whether a network N=(V,A,u) N = ( V , A , u ) where uij=k u i j = k for every arc ij i j has two arc-disjoint branching flows rooted at s s . a polynomial problem to decide whether a network N=(V,A,u) N = ( V , A , u ) on n n vertices and uij=n?k u i j = n ? k for every arc ij i j has two arc-disjoint branching flows rooted at s s .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

disjoint branchings
branching flow
polynomial algorithm
np-complete


Double-ended queues with impatience The effect of impatient behaviour is studied primarily in the context of double-ended queues where each demands service from the other, typically taxis and passengers. Related models, single queue, and double, with a variety of mechanisms are considered. Impatience is to be understood in a wider context than simply becoming tired of waiting: it can arise because the customer, for some reason, runs out of time (inventory and organ transplantation), or because an alternative service becomes available (communication applications). The emphasis in this paper is theoretical but a brief numerical assessment of operational consequences is given. The double-ended (or synchronization) queue is a model for a variety of service demanding/providing systems. In an orderly taxi rank at a railway station or airport, on one side a queue is formed by the arrival of stream of passengers who wait for taxis to their destinations while on the other side a queue of taxis waiting for passengers. Obviously, the two queues can never coexist. The concept of impatience enters when a taxi or passenger leaves the queue before receiving service. This concept of reneging is widely applicable. In health care, for example, organs are stored for transplantation for needful patients. Both the organs and the demands for them have limited lifetime. A similar scenario applies to perishable inventory systems. In a similar manner, the real-time communication networks admit impatient behaviour. A typical example is a processor-shared queue in data networks with random time-out periods or deadlines. The paper sets out the basics in a variety of theoretical model settings with the common feature of exponential arrival, service and impatience mechanisms. A brief discussion based on numerical calculation is given of some operational features of the models but the thrust is on the theoretical techniques needed to make meaningful operational assessments.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


SU-8 ridge-waveguide with holographic grating embedded in nanoimprinted groove Fabrication of SU-8 slab- and ridge-waveguides with holographic grating for DFB laser, effectively utilizing nanoimprint technology (NIL), is presented. Rhodamine-6G-doped SU-8 slab- and ridge-waveguides were embedded in grooves defined by NIL in UV curable resin. Utilization of NIL made it easier to form such a three-dimensional micro structure consisting of ridge stripe and fine corrugation grating. TE-polarized 587nm laser and TE-polarized 594nm light emissions were observed from the slab- and ridge-waveguides, respectively, when the waveguides were irradiated by 532nm pulsed Nd:YAG laser.

O O O B I O O O O O O O O O O O B I O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

polymer optics
su-8
waveguide
polymer dfb laser


Optical method for characterization of nanoplates in lyosol In the recent years, two-dimensional nanoparticles (the nanoplates) have become a subject of intense scientific researches and industrial applications. The liquid exfoliation of layered crystals becomes the most simple and efficient manufacturing method of graphene and layered compounds nanosheets. The primary product of the liquid exfoliation is a lyosol a colloidal suspension of desired nanoparticles in a fluid. The shape of the produced nanoparticles may be determined with the use of an electron microscopy (SEM). In the case of spherical particles the concentration and the particles size can be assessed by the light absorption and the dynamic laser light scattering (DLS) measurements respectively. We propose an optical method for fast and comprehensive characterization of shape and size of nanoplates in a lyosol. The system makes use of an optical goniometer. It allows to measure angular distribution of intensity of the light scattered on the lyosol sample. The distribution of the intensity (indicatrix) depends on the shape and size of the nanoparticles. We developed a method of theoretical indicatrix calculation of the nanoplates with the use of Amsterdam Discrete Dipole Approximation method. The experimentally measured indicatrix is compared with the theoretical calculations (standardized indicatrices). We observed that the nanoplate has a dual character of light scattering. It can scatter light as a small or big particle according to the direction of the incident light beam. We have applied the proposed method of characterization for a water suspension of graphene nanosheets. Results of the measurements are in good agreement with particles dimensions assessed with the SEM images and do not fit with the graphene dimensions estimated with the DLS method. It leads to a conclusion that the two-dimensional particles size estimation with the DLS is highly inaccurate.

O O O O O B O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O

graphene
nanoplates
discrete dipole approximation


What You See Is What You Code: A live algorithm development and visualization environment for novice learners Pedagogical algorithm visualization (AV) systems produce graphical representations that aim to assist learners in understanding the dynamic behavior of computer algorithms. In order to foster active learning, computer science educators have developed AV systems that empower learners to construct their own visualizations of algorithms under study. Notably, these systems support a similar development model in which coding an algorithm is temporally distinct from viewing and interacting with the resulting visualization. Given that they are known to have problems both with formulating syntactically correct code, and with understanding how code executes, novice learners would appear likely to benefit from a more live development model that narrows the gap between coding an algorithm and viewing its visualization. In order to explore this possibility, we have implemented What You See Is What You Code, an algorithm development and visualization model geared toward novices first learning to program under the imperative paradigm. In the model, the line of algorithm code currently being edited is reevaluated on every edit, leading to immediate syntactic feedback, along with immediate semantic feedback in the form of an AV. Analysis of usability and field studies involving introductory computer science students suggests that the immediacy of the model's feedback can help novices to quickly identify and correct programming errors, and ultimately to develop semantically correct code.

O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

novice programming environments
live programming environments
usability studies


INVER2DBASEA program to compute basement depths of density interfaces above which the density contrast varies with depth ? A computer program to invert the gravity anomalies of density interfaces above which the density contrast varies with depth, is presented. The sedimentbasement interface is approximated by an N-sided polygon. A function subprogram GR2DPOL and two subroutine subprograms ZOR2DPOL and SIMEQ support the main program. Subroutine ZOR2DPOL calculates the initial depth estimates of a density interface at all anomaly points on the principal profile using the infinite slab approximation. Function subprogram GR2DPOL computes the theoretical gravity anomaly of a density interface at each anomaly point on the profile and returns to the main program. Subroutine SIMEQ is used to solve n incremental depth parts of the vertices of a density interface. Partial derivatives are calculated by a simple finite-difference method. Normal equations are constructed and solved by Marquardt's algorithm. The proposed inversion scheme is independent on the equal station spacing criteria. The validity of the algorithm is demonstrated by calculating the basement depths of the Tucson basin, southern Arizona.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O

sedimentbasement interface
gravity anomaly
inversion

n-sided polygon
variable density contrast


Graph based construction of textured large field of view mosaics for bladder cancer diagnosis Large field-of-view panoramic images greatly facilitate bladder cancer diagnosis and follow-up. Such 2D mosaics can be obtained by registering the images of a video-sequence acquired during cystoscopic examinations. The scientific challenge in the registration process lies in the strong inter- and intra-patient texture variability of the images, from which primitives cannot be robustly extracted. State-of-the-art registration methods are not at the same time robust and accurate, especially for image pairs with a small amount of overlap (less than 90%) or strong perspective transformations. Moreover, no previous contribution to cystoscopy mosaicing presents panoramic images created from multiple overlapping sequences (e.g. zigzags or loop trajectories). We show how such overlapping sections can be automatically detected and present a novel registration algorithm that robustly superimposes non-consecutive image pairs, which are related by stronger perspective transformations and share less overlap than consecutive images (less than 50%). Globally coherent panoramic images are constructed using a non-linear optimization and a novel contrast-enhancing stitching method. Results on both phantom and patient data are obtained using constant algorithm parameters, which demonstrate the robustness of the proposed method. While the methods presented in this contribution are specifically designed for cystoscopy mosaicing, they can also be applied to more general mosaicing problems. We demonstrate this on a traditional stitching application, where a set of pictures of a building are stitched into a seamless, globally coherent panoramic image.

O O O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

image mosaicing
seamless panoramic stitching
image registration
endoscopy
graph cuts
higher order terms
non-linear refinement


an heuristic set for evaluation in information visualization Evaluation is a key research challenge within the international Information Visualization (InfoVis) community, and Heuristic Evaluation is one recognized method. Various sets of heuristics have been proposed but there remains no consensus as to which heuristics are most useful for addressing aspects specific to the complex interactive visual displays used in modern InfoVis systems. This paper presents a first effort to empirically determine a new set of such general heuristics tailored for Heuristic Evaluation of common and important usability problems in InfoVis techniques. Participants in the study rated how well a total of 63 heuristics from 6 earlier published heuristic sets could explain a collection of 74 usability problems derived from earlier InfoVis evaluations. The results were used to synthesize 10 heuristics that, as a set, provided the highest explanatory coverage. The paper also stresses the challenges for future research to validate and further improve upon this set.

O O O O O O B I O O O O O O O O O B I O O O B I O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O

heuristics
heuristic evaluation
information visualization


A Dependable Infrastructure for Cooperative Web Services Coordination A current trend in the web services community is to define coordination mechanisms to execute collaborative tasks involving multiple organizations. Following this tendency, in this paper the authors present a dependable (i.e., intrusion-tolerant) infrastructure for cooperative web services coordination that is based on the tuple space coordination model. This infrastructure provides decoupled communication and implements several security mechanisms that allow dependable coordination even in presence of malicious components. This work also investigates the costs related to the use of this infrastructure and possible web service applications that can benefit from it.

O O O O O B I I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O

coordination mechanisms
web service applications
web services coordination


Performance evaluation of an IEEE 802.15.4 sensor network with a star topology One class of applications envisaged for the IEEE 802.15.4 LR-WPAN (low data rate-wireless personal area network) standard is wireless sensor networks for monitoring and control applications. In this paper we provide an analytical performance model for a network in which the sensors are at the tips of a star topology, and the sensors need to transmit their measurements to the hub node so that certain objectives for packet delay and packet discard are met. We first carry out a saturation throughput analysis of the system; i.e., it is assumed that each sensor has an infinite backlog of packets and the throughput of the system is sought. After a careful analysis of the CSMA/CA MAC that is employed in the standard, and after making a certain decoupling approximation, we identify an embedded Markov renewal process, whose analysis yields a fixed point equation, from whose solution the saturation throughput can be calculated. We validate our model against ns2 simulations (using an IEEE 802.15.4 module developed by Zheng [14]). We find that with the default back-off parameters the saturation throughput decreases sharply with increasing number of nodes. We use our analytical model to study the problem and we propose alternative back-off parameters that prevent the drop in throughput. We then show how the saturation analysis can be used to obtain an analytical model for the finite arrival rate case. This finite load model captures very well the qualitative behavior of the system, and also provides a good approximation to the packet discard probability, and the throughput. For the default parameters, the finite load throughput is found to first increase and then decrease with increasing load. We find that for typical performance objectives (mean delay and packet discard) the packet discard probability would constrain the system capacity. Finally, we show how to derive a node lifetime analysis using various rates and probabilities obtained from our performance analysis model.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O

wireless sensor networks
performance analysis


navigation models for a flexible, multi-mode vr navigation framework Navigation is a key issue for Virtual Reality (VR) applications because it forms an integral part of the feeling of presence, which should be conveyed by VR applications. This paper presents several VR navigation modes which are useful for orientation and interaction in Virtual Environments (VEs). Due to the existence of different kinds of applications several navigation modes are required.

B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

virtual reality navigation
navigation techniques


Multiscale simulations: application to the heat transfer simulation of sliding solids Molecular dynamics is a powerful tool allowing the simulation of matter behaviour at the atomic scale. Due to computation time, it is clearly not possible to use molecular dynamics to simulate a forming process. However, atomistic simulations can be used to study and understand the physical phenomena that occur during matter deformation. As an example, heat transfer between the contacting solids in forming processes is one of the important physics phenomena that have to be taken into account in order to do realistic simulations. A multiscale analysis of heat transfer is presented. This analysis leads to two kinds of models: a macroscopic model which can be used for the simulation of the process itself and a microscopic model that is used to determine the parameters of the macroscopic model. In this microscopic model, the friction heat generation phenomena has to be described quite accurately. Friction heat is mainly due to plastic and elastic deformation and adhesion. Thus, to understand the underlying friction heat generation phenomena, atomistic simulations using molecular dynamics are carried out. It is shown that friction heat is the transformation of mechanical work given to the system at the macroscopic scale into potential energy during elastic deformation. This potential energy which is stored in the system is finally transformed into atomic kinetic energy (friction heat) during plastic transformation.

O O O O O B I O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O B I O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O

molecular dynamics
friction
atomic scale
heat transfer


L-p-Nested Symmetric Distributions In this paper, we introduce a new family of probability densities called L-p-nested symmetric distributions. The common property, shared by all members of the new class, is the same functional form rho(x)= (rho) over tilde (f(x)), where f is a nested cascade of L-p-norms parallel to x parallel to(p) = (Sigma vertical bar x(i)vertical bar(p))(1/p). L-p-nested symmetric distributions thereby are a special case of nu-spherical distributions for which f is only required to be positively homogeneous of degree one. While both, nu-spherical and L-p-nested symmetric distributions, contain many widely used families of probability models such as the Gaussian, spherically and elliptically symmetric distributions, L-p-spherically symmetric distributions, and certain types of independent component analysis (ICA) and independent subspace analysis (ISA) models, nu-spherical distributions are usually computationally intractable. Here we demonstrate that L-p-nested symmetric distributions are still computationally feasible by deriving an analytic expression for its normalization constant, gradients for maximum likelihood estimation, analytic expressions for certain types of marginals, as well as an exact and efficient sampling algorithm. We discuss the tight links of L-p-nested symmetric distributions to well known machine learning methods such as ICA, ISA and mixed norm regularizers, and introduce the nested radial factorization algorithm (NRF), which is a form of non-linear ICA that transforms any linearly mixed, non-factorial L-p-nested symmetric source into statistically independent signals. As a corollary, we also introduce the uniform distribution on the L-p-nested unit sphere.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

independent subspace analysis
nested radial factorization

non-linear independent component analysis

uniform distributions on mixed norm spheres


data delivery in fragmented wireless sensor networks using mobile agents Due to the wide range of applications in sensors and Wireless Sensor Networks (WSN), research in this area has recently received increasing attention. WSNs rely on network connectivity to deliver data to a base station through multihop communication. However, connectivity may not be always achievable for a number of reasons. In this paper, we study the problem of data delivery in disconnected WSNs. A special class of disconnected sensor networks called "Fragmented wireless sensor networks (FWSN)" is considered. A FWSN consists of several groups of connected sensors that we call "fragments". To achieve connectivity between these fragments, mobile agents move in the network and act as data relays between fragments, in order to eventually deliver data to the base station. The main contribution of this paper is the modeling of the movement of these mobile relay nodes as a closed queueing network to obtain steady state results of the distribution of the mobile relays in the network. Building on these results, we derive the distributions of the fragment-to-fragment, and fragment-to-sink delays. Comparing these analytical results to results from the TOSSIM simulator, it is shown that this model accurately captures the system behavior, and can be used to predict data delivery delays.

O O O O B I I O B I O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Implementation of conditional simulation by successive residuals ? Conditional simulation of ergodic and stationary Gaussian random fields using successive residuals is a new approach used to overcome the size limitations of the LU decomposition algorithm as well as provide fast updating of existing simulated realizations with new data. This paper discusses two different implementations of this approach. The implementations differ in the use of the new information available; in the first implementation new information is partially used to generate updated realizations; however, in the second implementation, the realizations are updated using all the new information available. The implementations are validated using the Walker Lake data set, and compared through a case study at a stockwork gold deposit.

O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

generalised sequential gaussian simulation


Completion of overdetermined parabolic PDEs In this paper we apply methods of commutative algebra to analysis of systems of PDEs. More precisely, we show that systems which are parabolic in a generalized sense are equivalent to certain completed systems which are parabolic in the standard sense. We also propose a constructive method for getting this completion, and Grobner basis methods, via symbol modules of the systems, play a central role in practical computations. Moreover, we can easily construct systems which are not parabolic in the generalized sense but nevertheless become parabolic when completed. (c) 2007 Elsevier Ltd. All rights reserved.

B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

overdetermined system
partial differential equation
parabolic system
graded module
free resolution


Steady-state analysis of a discrete-time batch arrival queue with working vacations This paper analyzes a discrete-time batch arrival queue with working vacations. In a Geo X / G / 1 system, the server works at a lower speed during the vacation period which becomes a lower speed operation period. This model is more appropriate for the communication systems with the transmit units arrived in batches. We formulate the system as an embedded Markov chain at the departure epoch and by the M/G/1-type matrix analytic approach, we derive the probability generating function (PGF) of the stationary queue length. Then, we obtain the distribution for the number of the customers at the busy period initiation epoch, and use the stochastic decomposition technique to present another equivalent PGF of the queue length. We also develop a variety of stationary performance measures for this system. Some special models and numerical results are presented. Finally, a real-world example in an Ethernet Passive Optical Network (EPON) is provided.

O O O O O B I O O B I O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

batch arrival
working vacations
stochastic decomposition

discrete-time queue
m/g/1-type matrix
ethernet passive optical network (epon)


BIMQL An open query language for building information models In this paper we present the on-going development of a framework for a domain specific, open query language for building information models. The proposed query language is intended for selecting, updating and deleting of data stored in Industry Foundation Classes models. Even though some partial solutions already have been suggested, none of them are open source, domain specific, platform independent and implemented at the same time. This paper provides an overview of existing approaches, conceptual sketches of the language in development and documents the current state of implementation as a prototype plugin developed for the open source model server platform bimserver.org. We report on the execution of example test-cases to show the general feasibility of the approach chosen.

B O O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

domain specific language
ifc
bim
building information model server


A prototype for an agent-based secure electronic marketplace including reputation-tracking mechanisms Software agents will play a crucial role in the coming digital economy, but their reliability and honesty cannot be guaranteed by technical security mechanisms, such as encryption of messages and digital signing of documents, and entities that can sanction fraudulent behavior in open networks are still in a rudimentary stage. This article describes a reputation mechanism that records previous cooperation behavior of participants in agent-based markets and conveys this information to other software agents, thereby influencing the future behavior of participants. The mechanism has been prototypically implemented in the Avalanche multiagent system. The deployment of this reputation mechanism will help to exclude fraudulent software agents from market participation.

O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O

agent-mediated electronic commerce
electronic marketplaces
reputation tracking