bluuebunny/crossref_metadata_2025 huggingface dataset:
An expert system for UNIX problem resolution
Authors: Mamone Salvatore
Published: January 2007

Many organizations regardless of their size and type, require an experienced systems professional staff to maintain their computer equipment and to help in resolving problems. Using an expert system can enable staff members to resolve many trivial problems, giving more time to the support staff for installation, performance monitoring, and solving complex problems. This article describes such an expert system, which was written to support an R & D organization. The version currently in use can recognize 40% of the known problems that staff members encounter. This percent is based on a historical record of previously logged problems. Although the system is written for a UNIX † and SUN environment, its structure could be used to implement a similar system for different hardware and software.
WebALPS
Authors: Smith S. W.
Published: January 2007

Web-based commerce is rife with scenarios where a party needs to trust properties of computation and data storage occurring at a remote machine, operated by a different party with different interests. In our WebALPS project, we have used off-the-shelf hardware and open source software to build
trusted co-servers
co-resident with Web servers, and bring the secure SSL channel all the way into these trusted co-servers. In this paper, we survey how this tool can be used to systematically address privacy and security issues in e-commerce.
Social ReGreT, a reputation model based on social relations
Authors: Sabater Jordi , Sierra Carles
Published: January 2007

Social network analysis has been used for a long time by sociologist as a mechanism to infer and explain social behaviours. Analysing social relations between individuals in a society using social network analysis techniques allows to identify a lot of features of that society that can be very valuable in an e-commerce environment. In this paper we describe how these techniques can be used to improve a reputation system and also how this system can be integrated with a negotiation model to increase the succes of negotiations.
Overview of some patterns for architecting and managing composite web services
Authors: Benatallah B. , Dumas M. , Fauvet M.-C. , Rabhi F. A. , Sheng Quan Z.
Published: January 2007

The composition of Web services has gained a considerable momentum as a paradigm for enabling Business-to-Business (B2B) Collaborations. Numerous technologies supporting this new paradigm are rapidly emerging, thereby creating a need for methodologies that bring these technologies together. The identification and documentation of relevant patterns, both at the analysis and design levels, is an important step in this direction.
A model for web services discovery with QoS
Authors: Ran Shuping
Published: January 2007

Web services technology has generated a lot interest, but its adoption rate has been slow. This paper discusses issues related to this slow take up and argues that quality of services is one of the contributing factors. The paper proposes a new Web services discovery model in which the functional and non-functional requirements (i.e. quality of services) are taken into account for the service discovery. The proposed model should give Web services consumers some confidence about the quality of service of the discovered Web services.
Statistics and data mining
Authors: Hand David J.
Published: January 2007

Statistics and data mining have much in common, but they also have differences. The nature of the two disciplines is examined, with emphasis on their similarities and differences.
Web usage mining
Authors: Srivastava Jaideep , Cooley Robert , Deshpande Mukund , Tan Pang-Ning
Published: January 2007

Web usage mining is the application of data mining techniques to discover usage patterns from Web data, in order to understand and better serve the needs of Web-based applications. Web usage mining consists of three phases, namely
preprocessing, pattern discovery
, and
pattern analysis
. This paper describes each of these phases in detail. Given its application potential, Web usage mining has seen a rapid increase in interest, from both the research and practice communities. This paper provides a detailed taxonomy of the work in this area, including research efforts as well as commercial offerings. An up-to-date survey of the existing work is also provided. Finally, a brief overview of the WebSIFT system as an example of a prototypical Web usage mining system is given.
KDD-99
Authors: Chaudhuri Surajit , Madigan David , Fayyad Usama
Published: January 2007

KDD-99 was the fifth conference in the KDD series attracting over 200 high quality submissions and almost 600 attendees. Here we describe some of the highlights of the technical program.
KDD-99 panel report
Authors: Kohavi Ronny , Sahami Mehran , Belcher Steve , Bozik Jim , Gerritsen Rob , Ono Ken , Pyle Dorian
Published: January 2007

At KDD-99, the panel on Integrating Data Mining into Vertical Solutions addressed a series of questions regarding future trends in industrial applications. Panelists were chosen to represent different viewpoints from a variety of industry segments, including data providers (Jim Bozik), horizontal and vertical tool providers (Ken Ono and Steve Belcher respectively), and data mining consultants (Rob Gerritsen and Dorian Pyle). Questions presented to the panelists included whether data mining companies should sell solutions or tools, who are the users of data mining, will data mining functionality be integrated into databases, do models need to be interpretable, what is the future of horizontal and vertical tool providers, and will industry-standard APls be adopted?
WEBKDD'99
Authors: Masand Brij , Spiliopoulou Myra
Published: January 2007

The WEBKDD'99 workshop on "Web Usage Analysis and User Profiling" took place at Aug. 15, 1999 under the auspices of the SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD'99). We report on the topics addressed in the workshop, the contributions and the discussions that took place in its framework.
Automatic synthesis of optimal invariant assertions
Authors: Cousot Patrick , Cousot Radhia
Published: January 2007

The problem of discovering invariant assertions of programs is explored in light of the fixpoint approach in the static analysis of programs, Cousot [1977a], Cousot[1977b].

In section 2 we establish the lattice theoric foundations upon which the synthesis of invariant assertions is based. We study the resolution of a fixpoint system of equations by Jacobi's successive approximations method. Under continuity hypothesis we show that any chaotic iterative method converges to the optimal solution. In section 3 we study the deductive semantics of programs. We show that a system of logical forward equations can be associated with a program using the predicate transformer rules which define the semantics of elementary instructions. The resolution of this system of semantic equations by chaotic iterations leads to the optimal invariants which exactly define the semantics of this program. Therefore these optimal invariants can be used for total correctness proofs (section 4). Next we show that usually a system of inequations is used as a substitute for the system of equations. Hence the solutions to this system of inequations are approximate invariants which can only be used for proofs of partial correctness (section 5). In section 6 we show that symbolic execution of programs consists in fact in solving the semantic equations associated with this program. The construction of the symbolic execution tree corresponds to the chaotic successive approximations method. Therefore symbolic execution permits optimal invariant assertions to be discovered provided that one can pass to the limit, that is consider infinite paths in the symbolic execution tree. Induction nrinciDles can be used for that purpose. In section 7 we show how difference equations can be utilized to discover the general term of the sequence of successive approximations so that optimal invariants are obtained by a mere passage to the limit. In section 8 we show that an approximation of the optimal solution to a fixpoint system of equations can be obtained by strengthening the term of a chaotic iteration sequence. This formalizes the synthesis of approximate invariants by heuristic methods. Various examples provide a helpful intuitive support to the technical sections.
Control requirements for the design of production system architectures
Authors: Rychener Michael D.
Published: January 2007

Programs in the artificial intelligence domain impose unusual requirements on control structures. Production systems are a control structure with promising attributes for building, generally intelligent systems with large knowledge bases. This paper presents examples to illustrate the unusual position taken by production systems on a number of control and pattern-matching issues. Examples are chosen to illustrate certain powerful features and to provide critical tests which might be used to evaluate the effectiveness of new designs.
Generalized procedure calling and content-directed invocation
Authors: Davis Randall
Published: January 2007

We suggest that the concept of a
strategy
can profitably be viewed as
knowledge about how to select from among a set of plausibly useful knowledge sources
, and explore the framework for knowledge organization which this implies. We describe
meta rules
, a means of encoding strategies that has been implemented in a program called TEIRESIAS, and explore their utility and contribution to problem solving performance.

Meta rules are also considered in the broader context of a tool for programming. We show that they can be considered a medium for expressing the criteria for retrieval of knowledge sources in a program, and hence can be used to define control regimes. The utility of this as a programming mechanism is considered.

Finally, we describe the technique of
content-directed invocation
used by meta rules, and consider its use as a way of implementing strategies. It is also considered in historical perspective as a knowledge source invocation technique, and its advantage over some existing mechanisms like goal-directed invocation is considered.

This work was supported in part by the Bureau of Health Sciences Research and Evaluation of HEW under Grant HS-01544 and by the Advanced Research Projects Agency under ARPA Order 2494. It was carried out on the SUMEX Computer System, supported by the NIH under Grant RR-00785. The views expressed are solely those of the author.
Automated derivation of program control structure from natural language program descriptions
Authors: Wile David , Balzer Robert , Goldman Neil
Published: January 2007

This paper describes a system which organizes a natural language description of a program into a conventional program control structure, as a part of a larger system for converting informal natural language program specifications into running programs. Analysis of the input program fragments using a model of a human “reader” of specifications has been found to be a very successful adjunct to conventional “planning” methodologies.

Natural language descriptions of programs can frequently be characterized as “rubble”—a very loosely organized set of almost independent description fragments [Schwartz]. Such specifications are often quite robust, due to a large degree of redundancy; they are also frequently quite concise, due to reliance on the readers' innate knowledge and their knowledge of the application domain. This paper discusses a paradigm for structuring the portion of “rubble” program descriptions which maps into conventional programming language control constructs and definition facilities.
The PSI Program Model Builder - synthesis of very high-level programs
Authors: McCune Brian P.
Published: January 2007

A system called the Program Model Builder (PMB) is being designed and implemented to perform the basic operations required to synthesize and modify programs. PMB plays a central role as one of the expert modules of the PSI (ψ) program synthesis system. PMB builds a complete and consistent program model from small chunks of program specification received from other (ψ) experts. PMB must deal with the fact that these program fragments often omit details and may be incomplete, ambiguous, inconsistent, nonspecific, and arbitrarily ordered. The initial version of PMB has successfully synthesized a few program models from fragments. This work includes the evolution of a very high-level program modelling language, the identification and codification of useful very high-level programming knowledge including equivalence transformations, and the implementation of a rule-based problem solving system embodying this knowledge.
The selection of efficient implementations for a high-level language
Authors: Kant Elaine
Published: January 2007

This paper considers the problem of identifying an efficient set of implementations for the abstract constructs in a very high level program description. LIBRA is a system that prunes and expands a tree of partially implemented program descriptions, given a set of refinement rules for generating the tree. Several sets of rules group, order, and select refinements. The analysis of the cost of a program (or program part) at any level of refinement is maintained for cost comparisons between different refinements, for bottleneck identification, and for branch and bound search.
Selection of representations for data structures
Authors: Rosenschein Stanley J. , Katz Shmuel M.
Published: January 2007

The process of selecting representations for data structures is considered. The model of the selection process we suggest is centered around a
base
of known abstract data structures and their representations. The abstract data structure for which a representation is required would not necessarily be in the base, but should be a combination of base data structures.

After describing this model of selection and its motivation, two aspects of the process are examined in more detail: a) The interaction with the user is treated by defining a language for the natural description of data structure requirements and b) two main types of combinations—hierarchical and cross-product—are analyzed, clarifying the relation between representations for component data structures and a representation for the combination.
A normal form for compiler testing
Authors: Samet Hanan
Published: January 2007

A formalism is presented for obtaining a normal form to be used in representing programs for compiler testing. Examples are used to motivate the features that must be considered when developing such a formalism. It is particularly suitable for heuristically optimized code and has been successfully used in a system for proving that programs written in a subset of LISP are correctly translated to assembly language.
A framework for modeling and optimization of prescient instruction prefetch
Authors: Aamodt Tor M. , Marcuello Pedro , Chow Paul , González Antonio , Hammarlund Per , Wang Hong , Shen John P.
Published: January 2007

This paper describes a framework for modeling macroscopic program behavior and applies it to optimizing prescient instruction prefetch -- novel technique that uses helper threads to improve single-threaded application performance by performing judicious and timely instruction prefetch. A helper thread is initiated when the main thread encounters a spawn point, and prefetches instructions starting at a distant target point. The target identifies a code region tending to incur I-cache misses that the main thread is likely to execute soon, even though intervening control flow may be unpredictable. The optimization of spawn-target pair selections is formulated by modeling program behavior as a Markov chain based on profile statistics. Execution paths are considered stochastic outcomes, and aspects of program behavior are summarized via path expression mappings. Mappings for computing reaching, and posteriori probability; path length mean, and variance; and expected path footprint are presented. These are used with Tarjan's fast path algorithm to efficiently estimate the benefit of spawn-target pair selections. Using this framework we propose a spawn-target pair selection algorithm for prescient instruction prefetch. This algorithm has been implemented, and evaluated for the Itanium Processor Family architecture. A limit study finds 4.8%to 17% speedups on an in-order simultaneous multithreading processor with eight contexts, over nextline and streaming I-prefetch for a set of benchmarks with high I-cache miss rates. The framework in this paper is potentially applicable to other thread speculation techniques.
Queueing systems with long-range dependent input process and subexponential service times
Authors: Xia Cathy H. , Liu Zhen
Published: January 2007

We analyze the asymptotic tail distribution of stationary waiting times and stationary virtual waiting times in a single-server queue with long-range dependent arrival process and subexponential service times. We investigate the joint impact of the long range dependency of the arrival process and of the tail distribution of the service times. We consider two traffic models that have been widely used to characterize the long-range dependence structure, namely, the M/G/
8
input model and the Fractional Gaussian Noise (FGN) model. We focus on the response times of the customers in a First-Come First-Serve (FCFS) queueing system, although the results carry through to the backlog distribution of the system with any arbitrary queueing discipline. When the arrival process is driven by an M/G/
8
input model we show that if the residual service time tail distribution

F
e

is lighter than the residual session duration

G
e

, then the stationary waiting time is dominated by the long-range dependence structure, which is determined by the residual session duration

G
e

. If the residual service time distribution

F
e

is heavier than the residual session duration

G
e

, then the tail distribution of the stationary waiting time is dominated by that of the residual service time. When the arrival process is modeled by an FGN, we show that the waiting time tail distribution is asymptotically equal to the tail distribution of the residual service time if the latter is asymptotically heavier than Weibull distribution with shape parameter 2-2H, where H is the Hurst parameter of the FGN. If, however, this residual service time is asymptotically lighter than Weibull distribution with shape parameter 2-2H, then the waiting time tail distribution is dominated by the dependence structure of the arrival process so that it is asymptotically equal to Weibull distribution with shape parameter 2-2H.
An algorithm for computing the mean response time of a single server queue with generalized on/off traffic arrivals
Authors: Galmés Sebastià , Puigjaner Ramon
Published: January 2007

In this paper, an exact solution for the response time distribution of a single server, infinite capacity, discrete-time queue is presented. This queue is fed by a flexible discrete-time arrival process, which follows an on/off evolution. A workload variable is associated with each arrival instant, which may correspond to the service demand generated by a single arrival, or represent the number of simultaneous arrivals (bulk arrivals). Accordingly, the analysis focuses on two types of queues: (On/Off)/G/1 and (Batch-On/Off)/D/1. For both cases, a decomposition approach is carried out, which divides the problem into two contributions: the response time experienced by single bursts in isolation, and the increase on the response time caused by the unfinished work that propagates from burst to burst. Particularly, the solution for the unfinished work is derived from a Wiener-Hopf factorization of random walks, which was already used in the analysis of discrete GI/G/1 queues. Compared to other related works, the procedure proposed in this paper is exact, valid for any traffic intensity and has no constraints on the distributions of the input random variables characterizing the process: duration of on and off periods, and workload. From the general solution, an efficient and robust iterative algorithm for computing the expected response time of both queues is developed, which can provide results at any desired precision. This algorithm is numerically evaluated for different types of input distributions and proved against simulation.
A hybrid systems modeling framework for fast and accurate simulation of data communication networks
Authors: Bohacek Stephan , Hespanha João P. , Lee Junsoo , Obraczka Katia
Published: January 2007

In this paper we present a general hybrid systems modeling framework to describe the flow of traffic in communication networks. To characterize network behavior, these models use averaging to continuously approximate discrete variables such as congestion window and queue size. Because averaging occurs over short time intervals, one still models discrete events such as the occurrence of a drop and the consequent reaction (e.g., congestion control). The proposed hybrid systems modeling framework fills the gap between packet-level and fluid-based models: by averaging discrete variables over a very short time scale (on the order of a round-trip time), our models are able to capture the dynamics of transient phenomena fairly accurately. This provides significant flexibility in modeling various congestion control mechanisms, different queuing policies, multicast transmission, etc. We validate our hybrid modeling methodology by comparing simulations of the hybrid models against packet-level simulations. We find that the probability density functions produced by ns-2 and our hybrid model match very closely with an

L
1

-distance of less than 1%. We also present complexity analysis of ns-2 and the hybrid model. These tests indicate that hybrid models are considerably faster.
Maximum and asymptotic UDP throughput under CHOKe
Authors: Wang Jiantao , Tang Ao , Low Steven H.
Published: January 2007

A recently proposed active queue management, CHOKe, aims to protect TCP from UDP flows. Simulations have shown that as UDP rate increases, its bandwidth share initially rises but eventually drops. We derive an approximate model of CHOKe and show that, provided the number of TCP flows is large, the UDP bandwidth share peaks at

(e+1)
-1
= 0.269

when the UDP input rate is slightly larger than the link capacity, and drops to zero as UDP input rate tends to infinity, regardless of the TCP algorithm.
Analysis of cycle stealing with switching cost
Authors: Osogami Takayuki , Harchol-Balter Mor , Scheller-Wolf Alan
Published: January 2007

We consider the scenario of two processors, each serving its own workload, where one of the processors (known as the "donor") can help the other processor (known as the "beneficiary") with its jobs, during times when the donor processor is idle. That is the beneficiary processor "steals idle cycles" from the donor processor. We assume that both donor jobs and beneficiary jobs may have generally-distributed service requirements. We assume that there is a switching cost required for the donor processor to start working on the beneficiary jobs, as well as a switching cost required for the donor processor to return to working on its own jobs. We also allow for threshold constraints, whereby the donor processor only initiates helping the beneficiary if both the donor is idle and the number of jobs at the beneficiary exceeds a certain threshold.We analyze the mean response time for the donor and beneficiary processors. Our analysis is approximate, but can be made as accurate as desired, and is validated via simulation. Results of the analysis illuminate several interesting principles with respect to the general benefits of cycle stealing and the design of cycle stealing policies.
Analysis of LAS scheduling for job size distributions with high variance
Authors: Rai Idris A. , Urvoy-Keller Guillaume , Biersack Ernst W.
Published: January 2007

Recent studies of Internet traffic have shown that flow size distributions often exhibit a high variability property in the sense that most of the flows are short and more than half of the total load is constituted by a small percentage of the largest flows. In the light of this observation, it is interesting to revisit scheduling policies that are known to favor small jobs in order to quantify the benefit for small and the penalty for large jobs. Among all scheduling policies that do not require knowledge of job size, the
least attained service
(LAS) scheduling policy is known to favor small jobs the most. We investigate the M/G/1/LAS queue for both, load
? < 1
and
? = 1
. Our analysis shows that for job size distributions with a high variability property, LAS favors short jobs with a negligible penalty to the few largest jobs, and that LAS achieves a mean response time over all jobs that is close to the mean response time achieved by SRPT.Finally, we implement LAS in the ns-2 network simulator to study its performance benefits for TCP flows. When LAS is used to schedule packets over the bottleneck link, more than 99% of the shortest flows experience smaller mean response times under LAS than under FIFO and only the largest jobs observe a negligible increase in response time. The benefit of using LAS as compared to FIFO is most pronounced at high load.
Efficient implementation of a statistics counter architecture
Authors: Ramabhadran Sriram , Varghese George
Published: January 2007

Internet routers and switches need to maintain millions of (e.g., per prefix) counters at up to OC-768 speeds that are essential for traffic engineering. Unfortunately, the speed requirements require the use of large amounts of expensive SRAM memory. Shah et al [1]introduced a cheaper statistics counter architecture that uses a much smaller amount of SRAM by using the SRAM as a cache together with a (cheap) backing DRAM that stores the complete counters. Counters in SRAM are periodically updated to the DRAM before they overflow under the control of a counter management algorithm. Shah et al [1] also devised a counter management algorithm called
LCF
that they prove uses an optimal amount of SRAM. Unfortunately, it is difficult to implement
LCF
at high speeds because it requires sorting to evict the largest counter in the SRAM. This paper removes this bottleneck in [1] by proposing a counter management algorithm called
LR(T)
(Largest Recent with thresh-old
T
) that avoids sorting by only keeping a bitmap that tracks counters that are larger than threshold
T
. This allows
LR(T)
to be practically realizable using only at most 2 bits extra per counter and a simple pipelined data structure. Despite this, we show through a formal analysis, that for a particular value of the threshold
T
, the
LR(T)
requires an optimal amount of SRAM, matching
LCF
. Further,we also describe an implementation, based on a novel data structure called aggregated bitmap, that allows the
LR(T)
algorithm to be realized at line rates.
Data cache locking for higher program predictability
Authors: Vera Xavier , Lisper Björn , Xue Jingling
Published: January 2007

Caches have become increasingly important with the widening gap between main memory and processor speeds. However, they are a source of unpredictability due to their characteristics, resulting in programs behaving in a different way than expected.Cache locking mechanisms adapt caches to the needs of real-time systems. Locking the cache is a solution that trades performance for predictability: at a cost of generally lower performance, the time of accessing the memory becomes predictable.This paper combines
compile-time cache analysis
with
data cache locking
to estimate the worst-case memory performance (WCMP) in a safe, tight and fast way. In order to get predictable cache behavior, we first lock the cache for those parts of the code where the static analysis fails. To minimize the performance degradation, our method loads the cache, if necessary, with data likely to be accessed.Experimental results show that this scheme is fully predictable, without compromising the performance of the transformed program. When compared to an algorithm that assumes compulsory misses when the state of the cache is unknown, our approach eliminates all overestimation for the set of benchmarks, giving an exact WCMP of the transformed program without any significant decrease in performance.
Analysis of TCP's computational energy cost for mobile computing
Authors: Wang Bokyung , Singh Suresh
Published: January 2007

In this paper we present results from a measurement study of TCP (Transmission Control Protocol) running over a wireless link. Our primary goal was on obtaining a breakdown of the computational energy cost of TCP at the sender and receiver (excluding radio energy costs) as a first step in developing techniques to reduce this cost in actual systems. We analyzed the energy consumption of TCP in FreeBSD 5 running on a wireless laptop. Our initial results showed that 60 - 70% of the energy cost (for transmission or reception) is accounted for by the Kernel -- NIC (Network Interface Card) copy operation. Of the remainder, 15% is accounted for in the copy operation from user space to kernel space with the remaining 15% being accounted for by TCP processing costs. We then further analyzed the TCP processing cost and determined the cost of computing checksums accounts for 20 -- 30% of TCP processing cost.
On the effectiveness of movement prediction to reduce energy consumption in wireless communication
Authors: Chakraborty Srijan , Yau David K. Y. , Lui John C. S.
Published: January 2007

Node movement can be exploited to reduce the energy consumption of wireless network communication. The strategy consists in delaying communication until a mobile node moves close to its
target
peer node, within an application-imposed deadline. We evaluate the performance of various heuristics that, based on the movement history of the mobile node, estimate an optimal time (in the sense of least energy use) of communication subject to the delay constraint. We evaluate the impact of node movement model, length of movement history maintained, allowable delay, single hop versus multiple hop communication, and size of data transfer on the energy consumption. We also present measurement results on an iPAQ pocket PC that quantify energy consumption in executing the prediction algorithms. Our results show that, with relatively simple and hence efficient prediction heuristics, energy savings in communication can significantly outweigh the energy expenses in executing the prediction algorithms.
Choosing an accurate network path model
Authors: Konrad Almudena , Joseph Anthony D.
Published: January 2007

We present a novel domain analysis methodology that enables network researchers to quickly select the most accurate modeling and analysis method or methods for a given wired or wireless network path and network characteristic of interest
e.g.
, delay, loss, or error process). Our approach includes two classical models, and two data preconditioning models developed in the
Tapas
project.
Symbolic computation of integrals by recurrence
Authors: Barnett Michael P.
Published: January 2007

We discuss (1) the construction of recurrence formulas for several types of indefinite and definite integral, (2) the conversion of some of the recurrence schemes to general closed formulas, (3) the mechanization of these processes, (4) "vectorized" recurrence, (5) "telescoped" recurrence, (6) the outperformance of present automatic integration software by the procedures that use our formulas, and (7) the interface between symbolic computation (computer algebra) and mathematical discourse.
Analysis of papers from twenty-five years of SIGIR conferences
Authors: Smeaton Alan F. , Keogh Gary , Gurrin Cathal , McDonald Kieran , Sødring Tom
Published: January 2007

As part of the celebration of twenty-five years of ACM SIGIR conferences we performed a content analysis of all papers published in the proceedings of SIGIR conferences, including those from 2002. From this we determined, using information retrieval approaches of course, which topics had come and gone over the last two and a half decades, and which topics are currently "hot". We also performed a co-authorship analysis among authors of the 853 SIGIR conference papers to determine which author is the most "central" in terms of a co-authorship graph and is our equivalent of Paul Erdös in Mathematics. In the first section we report on the content analysis, leading to our prediction as to the most topical paper likely to appear at SIGIR2003. In the second section we present details of our co-authorship analysis, revealing who is the "Christopher Lee" of SIGIR, and in the final section we give pointers to where readers who are SIGIR conference paper authors may find details of where they fit into the coauthorship graph.
Performance and scalability of mobile wireless base-station-oriented networks
Authors: Milner Stuart D. , Thakkar Sohil , Chandrashekar Karthikeyan , Chen Wei-Lun
Published: January 2007

This paper focuses on the performance and scalability of mobile, base-station-oriented wireless networks, which have been the subject of research and development projects sponsored by the Defense Advanced Research Projects Agency. The background and rationale for such networks is presented as well as performance and scalability analyses of their routing, mobility, and quality of service models. Using systems-oriented, large-scale discrete event simulation, both performance scalability and complexity scalability are analyzed. Performance scalability addresses the effect of network size on system performance. Complexity scalability, in this case, consists of communication complexity (i.e., amount of control information exchanged to create and maintain network connectivity). Results confirmed that the scalability of base station oriented networks using the routing, and mobility model, and the quality of service models enhanced performance, using over 2,000 fully dynamic hosts and routers.
Design and implementation of the HiperLan/2 protocol
Authors: Vasilakopoulou E. P. , Karastergios G. E. , Papadopoulos G. D.
Published: January 2007

In recent years, wireless communication systems have experienced an enormous development, leading to the emergence of various wireless networks standards. These standards are characterized by different properties, such as their coverage, data rates, mobility and QoS support. Among them the HiperLan/2 standard is distinguished of its performance, supporting the provision of high-speed integrated services. Its centralized Medium Access Control protocol though is the most critical and complex functional entity, enabling the management of the air-interface in real time and the efficient allocation of the bandwidth resources to the users. In this paper we will present the architecture and implementation of the HiperLan/2 MAC protocol, placing special emphasis on its timing requirements that define the hardware/software partitioning scheme of the developed system. The proposed architecture relieves the network upper layers of processing time critical events, enforcing the emergence of HiperLan/2 commercial products.
Adaptive medical information delivery
Authors: Francisco-Revilla Luis , Shipman Frank M.
Published: January 2007

Medical information delivery for users with different levels of expertise will be required for the manned mission to Mars due to limited potential for communication with Earth. The Mars Medical Assistant uses a combination of user, situation, and task models to create virtual hypertext structures by piecing together medical "information components." Determination of which information components will be shown to the user and in what order is based on both the semantic content of the component and the cognitive characteristics of the component's media type. The medical assistant currently supports three tasks: 1) describing medical procedures, 2) aiding diagnosis, and 3) providing information on health concerns.
A translating computer interface for a network of heterogeneous interactive information retrieval systems
Authors: Marcus Richard S.
Published: January 2007

The need for a network of heterogeneous interactive bibliographic information retrieval systems is projected from the facts of wide acceptance and growing demand for these systems and the limitations of their use caused by limited online data base size. Because of the established characters of the different I-R systems and unlikelihood that a standardized I-R system leading directly to the ultimate uniform network will soon be generally adopted, we propose an intermediate solution in which computer interfaces would provide the networking capability by translating and converting among the diverse languages and data bases of existing systems.We have begun work on such a network in which the computer interface is based on the concept of a common language for commands, indexing vocabularies, and data base structures. In particular, the common language for commands and data base structures is based on identifying the basic or primitive I-R functions and bibliographic data base elements. The conversion among indexing vocabularies is based on the concept of a Master Index and Thesaurus containing the conglomerate thesaurus information from the separate data bases. In addition, the phrase decomposition and stemming of the individual words in the search request and subject index phrases are used as further techniques for automated conversion among diverse vocabularies. An initial experimental interface is described which interconnects the M.I.T. Intrex system, the MEDLINE retrieval system, and the TYMNET computer network using the ARPANET Terminal Interface Processors for intercomputer communication.
Specifying queries as relational expressions
Authors: Boyce R. F. , Chamberlin D. D. , Hammer M. M. , King W. F.
Published: January 2007

SQUARE (Specifying Queries As Relational Expressions) is a set oriented data sublanguage for expressing queries (access, modification, insertion, and deletion) to a data base consisting of a collection of time-varying relations. The language mimics how people use relations or tables to obtain information. It does not require the sophisticated mathematical machinery of the predicate calculus (bound variables, quantifiers, etc.) in order to express simple references to tables. However, the language has been shown to be complete, i.e., any query expressible in the predicate calculus is expressible in SQUARE.
Computer graphics for the blind
Authors: Wefold Harold E.
Published: January 2007

Recent experience at Vitro Laboratories points to automated Braille graphics as an effective analytical tool for blind persons. The writer has developed a generalized system in which plot commands are captured on a "Macro tape". The plot thus defined can be placed on a pen plotter, electrostatic printer, CRT or line-printer without reprogramming. An option to the line-printer module allows lines to be displayed with dots and symbols to be displayed in Braille. An elastic strap, which fits on any printer, causes the dots to be raised. With automatic rescaling and scissoring the plots can be blown up to any size. This system is being regularly used to make plots of engineering data for a blind engineer at Vitro, with extensive savings in analysis time. Maps, mathematical curves, block diagrams, and perspective plots have also been generated which show great potential for educational purposes.
A punched-card reader for the blind programmer with synthesized voice output
Authors: Swail James C. , Suen Ching Y.
Published: January 2007

Through digital conversion of codes, a punched-card reader with synthesized voice output has been implemented. As soon as a column of holes passes the photocells, the machine will automatically pronounce the character.
A microprocessor environmental controller for quadriplegics
Authors: Bojanowski T. , Bloch R. , Milner M.
Published: January 2007

An environmental controller has been designed using consumer available components. Its flexibility, versatility, and reduced cost, are a direct result of using an isometric joystick, a microprocessor and software package in a configuration that lends itself very readily to change.
A system for transcribing mathematics into braille
Authors: Meekel J. , Truquet M.
Published: January 2007

Transcribing Mathematical documents into braille requires a knowledge and a mastery of mathematical braille which is very complex. Consequently editions of scientific books are very few in this area. This paper describes a system for transcribing automatically mathematical text into braille.
Pen-based, mobile decision support in healthcare
Authors: Shiffman Richard N. , Karras Bryant T. , Nath Sujai , Engles-Horton Laura , Corb Geoffrey J.
Published: January 2007

The use of computers has become well established throughout the business enterprise; but computer usage within the health care sector has lagged, particularly for automation of interactions between individual clinicians and their patients. A number of factors have contributed to this including difficulties in representing medical knowledge in computer-processible formats, the limited application of standards for data recording and transmission, and problems in human-computer interaction.A major obstacle to the use of computers in medicine has been the stationary nature of desktop computers. Most clinicians are mobile knowledge workers who need access to information across a wide variety of settings: in offices, exam rooms, emergency departments, hospitals, nursing homes and at home. Within each setting, there is concern that a large box on the consultation desk may interfere with communication between clinicians and patients. Moreover, many physicians do not have keyboard skills. Even for those who can type, keyboard data entry---concomitant with interviewing and examination-- is difficult. To overcome these obstacles, our group at the Yale Center for Medical Informatics has developed systems that operate on small, mobile platforms and accept pen-based data entry.We recognized early on that systems would have to be integrated tightly with clinical workflow and provide benefits to offset the inconvenience associated with their use. Clinical workflow refers to the complex interacting tasks performed by clinicians as they go about their daily work and to the corresponding information flows that are generated. A particular interest has been in providing clinical decision support at the point-of-care. We have extracted knowledge from evidence-based clinical practice guidelines and embedded it in mobile, pen-based systems that inform decision making by clinicians.
Glaucoma screening using data mining techniques
Authors: Liu X.
Published: January 2007

Working with Moorfields Eye Hospital, Central Middlesex Hospital, Institute of Ophthalmology and Henri Mondor Hospital, we have developed a number of real-world applications using data mining and intelligent data analysis techniques. These have led not only to novel research results, but also successful fielded applications, e.g. in hospital, GP clinic, and large-scale field investigations.
Gait malfunction identification and classification
Authors: Merkl Dieter
Published: January 2007

Based on data recorded with ground reaction force measurement platforms we are working towards a tool for human gait malfunction identification. The data is recorded with patients during their stay at an Austrian rehabilitation centre after injuries to their locomotive system. Issues of interest are the representation of ground reaction force data for subsequent identification of gait malfunctions and tools for the identification and classification of gait malfunctions. So far we were primarily interested in evaluating different architectures of artificial neural networks to perform that task.
Data mining of prenatal data
Authors: Goodwin Linda
Published: January 2007

Comparing inductive machine learning with neural nets and traditional statistical techniques for 'best' predictors of women at risk for PRETERM BIRTH. Preterm babies having higher mortality and morbidity outcomes and often cost in excess of $1 million in the first year of life. We're mining 10 years of prenatal data for possible patterns of preterm birth risk.
Knowledge discovery in distributed cardiac imagebases
Authors: Ezquerra Norberto
Published: January 2007

Based on knowledge discovery and data mining methodologies, we present research with the overall objective of developing a clinically useful, computer based system to aid in accurate and reliable assessment of coronary artery disease (CAD). The emphasis is placed on designing, implementing and testing a methodology for "mining" distributed clinical databases in order to discover potential associations and interdependencies that may be imbedded in geographically dispersed databases. Subsequently, all newly discovered (and validated) knowledge will be used to enrich a knowledge base designed to interpret both myocardial perfusion imagery and other relevant patient information. The validated knowledge base will ultimately be integrated into an interactive and visual consultation framework, which will be placed in the context of Internet-based communications to provide widespread access to remote users.
Multi-relational data mining
Authors: Džeroski Sašo
Published: January 2007

Data mining algorithms look for patterns in data. While most existing data mining approaches look for patterns in a single data table, multi-relational data mining (MRDM) approaches look for patterns that involve multiple tables (relations) from a relational database. In recent years, the most common types of patterns and approaches considered in data mining have been extended to the multi-relational case and MRDM now encompasses multi-relational (MR) association rule discovery, MR decision trees and MR distance-based methods, among others. MRDM approaches have been successfully applied to a number of problems in a variety of areas, most notably in the area of bioinformatics. This article provides a brief introduction to MRDM, while the remainder of this special issue treats in detail advanced research topics at the frontiers of MRDM.
Abstraction in databases
Authors: McLeod Dennis , Smith John Miles
Published: January 2007

This paper surveys current research and practice concerning abstraction in database systems. Classical and semantic database models are reviewed and emphasized, as fundamental database abstraction mechanisms.
Data abstraction from a programming language viewpoint
Authors: Rowe Lawrence A.
Published: January 2007

This paper traces the development of data abstraction concepts in programming languages. A data abstraction, or abstract data type, describes a collection of abstract entities and operations on the entities. A program which uses a data abstraction can access or modify the entities only through the abstract operations.

Specific research topics discussed in the paper include: the role of type in a programming language, the formal specification of the semantics of a data abstraction, data abstraction language construct design issues, type hierarchies, and type-checking.