bluuebunny/crossref_metadata_2025 huggingface dataset:
TRANSFER BETWEEN SIMILAR MENU SYSTEMS
Authors: Foltz Peter W. , Davies Susan E. , Polson Peter G. , Kieras David
Published: January 2007

As technology changes, it has become common to develop now generations of existing software to reflect these advances. The focus of this research is how changes in the user/computer dialogue structure will affect the performance of users who are familiar with an earlier version of the product. In the case of menu-based systems, changes in new releases frequently involve modification of the underlying menu structure (e.g., IBM DisplayWrite series, DBaseIII -DBaseIII+). We investigated whether changing the semantics and structure of a popular menu-driven word-processor would permit transfer of existing knowledge of the word-processor to the new version.
A NATURAL LANGUAGE SHELL
Authors: Matthews Manton M.
Published: January 2007

This paper describes a natural language interface, that models users and maintains a knowledge base of how users are using the system. The system is developed under Unix using a combination of Prolog and C code. The natural language processing part is being implemented in UNSW Prolog with extensions to facilitate efficient processing of dictionaries and frame hierarchies.
SUBLIMINAL PRESENTATION OF HELP SCREENS ON A MICROCOMPUTER
Authors: Wallace F. Layne , Flanery J. Michael
Published: January 2007

This study was undertaken to determine if subliminally presented HELP screens would allow subjects to learn a new text editor faster than subjects who received no subliminal assistance. Three different subliminal screens were presented: HELP screen, screen of garbage text, and a blank screen. Two subliminal screen presentation schedules were employed: fixed interval and fixed ratio. Significant differences were found among the three screen contents regarding the number of commands issued between each request for help and the amount of time between each request for help. Post hoc examination showed that the group receiving subliminal HELP screens issued more commands between help requests and took more time between requests for help than the group receiving garbage subliminal presentations. While no differences were found among groups with regard to the percentage of commands that were help requests, a trend consistent with the above findings was noted.
A comment on “A note on Einstein metrics”
Authors: Schrüfer Eberhard
Published: January 2007

In a recent note, Nielsen and Pedersen [1] reported how they verified some solutions of Einstein's field equations with the help of REDUCE. They used a program which is contained in the standard REDUCE [2] testfile and which was written by Barton and Fitch.
Comparison of polynomial-oriented computer algebra systems
Authors: Lewis Robert H. , Wester Michael
Published: January 2007

Exact symbolic computation with polynomials and matrices over polynomial rings has wide applicability to many fields [Hereman96, Lewis99]. By "exact symbolic", we mean computation with polynomials whose coefficients are integers (of any size), rational numbers, or from finite fields, as opposed to coefficients that are "floats" of a certain precision. Such computation is part of most computer algebra (CA) systems. Over the last dozen years, several large CA systems have become widely available, such as Axiom, Derive, Macsyma, Maple, Mathematica and Reduce. They tend to have great breadth, be produced by profit-making companies, and be relatively expensive, at least for a full blown non-student version. However, most if not all of these systems have difficulty computing with the polynomials and matrices that arise in actual research. Real problems tend to produce large polynomials and large matrices that the general CA systems cannot handle [Lewis99].In the last few years, several smaller CA systems focused on polynomials have been produced at universities by individual researchers or small teams. They run on Macs, PCs and workstations. They are freeware or shareware. Several claim to be much more efficient than the large systems at exact polynomial computations. The list of these systems includes CoCoA, Fermat, MuPAD, Pari-Gp and Singular [CoCoA, Fermat, MuPAD, Pari-Gp, Singular].In this paper, we compare these small systems to each other and to two of the large systems (Magma and Maple) on a set of problems involving exact symbolic computation with polynomials and matrices. The problems here involve:• the ground rings
Z, Q, Z
/p and other finite fields• basic arithmetic of polynomials over the ground ring• basic arithmetic of rational functions over the ground ring• polynomial evaluation (substitution)• matrix normal forms• determinants and characteristic polynomials• GCDs of multivariate polynomials• resultants
Interactive mining and knowledge reuse for the closed-itemset incremental-mining problem
Authors: Dumitriu Luminita
Published: January 2007

Using concept lattices as a theoretical background for finding association rules [11] has led to designing algorithms like Charm [10], Close [7] or Closet [8]. While they are considered as extremely appropriate when finding concepts for association rules, due to the smaller amount of results, they do not cover a certain area of significant results, namely the pseudo-intents that form the base for global implications. We have proposed an approach that, besides finding all proper partial implications, also finds the pseudo-intents. The way our algorithm is devised, it allows certain important operations on concept lattices, like adding or extracting items, meaning we can reuse previously found results. It is a well-known fact that mining association rules may lead to a large amount of results. Since, the mining results are meant to be understood by the user, we have come to the conclusion that he will benefit more from starting small, with some of the items in the data base, understand a small amount of results, and then add items receiving only the extra-results. This way the number of human interventions during the "full" mining process is increased and the process becomes user-driven.
BIOKDD01
Authors: Zaki Mohammed J. , Wang Jason T. L. , Toivonen Hannu T. T.
Published: January 2007

In this report we provide a summary of the BIOKDD01 Workshop on Data Mining in Bioinformatics, held in conjunction with the 7th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, August 26, 2001 at San Francisco, California, USA.
When and how to subsample
Authors: Domingos Pedro
Published: January 2007

Databases in the terabyte range are now common. In many domains, mining all the data available in reasonable time is already beyond the reach of current systems. Yet the size of databases continues to grow rapidly. Is subsampling unavoidable? Or should it be avoided at all costs? If we subsample, what is the best way to do it? What issues must be taken into account? The KDD-2001 Panel on When and How to Subsample addressed these and related questions, with the twin goals of developing practical guidelines and identifying key research issues. It was chaired by Pedro Domingos (University of Washington), and the participants were Surajit Chaudhuri (Microsoft Research), David Jensen (University of Massachusetts at Amherst), Ronny Kohavi (Blue Martini), and Foster Provost (New York University). Below is each panelist's summary of his position.
Towards long pattern generation in dense databases
Authors: Aggarwal Charu C.
Published: January 2007

This paper discusses the problem of long pattern generation in dense databases. In recent years, there has been an increase of interest in techniques for maximal pattern generation. We present a survey of this class of methods for long pattern generation which differ considerably from the level-wise approach of traditional methods. Many of these techniques are rooted in combinatorial tricks which can be applied only when the generation of frequent patterns is not forced to be level wise. We present an overview of the different kinds of methods which can be used in order to improve the counting and search space exploration methods for long patterns.
Report on the workshop on research issues in data mining and knowledge discovery workshop (DMKD 2001)
Authors: Bayardo Roberto , Gehrke Johannes E.
Published: January 2007

This short article summarizes the program of the Sixth Workshop on Research Issues in Data Mining and Knowledge Discovery Workshop (DMKD 2001).
KDnuggets interview with Jesus Mena
Authors: Piatetsky-Shapiro Gregory
Published: January 2007

The KDnuggets newsletter has a new section of interviews with leaders in the field. This article presents the interview with Jesus Mena, CEO of WebMiner.
On maximizing service-level-agreement profits
Authors: Liu Zhen , Squillante Mark S. , Wolf Joel L.
Published: January 2007

We present an initial study of a methodology for maximizing profits in a general class of e-commerce environments under a cost model in which revenues are generated when QoS guarantees are satisfied and penalties are incurred otherwise. The QoS guarantees are based on multiclass SLAs between service providers and their clients, which include the tail distributions of the per-class response times. Our approach consists of formulating the resulting optimization problem as a network flow model with a separable set of concave objective function summands based on derived queueing-theoretic formulas. This problem is then solved in a very efficient manner via a fixed-point iteration.
Cascade compilation revisited
Authors: Stern Ted , Grimwood Daniel
Published: January 2007

The problem of cascade recompilation in large modern Fortran projects is well known --- a non-interface related change of a module can cause recompilation in the entire chain of dependents of that module, even when the compiler would not require it [1]. Furthermore, it is not trivial to set up the proper dependency relationship among modules and their dependents. See [2-5] for examples of various ways of setting up these dependencies.Solutions proposed up until now have not dealt comprehensively with the issue of a module file not undergoing any substantive change during source file recompilation or, if they did, they relied on the assumption that there is only one module definition per text file, and further that the generated module file has the same basename the source file. None of these assumptions may be true in practice.Furthermore, the issue of parallel builds is usually not addressed. For very large projects (
O
(1-10K) source files), parallel builds can decrease compilation time by an order of magnitude.With a moderate amount of scripting (in either Perl or Korn-shell), and using the capabilities of more recent versions of GNU Make [6,7] it is possible to create makefiles that handle complicated cross-dependencies nearly automatically, and reduce recompilation time substantially.
A case for mobility support with temporary home agents
Authors: Zheng Rong , Ge Ye , Hou Jennifer C. , Thuel Sandy R.
Published: January 2007

The Mobile IP standard for mobility management on the Internet enables transparent communication between mobile hosts (MHs) and their correspondent hosts (CHs). However, it suffers from triangular routing and prolonged handoff latency problems. Solutions such as route optimization and micro-mobility protocols either solve these problems partially or require costly modifications to the CHs. In this paper, we propose to use
temporary home agent
(TA) to address both problems without requiring any special support on CHs. TA exploits the locality of user movement observed in recent studies for PCS and wireless data networks. It does so by dynamically selecting a Mobile IP home agent based on the location of the user. The TA allocates a temporary home address,
THAddr
to the MH, which the MH may use as its source address. The underlying objective is to shorten the distance between a MH and its home agent, which is a critical factor in reducing handoff latency and improving routing efficiency. Our scheme is shown to outperform Mobile IP and is comparable to route optimization (RO) through both quantitative analysis and
ns
simulations. While our approach focus on improving the performance for sessions that are initiated by the MH, methods for optimizing traffic handling for sessions initiated by CHs are discussed.
Modeling and analysis of dynamic coscheduling in parallel and distributed environments
Authors: Squillante Mark S. , Zhang Yanyong , Sivasubramaniam Anand , Gautam Natarajan , Franke Hubertus , Moreira Jose
Published: January 2007

Scheduling in large-scale parallel systems has been and continues to be an important and challenging research problem. Several key factors, including the increasing use of off-the-shelf clusters of workstations to build such parallel systems, have resulted in the emergence of a new class of scheduling strategies, broadly referred to as dynamic coscheduling. Unfortunately, the size of both the design and performance spaces of these emerging scheduling strategies is quite large, due in part to the numerous dynamic interactions among the different components of the parallel computing environment as well as the wide range of applications and systems that can comprise the parallel environment. This in turn makes it difficult to fully explore the benefits and limitations of the various proposed dynamic coscheduling approaches for large-scale systems solely with the use of simulation and/or experimentation.To gain a better understanding of the fundamental properties of different dynamic coscheduling methods, we formulate a general mathematical model of this class of scheduling strategies within a unified framework that allows us to investigate a wide range of parallel environments. We derive a matrix-analytic analysis based on a stochastic decomposition and a fixed-point iteration. A large number of numerical experiments are performed in part to examine the accuracy of our approach. These numerical results are in excellent agreement with detailed simulation results. Our mathematical model and analysis is then used to explore several fundamental design and performance tradeoffs associated with the class of dynamic coscheduling policies across a broad spectrum of parallel computing environments.
Symbiotic jobscheduling with priorities for a simultaneous multithreading processor
Authors: Snavely Allan , Tullsen Dean M. , Voelker Geoff
Published: January 2007

Simultaneous Multithreading machines benefit from jobscheduling software that monitors how well coscheduled jobs share CPU resources, and coschedules jobs that interact well to make more efficient use of those resources. As a result, informed coscheduling can yield significant performance gains over naive schedulers. However, prior work on coscheduling focused on equal-priority job mixes, which is an unrealistic assumption for modern operating systems.This paper demonstrates that a scheduler for an SMT machine can both satisfy process priorities and symbiotically schedule low and high priority threads to increase system throughput. Naive priority schedulers dedicate the machine to high priority jobs to meet priority goals, and as a result decrease opportunities for increased performance from multithreading and coscheduling. More informed schedulers, however, can dynamically monitor the progress and resource utilization of jobs on the machine, and dynamically adjust the degree of multithreading to improve performance while still meeting priority goals.Using detailed simulation of an SMT architecture, we introduce and evaluate a series of five software and hardware-assisted priority schedulers. Overall, our results indicate that coscheduling priority jobs can significantly increase system throughput by as much as 40%, and that (1) the benefit depends upon the relative priority of the coscheduled jobs, and (2) more sophisticated schedulers are more effective when the differences in priorities are greatest. We show that our priority schedulers can decrease average turnaround times for a random jobmix by as much as 33%.
Full-system timing-first simulation
Authors: Mauer Carl J. , Hill Mark D. , Wood David A.
Published: January 2007

Computer system designers often evaluate future design alternatives with detailed simulators that strive for
functional fidelity
(to execute relevant workloads) and
performance fidelity
(to rank design alternatives). Trends toward multi-threaded architectures, more complex micro-architectures, and richer workloads, make authoring detailed simulators increasingly difficult. To manage simulator complexity, this paper advocates decoupled simulator organizations that separate functional and performance concerns. Furthermore, we define an approach, called
timing-first simulation,
that uses an augmented timing simulator to execute instructions important to performance in conjunction with a functional simulator to insure correctness. This design simplifies software development, leverages existing simulators, and can model micro-architecture timing in detail.We describe the timing-first organization and our experiences implementing TFsim, a full-system multiprocessor performance simulator. TFsim models a pipelined, out-of-order micro-architecture in detail, was developed in less than one person-year, and performs competitively with previously-published simulators. TFsim's timing simulator implements dynamically common instructions (99.99% of them), while avoiding the vast and exacting implementation efforts necessary to run unmodified commercial operating systems and workloads. Virtutech Simics, a full-system functional simulator, checks and corrects the timing simulator's execution, contributing 18-36% to the overall run-time. TFsim's mostly correct functional implementation introduces a worst-case performance error of 4.8% for our commercial workloads. Some additional simulator performance is gained by verifying functional correctness less often, at the cost of some additional performance error.
Error-free garbage collection traces
Authors: Hertz Matthew , Blackburn Stephen M , Moss J Eliot B , McKinley Kathryn S. , Stefanović Darko
Published: January 2007

Programmers are writing a large and rapidly growing number of programs in object-oriented languages such as Java that require garbage collection (GC). To explore the design and evaluation of GC algorithms quickly, researchers are using simulation based on traces of object allocation and lifetime behavior. The
brute force
method generates perfect traces using a whole-heap GC at every potential GC point in the program. Because this process is prohibitively expensive, researchers often use
granulated
traces by collecting only periodically, e.g., every 32K bytes of allocation.We extend the state of the art for simulating GC algorithms in two ways. First, we present a systematic methodology and results on the effects of trace granularity for a variety of copying GC algorithms. We show that trace granularity often distorts GC performance results compared with perfect traces, and that some GC algorithms are more sensitive to this effect than others. Second, we introduce and measure the performance of a new precise algorithm for generating GC traces which is over 800 times faster than the brute force method. Our algorithm, called Merlin, frequently timestamps objects and later uses the timestamps of dead objects to reconstruct precisely when they died. It performs only periodic garbage collections and achieves high accuracy at low cost, eliminating any reason to use granulated traces.
Quality of service evaluations of multicast streaming protocols
Authors: Tan Haonan , Eager Derek L. , Vernon Mary K. , Guo Hongfei
Published: January 2007

Recently proposed scalable on-demand streaming protocols have previously been evaluated using a system cost measure termed the "required server bandwidth". For the scalable protocols that provide immediate service to each client when the server is not overloaded, this paper develops simple analytic models to evaluate two client-oriented quality of service metrics, namely (1) the mean client waiting time in systems where clients are willing to wait if a (well-provisioned) server is temporarily overloaded, and (2) the fraction of clients who balk (i.e., leave without receiving their requested media content) in systems where the clients will tolerate no or only very low service delays during a temporary overload. The models include novel approximate MVA techniques that appear to extend the range of applicability of customized AMVA to include questions focussed on state probabilities rather than on mean values, and to systems in which the operating points of interest do not include substantial client queues. For example, the new AMVA models accurately estimate the server bandwidth needed to achieve a balking rate as low as one in ten thousand. The analytic models can easily be applied to determine the server bandwidth needed for a given number of media files, anticipated total client request rate and file access frequencies, and target balking rate or mean wait. Results show that (a) scalable media servers that are configured with the "required server bandwidth" defined in previous work have low mean wait but may have unacceptably high client balking rates (i.e., greater than one in twenty), (b) for high to moderate client load, only a 10 - 50% increase in the previously defined required server bandwidth is needed to achieve a very low balking rate (e.g., one in ten thousand), and (c) media server performance (either mean wait or balking rate) degrades rapidly if the actual client load is more than 10% greater than the anticipated load.
Characterizing user behavior and network performance in a public wireless LAN
Authors: Balachandran Anand , Voelker Geoffrey M. , Bahl Paramvir , Rangan P. Venkat
Published: January 2007

This paper presents and analyzes user behavior and network performance in a public-area wireless network using a workload captured at a well-attended ACM conference. The goals of our study are: (1) to extend our understanding of wireless user behavior and wireless network performance; (2) to characterize wireless users in terms of a parameterized model for use with analytic and simulation studies involving wireless LAN traffic; and (3) to apply our workload analysis results to issues in wireless network deployment, such as capacity planning, and potential network optimizations, such as algorithms for load balancing across multiple access points (APs) in a wireless network.
Limits of wide-area thin-client computing
Authors: Lai Albert , Nieh Jason
Published: January 2007

While many application service providers have proposed using thin-client computing to deliver computational services over the Internet, little work has been done to evaluate the effectiveness of thin-client computing in a wide-area network. To assess the potential of thin-client computing in the context of future commodity high-bandwidth Internet access, we have used a novel, non-invasive slow-motion benchmarking technique to evaluate the performance of several popular thin-client computing platforms in delivering computational services cross-country over Internet2. Our results show that using thin-client computing in a wide-area network environment can deliver acceptable performance over Internet2, even when client and server are located thousands of miles apart on opposite ends of the country. However, performance varies widely among thin-client platforms and not all platforms are suitable for this environment. While many thin-client systems are touted as being bandwidth efficient, we show that network latency is often the key factor in limiting wide-area thin-client performance. Furthermore, we show that the same techniques used to improve bandwidth efficiency often result in worse overall performance in wide-area networks. We characterize and analyze the different design choices in the various thin-client platforms and explain which of these choices should be selected for supporting wide-area computing services.
Dynamic statistical profiling of communication activity in distributed applications
Authors: Vetter Jeffrey
Published: January 2007

Performance analysis of communication activity for a terascale application with traditional message tracing can be overwhelming in terms of overhead, perturbation, and storage. We propose a novel alternative that enables dynamic statistical profiling of an application's communication activity using message sampling. We have implemented an operational prototype, named P
HOTON
, and our evidence shows that this new approach can provide an accurate, low-overhead, tractable alternative for performance analysis of communication activity. P
HOTON
consists of two components: a Message Passing Interface (MPI) profiling layer that implements sampling and analysis, and a modified MPI runtime that appends a small but necessary amount of information to individual messages. More importantly, this alternative enables an assortment of runtime analysis techniques so that, in contrast to post-mortem, trace-based techniques, the raw performance data can be jettisoned immediately after analysis. Our investigation shows that message sampling can reduce overhead to imperceptible levels for many applications. Experiments on several applications demonstrate the viability of this approach. For example, with one application, our technique reduced the analysis overhead from 154% for traditional tracing to 6% for statistical profiling. We also evaluate different sampling techniques in this framework. The coverage of the sample space provided by purely random sampling is superior to counter- and timer-based sampling. Also, P
HOTON
's design reveals that frugal modifications to the MPI runtime system could facilitate such techniques on production computing systems, and it suggests that this sampling technique could execute continuously for long-running applications.
Workload based optimization of probe-based storage
Authors: Sivan-Zimet Miriam , Madhyastha Tara M.
Published: January 2007

The performance gap between microprocessors and secondary storage is still a limitation in today's systems. Academia and industry are developing new technologies to overcome this gap, such as improved read-write head technology and higher storage densities. One promising new technology is probe-based storage[1]. Characteristics of probe-based storage include small size, high density, high parallelism, low power consumption, and rectilinear motion. We have created a probe-based storage simulation model, configurable to different design points, and identify its sensitivity to various parameters.
Application level traffic measurements for capacity engineering
Authors: Chandramouli Y. , Neidhardt Arnold
Published: January 2007

In general, the traffic characteristics of the individual applications that constitute the aggregate traffic on a network can be important for capacity engineering. In this paper, we demonstrate based on mathematical analysis the value of application specific measurements even when there is no service differentiation. In other words, under certain assumptions, we obtain the result that errors in engineering can occur, and in particular, under-engineering can occur when traffic characteristics of individual applications are ignored. The assumptions are that the individual applications can be modeled adequately as Fractional Brownian Motions and that measurements are available only at relatively coarse time scales. The results in this paper emphasize the value of collecting fine-grained traffic measurements.
Internet stream size distributions
Authors: Brownlee Nevil , claffy kc
Published: January 2007

We present and discuss stream size and lifetime distributions for web and non-web TCP traffic on a campus OC12 link at UC San Diego. The distributions are stable over long periods, and show that on this link only 3% of the streams last longer than one minute, and that only about 0.5% of them are bigger than 100 kBytes. Although there are large streams (elephants) on this link, the bulk of its traffic is composed of many small streams (mice).
Can large disk built-in caches really improve system performance?
Authors: Zhu Yingwu , Hu Yiming
Published: January 2007

Via detailed file system and disk system simulation, we examine the impact of disk built-in caches on the system performance. Our results indicate that the current trend of using large built-in caches is unnecessary and a waste of money and power for most users. Disk manufacturers could use much smaller built-in caches to reduce the cost as well as power-consumption, without affecting performance.
Solution properties and convergence of an approximate mean value analysis algorithm
Authors: Sevcik Kenneth C. , Wang Hai
Published: January 2007

We present the solution properties and convergence results of an approximate Mean Value Analysis (MVA) algorithm, the Queue Line (QL) algorithm, for solving separable queueing networks. We formally prove that the QL algorithm is always more accurate than, and yet has the same computational complexity as the Bard-Schweitzer Proportional Estimation algorithm, the most popular approximate MVA algorithm for solving this type of queueing networks.
A performance study of Bistro, a scalable upload architecture
Authors: Cheng William C. , Chou Cheng-Fu , Golubchik Leana , Khuller Samir
Published: January 2007

Hot spots are a major obstacle to achieving scalability in the Internet. We have observed that the existence of hot spots in
upload
applications (whose examples include submission of income tax forms and conference paper submission) is largely due to approaching deadlines. The hot spot is exacerbated by the long transfer times. To address this problem, we proposed
Bistro
, a framework for building scalable wide-area upload applications, where we employ intermediaries, termed
bistros
, for improving the efficiency and scalability of uploads. Consequently, appropriate assignment of clients to
bistros
has a significant effect on the performance of upload applications and thus constitutes an important research problem. Therefore, in this paper we focus on the assignment of clients to
bistros
problem and present a performance study which demonstrates the potential performance gains of the
Bistro
framework.
Multiple-queue backfilling scheduling with priorities and reservations for parallel systems
Authors: Lawson Barry G. , Smirni Evgenia
Published: January 2007

We describe a new, non-FCFS policy to schedule parallel jobs on systems that may be part of a computational grid. Our algorithm continuously monitors the system (i.e., intensity of incoming jobs and variability of their resource demands) and continuously adapts its scheduling parameters to sudden workload fluctuations. The proposed policy is based on backfilling which permits job rearrangement in the waiting queue. By exploiting otherwise idle processors, this rearrangement reduces fragmentation of system resources, thereby providing higher system utilization. We propose to maintain multiple job queues that effectively separate jobs according to their projected execution time. Our policy supports different job priority classes as well as job reservations, making it appropriate for scheduling jobs on parallel systems that are part of a computational grid. Detailed performance comparisons via simulation using traces from the Parallel Workload Archive indicate that the proposed policy consistently outperforms traditional scheduling approaches.
Language, literature and the computer
Authors: Smillie Keith
Published: January 2007

A lecture given in the early 1980s on the importance of English language and literature to persons studying computing in schools and universities is rewritten in light of the advances in computer technology in the intervening years and the somewhat different vantage point of the author.
CHI '88 trip report
Authors: Nielsen Jakob
Published: January 2007

"Do you want to spend the rest of your life selling sugared water or do you want a chance to
change the world
?" By asking this question, the then chairman of Apple
Steve Jobs
enticed John Sculley away from his fast track career in Pepsi. Similar considerations form a large part of my own motivation for working in the user interface field. As
Ben Shneiderman
said in his keynote speech at CHI'86: Our work will influence how people live in the next century.
Color in screen display: a draft international standard
Authors: Smith Wanda
Published: January 2007

Until relatively recently, color in computer display images has been primarily applied to business graphics and solid models. In addition, color has not, until recently, been used to aid in critical decisions. Color is now being utilized as a visual aid to monitor scientific and industrial processes, visualize and code measurements (e.g., waveforms), evaluate medical conditions (e.g., tumors) and image mathematical expressions (e.g., fractals) which predict random events and natural formations.
Designing menu display format to match input device format
Authors: Perlman Gary , Sherwin Leo C.
Published: January 2007

We report the results of an experiment designed to measure the effects of modeling menu format to match the format of input devices. Subjects were presented with menus in layouts of varying compatibility with two common input devices: IBM PC function keys in a matrix format and the digit keys at the top of standard keyboards. The results showed that the better the match between formats of menus and devices, the lower the selection times. Guidelines for the design of displays suggest that the best way to show items is in a vertical sorted list, which is incompatible with the format of IBM function keys. We conclude that software designers should model menu display formats after the selection hardware.
Designing conceptual models of dialog: a case for dialog charts
Authors: Ariav Gad , Calloway Linda-Jo
Published: January 2007

The conceptual design of user interfaces focuses on the specification of the structure of the dialog, independent of any particular implementation approach. The intensifying discussion of conceptual dialog models is an inevitable result of the recent consolidation of a dialog management paradigm. This paradigm partitions a system/user dialog into three generic functions: the processing of syntax, the processing of control and the processing of the applications (Figure 1-1). This conceptualization essentially underlies a wide array of contemporary dialog models, expressed in various terminologies. The
control processor
maintains and enforces the
dialog structure
, practically defining the set of permissible dialogs, keeping track of the sequencing of user-system activities and maintaining the contextual information about the interaction.
The effectiveness of a keystroke line in interactive tutorials
Authors: Campbell Gwendolyn
Published: January 2007

Business software is becoming increasingly sophisticated and powerful. At the same time, these packages are being put into the hands of inexperienced computer users. A novice must acquire both a conceptual understanding of the program's potential, and the specific procedural knowledge necessary to utilize that potential. Without adequate training this can be a time consuming and frustrating, if not impossible, task.
Fine tuning selection semantics in a structure editor based programming environment: some experimental results
Authors: Goldenson Dennis R. , Lewis Marjorie B.
Published: January 2007

Structure editing holds much promise for improving the quality of introductory programming education. However early structure editors have often been clumsy and counter intuitive to use. This study reports the results of a laboratory experiment in which the user interface of a structure editing environment was modified in several ways to make its semantics more closely resemble what students seem naturally to expect. Analysis suggests that it is possible to improve students' editing performance, without getting bogged down in unnecessary details of language and environmental semantics.
Computer aids for vision and employment (CAVE)
Authors: Griffith Douglas , Doss Hodge , Winfree David
Published: January 2007

The percentage of blind and visually impaired (VI) adults of working age who are gainfully employed is approximately 33%. The confluence of two factors, the changing nature of the world of work and developments in microcomputer technology, offer the potential of greatly reducing the magnitude of this problem. In the information age a strong majority of jobs can be classified as information processing jobs. Given suitable adaptations, the blind and VI can perform such jobs using microcomputers.
User interface primitives to allow full functional use of computers by physically disabled persons
Authors: McDougall Jeff , Fels Deb , Milner Morris , MacMillan Hugh
Published: January 2007

As a result of some physical, sensory or cognitive deficit, a person may be unable to interpret standard computer output, i.e. a visual display. If computer applications were written such that the output could be re-directed and possibly translated into an appropriate modality (visual, auditory or tactile) and form of presentation, that user would not be handicapped by the technology. Techniques of device independent output, such as the Graphics Kernel System (GKS) provide some relief in terms of alternate visual displays. However, the output primitives they suggest are insufficient for auditory or tactile modalities.
Load balancing for clustered web farms
Authors: Wolf Joel L. , Yu Philip S.
Published: January 2007

We propose a scheme which attempts to optimally balance the load on the servers of a clustered web farm. Solving this performance problem is crucial to achieving minimal average response time for customer requests, and thus ultimately to achieving maximal customer throughput. This short paper gives an overview of three new mathematical contributions. First, we describe a
goal setting
algorithm to determine the load on each server which minimizes the average customer request response time given the possibly overlapping cluster assignments of sites to servers and the current customer request load for each site. The cluster assignments, which of necessity can only be changed relatively infrequently, have a major effect on the optimal response time in the goal setting component. So, second, we describe a
static
algorithm which determines good assignments of sites to servers. Third, and finally, we describe a
dynamic
algorithm which handles the real-time server load balancing, reacting to the fluctuating customer request load in order to come as close as possible to achieving the idealized optimal average response time. We examine the performance of the overall load balancing scheme via simulation experiments.
Transient analysis applied to traffic modeling
Authors: de Souza e Silva Edmundo , Leão Rosa M. M. , Diniz Morganna C.
Published: January 2007

Traffic modeling has been an extensive area of research in the last few years, and a lot of modeling effort has been devoted to better understand the issues involved in multiplexing traffic over high speed links. The goals of the performance analyst include the development of accurate traffic models to predict, with sufficient accuracy, the impact of the traffic generated by applications over the network resources, and the evaluation of the quality of service (QoS) being achieved. Performance studies include determining buffer behavior, evaluate cell loss probability, admission control algorithms, and many others.One performance study issue is the calculation of
descriptors
from different traffic models. In the literature, one can find a large number of models that have been proposed, including Markov and non-Markovian models [1]. Although not possessing the long-range dependence property, Markov models are still attractive not only due to their mathematical tractability but also because it has been shown that long-range correlations can be approximately obtained from certain kinds of Markovian models (e.g. [11]). Furthermore, works such as [8] show that Markov models can be used to accurately predict performance metrics.Once a set of traffic models is chosen, the modeler should obtain the desired performance measures. Hopefully the measures should be calculated analytically using efficient algorithms.The modeling steps briefly outlined above may require the transient analysis of general Markovian models, including Markov reward models. One of the goals of this work is to present new algorithms we developed to obtain efficiently measures such as the transient queue length distribution (and from that, the packet loss ratio as a function of time) directly from the model of the source feeding the queue. We also obtain second order descriptors such as the index of dispersion and the autocovariance from the source models. Using these algorithms the modeler can evaluate the efficacy of different Markovian models to predict performance metrics.
Large deviation analysis for multiplexing independent regulated inputs
Authors: Chang Cheng-Shang , Chiu Yuh-ming , Song Wheyming Tina
Published: January 2007

In this paper, we consider the performance analysis problem for a work conserving link with a large number of independent regulated inputs. For such a problem, we derive simple stochastic bounds under a general traffic constraint for the inputs. The bound for queue length is shown to be a stochastic extension of the deterministic worst case bound and it is asymptotically tighter than the bound in Kesidis and Konstantopoulos [5]. We also test the bound by considering periodic inputs with independent starting phases. Based on importance sampling, we propose a fast simulation algorithm that achieves significant variance reduction. The simulations results are compared with our stochastic bound and the bound [5].
Convex stability and asymptotic convex ordering for non-stationary arrival processes
Authors: Kuang Lei , Makowski Armand M.
Published: January 2007

The notion of convex stability for a sequence of non-negative random variables is discussed in the context of several applications.
Analysis of speculative prefetching
Authors: Angermann Michael
Published: January 2007

Prefetching is a potential method to reduce waiting time for retrieving data over wireless network connections that commonly occur in mobile scenarios. These connections typically exhibit low bandwidth as well as high latency. This article analyzes fundamental principles in speculative prefetching. Based on a simplified system model, the influence of parameters and strategies on prefetching performance is investigated, both analytically and in simulation. The reduction of the mean waiting time is used as performance metric. An example is given that makes use of the Zipf distribution to demonstrate the influence of the documents' probability distribution and its parameters. A low-complexity algorithm that performs optimally under the given assumptions is presented.
A system based on XML for supporting the management of educational web sites
Authors: Van Huu Le
Published: January 2007

Disseminating the course information is one of the main assignments of an academic teacher. This paper proposes a system for supporting the teacher in creating, updating, organizing and retrieving files that belong to his/her own Web site. The system is capable of organizing the attributes of the files contained in an educational Web server in an appropriate database and updating link addresses of Web pages when some data files are created. The system is based on the XML language and related technologies, such as DOM and XSL.
XML and the future of humanities computing
Authors: Niccolucci Franco
Published: January 2007

The existence of XML induces to hope that some limits of humanities computing may soon be trespassed. Here we mention some arguments concerning data management and 3D visualization, describing a few examples and test cases where the use of XML dramatically improved the quality of the application. These include text encoding, archaeological data management and Virtual Reality reconstruction of Cultural Heritage.
A Java-based framework to support computer-assisted creation of structured XML documents
Authors: Trentini Andrea
Published: January 2007

In the management of document-based information, the structure of the document itself is very important. In the XML world you can use a DTD (Document Type Definition) or XMLSchema to define that structure. But not everything can be described (and forced) through a DTD while XMLSchema is not yet widely supported. For our MENTOR project - a document-based university management system - we needed a tool to support the creation and storage of official-meeting transcripts. These documents are strongly structured, so strongly that in this case a simple DTD was not enough. We decided to build a custom tool to fulfill our need. In this article we show the different solutions we had to study to let users create XML documents with some considerations about the formalization level of each solution. Then we present and motivate our choice.
The influence of environmental uncertainty on the strategic use of information systems
Authors: Kearns Grover S. , Lederer Albert L.
Published: January 2007

How market hostility affects managerial competencies is an important human resources issue. The role of the CEO in strategic information systems planning and the CIO business planning may become more important under environmental uncertainty, especially for firms highly dependent upon information technology. In this study, CIOs were surveyed determine how environmental uncertainty information intensity impacted the role strategic IS planning practices. Both environmental uncertainty and information intensity were more strongly related to SISP practices in the electric utility industry when compared to other industries surveyed. Undergoing deregulation, electric utility companies are now being exposed to a level of environmental hostility not experienced in the past. Results indicate that a sudden change in environmental uncertainty may be a more important motivation to the use of SISP practices than the level of uncertainty itself. Data also suggest that information intensity may moderate the relationship between environmental uncertainty and SISP practices.
SPARTAN
Authors: Babu Shivnath , Garofalakis Minos , Rastogi Rajeev
Published: January 2007

While a variety of lossy compression schemes have been developed for certain forms of digital data (e.g., images, audio, video), the area of lossy compression techniques for arbitrary data tables has been left relatively unexplored. Nevertheless, such techniques are clearly motivated by the ever-increasing data collection rates of modern enterprises and the need for effective, guaranteed-quality approximate answers to queries over massive relational data sets.In this paper, we propose
SPARTAN,
a system that takes advantage of attribute semantics and data-mining models to perform lossy compression of massive data tables.
SPARTAN
is based on the novel idea of exploiting predictive data correlations and prescribed error-tolerance constraints for individual attributes to construct concise and accurate
Classification and Regression Tree (CaRT)
models for entire columns of a table. More precisely,
SPARTAN
selects a certain subset of attributes (referred to as
predicted
attributes) for which no values are explicitly stored in the compressed table; instead, concise
error-constrained
CaRTs that predict these values (within the prescribed error tolerances) are maintained. To restrict the huge search space of possible CaRT predictors,
SPARTAN
uses a Bayesian network structure to guide the selection of CaRT models that minimize the overall storage requirement, based on the prediction and materialization costs for each attribute.
SPARTAN
's CaRT-building algorithms employ novel integrated pruning strategies that take advantage of the given error constraints on individual attributes to minimize the computational effort involved. Our experimentation with several real-life data sets offers convincing evidence of the effectiveness of
SPARTAN
's model-based approach ---
SPARTAN
is able to consistently yield substantially better compression ratios than existing semantic or syntactic compression tools (e.g., gzip) while utilizing only small samples of the data for model inference.