ppxscal/embedding_network huggingface dataset:
Performance engineering in data Grids: Research Articles
Authors: Erwin Laure, Heinz Stockinger, Kurt Stockinger
Venue: Concurrency and Computation: Practice Experience (2005)

The vision of Grid computing is to facilitate worldwide resource sharing among distributed collaborations. With the help of numerous national and international Grid projects, this vision is becoming reality and Grid systems are attracting an ever increasing user base. However, Grids are still quite complex software systems whose efficient use is a difficult and error-prone task. In this paper we present performance engineering techniques that aim to facilitate an efficient use of Grid systems, in particular systems that deal with the management of large-scale data sets in the tera- and petabyte range (also referred to as data Grids). These techniques are applicable at different layers of a Grid architecture and we discuss the tools required at each of these layers to implement them. Having discussed important performance engineering techniques, we investigate how major Grid projects deal with performance issues particularly related to data Grids and how they implement the techniques presented. Copyright &copy; 2005 John Wiley & Sons, Ltd.
Book review: LOGIC PROGRAMMING AND ITS APPLICATIONS. edited by Michel van Caneghem and David H. D. Warren. Ablex Series in Artificial Intelligence (Ablex Publishing Corporation, 1986)
Venue: Issue 98 (October 1986) (1986)

The book brings together eighteen refereed papers grouped into six areas:* languages and formalisms* implementation* tools* applications* natural language* future directions The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Understanding the Performance of Cooperative Web Caching Systems
Authors: Xiaosong Hu, A. Nur Zincir-Heywood
Venue: Proceedings of the 3rd Annual Communication Networks and Services Research Conference (2005)

Web caching has been recognized as an effective scheme to alleviate the service bottleneck and reduce the network traffic, thereby minimizing the user access latency on the Internet. To maximize the performance of caching, cache cooperation systems such as Hierarchical, Distributed and Hybrid are employed. In this work, we first derive an analytical model to calculate the performance parameters for the aforementioned three caching systems. We then test these systems on a web cache simulator. Results show that the hybrid system is very competitive in terms of the hit ratio and the bandwidth usage compared to the distributed system and hierarchical system, respectively. On the other hand, the hybrid system gives the optimal results in terms of latency and the number of hops.
Garside monoids vs divisibility monoids
Authors: Matthieu Picantin
Venue: Mathematical Structures in Computer Science (2005)

Divisibility monoids are a natural algebraic generalisation of Mazurkiewicz trace monoids, namely monoids in which the distributivity of the underlying lattices is kept as a hypothesis, but the relations between the generators are not necessarily supposed to be commutations. Garside monoids are a natural algebraic generalisation of spherical Artin monoids, namely monoids in which the existence of common multiples is kept as a hypothesis, but the relations between the generators are not necessarily supposed to be of Coxeter type. Here, we show that the quasi-centre of these monoids can be studied and described in a similar way, and then we exhibit the intersection between the two classes of monoids.
Automatic IEEE 802.11 rate control for streaming applications: Research Articles
Authors: Ivaylo Haratcherev, Jacco Taal, Koen Langendoen, Reginald Lagendijk, Henk Sips
Venue: Wireless Communications Mobile Computing (2005)

Streaming multimedia content in real-time over a wireless link is a challenging task because of the rapid fluctuations in link conditions that can occur due to movement, interference, and so on. The popular IEEE 802.11 standard includes low-level tuning parameters like the transmission rate. Standard device drivers for today's wireless products are based on gathering statistics and consequently, adapt rather slowly to changes in conditions. To meet the strict latency requirements of streaming applications, we designed and implemented an advanced hybrid control algorithm that uses signal-strength (SNR) information to achieve fast responses. Since SNR readings are quite noisy, we do not use that information to directly control the rate setting, but rather as a safeguard limiting the range of feasible settings to choose from. We report on real-time experiments involving two laptops equipped with IEEE 802.11a wireless interface cards. The results show that using SNR information greatly enhances responsiveness in comparison to statistics-based rate controllers. Finally, we will present the results of an experiment with real-time video streaming to a moving laptop in an office-like environment. Our hybrid control algorithm effectively prevented many packet losses, thereby achieving a much higher video quality than the statistics-based algorithm. Copyright &copy; 2005 John Wiley & Sons, Ltd.
Review of "Discrete Neural Networks: A Theoretical Foundation by Kai-Yeung Siu, Vwani Roychowdhury and Thomas Kailath", Prentice Hall PTR, 1995, ISBN 0-13-300708-1.
Authors: Vir V. Phoha
Venue: ACM SIGART Bulletin (1998)

This book is an important addition to the neural networks literature and fills a void by presenting, in one volume, the important computational issues in discrete neural networks. The book deals with the computational complexity of problems being solved by systems of parallel processing elements.
A greedy strategy for detecting negative cost cycles in networks
Authors: K. Subramani, L. Kovalchick
Venue: Future Generation Computer Systems (2005)

In this paper, we develop a greedy strategy for the problem of checking whether a network (directed graph) with positive and negative costs on its edges has a negative cost cycle. We call our approach the Vertex Contraction algorithm; it is the first known greedy strategy for this problem. As per the literature, all known approaches to the problem of detecting negative cost cycles are based on dynamic programming or scaling. It is well known that the negative cost cycle detection problem is equivalent to the problem of checking whether a system of linear difference constraints is feasible. Our algorithm exploits this equivalence and uses polyhedral projection on the polyhedron of linear difference constraints, corresponding to the input network, to detect the presence of negative cost cycles. We use a variant of the Fourier-Motzkin elimination procedure to effect polyhedral projection and contrast the performance of our algorithm with the "standard" Bellman-Ford algorithm for the same problem. We observed that the Vertex Contraction algorithm performed an order of magnitude better than the Bellman-Ford algorithm on a range of randomly generated inputs, thereby conclusively demonstrating the superiority of our approach. From the perspective of asymptotic analysis, the Bellman-Ford algorithm is superior to our algorithm, in that it runs in time O(mċn) in the worst case, on a network with m edges and n vertices, whereas the worst-case complexity of our algorithm is O(n3).
On the block-structured distance to non-surjectivity of sublinear mappings
Authors: Javier Pe&#x00f1;a
Venue: Mathematical Programming: Series A and B (2005)

We show that the block-structured distance to non-surjectivity of a set-valued sublinear mapping equals the reciprocal of a suitable block-structured norm of its inverse. This gives a natural generalization of the classical Eckart and Young identity for square invertible matrices.
Upgrading and Repairing Microsoft Windows
Authors: Scott Mueller
Venue:  (2005)

Fans of Upgrading and Repairing PCs, your call has been answered. Scott Mueller, author of the best-selling Upgrading and Repairing PCs, is now bringing you an equally in-depth guide to Windows troubleshooting. Upgrading and Repairing Microsoft Windows explains how Windows works and how to fix it when things go wrong. This comprehensive resource includes information on: Installation Managing security Optimizing performance Recovering data Configuring settings and the registry Protecting Windows from viruses and spywareScott also includes references to helpful tools and scripting commands for maximum system controls. A DVD is included that provides you with additional resources and unique how-to video that brings Scott right to you. Find out how to make Windows work with you and not against you with Upgrading and Repairing Microsoft Windows.
An investigation of software engineering curricula
Authors: Barbara Kitchenham, David Budgen, Pearl Brereton, Philip Woodall
Venue: Journal of Systems and Software (2005)

We adapted a survey instrument developed by Timothy Lethbridge to assess the extent to which the education delivered by four UK universities matches the requirements of the software industry. We propose a survey methodology that we believe addresses the research question more appropriately than the one used by Lethbridge. In particular, we suggest that restricting the scope of the survey to address the question of whether the curricula for a specific university addressed the needs of its own students, allowed us to identify an appropriate target population. However, our own survey suffered from several problems. In particular the questions used in the survey are not ideal, and the response rate was poor.Although the poor response rate reduces the value of our results, our survey appears to confirm several of Lethbridge's observations with respect to the over-emphasis of mathematical topics and the under-emphasis on business topics. We also have a close agreement with respect to the relative importance of different software engineering topics. However the set of topics, that we found were taught far less than their importance would suggest, were quite different from the topics identified by Lethbridge.
Tool for accurately predicting website navigation problems, non-problems, problem severity, and effectiveness of repairs
Authors: Marilyn Hughes Blackmon, Muneo Kitajima, Peter G. Polson
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2005)

The Cognitive Walkthrough for the Web (CWW) is a partially automated usability evaluation method for identifying and repairing website navigation problems. Building on five earlier experiments [3,4], we first conducted two new experiments to create a sufficiently large dataset for multiple regression analysis. Then we devised automatable problem-identification rules and used multiple regression analysis on that large dataset to develop a new CWW formula for accurately predicting problem severity. We then conducted a third experiment to test the prediction formula and refined CWW against an independent dataset, resulting in full cross-validation of the formula. We conclude that CWW has high psychological validity, because CWW gives us (a) accurate measures of problem severity, (b) high success rates for repairs of identified problems (c) high hit rates and low false alarms for identifying problems, and (d) high rates of correct rejections and low rates of misses for identifying non-problems.
Subtraction-free almost montgomery inverse algorithm
Authors: Róbert Lórencz, Josef Hlaváč
Venue: Information Processing Letters (2005)

A new modification of Kaliski's algorithm for computing the Almost Montgomery Inverse, optimized for implementation in hardware, is presented. The algorithm and the corresponding portion of the hardware architecture overcome certain drawbacks of the currently used methods. In particular, the "less than/greater than" tests that represent subtractions are avoided.
Evaluating event visualization: a usability study of COPLINK spatio-temporal visualizer
Authors: Wingyan Chung, Hsinchun Chen, Luis G. Chaboya, Christopher D. O'Toole, Homa Atabakhsh
Venue: International Journal of Human-Computer Studies (2005)

Event visualization holds the promise of alleviating information overload in human analysis and numerous tools and techniques have been developed and evaluated. However, previous work does not specifically address either the coordination of event dimensions with the types of tasks involved or the way that visualizing different event dimensions can benefit human analysis. In this paper, we propose a taxonomy of event visualization and present a methodology for evaluating a coordinated event visualization tool called COPLINK Spatio-Temporal Visualizer (STV). The taxonomy encompasses various event dimensions, application domains, visualization metaphors, evaluation methods and performance measures. The evaluation methodology examines different event dimensions and different task types, thus juxtaposing two important elements of evaluating a tool. To achieve both internal and external validity, a laboratory experiment with students and a field study with crime analysis experts were conducted. Findings of our usability study show that STV could support crime analysis involving multiple, coordinated event dimensions as effectively as it could analyze individual, uncoordinated event dimensions. STV was significantly more effective and efficient than Microsoft Excel in performing coordinated tasks and was significantly more efficient in doing uncoordinated tasks related to temporal, spatial and aggregated information. Also, STV had compared favorably with Excel in completing uncoordinated tasks related to temporal and spatial information, respectively. Subjects' comments showed STV to be intuitive, useful and preferable to existing crime analysis methods.
Defining and Measuring the Productivity of Programming Languages
Authors: Ken Kennedy, Charles Koelbel, Robert Schreiber
Venue: International Journal of High Performance Computing Applications (2004)

The goal of programming support systems is to make it possible for application developers to produce software faster, without any degradation in software quality. However, it is essential that this goal must not be achieved at the cost of performance: programs written in a high-level language and intended to solve large problems on highly parallel machines must not be egregiously less efficient than the same applications written in a lower-level language. Because this has been a traditional stumbling block for high-level languages, metrics for productivity analysis must explore the trade-off between programming effort and performance.To that end, we propose the use of two dimensionless ratios, relative power and relative efficiency, to measure the productivity of programming interfaces. In this paper we define these concepts, describe their application, and explore various ways for measuring them, including both empirical strategies and expert opinion. Rather than combine these metrics into a single number representing a universal productivity, we propose that they be represented graphically in at least two dimensions so that the trade-offs between abstraction and performance are clearly depicted. However, we also introduce a single problem-dependent parameter that allows us to reason about the relative productivity of two languages for a given problem.
Test Data Likelihood for PLSA Models
Authors: Thorsten Brants
Venue: Information Retrieval (2005)

Probabilistic Latent Semantic Analysis (PLSA) is a statistical latent class model that has recently received considerable attention. In its usual formulation it cannot assign likelihoods to unseen documents. Furthermore, it assigns a probability of zero to unseen documents during training. We point out that one of the two existing alternative formulations of the Expectation-Maximization algorithms for PLSA does not require this assumption. However, even that formulation does not allow calculation ofthe actual likelihood values. We therefore derive a new test-data likelihood substitute for PLSA and compare it to three existing likelihood substitutes. An empirical evaluation shows that our new likelihood substitute produces the best predictions about accuracies in two different IR tasks and is therefore best suited to determine the number of EM steps when training PLSA models. The new likelihood measure and its evaluation also suggest that PLSA is not very sensitive to overfitting for the two tasks considered. This renders additions like tempered EM that especially address overfitting unnecessary.
Asynchronous iterations with flexible communication: contracting operators
Authors: Didier El Baz, Andreas Frommer, Pierre Spiteri
Venue: Journal of Computational and Applied Mathematics (2005)

The concept of flexible communication permits one to model efficient asynchronous iterations on parallel computers. This concept is particularly useful in two practical situations. Firstly, when communications are requested while a processor has completed the current update only partly, and secondly, in the context of inner/outer iterations, when processors are also allowed to make use of intermediate results obtained during the inner iteration in other processors.In the general case of nonlinear or linear fixed point problems, we give a global convergence results for asynchronous iterations with flexible communication whereby the iteration operators satisfy certain contraction hypotheses. In this manner we extend to a contraction context previous results obtained for monotone operators with respect to a partial ordering.
Reasoning about evolving nonmonotonic knowledge bases
Authors: Thomas Eiter, Michael Fink, Giuliana Sabbatini, Hans Tompits
Venue: ACM Transactions on Computational Logic (TOCL) (2005)

Recently, several approaches to updating knowledge bases modeled as extended logic programs have been introduced, ranging from basic methods to incorporate (sequences of) sets of rules into a logic program, to more elaborate methods which use an update policy for specifying how updates must be incorporated. In this article, we introduce a framework for reasoning about evolving knowledge bases, which are represented as extended logic programs and maintained by an update policy. We first describe a formal model which captures various update approaches, and we define a logical language for expressing properties of evolving knowledge bases. We then investigate semantical and computational properties of our framework, where we focus on properties of knowledge states with respect to the canonical reasoning task of whether a given formula holds in a given evolving knowledge base. In particular, we present finitary characterizations of the evolution for certain classes of framework instances, which can be exploited for obtaining decidability results. In more detail, we characterize the complexity of reasoning for some meaningful classes of evolving knowledge bases, ranging from polynomial to double exponential space complexity.
Efficient Multimatch Packet Classification and Lookup with TCAM
Authors: Fang Yu, Randy H. Katz, T. V. Lakshman
Venue: IEEE Micro (2005)

Ternary content-addressable memory is becoming a common extension to network processors, and its capability and speed make it attractive for high-speed networks. The authors' TCAM-based scheme produces multimatch classification results with about 10 times fewer memory lookups than a pure software approach. In addition, their scheme for removing negation in rule sets saves up to 95 percent of the TCAM space used by a straightforward implementation.
A web-based consumer-oriented intelligent decision support system for personalized e-services
Authors: Chien-Chih Yu
Venue: Proceedings of the 6th international conference on Electronic commerce (2004)

Due to the rapid advancement of electronic commerce and web technologies in recent years, the concepts and applications of decision support systems have been significantly extended. One quickly emerging research topic is the consumer-oriented decision support system that provides functional supports to consumers for efficiently and effectively making personalized decisions. In this paper we present an integrated framework for developing web-based consumer-oriented intelligent decision support systems to facilitate all phases of consumer decision-making process in business-to-consumer e-services applications. Major application functional modules comprised in the system framework include consumer and personalized management, navigation and search, evaluation and selection, planning and design, community and collaboration management, auction and negotiation, transactions and payments, quality and feedback control, as well as communications and information distributions. System design and implementation methods will be illustrated using an example. Also explored are various potential e-services application domains including e-tourism and e-investment.
A framework for data mining pattern management
Authors: Barbara Catania, Anna Maddalena, Maurizio Mazza, Elisa Bertino, Stefano Rizzi
Venue: Proceedings of the 8th European Conference on Principles and Practice of Knowledge Discovery in Databases (2004)

To represent and manage data mining patterns, several aspects have to be taken into account: (i) patterns are heterogeneous in nature; (ii) patterns can be extracted from raw data by using data mining tools (a-posteriori patterns) but also defined by the users and used for example to check how well they represent some input data source (a-priori patterns); (iii) since source data change frequently, issues concerning pattern validity and synchronization are very important; (iv) patterns have to be manipulated and queried according to specific languages. Several approaches have been proposed so far to deal with patterns, however all of them lack some of the previous characteristics. The aim of this paper is to present an overall framework to cope with all these features.
Wizard of Oz interfaces for mixed reality applications
Authors: Steven Dow, Jaemin Lee, Christopher Oezbek, Blair MacIntyre, Jay David Bolter, Maribeth Gandy
Venue: CHI '05 extended abstracts on Human factors in computing systems (2005)

One important tool for developing complex interactive applications is "Wizard of Oz "(WOz)simulation.WOz simulation allows design concepts,content and partially completed applications to be tested on users without the need to first create a completely working system.In this paper we discuss the integration of wizard interface tools into a Mixed Reality (MR)design environment and show how easier creation and evolution of wizard interfaces can lead to an expanded role for WOz-based testing during the design evolution of MR experiences.We share our experiences designing an audio experience in an historic site,and illustrate the evolution of the wizard interfaces alongside the user experience