ppxscal/embedding_network huggingface dataset:
k Workers in a Circular Warehouse: A Random Walk on a Circle, without Passing
Authors: Joseph D. Skufca
Venue: SIAM Review (2005)

We consider the problem of stochastic flow of multiple particles traveling on a closed loop, with a constraint that particles move without passing. We use a Markov chain description that reduces the problem to a generalized random walk on a hyperplane (with boundaries). By expressing positions via a moving reference frame, the geometry of the no-passing criteria is greatly simplified, with the resultant condition expressible as the coordinate system planes which bound the first orthant. To determine state transition probabilities, we decompose transitions into independent events and construct a digraph representation in which calculating transition probability is reduced to a shortest path determination on the digraph. The resultant decomposition digraph is self-converse, and we exploit that property to establish the necessary symmetries to find the stationary density for the process.
A Load Balancing Method for a Parallel Application Based on a Domain Decomposition
Authors: Christophe Denis, Jean-Paul Boufflet, Piotr Breitkopf
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

The parallel multiple front method is used in mechanical engineering to solve large sparse linear systems issued from finite element modeling. It is a parallel direct method based on a nonoverlapping domain decomposition method. The decomposition is usually built with a graph partitioning approach. However this approach is not well suited to all parallel applications. It provides computing times over the subdomains which can vary from simple to double for our parallel multiple method. We show that its computing time can be decreased by load balancing the computational volume over the subdomains. We present in this communication a sequential and a parallel version of our load balancing method which corrects in computational volume an initial decomposition issued from graph partitioning tools.
A linear time algorithm for the minimum weighted feedback vertex set on diamonds
Authors: F. Carrabs, R. Cerulli, M. Gentili, G. Parlato
Venue: Information Processing Letters (2005)

Given an undirected and vertex weighted graph G, the Weighted Feedback Vertex Problem (WFVP) consists in finding a subset F ⊆ V of vertices of minimum weight such that each cycle in G contains at least one vertex in F. The WFVP on general graphs is known to be NP-hard. In this paper we introduce a new class of graphs, namely the diamond graphs, and give a linear time algorithm to solve WFVP on it.
The generalized minimum spanning tree problem: Polyhedral analysis and branch-and-cut algorithm
Venue: Networks (2004)

This article presents a branch-and-cut algorithm for the Generalized Minimum Spanning Tree Problem &lpar;GMSTP&rpar;. Given an undirected graph whose vertex set is partitioned into clusters, the GMSTP consists of determining a minimum-cost tree including exactly one vertex per cluster. Applications of the GMSTP are encountered in telecommunications. An integer linear programming formulation is presented and new classes of valid inequalities are developed, several of which are proved to be facet-defining. A branch-and-cut algorithm and a tabu search heuristic are developed. Extensive computational experiments show that instances involving up to 160 or 200 vertices can be solved to optimality, depending on whether edge costs are Euclidean or random. &copy; 2004 Wiley Periodicals, Inc.
Shape-From-Silhouette Across Time Part II: Applications to Human Modeling and Markerless Motion Tracking
Authors: Kong-Man (German) Cheung, Simon Baker, Takeo Kanade
Venue: International Journal of Computer Vision (2005)

In Part I of this paper we developed the theory and algorithms for performing Shape-From-Silhouette (SFS) across time. In this second part, we show how our temporal SFS algorithms can be used in the applications of human modeling and markerless motion tracking. First we build a system to acquire human kinematic models consisting of precise shape (constructed using the temporal SFS algorithm for rigid objects), joint locations, and body part segmentation (estimated using the temporal SFS algorithm for articulated objects). Once the kinematic models have been built, we show how they can be used to track the motion of the person in new video sequences. This marker-less tracking algorithm is based on the Visual Hull alignment algorithm used in both temporal SFS algorithms and utilizes both geometric (silhouette) and photometric (color) information.
Local Language Support for Handheld Devices
Authors: Yaswanth Narvaneni, M. B. Srinivas
Venue: Proceedings of the International Conference on Information Technology: Coding and Computing (ITCC'05) - Volume II - Volume 02 (2005)

Handheld devices or Personal Digital Assistants (PDAs) are increasingly being used for purposes other than storing personal information. A wide variety of applications is being developed to take advantage of computing power available on PDAs. Also a need is being felt in non-English speaking countries like India to develop applications in local languages. Such applications are expected to be useful in field like education, health and census etc., for data collection and dissemination. It is the purpose of this paper to show how support for local language can be built on low cost PDAs.
QQ: Nanoscale Timing and Profiling
Authors: James Frye, James G. King, Christine J. Wilson, Frederick C. Harris,  Jr.
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 15 - Volume 16 (2005)

QQ is a tool for timing and memory profiling capable of nanoscale time resolution. Designed to minimize both learning curve and impact on the profiled code, it is platform independent and usable with sequential, distributed, and parallel programs. QQ is invoked via embedded function calls, and outputs event and timing records in a compact binary format. These records can be analyzed by external software packages. QQ obtains timing information from the hardware performance monitoring facilities designed into current microprocessors. Our implementation addresses the IA32 architecture, but the similar facilities of most modern processors allow QQ to readily be ported to other platforms.
The Study and Implementation of the Multigrid Algorithm for the 3-D Transport Difference Equation
Authors: Yang Shulin, Shen Weidong
Venue: Proceedings of the 19th International Symposium on High Performance Computing Systems and Applications (2005)

In order to accelerate the iterative convergence, the multigrid algorithm for the 3D time-dependent neutron transport difference equation is studied in this paper. The detail description for this algorithm and the processes of the implementation are given, and the comparison and conclusionfor the numerical results are listed.
A theoretical concept for XML-enabled global small business networks
Authors: Nils Schumacher
Venue: Proceedings of the 2004 international symposium on Information and communication technologies (2004)

The exchange of business data between business partners using EDI was used in the past by consolidated companies or in a supply chain relationship. Data was only exchanged by using Value Added Networks (VANs) or industry specific subsets. Small business companies would only join this kind of EDI if they were forced to. A typical reason to use EDI was the role of the company as a supplier in the automated supply chain of a large consolidated company being the only or main customer. The slogan was "EDI or die". The reason for distrust regarding the EDI technology and its weak acceptance were the high costs of the VANs and, as result, the risk of dependency on the major customer as well as scepticism with regard to information technology in general [16].The use of the Internet, mainly the World Wide Web (WWW), enables a more cost efficient access to business networks. The price decline of hardware and the presence of Open Source Software make it more attractive to use information technology. In addition, because of the dispersion of the increase in the use of information technology, small business companies have easier access to qualified human resources. Usage of the internet to submit EDI data via the established protocols or new ways like EDI via XML or Web-EDI and between different applications and ERP-Systems is a great advance and it enables global E-business networks [1].Our paper describes how this evolution enables small and midsize businesses to share the globalized markets of today by joining global strategic networks. It will present a concept of how to enable these companies to find their preferred strategic business partners and what strategic impact the use of this technology will have. It also presents an outline of what the architecture of these networks may look like and how XML technology in particular can be a primary technology in this context.
An integrative approach to high-performance biomedical problem solving environments on the Grid
Authors: Alfredo Tirado-Ramos, Peter M. A. Sloot, Alfons G. Hoekstra, Marian Bubak
Venue: Parallel Computing (2004)

We conduct computer simulation experiments in pre-operative planning of vascular reconstruction with a physician in the experimental loop. We constructed a problem solving environment, which offers an integrative approach for constructing and running complex interactive systems. Grid resources are used for access to medical image repositories, segmentation services, simulation of blood flow, and visualization in virtual environments of the simulated results together with medical data obtained from MRI/CT scanners. This case study in vascular reconstruction planning has been validated via contextual analysis in a number of hospitals, resulting in a set of new requirements gathered for future versions of the system.
Information systems research methodologies and models
Authors: Albertas Caplinskas, Olegas Vasilecas
Venue: Proceedings of the 5th international conference on Computer systems and technologies (2004)

The paper argues that one of shortcomings of majority of the current doctoral study programs in information systems is insufficient attention to research methodology. Information systems is an emerging scientific discipline and, consequently, it is still not obvious what amount of knowledge on research issues should be included in the doctoral study program. The paper discusses the body of knowledge in this field recommended for doctoral students in information systems. It is based on two years experience in teaching the module "Research principles and methods" for doctoral students in information systems field.
Digging into acceptor splice site prediction: an iterative feature selection approach
Authors: Yvan Saeys, Sven Degroeve, Yves Van de Peer
Venue: Proceedings of the 8th European Conference on Principles and Practice of Knowledge Discovery in Databases (2004)

Feature selection techniques are often used to reduce data dimensionality, increase classification performance, and gain insight into the processes that generated the data. In this paper, we describe an iterative procedure of feature selection and feature construction steps, improving the classification of acceptor splice sites, an important subtask of gene prediction. We show that acceptor prediction can benefit from feature selection, and describe how feature selection techniques can be used to gain new insights in the classification of acceptor sites. This is illustrated by the identification of a new, biologically motivated feature: the AG-scanning feature.The results described in this paper contribute both to the domain of gene prediction, and to research in feature selection techniques, describing a new wrapper based feature weighting method that aids in knowledge discovery when dealing with complex datasets.
A recursive random search algorithm for network parameter optimization
Authors: Tao Ye, Shivkumar Kalyanaraman
Venue: ACM SIGMETRICS Performance Evaluation Review (2004)

This paper proposes a new heuristic search algorithm, Recursive Random Search(RRS), for black-box optimization problems. Specifically, this algorithm is designed for the dynamical parameter optimization of network protocols which emphasizes on obtaining good solutions within a limited time frame rather than full optimization. The RRS algorithm is based on the initial high-efficiency property of random sampling and attempts to maintain this high-efficiency by constantly "restarting" random sampling with adjusted sample spaces. Due to its basis on random sampling, the RRS algorithm is robust to the effect of random noises in the objective function and it performs especially efficiently when handling the objective functions with negligible parameters. These properties have been demonstrated with the tests on a suite of benchmark functions. The RRS algorithm has been successfully applied to the optimal configuration of several network protocols. One application to a network routing algorithm is presented.
Robustness of real and virtual queue-based active queue management schemes
Authors: Ashvin Lakshmikantha, Carolyn L. Beck, R. Srikant
Venue: IEEE/ACM Transactions on Networking (TON) (2005)

In this paper, we evaluate the performance of both real and virtual queue-based marking schemes designed for use at routers in the Internet. Using fluid flow models, we show via analysis and simulations that Virtual Queue (VQ)-based marking schemes outperform Real Queue (RQ)-based marking schemes in terms of robustness to disturbances and the ability to maintain low queueing delays. In fact, we prove that a linearized model of RQ-based marking schemes exhibit a lack of robustness to constant but otherwise unknown levels of disturbances. The analytical results we present are applicable to combinations of proportionally fair and TCP-type congestion controllers at the source, and Random Exponential Marking (REM) and Proportional Control (PC) schemes at the router. The behavior of Random Early Discard (RED) and Proportional-Integral (PI) control schemes at the router are also studied via simulations.
Lexical chains for question answering
Authors: Dan Moldovan, Adrian Novischi
Venue: Proceedings of the 19th international conference on Computational linguistics - Volume 1 (2002)

The paper presents a method for finding topically related words on an extended WordNet. By exploiting the information in the WordNet glosses, the connectivity between the synsets is dramatically increased. Topical relations expressed as lexical chains on extended WordNet improve the performance of a question answering system by increasing the document retrieval recall and by providing the much needed axioms that link question keywords with answers.
On Using Exponential-Golomb Codes and Subexponential Codes for System-on-a-Chip Test Data Compression
Authors: Lei Li, Krishnendu Chakrabarty
Venue: Journal of Electronic Testing: Theory and Applications (2004)

We examine the use of exponential-Golomb codes and subexponential codes can be used for the compression of scan test data in core-based system-on-a-chip (SOC) designs. These codes are well-known in the data compression domain but their application to SOC testing has not been explored before. We show that these codes often provide slighly higher compression than alternative methods that have been proposed recently.
Lexical and semantic clustering by web links
Authors: Filippo Menczer
Venue: Journal of the American Society for Information Science and Technology (2004)

Recent Web-searching and -mining tools are combining text and link analysis to improve ranking and crawling algorithms. The central assumption behind such approaches is that there is a correlation between the graph structure of the Web and the text and meaning of pages. Here I formalize and empirically evaluate two general conjectures drawing connections from link information to lexical and semantic Web content. The link-content conjecture states that a page is similar to the pages that link to it, and the link-cluster conjecture that pages about the same topic are clustered together. These conjectures are often simply assumed to hold, and Web search tools are built on such assumptions. The present quantitative confirmation sheds light on the connection between the success of the latest Web-mining techniques and the small world topology of the Web, with encouraging implications for the design of better crawling algorithms.
Segmentation of Laparoscopic Images: Integrating Graph-Based Segmentation and Multistage Region Merging
Authors: Yueyun Shu, Guillaume-Alexandre Bilodeau, Farida Cheriet
Venue: Proceedings of the 2nd Canadian conference on Computer and Robot Vision (2005)

This paper presents a method that combines graph-based segmentation and multistage region merging to segment laparoscopic images. Starting with image pre-processing, including Gaussian smoothing, brightness and contrast enhancement, and histogram thresholding, we then apply an efficient graph-based method to produce a coarse segmentation of laparoscopic images. Next, regions are further merged in a multistage process based on features like grey-level similarity, region size and common edge length. At each stage, regions are merged iteratively according to a merging score until convergence. Experimental results show that our approach can achieve good spatial coherence, accurate edge location and appropriately segmented regions in real surgical images.
IP Lookup on a Platform FPGA: A Comparative Study
Authors: Dennis Bemmann
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 3 - Volume 04 (2005)

The efficient use of present resources is an important challenge in the design of embedded systems based on a platform FPGA. This paper discusses algorithms for IP lookup focusing on comparability and tradeoffs, rather than maximum performance. A hashing-based algorithm and a tree-based algorithm as examples for the two most common classes of IP lookup approches are investigated with regard to their implementation in programmable logic, their resource use and their performance, measured in lookup time. Through simulations it is determined how performance varies with changed resource availabity. A comparison also takes into account processor-based approaches and discusses use cases for the different implementations.
Computational theories on the function of theta oscillations
Authors: M&#x00e1;t&#x00e9; Lengyel, Zs&#x00f3;fia Huhn, P&#x00e9;ter &#x00c9;rdi
Venue: Biological Cybernetics (2005)

Neural rhythms can be studied in terms of conditions for their generation, or in terms of their functional significance. The theta oscillation is a particularly prominent rhythm, reported to be present in many brain areas, and related to many important cognitive processes. The generating mechanisms of theta have extensively been studied and reviewed elsewhere; here we discuss ideas that have accumulated over the past decades on the computational roles it may subserve. Theories propose different aspects of theta oscillations as being relevant for their cognitive functions: limit cycle oscillations in neuronal firing rates, subthreshold membrane potential oscillations, periodic modulation of synaptic transmission and plasticity, and phase precession of hippocampal place cells. The relevant experimental data is briefly summarized in the light of these theories. Specific models proposing a function for theta in pattern recognition, memory, sequence learning and navigation are reviewed critically. Difficulties with testing and comparing alternative models are discussed, along with potentially important future research directions in the field.
Predictive Performance Modelling of Parallel Component Composition
Authors: Lei Zhao, Stephen A. Jarvis, Daniel P. Spooner, Graham R. Nudd
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 15 - Volume 16 (2005)

Large-scale scientific computing applications frequently make use of closely-coupled distributed parallel components. The performance of such scientific applications is therefore dependent on the component parts and their interaction at run-time. This paper describes a methodology for predictive performance modelling of parallel applications composed of multiple interacting components. In this paper, the fundamental steps and required operations involved in the modelling process are identified - including inter-component dataflow analysis, MxN communication performance evaluation and composite performance model evaluation. A case study is presented to illustrate the modelling process and the methodology is verified through experimental analysis.
Mixing virtual and real scenes in the site of ancient Pompeii: Research Articles
Authors: George Papagiannakis, Sébastien Schertenleib, Brian O'Kennedy, Marlene Arevalo-Poizat, Nadia Magnenat-Thalmann, Andrew Stoddart, Daniel Thalmann
Venue: Computer Animation and Virtual Worlds (2005)

This paper presents an innovative 3D reconstruction of ancient fresco paintings through the real-time revival of their fauna and flora, featuring groups of virtual animated characters with artificial-life dramaturgical behaviours in an immersive, fully mobile augmented reality (AR) environment. The main goal is to push the limits of current AR and virtual storytelling technologies and to explore the processes of mixed narrative design of fictional spaces (e.g. fresco paintings) where visitors can experience a high degree of realistic immersion. Based on a captured&#x002F;real-time video sequence of the real scene in a video-see-through HMD set-up, these scenes are enhanced by the seamless accurate real-time registration and 3D rendering of realistic complete simulations of virtual flora and fauna (virtual humans and plants) in a real-time storytelling scenario-based environment. Thus the visitor of the ancient site is presented with an immersive and innovative multi-sensory interactive trip to the past. Copyright &copy; 2005 John Wiley & Sons, Ltd.
Visualization of molecular quantum dynamics: a molecular visualization tool with integrated Web3D and haptics
Authors: R. Andrew Davies, Nigel W. John, John N. MacDonald, Keith H. Hughes
Venue: Proceedings of the tenth international conference on 3D Web technology (2005)

The Department of Chemistry and the School of Informatics at the University of Wales, Bangor are working together to create tools for the visualization of molecular quantum dynamics. This paper presents the results of our initial work. A prototype Molecular Visualiser (MV) application has been developed based on Web3D standards, plus extensions for support of haptic interaction. MV provides the user with visualizations of molecular systems, potential energy surfaces, and wavepacket dynamics. These can be displayed in a web browser using VRML, or be delivered to a virtual environment in which haptic properties have been assigned based on the molecular dynamics of the system. The use of MV for both research and teaching is discussed.
Performance Evaluation of the Cray X1 Distributed Shared-Memory Architecture
Authors: Thomas H. Dunigan Jr., Jeffrey S. Vetter, James B. White III, Patrick H. Worley
Venue: IEEE Micro (2005)

The Cray X1 supercomputer's distributed shared memory presents a 64-bit global address space that is directly addressable from every MSP with an interconnect bandwidth per computation rate of 1 byte/flop. Our results show that this high bandwidth and low latency for remote memory accesses translate into improved application performance on important applications.