ppxscal/embedding_network huggingface dataset:
Multilinear Independent Components Analysis
Authors: M. Alex O. Vasilescu, Demetri Terzopoulos
Venue: Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05) - Volume 1 - Volume 01 (2005)

Independent Components Analysis (ICA) maximizes the statistical independence of the representational components of a training image ensemble, but it cannot distinguish between the different factors, or modes, inherent to image formation, including scene structure, illumination, and imaging. We introduce a nonlinear, multifactor model that generalizes ICA. Our Multilinear ICA (MICA) model of image ensembles learns the statistically independent components of multiple factors. Whereas ICA employs linear (matrix) algebra, MICA exploits multilinear (tensor) algebra. We furthermore introduce a multilinear projection algorithm which projects an unlabeled test image into the N constituent mode spaces to simultaneously infer its mode labels. In the context of facial image ensembles, where the mode labels are person, viewpoint, illumination, expression, etc., we demonstrate that the statistical regularities learned by MICA capture information that, in conjunction with our multilinear projection algorithm, improves automatic face recognition.
Approximating MIN 2-SAT and MIN 3-SAT
Authors: Adi Avidor, Uri Zwick
Venue: Theory of Computing Systems (2005)

We obtain substantially improved approximation algorithms for the MIN k-SAT problem, for k = 2,3. More specifically, we obtain a 1.1037-approximation algorithm for the MIN 2-SAT problem, improving a previous 1.5-approximation algorithm, and a 1.2136-approximation algorithm for the MIN 3-SAT problem, improving a previous 1.75-approximation algorithm for the problem. These results are obtained by adapting techniques that were previously used to obtain approximation algorithms for the MAX k-SAT problem. We also obtain some hardness of approximation results.
Evaluation of interference due to UWB hot spot on fixed wireless access systems: Research Articles
Authors: Romeo Giuliano, Gianluca Guidoni, Ibrahim Habib, Franco Mazzenga
Venue: Wireless Communications Mobile Computing (2004)

Ultra Wide Bandwidth (UWB) techniques are getting an increased importance due to their many features such as high bit rates availability, low power consumption and location capabilities. UWB technology enables the development of advanced wireless local area networks providing integrated multimedia services to nomadic users over hot-spot areas. The assessment of the possible interference caused by UWB devices on already existing narrowband and wideband systems is fundamental to ensure not-conflicting coexistence and, therefore, the acceptance of UWB technology worldwide. In this paper we analyze coexistence between an indoor UWB system and an outdoor fixed wireless access (FWA) system operating in the 3.5&ndash;5.0&thinsp;GHz band. We consider a realistic UWB master&#x002F;slave system architecture using pulse amplitude modulated spread spectrum signals for multiple access and we evaluate the UWB system interfering power in the FWA band accounting for the UWB power spectrum shape. Both upstream and downstream communication directions are analyzed. We show through computer simulation, that in many practical cases UWB system can coexist with FWA without causing any dangerous interference. Copyright &copy; 2004 John Wiley & Sons, Ltd.
Performance aspects of distributed caches using, TTL-based consistency
Authors: Edith Cohen, Eran Halperin, Haim Kaplan
Venue: Theoretical Computer Science (2005)

The web is the largest distributed database deploying time-to-live-based weak consistency. Each object has a lifetime-duration assigned to it by its origin server. A copy of the object fetched from its origin server is received with maximum time-to-live (TTL) that equals its lifetime duration. In contrast a copy obtained through a cache have shorter TTL since the age (elapsed time since fetched from the origin) is deducted from its lifetime duration. A request served by a cache constitutes a hit if the cache has a fresh copy of the object. Otherwise, the request is considered a miss and is propagated to another server. It is evident that the number of cache misses depends on the age of the copies the cache receives. Thus, a cache that sends requests to another cache would suffer more misses than a cache that sends requests directly to an authoritative server.In this paper, we model and analyze the effect of age on the performance of various cache configurations. We consider a low-level cache that fetches objects either from their origin servers or from other caches and analyze its miss-rate as function of its fetching policy. We distinguish between three basic fetching policies, namely, fetching always from the origin, fetching always from the same high-level cache, and fetching from a "random" high-level cache. We explore the relationships between these policies in terms of the miss-rate achieved by the low-level cache, both on worst-case sequences, and on sequences generated using particular probability distributions.Guided by web caching practice, we consider two variations of the basic policies. In the first variation the high-level cache uses pre-term refreshes to keep a copy with lower age. In the second variation the low-level cache uses extended lifetime duration. We analyze how these variations affect the miss-rates. Our theoretical results help to understand how age may affect the miss-rate, and imply guidelines for improving performance of web caches.
The Corporate Digital Divide: Determinants of Internet Adoption
Authors: Chris Forman
Venue: Management Science (2005)

The diffusion of Internet technology among firms is widely considered to be one of the primary factors behind the rapid economic growth of the 1990s. However, little systematic study has examined the variation in firm decisions to adopt the Internet. I explore the sources of this variation by examining Internet adoption decisions in a very large sample of organizations in the finance and services sector in 1998.I show how prior information technology (IT) investments and workplace organization decisions affect the returns to adopting simple and complex Internet technologies. I show that recent investments in client/server (C/S) networking applications have competing effects on the likelihood of Internet adoption. Such investments can slow adoption by acting as a short-run substitute or by creating "switching costs." Geographic dispersion of employees is complementary with Internet adoption, suggesting that Internet technology lowered internal coordination costs. Increases in organization size and external pressure also increase the likelihood of adoption.
Performance and Availability of Internet Data Centers
Authors: Daniel A. Menasce
Venue: IEEE Internet Computing (2004)

I've used previous columns to discuss several quality-of-service (QoS) metrics, including response time, throughput, and availability, in the context of Web scalability. In most of my past discussions, though, I treated these metrics in isolation; here, I'll discuss how performance and availability are interrelated by using an Internet data center (IDC) as a motivating example. IDCs provide the means for geographically distributed Internet users to tap into other computers and applications.
Flexible Particle Swarm Optimization Tasks for Reconfigurable Processor Arrays
Authors: Stefan Janson, Martin Middendorf
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 6 - Volume 07 (2005)

Multi task parallel processor arrays are a common machine architecture in which, typically, the tasks running in parallel occupy disjoint subarrays of the machine. On dynamically and partially reconfigurable processor arrays the tasks can be changed during run time. This is useful for online scenarios when the relative importance of tasks might change and therefore the assignment of computational resources to the tasks should be changed. Examples are optimization tasks in an online scenario in which the results of some tasks are needed earlier than expected at initialization. For such tasks the size of their subarrays must be increased because they need more computational resources to speed up. In this paper we design flexible Particle Swarm Optimization (PSO) algorithms for 2-dimensional reconfigurable processor arrays where the algorithms can change their size and have a good optimization behaviour. Since PSO is an iterative, individual-based optimization algorithm that relies upon interactions of neighbouring particles suitable for fine-grained parallel architectures. We propose a dynamic 2-dimensional hierarchical ordering of the particles within a tasks subarray so that the best particles are concentrated in the center. This gives the best particles the strongest influence on the swarm. A further advantage is that size reductions of the tasks can easily be done by cutting off the outer parts of the swarm which contain mainly the less good particles. It is experimentally shown that the proposed algorithms perform better than standard PSO algorithms under conditions with varying supply of computing resources that are available for the tasks. Moreover, also for conditions with constant supply of processing resources and no need for size changes the proposed algorithms perform well.
A Novel Deadlock Avoidance Algorithm and Its Hardware Implementation
Authors: Jaehwan Lee, Vincent John Mooney III
Venue: Proceedings of the international conference on Hardware/Software Codesign and System Synthesis: 2004 (2004)

This paper proposes a novel Deadlock Avoidance Algorithm (DAA) and its hardware implementation, the Deadlock Avoidance Unit (DAU), as an Intellectual Property (IP) core that provides a mechanism for very fast and automatic deadlock avoidance in MultiProcessor System-on-a-Chip (MPSoC) with multiple (e.g., 10) processing elements and multiple (e.g., 40) resources. The DAU avoids deadlock by not allowing any grant or request that leads to a deadlock. In case of livelock, the DAU asks one of the processes involved in the livelock to release resource(s) so that the livelock can also be resolved. We simulated two realistic examples that can benefit from the DAU, and demonstrated that the DAU not only avoids deadlock in a few clock cycles but also achieves a 37% speed-up of application execution time over avoiding deadlock in software. Finally, the SoC area overhead due to the DAU is small, under 0.01% in our example.
More Netflow Tools for Performance and Security
Authors: Carrie Gates, Michael Collins, Michael Duggan, Andrew Kompanek, Mark Thomas
Venue: Proceedings of the 18th USENIX conference on System administration (2004)

Analysis of network traffic is becoming increasingly important, not just for determining network characteristics and anticipating requirements, but also for security analysis. Several tool sets have been developed to perform analysis of flow-level network traffic, however none have had security as the primary goal of the analysis, nor has performance been a key consideration.In this paper we present a suite of tools for network traffic collection and analysis based on Cisco NetFlow. The two primary design considerations were performance and the ability to build richer models of traffic for security analysis. Thus the data structures and code have been optimized for use on very large networks with a large number of flows. Data filter rates are approximately 80 million records in less than 1.5 minutes on a Sun 4800.
The syntax or the story behind it?: a usability study of student work with computer-based programming environments in elementary science
Authors: Loucas Louca
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2005)

This is a descriptive case study investigating the use of two computer-based programming environments (CPEs), MicroWorlds™ Logo (MW) and Stagecast Creator™ (SC) for collaborative scientific modeling. The purpose of the study was to investigate and comparatively describe student approaches to scientific modeling through the use of textual or graphical program languages (PL). I analyzed student activities and conversations in two after-school clubs, one working with MW and the other with SC, using contextual inquiry, analysis of student conversation and artifact analysis. The findings suggest that student work with CPEs differed between different PL. Students used SC to create games (focusing on the overall story) whereas MW students used MW through a frame of formal programming. Programming in SC was much easier than MW, whereas reading code in MW was more tangible. Findings suggest that differences in student approaches to scientific modeling through programming need to be considered by educators seeking to engage students in such activities and software developers seeking to develop CPEs for young learners.
JiST: an efficient approach to simulation using virtual machines: Research Articles
Authors: Rimon Barr, Zygmunt J. Haas, Robbert van Renesse
Venue: Software&mdash;Practice Experience (2005)

Discrete event simulators are important scientific tools and their efficient design and execution is the subject of much research. In this paper, we propose a new approach for constructing simulators that leverages virtual machines and combines advantages from the traditional systems-based and language-based simulator designs. We introduce JiST, a Java-based simulation system that executes discrete event simulations both efficiently and transparently by embedding simulation semantics directly into the Java execution model. The system provides standard benefits that the modern Java runtime affords. In addition, JiST is efficient, out-performing existing highly optimized simulation runtimes. As a case study, we illustrate the practicality of the JiST framework by applying it to the construction of SWANS, a scalable wireless ad hoc network simulator. We simulate million node wireless networks, which represents two orders of magnitude increase in scale over what existing simulators can achieve on equivalent hardware and at the same level of detail. Copyright &copy; 2005 John Wiley & Sons, Ltd.As of this writing, the JiST and SWANS software distributions and documentation are available online [1]
Semiautomatic labelling of semantic features
Authors: Arantza Díaz de Ilarraza, Aingeru Mayor, Kepa Sarasola
Venue: Proceedings of the 19th international conference on Computational linguistics - Volume 1 (2002)

This paper presents the strategy and design of a highly efficient semiautomatic method for labelling the semantic features of common nouns, using semantic relationships between words, and based on the information extracted from an electronic monolingual dictionary. The method, that uses genus data, specific relators and synonymy information, obtains an accuracy of over 99% and a scope of 68,2% with regard to all the common nouns contained in a real corpus of over 1 million words, after the manual labelling of only 100 nouns.
Optimal data-space partitioning of spatial data for parallel I/O
Authors: Hakan Ferhatosmanoǧlu, Divyakant Agrawal, Ömer Eǧecioǧlu, Amr El Abbadi
Venue: Distributed and Parallel Databases (2005)

It is desirable to design partitioning methods that minimize the I/O time incurred during query execution in spatial databases. This paper explores optimal partitioning for two-dimensional data for a class of queries and develops multi-disk allocation techniques that maximize the degree of I/O parallelism obtained in each case. We show that hexagonal partitioning has optimal I/O performance for circular queries among all partitioning methods that use convex non-overlapping regions. An analysis and extension of this result to all possible partitioning techniques is also given. For rectangular queries, we show that hexagonal partitioning has overall better I/O performance for a general class of range queries, except for rectilinear queries, in which case rectangular grid partitioning is superior. By using current algorithms for rectangular grid partitioning, parallel storage and retrieval algorithms for hexagonal partitioning can be constructed. Some of these results carry over to circular partitioning of the data-which is an example of a non-convex region.
E-mail Subject Lines and Their Effect on Web Survey Viewing and Response
Authors: Stephen R. Porter Michael E. Whitcomb
Venue: Social Science Computer Review (2005)

This article investigates the effect of e-mail subject lines on survey viewing and survey response. Using two samples of students (low involvement with the survey sponsor and high involvement with the survey sponsor), the authors tested a variety of combinations of subject lines: the reason for the e-mail contact (survey), the sponsor of the e-mail (Liberal Arts University), a plea for help (request for assistance), and a blank subject line. The authors found a modest effect of subject line for the low-involvement sample, with blank subject lines yielding the highest response.
Simulated annealing heuristic for flow shop scheduling problems with unrelated parallel machines
Authors: Chinyao Low
Venue: Computers and Operations Research (2005)

This article addresses a multi-stage flow shop scheduling problem with unrelated parallel machines. Some practical processing restrictions such as independent setup and dependent removal times are taken into account as well. The objective is to minimize total flow time in the system. A simulated annealing (SA)-based heuristic is proposed to solve the addressed problem in a reasonable running time. The heuristic begins on a well-designed initial solution generator; then a simulated annealing procedure is applied for further improvement of the solution. To assure the quality and efficiency of the solution for the proposed SA-based heuristic, certain mechanisms are developed and introduced into the heuristic. The computational experimental results show that the proposed SA-based heuristic performs well with respect to accuracy and efficiency of solution.
An Efficient R-Mesh Implementation of LDPC Codes Message-Passing Decoder
Authors: Sharareh Babvey, Jose Alberto Fernandez-Zepeda, Anu G. Bourgeois, Steven W. McLaughlin
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 8 - Volume 09 (2005)

In this paper we propose a constant-time parallel algorithm for implementing the message-passing decoder of LDPC codes on a two dimensional RMesh, trying to keep the number of processors small. The R-Mesh provides dynamic reconfiguration, hardware reuse, and flexibility to problem changes. To decode a different code, we may simply set up the required connections between the bit-nodes and check-nodes by modifying the initialization phase of the R-Mesh algorithm. No extra wiring or hardware changes are required, as compared to other existing approaches. Moreover, the same hardware can implement the decoder in both probability and logarithm domains. We illustrate that the R-Mesh is an efficient model for parallel implementation of the decoder in terms of time complexity, flexibility to problem changes and simplicity of routing messages.
Stable Allocations in Distributed Real-Time Systems with Multiple Environmental Parameters and Replicable Applications
Authors: Hang Zhao, Dazhang Gu, Lonnie Welch, Frank Drews, David Juedes
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 2 - Volume 03 (2005)

This paper extends the previous work on the maximal allowable workload (MAW) problem by investigating a resource allocation problem for distributed real-time systems that contain replicable applications. The systems may use multiple resources of a single type and be affected by multiple environmental factors. The approach searches for a feasible allocation that maximizes a user defined metric of stability. Several algorithms were developed and experiments were conducted to demonstrate the relative strength of these algorithms. The results showed that Simulated Annealing provides results that are the closest to the optimal for maximizing environmental parameter settings. In addition modified greedy first fit is shown to be the best performing algorithm for finding feasible allocations.
Engaging computing: makin' it real for kids and undergrads
Authors: Fred Martin
Venue: Journal of Computing Sciences in Colleges (2004)

Engaging Computing makes computation real for students of all ages. Rather than operating on abstract data, software programs can use physical sensors for input, and drive lamps, motors, and sound as output. Computing is at the heart of projects that engage with the world.
Parallel and Reliable Execution of a WDR Algorithm in High Speed Networks
Authors: M. Marinov, D. Avresky, T. Nguyen
Venue: Proceedings of the 12th IEEE International Conference and Workshops on Engineering of Computer-Based Systems (2005)

This paper presents an idea for a parallel version of the WDR (Wavelet Difference Reduction) compression algorithm. An implementation of the idea is applied to the Nguyen-Chen-Walkerýs WDR codec and related analysis are demonstrated. The parallel WDR codec (PWDR) reaches up to 50 percent speedup compared to the original sequential implementation for some images. A reliable extension of the parallelized program and analyses of its performance have been presented.
Bias Superposition " An On-Line Test Strategy for a MEMS Based Conductivity Sensor
Authors: Carl Jeffrey, Zhou Xu, Andrew Richardson
Venue: Proceedings of the 10th IEEE European Symposium on Test (2005)

A novel on-line monitoring technique for a range of MEMS and integrated sensor systems is presented based on the injection of a test stimuli into the bias structure of transducer functions. The technique "Bias Superposition" utilises both signal injection and signal extraction techniques to achieve an indication of structural integrity of the transducer and interface. The technique has been successfully applied to a thick film conductance sensor.
Sweep and point and shoot: phonecam-based interactions for large public displays
Authors: Rafael Ballagas, Michael Rohs, Jennifer G. Sheridan
Venue: CHI '05 extended abstracts on Human factors in computing systems (2005)

This paper focuses on enabling interactions with large public displays using the most ubiquitous personal computing device, the mobile phone. Two new interaction techniques are introduced that use the embedded camera on mobile phones as an enabling technology. The "Point & Shoot" technique allows users to select objects using visual codes to set up an absolute coordinate system on the display surface instead of tagging individual objects on the screen. The "Sweep" technique enables users to use the phone like an optical mouse with multiple degrees of freedom and allows interaction without having to point the camera at the display. Prototypes of these interactions have been implemented and evaluated using modern mobile phone technologies. This proof of concept provides a performance baseline and gives valuable insights to guide future research and development. These techniques are intended to inspire and enable new classes of large public display applications.