ppxscal/embedding_network huggingface dataset:
Optimal Routing In Output-Queued Flexible Server Systems
Authors: Alexander L. Stolyar
Venue: Probability in the Engineering and Informational Sciences (2005)

We consider a queuing system with multitype customers and nonhomogeneous flexible servers, in the heavy traffic asymptotic regime and under a complete resource pooling (CRP) condition. For the input-queued (IQ) version of such a system (with customers being queued at the system &ldquo;entrance,&rdquo; one queue per each type), it was shown in the work of Mandelbaum and Stolyar that a simple parsimonious Gc&mgr; scheduling rule is optimal in that it asymptotically minimizes the system customer workload and some strictly convex queuing costs. In this article, we consider a different&mdash;output-queued (OQ)&mdash;version of the model, where each arriving customer must be assigned to one of the servers immediately upon arrival. (This constraint can be interpreted as immediate routing of each customer to one of the &ldquo;output queues,&rdquo; one queue per each server.) Consequently, the space of controls allowed for an OQ system is a subset of that for the corresponding IQ system.We introduce the MinDrift routing rule for OQ systems (which is as simple and parsimonious as Gc&mgr;) and show that this rule, in conjunction with arbitrary work-conserving disciplines at the servers, has asymptotic optimality properties analogous to those Gc&mgr; rule has for IQ systems. A key element of the analysis is the notion of system server workload, which, in particular, majorizes customer workload. We show that (1) the MinDrift rule asymptotically minimizes server workload process among all OQ-system disciplines and (2) this minimal process matches the minimal possible customer workload process in the corresponding IQ system. As a corollary, MinDrift asymptotically minimizes customer workload among all disciplines in either the OQ or IQ system.
Corporate re-orgs: poison or catalyst to HCI?
Authors: Kelly Braun, Klaus Kaasgaard, Stephanie Rosenbaum, Anna Wichansky
Venue: CHI '05 extended abstracts on Human factors in computing systems (2005)

Are you facing a corporate re-org? Re-orgs can create exciting opportunities for HCI groups, or good people's careers can be set back. This panel of HCI managers will consult on corporate reorganizations described by audience members. First, panelists with different perspectives discuss the roles of HCI resources during re-orgs. Then the panel will address audience questions on how to be proactive about organizational changes. (Send your questions to stephanie@teced.com by March 15th.) This panel will be of special interest to the industry segment of the CHI community-and also to academics who are educating future practitioners.
Technical Reports
Authors: William Hefley
Venue: ACM SIGCHI Bulletin (1992)

At this time, we make "complimentary" copies of Rensselaer Computer Science Department technical reports available upon request. Please send requests to: Ora Schongar, Adm. Secretary, Computer Science Department, Amos Eaton 119, Rensselaer Polytechnic Institute, Troy, New York 12180--3590;+1--518--276--8412; Fax: +1--518--276--4033; E-mail: schongar@cs.rpi.edu
At-Speed Transition Fault Testing With Low Speed Scan Enable
Authors: Nisar Ahmed, C. P. Ravikumar, Mohammad Tehranipoor, Jim Plusquellic
Venue: Proceedings of the 23rd IEEE VLSI Test Symposium (2005)

With today's design size in millions of gates and working frequency in gigahertz range, at-speed test is crucial. The launch-off-shift method has several advantages over the launch-off-capture but imposes strict requirements on transition fault testing due to at-speed scan enable signal. A novel scan-based at-speed test is proposed which generates multiple local fast scan enable signals. The scan enable control information is encapsulated in the test data and transferred during the scan operation. A new scan cell, referred to as last transition generator (LTG), is inserted in the scan chains to generate the fast local scan enable signal. The proposed technique is robust, practice-oriented and suitable for use in an industrial flow.
Computer science and the mathematics genealogy project
Authors: Harry B. Coonce
Venue: ACM SIGACT News (2004)

From the book of Genesis to the TCS genealogy of Ian Parberry [1] folks have been inquisitive about their roots. In academic disciplines --- such as computer science, mathematics, statistics, etc. --- people are frequently interested in their academic heritage. 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
Building an open source meta-search engine
Authors: A. Gulli, A. Signorini
Venue: Special interest tracks and posters of the 14th international conference on World Wide Web (2005)

In this short paper we introduce Helios, a flexible and efficient open source meta-search engine. Helios currently runs on the top of 18 search engines (in Web, Books, News, and Academic publication domains), but additional search engines can be easily plugged in. We also report some performance mesured during its development.
The affine representation theorem for abstract convex geometries
Authors: Kenji Kashiwabara, Masataka Nakamura, Yoshio Okamoto
Venue: Computational Geometry: Theory and Applications (2005)

A convex geometry is a combinatorial abstract model introduced by Edelman and Jamison which captures a combinatorial essence of "convexity" shared by some objects including finite point sets, partially ordered sets, trees, rooted graphs. In this paper, we introduce a generalized convex shelling, and show that every convex geometry can be represented as a generalized convex shelling. This is "the representation theorem for convex geometries" analogous to "the representation theorem for oriented matroids" by Folkman and Lawrence. An important feature is that our representation theorem is affine-geometric while that for oriented matroids is topological. Thus our representation theorem indicates the intrinsic simplicity of convex geometries, and opens a new research direction in the theory of convex geometries.
Shaped lattice graphs as models of the multiprocessor computer systems
Authors: P. P. Parkhomenko
Venue: Automation and Remote Control (2005)

A new family of the uniform ordinary graphs named the shaped lattice graphs was proposed and studied. As applied to the structural modeling of the multiprocessor computer systems, they have two useful characteristics such as high flexibility at choosing their size (number of vertices) and possibility of obtaining small (down to d = 2) diameters independently of the graph size. The method of cycle definition and transformation by the ring sequences of edge weights, which was previously proposed for the binary hypercubes and other Cayley graphs, was extended to the shaped lattice graphs.
Fast communication: wideband cyclic MUSIC algorithms
Authors: Huiqin Yan, H. Howard Fan
Venue: Signal Processing (2005)

In this paper, we propose two cyclic-MUSIC-like DOA estimation algorithms for wideband cyclostationary signals, the averaged cyclic MUSIC (ACM) algorithm and the extended wideband cyclic MUSIC (EWCM) algorithm. Compared with the existing spectral correlation signal subspace fitting (SC-SSF) algorithm, which was also developed for wideband cyclostationary signals, our new methods have more relaxed requirements on the signals. Simulation results show that under those circumstances, both our methods are superior to the existing SC-SSF algorithm.
An OWL-based extensible transcoding system for mobile multi-devices
Authors: I. -Ching Hsu, Shang-Juh Kao
Venue: Journal of Information Science (2005)

Due to the rapid Internet development, an answer to the challenging question of how to automatically convert heterogeneous information into the desired XML format that can be accepted by a designated device is urgently requested. In this paper, we propose an OWL-based extensible trans-coding system (OETS) which is based on an extensible transcoding policy infrastructure, with a hierarchical structure of ontologies, and can automatically render an HTML document in mobile devices. In order to create common knowledge of OETS, we develop two top level ontologies: procedural sensor/effector ontology (PSEO) and markup file taxonomy ontology (MFTO). PSEO combines with situated logic to support sensor/effector procedures attached to an ontology class, while MFTO supports the markup file and structural components classification. Developers can exploit the extensible transcoding capability of OETS to satisfy various layout-specific structures of HTML pages by providing dedicated domain ontologies.
Elastic Translation Invariant Matching of Trajectories
Authors: Michail Vlachos, George Kollios, Dimitrios Gunopulos
Venue: Machine Learning (2005)

We investigate techniques for analysis and retrieval of object trajectories. We assume that a trajectory is a sequence of two or three dimensional points. Trajectory datasets are very common in environmental applications, mobility experiments, video surveillance and are especially important for the discovery of certain biological patterns. Such kind of data usually contain a great amount of noise, that makes all previously used metrics fail. Therefore, here we formalize non-metric similarity functions based on the Longest Common Subsequence (LCSS), which are very robust to noise and furthermore provide an intuitive notion of similarity between trajectories by giving more weight to the similar portions of the sequences. Stretching of sequences in time is allowed, as well as global translating of the sequences in space. Efficient approximate algorithms that compute these similarity measures are also provided. We compare these new methods to the widely used Euclidean and Dynamic Time Warping distance functions (for real and synthetic data) and show the superiority of our approach, especially under the strong presence of noise. We prove a weaker version of the triangle inequality and employ it in an indexing structure to answer nearest neighbor queries. Finally, we present experimental results that validate the accuracy and efficiency of our approach.
Complete automatic Q tuning system on a chip
Authors: Roghoyeh Salmeh, Brent J. Maundy
Venue: Integration, the VLSI Journal (2005)

As the need for filters in high frequency applications increases so too are the requirements for high accuracy. Design of accurate filters requires some kind of tuning scheme to be added in the filter circuitry. In this paper we present an innovative approach to VLSI implementation of Q tuning of analog lowpass/ highpass filters based on the magnitude locked loop method. The proposed method uses the LMS algorithm to adaptively compensate changes in input amplitude and Frequency. A fully differential multiplier and a new linearly tuned OTA are designed to implement the automatic control loop in the integrated circuit. The tuning system was implemented in a CMOS 0.18 µm technology in a master-slave configuration.
Book Review: Symbolic Computing with Lisp and Prolog by Robert A Mueller and Rex L. Page (John Wiley and Sons)
Venue: ACM SIGART Bulletin (1990)

This book covers the major portions of symbolic computing and denotational (declarative) programming. The main thrust of the authors is to contrast and compare the two major tools for symbolic computing, viz. Lisp and Prolog. For this purpose, the book has been sub-divided into the following four major sections:Section I: Lisp;Section II: Prolog;Section III: Lisp vs Prolog; andSection IV: Applications.Each of these sections is further sub-divided into several chapters covering different aspects of the topic. Every chapter contains a variety of examples, solved respectively in Lisp or Prolog in the first two sections and in both the languages in the last two sections. Also, each of the chapters is followed by a chapter summary, bibliography notes, and a set of exercises. The spectrum of topics covered for each language includes, notation for data and variables, relations containing facts, list manipulation, recursion, unification, debugging, input/output, backtracking, higher-order functions, and manipulation of numbers.
Application of Machine Learning Techniques to Web-Based Intelligent Learning Diagnosis System
Authors: Chenn-Jung Huang, Ming-Chou Liu, San-Shine Chu, Chin-Lun Cheng
Venue: Proceedings of the Fourth International Conference on Hybrid Intelligent Systems (2004)

This work proposes an intelligent learning diagnosis system that supports a Web-based thematic learning model, which aims to cultivate learners' ability of knowledge integration by giving the learners the op-portunities to select the learning topics that they are interested, and gain knowledge on the specific topics by surfing on the Internet to search related learning course-ware and discussing what they have learned with their colleagues. Based on the log files that record the learners' past online learning behavior, an intelligent diagnosis system is used to give appropriate learning guidance to assist the learners in improving their study behaviors and grade online class participation for the instructor. The achievement of the learners' final reports can also be predicted by the diagnosis system accurately. Our experimental results reveal that the proposed learn-ing diagnosis system can efficiently help learners to expand their knowledge while surfing in cyberspace Web-based "theme-based learning" model.
Partitioning of Web graphs by community topology
Authors: Hidehiko Ino, Mineichi Kudo, Atsuyoshi Nakamura
Venue: Proceedings of the 14th international conference on World Wide Web (2005)

We introduce a stricter Web community definition to overcome boundary ambiguity of a Web community defined by Flake, Lawrence and Giles [2], and consider the problem of finding communities that satisfy our definition. We discuss how to find such communities and hardness of this problem.We also propose Web page partitioning by equivalence relation defined using the class of communities of our definition. Though the problem of efficiently finding all communities of our definition is NP-complete, we propose an efficient method of finding a subclass of communities among the sets partitioned by each of n-1 cuts represented by a Gomory-Hu tree [10], and partitioning a Web graph by equivalence relation defined using the subclass.According to our preliminary experiments, partitioning by our method divided the pages retrieved by keyword search into several different categories to some extent.
Towards On-Line Testing of MEMS Using Electro-Thermal Excitation
Authors: F. Mailly, F. Azais, N. Dumas, L. Latorre, P. Nouet
Venue: Proceedings of the 10th IEEE European Symposium on Test (2005)

This paper presents an electro-thermal on-line testing procedure applied to a MEMS magnetometer. The basic idea consists in (i) using electro-thermal excitation to superimpose thermal variations to the normal operating mode and (ii) processing the sensor output to extract the thermally-induced signal. In this work, we investigate the possibility of using a modulation of the excitation signal to produce a low-frequency thermally-based signal at the output of the Wheatstone bridge. Investigations using high-level simulations are conducted to determine appropriate test stimulus and suitable system architecture.
Evolution of virtual libraries in Nigeria: myth or reality?
Authors: Okon E. Ani
Venue: Journal of Information Science (2005)

The article investigates factors that may make the Nigeria Virtual Library Project a myth or reality. Questionnaires were used for data collection, using 22 University Librarians in federal universities as respondents, and 14 (64%) University Librarians completed the questionnaires. Three indicators were used to determine the myth or reality of evolving virtual libraries in Nigeria: availability of information infrastructures, human capacity building programmes in ICT, and level of funding of university libraries. Nine (64%) of the libraries have relevant information infrastructures, 12 (86%) are involved in human capacity building programmes, 11 (79%) affirm that the level of funding for university libraries is low. The article concludes that evolution of virtual libraries is feasible and real in Nigeria.
Matrix register file and extended subwords: two techniques for embedded media processors
Authors: Asadollah Shahbahrami, Ben Juurlink, Stamatis Vassiliadis
Venue: Proceedings of the 2nd conference on Computing frontiers (2005)

In this paper we employ two techniques suitable for embedded media processors. The first technique, extended subwords, uses four extra bits for every byte in a media register. This allows many SIMD operations to be performed without overflow and avoids packing/unpacking conversion overhead because of mismatch between storage and computational formats. The second technique, the Matrix Register File (MRF), allows flexible row-wise as well as column-wise access to the register file. It is useful for many block-based multimedia kernels such as (I)DCT, 2x2 Haar Transform, and pixel padding. In addition, we propose a few new media instructions. We employ Modified MMX (MMMX), MMX with extended subwords, to evaluate these techniques. Our results show that MMMX combined with an MRF reduces the dynamic number of instructions by up to 80% compared to other multimedia extensions such as MMX
A case for dynamic selection of replication and caching strategies
Authors: Swaminathan Sivasubramanian, Guillaume Pierre, Maarten van Steen
Venue: Web content caching and distribution: proceedings of the 8th international workshop (2004)

Replication and caching strategies are being used to reduce user perceived delay and wide area network traffic. Numerous such strategies have been proposed to manage replication while maintaining consistency among the replicas. In earlier research, we demonstrated that no single strategy can perform optimal for all documents, and proposed a system where strategies are selected on a per-document basis using trace-driven simulation techniques. In this paper, we demonstrate the need for continuous dynamic adaptation of strategies using experiments conducted on our department Web traces. We also propose two heuristics, Simple and Transition, to perform this dynamic adaptation with reduced simulation cost. In our experiments, we find that Transition heuristic reduces simulation cost by an order of magnitude while maintaining high accuracy in optimal strategy selection.
Kernel-Based Bayesian Filtering for Object Tracking
Authors: Bohyung Han, Ying Zhu, Dorin Comaniciu, Larry Davis
Venue: Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05) - Volume 1 - Volume 01 (2005)

Particle filtering provides a general framework for propagating probability density functions in non-linear and non-Gaussian systems. However, the algorithm is based on a Monte Carlo approach and sampling is a problematic issue, especially for high dimensional problems. This paper presents a new kernel-based Bayesian filtering framework, which adopts an analytic approach to better approximate and propagate density functions. In this framework, the techniques of density interpolation and density approximation are introduced to represent the likelihood and the posterior densities by Gaussian mixtures, where all parameters such as the number of mixands, their weight, mean, and covariance are automatically determined. The proposed analytic approach is shown to perform sampling more ef- ficiently in high dimensional space. We apply our algorithm to real-time tracking problems, and demonstrate its performance on real video sequences as well as synthetic examples.
Synopses for query optimization: a space-complexity perspective
Authors: Raghav Kaushik, Raghu Ramakrishnan, Venkatesan T. Chakaravarthy
Venue: Proceedings of the twenty-third ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2004)

Database systems use precomputed synopses of data to estimate the cost of alternative plans during query optimization. A number of alternative synopsis structures have been proposed, but histograms are by far the most commonly used. While histograms have proved to be very effective in (cost estimation for) single-table selections, queries with joins have long been seen as a challenge; under a model where histograms are maintained for individual tables, a celebrated result of Ioannidis and Christodoulakis observes that errors propagate exponentially with the number of joins in a query.In this paper, we make two main contributions. First, we study the space complexity of using synopses for query optimization from a novel information-theoretic perspective. In particular, we offer evidence in support of histograms for single-table selections, and illustrate their limitations for join queries. Second, for a broad class of common queries involving joins (specifically, all queries involving only key-foreign key joins) we show that the strategy of storing a small pre-computed sample of the database yields probabilistic guarantees that are almost space-optimal, in the sense that in order to provide the same guarantee as sampling, any strategy requires almost the same amount of space. This is an important property if these samples are to be used as database statistics. This is the first such optimality result, to our knowledge, and suggests that pre-computed samples might be an effective way to circumvent the error propagation problem for queries with key-foreign key joins. We support this result empirically through an experimental study that demonstrates the effectiveness of pre-computed samples, and also shows the increasing difference in the effectiveness of samples versus multi-dimensional histograms as the number of joins in the query grows.
Clutter Invariant ATR
Authors: Dmitri Bitouk Michael I. Miller
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2005)

One of the central problems in Automated Target Recognition is to accommodate the infinite variety of clutter in real military environments. The principle focus of our paper is on the construction of metric spaces where the metric measures the distance between objects of interest invariant to the infinite variety of clutter. Such metrics are formulated using second-order random field models. Our results indicate that this approach significantly improves detection/classification rates of targets in clutter.
Detecting Abnormal Gait
Authors: Christian Bauckhage, John K. Tsotsos, Frank E. Bunn
Venue: Proceedings of the 2nd Canadian conference on Computer and Robot Vision (2005)

Analyzing human gait has become popular in computer vision. So far, however, contributions to this topic almost exclusively considered the problem of person identification. In this paper, we will view gait analysis from a different angle and shall examine its use as a means to deduce the physical condition of people. Understanding the detection of unusual movement patterns as a two class problem leads to the idea of using support vector machines for classification. We will thus present a homeomorphisms between 2D lattices and binary shapes that provides a robust vector space embedding of body silhouettes. Experimental results will underline that feature vectors obtained from this scheme are well suited to detect abnormal gait. Wavering, faltering, and falling can be detected reliably across individuals without tracking or recognizing limbs or body parts.