ppxscal/embedding_network huggingface dataset:
A partial test of the task-medium fit proposition in a group support system environment
Authors: Bernard C. Y. Tan, Kwok-kee Wei, Choon-Ling Sia, Krishnamurthy S. Raman
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (1999)

A laboratory experiment was carried out to partially test the task-medium fit proposition in a GSS environment. Communication medium was varied using a face-to-face GSS and a dispersed GSS setting. Task type was varied using an intellective and a preference task. Group decision outcome variables of interest were (actual and perceived) decision quality, decision time, decision satisfaction, and decision process satisfaction. With the intellective task, there were no significant differences between face-to-face GSS and dispersed GSS groups for all group decision outcome variables. With the preference task, face-to-face GSS groups performed significantly better than dispersed GSS groups for all group decision outcome variables. These findings suggest that group decision outcomes in a GSS environment tend to be adversely affected when the communication medium is too lean for the task but not when the communication medium is too rich for the task. Consequences of providing groups with too rich and too lean a communication medium for their task are discussed. Implications of these findings, and other related results, for practice and for future revisions of media richness theory are explored.
A Theory of Single-Viewpoint Catadioptric Image Formation
Authors: Simon Baker, Shree K. Nayar
Venue: International Journal of Computer Vision (1999)

Conventional video cameras have limited fields of view which make them restrictive for certain applications in computational vision. A catadioptric sensor uses a combination of lenses and mirrors placed in a carefully arranged configuration to capture a much wider field of view. One important design goal for catadioptric sensors is choosing the shapes of the mirrors in a way that ensures that the complete catadioptric system has a single effective viewpoint. The reason a single viewpoint is so desirable is that it is a requirement for the generation of pure perspective images from the sensed images. In this paper, we derive the complete class of single-lens single-mirror catadioptric sensors that have a single viewpoint. We describe all of the solutions in detail, including the degenerate ones, with reference to many of the catadioptric systems that have been proposed in the literature. In addition, we derive a simple expression for the spatial resolution of a catadioptric sensor in terms of the resolution of the cameras used to construct it. Moreover, we include detailed analysis of the defocus blur caused by the use of a curved mirror in a catadioptric sensor.
Detecting Exitory Stuck-At Faults in Semimodular Asynchronous Circuits
Authors: Michael J. Liebelt, Neil Burgess
Venue: IEEE Transactions on Computers (1999)

Abstract—Beerel [1] showed that semimodular asynchronous circuits are totally self-checking with respect to multiple output stuck-at faults that are nonexitory and nonsubstitutional. We show that, in circuits with atomic gate implementations, it is possible to ensure that all exitory multiple output stuck-at faults will cause the circuit to halt.
Concurrent D-algorithm on reconfigurable hardware
Authors: Fatih Kocan, Daniel G. Saab
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

In this paper, a new approach for generating test vectors that detects faults in combinational circuits is introduced. The approach is based on automatically designing a circuit which implements the D-algorithm, an Automatic Test Pattern Generation (ATPG) algorithm, specialized for the combinational circuit. Our approach exploits fine-grain parallelism by performing the following in three clock cycles: direct backward/forward implications, conflict checking, selecting next gate to propagate fault or to justify a line, decisions on gate inputs, loading the state of the circuit after backup. In this paper, we show the feasibility of this approach in terms of speed, and how it compares with software based techniques.
Spectral Element Discretization of the Circular Driven Cavity, Part I: The Laplace Equation
Authors: C. Bernardi, A. Karageorghis
Venue: SIAM Journal on Numerical Analysis (1999)

This paper is devoted to the spectral element discretization of the Laplace equation in a disk when provided with discontinuous boundary data. Relying on an appropriate variational formulation, we propose a discrete problem and prove its convergence. The use of weighted Sobolev spaces to treat the discontinuity of the boundary conditions also allows for improving the order of convergence. The results of the numerical experiments we present are in agreement with the theoretical ones.
Median Graphs and Triangle-Free Graphs
Authors: Wilfried Imrich, Sandi Klavzar, Henry Martyn Mulder
Venue: SIAM Journal on Discrete Mathematics (1999)

Let M(m,n) be the complexity of checking whether a graph G with medges and n vertices is a median graph. We show that the complexity of checking whether Gis triangle-free is at most O(M(m,m)). Conversely, we prove that the complexity of checking whether a given graph is a median graph is at most O(m log n + T(m log n,n)), where T(m,n) is the complexity of finding all triangles of the graph. We also demonstrate that, intuitively speaking, there are as many median graphs as there are triangle-free graphs. Finally, these results enable us to prove that the complexity of recognizing planar median graphs is linear.
Fast MPEG-4 Motion Estimation: Processor Based and Flexible VLSI Implementations
Authors: Peter M. Kuhn
Venue: Journal of VLSI Signal Processing Systems (1999)

MPEG-4 is a new multimedia standard combining interactivity, object-based natural and synthetic digital video, audio and computer-graphics. For the implementation of the video part of the MPEG-4 standard a high degree of flexibility is required, where the motion estimation requires the highest part of the computational power. Therefore, in this paper fast algorithms for MPEG-4 motion estimation are evaluated in terms of visual quality and computational power requirements for processor based implementations. Due to the object-based nature of MPEG-4 also new VLSI architectures for MPEG-4 motion estimation are required. Therefore known motion estimation architectures are evaluated on their capability of being modified for MPEG-4 support. Based on this evaluation a new dedicated, but flexible MPEG-4 motion estimation architecture targeted for low-power handheld applications is presented, which resulted to be advantageous to processor based implementations by magnitudes of order.
On the Stability of a Partitioning Algorithm for Tridiagonal Systems
Authors: Plamen Yalamov, Velisar Pavlov
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

Componentwise error analysis for a parallel partitioning algorithm for tridiagonal systems is presented. Bounds on the equivalent perturbations are obtained, depending on three constants. Then bounds on the forward error are presented as well, depending on two types of condition numbers. Estimates on the first constant come directly from the roundoff error analysis of the tridiagonal Gaussian elimination [N. Higham, SIAM J. Matrix Anal. Appl., 11 (1990), pp. 521--530]. In the present paper, the second and third constants are bounded for some special classes of matrices, i.e., diagonally dominant (row or column), symmetric positive definite, M-matrices, and totally nonnegative.One of the features of the analysis is that the exact forward and backward errors are bounded, not just their first order approximations, with respect to the machine precision. In all the bounds, the linear terms are given separately to show that the terms of higher order are small enough.
An unslotted multichannel channel-access protocol for distributed direct-sequence networks
Authors: Arvind R. Raghavan, Carl W. Baum
Venue: Mobile Networks and Applications (2000)

A multichannel reservation-based channel-access protocol is investigated in this paper. The available system bandwidth is divided into distinct frequency channels. Under the protocol, one channel (the control channel) is used to exchange reservation messages and the remaining channels (the traffic channels) are used for information-bearing traffic. The performance of this scheme is compared to that of a single-channel reservation-based protocol. A simple contention-based slotted-Aloha protocol is also considered. Performance results take into account the effects of multiple-access interference on acquisition and packet errors. Results show that the reservation-based approach is advantageous under conditions of high traffic. In addition, a pacing mechanism that mitigates multiple-access interference and promotes fairness is described, and results are presented that demonstrate its effectiveness.
A test of task-technology fit theory for group support systems
Authors: Ilze Zigurs, Bonnie K. Buckland, James R. Connolly, E. Vance Wilson
Venue: ACM SIGMIS Database (1999)

Group support systems (GSS) provide both promise and puzzlement. Experimental studies of different systems over the years have resulted in conflicting findings --- sometimes enhancing group performance, at other times having no effect, and occasionally even resulting in worse performance for GSS-supported groups than for traditional groups. Researchers have speculated that the mixed results are due to a poor fit of the GSS with the group's task. A recent model of task-technology fit has provided a theoretical perspective from which to test this issue. In this paper, a theory of task-technology fit is tested by applying it to a selected set of published GSS experiments. Key constructs in the theory are operationalized via coding instruments, and the application of the coding scheme provides support for the theory.
Systematic and automated discovery of patterns in PROSITE families
Authors: Reece Hart, Ajay K. Royyuru, Gustavo Stolovitzky, Andrea Califano
Venue: Proceedings of the fourth annual international conference on Computational molecular biology (2000)

PROSITE is a method for protein classification which relies on a database of biologically significant sites and patterns in protein sequences. Most patterns in PROSITE have been gathered by a a labor intensive combination of experimental characterization of functional residues and sequence alignment. In this paper we present a new and efficient supervised learning procedure, based on the Splash deterministic pattern discovery algorithm and on a framework to assess the statistical significance of patterns. We demonstrate its application to the fully automatic discovery of patterns in 974 PROSITE families. For these families, Splash generates patterns with better specificity and/or sensitivity in 28%, identical statistics in 48%, and worse statistics in 15% of the cases; for the remaining families, patterns exhibited mixed behavior. Second, we have characterized the amount of overlap, on the sequences, between newly discovered patterns and those in PROSITE. In about 75% of the cases, Splash patterns identify sequence sites that overlap more than 50% with those reported in PROSITE. Of the 272 patterns which perform strictly better than the corresponding PROSITE pattern, 178 show more than 70% overlap with the PROSITE pattern. Third, our results suggest that the statistical significance of discovered patterns correlates well with their biological significance. Finally, we use the trypsin subfamily of serine proteases to illustrate the use of this method to exhaustively discover all motifs in a family that are statistically and biologically significant. The complete analysis is sufficiently rapid, taking less than a day for all PROSITE families, to enable the use this methodology for routine curation of existing motif and profile databases.
Detecting Embedded Networks in LP Using GUB Structures and IndependentSet Algorithms
Authors: Nalân Gülpinar, Gregory Gutin, Gautam Mitra, István Maros
Venue: Computational Optimization and Applications (2000)

In this paper, we present an alternative multi-stage generalized upper bounds (GUB) based approach for detecting an embedded pure network structure in an LP problem. In order to identify a GUB structure, we use two different approaches&semi; the first is based on the notion of Markowitz merit count and the second exploits independent sets in the corresponding graphs. Our computational experiments show that the multi-stage GUB algorithm based on these approaches performs favourably when compared with other well known algorithms.
The Height and Size of Random Hash Trees and Random Pebbled Hash Trees
Authors: Luc Devroye
Venue: SIAM Journal on Computing (1999)

The random hash tree and the N-tree were introduced by Ehrlich in 1981. In the random hash tree, n data points are hashed to values X1, . . . , Xn, independently and identically distributed random variables taking values that are uniformly distributed on [0,1]. Place the Xi's in n equal-sized buckets as in hashing with chaining. For each bucket with at least two points, repeat the same process, keeping the branch factor always equal to the number of bucketed points. If Hn is the height of tree obtained in this manner, we show that Hn/log2 n \to 1 in probability. We also show that the expected number of nodes in the random hash tree and random pebbled hash tree is asymptotic to 2.3020238 . . . n and 1.4183342. . . n, respectively.
A New Algorithm for the Decentralized Aggregation Problem
Authors: Akhil Kumar
Venue: Distributed and Parallel Databases (1999)

This paper describes a new algorithm for solving the distributed aggregation problem in which individual values from N nodes have to be aggregated in an associative and commutative manner, and the final result must be either computed at all sites or communicated to them. Our algorithm has a message-delay product of &Theta;(dN(N^)) where N is the number of nodes, and d is a parameter that corresponds to the number of dimensions of the hypercube into which the nodes are logically organized. This reflects an improvement upon existing algorithms by a factor of d. The algorithm can be initiated by any node, and works by creating multiple parallel streams that collect partial aggregates and finally converge at a node to compute the final result.
An analytic approach to significance assessment in local sequence alignment with gaps
Authors: R. Bundschuh
Venue: Proceedings of the fourth annual international conference on Computational molecular biology (2000)

A detailed study of the Smith-Waterman alignment algorithm is performed in order to find an analytical approach to the problem of assessing the statistical significance of local alignments with gaps. The significance is shown to be given in terms of an eigenvalue equation which captures the dynamics of the much simpler global alignment algorithm. This eigenvalue equation is then explicitly solved for a simple scoring system and the resulting significance estimations are verified by a comparison to extensive numerical simulations
Resource Scaling Effects on MPP Performance: The STAP Benchmark Implications
Authors: Kai Hwang, Cho-Li Wang, Choming Wang, Zhiwei Xu
Venue: IEEE Transactions on Parallel and Distributed Systems (1999)

Presently, massively parallel processors (MPPs) are available only in a few commercial models. A sequence of three ASCI Teraflops MPPs has appeared before the new millennium. This paper evaluates six MPP systems through STAP benchmark experiments. The STAP is a radar signal processing benchmark which exploits regularly structured SPMD data parallelism. We reveal the resource scaling effects on MPP performance along orthogonal dimensions of machine size, processor speed, memory capacity, messaging latency, and network bandwidth. We show how to achieve balanced resources scaling against enlarged workload (problem size). Among three commercial MPPs, the IBM SP2 shows the highest speed and efficiency, attributed to its well-designed network with middleware support for single system image. The Cray T3D demonstrates a high network bandwidth with a good NUMA memory hierarchy. The Intel Paragon trails far behind due to slow processors used and excessive latency experienced in passing messages. Our analysis projects the lowest STAP speed on the ASCI Red, compared with the projected speed of two ASCI Blue machines. This is attributed to slow processors used in ASCI Red and the mismatch between its hardware and software. The Blue Pacific shows the highest potential to deliver scalable performance up to thousands of nodes. The Blue Mountain is designed to have the highest network bandwidth. Our results suggest a limit on the scalability of the distributed shared-memory (DSM) architecture adopted in Blue Mountain. The scaling model offers a quantitative method to match resource scaling with problem scaling to yield a truly scalable performance. The model helps MPP designers optimize the processors, memory, network, and I/O subsystems of an MPP. For MPP users, the scaling results can be applied to partition a large workload for SPMD execution or to minimize the software overhead in collective communication or remote memory update operations. Finally, our scaling model is assessed to evaluate MPPs with benchmarks other than STAP.
Dea Duality on Returns to Scale (Rts) in Production and Cost Analyses: An Occurrence of Multiple Solutions and Differences Between Production-Based and Cost-Based Rts Estimates
Authors: M. S. Krishnan, Venkatram Ramaswamy, Mary C. Meyer, Paul Damien, Emmanuel Thanassoulis, Hemant K. Bhargava, Toshiyuki Sueyoshi
Venue: Management Science (1999)

This article discusses the concept of RTS (Returns To Scale) in the framework of DEA (Data Envelopment Analysis) production and cost analyses, focusing on an occurrence of multiple solutions and how to deal with such a difficulty. Dual relationships between production-based and cost-based RTS estimates are also theoretically discussed in this study.
Note on Perturbation Theory for Algebraic Riccati Equations
Authors: M. Konstantinov, P. Petkov
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

The expressions for the induced norms of two complex matrix operators, given in [J.-G. Sun, SIAM J. Matrix Anal. Appl., 19 (1998), pp. 39--65], must be corrected. In this note we give the true values of these induced norms, which are involved in the perturbation analysis of matrix algebraic Riccati equations in the complex domain.
Using Specific Displacements to Analyze Motion without Calibration
Authors: T. Viéville, D. Lingrand
Venue: International Journal of Computer Vision (1999)

Considering the field of un-calibrated image sequences and self-calibration, this paper analyzes the use of specific displacements (such as fixed axis rotation, pure translations,...) or specific sets of camera parameters. This allows to induce affine or metric constraints, which can lead to self-calibration and 3D reconstruction.A uniformed formalism for such models already developed in the literature plus some novel models are developed here. A hierarchy of special situations is described, in order to tailor the most appropriate camera model to either the actual robotic device supporting the camera, or to tailor the fact we only have a reduced set of data available.This visual motion perception module leads to the estimation of a minimal 3D parameterization of the retinal displacement for a monocular visual system without calibration, and leads to self-calibration and 3D dynamic analysis.The implementation of these equations is analyzed and experimented.
Bringing Community Involvement into a Cretan Primary/Hospital Care Center: An Evaluation of Population Habits and Attitudes Toward Health Care
Authors: Marios Chatziarsenis, Christos Lionis, Eleni Makri, Kiki Sapouna, Michael Fioretos, Tomas Faresjö, Manolis Mavromanolakis, Jean Vlachonikolis, Erik Trell
Venue: Journal of Medical Systems (1999)

In a small Cretan township hospital combining secondary and primary care, a questionnaire was distributed to a consecutive visitor sample. The questionnaire requested information on the participants' personal smoking and other life habits, perceptions and expectations of the delivery of the health care services, and attitudes toward their own doctors and others who provide various health services. Three hundred and one individuals of both sexes who were 15 years and older participated in the study (participation rate, more than 97%). An interesting and varied response was recorded, covering a wide range of perceptions, opinions, and attitudes not only toward the services, but also toward the staff. Although a high confidence in and appreciation of both the primary care and hospital sections appeared in the study results, these attitudes should not be allowed to deteriorate. Therefore, specific actions should be undertaken: constant upgrading of the existing organizational context, implementation of promotional and educational programs, and use of the questionnaire as an effective tool for periodically assessing the population's attitudes, experiences, and expectations.
A no-busy-wait balanced tree parallel algorithmic paradigm
Authors: Uzi Vishkin
Venue: Proceedings of the twelfth annual ACM symposium on Parallel algorithms and architectures (2000)

Suppose that a parallel algorithm can include any number of parallel threads. Each thread can proceed without ever having to busy wait to another thread. A thread can proceed till its termination, but no new threads can be formed. What kind of problems can such restrictive algorithms solve and still be competitive in the total number of operations they perform with the fastest serial algorithm for the same problem? Intrigued by this informal question, we considered one of the most elementary parallel algorithmic paradigms, that of balanced binary trees. The main contribution of this paper is a new balanced (not necessarily binary) tree no-busy-wait paradigm for parallel algorithms; applications of the basic paradigm to two problems are presented: building heaps, and executing parallel tree contraction (assuming a preparatory stage); the latter is known to be applicable to evaluating a family of general arithmetic expressions. For putting things in context, we also discuss our &ldquo;PRAM-on-chip&rdquo; vision (actually a small update to it), presented at SPAA98.
Designing PETS: a personal electronic teller of stories
Authors: Allison Druin, Jamie Montemayor, Jim Hendler, Britt McAlister, Angela Boltman, Eric Fiterman, Aurelie Plaisant, Alex Kruskal, Hanne Olsen, Isabella Revett, Thomas Plaisant Schwenn, Lauren Sumida, Rebecca Wagner
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

We have begun the development of a new robotic pet that can support children in the storytelling process. Children can build their own pet by snapping together the modular animal parts of the PETS robot. After their pet is built, children can tell stories using the My Pets software. These stories can then be acted out by their robotic pet. This video paper describes the motivation for this research and the design process of our intergenerational design team in building the first PETS prototypes. We will discuss our progress to date and our focus for the future.
An Integral with Three Parameters
Authors: George Boros, Victor H. Moll
Venue: SIAM Review (1998)

In this paper we give an exact expression for the integral \begin{eqnarray} I(a, b; r) = \int_{0}^{\infty} \left[ \frac{x^{2}}{x^{4} + 2a x^{2} + 1} \right]^{r} \cdot \frac{x^{2} + 1}{x^{b} + 1} \cdot \frac{dx}{x^{2}} \nonumber \end{eqnarray} in terms of Euler's beta function. Several classical integrals are deduced from it. The expression for $I(a,b;r)$ provides a method for unifying a large class of integrals.