ppxscal/embedding_network huggingface dataset:
An empirical evaluation of user interfaces for topic management of Web sites
Authors: Brian Amento, Will Hill, Loren Terveen, Deborah Hix, Peter Ju
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

Topic management is the task of gathering, evaluating, organizing, and sharing a set of web sites for a specific topic. Current web tools do not provide adequate support for this task. We created the TopicShop system to address this need. TopicShop includes (1) a webcrawler that discovers relevant web sites and builds site profiles, and (2) user interfaces for exploring and organizing sites. We conducted an empirical study comparing user performance with TopicShop vs. YahooTM. TopicShop subjects found over 80% more high-quality sites (where quality was determined by independent expert judgements) while browsing only 8 1% as many sites and completing their task in 89% of the time. The site profile data that TopicShop provides - in particular, the number of pages on a site and the number of other sites that link to it - was the key to these results, as users exploited it to identify the most promising sites quickly and easily.
ML(k)BiCGSTAB: A BiCGSTAB Variant Based on Multiple Lanczos Starting Vectors
Authors: Man-Chung Yeung, Tony F. Chan
Venue: SIAM Journal on Scientific Computing (1999)

We present a variant of the popular BiCGSTAB method for solving nonsymmetric linear systems. The method, which we denote by ML(k)BiCGSTAB, is derived from a variant of the BiCG method based on a Lanczos process using multiple (k > 1) starting left Lanczos vectors. Compared with the original BiCGSTAB method, our new method produces a residual polynomial which is of lower degree after the same number of steps, but which also requires fewer matrix-vector products to generate, on average requiring only 1+1/k matvecs per step. Empirically, it also seems to be more stable and more quickly convergent. The new method can be implemented as a k-term recurrence and can be viewed as a bridge connecting the Arnoldi-based FOM/GMRES methods and the Lanczos-based BiCGSTAB methods.
Kinetical-Consistent Algorithms for Simulation of Reactive Flows
Authors: Ludwig W. Dorodnicyn
Venue: SIAM Journal on Scientific Computing (1999)

For computation of chemically reacting flows, algorithms are proposed based on appoximations of the Boltzmann equations for gas mixtures. Finite-difference gas-dynamics schemes are constructed and applied to simulate viscous supersonic flows around two-dimensional bodies. An efficient procedure has been developed, permitting one to calculate the influence of chemical reactions on the flow.
XML-based information mediation with MIX
Authors: Chaitan Baru, Amarnath Gupta, Bertram Ludäscher, Richard Marciano, Yannis Papakonstantinou, Pavel Velikhov, Vincent Chu
Venue: ACM SIGMOD Record (1999)

The MIX mediator system, MIXm, is developed as part of the MIX Project at the San Diego Supercomputer Center, and the University of California, San Diego.1 MIXm uses XML as the common model for data exchange. Mediator views are expressed in XMAS (XML Matching And Structuring Language), a declarative XML query language. To facilitate user-friendly query formulation and for optimization purposes, MIXm employs XML DTDs as a structural description (in effect, a &ldquo;schema&rdquo;) of the exchanged data. The novel features of the system include: Data exchange and integration solely relies on XML, i.e., instance and schema information is represented by XML documents and XML DTDs, respectively. XML queries are denoted in XMAS, which builds upon ideas of languages like XML-QL, MSL, Yat, and UnQL. Additionally, XMAS features powerful grouping and order constructs for generating new integrated XML &ldquo;objects&rdquo; from existing ones. The graphical user interface BBQ (Blended Browsing and Querying) is driven by the mediator view DTD and integrates browsing and querying of XML data. Complex queries can be constructed in an intuitive way, resembling QBE. Due to the nested nature of XML data and DTDs, BBQ provides graphical means to specify the nesting and grouping of query results. Query evaluation can be demand-driven, i.e., by the user's navigation into the mediated view.
Design and analysis of low-power access protocols for wireless and mobile ATM networks
Authors: Krishna M. Sivalingam, Jyh-Cheng Chen, Prathima Agrawal, Mani B. Srivastava
Venue: Wireless Networks (2000)

This paper describes the design and analysis of a low&dash;power medium access control &lpar;MAC&rpar; protocol for wireless/mobile ATM networks. The protocol &ndash; denoted EC&dash;MAC &lpar;energy conserving medium access control&rpar; &ndash; is designed to support different traffic types with quality&dash;of&dash;service &lpar;QoS&rpar; provisions. The network is based on the infrastructure model where a base station &lpar;BS&rpar; serves all the mobiles currently in its cell. A reservation&dash;based approach is proposed, with appropriate scheduling of the requests from the mobiles. This strategy is utilized to accomplish the dual goals of reduced energy consumption and quality of service provision over wireless links. A priority round robin with dynamic reservation update and error compensation scheduling algorithm is used to schedule the transmission requests of the mobiles. Discrete&dash;event simulation has been used to study the performance of the protocol. A comparison of energy consumption of the EC&dash;MAC to a number of other protocols is provided. This comparison indicates the EC&dash;MAC has, in general, better energy consumption characteristics. Performance analysis of the proposed protocol with respect to different quality&dash;of&dash;service parameters using video, audio and data traffic models is provided.
The Chebyshev Polynomials of a Matrix
Authors: Kim-Chuan Toh, Lloyd N. Trefethen
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

A Chebyshev polynomial of a square matrix A is a monic polynomial p of specified degree that minimizes |p (A)|2. The study of such polynomials is motivated by the analysis of Krylov subspace iterations in numerical linear algebra. An algorithm is presented for computing these polynomials based on reduction to a semidefinite program which is then solved by a primal-dual interior point method. Examples of Chebyshev polynomials of matrices are presented, and it is noted that if A is far from normal, the lemniscates of these polynomials tend to approximate pseudospectra of A.
Answering complex SQL queries using automatic summary tables
Authors: Markos Zaharioudakis, Roberta Cochrane, George Lapis, Hamid Pirahesh, Monica Urata
Venue: ACM SIGMOD Record (2000)

We investigate the problem of using materialized views to answer SQL queries. We focus on modern decision-support queries, which involve joins, arithmetic operations and other (possibly user-defined) functions, aggregation (often along multiple dimensions), and nested subqueries. Given the complexity of such queries, the vast amounts of data upon which they operate, and the requirement for interactive response times, the use of materialized views (MVs) of similar complexity is often mandatory for acceptable performance. We present a novel algorithm that is able to rewrite a user query so that it will access one or more of the available MVs instead of the base tables. The algorithm extends prior work by addressing the new sources of complexity mentioned above, that is, complex expressions, multidimensional aggregation, and nested subqueries. It does so by relying on a graphical representation of queries and a bottom-up, pair-wise matching of nodes from the query and MV graphs. This approach offers great modularity and extensibility, allowing for the rewriting of a large class of queries.
Design and Analysis of Robust Binary Filters in the Context of a Prior Distribution for the States of Nature
Authors: Artyom M. Grigoryan, Edward R. Dougherty
Venue: Journal of Mathematical Imaging and Vision (1999)

An optimal binary-image filter estimates an ideal random set by means of an observed random set. A fundamental and practically important question regards the robustness of a designed filter: to what extent does performance degrade when the filter is applied to a different model than the one for which it has been designed? By parameterizing the ideal and observation random sets, one can analyze the robustness of filter design relative to parameter states. Based on a prior distribution for the states, a robustness mesure is defined for each state in terms of how well its optimal filter performs on models for different states. Not only is filter performance on other states taken into account, but so too is the contribution of other states in terms of their mass relative to the prior state distribution. This paper characterizes maximally robust states, derives performance bounds, treats mean robustness (as opposed to robustness by state), introduces a global filter that is applied across all states, particularizes the entire analysis to a sparse noise model for which there are analytic robustness expressions, and proposes a simplified model for determination of robust states from data. Sufficient conditions are given under which the global filter is uniformly more robust than all state-specific optimal filters.
Pre-electing a Leader in Distributed Networks
Authors: Tai Woo Kim, Tai Yun Kim
Venue: International Journal of Network Management (1996)

In this article the leader election algorithm based on the performance and operation rate of nodes and links is proposed.
A Circuit Architecture for Analog On-Chip Back Propagation Learning with Local Learning Rate Adaptation
Authors: G. M. Bo, D. D. Caviglia, H. Chiblè, M. Valle
Venue: Analog Integrated Circuits and Signal Processing (1999)

In this paper we present the analog CMOS architecture of a Multi Layer Perceptron network with on-chip stochastic Back Propagation learning. The learning algorithm is based on a local learning rate adaptation technique which makes the on-chip implementation more efficient (i.e. fast convergence speed) with respect to similar architectures presented in the literature. Circuit simulation results on the XOR learning problem validate the network behavior.
Designing courseware on algorithms for active learning with virtual board games
Authors: Nils Faltin
Venue: ACM SIGCSE Bulletin (1999)

We present a method for designing courseware on algorithms for active learning with virtual board games. Our goal is to build algorithm courseware that integrates explanation with animation and makes the student an active participant. We give hints for structuring the material into sections and mixing presentation with exercises. We present our ideas for a new form of visual interactive exercise and a cardboard game prototype with which we tested our ideas.
A Motivational Example for the Numerical Solution of the Algebraic Eigenvalue Problem
Authors: Stephen M. Alessandrini
Venue: SIAM Review (1998)

This paper presents an example of an algebraic eigenvalue problem which can be used to motivate the study of numerical techniques for solving such problems. The problem consists of finding the axis and angle of rotation from a $3\times3$ rotation matrix and is referred to as the axis-angle problem. The problem is used to demonstrate the inverse power method for finding eigenvectors. The axis-angle problem is developed and numerical results are given.
Mechanizing UNITY in Isabelle
Authors: Lawrence C. Paulson
Venue: ACM Transactions on Computational Logic (TOCL) (2000)

UNITY is an abstract formalism for proving properties of concurrent systems, which typically are expressed using guarded assignments [Chandy and Misra 1988]. UNITY has been mechanized in higher-order logic using Isabelle, a proof assistant. Safety and progress primitives, their weak forms (for the substitution axiom), and the program composition operator (union) have been formalized. To give a feel for the concrete syntax, this article presents a few extracts from the Isabelle definitions and proofs. It discusses a small example, two-process mutual exclusion. A mechanical theory of unions of programs supports a degree of compositional reasoning. Original work on extending program states is presented and then illustrated through a simple example involving an array of processes.
Performance evaluation of two operating systems
Authors: Humayun Khalid
Venue: ACM SIGARCH Computer Architecture News (1999)

This report compares the performance of two radically different versions of MacOS trade; operating system. In particular, we are interested in the study that focuses primarily on the emulation code related aspect of the performance of two version of the aforementioned operating system. ALPS (Application Level Performance Measurement Suite) benchmarks [1] were used as test cases due to the fact that they contains scenarios which stresses the operating system (OS) related activities.
A low-power clock and data recovery circuit for 2.5 Gb/s SDH receivers
Authors: Andrea Pallotta, Francesco Centurelli, Alessandro Trifiletti
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

A low power monolithic Clock and Data Recovery IC for 2.5 Gb/s SDH STM-16 systems has been designed and fabricated using Maxim GST-2 27 GHz-fT Silicon bipolar technology. The circuit performs the following functions: signal amplification and limitation, clock recovery and decision; a single 3.3 V supply voltage is required, and power consumption results below 350 mW. This IC and a previously presented transimpedance amplifier so allows composing a chip set for the receiver with a total power dissipation below 0.5 W. Preliminary measurements under a 223-1 PRBS data stream have shown an input sensitivity below 20 mVpp and a rms jitter of 10 ps.
A Scalable Substructuring Method by Lagrange Multipliers for Plate Bending Problems
Authors: Jan Mandel, Radek Tezaur, Charbel Farhat
Venue: SIAM Journal on Numerical Analysis (1999)

We present a new Lagrange multiplier-based domain decomposition method for solving iteratively systems of equations arising from the finite element discretization of plate bending problems. The proposed method is essentially an extension of the finite element tearing and interconnecting substructuring algorithm to the biharmonic equation. The main idea is to enforce continuity of the transversal displacement field at the subdomain crosspoints throughout the preconditioned conjugate gradient iterations. The resulting method is proved to have a condition number that does not grow with the number of subdomains but rather grows at most polylogarithmically with the number of elements per subdomain. These optimal properties hold for numerous plate bending elements that are used in practice including the Hsieh--Clough--Tocher element, the discrete Kirchhoff triangle, and a class of nonlocking elements for the Reissner--Mindlin plate models. Computational experiments are reported and shown to confirm the theoretical optimal convergence properties of the new domain decomposition method. Computational efficiency is also demonstrated with the numerical solution in 45 iterations and 105 seconds on a 64-processor IBM SP2 of a plate bending problem with almost one million degrees of freedom.
Routing in wireless/mobile ad-hoc networks via dynamic group construction
Authors: Yu-Liang Chang, Ching-Chi Hsu
Venue: Mobile Networks and Applications (2000)

An ad-hoc network is temporarily formed by a group of mobile hosts communicating over wireless channels without any fixed network interaction and centralized administration. When a mobile host communicates with other mobile hosts in an ad-hoc network, the routes are established via the intermediate mobile hosts as forwarding nodes. Under such a network environment an adaptive approach for routing management will be proposed in this paper. In this approach, at first the network infrastructure is constructed by several communication groups, which are called routing groups. A routing group communicates with other routing groups via the boundary mobile hosts as forwarding nodes. In a routing group the mobile hosts are divided, by means of the dominating values, into two groups &mdash; one positive cluster and several non-positive clusters. The nodes in the positive cluster maintain the topology information of the routing group. Under such a construction environment, intra-group routing performs unicasting and gets multiple paths, while inter-group routing performs on group level by propagating the route requests to the boundary clusters, which are called bridge clusters. This routing scheme massively reduces the message complexity that is especially important for system performance under such a resource constraint environment. As far as the dynamic topology characteristics of ad-hoc networks are concerned, this approach also provides a more efficient infrastructure update. Finally, simulation results show that the routing via dynamic group construction outperforms the previous works in message complexity and infrastructure update efficiency.
Students seen flocking in programming assignments
Authors: Tony Greening
Venue: ACM SIGCSE Bulletin (2000)

Programming assignments are typically constructed with great precision, in order to ensure that students traverse the important content areas in the unit. This paper makes a case for an "ill-defined", large programming task by presenting experiences with an assignment based on flocking behavior. Providing students meet the criteria that their artificial life forms clearly exhibit flocking behavior, they become responsible for defining the exact nature of the task. The success of this approach is partly measured by the ability of novice programmers who fully engage with the course material to produce spectacular results. The paper includes a discussion of the philosophical requirements for adopting such an approach within a programming unit.
Promoting computer software intellectual property right in Computer Science Education
Authors: Lan Yang, Zhiqiang Ding
Venue: ACM SIGCSE Bulletin (1999)

Computer software intellectual property right (IPR) protection has become an important issue of universal concern. This paper, based on a survey conducted in five Chinese universities reveals the importance of teaching the subject of computer software IPR to computer science students. The paper discusses the development of educational material that highlights the technical, cultural, legal and regulatory, and business factors related to computer software IPR. It also proposes an educational program for enhancing IPR protection, which can be incorporated into the undergraduate and graduate curricula of computer science.
Static single assignment form for machine code
Authors: Allen Leung, Lal George
Venue: ACM SIGPLAN Notices (1999)

Static Single Assignment (SSA) is an effective intermediate representation in optimizing compilers. However, traditional SSA form and optimizations are not applicable to programs represented as native machine instructions because the use of dedicated registers imposed by calling conventions, the runtime system, and target architecture must be made explicit. We present a simple scheme for converting between programs in machine code and in SSA, such that references to dedicated physical registers in machine code are preserved. Our scheme ignores all output- and anti-dependences imposed by physical registers while a program is in SSA form, but inserts compensation code during machine code reconstruction if any naming requirements have been violated. By resolving all mismatches between the two representations in separate phases, we are able to utilize existing SSA algorithms unaltered to perform machine code optimizations.
Cycle time and slack optimization for VLSI-chips
Authors: C. Albrecht, B. Korte, J. Schietke, J. Vygen
Venue: Proceedings of the 1999 IEEE/ACM international conference on Computer-aided design (1999)

We consider the problem of finding an optimal clock schedule, i.e. optimal arrival times for clock signals at latches of a VLSI chip. We describe a general model which includes all previously considered models. Then we show how to optimize the cycle time and optimally balance slacks on data paths and on clocktree paths.The problem of finding a clock schedule with the optimum cycle time was solved before, either by linear programming or by binary search, using a test for negative circuits in a digraph as a subroutine. We show for the first time that a direct combinatorial algorithm solves this problem optimally. Incidentally, this yields a new efficient method for timing analysis with transparent latches.Moreover, we extend this algorithm to the slack balancing problem: To make the chip less sensitive to routing detours, process variations and manufacturing skew it is desirable to have as few critical paths as possible. We show how to find the clock schedule with minimum number of critical paths (optimum slack distribution) in a well-defined sense. Rather than fixed clock arrival times we show how to obtain as large as possible intervals for the clock arrival times. This can be considered as slack on clocktree paths. Indeed, we can find the global optimum of simultaneous optimization of slacks on all data paths and clocktree paths.All the above is done by very efficient network optimization algorithms, based on parametric shortest paths. Our computational results with recent IBM processor chips show that the number of critical paths decreases dramatically, in addition to a considerable improvement of the cycle time. The running times are reasonable even for the largest designs.
NETMAN: the design of a collaborative wearable computer system
Authors: Gerd Kortuem, Martin Bauer, Zary Segall
Venue: Mobile Networks and Applications (1999)

This paper presents a wearable groupware system designed to enhance the communication and cooperation of highly mobile network technicians. It provides technicians in the field with the capabilities for real-time audio-conferencing, transmission of video images back to the office, and context-sensitive access to a shared notebook. An infrared location-tracking device allows for the automatic retrieval of notebook entries depending on the user's current location.
Repetitive Testing Strategies When the Testing Process is Imperfect
Authors: Jie Ding, Betsy S. Greenberg, Hirofumi Matsuo
Venue: Management Science (1998)

This paper considers the problem of test design and implementation when testing is imperfect. Items that are classified as conforming may be nonconforming, resulting in a poor outgoing quality level. Items that are classified as nonconforming may be conforming, resulting in excessive scrapping of conforming items. The failed items are commonly retested to reduce the scrapping problem. Alternatively, the accepted items may be retested to improve outgoing quality. In this paper, we examine the question of whether it is better to repetitively test rejected items, or to repetitively test accepted items. We also examine the relationship between the two testing policies, testing equipment accuracy and capacity, incoming quality, and outgoing quality requirements.