ppxscal/embedding_network huggingface dataset:
Eddies: continuously adaptive query processing
Authors: Ron Avnur, Joseph M. Hellerstein
Venue: ACM SIGMOD Record (2000)

In large federated and shared-nothing databases, resources can exhibit widely fluctuating characteristics. Assumptions made at the time a query is submitted will rarely hold throughout the duration of query processing. As a result, traditional static query optimization and execution techniques are ineffective in these environments. In this paper we introduce a query processing mechanism called an eddy, which continuously reorders operators in a query plan as it runs. We characterize the moments of symmetry during which pipelined joins can be easily reordered, and the synchronization barriers that require inputs from different sources to be coordinated. By combining eddies with appropriate join algorithms, we merge the optimization and execution phases of query processing, allowing each tuple to have a flexible ordering of the query operators. This flexibility is controlled by a combination of fluid dynamics and a simple learning algorithm. Our initial implementation demonstrates promising results, with eddies performing nearly as well as a static optimizer/executor in static scenarios, and providing dramatic improvements in dynamic execution environments.
Voice over IP
Authors: Uyless Black
Venue:  (1999)

Uyless Black has written the essential guide for telecommunications professionals who must understand voice-over-IP (VoIP)-or deploy it. Clearheaded and free of hype, Voice Over IP carefully evaluates both VoIP's challenges and its compelling advantages, and then reviews each technical standard and critical issue associated with successful deployment. Black describes today's best approaches for managing performance in both private and public IP networks, compares VoIP with packet voice alternatives such as Voice over Frame Relay (VoFR) and Voice over ATM (VoATM), and more. You'll also find convenient references to telephony signaling, ISDN and SS7, and V.90 modems. Every telecommunications professional will be impacted by the VoIP revolution. Whether you're evaluating or deploying VoIP, Voice Over IP places a world-class telecom consultant at your side, delivering all the objective information and insight you need to succeed.
A Scan-BIST Structure to Test Delay Faults in Sequential Circuits
Authors: P. Girard, C. Landrault, V. Moreda, S. Pravossoudovitch, A. Virazel
Venue: Journal of Electronic Testing: Theory and Applications (1999)

Delay testing that requires the application of consecutive two-pattern tests is not an easy task in a scan-based environment. This paper proposes a novel approach to the delay fault testing problem in scan-based sequential circuits. This solution is based on the combination of a BIST structure with a scan-based design to apply delay test pairs to the circuit under test.
Evaluation of predicated array data-flow analysis for automatic parallelization
Authors: Sungdo Moon, Mary W. Hall
Venue: ACM SIGPLAN Notices (1999)

This paper presents an evaluation of a new analysis for parallelizing compilers called predicated array data-flow analysis. This analysis extends array data-flow analysis for parallelization and privatization to associate predicates with data-flow values. These predicates can be used to derive conditions under which dependences can be eliminated or privatization is possible. These conditions can be used both to enhance compile-time analysis and to introduce run-time tests that guard safe execution of a parallelized version of a computation.As compared to previous work that combines predicates with array data-flow analysis, our approach is distinguished by two features: (1) it derives low-cost, run-time parallelization tests; and, (2) it incorporates predicate embedding and predicate extraction, which translate between the domain of predicates and data-flow values to derive more precise analysis results. We present extensive experimental results across three benchmark suites and one additional program, demonstrating that predicated array data-flow analysis parallelizes more than 40% of the remaining inherently parallel loops left unparallelized by the SUIF compiler and that it yields improved speedups for 5 programs.
Internet traffic warehouse
Authors: Chung-Min Chen, Munir Cochinwala, Claudio Petrone, Marc Pucci, Sunil Samtani, Patrizia Santa
Venue: ACM SIGMOD Record (2000)

We report on a network traffic warehousing project at Telcordia. The warehouse supports a variety of applications that require access to Internet traffic data. The applications include Service Level Agreement (SLA), web traffic analysis, network capacity engineering and planning, and billing. We describe the design of the warehouse and the issues encountered in building the warehouse.
Feedback Stabilization of Bilinear Control Systems
Authors: Hualin Wang
Venue: SIAM Journal on Control and Optimization (1998)

In this paper, we study the region in which a bilinear control system is feedback stabilizable. In particular, we find a necessary and sufficient condition for feedback stabilization in terms of the Lyapunov spectrum.
A Multigrid Algorithm for the Mortar Finite Element Method
Authors: Dietrich Braess, Wolfgang Dahmen, Christian Wieners
Venue: SIAM Journal on Numerical Analysis (1999)

The objective of this paper is to develop and analyze a multigrid algorithm for the system of equations arising from the mortar finite element discretization of second order elliptic boundary value problems. In order to establish the inf-sup condition for the saddle point formulation and to motivate the subsequent treatment of the discretizations, we first revisit briefly the theoretical concept of the mortar finite element method. Employing suitable mesh-dependent norms we verify the validity of the Ladyzhenskaya--Babuska--Brezzi (LBB) condition for the resulting mixed method and prove an L2 error estimate. This is the key for establishing a suitable approximation property for our multigrid convergence proof via a duality argument. In fact, we are able to verify optimal multigrid efficiency based on a smoother which is applied to the whole coupled system of equations. We conclude with several numerical tests of the proposed scheme which confirm the theoretical results and show the efficiency and the robustness of the method even in situations not covered by the theory.
A General Additive Data Perturbation Method for Database Security
Authors: Krishnamurty Muralidhar, Rahul Parsa, Rathindra Sarathy
Venue: Management Science (1999)

The security of organizational databases has received considerable attention in the literature in recent years. This can be attributed to a simultaneous increase in the amount of data being stored in databases, the analysis of such data, and the desire to protect confidential data. Data perturbation methods are often used to protect confidential, numerical data from unauthorized queries while providing maximum access and accurate information to legitimate queries. To provide accurate information, it is desirable that perturbation does not result in a change in relationships between attributes. In the presence of nonconfidential attributes, existing methods will result in such a change. This study describes a new method (General Additive Data Perturbation) that does not change relationships between attributes. All existing methods of additive data perturbation are shown to be special cases of this method. When the database has a multivariate normal distribution, the new method provides maximum security and minimum bias. For nonnormal databases, the new method provides better security and bias performance than the multiplicative data perturbation method.
A study on channel allocation for data dissemination in mobile computing environments
Authors: Wang-Chien Lee, Qinglong Hu, Dik Lun Lee
Venue: Mobile Networks and Applications (1999)

This paper studies channel allocation methods for data dissemination through broadcast and on-demand channels. Analytical models and cost formulae for exclusive broadcast channels and exclusive on-demand channels are provided. Based on the models, we further derive cost models for dynamic channel allocation methods and propose a channel adaptation algorithm for optimizing system performance. The channel adaptation algorithm can be executed in O(n) time, where n is the number of data items in the database. Performance evaluation shows that the channel allocation algorithm produces optimal channel allocation which significantly improves the system performance under various parameter settings.
Aclips: a Capacity and Lead Time Integrated Procedure for Scheduling
Authors: Marc R. Lambrecht, Philip L. Ivens, Nico J. Vandaele
Venue: Management Science (1998)

We propose a general hierarchical procedure to address real-life job shop scheduling problems. The shop typically produces a variety of products, each with its own arrival stream, its ow route through the shop and a given customer due date. The procedure first determines the manufacturing lot sizes for each product. The objective is to minimize the expected lead time, and therefore we model the production environment as a queueing network. Given these lead times, release dates are set dynamically. This in turn creates a time window for every manufacturing order in which the various operations have to be sequenced. The sequencing logic is based on an Extended Shifting Bottleneck Procedure. These three major decisions are next incorporated into a four-phase, hierarchical, operational implementation scheme. A small numerical example is used to illustrate the methodology. The final objective however is to develop a procedure that is useful for large, real-life shops. We therefore report on a real-life application.
Computing Equilibria in Stochastic Finance Economies
Authors: Felix Kubler, Karl Schmedders
Venue: Computational Economics (2000)

We describe a homotopy algorithm for the computation of equilibria in Stochastic Finance Economies. The algorithm solves a nonlinear system of equations consisting of the first-order conditions of the agents' utility maximization problems and market-clearing conditions. Moreover, we discuss the use of a straightforward homotopy approach for local comparative statics. Using our methods we evaluate price, volatility, and welfare effects of options in incomplete asset markets.
Pseudospectral Chebyshev Optimal Control of Constrained Nonlinear Dynamical Systems
Authors: Gamal N. Elnagar, Mohammad A. Kazemi
Venue: Computational Optimization and Applications (1998)

A pseudospectral method for generating optimal trajectories of linear and nonlinear constrained dynamic systems is proposed. The method consists of representing the solution of the optimal control problem by an mth degree interpolating polynomial, using Chebyshev nodes, and then discretizing the problem using a cell-averaging technique. The optimal control problem is thereby transformed into an algebraic nonlinear programming problem. Due to its dynamic nature, the proposed method avoids many of the numerical difficulties typically encountered in solving standard optimal control problems. Furthermore, for discontinuous optimal control problems, we develop and implement a Chebyshev smoothing procedure which extracts the piecewise smooth solution from the oscillatory solution near the points of discontinuities. Numerical examples are provided, which confirm the convergence of the proposed method. Moreover, a comparison is made with optimal solutions obtained by closed-form analysis and/or other numerical methods in the literature.
SEIS++: a pattern language for seismic tools construction and integration
Authors: Li Yingjun, Lu Jian
Venue: ACM SIGPLAN Notices (1999)

Predominant industrial practice has evolved from general-purpose class libraries to domain-specific frameworks" and design patterns. Both of them are a means to achieve large-scale reuse by capturing successful software development strategies within a particular context. Design patterns focus on reuse of recurring architectural design themes and mainly consist of predefined design structures that can be used as building blocks to compose the architecture of software system. Together the patterns in a specific domain form a pattern language, which can be used to approach a certain class of problems in the application domain. In this paper, we propose a pattern language SEIS++, a set of design patterns, for seismic tool construction and integration in oil and gas exploration domain. The language uses Tools and Materials as the new design conception to guide domain-specific application development, and to enhance software architecture reusability.
GFSR pseudorandom number generation using APL
Authors: Charles Winton
Venue: ACM SIGAPL APL Quote Quad (1998)

This paper demonstrates the effectiveness of APL for implementing the generalized feedback shift register (GFSR) approach to producing a random number stream. Various approaches to generating streams of pseudorandom numbers computationally have been devised, dating at least as far back as Norbert Wiener. These are normally discussed in the context of a course in modeling and simulation, since there may be practical implications to consider when building simulation models in APL or any other high level language. This is particularly the case for those circumstances when a (pseudo) random number sequence needs to be repeated, or when multiple streams are needed. In such cases a pseudorandom number generator other than that supplied in the programming language command set needs to be implemented. The linear congruential method for pseudorandom number generation is still commonly used, and is easily implemented in APL or any other high level language; however, it is known to have undesirable n-space uniformity characteristics. Moreover, the period length of its random number stream is limited by the underlying machine's word size. This is a serious issue, since at present day computer speeds, a simulation run could exhaust such a random number stream in a few hours. Very long period (VLP) pseudorandom number generators remedy this deficiency.One class of these, generalized feedback shift register (GFSR) pseudorandom number generators, is based on algebraic manipulation of irreducible trinomials of high order. The manner in which this is accomplished particularly lends itself to elegant APL implementation.
A Test for Strong Hysteresis
Authors: Laura Piscitelli, Rod Cross, Michael Grinfeld, Harbir Lamba
Venue: Computational Economics (2000)

The mathematical definition of systems with hysteresis, that is nonlinear input-output systems with memory, is different from the definition usually applied to economic systems. Economic theory and modelling practice have almost always specified simple dynamic systems with regular leads and lags in their responses, corresponding to input-output systems with unit or zero (or at least stable) roots. These models cannot capture the `selective memory' feature of hysteretic behaviour, that is, the influence only of certain past events (typically, non-dominated sequences of previous peaks and troughs). There is therefore a difficulty in testing for and validating economic models containing hysteretic behaviour; appropriate empirical tests have not been developed. In particular, the usual unit vs. zero (or stable) root tests used in econometric analysis are unable to detect hysteretic behaviour or to distinguish it from more conventional economic behaviour. The purpose of this paper is to propose a new way of testing for hysteresis, by drawing on some ideas in the mathematical/control theory literature and adapting them to fit into the economic frameworks with elements of hysteresis.
Robust Schur Stability of Polynomials with Polynomial ParameterDependency
Authors: Jürgen Garloff, Birgit Graf
Venue: Multidimensional Systems and Signal Processing (1999)

The paper considers the robust Schur stability verification of polynomials with coefficients depending polynomially on parameters varying in given intervals. A new algorithm is presented which relies on the expansion of a multivariate polynomial into Bernstein polynomials and is based on the decomposition of the family of polynomials into its symmetric and antisymmetric parts. It is shown how the inspection of both polynomial families on the upper half of the unit circle can be reduced to the analysis of two related polynomial families on the real interval [-1,1]. Then the Bernstein expansion can be applied in order to check whether both polynomial families have a zero in this interval in common.
Energy-efficient 32 &times; 32-bit multiplier in tunable near-zero threshold CMOS
Authors: Vjekoslav Svilan, Masataka Matsui, James B. Burr
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

An 80,000 transistor, low swing, 32~x~32-bit multiplier was fabricated in a standard 0.35&mgr;m,Vth=0.5 V CMOS process and in a 0.35&mgr;m, back-bias tunable, near-zero Vth process. While standard CMOS atVdd=3.3 V runs at 136 MHz, the same performance can be achieved in the low- Vth version at Vdd=1.3 V, resulting in more than 5 times lower power. Similar power reductions are obtained for frequencies down to 10 MHz. In addition, the low-Vth version is able to run at 188 MHz, which is 38% faster than standard CMOS.
Prioritizing Information for the Discovery of Phenomena
Authors: Paul Helman, Rebecca Gore
Venue: Journal of Intelligent Information Systems (1998)

We consider the problem of prioritizing a collection of discrete pieces of information, or transactions. The goal is to rank the transactions in such a way that the user can best pursue a subset of the transactions in hopes of discovering those which were generated by an interesting source. The problem is shown to differ from traditional classification in several fundamental ways. Ranking algorithms are divided into classes, depending on the amount of information they may utilize. We demonstrate that while ranking by the least constrained algorithm class is consistent with classification, such is not the case for a more constrained class of algorithms. We demonstrate also that while optimal ranking by the former class is &ldquo;easy&rdquo;, optimal ranking by the latter class is NP-hard. Finally, we present detectors which solve optimally restricted versions of the ranking problem, including symmetric anomaly detection.
Characterization of Floating Gate Defects in Analog Cells
Authors: Anna M. Brosa, Joan Figueras
Venue: Journal of Electronic Testing: Theory and Applications (1999)

A unified approach to tackle the characterization of the floating gate defect in analog and mixed-signal circuits is introduced. An electrical level model of the defective circuit is proposed extending previous models used effectively in the digital domain. The poly-bulk, poly-well, poly-power rail and metal-poly capacitances are significant parameters in determining the behavior of the floating gate transistor. The model is used to analyze the feasibility of testing a simple analog cell with the floating gate defects through the observation of the quiescent current consumption and the dynamic behavior.
A collaborative strategy for developing shared Java teaching resources to support first year programming
Authors: Ainslie Ellis, Dianne Hagan, Judy Sheard, Jason Lowder, Wendy Doube, Angela Carbone, John Robinson, Sylvia Tucker
Venue: Proceedings of the 4th annual SIGCSE/SIGCUE ITiCSE conference on Innovation and technology in computer science education (1999)

This paper discusses a strategy for developing shared teaching resources to support Java programming subjects taught using a variety of educational approaches (lectures and tutorials, problem-based learning, distance education) with differing computing focii (computer science, commercial computing, network computing).The strategy is a group process involving six distinct stages: selecting the topic areas considered integral to all subjects for which the resources will be used; defining the details and identifying areas / concepts of a topic; determining basic, intermediate and advanced levels of information; determining appropriate educational techniques that support the desired learning objectives for the concept; investigating existing resources and building new resources, both with and without the use of computer technology.
The context toolkit: aiding the development of context-enabled applications
Authors: Daniel Salber, Anind K. Dey, Gregory D. Abowd
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

Context-enabled applications are just emerging and promise richer interaction by taking environmental context into account. However, they are difficult to build due to their distributed nature and the use of unconventional sensors. The concepts of toolkits and widget libraries in graphical user interfaces has been tremendously successtil, allowing programmers to leverage off existing building blocks to build interactive systems more easily. We introduce the concept of context widgets that mediate between the environment and the application in the same way graphical widgets mediate between the user and the application. We illustrate the concept of context widgets with the beginnings of a widget library we have developed for sensing presence, identity and activity of people and things. We assess the success of our approach with two example context-enabled applications we have built and an existing application to which we have added context-sensing capabilities.
Parallel Speech Recognition
Authors: Steven Phillips, Anne Rogers
Venue: International Journal of Parallel Programming (1999)

Computer speech recognition has been very successful in limited domains and for isolated word recognition. However, widespread use of large-vocabulary continuous-speech recognizers is limited by the speed of current recognizers, which cannot reach acceptable error rates while running in real time. This paper shows how to harness shared memory multiprocessors, which are becoming increasingly common, to increase the speed significantly, and therefore the accuracy or vocabulary size, of a speech recognizer. To cover the necessary background, we begin with a tutorial on speech recognition. We then describe the parallelization of an existing high-quality speech recognizer, achieving a speedup of a factor of 3, 5, and 6 on 4-, 8-, and 12-processors respectively for the benchmark North American business news (NAB) recognition task.
Language translators: a reasoned synopsis
Authors: Luigi Benedicenti, Tullio Vernazza
Venue: ACM SIGAPP Applied Computing Review (1999)

The authors present a reasoned synopsis of the state of the art of compiler techniques. A classification scheme is employed that divides compilers according to two layers. The first layer is the input layer, dealing with the kind of language that the compiler will find. The second layer is the architectural layer, that will define the compiler's internals and the method employed to produce the output.
Learning to Parse Natural Language with Maximum Entropy Models
Authors: Adwait Ratnaparkhi
Venue: Machine Learning (1999)

This paper presents a machine learning system for parsing natural language that learns from manually parsed example sentences, and parses unseen data at state-of-the-art accuracies. Its machine learning technology, based on the maximum entropy framework, is highly reusable and not specific to the parsing problem, while the linguistic hints that it uses to learn can be specified concisely. It therefore requires a minimal amount of human effort and linguistic knowledge for its construction. In practice, the running time of the parser on a test sentence is linear with respect to the sentence length. We also demonstrate that the parser can train from other domains without modification to the modeling framework or the linguistic hints it uses to learn. Furthermore, this paper shows that research into rescoring the top 20 parses returned by the parser might yield accuracies dramatically higher than the state-of-the-art.