ppxscal/embedding_network huggingface dataset:
A Decomposition Procedure for the Analysis of a Closed Fork/Join Queueing System
Authors: Y. C. Liu, H. G. Perros
Venue: IEEE Transactions on Computers (1991)

An iterative approximation algorithm for analyzing a closed queueing system with a K-sibling fork/join queue is presented. The iterative procedure is based on a combination of nearly complete decomposability and the Gauss-Seidel method. The approximation procedure gives good results for the mean response time and the system throughput. The iterative procedure converges to the exact solution in the case of the closed 3-sibling fork/join queue.
ACM SIGGRAPH education committee activities for computer graphics educators
Authors: G. Scott Owen
Venue: ACM SIGGRAPH Computer Graphics (1991)

ACM SIGGRAPH supports computer graphics educators and students through the activities and projects of its education committee. These include curriculum studies, publication of informational materials and support of projects with educational value, plus many ACM SIGGRAPH conference-related activities. This paper discusses these activities and the associated resources that the education committee is making available for computer graphics educators.
Integrated systems based on behaviors
Authors: Rodney A. Brooks
Venue: ACM SIGART Bulletin (1991)

Behavior based systems require an orthogonal view of integration issues. In this paper we highlight those issues, discuss what is easy, what is hard, and where the research frontiers lie.
A Classification of Transaction Processing Systems
Authors: Avraham Leff, Calton Pu
Venue: Computer (1991)

The problems in building a transaction processing system are discussed, and it is shown that the difficulties are a function of specific attributes of the underlying database system. A model of a transaction processing system is presented, and five system dimensions important in classifying transaction processing systems-the process, machine, heterogeneity, data, and site components-are introduced. The specific problems posed by various combinations of system characteristics are analyzed. The evolution of transaction processing systems are described in terms of the framework.
Algorithm 693: a FORTRAN package for floating-point multiple-precision arithmetic
Authors: David M. Smith
Venue: ACM Transactions on Mathematical Software (TOMS) (1991)

FM is a collection of FORTRAN-77 routines which performs floating-point multiple-precision arithmetic and elementary functions. Results are almost always correctly rounded, and due to improved algorithms used for elementary functions, reasonable efficiency is obtained.
Authentication for Distributed Systems
Authors: Thomas Y. C. Woo, Simon S. Lam
Venue: Computer (1992)

A number of protocols used to authenticate users, hosts and processes are described. The three main types of authentication in a distributed computing system-message content authentication, message origin authentication, and general identity authentication-are explained. Authentication exchanges are identified, and paradigms of authentication protocols are presented. Authentication protocol failures are addressed, and an authentication framework is provided. As case studies, two authentication services, Kerberos and SPX, are examined.
Knowledge-based systems for idea processing
Authors: Lawrence F. Young
Venue: ACM SIGMIS Database (1991)

Knowledge-based systems methods have been seen as means of enhancing the nature of support provided by Decision Support Systems. This paper examines how they can be similarly used to provide user guidance and to represent forms of knowledge that are relevant to the newer type of qualitative support systems called Idea Processing. Basic concepts of Idea Processing and Knowledge-based systems are summarized. The paper identifies several modes of knowledge representation appropriate for particular functions of Idea Processing.
Delirium: an embedding coordination language
Authors: Steven Lucco, Oliver Sharp
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

Parallel programs consist of a group of sequentially executing sub-computations which cooperate to solve a problem. To exploit existing sequential code and available optimization tools, programmers usually choose to write these sub-computations in traditional imperative languages such as C and Fortran. A coordination language expresses data exchange and synchronization among such sub-computations. Current coordination languages support a variety of interaction models. Delirium introduces a new, more restrictive coordination model that provides the benefit of deterministic execution without requiring programmers to re-write large amounts of code. Current coordination languages are embedded; they work through the insertion of coordination primitives within a host language. Delirium is the first example of an embedding coordination language. A Delirium program is a compact representation of a framework for accomplishing a task in parallel.
Neural networks: a new dimension in expert systems applications
Authors: Mohammed H. A. Tafti
Venue: ACM SIGMIS Database (1992)

Despite significant advances in expert systems, efforts to build truly intelligent systems that approach reasoning and sensory ability of humans have not been rewarding. A new AI approach, neural networks, utilizes brain-like processing to emulate human learning. This approach will be the focus of commercial applications of AI in the 90s. This article will discuss major features of neural networks and address the impact of this approach on expert systems, as well as implications for research in this area.
Using spoken language to facilitate military transportation planning
Authors: Madeleine Bates, Dan Ellard, Pat Peterson, Varada Shaked
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

The DARPA SLS Program is developing a technology that has been justified, at least in part, by its potential relevance to military applications. In an effort to demonstrate the relevance of SLS technology to real-world military applications, BBN has undertaken the task of providing a spoken language interface to DART, a system for military logistical transportation planning.We discuss the transportation planning process, describe the real-world DART system, identify parts of the system where spoken language can facilitate planning, and describe BBN's work towards porting the HARC SLS system to the DART domain.
Representation quality in text classification: an introduction and experiment
Authors: David D. Lewis
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

The way in which text is represented has a strong impact on the performance of text classification (retrieval and categorization) systems. We discuss the operation of text classification systems, introduce a theoretical model of how text representation impacts their performance, and describe how the performance of text classification systems is evaluated. We then present the results of an experiment on improving text representation quality, as well as an analysis of the results and the directions they suggest for future research.
Ray tracing surfaces of revolution using a simplified strip tree method (abstract)
Authors: H. B. Bidasaria
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

In ray tracing a surface of revolution, the problem of finding the point of intersection of an arbitrary ray with the surface of revolution can be reduced to that of finding a point of intersection between two curves in a plane &mdash; the so called cut plane. In the cut plane, by using a local coordinate system (x&prime;=x2,z&prime;=z) instead of (x, z) where z is along the direction parallel to the axis of the surface of revolution, and then further translating the origin of the coordinate system along the x&prime; axis (depending upon the ray), the curve(s) of intersection of the surface of revolution with the cut plane are expressed exactly by the square radial curve defining the surface of revolution itself. We need to find the point(s) of intersection between this square radial curve and a transformed quadratic form of the ray in the cut plane. We represent the square radial curve of the surface of rotation by a variation of the usual strip_tree such that the direction of the sides of the rectangles corresponding to different nodes are parallel to the axes of the local coordinate system, instead of being in arbitrary directions. The terminal nodes in the Strip_tree contain the segments of the square radial curve divided approximately equally lengthwise. The method works efficiently for all cases with a smooth radial curve or a piecewise smooth radial curve.
Dynamic queries for information exploration: an implementation and evaluation
Authors: Christopher Ahlberg, Christopher Williamson, Ben Shneiderman
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

We designed, implemented and evaluated a new concept for direct manipulation of databases, called dynamic queries, that allows users to formulate queries with graphical widgets, such as sliders. By providing a graphical visualization of the database and search results, users can find trends and exceptions easily. Eighteen undergraduate chemistry students performed statistically significantly faster using a dynamic queries interface compared to two interfaces both providing form fill-in as input method, one with graphical visualization output and one with all-textual output. The interfaces were used to explore the periodic table of elements and search on their properties.
Algorithms for subset testing and finding maximal sets
Authors: Daniel M. Yellin
Venue: Proceedings of the third annual ACM-SIAM symposium on Discrete algorithms (1992)

In this paper we consider two related problems: subset testing and finding maximal sets. First, consider a sequence of n operations, where each operation either creates a set, inserts (deletes) an element into (from) a set, queries whether a particular element is in a set, queries whether or not one set is a subset of another, or queries whether or not the intersection of two sets is empty. We show that for any integer k, one can implement subset and intersection testing in time O(n1-(1/k) log n) and all of the other operations in time O(n1/k log n)). It requires O(nk+1)/k) space. When k = 2, this yields a worst case time complexity of O(n1/2 log n) per operation, and uses O(n3/2) space. Second, consider a set of sets, where the total size of the input is O(n). We show that one can find those sets that are maximal (a set is maximal if it is not contained in any other set) in time O(mn), where m is the number of maximal sets.
A survey &ldquo;APL thinking&rdquo;
Authors: Murray Eisenberg, Howard A. Peelle
Venue: ACM SIGAPL APL Quote Quad (1990)

During the APL86 conference in Manchester, England, we conducted a questionnaire survey of some aspects of "APL Thinking." We feel that the findings are as useful now as then, so to provide feedback to the APL community, we summarize the results here.The purpose of the survey was to understand how people think while programming in APL. Our ultimate aim is to improve the learning, teaching, and dissemination of APL.Respondents were specifically asked to concentrate on the thinking processes involved in APL programming, rather than on applications, language design and enhancements, or environment and implementation issues. (See the sample form on page 8 for a facsimile of the questionnaire.)
Three new algorithms for multivariate polynomial GCD
Authors: Tateaki Sasaki, Masayuki Suzuki
Venue: Journal of Symbolic Computation (1992)

Three new algorithms for multivariate polynomial GCD (greatest common divisor) are given. The first is to calculate a Grobner basis with a certain term ordering. The second is to calculate the subresultant by treating the coefficients w.r.t. the main variable as truncated power series. The third is to calculate a PRS (polynomial remainder sequence) by treating the coefficients as truncated power series. The first algorithm is not important practically, but the second and third ones are efficient and seem to be useful practically. The third algorithm has been implemented naively and compared with the trial-division PRS algorithm and the EZGCD algorithm. Although it is too early to derive a definite conclusion, the PRS method with power series coefficients is very efficient for calculating low degree GCD of high degree non-sparse polynomials.
Summary of post-symposium evaluations from 1991 SIGCSE technical symposium on computer science education
Authors: Vicki L. Almstrum, David C. Platt
Venue: ACM SIGCSE Bulletin (1991)

The 1991 SIGCSE Technical Symposium was held March 7-8, 1991, in San Antonio, Texas. A post-symposium evaluation form was made available to all attendees, with the request that it be filled out to assist the '91 committee in evaluating the current symposium and to help future committees in planning their symposia. This article highlights the responses to the evaluation forms and includes excerpts from the chair report, the registration report, and the treasurer's report.
Integration of diverse recognition methodologies through reevaluation of N-best sentence hypotheses
Authors: M. Ostendorf, A. Kannan, S. Austin, O. Kimball, R. Schwartz, J. R. Rohlicek
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

This paper describes a general formalism for integrating two or more speech recognition technologies, which could be developed at different research sites using different recognition strategies. In this formalism, one system uses the N-best search strategy to generate a list of candidate sentences; the list is rescored by other systems; and the different scores are combined to optimize performance. Specifically, we report on combining the BU system based on stochastic segment models and the BBN system based on hidden Markov models. In addition to facilitating integration of different systems, the N-best approach results in a large reduction in computation for word recognition using the stochastic segment model.
Pseudorandom Rounding for Truncated Multipliers
Authors: N. Yoshida, E. Goto, S. Ichikawa
Venue: IEEE Transactions on Computers (1991)

An economical, unbiased, overflow-free rounding scheme for multiplication of multiple-precision floating-point numbers is proposed. The scheme, called pseudorandom rounding, saves multiplications of lower bits and makes use of statistical properties of bits around the least significant bit of products in order to compensate for truncated parts. The method is deterministic, and inputs are commutable. The validity of the rounding is verified by numerical simulation.
Lexical access with a statistically-derived phonetic network
Authors: Michael D. Riley, Andrej Ljolje
Venue: Proceedings of the workshop on Speech and Natural Language (1991)

A probabilistic approach to lexical access from a recognized phone sequence is presented. Lexical access is seen as finding the word sequence that maximizes the lexical likelihood of a sequence of phones and durations as <i>recognized</i> by a <i>phone recognizer</i>. This is theoretically correct for minimum error rate recognition within the model presented and is intuitively pleasing since it means that the "confusion matrix" of the phone recognizer will be learned and its regularities exploited. The lexical likelihoods are estimated from training data provided by the phone recognizer using statistical decision trees. Classification trees are used to estimate the phone realiziation distributions and regression trees are used to estimate the phone duration distributions. We find they can capture effectively allophonic variation, alternative pronunciation, word co-articulation and segmental durations. We describe a simpified, but efficient implementation of these models to lexical access in the DARPA resource management recognitiion task.
SKILL: A CAD system extension language
Authors: Timothy J. Barnes
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

SKILL is a programming language that supports both command entry and procedural customization in OpusTM Design FrameworkTM. After briefly considering some related work, we examine the requirements that motivate the provision of a programming language available to the user and describe some of the technical characteristics of the language design and implementation. Finally, we describe our experience with the language and outline future work. A number of programming examples are appended.
Parallel Computing Optimization in the Apollo Domain Network
Authors: M. Ferhan Pekergin
Venue: IEEE Transactions on Software Engineering (1992)

The performance of parallel computing in a network of Apollo workstations where the processes use the remote procedure call (RPC) mechanism for communication is addressed. The speedup in such systems cannot be accurately estimated without taking into account the relatively large communication overheads. Moreover, it decreases by increasing parallelism when the latter exceeds some certain limit. To estimate the speedup and determine the optimum degree of parallelism, the author characterizes the parallelization and the communication overheads in the system considered. Then, parallel applications are modeled and their execution times are expressed for the general case of nonidentical tasks and workstations. The general case study allows the structural constraints of the applications to be taken into account by permitting their partitioning into heterogeneous tasks. A simple expression of the optimum degree of parallelism is obtained for identical tasks where the inherent constraints are neglected. The fact that the theoretical maximum speedup is bounded by half of the optimum degree of parallelism shows the importance of this measure.
3-D Surface Description from Binocular Stereo
Authors: Steven D. Cochran, Gérard Medioni
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

A stereo vision system that attempts to achieve robustness with respect to scene characteristics, from textured outdoor scenes to environments composed of highly regular man-made objects is presented. It integrates area-based and feature-based primitives. The area-based processing provides a dense disparity map, and the feature-based processing provides an accurate location of discontinuities. An area-based cross correlation, an ordering constraint, and a weak surface smoothness assumption are used to produce an initial disparity map. This disparity map is only a blurred version of the true one because of the smoothing introduced by the cross correlation. The problem can be reduced by introducing edge information. The disparity map is smoothed and the unsupported points removed. This method gives an active role to edgels parallel to the epipolar lines, whereas they are discarded in most feature-based systems. Very good results have been obtained on complex scenes in different domains.
Annotating answers with their properties
Authors: Amihai Motro
Venue: ACM SIGMOD Record (1992)

When responding to queries, humans often volunteer additional information about their answers. Among other things, they may qualify the answer as to its reliability, and they may provide some abstract characterization of the answer. This paper describes a user interface to relational databases that similarly annotates its answers with their properties. The process assumes that various assertions about properties of the data have been stored in the database (meta-information). These assertions are then used to infer properties of each answer provided by the system (meta-answers). Meta-answers are offered to users along with each answer issued, and help them to assess the value and meaning of the information that they receive.
Load balanced deadlock-free deterministic routing of arbitrary networks
Authors: David J. Pritchard
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

This paper provides efficient algorithms to deadlock-free route arbitrary multiprocessor interconnection networks as follows: 1. An algorithm is derived for fixed directory routing on an arbitrary network topology such that messages will be routed via one of the shortest routes whilst maintaining an even distribution of traffic over the network (assuming that messages are generated and absorbed in an even manner, or two-phase random routing is used). 2. An algorithm is presented which will evenly map virtual links onto the routed network so that it will be deadlock-free using the minimum number of buffer classes per physical link, thus maximising the buffer size per virtual link.
Kernel Designs for Efficient Multiresolution Edge Detection and Orientation Estimation
Authors: R. Wilson, A. H. Bhalerao
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

Deals with the design of filter kernels having specified radial and angular frequency responses based on combined optimization and frequency sampling. This is used to generate small-radius, low-pass, and edge-detection kernels for multiresolution pyramids. The performance of the new kernels in estimating orientation is shown to be significantly better than that of other commonly used pyramid kernels.
Why a two pass front end?
Authors: Janice C. Shepherd
Venue: ACM SIGPLAN Notices (1991)

Compilers for some programming languages are traditionally considered to be best implemented with a front end (lexical analysis, semantic analysis and intermediate code generation phases) that makes only one pass over the source program. A FORTRAN compiler was converted from such a design to one that uses two passes for the benefit of obtaining a front end that is easier to understand and maintain. The details of which language features motivated this conversion are presented. Performance results are also presented that show there was only a 4% increase in compile time after the conversion.
Availability of f2c&mdash;a Fortran to C converter
Authors: S. I. Feldman, D. M. Gay, M. W. Maimone, N. L. Schryer
Venue: ACM SIGPLAN Fortran Forum (1991)

We have produced a program that automatically converts ANSI standard Fortran 77 [1] to C [8]. It has converted many Fortran programs without manual intervention; it is easily available --- free of charge (and of warranty) --- by electronic mail and ftp.
A file system for continuous media
Authors: David P. Anderson, Yoshitomo Osawa, Ramesh Govindan
Venue: ACM Transactions on Computer Systems (TOCS) (1992)

The Continuous Media File System, CMFS, supports real-time storage and retrieval of continuous media data (digital audio and video) on disk. CMFS clients read or write files in &ldquo;sessions,&rdquo; each with a guaranteed minimum data rate. Multiple sessions, perhaps with different rates, and non-real-time access can proceed concurrently. CMFS addresses several interrelated design issues; real-time semantics fo sessions, disk layout, an acceptance test for new sessions, and disk scheduling policy. We use simulation to compare different design choices.
The Specification and Verified Decomposition of System Requirements Using CSP
Authors: A. P. Moore
Venue: IEEE Transactions on Software Engineering (1990)

A formal method for decomposing the critical requirements of a system into requirements of its component processes and a minimal, possibly empty, set of synchronization requirements is described. The trace model of Hoare's communicating sequential processes (CSP) is the basis for the formal method. The method is applied to an abstract voice transmitter and describes the role that the EHDM verification system plays in the transmitter's decomposition is described. In combination with other verification techniques, it is expected that this method will promote the development of more trustworthy systems.