ppxscal/embedding_network huggingface dataset:
Algorithm 715: SPECFUN–a portable FORTRAN package of special function routines and test drivers
Authors: W. J. Cody
Venue: ACM Transactions on Mathematical Software (TOMS) (1993)

SPECFUN is a package containing transportable FORTRAN special function programs for real arguments and accompanying test drivers. Components include Bessel functions, exponential integrals, error functions and related functions, and gamma functions and related functions.
A possible approach to object-oriented reengineering of Cobol programs
Authors: Marijana Tomic
Venue: ACM SIGSOFT Software Engineering Notes (1994)

Reengineering is rapidly becoming a recognized and important component of future computer-aided systems-engineering (CASE) environment. This paper presents framework for analyzing Object-Oriented Reengineering process of COBOL programs. The process embody software engineering principles that concern module interactions such as low coupling and high cohesion.
Plausible Justification Trees: A Framework for Deep and Dynamic Integration of Learning Strategies
Authors: Gheorghe Tecuci
Venue: Machine Learning (1993)

This article describes a framework for the deep and dynamic integration of learning strategies. The framework is based on the idea that each single-strategy learning method is ultimately the result of certain elementary inferences (like deduction, analogy, abduction, generalization, specialization, abstraction, concretion, etc.). Consequently, instead of integrating learning strategies at a macro level, we propose to integrate the different inference types that generate individual learning strategies. The article presents a concept-learning and theory-revision method that was developed in this framework. It allows the system to learn from one or from several (positive and/or negative) examples, and to both generalize and specialize its knowledge base. The method integrates deeply and dynamically different learning strategies, depending on the relationship between the input information and the knowledge base. It also behaves as a single-strategy learning method whenever the applicability conditions of such a method are satisfied.
On the complexity of equivalence between recursive and nonrecursive Datalog programs
Authors: Surajit Chaudhuri, Moshe Y. Vardi
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

In a previous paper, we have proved tight complexity bounds for the equivalence of recursive and nonrecursive Datalog programs: triply exponential time in general and doubly-exponential space for linear programs. In this paper, we show that under realistic restrictions on the classes programs under consideration, equivalence of recursive and nonrecursive programs can be less intractable; for the classes of programs we consider the complexity of equivalence ranges from NP to co-NEXPTIME.
The Minimal Test Set for Multioutput Threshold Circuits Implemented as Sorting Networks
Authors: Stanislaw J. Piestrak
Venue: IEEE Transactions on Computers (1993)

It is shown that an n-input sorting network (SN) can be used to implement an n-variable symmetric threshold functions using the least amount of hardware. An algorithm to derive Boolean functions implemented on any line of any n-input threshold circuit T/sup n/ implemented as a SN is given. A heuristic procedure for generating the minimal test set for any threshold circuit T/sup n/ implemented as a Batcher's SN or any other SN is presented. The number of tests required to detect all stuck-at faults in an n-input SN is determined. A highly regular structure using only one type of simple cell and a suitability for low-level pipelining are other advantages of the circuit T/sup n/. The circuit T/sup n/ can be used as a basic building block of various circuitry supporting the use of all known unidirectional error detecting codes.
Completely Regular Designs of Strength One
Authors: William J. Martin
Venue: Journal of Algebraic Combinatorics: An International Journal (1994)

We study a class of highly regular t-designs. These are the subsets of vertices of the Johnson graph which are completely regular in the sense of Delsarte &lsqb;2&rsqb;. In &lsqb;9&rsqb;, Meyerowitz classified the completely regular designs having strength zero. In this paper, we determine the completely regular designs having strength one and minimum distance at least two. The approach taken here utilizes the incidence matrix of (t+1)-sets versus k-sets and is related to the representation theory of distance-regular graphs &lsqb;1, 5&rsqb;.
The time dimension of neural network models
Authors: Richard Rohwer
Venue: ACM SIGART Bulletin (1994)

This review attempts to provide an insightful perspective on the role of time within neural network models and the use of neural networks for problems involving time. The most commonly used neural network models are defined and explained giving mention to important technical issues but avoiding great detail. The relationship between recurrent and feedforward networks is emphasised, along with the distinctions in their practical and theoretical abilities. Some practical examples are discussed to illustrate the major issues concerning the application of neural networks to data with various types of temporal structure, and finally some highlights of current research on the more difficult types of problems are presented.
A modified Adams method for nonstiff and mildly stiff initial value problems
Authors: J. R. Cash, S. Semnani
Venue: ACM Transactions on Mathematical Software (TOMS) (1993)

Adams predictor-corrector methods, and explicit Runge&ndash;Kutta formulas, have been widely used for the numerical solution of nonstiff initial value problems. Both of these classes of methods have certain drawbacks, however, and it has long been the aim of numerical analysts to derive a class of formulas that has the advantages of both Adams and Runge&ndash;Kutta methods and the disadvantages of neither! In this paper we derive a class of modified Adams formulas that attempts to achieve this aim. When used in a certain precisely defined predictor-corrector mode, these new formulas require three function evaluations per step, but have much better stability than Adams formulas. This improved stability makes the modified Adams formulas particularly effective for mildly stiff problems, and some numerical evidence of this is given. We also consider the performance of the new class of methods on the well-known DETEST test set to show their potential on general nonstiff initial value problems.
Thermodynamics and garbage collection
Authors: Henry G. Baker
Venue: ACM SIGPLAN Notices (1994)

We discuss the principles of statistical thermodynamics and their application to storage management problems. We point out problems which result from impercise usage of the terms information, state, reversible, conservative, etc.
Verification and testing in an object-oriented CS2 course
Authors: William J. Collins
Venue: ACM SIGPLAN OOPS Messenger (1993)

A model for verification and testing in an object-oriented CS2 course is presented. The model has four stages&mdash;two for verification and two for testing&mdash;at which student progress is evaluated. Students thereby see verification and testing as integral parts of the programming process, rather than as addenda. The impact of this model on students' programming behavior is discussed.
Workshop report: international workshop on distributed object management
Authors: M. Tamer Özsu, Umeshwar Dayal, Patrick Valduriez
Venue: ACM SIGMOD Record (1993)

The International Workshop on Distributed Object Management (IWDOM) was organized in Edmonton, Canada on the University of Alberta campus between August 19-21, 1992. The Workshop addressed the theory and practice of developing distributed object-oriented database management systems (OODBMS). The objective was to take note of the state-of-the-art in distributed object management technology and to identify the issues that need to be resolved. The recent developments in standards-related activities, notably the release of the CORBA specifications by the Object Management Group, contributed to the timeliness and importance of the Workshop.
Managing subjective information in fuzzy database systems
Authors: Hideo Tashiro, Naoto Ohki, Takahiko Nomura, Teruo Yokoyama, Yutaka Masushita
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

The recent improvement of computer hardware has made them possible to manage imprecise information. An example is the fuzzy database system which allows imprecise data as well as imprecise queries. However, one serious problem has not been solved when imprecise information is handled. That is, the problem of subjectivity. Each person has his/her own subjectivity, and the definition of a fuzzy expression usually differs among individuals. In this paper, we present a method for managing subjectivity in a fuzzy database system. In our system, the subjectivity for each user is interpreted, and membership functions are generated automatically for each user. This enables users to utilize the imprecise data which were initially stored by other users.
Shortest path by approximation in logic programs
Authors: Suzanne W. Dietrich
Venue: ACM Letters on Programming Languages and Systems (LOPLAS) (1992)

An approximation paradigm is proposed for logic programming as a simple modification to a complete evaluation strategy. The motivational example illustrates how a straigthforward transformation of a declarative specification of the distance between two vertices in a directed graph leads to sophisticated algorithms for computing shortest paths. The goal of the work presented in this paper is not to provide a more efficient computation of shortest paths but to investigate how the intermediate tables, known as extension tables, generated by the complete evaluation strategy might be used in approximation algorithms. We present the ETdistance algorithm in perspective, its execution is compared to those of Dijkstra's single-source and Floyd's all-pairs shortest path algorithms.
Odd memory systems may be quite interesting
Authors: André Seznec, Jacques Lenfant
Venue: ACM SIGARCH Computer Architecture News (1993)

Using a prime number of N of memory banks on a vector processor allows a conflict-free access for any slice of N consecutive elements of a vector stored with a stride not multiple of N. To reject the use of a prime (or odd) number N of memory banks, it is generally advanced that address computation for such a memory system would require systematic Euclidean Division by the number N. We first show that the well known Chinese Remainder Theorem allows to define a very simple mapping of data onto the memory banks for which address computation does not require any Euclidean Division. Massively parallel SIMD computers may have several thousands of processors. When the memory on such a machine is globally shared, routing vectors from memory to the processors is a major difficulty; the control for the interconnection network cannot be generally computed at execution time. When the number of memory banks and processors is a product of prime numbers, the family of permutations needed for routing vectors for memory to the processors through the interconnection network have very specific properties. The Chinese Remainder Network presented in the paper is able to execute all these permutations in a single path and may be self-routed.
Hierarchical performance modeling with MACS: a case study of the convex C-240
Authors: Eric L. Boyd, Edward S. Davidson
Venue: ACM SIGARCH Computer Architecture News (1993)

The MACS performance model introduced here can be applied to a Machine and Application of interest, the Compiler-generated workload, and the Scheduling of the workload by the compiler. The Ma, MAC, and MACS bounds each fix the named subset of M, A, C, and S while freeing the bound from the constraints imposed by the others. A/X performance measurement is used to measure access-only and execute-only code performance. Such hierarchical performance modeling exposes the gaps between the various bounds, the A/X measurements, and the actual performance, thereby focusing performance optimization at the appropriate levels in a systematic and goal-directed manner. A simple, but detailed, case study of the Convex C-240 vector mini-supercomputer illustrates the method.
Compression of indexes with full positional information in very large text databases
Authors: Gordon Linoff, Craig Stanfill
Venue: Proceedings of the 16th annual international ACM SIGIR conference on Research and development in information retrieval (1993)

This paper describes a combination of compression methods which may be used to reduce the size of inverted indexes for very large text databases. These methods are Prefix Omission, Run-Length Encoding, and a novel family of numeric representations called n-s coding. Using these compression methods on two different text sources (the King James Version of the Bible and a sample of Wall Street Journal Stories), the compressed index occupies less than 40% of the size of the original text, even when both stopwords and numbers are included in the index. The decreased time required for I/O can almost fully compensate for the time needed to uncompress the postings. This research is part of an effort to handle very large text databases on the CM-5, a massively parallel MIMD supercomputer.
Guaranteed-quality mesh generation for curved surfaces
Authors: L. Paul Chew
Venue: Proceedings of the ninth annual symposium on Computational geometry (1993)

For several commonly-used solution techniques for partial differential equations, the first step is to divide the problem region into simply-shaped elements, creating a mesh. We present a technique for creating high-quality triangular meshes for regions on curved surfaces. This technique is an extension of previous methods we developed for regions in the plane. For both flat and curved surfaces, the resulting meshes are guaranteed to exhibit the following properties: (1) internal and external boundaries are respected, (2) element shapes are guaranteed&mdash;all elements are triangles with angles between 30 and 120 degrees (with the exception of badly shaped elements that may be required by the specified boundary), and (3) element density can be controlled, producing small elements in &ldquo;interesting&rdquo; areas and large elements elsewhere. An additional contribution of this paper is the development of a practical generalization of Delaunay triangulation to curved surfaces.
A Second-Order Perturbation Expansion for the SVD
Authors: Richard J. Vaccaro
Venue: SIAM Journal on Matrix Analysis and Applications (1994)

Let $A$ be a rank-deficient matrix and let $N$ be a matrix whose norm is small compared with that of $A$. The left singular vectors of $A$ can be grouped into two matrices $U_1$ and $U_2$ whose columns provide orthonormal bases for the $p$-dimensional column space of $A$ and for its $n - p$ dimensional orthogonal complement. The left singular vectors of $\tilde{A} = A + N$ can also be partitioned into the first $p$ columns, $\tilde{U}_1$, and the last $n - p$ columns $\tilde{U}_2$. When analyzing a variety of signal processing algorithms, it is useful to know how different the spaces spanned by $U_1$ and $\tilde{U}_1$ (or $U_2$ and $\tilde{U}_2$) are. This question can be answered by developing a perturbation expansion for the subspace spanned by a set of singular vectors. A first-order expansion of this type has recently been developed and used to analyze the performance of direction-finding algorithms in array signal processing. In this paper, a new second-order expansion is derived and the result is illustrated with two examples.
Understanding and improving the user interface design process
Authors: Eric A. Fisch
Venue: ACM SIGSOFT Software Engineering Notes (1993)

Over the past few years user interfaces, especially graphical ones, have been emphasized in the design of computer systems [1]. Users often take for granted the interfaces of today's computer systems. The person entering data or typing up a report does not even consider the work that has gone into making the system and its applications as easy to use as a pen and paper. The difficulty that does go into creating the "perfect" user interface begins from the systems inception and does not end until the system becomes obsolete. Even then, the lasting effects of the interface on its users will make future designers work more laborious. This paper will discuss the design process of the user interface. It concludes with some suggestions that future designers may wish to consider to make their jobs easier.
Sweet harmony: the Talk/C++ connection
Authors: Harley Davis, Pierre Parquier, Nitsan Séniak
Venue: Proceedings of the 1994 ACM conference on LISP and functional programming (1994)

A tight, transparent, and portable integration between C++ and LISP is desirable and feasible. This paper describes the C++ interface supplied with, a modern LISP dialect which extends the proposed ISLisp standard with a module system, a metaobject protocol, and an extensive set of libraries. The interface parses C++ header files and generates C++ stub interface files, as well as TALK modules which implement proxy classes and TALK foreign function definitions for C++ functions. The programmer then has nearly complete access to the functionality of a C++ library.
The logical disk: a new approach to improving file systems
Authors: Wiebren de Jonge, M. Frans Kaashoek, Wilson C. Hsieh
Venue: Proceedings of the fourteenth ACM symposium on Operating systems principles (1994)

The Logical Disk (LD) defines a new interface to disk storage that separates file management and disk management by using logical block numbers and block lists. The LD interface is designed to support multiple file systems and to allow multiple implementations, both of which are important given the increasing use of kernels that support multiple operating system personalities.A log-structured implementation of LD (LLD) demonstrates that LD can be implemented efficiently. LLD adds about 5% to 10% to the purchase cost of a disk for the main memory it requires. Combining LLD with an existing file system results in a log-structured file system that exhibits the same performance characteristics as the Sprite log-structured file system.
Lag as a determinant of human performance in interactive systems
Authors: I. Scott MacKenzie, Colin Ware
Venue: Proceedings of the INTERACT '93 and CHI '93 conference on Human factors in computing systems (1993)

The sources of lag (the delay between input action and output response) and its effects on human performance are discussed. We measured the effects in a study of target acquisition using the classic Fitts' law paradigm with the addition of four lag conditions. At the highest lag tested (225 ms), movement times and error rates increased by 64% and 214% respectively, compared to the zero lag condition. We propose a model according to which lag should have a multiplicative effect on Fitts' index of difficulty. The model accounts for 94% of the variance and is better than alternative models which propose only an additive effect for lag. The implications for the design of virtual reality systems are discussed.
Ethics in technical communication: a rhetorical perspective
Authors: Gregory Clark
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1994)

Professional technical communicators and academicians who study and teach technical communication have opposing perspectives on the ethics that should guide the work of communicating technical information. Valuing most the well-being of their profession and the organizations in which they work, the professionals advocate an ethics in which competence is the principle and market success the purpose that guides good technical communication. The academicians, valuing most the well-being of the larger society in which all technology is situated, advocate an ethics in which responsibility is the guiding principle and the protection of that society's interests the guiding purpose. An alternative perspective founded upon rhetoric might be acceptable to both. Valuing the protection of all interests involved in a communication situation, this perspective makes cooperation the principle and compromise the purpose that should guide technical communication, suggesting an ethics in which open interaction and collaborative judgment become the context in which technical communication functions.
Optimal privacy and authentication on a portable communications system
Authors: Ulf Carlsen
Venue: ACM SIGOPS Operating Systems Review (1994)

Beller, Chang and Yacobi [2] have recently proposed a set of secret key and public key protocols to meet authentication and privacy requirements for conversation set-up protocols for the initiating party of portable communication systems. This paper improves upon the protocols to obtain a higher assurance of authentication and key distribution. Conversation set-up protocols for the responding party are discussed, a public key protocol providing end-to-end authentication and privacy is described, and relative as well as collective merits of the protocols are emphasised.
Managing CASE introduction: beyond software process maturity
Authors: Lars Mathiassen, Carsten Sørensen
Venue: Proceedings of the 1994 computer personnel research conference on Reinventing IS : managing information technology in changing organizations: managing information technology in changing organizations (1994)

Many software organizations face serious problems in their attempts to make expectations and realities meet in introduction of CASE technology. One promising and substantial approach to understand CASE introduction better and to provide guidelines for how to manage it more effectively has been developed by Watts S. Humphrey, Bill Curtis, and others. By relating CASE introduction to software process maturity they have provided a rich framework, both for analyzing and understanding the complexity of the implementation process, and for designing and managing specific implementation efforts.This paper reviews software process maturity as a framework for CASE introduction. The relevance of the framework is discussed and three critical questions are explored: 1) How do the specific characteristics of CASE technology influence CASE introduction? 2) How does the organizational environment influence CASE introduction? 3) What is the role of organizational experiments in CASE introduction? The aim of the paper is by way of this discussion to explicate the strengths and limits of software process maturity as a framework for CASE introduction, and to identify the most important supplementary issues.
Papyrus GIS demonstration
Authors: W. Hasan, M. Heytens, C. Kolovson, M.-A. Neimat, S. Potamianos, D. Schneider
Venue: Proceedings of the 1993 ACM SIGMOD international conference on Management of data (1993)

The goal of the Papyrus project [3] is to provide tools and services to enable the integration and parallelization of specialized data managers so that data-intensive applications can be constructed easily and efficiently. In our terminology, a data manager (DM) is a set of specialized methods that manage persistent data. A collection of functions defines the interface to a DM and provides the only means of accessing its persistent data.
Professional ethics from an academic perspective
Authors: Gregory Clark
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1994)

My work as a scholar and teacher during the seven years since I wrote "Ethics in Technical Communication: A Rhetorical Perspective" has been directed toward examining theories and histories of what I call the discourse of community. What I mean to describe by that term is the communication interaction people use to define and maintain the ground upon which they enact a variety of kinds of cooperation. Before I reflect on that essay in light of the four responses published here and what I have learned since I wrote it, I want to sketch the current state of my thinking about the discourse of community (see Clark 1994).