ppxscal/embedding_network huggingface dataset:
Invariant computations for analytic projective geometry
Authors: Walter Whiteley
Venue: Journal of Symbolic Computation (1991)

This paper focuses on two underlying questions for symbolic computations in projective geometry:IHow should a projective geometric property be written analytically? A first order formula in the language of fields which expresses a ''projective geometric property'' is translated, by an algorithm, into a restricted class of formulas in the analytic geometric language of brackets (or invariants). This special form corresponds to statements in synthetic projective geometry and the algorithm is a basic step towards translation back into synthetic geometry. IIHow are theorems of analytic geometry proven? Axioms for the theorems of analytic projective geometry are given in the invariant language. Identities derived form Hubert's Nullstellensatz then play a central role in the proof. Prom a proof of an open theorem about ''geometric properties'', over all fields, or over ordered fields, an algorithm derives Nullstellensatz identities - giving maximal algebraic simplicity, and maximal information in the proof. The results support the proposal that computational analytic projective geometry should be carried out directly with identities in the invariant language.
Algorithm 708: Significant digit computation of the incomplete beta function ratios
Authors: Armido R. Didonato, Alfred H. Morris,  Jr.
Venue: ACM Transactions on Mathematical Software (TOMS) (1992)

An algorithm is given for evaluating the incomplete beta function ratio Ix(a,b) and its complement 1 - Ix(a,b). A new continued fraction and a new asymptotic series are used with classical results. A transportable Fortran subroutine based on this algorithm is currently in use. It is accurate to 14 significant digits when precision is not restricted by inherent error.
Technical Note: \cal Q-Learning
Authors: Christopher J. C. H. Watkins, Peter Dayan
Venue: Machine Learning (1992)

\cal Q-learning (Watkins, 1989) is a simple way for agents to learn how to act optimally in controlled Markovian domains. It amounts to an incremental method for dynamic programming which imposes limited computational demands. It works by successively improving its evaluations of the quality of particular actions at particular states.This paper presents and proves in detail a convergence theorem for \cal Q-learning based on that outlined in Watkins (1989). We show that \cal Q-learning converges to the optimum action-values with probability 1 so long as all actions are repeatedly sampled in all states and the action-values are represented discretely. We also sketch extensions to the cases of non-discounted, but absorbing, Markov environments, and where many \cal Q values can be changed each iteration, rather than just one.
Invariant-theoretic methods in scene analysis and structural mechanics
Authors: Henry Crapo
Venue: Journal of Symbolic Computation (1991)

We discuss possible applications of invariant theory to unsolved problems in applied geometry. In particular, we discuss projective conditions for correctness of plane drawings of 3-dimensional geometric forms, and for special mechanical behavior of bar-and-joint structures.
A comparison of three current superscalar designs
Authors: Michael Laird
Venue: ACM SIGARCH Computer Architecture News (1992)

A standardized view of superscalar architectures is presented, and three current superscalar designs are comparedusing this framework. The designs studied are the Metaflow Light-ning SPARC, the IBM RS/6000, and the Intel i960MM.
Data path issues in a highly concurrent machine (abstract)
Authors: Augustus K. Uht, Darin B. Johnson
Venue: ACM SIGARCH Computer Architecture News (1992)

It is desirable to achieve high read bandwidths for the processing elements of highly concurrent SISD computers, both while keeping the register and memory write bandwidths low, and while keeping the interconnection networks simple. Solutions to these problems are proposed, simulated, verified, and measured. New techniques called write elimination and write liberation are presented that also greatly reduce the complexity of the data cache. The elimination of addressable hardware registers is also achieved.
A Three-Frame Algorithm for Estimating Two-Component Image Motion
Authors: James R. Bergen, Peter J. Burt, Rajesh Hingorani, Shmeul Peleg
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1992)

A fundamental assumption made in formulating optical-flow algorithms, that motion at any point in an image can be represented as a single pattern component undergoing a simple translation, fails for a number of situations that commonly occur in real-world images. An alternative formulation of the local motion assumption in which there may be two distinct patterns undergoing coherent (e.g. affine) motion within a given local analysis region is proposed. An algorithm for the analysis of two-component motion in which tracking and nulling mechanisms applied to three consecutive image frames separate and estimate the individual components is given. Precise results are obtained, even for components that differ only slightly in velocity as well as for a faint component in the presence of a dominant, masking component. The algorithm provides precise motion estimates for a set of elementary two-motion configurations and is robust in the presence of noise.
An Analysis on the Performance of Silicon Implementations of Backpropagation Algorithms for Artificial Neural Networks
Authors: Leonardo M. Reyneri, Enrica Filippi
Venue: IEEE Transactions on Computers (1991)

The effects of silicon implementation on the backpropagation learning rule in artificial neural systems are examined. The effects on learning performance of limited weight resolution, range limitations, and the steepness of the activation function are considered. A minimum resolution of about 20/22 bits is generally required, but this figure can be reduced to about 14/15 bits by properly choosing the learning parameter eta which attains good performance in presence of limited resolution. This performance can be further improved by using a modified batch backpropagation rule. Theoretical analysis is compared with ad-hoc simulations and results are discussed in detail.
Some theoretical problems when solving systems of polynomial equations using Gröbner bases
Authors: S. Alasdair Buchanan
Venue: ACM SIGSAM Bulletin (1991)

The use of Gr ouml;bner bases as an initial stage in determining the roots of systems of polynomials is well established as a more robust technique than numerical methods. The technique is described as producing 'the exact solution of systems of algebraic equations...'. However there are some theoretical limitations on the robustness of this method which under certain circumstances leave no confidence in its results. It is not the intention of this paper to provide answers to these problems but rather to consider their nature and the conditions under which they arise.
Information optimization for Monte Carlo data and application to high-temperature quantum chromodynamics
Authors: S. Huang, K. J. M. Moriarty, E. A. Myers, J. Potvin
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

Studying the thermodynamics of gases, lattices and other statistical systems via numerical simulations requires the mapping of energy density, pressure and other quantities as functions of temperature. Of special importance is the accurate mapping near and at phase transitions, where discontinuities are present and difficult to measure with a limited number of simulations. This is particularly true for Quantum Chromodynamics, the theory of quarks and gluons, which is known to have a first-order phase transition at a temperature of about 150 MeV. We show that by using the recently proposed method of density of states, one can optimize the information obtained from these limited simulations in order to obtain in the worst cases the derivative of the thermodynamical functions, and in the best cases, their entire curve over a wide range of temperatures.
The use of Taylor series to test accuracy of function programs
Authors: W. J. Cody, L. Stoltz
Venue: ACM Transactions on Mathematical Software (TOMS) (1991)

This paper discusses the use of local Taylor series expansions for determining the accuracy of computer programs for special functions. The main example is testing of programs for exponential integrals. Additional applicaitons include testing of programs for certain Bessel functions, Dawson's integral, and error functions.
Reply to Ehrad Konrad: Application of measurement theory to software metrics&mdash;comments on the Bollmann-Zuse approach
Authors: Horst Zuse, Peter Bollmann-Sdorra
Venue: ACM SIGPLAN Notices (1992)

This paper is the reply to the paper "Erhard Konrad: Application of Measurement Theory to Software Metrics - Comments on the Bollmann-Zuse Approach" which is also published in this issue (November 92) of SlGPLAN Notices. Konrad is criticizing our approach: "Horst Zuse; Peter Bollmann: Using Measurement Theory to Describe the Properties and Scales of Software Complexity Metrics", which was published in SlGPLAN Notices (8)89. Konrad criticized the first time our paper in SIGPLAN Notices in March 1991. We replied in SlGPLAN Notices May 1991 to this criticism. In this issue (November 1992) Konrad imputes again that we have failed to achieve our goals of refuting his criticism. We will show that Konrad has a totally different view of established concepts of measurement theory as treated by Roberts, Krantz, Luce, Suppes and Tversky.
The computer sciences electronic magazine: translating from paper to multimedia
Authors: W. Randall Koons, Anne M. O'Dell, Nancy J. Frishberg, Mark R. Laff
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

In this paper, we discuss issues in design and usability of the IBM Computer Sciences Electronic Magazine (CSEM). The CSEM is an interactive multimedia translation of a paper magazine. It contains articles describing Computer Sciences projects at the four IBM Research Labs. Combining aspects from print, television, and computers, it is a useful vehicle for studying what we see as a completely new communication medium. We report both our design rationale in creating the magazine and the results of several user studies which helped us understand our successes and failures. These studies are a part of an iterative process through which we have redesigned and improved the CSEM.
Paradigms for process interaction in distributed programs
Authors: Gregory R. Andrews
Venue: ACM Computing Surveys (CSUR) (1991)

Distributed computations are concurrent programs in which processes communicate by message passing. Such programs typically execute on network architectures such as networks of workstations or distributed memory parallel machines (i.e., multicomputers such as hypercubes). Several paradigms&mdash;examples or models&mdash;for process interaction in distributed computations are described. These include networks of filters, clients, and servers, heartbeat algorithms, probe/echo algorithms, broadcast algorithms, token-passing algorithms, decentralized servers, and bags of tasks. These paradigms are appliable to numerous practical problems. They are illustrated by solving problems, including parallel sorting, file servers, computing the topology of a network, distributed termination detection, replicated databases, and parallel adaptive quadrature. Solutions to all problems are derived in a step-wise fashion from a general specification of the problem to a concrete solution. The derivations illustrate techniques for developing distributed algorithms.
A Design and Yield Evaluation Technique for Wafer-Scale Memory
Authors: Koichi Yamashita, Shohei Ikehara
Venue: Computer (1992)

Wafer-scale memory provides greater yet cheaper storage volume than conventional memory systems using discrete chips. A simulator using a Monte Carlo technique to evaluate the defect tolerance scheme for a wafer-scale memory and predict the harvested capacity of the wafer memory is described. The design of a wafer-scale random-access memory that uses switching-register network logic is presented. A simulator that selects the optimal defect tolerance scheme for the wafer-scale memory is discussed.
An overview of the A architecture for optimisation problems in a logic programming environment
Authors: D. P. Rodohan, R. J. Glover
Venue: ACM SIGARCH Computer Architecture News (1991)

Search of a state space is a common function in artificial intelligence applications consuming a large proportion of the total processing time. In this paper we propose a hierarchical architecture using content addressable memory to accelerate the A* algorithm in a Prolog system and remove the associated high memory overheads.
VAR analysis: a framework for justifying strategic information systems projects
Authors: Ting-Peng Liang, Ming-Je Tang
Venue: ACM SIGMIS Database (1992)

Recently, strategic implications of information technology have attracted much attention. Many successful applications have been analyzed and frameworks have been developed to help firms identify opportunities for applying strategic information systems (SIS). However, little research has studied how these strategic opportunities can be evaluated. Previous applications of SIS have indicated that competitive advantages are not guaranteed and risks always exist. Hence, for a firm pursuing strategic uses of information technology, careful evaluation of potential opportunities before their implementation is crucial. In this article we present a competition-oriented approach to analyzing potential competitive advantages. This approach enhances the traditional cost-benefit analysis to fit the need for evaluating SIS. It consists of three major modules: value analysis, advantage analysis, and risk analysis. An example showing how a project having negative net present values can become feasible in VAR analysis is illustrated.
Construction of test problems in quadratic bivalent programming
Authors: Panos M. Pardalos
Venue: ACM Transactions on Mathematical Software (TOMS) (1991)

A method of constructing test problems for constrained bivalent quadratic programming is presented. For any feasible integer point for a given domain, the method generates quadratic functions whose minimum over the given domain occurs at the selected point. Certain properties of unconstrained quadratic zero-one programs that determine the difficulty of the test problems are also discussed. In addition, a standardized random test problem generator for unconstrained quadratic zero-one programming is given.
&ldquo;Higher-order&rdquo; logic as a data model
Authors: Sanjay Manchandra
Venue: Proceedings of the second international workshop on Database programming languages (1989)

A higher-order logic is introduced for increasing the modeling and programming capabilities of deductive databases. The logic supports structured data, object identity and sets. The logic is not truly higher-order but it can be mapped rather directly into first-order logic. The mapping ensures computability and promises an efficient implementation obtained by generalizing known techniques for implementing logic programs and databases. The logic is used to extend Datalog to Higher-Order Datalog: a language for computing with labeled sets. Several applications of the language are discussed. Higher-Order Datalog supports a template mechanism for defining the database schema and structuring database programs.
Open CSCW systems
Authors: Henrik Lewe, Volker Barent
Venue: ACM SIGOIS Bulletin (1992)

It is proposed to design "Open CSCW Systems" tailorable along the content and process dimensions of group tasks and their domains. A refineable architecture for the process dimension is suggested. Whether this idea leads to a better support of groupwork has to be evaluated by prototypes.
The influences of fault type and topology on fault model performance and the implications to test and testable design
Authors: Kenneth M. Butler, M. Ray Mercer
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

A new method, Difference Propagation, is proposed to analyze fault models in combinational circuits. It propagates Boolean functional information represented by ordered binary decision diagrams. Results are presented concerning exact detectabilities and syndromes for a set of benchmark circuits. The data suggest answers to open questions in CAD and represent the first data of this type for bridging faults. The information is shown to affect testable design as well as test generation.
The dual structure of ordered trees
Authors: Gérard A. Langlet
Venue: Proceedings of the international conference on APL '91 (1991)

Although they were described by K. Iverson in his 1962 book [1], ordered trees have never been implemented as APL objects. However, APL2 as well as ISO-APL, provide many facilities to handle them. This paper illustrates with simple examples, the duality between the tree-structure and what will be presented as an "object-oriented definition structure". APL functions are proposed to facilitate the conversion of one form into the other one. Trees have great utility in data base processing, as well in science, as in business applications. Interfaces with the "outer world" - e.g. word processors, or LISP and PROLOG can become easy to build with the help of this simple concept of duality.
Phoneme-in-context modeling for dragon's continuous speech recognizer
Authors: Paul Bamberg, Laurence Gillick
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

For large-vocabulary continuous speech recognition, the goal of training is to model phonemes with enough precision so that from the models one could reconstruct a sequence of acoustic parameters that accurately represents the spectral characteristics of any naturally-occurring sentence, including all coarticulation effects that arise either between phonemes in a word or across word boundaries. The aim at Dragon Systems is to collect and process enough training data to accomplish this goal for all of natural spoken English rather than for any one restricted task.The basic unit that must be trained is the "phoneme in context" (PIC), a sequence of three phonemes accompanied by a code for prepausal lengthening. At present, syllable and word boundaries are ignored in defining PICs.More than 16,000 training tokens, half isolated words and half short phrases, were phonemically labeled by a semi-automatic procedure using hidden Markov models. To model a phoneme in a specific context, a weighted average is constructed from training data involving the desired context and acoustically similar contexts.For use in HMM continuous-speech recognition, each PIC is converted to a Markov model that is a concatenation of one to six node models. No phoneme, in all its contexts, requires more than 64 distinct nodes, and the total number of node models ("phonemic segments") required to construct all PICs is only slightly more than 2000. As a result, the entire set of PICs can be adapted to a new speaker on the basis of a couple of thousand isolated words or a few hundred sentences of connected speech.The advantage of this approach to training is that it is not task-specific. From a single training database, Dragon Systems has constructed models for use in a 30,000-word isolated-word recognizer, for connected digits, and for two different thousand-word continuous-speech tasks.
Standards factor: The CHI'91 Standards SIG session
Authors: Pat Billingsley
Venue: ACM SIGCHI Bulletin (1991)

The second annual SIG session on user interface standards was held at CHI'91 on Tuesday morning, April 30th. Approximately 200 people managed to find seats in the meeting room, and many additional people sat or stood in the doorways and adjoining areas. (Considering the continuing high level of interest in this topic, we anticipate being assigned a larger meeting room for CHI'92.)
Failure recovery in the MICON system
Authors: Ajay Daga, William P. Birmingham
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

MICON is a knowledge-based system that designs small computer systems. The synthesis of a digital system may be viewed as successive design and redesign of individual subsystems. Redesign is necessary when the design of one subsystem imposes conflicting requirements on the design of another, and when a design cannot meet specifications. This paper discusses the technique used to make MICON capable of redesign. The paper discusses a dependency network used to facilitate failure correction and highlights the novel features of this scheme. An example is given.
Operations on sets in an OODB
Authors: Jorn Andersen, Trygve Reenskaug
Venue: ACM SIGPLAN OOPS Messenger (1991)

In this article we express some ideas on how to select an arbitrary set of objects, or to combine objects and information in the objects, in an arbitrary way. In the following will an object-oriented database be thought of as a collection of sets. The sets are collections of objects which all share a common message protocol. Operations originating from relational algebra are defined on these sets. To make the retrieval of objects efficient, a storage strategy for objects is developed. Combination of objects and changes in the objects' message protocol as a result of a retrieval request, are solved by a filtering mechanism.
Reconciling environment integration and software evolution
Authors: Kevin J. Sullivan, David Notkin
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1992)

Common software design approaches complicate both tool integration and software evolution when applied in the development of integrated environments. We illustrate this by tracing the evolution of three different designs for a simple integrated environment as representative changes are made to the requirements. We present an approach that eases integration and evolution by preserving tool independence in the face of integration. We design tool integration relationships as separate components called mediators, and we design tools to implicitly invoke mediators that integrate them. Mediators separate tools from each other, while implicit invocation allows tools to remain independent of mediators. To enable the use of our approach on a range of platforms, we provide a formalized model and requirements for implicit invocation mechanisms. We apply this model both to analyze existing mechanisms and in the design of a mechanism for C++.
Pad placement and ring routing for custom chip layout
Authors: Deborah C. Wang
Venue: Proceedings of the 27th ACM/IEEE Design Automation Conference (1991)

This paper presents an optimum scheme for interconnecting the chip core and the I/O pads in the final stage of physical design. The pad placement routine, based on linear assignment, determines the dimension of the pad ring and selects the optimum position for each pad with the objective of minimizing the chip area and the total wire length. The router is based on a channel routing algorithm which incorporates additional features to address the special needs of the ring configuration. It attempts to achieve 100% routing completion in a rectangular ring-shaped area with two interconnect layers. The complete package has been implemented as part of the BEAR Layout System for custom chip design.