ppxscal/embedding_network huggingface dataset:
The computer science fair: an alternative to the computer programming contest
Authors: Sue Fitzgerald, Mary Lou Hines
Venue: ACM SIGCSE Bulletin (1996)

Dissatisfaction with the results of programming contest events has led to the development of a new type of competitive event, a computer science fair. The computer science fair, a combination art show/science fair, is designed to attract a wider diversity of participants, to encourage creativity, and to reinforce good project development practices. Students are asked to creatively use technology to express themselves, to design new inventions, and to solve problems by submitting projects in the following categories: 1) computers and the arts and humanities --- computer music, computer art, multimedia projects; 2) computer programs --- entertainment, education, scientific, business, modeling and simulation; and 3) computer or electronically controlled inventions. This paper outlines the rules for submissions and judging of projects and the results of the First Annual Kansas City Computer Science Fair. Results based on gender and age category are reported.
On the efficiency of subsumption algorithms
Authors: G. Gottlob, A. Leitsch
Venue: Journal of the ACM (JACM) (1985)

The costs of subsumption algorithms are analyzed by an estimation of the maximal number of unification attempts (worst-case unification complexity) made for deciding whether a clause C subsumes a clause D. For this purpose the clauses C and D are characterized by the following parameters: number of variables in C, number of literals in C, number of literals in D, and maximal length of the literals. The worst-case unification complexity immediately yields a lower bound for the worst-case time complexity. First, two well-known algorithms (Chang-Lee, Stillman) are investigated. Both algorithms are shown to have a very high worst-case time complexity. Then, a new subsumption algorithm is defined, which is based on an analysis of the connection between variables and predicates in C. An upper bound for the worst-case unification complexity of this algorithm, which is much lower than the lower bounds for the two other algorithms, is derived. Examples in which exponential costs are reduced to polynomial costs are discussed. Finally, the asymptotic growth of the worst-case complexity for all discussed algorithms is shown in a table (for several combinations of the parameters).
ATM concepts, architectures, and protocols
Authors: Ronald J. Vetter
Venue: Communications of the ACM (1995)

Asynchronous transfer mode (ATM) is often described as the future computer networking paradigm that will bring high-speed communications to the desktop. What is ATM? How is it different from today's networking technologies? This article is intended to acquaint readers with this emerging technology and describe some of the concepts embodied within it. In order to understand why ATM was created and how it works, we first need to review a bit of computer networking history.
An Operator Splitting Method for the Wigner--Poisson Problem
Authors: Anton Arnold, Christian Ringhofer
Venue: SIAM Journal on Numerical Analysis (1996)

The Wigner--Poisson equation describes the quantum-mechanical motion of electrons in a self-consistent electrostatic field. The equation consists of a transport term and a non-linear pseudodifferential operator. In this paper we analyze an operator splitting method for the linear Wigner equation and the coupled Wigner--Poisson problem. For this semidiscretization in time, consistency and nonlinear stability are established in an L2-framework. We present a numerical example to illustrate the method.
Coordinated allocation of memory and processors in multiprocessors
Authors: Eric W. Parsons, Kenneth C. Sevcik
Venue: Proceedings of the 1996 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1996)

An important issue in multiprogrammed multiprocessor systems is the scheduling of parallel jobs. Most research in the area has focussed solely on the allocation of processors to jobs. However, since memory is also a critical resource for many parallel jobs, the allocation of memory and processors must be coordinated to allow the system to operate most effectively.To understand how to design such coordinated scheduling disciplines, it is important to have a theoretical foundation. To this end, we develop bounds on the achievable system throughput when both memory and processing time are in demand. We then propose and simulate a simple discipline and relate its performance to the throughput bounds. An important result of our work is for the situation in which the workload speedup is convex (from above), but the speedup characteristics of individual jobs are unknown. It shows that an equi-allocation strategy for processors can achieve near-maximum throughput, yet offer good mean response times, when both memory and processors are considered.
Optimizing queries over multimedia repositories
Authors: Surajit Chaudhuri, Luis Gravano
Venue: ACM SIGMOD Record (1996)

Repositories of multimedia objects having multiple types of attributes (e.g., image, text) are becoming increasingly common. A selection on these attributes will typically produce not just a set of objects, as in the traditional relational query model (filtering), but also a grade of match associated with each object, indicating how well the object matches the selection condition (ranking). Also, multimedia repositories may allow access to the attributes of each object only through indexes. We investigate how to optimize the processing of queries over multimedia repositories. A key issue is the choice of the indexes used to search the repository. We define an execution space that is search-minimal, i.e., the set of indexes searched is minimal. Although the general problem of picking an optimal plan in the search-minimal execution space is NP-hard, we solve the problem efficiently when the predicates in the query are independent. We also show that the problem of optimizing queries that ask for a few top-ranked objects can be viewed, in many cases, as that of evaluating selection conditions. Thus, both problems can be viewed together as an extended filtering problem.
Symbolic analysis for parallelizing compilers
Authors: Mohammad R. Haghighat, Constantine D. Polychronopoulos
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1996)

The notion of dependence captures that most important properties of a program for efficient execution on parallel computers. The dependence structure of a program defines that necessary constraints of the order of execution of the program components and provides sufficient information for the exploitation of the available parallelism. Static discovery and management of the dependence structure of programs save a tremendous amount of execution time, and dynamic utilization of dependence information results in a significant performance gain on parallel computers. However, experiments with parallel computers indicate that existing multiprocessing environments are unable to deliver the desired performance over a wide range of real applicatins, mainly due to lack of precision of their dependence information. This calls for an effective compilation scheme capable of understanding the dependence structure of complicated application programs. This article describes a methodology for capturing analyzing program properties that are essential in the effective detection and efficient exploitation of parallelism on parallel computers. Based on this methodology, a symbolic analysis framework is developed for the Parafrase-2 parallelizing compiler. This framework extends the scope of a variety of important program analysis problems and solves them in a unified way. The attained solution space of these problems is much larger than that handled by existing compiler technology. Such a powerful approach is required for the effective compilation of a large class of application programs. programs.
Managing video data in a mobile environment
Authors: Rafael Alonso, Yuh-Lin Chang, Liviu Iftode, V. S. Mani
Venue: ACM SIGMOD Record (1995)

Two key technological trends of the last few years have been the emergence of handheld computational elements and the implementation of practical wireless communication networks. These two changes have made mobile computer systems feasible. While there has been much research interest devoted to mobile computer issues, such systems have not yet been commercially successful. This has been ascribed to the lack of a killer mobile app. We believe that the support of video on mobile systems will indeed make possible many new interesting applications. However, providing mobile video is a non-trivial task, and much work needs to be done before practical systems are widely available. In this short note we address the issue of mobile multimedia from a practitioner's perspective. We note what software and hardware are currently available in the market in support of mobile multimedia, and point out some of their deficiencies. We also discuss some of the communication and data management research issues that need to be tackled in order to address said deficiencies. Exploring these research issues is the focus of our project.
Programming with Fortran
Authors: Neville Holmes
Venue: ACM SIGPLAN Fortran Forum (1995)

Changes made to, and proposed for, Fortran seem to be directed to improving the code that can be written in it. At the same time, supporters of Fortran deplore Fortran's declining popularity, and suggest improvements to improve Fortran code further. However, Fortran's popularity might be boosted by making it a better system to program in by providing support for the programming process rather than improving the product.
Fundamental techniques for order optimization
Authors: David Simmen, Eugene Shekita, Timothy Malkemus
Venue: ACM SIGMOD Record (1996)

Decision support applications are growing in popularity as more business data is kept on-line. Such applications typically include complex SQL queries that can test a query optimizer's ability to produce an efficient access plan. Many access plan strategies exploit the physical ordering of data provided by indexes or sorting. Sorting is an expensive operation, however. Therefore, it is imperative that sorting is optimized in some way or avoided all together. Toward that goal, this paper describes novel optimization techniques for pushing down sorts in joins, minimizing the number of sorting columns, and detecting when sorting can be avoided because of predicates, keys, or indexes. A set of fundamental operations is described that provide the foundation for implementing such techniques. The operations exploit data properties that arise from predicate application, uniqueness, and functional dependencies. These operations and techniques have been implemented in IBM's DB2/CS.
An auxiliary processor to integrate MATLAB with APL
Authors: Kedar Gidh
Venue: ACM SIGAPL APL Quote Quad (1995)

To augment the functionality of APL, an auxiliary processor was implemented to access MATLAB. This provides APL users the capability to use MATLAB's presentation-quality graphics and application-specific toolboxes from within APL. Data arrays can be exchanged between APL and MATLAB using the auxiliary processor. The auxiliary processor was written in C to be used under Unix.
Simulation and cross docking
Authors: Matthew Rohrer
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Cross docking is a material handling and distribution concept in which goods move directly from receiving to shipping. In a typical cross docking system, the primary objective is to eliminate storage and excessive handling. As companies continue to streamline distribution functions, cross docking is becoming a more widely accepted distribution method. The benefits of cross docking include reduced inventory, increased customer responsiveness, and better control of the distribution operation. By definition, cross docking systems require: a close connection between receiving and shipping operations This connection calls for robust hardware and software systems to solve the cross docking problem. Simulation reduces some of the risk involved with cross docking systems. The paper describes how simulation helps ensure success in cross docking systems by determining optimal hardware configuration and software control, as well as establishing failure strategies before cross docking problems are encountered. Modeling methods and issues are also discussed as they apply to cross docking. The paper is oriented toward simulation practitioners who need to model cross docking systems, as well as distribution managers who are evaluating cross docking.
Eliminating event cancellation in discrete event simulation
Authors: Eric L. Savage, Lee W. Schruben
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The cancellation of previously scheduled events not only results in a model running less efficiently, it precludes the application of some analysis techniques such as infinitesimal perturbation analysis. While same simulation languages (SIMSCRIPT, SIGMA) include an explicit facility for event cancellation, others do not (SLAM, GPSS, SIMAN). From computation theory, it is known that event cancellation is never necessary; but it is sometimes a convenient modeling technique. Unfortunately, there has been no general methodology developed for eliminating event cancellation from a simulation model. We present a simple general approach. Applications to two classical models where event cancellation is typically used serve as illustrations of the method.
Similarity metric learning for a variable-kernel classifier
Authors: David G. Lowe
Venue: Neural Computation (1995)

Nearest-neighbor interpolation algorithms have many useful properties for applications to learning, but they often exhibit poor generalization. In this paper, it is shown that much better generalization can be obtained by using a variable interpolation kernel in combination with conjugate gradient optimization of the similarity metric and kernel size. The resulting method is called variable-kernel similarity metric (VSM) learning. It has been tested on several standard classification data sets, and on these problems it shows better generalization than backpropagation and most other learning methods. The number of parameters that must be determined through optimization are orders of magnitude less than for backpropagation or radial basis function (RBF) networks, which may indicate that the method better captures the essential degrees of variation in learning. Other features of VSM learning are discussed that make it relevant to models for biological learning in the brain.
On the minimality and global consistency of row-convex constraint networks
Authors: Peter van Beek, Rina Dechter
Venue: Journal of the ACM (JACM) (1995)

Constraint networks have been shown to be useful in formulating such diverse problems as scene labeling, natural language parsing, and temporal reasoning. Given a constraint network, we often wish to (i) find a solution that satisfies the constraints and (ii) find the corresponding minimal network where the constraints are as explicit as possible. Both tasks are known to be NP-complete in the general case. Task (1) is usually solved using a backtracking algorithm, and task (ii) is often solved only approximately by enforcing various levels of local consistency. In this paper, we identify a property of binary constraint called row convexity and show its usefulness in deciding when a form of local consistency called path consistency is sufficient to guarantee that a network is both minimal and globally consistent. Globally consistent networks have the property that a solution can be found without backtracking. We show that one can test for the row convexity property efficiently and we show, by examining applications of constraint networks discussed in the literature, that our results are useful in practice. Thus, we identify a class of binary constraint networks for which we can solve both tasks (i) and (ii) efficiently. Finally, we generalize the results for binary constraint networks to networks with nonbinary constraints.
Algorithm 748: enclosing zeros of continuous functions
Authors: G. E. Alefeld, F. A. Potra, Yixun Shi
Venue: ACM Transactions on Mathematical Software (TOMS) (1995)

Two efficient algorithms for enclosing a zero of a continuous function are presented. They are similar to the recent methods, but together with quadratic interpolation they make essential use of inverse cubic interpolation as well. Since asymptotically the inverse cubic interpolation is always chosen by the algorithms, they achieve higher-efficiency indices: 1.6529&hellip; for the first algorithm, and 1.6686&hellip; for the second one. It is proved that the second algorithm is optimal in a certain family. Numerical experiments show that the two new methods compare well with recent methods, as well as with the efficient solvers of Dekker, Brent, Bus and Dekker, and Le. The second method from the present article has the best behavior of all 12 methods especially when the termination tolerance is small.
A timing-driven data path layout synthesis with integer programming
Authors: Jaewon Kim, S. M. Kang
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

We propose an efficient data path synthesis algorithm which generates bit-sliced layouts. Since data path circuits have special characteristics which are different from those of random logic circuits, the dedicated synthesis system is required for efficient layouts. Our main goal in the data path synthesis is to satisfy the timing constraints of circuits as well as to reduce layout areas. Timing-driven placement and over-the-cell routing techniques are developed to generate data path modules. Also, signal interfaces between bit-slices are carefully considered to further reduce layout areas. Our synthesis techniques take advantage of the common characteristics of data path structures under timing constraints and applies mixed integer linear programming approach to solve the problem. The superior results from our data path synthesis system are demonstrated through comparison with the layout results with the simulated annealing technique.
A web interface to parallel program source code archetypes
Authors: Juan Villacis, Dennis Gannon
Venue: Proceedings of the 1995 ACM/IEEE conference on Supercomputing (CDROM) (1995)

This paper describes a set of tools for annotating and exploring program source code on the World Wide Web (WWW). These tools are part of a project to build an electronic textbook for parallel programming that exploits the Caltech Archetypes model of program construction. The tools provide a simple way for Fortran, HPF and C++ programmers to add special annotations to source codes that allow the source code to be converted automatically into WWW hypertext documents. In addition, special compiler based tools examine the source code and discover all subroutine call sites and automatically build the hypertext links to the appropriate subroutine definitions. In the case of parallel C++, a complete class browser has been constructed in HTML and the compiler based tools generates the data base of application specific type and program information.
OO anthropology (panel): crossing the chasm
Authors: Steven D. Fraser, Alistair Cockburn Jim Coplien, Larry Constantine, Dave West, Leo Brajkovich
Venue: Proceedings of the 11th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (1996)

Anthropology is the study of civilization, particularly its societies, customs, structure, and evolution. Our premise is that there are cultureal "chasms" to be crossed to ensure the success of the technological beachhead established by innovators and early adopters of the OO paradigm. Our panelists will address the following questions: bull;What anthropological cultural factors have to be "matured" (and how?) to foster the success of the OO paradigm? bull;What mechanisms are required to facilitate communications between cultures of differing maturity? bull;What cultural chasms must be crossed to develop a successful organization/culture within the framework supported by the object-oriented paradigm (or more perrversely, is there anything "special" about the OO paradigm)?This panel will interest pracitioners as a forum to share and debate experiences related to our current-day software culture metamorphosis.
PCF extended with real numbers
Authors: Martín Hötzel Escardó
Venue: Theoretical Computer Science (1996)

We extend the programming language PCF with a type for (total and partial) real numbers. By a partial real number we mean an element of a cpo of intervals, whose subspace of maximal elements (single-point intervals) is homeomorphic to the Euclidean real line. We show that partial real numbers can be considered as &ldquo;continuous words&rdquo;. Concatenation of continuous words corresponds to refinement of partial information. The usual basic operations cons, head and tail used to explicitly or recursively define functions on words generalize to partial real numbers. We use this fact to give an operational semantics to the above referred extension of PCF. We prove that the operational semantics is sound and complete with respect to the denotational semantics. A program of real number type evaluates to a head-normal form iff its value is different from &bottom; ; if its value is different from &bottom; then it successively evaluates to head-normal forms giving better and better partial results converging to its value. &mdash;Author's Abstract
Integrating rate monotonic analysis into the preliminary Ada design process
Authors: Kevin J. Cronin
Venue: ACM SIGAda Ada Letters (1995)

High quality software is easier to understand, maintain and reuse. The quality of real-time systems is often measured in how well they meet their critical timing requirements as well as their computational requirements. Management and practitioners need to know early on in the development process if what they are designing will meet its critical timing requirements. The Rate Monotonic Analysis (RMA) theory and guidelines for its usage in Ada designs are reviewed. This paper proposes extending this work to include the integration of RMA as a design metric when evaluating the timing correctness of preliminary Ada programs.
Teaching inheritance versus inclusion to first year computer science students
Authors: Kenneth A. Reek
Venue: Proceedings of the twenty-seventh SIGCSE technical symposium on Computer science education (1996)

This paper describes two laboratory experiments used at the Rochester Institute of Technology to teach first year CS students the difference between inheritance and inclusion (aggregation, composition).
Document Image Decoding by Heuristic Search
Authors: Anthony C. Kam, Gary E. Kopec
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

This correspondence describes an approach to reducing the computational cost of document image decoding by viewing it as a heuristic search problem. The kernel of the approach is a modified dynamic programming (DP) algorithm, called the iterated complete path (ICP) algorithm, that is intended for use with separable source models. A set of heuristic functions are presented for decoding formatted text with ICP. Speedups of 3-25 over DP have been observed when decoding text columns and telephone yellow pages using ICP and the proposed heuristics.