ppxscal/embedding_network huggingface dataset:
The rapport multimedia conferencing system
Authors: S. R. Ahuja, J. Robert Ensor, David N. Horn
Venue: Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems (1988)

This paper describes the design and initial implementation of the Rapport multimedia conferencing system, which supports interactive, real-time, distributed conferences among two or more users. Using computers connected by data and voice networks, this system creates an environment in which many sorts of meetings can take place, including telephone conversations, discussions among colleagues, and lectures. Rapport provides new opportunities for meetings, allowing a user to interact with distant colleagues and to participate in several conferences concurrently at his or her workstation. The system allows many existing computer programs to be used, unmodified, within its conferencing environment. Thus computer-generated data and displays are available to the conferees for manipulation and editing, enhancing the exchange of information during meetings. Although Rapport does not encourage a particular methodology of meeting conduct, such specialized support can be built using Rapport. The paper outlines Rapport's conference abstraction and the model on which it is based &mdash; the &ldquo;virtual meeting room.&rdquo; It then presents an overview of Rapport's architecture, discusses the system's environmental requirements, and concludes by mentioning some of our plans for future work with Rapport.
Space-time tradeoffs for orthogonal range queries
Authors: P M Vaidya
Venue: Proceedings of the seventeenth annual ACM symposium on Theory of computing (1985)

We investigate the question of (storage) space - (retrieval) time tradeoff for orthogonal range queries on a static database. Lower bounds on the product of retrieval time and storage space are obtained in the arithmetic and tree models.
A &ldquo;gridless&rdquo; variable-width channel router for marco cell design
Authors: C. H. Ng
Venue: Proceedings of the 24th ACM/IEEE Design Automation Conference (1987)

In this paper, we present a channel router especially designed for routing macro cells. The router routes variable-width pins with wires of any width. Although the router uses a routing grid internally, it acts like it is completely gridless to the user. Pins along the top and the bottom edges of the channel can be at any X-location, and the router uses a channel compactor to compact all horizontal segments vertically. The router allows pins to be on either of the two routing layers. If all the power pins are on the same layer, the router routes the whole power bus in one single layer. It handles non-rectangular channels with highly irregular heights, and it also handles cyclic vertical constraints. Finally, the router has been tested with a number of industrial circuits.
Action research on systems development: case study of changing actor roles
Authors: Siv Friis
Venue: ACM SIGCAS Computers and Society (1988)

The purpose of this paper is to discuss the change of roles of the actors (users and Data Processing experts) in an action research project of systems development, where all actors participated actively in the project. The users participated in the actual system construction by building small prototype systems that acted as requirements specifications. There is a description of the types of roles the users as well as the experts took on in the project. Questions regarding the social and economic risks with end user computing are discussed. The changing of roles and its social consequences are discussed in the perspective of role theory and interactionist socialization theory.
Employing voice back channels of facilitate audio document retrieval
Authors: Chris Schmandt
Venue: Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems (1988)

Human listeners use voice back channels to indicate their comprehension of a talker's remarks. This paper describes an attempt to build a user interface capable of employing these back channel responses for flow control purposes while presenting a variety of audio information to a listener. Acoustic evidence based on duration and prosody (rhythm and melody) of listeners' utterances is employed as a means of discriminating responses by discourse function without using word recognition. Such an interface has been applied to three tasks: speech synthesis of driving directions, speech synthesis of electronic mail, and retrieval of recorded voice messages.
Pascal-FC: a language for teaching concurrent programming
Authors: A. Burns, G. Davies
Venue: ACM SIGPLAN Notices (1988)

Pascal-FC is an extension of one of Wirth's simple Pascals. The added features allow processes to be specified and executed concurrently. Moreover communication and synchronisation primitives have been added to support semaphores, monitors and the CSP/occam type rendezvous. The language is used to give computer science students practical experience of a range of concurrency models.
Logical, internal, and physical reference behavior in CODASYL database systems
Authors: Wolfgang Effelsberg, Mary E. S. Loomis
Venue: ACM Transactions on Database Systems (TODS) (1984)

This work investigates one aspect of the performance of CODASYL database systems: the data reference behavior. We introduce a model of database traversals at three levels: the logical, internal, and physical levels. The mapping between the logical and internal levels is defined by the internal schema, whereas the mapping between the internal and the physical levels depends on cluster properties of the database. Our model explains the physical reference behavior for a given sequence of DML statements at the logical level. Software has been implemented to monitor references in two selected CODASYL DBMS applications. In a series of experiments the physical reference behavior was observed for varying internal schemas and cluster properties of the database. The measurements were limited to retrieval transactions, so that a variety of queries could be analyzed for the same well-known state of the database. Also, all databases were relatively small in order to allow fast reloading with varying internal schema parameters. In all cases, the database transactions showed less locality of reference than do programs under virtual memory operating systems; some databases showed no locality at all. No evidence of physical sequentiality was found. This suggests that standard page replacement strategies are not optimal for CODASYL database buffer management; instead, replacement decisions in a database buffer should be based on specific knowledge available from higher system layers.
Software development snapshots: A preliminary investigation
Authors: Laura Marie Leventhal
Venue: ACM SIGCHI Bulletin (1987)

A continuing challenge to investigators of human-computer interaction issues is the selection of an appropriate methodology. A particularly difficult aspect of methodology has been the choice of a proper test instrument. In the past, small programs have been favored by researchers because they were relatively easy to manage in a controlled experimental setting. Unfortunately the relationship between the cognitive demands of small programs and of real-world software systems remains unclear. Large programs as task elements bear more resemblence to software in realistic software development settings but tend to be difficult to control in an experimental setting (cf. Moher amp; Schneider, 1981).
On the power of one-way communication
Authors: Jik H. Chang, Oscar H. Ibarra, Anastasios Vergis
Venue: Journal of the ACM (JACM) (1988)

In this paper, a very simple model of parallel computation is considered, and the question of how restricting the flow of data to be one way compares with two-way flow is studied. It is shown that the one-way version is surprisingly very powerful in that it can solve problems that seemingly require two-way communication. Whether or not one-way communication is strictly weaker than two-way is an open problem, although the conjecture in this paper is in the positive. It is shown, however, that proving this conjecture is at least as hard as some well-known open problems in complexity theory.
Object-oriented programming in Smalltalk and ADA
Authors: Ed Seidewitz
Venue: ACM SIGPLAN Notices (1987)

Though Ada and Modula-2 are not object-oriented languages, an object-oriented viewpoint is crucial for effective use of their module facilities. It is therefore instructive to compare the capabilities of a modular language such as Ada with an archetypal object-oriented language such as Smalltalk. The comparison in this paper is in terms of the basic properties of encapsulation, inheritance and binding, with examples given in both languages. This comparison highlights the strengths and weaknesses of both types of languages from an object-oriented perspective. It also provides a basis for the application of experience from Smalltalk and other object-oriented languages to increasingly widely used modular languages such as Ada and Modula-2.
Universal closure operator for prolog
Authors: T Vasak
Venue: ACM SIGPLAN Notices (1986)

A powerful, second-order universal closure operator is proposed and its usefulness in constructing clear, efficient programs is demonstrated.
Direct least-squares fitting of algebraic surfaces
Authors: Vaughan Pratt
Venue: ACM SIGGRAPH Computer Graphics (1987)

In the course of developing a system for fitting smooth curves to camera input we have developed several direct (i.e. noniterative) methods for fitting a shape (line, circle, conic, cubic, plane, sphere, quadric, etc.) to a set of points, namely exact fit, simple fit, spherical fit, and blend fit. These methods are all dimension-independent, being just as suitable for 3D surfaces as for the 2D curves they were originally developed for.Exact fit generalizes to arbitrary shapes (in the sense of the term defined in this paper) the well-known determinant method for planar exact fit. Simple fit is a naive reduction of the general overconstrained case to the exact case. Spherical fit takes advantage of a special property of circles and spheres that permits robust fitting; no prior direct circle fitters have been as robust, and there have been no previous sphere fitters. Blend fit finds the best fit to a set of points of a useful generalization of Middleditch-Sears blending curves and surfaces, via a nonpolynomial generalization of planar fit.These methods all require (am+bn)n2 operations for fitting a surface of order n to m points, with a = 2 and b = 1/3 typically, except for spherical fit where b is larger due to the need to extract eigenvectors. All these methods save simple fit achieve a robustness previously attained by direct algorithms only for fitting planes. All admit incremental batched addition and deletion of points at cost an2 per point and bn3 per batch.
An operating system project using Concurrent Euclid
Authors: Dale H. Grit
Venue: ACM SIGCSE Bulletin (1988)

For the past four years, the senior level operating systems course at Colorado State University has been using a project to reinforce the lecture material. The project used is essentially the project described in Shaw[l], and is implemented using Concurrent Euclid. In this paper, we will: provide an overview of the project; introduce the Concurrent Euclid language, emphasizing those aspects that make it a good choice to support this project; provide some details concerning the implementation of the project; and discuss student reactions to the project.
Integrated Performance Models for Distributed Processing in Computer Communication Networks
Authors: Alexander Thomasian, Paul F. Bay
Venue: IEEE Transactions on Software Engineering (1985)

This paper deals with the analysis of large-scale closed queueing network (QN) models which are used for the performance analysis of computer communication networks (CCN's). The computer systems are interconnected by a wide-area network. Users accessing local/remote computers are affected by the contention (queueing delays) at the computer systems and the communication subnet. The computational cost of analyzing such models increases exponentially with the number of user classes (chains), even when the QN is tractable (product-form). In fact, the submodels of the integrated model are generally not product-form, e.g., due to blocking at computer systems (multiprogramming level constraints) and in the communication subnet (window flow control constraints). Two approximate solution methods are proposed in this paper to analyze the integrated QN model. Both methods use decomposition and iterative techniques to exploit the structure of the QN model such that computational cost is proportional to the number of chains. The accuracy of the solution methods is validated against each other and simulation. The model is used to study the effect that channel capacity assignments, window sizes for congestion control, and routing have on system performance.
Weighted bicubic spline interpolation to rapidly varying data
Authors: Thomas A. Foley
Venue: ACM Transactions on Graphics (TOG) (1987)

The weighted bicubic spline that is a C1 piecewise bicubic interpolant to three-dimensional gridded data is introduced. This is a generalization of the univariate weighted spline, developed by Salkauskas, in that a weighted minimization problem is solved. The minimization problem solved is a weighted version of the problem that the natural bicubic spline and Gordon's spline-blended interpolants minimize. The surface is represented as a piecewise bicubic Hermite interpolant whose derivatives are the solution of a linear system of equations. For computer-aided-design applications, the shape of the surface is controlled by weighting the variation over the individual patches, whereas many other shape-control methods weight the discrete data points. A method for selecting the weights is presented so that the weighted bicubic spline effectively solves the important and often difficult problem of interpolating rapidly varying data.
A Simulation Study of the CRAY X-MP Memory System
Authors: Tony Cheung, James E. Smith
Venue: IEEE Transactions on Computers (1986)

One of the significant differences between the CRAY X-MP and its predecessor, the CRAY-1S, is a considerably increased memory bandwidth for vector operations. Up to three vector streams in each of the two processors may be active simultaneously. These streams contend for memory banks as well as data paths. All memory conflicts are resolved dynamically by the memory system. This paper describes a simulation study of the CRAY X-MP interleaved memory system with attention focused on steady state performance for sequences of vector operations. Because it is more amenable to analysis, we first study the interaction of vector streams issued from a single processor. We identify the occurrence of linked conflicts, repeating sequences of conflicts between two or more vector streams that result in reduced steady state performance. Both worst case and average case performance measures are given. The discussion then turns to dual processor interactions. Finally, based on our simulations, possible modifications to the CRAY X-MP memory system are proposed and compared. These modifications are intended to eliminate or reduce the effects of linked conflicts.
Deans' electronic mail project
Authors: Susan Jenkins Saari
Venue: Proceedings of the 15th annual ACM SIGUCCS conference on User Services (1987)

Last fall at The Ohio State University, it was decided to train the president, provosts, deans, and directors of 26 college offices, and four remote campuses to use CMS Mail. This project was planned and designed Fall quarter, 1986, and put into operation in January, 1987. With the cooperation of several divisions of the Instruction and Research Computer Center (the academic computing center), and Telephone Services, and the deans' staff themselves, the entire process was successfully completed in just three months. This paper will discuss: Consulting with the various offices to discover what hardware was available to define what equipment and software were needed for electronic mail. Acquiring the needed hardware and software. Designing and planning the training program. Assembling and writing the training materials. Implementing the plan. Solving problems encountered along the way. Following up with all who were training. We estimate approximately 70-80% of the deans are actually using the electronic mail system regularly themselves. Most are very enthusiastic and already exploring what they can do next. Many of them had never used a personal computer. Personally, this project was one of the most challenging and satisfying programs with which I have been associated at Ohio State.
Scheduling difficulties of Ada in the hard real-time environment
Authors: Frank McCormick
Venue: ACM SIGAda Ada Letters (1987)

The tasking model in Ada suffers from several limitations which make scheduling strategies cumbersome for many embedded systems. This paper discusses the timing needs of one class of these systems and describes a plausible response to the problems.
Computation-tuple sequences and object histories
Authors: Seymour Ginsburg, Katsumi Tanaka
Venue: ACM Transactions on Database Systems (TODS) (1986)

A record-based, algebraically-oriented model is introduced for describing data for &ldquo;object histories&rdquo; (with computation), such as checking accounts, credit card accounts, taxes, schedules, and so on. The model consists of sequences of computation tuples defined by a computation-tuple sequence scheme (CSS). The CSS has three major features (in addition to input data): computation (involving previous computation tuples), &ldquo;uniform&rdquo; constraints (whose satisfaction by a computation-tuple sequence u implies satisfaction by every interval of u), and specific sequences with which to start the valid computation-tuple sequences. A special type of CSS, called &ldquo;local,&rdquo; is singled out for its relative simplicity in maintaining the validity of a computation-tuple sequence. A necessary and sufficient condition for a CSS to be equivalent to at least one local CSS is given. Finally, the notion of &ldquo;local bisimulatability&rdquo; is introduced for regarding two CSS as conveying the same information, and two results on local bisimulatability in connection with local CSS are established.
Synchronized Distributed Termination
Authors: Boleslaw Szymanski, Yuan Shi, Noah S. Prywes
Venue: IEEE Transactions on Software Engineering (1985)

An efficient decentralized algorithm for synchronized termination of a distributed computation is presented. It is assumed that distributed processes are connected via unidirectional channels into a strongly connected network, in which no central controller exists. The number of processes and the network configuration are not known a priori. The number of steps required to terminate distributed computation after all processes met their local termination conditions is proportional to the diameter D of the network (D + 1 steps).
Force-directed scheduling in automatic data path synthesis
Authors: P. G. Paulin, J. P. Knight
Venue: Proceedings of the 24th ACM/IEEE Design Automation Conference (1987)

The HAL system performs data path synthesis using a new scheduling algorithm that is part of an interdependent scheduling and allocation scheme. This scheme uses an estimate of the hardware allocation to guide and optimize the scheduling subtask. The allocation information includes the number, type, speed and cost of hardware modules as well as the associated multiplexer and interconnect costs. The iterative force-directed scheduling algorithm attempts to balance the distribution of operations that make use of the same hardware resources: Every feasible control step assignment is evaluated at each iteration, for all operations. The associated side-effects on all the predecessor and successor operations are taken into account. All the decisions are global. The algorithm has O(n8 complexity. We review and compare existing scheduling techniques. Moderate and difficult examples are used to illustrate the effectiveness of the approach.
&ldquo;Sometimes&rdquo; and &ldquo;not never&rdquo; revisited: on branching versus linear time temporal logic
Authors: E. Allen Emerson, Joseph Y. Halpern
Venue: Journal of the ACM (JACM) (1986)

The differences between and appropriateness of branching versus linear time temporal logic for reasoning about concurrent programs are studied. These issues have been previously considered by Lamport. To facilitate a careful examination of these issues, a language, CTL*, in which a universal or existential path quantifier can prefix an arbitrary linear time assertion, is defined. The expressive power of a number of sublanguages is then compared. CTL* is also related to the logics MPL of Abrahamson and PL of Harel, Kozen, and Parikh. The paper concludes with a comparison of the utility of branching and linear time temporal logics.
The integration of relational database algebra into APL
Authors: David Livingstone
Venue: ACM SIGAPL APL Quote Quad (1986)

A characteristic of Fourth Generation Languages is that they not only provide a high level of programmer productivity - as does APL - but also have a much wider area of applicability than conventional languages, or even APL. The aim of the project described here is to strengthen APL as a Fourth Generation Language by widening its scope though the addition of some database facilities, specifically data manipulation primitives. The primitives added are derived from Relational Database Algebra since this is based on the same philosophy as APL. As a relation is a special case of a generalized array, the algebra functions are generalized to handle n-dimensional arrays. The extra functions are not just add-ons or database facilities interfaced to APL, but primitives that maintain the unity of APL.
Approximate modelling of cognitive activity: towards an expert system design aid
Authors: Phil Barnard, Michael Wilson, Allan MacLean
Venue: ACM SIGCHI Bulletin (1987)

Constructs from theoretical psychology can be used to decompose the representational and processing resources of cognition. The decomposition supports &ldquo;cognitive task analysis&rdquo; through which user performance can be related to the functioning of resources. Such functional relationships have been formalised and embodied in an expert system. This builds approximate models which describe cognitive activity associated with the execution of dialogue tasks. Attributes of these &ldquo;cognitive task models&rdquo; can be used to predict likely properties of user performance.
This is IT: a metamodel of the software process
Authors: J Wileden
Venue: ACM SIGSOFT Software Engineering Notes (1986)

A systematic study of the software process will require a vocabulary in which various process models, methods and approaches can be described, compared and contrasted. This paper describes a meta-model that might provide such a vocabulary, illustrates how it might be used, and poses some example questions of the kind that such a meta-model should help in answering.
Heterogeneous computing environments: report on the ACM SIGOPS workshop on accommodating heterogeneity
Authors: David Notkin, Norman Hutchinson, Jan Sanislo
Venue: Communications of the ACM (1987)

The ACM SIGOPS Workshop on Accommodating Heterogeneity was conducted in December 1985 in Eastbound, Wash., as a forum for an international group of fifty researchers to discuss the technical issues surrounding heterogeneous computing environments.
The duality of database structures and design techniques
Authors: Mark L. Gillenson
Venue: Communications of the ACM (1987)

Attempting to pair database structures with database design techniques that seem incompatible yields some fascinating concepts about the world of database, including foreign keys and multiple relationships.