ppxscal/embedding_network huggingface dataset:
Standardizing the interface between applications and UIM's
Authors: P. Szekely
Venue: Proceedings of the 2nd annual ACM SIGGRAPH symposium on User interface software and technology (1989)

The user interface building blocks of any User Interface Management System (UIMS) have built-in assumptions about what information about application programs they need, and assumptions about how to get that information. The lack of a standard to represent this information leads to a proliferation of different assumptions by different building blocks, hampering changeability of the user interface and portability of applications to different sets of building blocks. This paper describes a formalism for specifying the information about applications needed by the user interface building blocks (i.e. the UIMS/Application interface) so that all building blocks share a common set of assumptions. The paper also describes a set of user interface building blocks specifically designed for these standard UIMS/Application interfaces. These building blocks can be used to produce a wide variety of user interfaces, and the interfaces can be changed without having to change the application program.
Multikey access methods based on term discrimination and signature clustering
Authors: J. W. Chang, J. H. Lee
Venue: ACM SIGIR Forum (1989)

In order to improve the two-level signature file method designed by Sacks-Davis et al. [20], we propose new multikey access methods based on term discrimination and signature clustering. By term discrimination, we create separate, efficient access methods for the terms frequently used in user queries. We in addition cluster similar signatures by means of these terms so that we may achieve good performance on retrieval. Meanwhile we provide the space-time analysis of the proposed methods and compare them with the two-level signature file method. We show that the proposed methods achieve 15-30% savings in retrieval time and require 3-9 % more storage overhead.
An analysis of server-based locking
Authors: B. L. Wolman
Venue: ACM SIGARCH Computer Architecture News (1989)

This paper discusses the performance implications of using server-based locking instead of shared memory locking in an input/output (IO) intensive benchmark. Uniprocessor and multiprocessor systems were investigated. Server-based locking was not a problem in uniprocessor runs or in multiprocessor runs that were processor limited. Server-based locking resulted in a significant degradation in throughput of IO limited multiprocessor runs.
Efficient and portable combined random number generators
Authors: P. L'Ecuyer
Venue: Communications of the ACM (1988)

In this paper we present an efficient way to combine two or more Multiplicative Linear Congruential Generators (MLCGs) and propose several new generators. The individual MLCGs, making up the proposed combined generators, satisfy stringent theoretical criteria for the quality of the sequence they produce (based on the Spectral Test) and are easy to implement in a portable way. The proposed simple combination method is new and produces a generator whose period is the least common multiple of the individual periods. Each proposed generator has been submitted to a comprehensive battery of statistical tests. We also describe portable implementations, using 16-bit or 32-bit integer arithmetic. The proposed generators have most of the beneficial properties of MLCGs. For example, each generator can be split into many independent generators and it is easy to skip a long subsequence of numbers without doing the work of generating them all.
A radix-2 FFT on connection machine
Authors: S. L. Johnsson, R. L. Krawitz, R. Frye, D. MacDonald
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

We describe a radix-2 FFT implementation on the Connection Machine. The FFT implementation pipelines successive FFT stages to make full use of the communication capability of the network interconnecting processors, when there are multiple elements assigned to each processor. Of particular interest in distributed memory architectures such as the Connection Machine is the allocation of twiddle factors to processors. We show that with a consecutive data allocation scheme and normal order input a decimation-in-time FFT results in a factor of log2N less storage for twiddle factors than a decimation-in-frequency FFT for N processors. Similarly, with consecutive storage and bit-reversed input a decimation-in-frequency FFT requires a factor of log2N less storage than a decimation-in-time FFT. The performance of the local FFT has a peak of about 3 Gflops/s. The &ldquo;global&rdquo; FFT has a peak performance of about 1.7 Gflops/s.
Using induction to design algorithms
Authors: Udi Manber
Venue: Communications of the ACM (1988)

An analogy between proving mathematical theorems and designing computer algorithms provides an elegant methodology for designing algorithms, explaining their behavior, and understanding their key ideas.
Performance Impacts of Look-Ahead Execution in the Conversation Scheme
Authors: K. H. Kim, S. M. Yang
Venue: IEEE Transactions on Computers (1989)

The look-ahead execution approach, which allows participant processes that exist early to exit from a conversation before other participants finish their conversation activities, is presented here as a fundamental approach to reducing the synchronization overhead. Queuing network models are developed for both the system operating under the basic conversation execution scheme and the system operating under the look-ahead execution scheme. Based on the models, various performance indicators such as the system throughput, the average number of processors idling inside a conversation due to the synchronization required, and the average time spent in conversation, are evaluated numerically for different application environments. The performance under the look-ahead execution scheme is compared with that under the basic conversation execution scheme. The results provide insights into the extent of benefits provided by the look-ahead execution approach.
The use of video in organizational studies
Authors: C. Allen
Venue: ACM SIGCHI Bulletin (1989)

In this paper I discuss the use of video in organizational studies, in particular, studies which are characterized by long term observation of a group or organization. These studies are different than many other types of investigation of human behavior in that they occur in uncontrolled circumstances. In the past I've used video for the study of designers at work on specific tasks, including graphic designers and typographers working for periods between an hour and six hours. In each of these cases, all of the activity occurred within the confines of a certain time and in a place where the video was continuously available and in use. In contrast, the work that occurs within an organization happens across a number of people and locations. Interaction happens not only in meeting rooms and at desks, but also in the hallways, at lunch, and in bathrooms, places where video may not always be appropriate or available.
Predicting and Estimating the Accuracy of a Subpixel Registration Algorithm
Authors: I. J. Cox, J. B. Kruskal, D. A. Wallach
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

It is shown that an efficient practical registration algorithm previously described by H.G. Barrow et al. (1977) can provide high-accuracy registration. Experiments with a quantized video image of a solid triangle yielded registration that was accurate to 3% of the interpixel spacing (i.e. accurate to 0.5 mils) in the x and y directions and 0.015 degrees in rotation. It may also be important to predict the accuracy in advance, to see whether specifications can be met and to estimate accuracy during registration, in order to control quality. The authors provide practical formulas for both purposes for two kinds of image point data: edge detection (ED) data and direct measurement (DM) data. In two experiments using ED data, the predicted, estimated, and observed accuracies are all in agreement. The prediction theory developed suggests five precautions to avoid loss of registration accuracy. Perhaps most important is Precaution c, the necessity of the ED case not to have a large fraction of the total segment length of the model aligned with the horizontal or vertical directions of the pixel grid. When the model consists largely of horizontal and vertical segments, a good way to observe this precaution is to tilt the pixel grid a few degrees away from perfect alignment, e.g. by tilting the video camera. A third experiment verifies that violating Precaution c can seriously degrade accuracy.
A geometric consistency theorem for a symbolic perturbation scheme
Authors: C. K. Yap
Venue: Proceedings of the fourth annual symposium on Computational geometry (1988)

In a previous paper, we introduced a generic solution to the problem of data degeneracy in geometric algorithms. The scheme is simple to use: algorithms qualifying under our requirements just have to use a prescribed blackbox for polynomial evaluation in order to achieve a symbolic perturbation of data. In this paper, we introduce the concept of an infinitesimal perturbation and show that our method is consistent relative to such perturbations.
A comparative study of two simple network file access models
Authors: H. Ghosh, S. Sreedhar
Venue: ACM SIGOPS Operating Systems Review (1990)

The authors have implemented two models for Remote File Access facilities in a network environment. This paper reviews the two implementations and compares their relative merits.
The Precision of 3-D Parameters in Correspondence-Based Techniques: The Case of Uniform Translational Motion in a Rigid Environment
Authors: M. A. Snyder
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

A general method of calculating the precision of environmental parameters which differs from conventional methods by finding analytical results, and which does so using only information in the image is discussed. This method called uncertainty-analysis, is applied to the case of first-order-error-based motion algorithms for determining environmental depth by matching corresponding points between two or more frames of a dynamic image sequence. How to calculate the uncertainty of in predicted values for the depth is shown, as well as how to calculate the search region for further instances of the point in subsequent frames, based only on information present in the image. The analysis is applied to a real image sequence with good results.
Interprocessor communication speed and performance in distributed-memory parallel processors
Authors: M. Annaratone, C. Pommerell, R. Rühl
Venue: ACM SIGARCH Computer Architecture News (1989)

We have simulated several numerical and non-numerical algorithms on five distributed-memory parallel processors (DMPPs). All five DMPPs have the same topology (a torus), and the same number of nodes. The architectures differ only in the communication speed between neighboring nodes, while the computation unit is kept unchanged. The goal of the paper is to quantify the effect that interprocessor communication speed and synchronization overhead have on the performance of the DMPPs. After introducing the rationale for this study and reviewing related work, we present and discuss the results of the simulations.
A novel approach to accurate timing verification using RTL descriptions
Authors: K. Roy, J. A. Abraham
Venue: Proceedings of the 26th ACM/IEEE Design Automation Conference (1989)

Timing verification is a critical part of VLSI circuit design. A new approach to timing verification using Register Transfer Level (RTL) descriptions is presented, which eliminates false paths that occur due to (i) redundancy, (ii) reconvergent fanout or (iii) control signal constraints, and generates a test for the critical paths. High level instructions of the circuit are used to test for any timing violations. An algorithm to identify a minimal set of instructions that tests the circuit for all timing errors in valid paths is proposed. Results are presented based on an implementation of the algorithm in LISP programming language on a TI Explorer machine.
Software Congestion, Mobile Servers, and the Hyperbolic Model
Authors: Michael L. Fontenot
Venue: IEEE Transactions on Software Engineering (1989)

The phenomenon of software congestion is examined. The term refers to situations in which the performance bottleneck of a system is an element of software, rather than a hardware device. Software congestion can occur in any system which contains one or more elements of software whose services may be simultaneously desired by multiple clients, but which can service only one client at a time. It is shown that the use of models which ignore software congestion can produce results that are completely irrelevant to actual system behavior. Furthermore, software congestion is frequently invisible to conventional performance measurement tools. A notational scheme, called mobile servers representation, is introduced for describing those systems in which software congestion may be important. An approximate analytical model, called the hyperbolic model, is developed for analyzing systems with software congestion.
The mesh superceded?
Authors: L. V. Kale
Venue: Proceedings of the 17th conference on ACM Annual Computer Science Conference (1989)

Two dimensional interconnection schemes have some inherent advantages because of their linear area and constant wire-lengths. The nearest-neighbor mesh is such a topology that has enjoyed a widespread acceptance. We investigate a family of bus-based topologies called the doble-lattice-meshes, and propose a variation to improve their properties. We show that the bus-based topologies perform better than the mesh for a variety of communicaion structures. In particular, when global communication is needed, they provide larger effective bandwidth, and when localized communication is permissible, they provide largest neighborhoods for a given communication capacity.
Developing analytic models based on simulation results
Authors: A. A. B. Prisker
Venue: Proceedings of the 21st conference on Winter simulation (1989)

This paper suggests that a simulation model provides results that lead to the development of analytic models. The analytic models can be used to uncover model relationships. Illustrations are given of simulation models that provide direction for analytic model building.
Pseudo-random generation from one-way functions
Authors: R. Impagliazzo, L. A. Levin, M. Luby
Venue: Proceedings of the twenty-first annual ACM symposium on Theory of computing (1989)

We show that the existence of one-way functions is necessary and sufficient for the existence of pseudo-random generators in the following sense. Let &fnof; be an easily computable function such that when x is chosen randomly: (1) from &fnof;(x) it is hard to recover an x1 with &fnof;(x1) = &fnof;(x) by a small circuit, or; (2) &fnof; has small degeneracy and from &fnof;(x) it is hard to recover x by a fast algorithm. From one-way functions of type (1) or (2) we show how to construct pseudo-random generators secure against small circuits or fast algorithms, respectively, and vice-versa. Previous results show how to construct pseudo-random generators from one-way functions that have special properties ([Blum, Micali 82], [Yao 82], [Levin 85], [Goldreich, Krawczyk, Luby 88]). We use the results of [Goldreich, Levin 89] in an essential way.
OLC: an on-line consulting system
Authors: T. J. Coppeto, B. L. Anderson, D. E. Geer, G. W. Treese
Venue: Proceedings of the 17th annual ACM SIGUCCS conference on User Services (1989)

Helping users learn the intricacies of UNIX1, particularly in a custom environment, is always a challenge. Helping thousands of users in an environment that is distributed both geographically and computationally is especially difficult. Project Athena has developed an &ldquo;On-Line Consulting&rdquo; system (OLC) that enables users to ask questions of consultants located &ldquo;somewhere on the network.&rdquo; OLC allows a staff on the order of twenty students to handle the questions and problems of over 8000 users on a network of more than 900 workstations. This paper describes the motives and design goals for OLC, its implementation, and some of the results of its three years of operation.
Analysis of database performance with dynamic locking
Authors: In Kyung Ryu, Alexander Thomasian
Venue: Journal of the ACM (JACM) (1990)

A detailed model of a transaction processing system with dynamic locking is developed and analyzed. Transaction classes are distinguished on the basis of the number of data items accessed and the access mode (read-only/update). The performance of the system is affected by transaction blocking and restarts, due to lock conflicts that do not or do cause deadlocks, respectively. The probability of these events is determined by the characteristics of transactions and the database access pattern. Hardware resource contention due to concurrent transaction processing is taken into account by specifying the throughput characteristic of the computer system for processing transactions when there is no data contention. A solution method based on decomposition is developed to analyze the system, and also used as the basis of an iterative scheme with reduced computational cost. The analysis to estimate the probability of lock conflicts and deadlocks is based on the mean number of locks held by transactions. These probabilities are used to derive the state transition probabilities for the Markov chain specifying the transitions among the system states. The decomposition solution method and the associated iterative scheme are shown to be more accurate than previously defined methods for dynamic locking through validation against simulation results. Several important conclusions regarding the behavior of dynamic locking systems are derived from parametric studies.
Proposal for a geometric algebra software package
Authors: T. F. Havel, B. Sturmfels, N. White
Venue: ACM SIGSAM Bulletin (1989)

A workshop on Symbolic Computations in Geometry held in October 1987 at the I.M.A. (University of Minnesota) dealt with the use of coordinate-free algebra in computational geometry, with a particular emphasis on Cayley-Grassmann algebra and bracket algebra [2]. Besides being mathematically elegant and computationally competative to the usual coordinate algebra, these methods are extremely useful tools for a variety of applications, e.g. in mathematical physics [5], biochemistry [3] or structural rigidity [8].
APL trivia
Authors: Edward Cherlin
Venue: ACM SIGAPL APL Quote Quad (1990)

APL derives great expressive power from seemingly trivial features, such as empty arrays, but there is still resistance to the implementation of the elementary trivial functions including left/stop &dashv; and right/pass &vdash;, which perform no calculations. This paper defines functional triviality; describes trivial functions and operators and their uses; discusses the mathematical basis of their expressive power; and defines new trivial functions and operators. It urges implementation of several of these functions as primitives for reasons of efficiency and expressiveness, and considers their efficient implementation via idiom recognition.
Comandos
Authors: R. Balter
Venue: ACM SIGSMALL/PC Notes (1989)

Pages are missing from the print and online versions of this paper
Cholesky downdating on a hypercube
Authors: C. S. Henkel, M. T. Heath, R. J. Plemmons
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

Least squares modifications associated with the addition or deletion of data often involve updating or downdating the Cholesky factor of the observation matrix. We describe and compare parallel implementations for the hypercube of three methods for down-dating the Cholesky factor: an orthogonal scheme, a hyperbolic scheme, and a hybrid scheme combining the first two. The computational complexities of these algorithms differ significantly, but the parallel implementations of all three have communication complexity similar to solving triangular systems. In computational tests on an Intel iPSC hypercube, the algorithms performed similarly, suggesting a preference for the orthogonal method based on stability considerations. The methods we describe can be adapted to the parallel computation of general orthogonal factorizations, but our discussion is motivated by applications in signal processing using windowed recursive least squares filtering for near real-time solutions.
A study of dissipation operators for the euler equations and a three- dimensional channel flow
Authors: P. Olsson, S. L. Johnsson
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

Explicit methods for the solution of fluid flow problems are of considerable interest in supercomputing. These methods parallelize well. The treatment of the boundaries is of particular interest both with respect to the numeric behavior of the solution, and the computational efficiency. We have solved the three-dimensional Euler equations for a twisted channel using second-order, centered difference operators, and a three stage Runge-Kutta method for the integration. Three different fourth-order dissipation operators were studied for numeric stabilization: one positive definite, [8], one positive semidefinite, [3], and one indefinite. The operators only differ in the treatment of the boundary. For computational efficiency all dissipation operators were designed with a constant bandwidth in matrix representation, with the bandwidth determined by the operator in the interior. The positive definite dissipation operator results in a significant growth in entropy close to the channel walls. The other operators maintain constant entropy. Several different implementations of the semidefinite operator obtained through factoring of the operator were also studied. We show the difference both in convergence rate and robustness for the different dissipation operators, and the factorizations of the operator due to Eriksson. For the simulations in this study one of the factorizations of the semidefinite operator required 70 - 90% of the number of iterations required by the positive definite operator. The indefinite operator was sensitive to perturbations in the inflow boundary conditions. The simulations were performed on a 8,192 processor Connection Machine system model CM-2. Full processor utilization was achieved, and a performance of 135 Mflops/s in single precision was obtained. A performance of 1.1 Gflops/s for a fully configured system with 65,536 processors was demonstrated.
Separating user interface and functionality using a frame based data model
Authors: J. Wielimaker, A. Anjewierden
Venue: Proceedings of the 2nd annual ACM SIGGRAPH symposium on User interface software and technology (1989)

The separation between user interface and functionality found in many screen editors is generalized to handle a data model based on frames and binary relations. This paper describes a User Interface Management System (UIMS) based on the data model. The UIMS is capable of maintaining different and simultaneous representations of the same application data objects. The functionality and user interface are implemented on top of a small object oriented programming system. This allows the UIMS to be simple and independent of the graphics software and hardware as well as the data representation used by the application programs.