ppxscal/embedding_network huggingface dataset:
Using GOMS for user interface design and evaluation: which technique?
Authors: Bonnie E. John, David E. Kieras
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (1996)

Since the seminal book, The Psychology of Human-Computer Interaction, the GOMS model has been one of the few widely known theoretical concepts in human-computer interaction. This concept has spawned much research to verify and extend the original work and has been used in real-world design and evaluation situations. This article synthesizes the previous work on GOMS to provide an integrated view of GOMS models and how they can be used in design. We briefly describe the major variants of GOMS that have matured sufficiently to be used in actual design. We then provide guidance to practitioners about which GOMS variant to use for different design situations. Finally, we present examples of the application of GOMS to practical design problems and then summarize the lessons learned.
Implementing real-time services in MINIX
Authors: Gabriel A. Wainer
Venue: ACM SIGOPS Operating Systems Review (1995)

In this work we present the results of a project devoted to provide programming facilities to develop hard real-time software. We have used MINIX operating system as a tool for our experience. We allow the programmer to define timing constraints for the tasks, letting to the Operating System the work of running these tasks in a timely fashion. In this way, we can improve productivity, security and costs in the system development cycle.
Multisplitting Preconditioners Based on Incomplete CholeskiFactorizations
Authors: R. Bru, C. Corral, A. Martinez, J. Mas
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

Let $Ax=b$ be a linear system where $A$ is a symmetric positive definite matrix. Preconditioners for the conjugate gradient method based on multisplittings obtained by incomplete Choleski factorizations of $A$ are studied. The validity of these preconditioners when $A$ is an $M$-matrix is proved and a parallel implementation is presented.
Algorithm 758: VLUGR2: a vectorizable adaptive-grid solver for PDEs in 2D
Authors: J. G. Blom, R. A. Trompert, J. G. Verwer
Venue: ACM Transactions on Mathematical Software (TOMS) (1996)

This article deals with an adaptive-grid finite-difference solver for time-dependent two-dimensional systems of partial differential equations. It describes the ANSI Fortran 77 code, VLUGR2, autovectorizable on the Cray Y-MP, that is based on this method. The robustness and the efficiency of the solver, both for vector and scalar processors, are illustrated by the application of the code to two example problems arising from a groundwater-flow model.
Fast simulation of rare events in queueing and reliability models
Authors: Philip Heidelberger
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (1995)

This paper surveys efficient techniques for estimating, via simulation, the probabilities of certain rare events in queueing and reliability models. The rare events of interest are long waiting times or buffer overflows in queueing systems, and system failure events in reliability models of highly dependable computing systems. The general approach to speeding up such simulations is to accelerate the occurrence of the rare events by using importance sampling. In importance sampling, the system is simulated using a new set of input probability distributions, and unbiased estimates are recovered by multiplying the simulation output by a likelihood ratio. Our focus is on describing asymptotically optimal importance sampling techniques. Using asymptotically optimal importance sampling, the number of samples required to get accurate estimates grows slowly compared to the rate at which the probability of the rare event approaches zero. In practice, this means that run lengths can be reduced by many orders of magnitude, compared to standard simulation. In certain cases, asymptotically optimal importance sampling results in estimates having bounded relative error. With bounded relative error, only a fixed number of samples are required to get accurate estimates, no matter how rare the event of interest is. The queueing systems studied include simple queues (e.g., GI/GI/1), Jackson networks, discrete time queues with multiple autocorrelated arrival processes that arise in the analysis of Asynchronous Transfer Mode communications switches, and tree structured networks of such switches. Both Markovian and non-Markovian reliability models are treated.
Scheduling Jobs with Temporal Distance Constraints
Authors: Ching-Chih Han, Kwei-Jay Lin, Jane W, .-S. Liu
Venue: SIAM Journal on Computing (1995)

The job scheduling problems for real-time jobs with temporal distance constraints (JSD) are presented. In JSD, the start times of two related jobs must be within a given distance. The general JSD problem is NP-hard. We define the multilevel unit-time JSD (MUJSD) problem for systems with $m$ chains of unit-time jobs in which neighboring jobs in each chain must be scheduled within $c$ time units. We present an $O(n^2)$-time algorithm, where $n$ is the total number of jobs in the system, and also an $O(m^2 c^2)$-time algorithm. Some other variations of the JSD problems are also investigated.
Manufacturing simulation consultant's forum
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Manufacturing simulation has been flourishing for a decade and as a result there are now a growing number of consultants who have considerable experience-much of it learned through painful trial and error. Unfortunately, this hard-won knowledge is not being proliferated because product, industry, geographic and competition barriers isolate manufacturing simulation consultants from each other. This forum allows consultants to exchange views and information on topical consulting issues.
The architecture of worknets
Authors: Matts Ahlsén, Peter Rosengren
Venue: ACM SIGOIS Bulletin (1995)

A current trend is to exploit information technology in support for virtual organisations. The research and practice focus on the development and evaluation of information and communication technologies intended to manage the business processes in such organisations, i.e., organisations characterised by geographical distribution and ability to change. In this article we discuss the "worknet" as one type of information system that can support the activities in such a virtual organisation. A worknet connects a number of participants for a limited amount of time in order to achieve some common objective, e.g., to establish a consortium or to form a coalition for some business objective.
The British Library's initiatives for access projects
Authors: Jonathan Purday
Venue: Communications of the ACM (1995)

The British Library holds over 18 million volumes and is one of the world's greatest treasure houses of written information from every age and culture. In 1993 it published its Strategic Objectives for the Year 2000, which made a commitment to providing maximum access to the collection using digital and networking technologies for onsite and remote users.
Transistor reordering for power minimization under delay constraint
Authors: S. C. Prasad, K. Roy
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (1996)

In this article we address the problem of optimization of VLSI circuits to minimize power consumption while meeting performance goals. We present a method of estimating power consumption of a basic or complex CMOS gate which takes the internal capacitances of the gate into account. This method is used to select an ordering of series-connected transistors found in CMOS gates to achieve lower power consumption. The method is very efficient when used by library-based design styles. We describe a multipass algorithm that makes use of transistor reordering to optimize performance and power consumption of circuits, has a linear time complexity per pass, and converges to a solution in a small number of passes. Transformations in addition to transistor reordering can be used by the algorithm. The algorithm has been benchmarked on several large examples and the results are presented.
Abstractions for Software Architecture and Tools to Support Them
Authors: Mary Shaw, Robert DeLine, Daniel V. Klein, Theodore L. Ross, David M. Young, Gregory Zelesnik
Venue: IEEE Transactions on Software Engineering (1995)

Architectures for software use rich abstractions and idioms to describe system components, the nature of interactions among the components, and the patterns that guide the composition of components into systems. These abstractions are higher level than the elements usually supported by programming languages and tools. They capture packaging and interaction issues as well as computational functionality. Well-established (if informal) patterns guide architectural design of systems. We sketch a model for defining architectures and present an implementation of the basic level of that model. Our purpose is to support the abstractions used in practice by software designers. The implementation provides a testbed for experiments with a variety of system construction mechanisms. It distinguishes among different types of components and different ways these components can interact. It supports abstract interactions such as data flow and scheduling on the same footing as simple procedure call. It can express and check appropriate compatibility restrictions and configuration constraints. It accepts existing code as components, incurring no runtime overhead after initialization. It allows easy incorporation of specifications and associated analysis tools developed elsewhere. The implementation provides a base for extending the notation and validating the model.
On the Symmetric and Unsymmetric Solution Set of Interval Systems
Authors: Gotz Alefeld, Gunter Mayer
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

We consider the solution set $S$ of real linear systems $Ax = b$ with the $n \times n$ coefficient matrix $A$ varying between a lower bound $\underline{A}$ and an upper bound $\overline{A}$, and with $b$ similarly varying between $\underline{b},\ \overline{b}$. First we list some properties on the shape of $S$ if all matrices $A$ are nonsingular. Then we restrict $A$ to be nonsingular and symmetric deriving a complete description for the boundary of the corresponding symmetric solution set $S_{\rm sym}$ in the $2 \times 2$ case. Finally we derive a new criterion for the feasibility of the Cholesky method with which bounds for $S_{\rm sym}$ can be found.
Compiler technology for parallel scientific computation
Authors: Can Özturan, Balaram Sinharoy, Boleslaw K. Szymanski
Venue: Scientific Programming (1994)

There is a need for compiler technology that, given the source program, will generate efficient parallel codes for different architectures with minimal user involvement. Parallel computation is becoming indispensable in solving large-scale problems in science and engineering. Yet, the use of parallel computation is limited by the high costs of developing the needed software. To overcome this difficulty we advocate a comprehensive approach to the development of scalable architecture-independent software for scientific computation based on our experience with equational programming language (EPL). Our approach is based on a program decomposition, parallel code synthesis, and run-time support for parallel scientific computation. The program decomposition is guided by the source program annotations provided by the user. The synthesis of parallel code is based on configurations that describe the overall computation as a set of interacting components. Run-time support is provided by the compiler-generated code that redistributes computation and data during object program execution. The generated parallel code is optimized using techniques of data alignment, operator placement, wavefront determination, and memory optimization. In this article we discuss annotations, configurations, parallel code generation, and run-time support suitable for parallel programs written in the functional parallel programming language EPL and in Fortran.
How to create a successful failure
Authors: Robert N. Charette
Venue: Communications of the ACM (1995)

Many people enjoy working on software projects that wing their way towards failure. After all, troubled projects offer so much more in the way of excitement and advantages than those that boringly plod their way to success. For instance, projects in turmoil provide numerous ways to look good. You can make both employer and customer deliriously happy, become a hero, and gain a promotion merely for getting something, anything, delivered on time&mdash;while on a smoothly running project, it's expected! Even if you don't make the delivery, you can still appear heroic and get promoted. But if you screw things up, who knows? Then there is the increased job security. Projects in turmoil usually go on far past their original deadlines, as customers are loath to cancel and lose their investment. Your company benefits too, as it gets paid much more than if the project was merely successful.
Finite Element Approximations of Compensator Design for Analytic Generators with Fully Unbounded Controls/Observations
Authors: I. Lasiecka
Venue: SIAM Journal on Control and Optimization (1995)

An approximation theory leading to a design of a finite- dimensional compensator for control systems generated by analytic semigroups is presented. The novelty of this paper with respect to other results available in the literature is threefold: (i) it treats fully unbounded control/observation operators; (ii) it does not require compactness property of the underlined generator (an assumption that is often violated in practice); and (iii) the design of a finite-dimensional compensator is based on finite element approximation of the original model rather than on modal (eigenfunctions) approximations which, in turn, require the a priori knowledge of the eigenvalues for the system. Applications of the theory to heat equations and plate equations are provided.
Error repair in shift-reduce parsers
Authors: Bruce J. McKenzie, Corey Yeatman, Lorraine de Vere
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1995)

Local error repair of strings during CFG parsing requires the insertion and deletion of symbols in the region of a syntax error to produce a string that is error free. Rather than precalculating tables at parser generation time to assist in finding such repairs, this article shows how such repairs can be found during shift-reduce parsing by using the parsing tables themselves. This results in a substantial space saving over methods that require precalculated tables. Furthermore, the article shows how the method can be integrated with lookahead to avoid finding repairs that immediately result in further syntax errors. The article presents the results of experiments on a version of the LALR(1)-based parser generator Bison to which the algorithm was added.
Diffracting trees
Authors: Nir Shavit, Asaph Zemach
Venue: ACM Transactions on Computer Systems (TOCS) (1996)

Shared counters are among the most basic coordination structures in multiprocessor conputation, with applications ranging from barrier synchronization to concurrent-data-structure design. This article introduces diffracting trees, novel data structures for share counting and load balancing in a distributed/parallel environment. Empirical evidence, collected on a simulated distributed shared-memory machine and several simulated message-passing architectures, shows that diffracting trees scale better and are more robust than both combining trees and counting networks, currently the most effective known methods for implementing concurrent counters in software. The use of a randomized coordination method together with a combinatorial data structure overcomes the resiliency drawbacks of combining trees. Our simulations show that to handle the same load, diffracting trees and counting networks should have a similar width w, yet the depth of a diffracting tree is O(log w), whereas counting networks have depth O(log2 w). Diffracting trees have already been used to implement highly efficient producer/consumer queues, and we believe diffraction will prove to be an effective alternative paradigm to combining and queue-locking in the design of many concurrent data structures.
Simulating construction operations of precast-concrete parking structures
Authors: Liang Y. Liu
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Modern construction operations involve many different resources such as labor, equipment, and materials. The interactions among these resources can be realistically modeled and analyzed using discrete-event simulation. During construction planning, it is necessary to model and simulate construction operations and develop a work plan that minimizes idleness, eliminates bottlenecks, increases productivity, and reduces costs. Among the various applications in the construction industry, discrete-event simulation has been successfully used in modeling the construction of precast-concrete parking structures. The paper presents the application of discrete-event simulation to model and analyze the erection process of a precast concrete parking structure. Simulation is conducted by using a graphical discrete-event simulation system named COOPS. Construction equipment, labor, concrete members, erection times, and operating strategy are modeled and simulated to investigate the productivity, resource utilization, and unit costs.
A framework for providing consistent and recoverable agent-based access to heterogeneous mobile databases
Authors: Evaggelia Pitoura, Bharat Bhargava
Venue: ACM SIGMOD Record (1995)

Information applications are increasingly required to be distributed among numerous remote sites through both wireless and wired links. Traditional models of distributed computing are inadequate to overcome the communication barrier this generates and to support the development of complex applications. In this paper, we advocate an approach based on agents. Agents are software modules that encapsulate data and code, cooperate to solve complicated tasks, and run at remote sites with minimum interaction with the user. We define an agent-based framework for accessing mobile heterogeneous databases. We then investigate concurrency control and recovery issues and outline possible solutions. Agent-based computing advances database transaction and control flow management concepts and remote programming techniques.
Procedure exlining: a transformation for improved system and behavioral synthesis
Authors: Frank Vahid
Venue: Proceedings of the 8th international symposium on System synthesis (1995)

Abstract: We present techniques for solving the inverse problem of procedure inlining, namely the problem of replacing sequences of statements with procedure calls. Two techniques are provided, one for finding redundant sequences of statements that can be replaced by calls to one procedure, and another for dividing a large set of statements into several procedures, where each procedure performs a distinct computation. Such procedure exlining can transform a behavioral specification, originally written for readability, into a specification that can be implemented efficiently, because procedures can greatly improve the results of synthesis tools. We demonstrate the usefulness of the techniques on several examples. We have implemented the procedure exlining technique as part of a VHDL transformation tool.
Algorithm 753: TENPACK: a LAPACK-based library for the computer manipulation of tensor products
Authors: Paul E. Buis, Wayne R. Dyksen
Venue: ACM Transactions on Mathematical Software (TOMS) (1996)

This article presents the interface of an implementation of methods to manipulate equations of this form A1&otimes;&cdots;&otimes;Am where the Ai are matrices. The methods described are independent of m. The code is based on LAPACK and the BLAS and supports virtually all of the matrix formats supported by those packages. Timings of the implementation on several machines are also given.
Grey group relation and their general problems (I)
Authors: Xiaozhong Li, Kaiquan Shi
Venue: ACM SIGICE Bulletin (1995)

In this paper, we define grey set relation and grey group relation. Their general problems are studied. Some basic results are obtained.
A hybrid approach of the standard clock method and event scheduling approach for general discrete event simulation
Authors: Chun-Hung Chen
Venue: Proceedings of the 27th conference on Winter simulation (1995)

The standard clock (SC) method is an efficient approach for discrete event simulation. Its basic ideas are quite different from traditional approaches. SC has neither an event list nor event lifetimes. However, its applicability is limited to exponential distributions and a class of non-exponential distributions. In this paper we provide an effective approach to extend SC to all general distributions, while preserving the efficiency advantage of SC. Numerical testing shows that our approach can effectively accomplish this goal.
An Extension of Geman and Reynolds' Approach to Constrained Restoration and the Recovery of Discontinuities
Authors: Merrilee Hum, Christopher Jennison
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

Geman and Reynolds [7] present an approach to linear image restoration which provides for recovery of horizontal and vertical gray-level discontinuities from blurred and noisy observations. We extend their model and parameter selection method to include diagonal discontinuities. A hazard of this modeling approach is identified and addressed. We also comment on the truncated Gibbs sampler suggested in the paper [7].
A new search algorithm for discrete stochastic optimization
Authors: Mahmoud H. Alrefaei, Sigrún Andradóttir
Venue: Proceedings of the 27th conference on Winter simulation (1995)

We present a new method for finding a global optimal solution to a discrete stochastic optimization problem. This method resembles the simulated annealing method for discrete deterministic optimization. However, in our method the annealing schedule (the cooling temperature) is kept fixed, and the mechanism for estimating the optimal solution is different from that used in the original simulated annealing method. We state a convergence result that shows that our method converges almost surely to a global optimal solution under mild conditions. We also present empirical results that illustrate the performance of the proposed approach on a simple example.