ppxscal/embedding_network huggingface dataset:
BVE: a wafer-scale engine for differential equation computation
Authors: J. G. Delgado-Frias, D. M. Green
Venue: Proceedings of the 2nd international conference on Supercomputing (1988)

With the advent of specialized VLSI and WSI hardware components the finite difference algorithms for solving differential equations become more attractive. This paper presents a novel computer architecture dedicated to compute boundary value problems. Improvement in speed and reliability can be obtained by means of WSI technology; however, a fault/defect tolerant scheme must be designed. Here we present a time redundancy approach which uses all the available computational resources; this is there is no spare or idle processors. This special purpose WSI parallel architecture runs as a loosely coupled MIMD (multi-instruction multi-data streams) machine and may execute more than 100 million instructions per second. The main features of this boundary value engine (BVE) are: 1) local communication -connections are limited to nearest neighbor; 2) cell regularity -all processors, memories and buses are identical; and 3) fault-tolerance -faulty modules are discarded by means of a novel time redundancy approach. As the feature size continues to shrink, the architecture can easily be extended to accommodate more computational cells.
Extending the radiosity method to include specularly reflecting and translucent materials
Authors: Holly E. Rushmeier, Kenneth E. Torrance
Venue: ACM Transactions on Graphics (TOG) (1990)

An extension of the radiosity method is presented that rigorously accounts for the presence of a small number of specularly reflecting surfaces in an otherwise diffuse scene, and for the presence of a small number of specular or ideal diffuse transmitters. The relationship between the extended method and earlier radiosity and ray-tracing methods is outlined. It is shown that all three methods are based on the same general equation of radiative transfer. A simple superposition of the earlier radiosity and ray-tracing methods in order to account for specular behavior is shown to be physically inconsistent, as the methods are based on different assumptions. Specular behavior is correctly included in the present method. The extended radiosity method and example images are presented.
The quality of expertise: implications of expert-novice differences for knowledge acquisition
Authors: Marianne LaFrance
Venue: Issue 108 (April 1989) (1989)

Recognizing that the knowledge of experts is qualitatively and not just quantitatively different from the knowledge of novices is an important pre-requisite to conducting effective knowledge acquisition. This article reviews the current cognitive research on expertise and proposes seven ways in which the knowledge of experts is different from the knowledge of novices, including such aspects as underlying schema, goal-orientation, practical focus, categorical chunking, cognitive complexity, automaticity of expert problem solving, and finally, the episodic nature of expert memory. The paper concludes with an outline of several implications that follow from this research including showing why knowledge acquisition will remain problematic without knowledge of experts' knowledge, as well as making a number of specific suggestions for those who need to elicit expert knowledge for knowledge-based systems.
Logic fault simulation on a vector hypercube multiprocessor
Authors: F. Ozguner, C. Aykanat, O. Khalid
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

Fault simulation is the process of simulating the response of a logic circuit to input patterns in the presence of all possible single faults and is an essential part of test generation for VLSI circuits. Parallelization of the deductive and parallel simulation methods, on a hypercube multiprocessor and vectorization of the parallel simulation method are described. Experimental results are presented.
Integrating network optimization capabilities into a high-level modeling language
Authors: Stavros A. Zenios
Venue: ACM Transactions on Mathematical Software (TOMS) (1990)

Research in network optimization has reached the stage where large-scale problems-linear or non-linear, pure or generalized-are solved very efficiently with minimal computing resources. Representing such problems for solution on the computer, however, remains a rather cumbersome task. Taking advantage of developments in high-level modeling languages, we design and implement integrated systems to facilitate the representation and solution of network problems. Such systems integrate the flexibility and robustness of modeling languages with the efficiency of network optimizers. We describe two alternative modes for this integration, which can be achieved for linear and nonlinear problems alike. The use of the resulting systems is demonstrated with the solution of large-scale problems from diverse applications and with the implementation of network decomposition algorithms.
Unsupervised Optimal Fuzzy Clustering
Authors: I. Gath, A. B. Gev
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

This study reports on a method for carrying out fuzzy classification without a priori assumptions on the number of clusters in the data set. Assessment of cluster validity is based on performance measures using hypervolume and density criteria. An algorithm is derived from a combination of the fuzzy K-means algorithm and fuzzy maximum-likelihood estimation. The unsupervised fuzzy partition-optimal number of classes algorithm performs well in situations of large variability of cluster shapes, densities, and number of data points in each cluster. The algorithm was tested on different classes of simulated data, and on a real data set derived from sleep EEG signal.
Host/target approach to embedded system development is becoming obsolete
Authors: J. E. Tardy
Venue: ACM SIGSOFT Software Engineering Notes (1988)

For many years, the primary mode of development for real-time embedded software has been the "host/target" approach. In this approach, the software for the application is developed on one computer system to be executed on another. The increased memory and speed of embedded hardware has now reached a point where these systems are capable of supporting both their real-time applications and the software engineering environments for their development. This has made the acceptance of the higher risk and complexity inherent to the host/target approach an undesirable strategy.The shift back to self-targetted development for embedded software will have important consequences in the future of Software Engineering Environments. It also heralds the emergence of a new type of computer system: The General Purpose Embedded Computer.
Experimental Results on Subgoal Reordering
Authors: X. Nie, David A. Plaisted
Venue: IEEE Transactions on Computers (1990)

The effect on the performance of a goal-oriented theorem power is studied on subgoal re-ordering using some simple synthetic heuristics. It is shown that subgoal reordering using these simple heuristics has a considerable impact on the performance of the prover on a large set of test problems. Some heuristics even provide equally good, and often better, performance as to the hand ordering of the input clauses. The merit of the approach seems to be that the syntactic aspect of theorem proving is considered. This approach is simple in form and cheap in its evaluation, and often provides good heuristics.
Design of the opportunistic garbage collector
Authors: P. R. Wilson, T. G. Moher
Venue: ACM SIGPLAN Notices (1989)

The Opportunistic Garbage Collector (OGC) is a generational garbage collector for stock hardware and operating systems. While incorporating important features of previous systems, the OGC includes several innovations. A new bucket brigade heap organization supports advancement thresholds between one and two scavenges, using only two or three spaces per generation, and without requiring per-object counts. Opportunistic scavenging decouples scavenging from the filling of available memory, in order to hide potentially disruptive scavenge pauses and improve efficiency. Card marking efficiently records which small areas of the heap may contain pointers into younger generations, and is supported by a refinement of the crossing map technique, to enable scanning of arbitrary cards.
VisiCLANG&mdash;a visible compiler for CLANG
Authors: D. Resler
Venue: ACM SIGPLAN Notices (1990)

This paper describes a visible compiler for the CLANG language. VisiCLANG shows on-screen, in various text windows, all aspects of the CLANG compiler as it compiles and executes a user's program. This allows someone who is learning the techniques of compiler construction to see the inner workings of a simple recursive-descent compiler.
Implementation strategies for continuations
Authors: Will Clinger, Anne Hartheimer, Eric Ost
Venue: Proceedings of the 1988 ACM conference on LISP and functional programming (1988)

Scheme and Smalltalk continuations may have unlimited extent. This means that a purely stack-based implementation of continuations, as suffices for most languages, is inadequate. Several implementation strategies have been described in the literature. Determining which is best requires knowledge of the kinds of programs that will commonly be run. Danvy, for example, has conjectured that continuation captures occur in clusters. That is, the same continuation, once captured, is likely to be captured again. As evidence, Danvy cited the use of continuations in a research setting. We report that Danvy's conjecture is somewhat true in the commercial setting of MacScheme+Toolsmith&trade;, which provides tools for developing Macintosh user interfaces in Scheme. These include an interrupt-driven event system and multitasking, both implemented by liberal use of continuations. We describe several implementation strategies for continuations and compare four of them using benchmarks. We conclude that the most popular strategy may have a slight edge when continuations are not used at all, but that other strategies perform better when continuations are used and Danvy's conjecture holds.
Improving aviation accident research through the use of video
Authors: Herbert B. Armstrong
Venue: ACM SIGCHI Bulletin (1989)

The investigation and analysis of aviation accidents is a critical aspect of aviation safety and a major tool for aviation system improvement. The National Transportation Safety Board is charged with the responsibility of determining the probable cause of aviation accidents, identifying contributing factors, and making recommendations for changes to equipment or procedures as a result of their investigations. The intent is to identify what went wrong and prevent its recurrence -- to learn from the errors of others and, thus, save lives and property.
Knowledge elicitation during dynamic scene description
Authors: J. Malec
Venue: Issue 108 (April 1989) (1989)

Analyzing and describing the dynamic scenes of an autonomous intelligent vehicle is a problem tackled in many recent research projects. However, the suggested (or realized) solutions do not introduce any methodology - they are direct implications of current state of the art in sensor technology and applications of sensor fusion techniques.
Computing the order of a solvablepermutation group
Authors: Charles C. Sims
Venue: Journal of Symbolic Computation (1990)

This paper presents a new algorithm for determining the order of a solvable permutationgroup from a set of generators. During the computation, a base and strong generating set and a polycyclic generating sequence are also obtained.
Moving off center
Authors: C. Collins, W. Miller, F. Blake
Venue: Proceedings of the 17th annual ACM SIGUCCS conference on User Services (1989)

A computer center as a concept is in many ways in anachronism. Gone are the days when legions of students and faculty would march diligently to the building on campus that was the sole source of power for their research or instruction. In the building were housed not only machines but friendly people and wizards who could help researchers meet their goals. For most computing on campus, there no longer is a center&mdash;physically, intellectually, or spiritually&mdash;that encases computing and its myriad support functions. In some cases, the castle is in a state of decay. What has risen in its stead are tens or hundreds or thousand of cottage industries&mdash;small-to medium-sized computer centers in faculty offices, student labs, and departmental offices. In some instances, they have appointed their own king or queen, but often the support system for that person is very weak. The revolution is complete. The days of massively central computer centers and services are gone. Yet what mechanisms exist to 1) help build strong cottage centers and 2) help create strong support systems between the cottage centers and with the remaining central computing services?
A general two-pass method integrating specular and diffuse reflection
Authors: F. Sillion, C. Puech
Venue: Proceedings of the 16th annual conference on Computer graphics and interactive techniques (1989)

We analyse some recent approaches to the global illumination problem by introducing the corresponding reflection operators, and we demonstrate the advantages of a two-pass method. A generalization of the system introduced by Wallace et al. at Siggraph '87 to integrate diffuse as well as specular effects is presented. It is based on the calculation of extended form-factors, which allows arbitrary geometries to be used in the scene description, as well as refraction effects. We also present a new sampling method for the calculation of form-factors, which is an alternative to the hemi-cube technique introduced by Cohen and Greenberg for radiosity calculations. This method is particularly well suited to the extended form-factors calculation. The problem of interactive display of the picture being created is also addressed by using hardware-assisted projections and image composition to recreate a complete specular view of the scene.
Spritely NFS: experiments with cache-consistency protocols
Authors: V. Srinivasan, J. Mogul
Venue: Proceedings of the twelfth ACM symposium on Operating systems principles (1989)

File caching is essential to good performance in a distributed system, especially as processor speeds and memory sizes continue to improve rapidly while disk latencies do not. Stateless-server systems, such as NFS, cannot properly manage client file caches. Stateful systems, such as Sprite, can use explicit cache consistency protocols to improve both cache consistency and overall performance. By modifying NFS to use the Sprite cache consistency protocols, we isolate the effects of the consistency mechanism from the other features of Sprite. We find dramatic improvements on some, although not all, benchmarks, suggesting that an explicit cache consistency protocol is necessary for both correctness and good performance.
Comparison of dataflow control techniques in distributed data-intensive systems
Authors: W. Alexander, G. Copeland
Venue: ACM SIGMETRICS Performance Evaluation Review (1988)

In dataflow architectures, each dataflow node (i.e., operation) is typically executed on a single physical node. We are concerned with distributed data-intensive systems, in which each base (i.e., persistent) set of data has been declustered over many physical nodes to achieve load balancing. Because of large base set size, each operation is executed where the base set resides, and intermediate results are transferred between physical nodes. In such systems, each dataflow node is typically executed on many physical nodes. Furthermore, because computations are data-dependent, we cannot know until run time which subset of the physical nodes containing a particular base set will be involved in a given dataflow node. This uncertainty affects program loading, task activation and termination, and data transfer among the nodes. In this paper we focus on the problem of how a dataflow node in such an environment knows when it has received data from all the physical nodes from which it is ever going to receive. We call this the dataflow control problem. The interesting part of the problem is trying to achieve correctness efficiently. We propose three solutions to this problem, and compare them quantitatively by the metrics of total message traffic, message system throughput and data transfer response time.
Managing knowledge about information system evolution
Authors: Matthias Jarke, Thomas Rose
Venue: ACM SIGMOD Record (1988)

This paper describes the design and initial prototype implementation of a knowledge base management system (KBMS) for controlling database software development and maintenance. The KBMS employs a version of the conceptual modelling language CML to represent knowledge about the tool-aided development process of an information system from requirements analysis to conceptual design to implementation, together with the relationship of these system components to the real-world environment in which the information system is intended to function. A decision-centered documentation methodology facilitates communication across time and among multiple developers (and possibly users), thus enabling improved maintenance support.
A hybrid hypercube algorithm for the symmetric tridiagonal eigenvalue problem
Authors: J. A. Jackson, L. M. Liebrock, L. R. Ziegler
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

Two versions of an algorithm for finding the eigenvalues of symmetric, tridiagonal matrices are described. They are based on the use of the Sturm sequences and the bisection algorithm. The algorithms were implemented on the FPS T-Series. Some speedup factor results are presented.
Specification of Spatial Integrity Constraints in Pictorial Databases
Authors: A. Pizano, A. Klinger, A. Cardenas
Venue: Computer (1989)

A model and a language for specifying spatial integrity constraints in pictorial databases are presented. Spatial integrity constraints are assertions about the correct behavior of database systems that specify acceptable database states and state transitions. They also serve as restrictions on positions occupied by objects in a picture. The language presented primarily uses pictures to specify constraints. The constraint pictures depict unacceptable database states. A data model provides the basic semantics for picture interpretation.
Integrating security in a large distributed system
Authors: M. Satyanarayanan
Venue: ACM Transactions on Computer Systems (TOCS) (1989)

Andrew is a distributed computing environment that is a synthesis of the personal computing and timesharing paradigms. When mature, it is expected to encompass over 5,000 workstations spanning the Carnegie Mellon University campus. This paper examines the security issues that arise in such an environment and describes the mechanisms that have been developed to address them. These mechanisms include the logical and physical separation of servers and clients, support for secure communication at the remote procedure call level, a distributed authentication service, a file-protection scheme that combines access lists with UNIX mode bits, and the use of encryption as a basic building block. The paper also discusses the assumptions underlying security in Andrew and analyzes the vulnerability of the system. Usage experience reveals that resource control, particularly of workstation CPU cycles, is more important than originally anticipated and that the mechanisms available to address this issue are rudimentary.
Program development for a systolic array
Authors: Bernd Bruegge
Venue: Proceedings of the ACM/SIGPLAN conference on Parallel programming: experience with applications, languages and systems (1988)

The primary objective of the Warp programming environment (WPE) is to simplify the use of Warp, a high-performance programmable linear systolic array connected to a general-purpose workstation host. WPE permits the development of distributed applications that access Warp either locally from the host or remotely from a large number of workstations connected to a local area network. Its audience includes the user who calls routines from a library, the programmer who develops new algorithms for Warp, as well as the implementor who writes support software. Since the linear arrangement of the cells in the array restricts direct input and output with the host to the boundary cells, a source language debugger is important for program development on Warp. This paper presents the Warp debugger and its relation to the other components of the Warp programming environment.
Verifiable secret sharing and multiparty protocols with honest majority
Authors: T. Rabin, M. Ben-Or
Venue: Proceedings of the twenty-first annual ACM symposium on Theory of computing (1989)

Under the assumption that each participant can broadcast a message to all other participants and that each pair of participants can communicate secretly, we present a verifiable secret sharing protocol, and show that any multiparty protocol, or game with incomplete information, can be achieved if a majority of the players are honest. The secrecy achieved is unconditional and does not rely on any assumption about computational intractability. Applications of these results to Byzantine Agreement are also presented. Underlying our results is a new tool of Information Checking which provides authentication without cryptographic assumptions and may have wide applications elsewhere.
Profiles in mass storage: a tale of two systems
Authors: B. Collins, D. Kitts, M. Devaney
Venue: Proceedings of the 1988 ACM/IEEE conference on Supercomputing (1988)

The Los Alamos Common File System (CFS) and the NCAR Mass Storage System (MSS) are file storage and file management systems that serve heterogeneous computing networks of supercomputers, general purpose computers, scientific workstations and personal computers. This paper details philosophical, implementation and performance aspects of the two mass storage systems. Areas covered include the computing environment, the user interface, storage strategies and file movement strategies.
Measurements of Ada Overhead in OSI-Style Communications Systems
Authors: N. R. Howes, A. C. Weaver
Venue: IEEE Transactions on Software Engineering (1989)

A discussion is given on whether the Ada model of concurrency is suitable for implementing the seven-layer OSI reference model. Using the communications model introduced by R.J.A. Buhr (1984), they determine the overhead introduced by Ada when the model is implemented on two single-processor machines, a VAX 11/785 and a Rational 1000. The authors then calculate a lower bound on expected message delay. A novel model using server tasks is proposed and shown to have better performance. The authors investigate performance on an eight-processor Sequent Model 821 and a 14-processor Encore Multimax 320 by implementing the Buhr model, the server task model and a third model which abandons the Ada rendezvous in favor of procedure calls. They determine the Ada overhead per message as a function of the number of processors and calculate lower bounds on expected message delay attributable to Ada overhead for all three communications models.