ppxscal/embedding_network huggingface dataset:
Performance evaluation for an ocean general circulation model: vectorization andmultitasking
Authors: P. Andrich, G. Madec
Venue: Proceedings of the 2nd international conference on Supercomputing (1988)

General circulation models are used to study the dynamics of the global ocean. Based on the Navier-Stokes equations, with the hypothesis of incompressibility and the Boussinesq approximation (the so-called primitive equations), and using a large number of gridpoints, their speed performance is a major bottle-neck. For these models parallelism is a promising technique to get reasonable completion times. Here a method of multitasking an ocean general circulation model is presented which divides the three-dimensional domain into horizontally or vertically independent slabs, depending on which term of the equations, and distributes the computations to different processors. In addition, at each time step an elliptic equation is solved in parallel. Synchronizations are performed between the processors by calls to a unique subroutine which establishes a barrier synchronization. An application is performed on a CRAY-2 showing a speed-up on the order of 3.5 using 4 processors, for a problem of the order of 100x100 horizontal gridpoints and 16 vertical levels, which is a common discretization for oceanic models. The vectorization is still efficient as the ratio of no-vector/vector is of the order of 13.
Fault tolerance under UNIX
Authors: Anita Borg, Wolfgang Blau, Wolfgang Graetsch, Ferdinand Herrmann, Wolfgang Oberle
Venue: ACM Transactions on Computer Systems (TOCS) (1989)

The initial design for a distributed, fault-tolerant version of UNIX based on three-way atomic message transmission was presented in an earlier paper [3]. The implementation effort then moved from Auragen Systems1 to Nixdorf Computer where it was completed. This paper describes the working system, now known as the TARGON/32. The original design left open questions in at least two areas: fault tolerance for server processes and recovery after a crash were briefly and inaccurately sketched, rebackup after recovery was not discussed at all. The fundamental design involving three-way message transmission has remained unchanged. However, in addition to important changes in the implementation, server backup has been redesigned and is now more consistent with that of normal user processes. Recovery and rebackup have been completed in a less centralized and thus more efficient manner than previously envisioned. In this paper we review important aspects of the original design and note how the implementation differs from our original ideas. We then focus on the backup and recovery for server processes and the changes and additions in the design and implementation of recovery and rebackup.
The semantics of program dependence
Authors: Robert Cartwright, Mattias Felleisen
Venue: ACM SIGPLAN Notices (1989)

Optimizing and parallelizing compilers for procedural languages rely on various forms of program dependence graphs (pdgs) to express the essential control and data dependencies among atomic program operations. In this paper, we provide a semantic justification for this practice by deriving two different forms of program dependence graph &mdash; the output pdg and the def-order pdg&mdash;and their semantic definitions from non-strict generalizations of the denotational semantics of the programming language. In the process, we demonstrate that both the output pdg and the def-order pdg (with minor technical modifications) are conventional data-flow programs. In addition, we show that the semantics of the def-order pdg dominates the semantics of the output pdg and that both of these semantics dominate&mdash;rather than preserve&mdash;the semantics of sequential execution.
An algorithm for optimal lambda calculus reduction
Authors: John Lamping
Venue: Proceedings of the 17th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

We present an algorithm for lambda expression reduction that avoids any copying that could later cause duplication of work. It is optimal in the sense defined by L&eacute;vy. The basis of the algorithm is a graphical representation of the kinds of commonality that can arise from substitutions; the idea can be adapted to represent other kinds of expressions besides lambda expressions. The algorithm is also well suited to parallel implementations, consisting of a fixed set of local graph rewrite rules.
Rendering CSG models with a ZZ-buffer
Authors: David Salesin, Jorge Stolfi
Venue: Proceedings of the 17th annual conference on Computer graphics and interactive techniques (1990)

The ZZ-buffer is a simple acceleration scheme for ray tracing that can be applied to a wide variety of scenes, including those with small features, textured and transparent surfaces, shadows and penumbrae, and depth-of-field effects. In this paper, we describe how the ZZ-buffer algorithm can be adapted to the rendering of scenes defined by constructive solid geometry operations.
Garp: a graphical/textual language for concurrent programming
Authors: S. M. Kaplan, S. K. Goering
Venue: Proceedings of the 1988 ACM SIGPLAN workshop on Object-based concurrent programming (1988)

Concurrent systems in which the number of processes and their interconnections can change dynamically suffer from the problem of ensuring that process interconnections are correctly maintained at all times. We propose a hybrid solution to this problem in which processes are described textually, but interconnections are described graphically using a graph grammar to constrain the legal sets of processes and interconnections that the system may evolve. This paper discusses GARP, a hybrid graphical/textual concurrent programming language that acts as a testbed for our ideas, and illustrates its use with an example.
Methodology for comparative selection of interactive database interface types
Authors: L. K. Cristiano
Venue: ACM SIGCHI Bulletin (1989)

On-line database applications are becoming the most common new software tasks. Their use is becoming increasingly popular in all areas of information management. In many environments these on-line applications are made available to a large, diverse user population. The majority of these users do not have training in database or software areas. For this reason, the interface between the user and the database is vital. It serves to protect the integrity of the database by governing user access and it provides an understandable medium through which the untrained user can obtain or update the desired data.The appropriateness of the interface can affect the success or failure of the database application. The wrong type of interface can result in inefficient data access and a reluctance on the part of users to utilize the tool. Most interactive database interfaces fall into two general categories, menu-driven or command- driven. These two interface types are dissimilar in appearance, usage, and often in performance. This article will provide a set of generalized criteria to assist the database manager or designer in selecting which interface type is better suited for a given application. The same criteria can also be used by managers in selecting a commercial database product for purchase. Factors such as the logical structure of the data, characteristics of the user community, and cost are considered. A worksheet is provided to allow for a quantitative analysis of the criteria in order to establish a foundation for the decision-making process.
Feedback queues with preemption-distance priorities
Authors: M. Paterok, O. Fischer, L. Opta
Venue: Proceedings of the 1989 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1989)

The method of moments is used to derive exact analytical solutions for an open priority queueing system with preemption-distance priorities and feedback. Customers enter from outside in a Poisson stream. They can feed back for several times, changing priorities and service demands in an arbitrary manner. During feedback they can fork and branch according to user-defined probabilities. The service demands of the different classes are pairwise independent and can be arbitrarily distributed. A customer who has been interrupted resumes his service from the point where he was interrupted (preemptive resume). A system of linear equations is to be solved to obtain the mean sojourn times of each customer class in the system.
FCFS: a novel scheduling policy for tightly-coupled parallel computer systems
Authors: J. Place
Venue: Proceedings of the 17th conference on ACM Annual Computer Science Conference (1989)

Tightly-coupled parallel computer systems are available from several vendors. The mechanism for process scheduling employed by virtually all of these systems is preemptive by job priority. This scheme for process scheduling consumes significant processor resources and can result in significant processor contention for the scheduling data structure. In this paper we show that it is possible to reduce the number of job priorities, and at the same time reduce the administrative overhead on the system, without significantly increasing job wait time. Also we show, by four simulation studies, that non-preemptive scheduling mechanisms are just as effective as preemptive techniques when coupled with time slice control and multiprogramming limits. Thus simplified scheduling techniques that require little overhead to prevent processor contention may be employed in a tightly coupled parallel environment without sacrificing either mean response time or the &sgr; of response time.
A practical approach to semantic configuration management
Authors: M. Moriconi
Venue: Proceedings of the ACM SIGSOFT '89 third symposium on Software testing, analysis, and verification (1989)

A configuration management (CM) tool is supposed to build a consistent software system following incremental changes to the system. The notion of consistency usually is purely syntactic, having to do with the sorts of properties analyzed by compilers. Semantic consistency traditionally has been studied in the field of formal methods and has been considered an impractical goal for CM. Although the semantic CM problem is undecidable, it is possible to obtain a structural approximation of the semantic effects of a change in a finite number of steps. Our approximation technique is formalized in logic and is based on information-theoretic properties of programs. The method in its present form applies to many but not all software systems, and it is programming-language independent. To the best of our knowledge, the semantic CM problem has not been formalized previously in nonsemantic terms, and we believe that our simplified formulation offers the potential for considerably more powerful debugging and configuration management tools.
Performance modelling of a HSLAN slotted ring protocol
Authors: M. Zafirovic-Vukotic, I. G. M. M. Niemegeers
Venue: ACM SIGMETRICS Performance Evaluation Review (1988)

The slotted ring protocol which is evaluated in this paper is suitable for use at very large transmission rates. In terms of modelling it is a multiple cyclic server system. A few approximative analytical models of this protocol are presented and evaluated vs the simulation in this paper. The cyclic server model shows to be the most accurate and usable over a wide range of parameters. A performance analysis based on this model is presented.
Imprecise schema: a rationale for relations with embedded subrelations
Authors: Howard M. Dreizen, Shi-Kuo Chang
Venue: ACM Transactions on Database Systems (TODS) (1989)

Exceptional conditions are anomalous data which meet the intent of a schema but not the schema definition, represent a small proportion of the database extension, and may become known only after the schema is in use. Admission of exceptional conditions is argued to suggest a representation that locally stretches the schema definition by use of relations with embedded subrelations. Attempted normalization of these relations to 1NF does not yield the static schema typically associated with such transformations. A class of relations, termed Exceptional Condition Nested Form (ECNF), is defined which allows the necessary representation of exceptional conditions while containing sufficient restrictions to prevent arbitrary and chaotic inclusion of embedded subrelations. Queries on a subset of exceptional conditions, the exceptional constraints, are provided an interpretation via an algorithm that transforms ECNF relations into 1NF relations containing two types of null values. Extensions of relational algebraic operators, suitable for interactive query navigation, are defined for use with ECNF relations containing all forms of exceptional conditions.
Hyperflow
Authors: D. DeForest, A. Faustini, R. Lee
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications: Architecture, software, computer systems, and general issues - Volume 1 (1988)

In this paper we show how a model of parallel computation called Eduction (tagged demand-driven dataflow) can be implemented on a hypercube. The resulting implementation is called Hyperflow. In addition we will deal with the issue of programmability of the hypercube through use of the declarative language Lucid.
Generalized E-filter and Its Application to Edge Detection
Authors: N. Saito, M. A. Cunningham
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

The E-filter is a homomorphic filter proposed by D.J.H. Moore and D.J. Parker (1973) which differentiates the small and large amplitude components of a signal. A description is given of a generalization of the E-filter to include a control parameter. Selective tuning of this parameter causes the behavior of the E-filter to range from linear to highly nonlinear. It is found that the E-filter can be simply implemented and has several properties which make it attractive for use in edge detection problems. The superiority of the E-filter to sale-space filtering for edge detection in one-dimensional systems is shown.
Laser beam testing of finished integrated circuits
Authors: Auvert Geoffroy
Venue: Microelectronic Engineering (1988)

Today testing an integrated circuit needs the use of a one micron size laser probe. The reflected part of a laser beam focussed on a VLSI circuit allows us to form with a high magnification microscope, the image of an integrated circuit. The OBIC technique allows to directly observe an electricaly active junction at the silicon substrate level of a circuit. These two visualisation techniques are completed with mapping techniques which allows us to locate sensitive areas in VLSI circuits. Localisation of marginal voltage defects and latch-up sensitive areas are the two main examples.
An Adaptive Algorithm to Ensure Differential Service in a Token-Ring Network
Authors: Myungwhan Choi, C. M. Krishna
Venue: IEEE Transactions on Computers (1990)

A distributed and adaptive token-passing algorithm that can be used to maintain the values of a designated performance parameter (e.g. mean waiting time) at the hosts of a token-ring network at a prescribed ratio is presented. The algorithm is simple to implement. The authors demonstrate its application in keeping the mean waiting times at the various hosts in a prespecified ratio, in maintaining a designated throughput differential between different classes of customer, and in integrating voice and two classes of data on a token ring.
An assumption-based localization technique for switching system
Authors: Shin-ichi Wada, Yoshiyuki Koseki
Venue: Proceedings of the 2nd international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1989)

In troubleshooting large scale equipments, fault localization interferences involve indeterminateness and they might lead to erroneous conclusions. To realize indeterminate inferences, an assumption-based fault localization technique has been developed. The technique allows inferences based on indeterminate assumptions. When inconsistencies are discovered, assumption are revised. The technique also enables flexible diagnosis control, such as reasoning based on anticipated test results without actually carrying out the tests. When the anticipated results become doubtful, it activates the omitted tests. The paper describes the technique and an outline of the troubleshooting expert system for electronic switching systems based on the technique.
Design of the Mneme persistent object store
Authors: J. Eliot B. Moss
Venue: ACM Transactions on Information Systems (TOIS) (1990)

The Mneme project is an investigation of techniques for integrating programming language and database features to provide better support for cooperative, information-intensive tasks such as computer-aided software engineering. The project strategy is to implement efficient, distributed, persistent programming languages. We report here on the Mneme persistent object store, a fundamental component of the project, discussing its design and initial prototype. Mneme stores objects in a simple and general format, preserving object identity and object interrelationships. Specific goals for the store include portability, extensibility (especially with respect to object management policies), and performance. The model of memory that the store aims at is a single, cooperatively-shared heap, distributed across a collection of networked computers. The initial prototype is intended mainly to explore performance issues and to support object-oriented persistent programming languages. We include performance measurements from the prototype as well as more qualitative results.
Using registers to optimize cross-domain call performance
Authors: Paul A. Karger
Venue: ACM SIGARCH Computer Architecture News (1989)

This paper describes a new technique to improve the performance of cross-domain calls and returns in a capability-based computer system. Using register optimization information obtained from the compiler, a trusted linker can minimize the number of registers that must be saved, restored, or cleared when changing from one protection domain to another. The size of the performance gain depends on the level of trust between the calling and called protection domains. The paper presents alternate implementations for an extended VAX architecture and for a RISC architecture and reports performance measurements done on a re-microprogrammed VAX-11/730 processor.
SLD: a folk acronym?
Authors: G. A. Ringwood
Venue: ACM SIGPLAN Notices (1989)

Delving into the archives for the meaning of SLD reveals that the name is ill chosen. Furthermore, empiric evidence shows that the significance of the letters is entering the realms folklore. As clear logical thinking about a subject is impeded if the vocabulary is misleading or confused this note is intended to bring this matter to light before many more generations of logic programmers proliferate misconceptions. Clear logical thinking is of even greater import for a subject that purports to be about logic.
An empirical study of computer capacity planning in Japan
Authors: S. F. Lam
Venue: Communications of the ACM (1988)

Capacity planners in Japan rely heavily on intuitive and judgmental approaches in their computer capacity planning functions, even more so than their U.S. counterparts, according to the following survey. The emphasis in large Japanese firms on job rotations, lifetime employment, and extensive social and informal interaction among employees helps contribute to the effectiveness of these judgmental methods.
A Test to Determine the Multivariate Normality of a Data Set
Authors: S. P. Smith, A. K. Jain
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

A test is described for multivariate normality that is useful in pattern recognition. The test is based on the Friedman-Rafsky (1979) multivariate extension of the Wald-Wolfowitz runs test. The test data are combined with a multivariate swarm of points following the normal distribution generated with mean vector and covariance matrix estimated from the test data. The minimal spanning tree of this resultant ensemble of points is computed and the count of the interpopulation edges in the minimal spanning tree is used as a test statistic. The simulation studied both the null case of the test and one simple deviation from normality. Two conclusions are made from this study. First, the test can be conservatively applied by using the asymptotic normality of the test statistic, even for small sample sizes. Second, the power of the test appears reasonable, especially in high dimensions. Monte Carlo experiments were performed to determine if the test is reliable in high dimensions with moderate sample size. The method is compared to other such tests available in the literature.
PC-based software: the future is now
Authors: Jeretta Horn Nord, G. Daryl Nord, Richard A. Aukerman
Venue: ACM SIGSMALL/PC Notes (1989)

Since the conception of the electronic computer, software technology has evolved through four stages or generations: machine, assembler, high-level or third generation (3GL), and fourth generation languages (4GL). The fourth generation of software is non-procedural in nature; that is, 4GL's employ a small set of powerful commands that tell the computer what to do, as opposed to procedural languages that tell the computer how to do it. Fourth generation languages may also include procedural capabilities which can be combined with non-procedural code. With the focus shifting from how to what, 4GL's allow nonprofessional programmers to get results, are typically user-friendly, and may of them include a database management system. In addition, less code is required using fourth generation software; therefore: debugging is reduced, it is easier to understand and maintain another's code, and results can be obtained in less time. As the gap between people and computers decreases through the use of fourth generation software, productivity is and will continue to be greatly enhanced. This concept, which is often referred to as end-user computing, is gaining momentum with the advent of PC-based microcomputer 4GL's.
Limitations on the portability of real time Ada programs
Authors: T. Griest, m. Bender
Venue: Proceedings of the conference on Tri-Ada '89: Ada technology in context: application, development, and deployment (1989)

This paper describes areas of the Ada language where transportability is restricted by the fact that implementation choices are allowed. Transportability guidelines have been developed previously for Ada [2,3,10], but have taken the approach that only features of the language which are guaranteed to be supported by all implementations should be used. The &ldquo;common intersection&rdquo; approach rules out use of many features that were included in Ada because they are required for real-time applications. This paper addresses the transportability of real-time Ada programs from a realistic point of view. Specifically, time-critical applications are of little use being transportable if they execute too slowly on all available implementations; and reasonable people will not wish to transport an application to architectures and/or compilation systems that do not support the requirements of the application. A practical approach to managing these difficulties is presented as a set of transportability guidelines. These guidelines are intended to improve the transportability of programs which must rely on language features that are implementation dependent.