ppxscal/embedding_network huggingface dataset:
Performance Analysis of Periodic and Concurrent Data Structure Maintenance Strategies for Network Servers
Authors: W. H. Bahaa-El-Din, F. B. Bastani, J.-F. Teng
Venue: IEEE Transactions on Software Engineering (1989)

Three strategies for designing servers and maintaining their data structures are discussed: incremental maintenance, periodic maintenance, and concurrent maintenance. The authors study periodic and concurrent maintenance strategies analytically in order to gain more insight into the behavior of servers using these strategies and determine when and how the maintenance should be performed. For periodic maintenance, it is shown that there is a value of the period which minimizes the average response time, and a formula to compute this value analytically is derived. For concurrent maintenance, a formula for its average response time and the condition under which concurrent maintenance would be preferable to periodic maintenance is derived. The authors have conducted a series of experiments to compare the performance of different maintenance strategies. For the system considered in the experiment, periodic maintenance yields the best average response time, whereas concurrent maintenance gives the least standard deviation and the smallest maximum response time.
Controlling deadlock in Ada
Authors: Gertrude Levine
Venue: ACM SIGAda Ada Letters (1989)

Ada's concurrency constructs provide synchronization and mutual exclusion mechanisms to control resource allocation. These constructs, if improperly used, can cause indefinite or infinite postponement of completion of service.Hembold and Luckham [3] and Cheng, Araki, and Ushijima [2] identify classes of these anomalies in order to aid in their detection. In this article we continue their discussion of the classification and control of these unbounded delays.
On Symmetric Error Correcting and all Unidirectional Error Detecting Codes
Authors: Sandip Kundu, Sudhakar M. Reddy
Venue: IEEE Transactions on Computers (1990)

The design of binary block codes that are capable of correcting up to t symmetric errors and detecting all unidirectional errors is discussed. A class of systematic t-symmetric-error-correcting/all-unidirectional-error-detecting (t-SyEC/AUED) codes are proposed. When t=0 the proposed codes become Berger codes. For t=1, the proposed codes are shown to be of asymptotically optimal order. Methods to construct nonsystematic t-SyEC/AUED codes for t=2 and 3 are also presented.
Finding all isolated solutions to polynomial systems using HOMPACK
Authors: Alexander P. Morgan, Andrew J. Sommese, Layne T. Watson
Venue: ACM Transactions on Mathematical Software (TOMS) (1989)

Although the theory of polynomial continuation has been established for over a decade (following the work of Garcia, Zangwill, and Drexler), it is difficult to solve polynomial systems using continuation in practice. Divergent paths (solutions at infinity), singular solutions, and extreme scaling of coefficients can create catastrophic numerical problems. Further, the large number of paths that typically arise can be discouraging. In this paper we summarize polynomial-solving homotopy continuation and report on the performance of three standard path-tracking algorithms (as implemented in HOMPACK) in solving three physical problems of varying degrees of difficulty. Our purpose is to provide useful information on solving polynomial systems, including specific guidelines for homotopy construction and parameter settings. The m-homogeneous strategy for constructing polynomial homotopies is outlined, along with more traditional approaches. Computational comparisons are included to illustrate and contrast the major HOMPACK options. The conclusions summarize our numerical experience and discuss areas for future research.
An undergraduate course in applied data communications
Authors: Larry J. Brumbaugh
Venue: Proceedings of the twentieth SIGCSE technical symposium on Computer science education (1989)

This paper describes a different type of data communications course than that presently offered in most computer science programs. Several justifications for such a course are provided.
Aspect, aspectual class, and the temporal structure of narrative
Authors: Alexander Nakhimovsky
Venue: Computational Linguistics (1988)

This paper consists of two parts. The first part discusses commonsense knowledge about events as manifested in language. Three kinds of knowledge are identified: compositional, durational, and aspectual. Compositional knowledge concerns internal structuring of events into preparatory, initial, main (the body), final, and resulting stages. Durational knowledge concerns durational relations between events and stages of the same event. Durational knowledge can be expressed as qualitative dependencies among the parameters of the event and as its time scale. The notion of time scale is introduced and related to shared cyclical events (time units).In discussing aspectual knowledge three notions are distinguished: aspect as a grammatical category of the verb, implemented by affixes, auxiliaries, and such; aspectual class, which is a characteristic of a lexical meaning; and the aspectual perspective of the sentence determined by the position of the Reference Time (RT) with respect to the event described by a finite clause. I argue that an aspectual classification of situations evolving in time should be based on such considerations as the kinds of resources they consume and the goals they achieve. A detailed classification of instantaneous and noninstantaneous events is developed.The second part of the paper discusses how this knowledge is employed in understanding extended narratives. Temporal discontinuities, in conjunction with other kinds of discontinuities identified in the paper, signal boundaries between discourse segments; within each segment, all three varieties of temporal knowledge help establish the temporal relations among narrated events.
Parallel vision techniques on the hypercube computer
Authors: A. H. Bond, D. Fashena
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

Parallel algorithms for programming low-level vision mechanisms on the JPL-Caltech hypercube are reported. These concern principally edge and region finding. 256x256 8bit images were used. We discuss the problem of programming a hypercube computer, and the Caltech approach to load balancing. We then discuss the distribution of images over the hypercube and the I/O problem for images. In edge finding, we programmed convolution using a separable kernel computational approach. This was tested with 5x5 and 32x32 masks. In region finding, we developed two different parallel histogram techniques. The first finds a global histogram for the image by a completely parallel technique. This method, which was developed from the Fox-Furmanski scalar product method, allows each histogram bucket to be computed by a separate processor, each processor regarding the hypercube as a different tree, and all buckets being computed in parallel by a complete interleaving of all communications required. Similarly the global histogram can then be distributed over the hypercube, so that all processors have the entire global histogram, by an completely parallel technique. The second histogramming method finds a spatially local histogram within each processor and then connects locally found regions together. Work in progress includes the application of a Hopfield neural net approach to region finding.
A Relational Calculus with Set Operators, Its Safety, and Equivalent Graphical Languages
Authors: G. Ozsoyoglu, H. Wang
Venue: IEEE Transactions on Software Engineering (1989)

The authors propose a relational calculus (RC/S) which uses set comparison and set manipulation operators to replace universal quantifiers and negations. It is argued that compared to the Codd relational calculus (RC), RC/S queries are easier to construct and comprehend. It is proved that the expressive power of RC is equivalent to the expressive power of RC/S, and algorithms for translating an RC query into an RC/S query and vice versa are given. A safe RC/S query is defined as one that has finite output and can be evaluated in finite time. Then a subset of RC/S queries, called RC/S* is defined, and it is proved that RC/S* is safe. RC/S* is compared to the existing largest safe subsets of RC, i.e. the evaluable formulas and the allowed formulas. Algorithms are given to transform any evaluable formula into an RC/S* query, and some RC/S* formulas that are not evaluable are given. RC/S* queries can be directly implemented using a graphical language similar to Query-by-Example (QBE). Two different graphical languages are described that are equivalent to the RC/S* in expressive power, and these languages are compared to QBE.
Designing keybindings to be easy to learn and resistant to forgetting even when the set of commands is large
Authors: N. Walker, J. R. Olson
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1988)

We formulated a set of rules for producing key-commands that are alternatives for activating commands with a mouse from a menu. Because software is getting increasingly complex, it was important that the rules cover a wide variety of commands. The rules combined verb-modifier-object order and mnemonic abbreviations for the words in each slot. Our keybindings were shown not only to cover a wide set, but to be far easier to learn than EMACs (a common keybinding set) and a more robust form with respect to negative interference from prior and post-learning of another set.
Speedup Versus Efficiency in Parallel Systems
Authors: D. L. Eager, J. Zahorjan, E. D. Lozowska
Venue: IEEE Transactions on Computers (1989)

The tradeoff between speedup and efficiency that is inherent to a software system is investigated. The extent to which this tradeoff is determined by the average parallelism of the software system, as contrasted with other, more detailed, characterizations, is shown. The extent to which both speedup and efficiency can simultaneously be poor is bound: it is shown that for any software system and any number of processors, the sum of the average processor utilization (i.e. efficiency) and the attained fraction of the maximum possible speedup must exceed one. Bounds are given on speedup and efficiency, and on the incremental benefit and cost of allocating additional processors. An explicit formulation, as well as bounds, are given for the location of the knee of the execution time-efficiency profile, where the benefit per unit cost is maximized.
Type checking records and variants in a natural extension of ML
Authors: D. Rémy
Venue: Proceedings of the 16th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

Strongly typed languages with records may have inclusion rules so that records with more fields can be used instead of records with less fields. But these rules lead to a global treatment of record types as a special case. We solve this problem by giving an ordinary status to records without any ad hoc assertions, replacing inclusion rules by extra information in record types. With this encoding ML naturally extends its polymorphism to records but any other host language will also transmit its power.
Reexamining intractability of tableau methods
Authors: N. V. Murray, E. Rosenthal
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

We consider the class of formulas on which the method of analytic tableaux was first shown to be intractable, and we show that with applications of the ordinary distributive law tableau methods admit linear time proofs for this class. We introduce a new class of formulas that are intractable for tableaux (even with the distributive law), and we demonstrate that path dissolution admits linear proofs of these formulas. Modifications of the tableau method are described that would render this class tractable. Since dissolution is linear on this class, these results demonstrate that dissolution cannot be p-simulated by the method of analytic tableau.
The Object-Oriented Structured Design Notation for Software Design Representation
Authors: Anthony I. Wasserman, Robert J. Muller, Peter A. Pircher
Venue: Computer (1990)

The development of a notation that supports key software structure concepts and design principles, is discussed. The notation should let designers represent modules, interfaces, hidden information, concurrency, message passing, invocation of operations and overall program structure in a comprehensive way. The authors examine three categories of approach to architectural design: object-oriented design, functional decomposition, and data structure design. They present their design notation, called object-oriented structured design (OOSD) which achieves the above-stated goal. They discuss classes in OOSD, its handling of asynchronous processes, and its design methods and rules. Automated support for OOSD is considered.
A transfer of skill between programming languages
Authors: J. C. Scholtz
Venue: ACM SIGCHI Bulletin (1989)

Experienced programmers transferring to a new programming language have a far easier time than the novice learning a first language; however, they still experience considerable difficulties. The objective in this study is to characterize the kinds of learning and transfer that take place in the early stages of using a new programming language and when difficulties develop. Thinking aloud protocols have been collected from novice, intermediate and expert programmers. Half of the subjects were observed transferring to a language similar to Pascal. The other half were observed while transferring to a language dissimilar to Pascal.
Refutational proofs of geometry theorems via characteristic set computation
Authors: D. Kapur, H. K. Wan
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

A refutational approach to geometry theorem proving using Ritt-Wu's algorithm for computing a characteristic set is discussed. A geometry problem is specified as a quantifier-free formula consisting of a finite set of hypotheses implying a conclusion, where each hypothesis is either a geometry relation or a subsidiary condition ruling out degenerate cases, and the conclusion is another geometry relation. The conclusion is negated, and each of the hypotheses (including the subsidiary conditions) and the negated conclusion is converted to a polynomial equation. Characteristic set computation is used for checking the inconsistency of a finite set of polynomial equations over an algebraic closed field. The method is contrasted with a related refutational method that used Buchberger's Gr&ouml;bner basis algorithm for the inconsistency check.
Requisite skills for new MIS hires
Authors: Hugh J. Watson, Dale Young, Shaila Miranda, Barry Robichaux, Ron Seerley
Venue: ACM SIGMIS Database (1990)

Rapidly changing technology makes the information systems (IS) field a highly dynamic one. IS professionals must possess the requisite skills to be successful in this environment. At an April 1988 meeting of The University of Georgia - MIS Industry Advisory Board, twenty Board members ranked the skills that new MIS graduates should have if they seek an entry-level position as a programmer, systems analyst, or end-user support professional. Separate ranked lists were generated through Collaborative Work System (CWS) software so that required skills could be compared across entry-level positions. The findings provide insights about the changing needs of industry and implications for academic programs in colleges and universities.
Ada in CS1
Authors: L. E. Winslow, J. E. Lang
Venue: Proceedings of the twentieth SIGCSE technical symposium on Computer science education (1989)

As the use of Ada in commercial programming increases, it becomes more important to make an attempt to introduce it into the curriculum as early as possible. We have taught CS1 successfully using Ada by strictly concentrating on a subset of the language and through the use of a student-oriented package which enables students to begin writing programs in Ada after one lecture. A laboratory of personal computers was found to be adequate for CS1 use and students were able to write up to 2 programs per week in the course.
How technology limits simulation methodology (panel)
Venue: Proceedings of the 21st conference on Winter simulation (1989)

In the past decade, a number of technological changes and creative developments have taken place to enhance the effectiveness of tools used in simulation modeling. These include developments in: computers, simulation modeling languages, user-interface design, graphical animation, and statistical analysis techniques. These changes and developments have had a direct impact on the practitioners of simulation. Compared to a decade ago (when simulation was largely batch oriented, required a high level of programming skills, and lacked graphics for model construction and/or animation) the simulation practitioner today has considerably more powerful and easier to use tools for simulation. As a result, simulation projects today are both less difficult to perform, and are more likely to be successful.
On Distributing JASMIN's Optimistic Multiversioning Page Manager
Authors: Ming-Yee Lai, Kevin Wilkinson, Vladimir Lanin
Venue: IEEE Transactions on Software Engineering (1989)

JASMIN is a functionally distributed database system running on multiple microcomputers that communicate with each other by message passing. The software modules in JASMIN can be cloned and distributed across computer boundaries. One important module is the intelligent store, a page manager that includes transaction-management facilities. It provides an optimistic, multiversioning concurrency control scheme. This scheme allows read-only transactions to run almost without conflict checking; this is important in some real-time database applications like telephone switching and routing services. The initial implementation of the intelligent store deals with centralized database only. Experiences in modifying the JASMIN intelligent store module to handle distributed databases are described. Design principles and system implementation techniques in the following areas are explored; process structure, data structures and synchronization on data structures. The process structure is aimed to provide high throughput and the data structures are designed to facilitate fast response time.
Approximate Analysis of Load Dependent General Queueing Networks
Authors: I. F. Akyildiz, Albrecht Sieber
Venue: IEEE Transactions on Software Engineering (1988)

A method for obtaining approximate solutions to load-dependent closed queueing networks containing general service-time distributions and first-come-first-served scheduling disciplines is presented. The technique demonstrated is an extension of the well-known method of R. Marie (1979). A formula for the conditional throughputs is derived. After each iteration a check is performed to guarantee that the results obtained are within a tolerance level epsilon . These iterations are repeated whenever invalid results are detected. On the average, the solutions obtained vary by less than 5% from their respective exact and simulation results.
Simulation graph duality: a world view transformation for simple queueing models
Authors: L. Schruben, E. Yucesan
Venue: Proceedings of the 21st conference on Winter simulation (1989)

Planar graphs play an important role in real world applications, partly due to the fact that some practical problems can be efficiently solved for planar graphs while they are intractable for general graphs. Simulation Graph Models of simple queueing systems are planar graphs. Their geometric duals can then be constructed. In the context of queueing models, this dualization process represents a transformation from the event scheduling to the activity scanning world view in discrete event simulation. The so-called primaldual pair of models provides an alternative but equivalent representation of these stochastic systems.
Object-oriented real-time language design: constructs for timing constraints
Authors: Yutaka Ishikawa, Hideyuki Tokuda
Venue: Proceedings of the European conference on object-oriented programming on Object-oriented programming systems, languages, and applications (1990)

We propose a new object-oriented programming language called RTC++ for programming real-time applications. RTC++ is an extension of C++ and its features are to specify i) a real-time object which is an active entity, ii) timing constraints in an operation as well as in statements, and iii) a periodic task with rigid timing constraints. In this paper, we first discuss real-time programming issues and what language support should be provided for building real-time applications. Then, the key features of RTC++ are described. Some programming examples are shown to demonstrate RTC++'s expressive power. A comparison to other programming languages are also discussed.
Personal computing: compuvision or teleputer
Authors: Larry Press
Venue: Communications of the ACM (1990)

Historically, the computer and communication industries have been separate, although both worked with electronically encoded information and shared similar technology. The regulations that kept computing and communication apart began to crumble in 1956 when the FCC ruled that Hush-a-Phone could attach equipment to the AT T network under special circumstances. In 1959 they opened a portion of the microwave spectrum, and the 1968 Carter-phone case allowed all kinds of equipment to be tied to the network. Today, IBM is in the communication business and AT T markets computers, but many feel that the distinction among computing, communication, news, and entertainment industries will blur or disappear. The question is, who will lead the charge&mdash;the computer companies, entertainment companies, toy companies, or phone companies? To put it another way, will the home computer swallow up the television set or will the television set become a computer in disguise? Not surprisingly, computer companies and entertainment companies have different answers to this question, and the debate was brought into focus by announcements at the Fifth Microsoft International CD-ROM Conference and Exposition. Let us look at the question of the home computer versus the smart TV and then come back to some of the other interesting announcements at the show and the current state of multimedia applications.
Documentation design based upon intuitive feature taxonomy and use logging
Authors: Hal Berghel, David Roach
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1990)

Although the quality of documentation of office automation software has increased significantly in the past few years, current offerings are not without problems. Those difficulties which have to do with the design and organization of the documentation are addressed in this paper. To illustrate, consider the following situations: 1) the command and control information which is commonly needed is either omitted or hard to find on the 'command card' or 'keyboard template' provided by the vendor, 2) the command or control information which we intuitively feel should be discussed in one section of the manual is actually located in an unrelated section, 3) the manual's table of contents does not seem to correspond well with the functional characteristics of the product, 4) the most appropriate command is not to be found in the manual's index, and 5) the 'help' facility frequently wastes rather than conserves time by providing the user with inappropriate alternatives. We maintain that these sorts of obstructions arise in many cases because insufficient attention has been given to an common sensical and intuitive analysis of the product's functionality as well as empirical use studies. We describe how these difficulties may be overcome by appeal to research results reported in the literature. Word processing software will be used to illustrate the technique.