ppxscal/embedding_network huggingface dataset:
Comparisons of concurrent tracking on various hypercubes
Authors: C. F. Baillie, T. D. Gottschalk, A. Kolawa
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications: Architecture, software, computer systems, and general issues - Volume 1 (1988)

The concurrent multi-target tracking code is ported to and run on the Intel iPSC and Ncube hypercubes. The (minor) difficulties in this porting are noted. The biggest single problem in running the tracking program is found to be the rather limited node memories on the iPSC and Ncube machines. Timing results for the analysis of a sample threat on the iPSC, Ncube and Mark-III hypercubes are presented. The relative performances of the various machines are found to be consistent with prior expectations. A fairly large sample scenario is investigated using 4 through 8-dimensional Ncube configurations, and variations of Ncube performance for differing levels of CrOS porting are examined. Initial results of running the tracking program on the BBN Butterfly are also presented.
How do experienced information lens users use rules?
Authors: W. E. Mackay, T. W. Malone, K. Crowston, R. Rao, D. Rosenblitt, S. K. Card
Venue: ACM SIGCHI Bulletin (1989)

The Information Lens provides electronic mail users with the ability to write rules that automatically sort, select, and filter their messages. This paper describes preliminary results from an eighteen-month investigation of the use of this system at a corporate test site. We report the experiences of 13 voluntary users who have each had at least three months experience with the most recent version of the system. We found that:People without significant computer experience are able to create and use rules effectively.Useful rules can be created based on the fields present in all messages (e.g., searching for distribution lists or one's own name in the address fields or for character strings in the subject field), even without any special message templates. People use rules both to prioritize messages before reading them and to sort messages into folders for storage after reading them.People use delete rules primarily to filter out messages from low-priority distribution lists, not to delete personal messages to themselves.
Improving a human-computer dialogue
Authors: Rolf Molich, Jakob Nielsen
Venue: Communications of the ACM (1990)

A survey of seventy-seven highly motivated industrial designers and programmers indicates that the identification of specific, potential problems in a human-computer dialogue design is difficult.
Integer arithmetic
Authors: H. K. Hodge
Venue: ACM SIGSMALL/PC Notes (1989)

The work which forms the basis for this article had its genesis in The Theory of Thermodynamics, by J. R. Waldram (Cambridge University Press, 1985). Mr. Waldram, rather than building upon the differential laws of thermodynamics (entropy, energy, etc.), states a fundamental relationship from which he will construct said laws:[EQUATION]This represents the number of ways in which Q identical quanta can be distributed amoung N oscillators; that is, the number of states in which such a collection can be.
Debugging concurrent programs
Authors: Charles E. McDowell, David P. Helmbold
Venue: ACM Computing Surveys (CSUR) (1989)

The main problems associated with debugging concurrent programs are increased complexity, the "probe effect," nonrepeatability, and the lack of a synchronized global clock. The probe effect refers to the fact that any attempt to observe the behavior of a distributed system may change the behavior of that system. For some parallel programs, different executions with the same data will result in different results even without any attempt to observe the behavior. Even when the behavior can be observed, in many systems the lack of a synchronized global clock makes the results of the observation difficult to interpret. This paper discusses these and other problems related to debugging concurrent programs and presents a survey of current techniques used in debugging concurrent programs. Systems using three general techniques are described: traditional or breakpoint style debuggers, event monitoring systems, and static analysis systems. In addition, techniques for limiting, organizing, and displaying a large amount of data produced by the debugging systems are discussed.
A finite presentation theorem for approximating logic programs
Authors: Nevin Heintze, Joxan Jaffar
Venue: Proceedings of the 17th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

The notion of Cartesian closure on a set of unifiers has been used to define approximations of the least models of logic programs. Such approximations, often called types, are not known to be recursive. In this paper, we use Cartesian closure to define a similar, but more accurate, approximation. The main result proves that our approximation is not only recursive, but that it can be finitely represented in the form of a cyclic term graph. This explicit representation can be used as a starting point for logic program analyzers.
A quasi-distributed architecture for database management systems
Authors: A. L. Tharp, E. A. Middleton
Venue: Proceedings of the 17th conference on ACM Annual Computer Science Conference (1989)

This paper describes a new architecture for database management systems. This quasi-distributed architecture is a compromise between the traditional centralized architecture and the more recent distributed architecture. As such it provides benefits over both architectures but also has limitations when compared with them. The quasi-distributed architecture is made possible from recent advances in computer technology: it uses economical workstations to place more of the processing at remote sites, and it uses the increased storage capacity of CD-ROMs, WORMs and hard disks to store more data closer to where it will be used. The paper gives an overview of the quasi-distributed architecture and discusses its advantages, disadvantages, and limitations. Although it is not a general purpose architecture, it is suitable for certain situations.
Multicast routing in datagram internetworks and extended LANs
Authors: Stephen E. Deering, David R. Cheriton
Venue: ACM Transactions on Computer Systems (TOCS) (1990)

Multicasting, the transmission of a packet to a group of hosts, is an important service for improving the efficiency and robustness of distributed systems and applications. Although multicast capability is available and widely used in local area networks, when those LANs are interconnected by store-and-forward routers, the multicast service is usually not offered across the resulting internetwork. To address this limitation, we specify extensions to two common internetwork routing algorithms&mdash;distance-vector routing and link-state routing&mdash;to support low-delay datagram multicasting beyond a single LAN. We also describe modifications to the single-spanning-tree routing algorithm commonly used by link-layer bridges, to reduce the costs of multicasting in large extended LANs. Finally, we discuss how the use of multicast scope control and hierarchical multicast routing allows the multicast service to scale up to large internetworks.
A thinning algorithm by contour generation
Authors: Paul Kwok
Venue: Communications of the ACM (1988)

A new contour generating serial algorithm is faster and more efficient than conventional contour tracing and parallel algorithms
Two fast implementations of the &ldquo;minimal standard&rdquo; random number generator
Authors: David F. Carta
Venue: Communications of the ACM (1990)

Although superficially time-consuming, on 32-bit computers the minimal standard random number generator can be implemented with surprising economy.
A uniform approach toward handling atomic and structured information in the nested relational database model
Authors: Marc Gyssens, Dirk van Gucht
Venue: Journal of the ACM (JACM) (1989)

The algebras and query languages for nested relations defined thus far do not allow us to &ldquo;flatten&rdquo; a relation scheme by disregarding the internal representation of data. In real life, however, the degree in which the structure of certain information, such as addresses, phone numbers, etc., is taken into account depends on the particular application and may even vary in time. Therefore, an algebra is proposed that does allow us to simplify relations by disregarding the internal structure of a certain class of information. This algebra is based on a careful manipulation of attribute names. Furthermore, the key operator in this algebra, called &ldquo;copying,&rdquo; allows us to deal with various other common queries in a very uniform manner, provided these queries are interpreted as operations on classes of semantically equivalent relations rather than individual relations. Finally, it is shown that the proposed algebra is complete in the sense of Bancilhon and Paredaens.
Structured analysis and object oriented analysis
Authors: Dennis de Champeaux, Larry Constantine, Ivar Jacobson, Stephen Mellor, Paul Ward, Edward Yourdon
Venue: Proceedings of the European conference on object-oriented programming on Object-oriented programming systems, languages, and applications (1990)

The object-oriented paradigm still faces an open challenge: Delivering huge software systems routinely and cost effectively. To quote Ed Yourdon: &ldquo;A system composed of 100,000 lines of C++ is not be sneezed at, but we don't have that much trouble developing 100,000 lines of COBOL today. The real test of OOP will come when systems of 1 to 10 million lines of code are developed.&rdquo; Although the object-oriented community has an opening flirtation with exploratory programming and rapid prototyping by exploiting reuse via inheritance, there is for now, in my opinion, no hope that huge systems can be developed without giving due attention to what a target system is supposed to do. Which should produce an (electronic) (graphical) (Pseudo-formal) document, the requirements, that a customer can initially sign off. We believe as well that for huge systems a programming language independent design activity, that bridges the requirements and the actual programming effort, is mandatory. It goes without saying that we do not suggest that these activities constitute a waterfall sequence. Consequently, the object-oriented community needs to address the question whether well established analysis techniques, like Structured Analysis, Jackson's JSD, etc. can be reused for object-oriented system development or whether a dedicated object-oriented analysis (and design) method is called for. The panel members have been asked to consider the following of question: What is the relationship between Structured Analysis (SA) and Object Oriented Analysis (OOA)? More specifically: Can SA be used effectively to produce the requirements for a system that will be designed and implemented in an OO fashion? If not, is it possible to adjust SA, what needs to be added? If SA cannot be used at all, what is the key obstacle? In case SA and OOA have different applicability ranges, how do we circumscribe &mdash; positively and negatively - these ranges? Any overlap? We appreciate that the organizing committee of this conference has selected this crucial topic.
Computing in permutation and matrix groups III: Sylow subgroups
Authors: Gregory Butler, John Cannon
Venue: Journal of Symbolic Computation (1989)

The ability of construct the Sylow subgroups of a large finite permutation or matrix group is fundamentalto a number of important algorithms for analyzing the abstract structure of such a group. In this paper we describe a backtrack algorithm which constructs a Sylow subgroup by successive cyclic extensions, starting with a cyclic subgroup of p-power order. The algorithm is capable of finding Sylow p-subgroups of order up to p^1^0, for small primes p, in permutation groups having a degree of several hundred.
Programming with explicit metaclasses in Smalltalk-80
Authors: J.-P. Briot, P. Cointe
Venue: ACM SIGPLAN Notices (1989)

This paper discusses the introduction of explicit metaclasses &aacute; la ObjVlisp into the Smalltalk-80 language. The rigidity of Smalltalk metaclass architecture motivated this work. We decided to implement the ObjVlisp model into the standard Smalltalk-80 system. The resulting combination defines the Classtalk platform. This platform provides a full-size environment to experiment with class-oriented programming by combining implicit metaclasses &aacute; la Smalltalk and explicit metaclasses &aacute; la ObjVlisp. Obviously, these experiments are not limited to the Smalltalk world and will be useful to understand and practice the metaclass concept advocated by modern object-oriented languages such as ObjVlisp and CLOS.
Semantic analysis during exploratory learning
Authors: Andrew Howes, Stephen J. Payne
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: Empowering people (1990)

This paper addresses the problem of how a novice computer user, engaged in exploratory learning, accounts for the behaviour of the device. Exploratory learning is the norm for many users who encounter computers in the work place. Exploratory learners must acquire methods from a suboptimal stream of task directed behaviour and its observable effects. A candidate model of analysis, EXPL [9] is taken as the baseline for the development of a new model, called Explor, which employs semantic knowledge of the lexical items used in the interface to relate user actions to system responses. The strengths and weaknesses of Explor are illustrated and discussed.
Benchmark calculations with an unstructured grid flow solver on a SIMD computer
Authors: J. S. Clary, G. A. Howell, Jr. S. L. Karman
Venue: Proceedings of the 1989 ACM/IEEE conference on Supercomputing (1989)

An unstructured grid flow solver was implemented on a massively parallel computer, and benchmark computations were performed. The solver was a two-dimensional computational fluid dynamics (CFD) code that performs first-order, steady-state solutions of the Euler equations. The parallel computer employed was the Connection Machine made by Thinking Machines, Corp. The CFD code was programmed in *Lisp, the accuracy of the code was verified, and numerous optimizations were implemented. Several benchmark runs were then made to assess and understand the impact of the code modifications and to obtain meaningful performance comparisons with other advanced computers.
Higher-order modules and the phase distinction
Authors: Robert Harper, John C. Mitchell, Eugenio Moggi
Venue: Proceedings of the 17th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

In earlier work, we used a typed function calculus, XML, with dependent types to analyze several aspects of the Standard ML type system. In this paper, we introduce a refinement of XML with a clear compile-time/run-time phase distinction, and a direct compile-time type checking algorithm. The calculus uses a finer separation of types into universes than XML and enforces the phase distinction using a nonstandard equational theory for module and signature expressions. While unusual from a type-theoretic point of view, the nonstandard equational theory arises naturally from the well-known Grothendieck construction on an indexed category.
Perturbation analysis of Horner's method for nice cases
Authors: C. B. Dunham
Venue: ACM SIGNUM Newsletter (1989)

Under favourable conditions, evaluation of polynomials by Homer's rule has an error not exceeding a few units in the last place.It has been observed that for moderate sized x and coefficients decreasing rapidly in magnitude that floating point evaluation of polynomials by Homer's method gives results accurate to around one or two units in the last place. A hand calculated example together with an informal justification is given by Fike (1968, pp. 52--53). In this note the observation is justified by a Wilkinson-type backward error analysis. It would be helpful for the reader to be familiar with the approach of Wilkinson (1963, Chap. 1), in which fl (expr) denotes the effect of evaluation of expression expr in floating point.We will assume that floating point is done using guard digits (Johnston, 1982, p. 11: Sterbenz, 1974) in which case we have by analysis similar to those of Wilkinson (1963, Chap. 1).
Computer aids for vision and employment (CAVE)
Authors: Douglas Griffith, Hodge Doss, David Winfree
Venue: ACM SIGCHI Bulletin (1988)

The percentage of blind and visually impaired (VI) adults of working age who are gainfully employed is approximately 33%. The confluence of two factors, the changing nature of the world of work and developments in microcomputer technology, offer the potential of greatly reducing the magnitude of this problem. In the information age a strong majority of jobs can be classified as information processing jobs. Given suitable adaptations, the blind and VI can perform such jobs using microcomputers.
Bidding Against Competitors
Authors: Chung-Kuo Chang
Venue: IEEE Transactions on Software Engineering (1990)

Consideration is given to a system of n competitors, where if a competitor selects its bids equally likely from a given set of bid values, its probability of winning is guaranteed to be 1/n, regardless of the bid values selected by other competitors in the system. A discussion is presented of several variations of this basic scheme, namely, bidding with unequal weights, bidding with more than one winner, and bidding with an unknown number of competitors. Two economical, but approximate, bidding schemes are discussed. In the first scheme, the competitors select their bids from a set with a constant size, and in the second, each competitor selects only one bid even though the total number of competitors is not known a priori. It is shown how to use these bidding schemes to construct solutions to several problems in distributed systems, including the mutual exclusion problem and the dining philosophers problem.
Design and Analysis of Arbitration Protocols
Authors: Fayez El-Guibaly
Venue: IEEE Transactions on Computers (1989)

Arbitration protocols are needed to prevent conflicts when several processors share a common resource. Five arbitration protocols, commonly used in digital systems, are modeled and their hardware implementations are discussed. The effect of the chosen protocol on the performance of the system, access time (delay before the bus is available) and data throughput (channel utilization efficiency) for each processor, can be studied using the models for these protocols. Four of the protocols considered are identified as being suitable for multiprocessor systems. It is shown that the rotating-priority protocol gives the best system performance. The fifth protocol, the unequal-priority protocol, is shown to offer the worst performance. This is because the protocol was originally intended for single-processor systems. Hardware schemes for the other four protocols are proposed. The schemes are decentralized and require a smaller number of communication lines between the processors. Live insertion and removal of processors from the system is possible since bus-status information is available to all processors at all times.
Multi-level shared caching techniques for scalability in VMP-M/C
Authors: D. R. Cheriton, H. A. Goosen, P. D. Boyle
Venue: ACM SIGARCH Computer Architecture News (1989)

The problem of building a scalable shared memory multiprocessor can be reduced to that of building a scalable memory hierarchy, assuming interprocessor communication is handled by the memory system. In this paper, we describe the VMP-MC design, a distributed parallel multi-computer based on the VMP multiprocessor design, that is intended to provide a set of building blocks for configuring machines from one to several thousand processors. VMP-MC uses a memory hierarchy based on shared caches, ranging from on-chip caches to board-level caches connected by busses to, at the bottom, a high-speed fiber optic ring. In addition to describing the building block components of this architecture, we identify the key performance issues associated with the design and provide performance evaluation of these issues using trace-drive simulation and measurements from the VMP. This work was sponsored in part by the Defense Advanced Research Projects Agency under Contract N00014-88-K-0619.
Integrating IBIS simulations and systems planning models through multiple model communications
Authors: M. G. Ketcham, R. Rajagopalan
Venue: Proceedings of the 21st conference on Winter simulation (1989)

This paper describes a multiple-process, multiple-windowed environment that allows users to interact with several models concurrently, including IBIS simulations. One goal in designing this environment is the transparent integration of simulation with other types of models, such as mathematical models for production planning. Its capabilities include interactive development of experiment specifications, automatic reconfiguration of simulations based on changing system specifications, and concurrent execution of simulations and production scheduling models to provide a detailed analysis of system capacities. Concurrent execution is controlled through techniques for multiple model communication.
Cache performance of the integer SPEC benchmarks on a RISC
Authors: Dionisios N. Pnevmatikatos, Mark D. Hill
Venue: ACM SIGARCH Computer Architecture News (1990)

SPEC is a new set of benchmark programs designed to measure a computer system's performance. The performance measured by benchmarks is strongly affected by the existence and configuration of cache memory. In this paper we evaluate the cache miss ratio of the Integer SPEC benchmarks. We show that the cache miss ratio depends strongly on the program, and that large caches are not completely exercised by these benchmarks.
Algorithm 679: A set of level 3 basic linear algebra subprograms: model implementation and test programs
Authors: J. J. Dongarra, Jermey Du Cruz, Sven Hammerling, I. S. Duff
Venue: ACM Transactions on Mathematical Software (TOMS) (1990)

This paper describes a model implementation and test software for the Level 2 Basic Linear Algebra Subprograms (Level 2 BLAS). Level 2 BLAS are targeted at matrix-vector operations with the aim of providing more efficient but portable, implementations of algorithms on high-performance computers. The model implementation provides a portable set of FORTRAN 77 Level 2 BLAS for machines where specialized implementations do not exists or are not required. The test software aims to verify that specialized implementations meet the specification of Level 2 BLAS that implementations are correctly installed
The relationships between online help systems and print documentation: an empirical investigation
Authors: A. Embad
Venue: Proceedings of the 7th annual international conference on Systems documentation (1989)

Issues addressing the time needed to learn a software system and the effectiveness of the communication between the end-user and a software system have been receiving attention over the past decade [e.g., Emdad, 1988, Pepper, 1981, Way, 1982]. This paper reports on an empirical investigation on the instructional effectiveness of the printed software documentation versus the online help facilities of a software system.
An array-theoretic look beyond APL2 and Nial
Authors: Trenchard More,  Jr.
Venue: ACM SIGAPL APL Quote Quad (1990)

The extended abstract below outlines the main points of a more complete paper in preparation. The purpose of the paper is to trace seven lines of development that have carried array theory from some of its original questions through a succession of intermediate answers to current suggestions for a more coherent theory. The paper explains the algebraic motivations for the theory and how and why the treatment of empty arrays in the Nested Interactive Array Language, Nial, differ from that in APL2. The paper introduces modular indexing, indexing from the end of an axis with negative indices, arrays viewed as tori, arithmetical and Boolean operations on non-numbers and nontruth values, and a purely structural operation underlying reshaping.