ppxscal/embedding_network huggingface dataset:
Powermice and user performance
Authors: Herbert D. Jellinek, Stuart K. Card
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: Empowering people (1990)

Claims of increased pointing speed by users and manufacturers of variable-gain mice (&ldquo;powermice&rdquo;) have become rife. Yet, there have been no demonstrations of this claim, and theoretical considerations suggest it may not even be true. In this paper, the claim is tested. A search of the design space of powermice failed to find a design point that improved performance compared to a standard mouse. No setting for the gain for a constant-gain mouse was found that improved performance. No threshold setting for a variable gain mouse was found that improved performance. In fact, even gain and threshold combinations favored by powermouse enthusiasts failed to improve performance. It is suggested that the real source of enthusiasm for powermice is that users are willing to accept reduced pointing speed in return for a smaller desk footprint.
Interpretation in a tool-fragment environment
Authors: S. J. Zeil, E. C. Epp
Venue: Proceedings of the 10th international conference on Software engineering (1988)

The philosophy of composition of new software tools from previously created tool fragments is a useful approach to facilitating the development of software systems. This paper examines the extension of this philosophy to the design of program interpreters, demonstrating how the separation of interpretation into a core algorithm, value kind definitions, and computation model allows the capture of conventional execution models, symbolic execution models, dynamic data flow tracking, and other useful forms of program interpretation. An interpretation system based upon this separation, called ARIES, is currently under development.
On the implementation of applicative languages on shared-memory, MIMD multiproce
Authors: Ching-Cheng Lee, Stephen Skedzielewski, John Feo
Venue: Proceedings of the ACM/SIGPLAN conference on Parallel programming: experience with applications, languages and systems (1988)

This paper presents the performance of a set of algorithms written in SISAL [MSA*85] and run on multiprocessor Sequent, DEC, and Cray computers. We describe our current runtime system and discuss its implementation on each machine. We indicate where our automatic approach to parallelization works well, as well as sources of inefficient behavior. Overall we find our systems encouraging for the first release of the native-code generating software. We suggest improvements to the compiler and runtime systems, many already developed but not yet implemented, to alleviate the inefficiencies.
Real-Number Codes for Fault-Tolerant Matrix Operations on Processor Arrays
Authors: V. S. S. Nair, Jacob A. Abraham
Venue: IEEE Transactions on Computers (1990)

A generalization of existing real numer codes is proposed. It is proven that linearity is a necessary and sufficient condition for codes used for fault-tolerant matrix operations such as matrix addition, multiplication, transposition, and LU decomposition. It is also proven that for every linear code defined over a finite field, there exists a corresponding linear real-number code with similar error detecting capabilities. Encoding schemes are given for some of the example codes which fall under the general set of real-number codes. With the help of experiments, a rule is derived for the selection of a particular code for a given application. The performance overhead of fault tolerance schemes using the generalized encoding schemes is shown to be very low, and this is substantiated through simulation experiments.
Xinu/WU: an improved PC-Xinu clone?
Authors: J. Hummel
Venue: ACM SIGCSE Bulletin (1989)

In teaching an undergraduate course in Operating Systems, it is instructive if the students have an actual operating system they can study and modify. Care should be taken, however, in selecting a system that the students can realistically be expected to understand. Xinu/WU retains the advantages of its parent PC-Xinu [Fossum 1987]; a small yet relatively complete operating system for the IBM PC, supplied with full source code and able to run within its development environment. Xinu/WU incorporates three particular enhancements: an improved implementation, integration into Borland International's Turbo C&trade; run-time environment, and more effective use of the windowing system. The conclusion is that Xinu/WU increases the possibility of using such a system in an undergraduate Operating Systems course. Two ways in which it can be utilized are presented.
Computers and society: an integrated course model
Authors: William J. Joel
Venue: ACM SIGCAS Computers and Society (1989)

Curriculum '78 recommends that a course examining the social effects of computer technology be included in an undergraduate computer science degree. There are essentially three ways of examining various segments of society: application model, society type model and major issue model. The integrated course model incorporates all three simpler models and creates a course that allows the student to easily move from personal experiences to global issues.
An APL approach to differential calculus yields a powerful tool
Authors: R. D. Neidinger
Venue: ACM SIGAPL APL Quote Quad (1989)

An APL workspace is developed for the purpose of calculating numerical values of derivatives. The heart of the method, called automatic differentiation, is manipulation of numerical vectors --- an APL way of thinking. The method is not symbolic manipulation as taught in calculus, nor is it approximation as taught in numerical analysis. Automatic differentiation is implemented as a workspace (called GRADIENT) of 14 simple, one-line, numerical vector functions that perform all of the formal differentiation rules. The ideas are introduced for simple first derivatives of single variable functions. We then show that the GRADIENT workspace enables the calculation of all first-order partial derivatives of any typical function in any number of variables. This workspace is used as a tool in the solution of systems of nonlinear equations by Newton's method. Finally, we discuss how APL concepts led to a new approach to higher-order derivatives. This approach enables the calculation of higher-order derivatives for problems that overwhelm commercial symbolic differentiation programs; moreover, the resulting accuracy cannot be obtained by numerical approximation techniques.
Computer graphics visualization for acoustic simulation
Authors: A. Stettner, D. P. Greenberg
Venue: Proceedings of the 16th annual conference on Computer graphics and interactive techniques (1989)

Computer simulations can be used to generate the spatial and temporal data describing the acoustical behavior of performance halls, but typically the analytical results are difficult to assimilate and compare. By using computer graphics to display the multi-dimensional data, substantially greater amounts of information than that conveyed by standard techniques can be communicated to the designer. This allows designs of different acoustical spaces to be tested, evaluated, and compared.An example comparing the acoustical behavior of three different concert halls demonstrates these techniques and allows for the simultaneous assimilation of much of the information necessary to evaluate the acoustical nature of a space. The use of three-dimensional images, color, animation and abstract representation allows for the comprehension of the complex results of a scientific simulation. Specifically, the simultaneous display of particular icons familiar to the discipline enabled the simultaneous presentation of up to twelve parameters.From a more general point of view, the procedures demonstrate how computer graphics can be utilized for the portrayal of multi-dimensional time dependent data. The visualization techniques are potentially useful for the display of three-dimensional vector fields in many scientific and design applications.
Interacting with an active, integrated environment
Authors: Thomas Rodden, Pete Sawyer, Ian Sommerville
Venue: ACM SIGPLAN Notices (1989)

Software engineering environments are intended to provide a cohesive and integrated set of tools to support the process of software engineering with much current research into environment design focussed on maximising the degree to which these tools can be integrated. This paper describes the architecture of a prototype environment which attempts to achieve a high degree of integration using techniques drawn from artificial intelligence, office automation and object-oriented programming. This environment is implemented as a federation of intelligent, co-operating agents which communicate, with each other and with users, by message passing. This paper is particularly concerned with user interface integration including the mechanisms employed to permit inter-agent and agent-user communications.
Configuring stand-alone smalltalk-80 applications
Authors: S. Sridhar
Venue: ACM SIGPLAN Notices (1988)

The Smalltalk-80&trade; programming environment, though powerful for prototyping applications, does not have any mechanisms for constructing a stand-alone version of an application. Traditionally, the application is bundled with an image including the entire development environment. Production applications frequently require that the only interface visible to the end user be that of the application. A common misperception among Smalltalk-80 application developers is that it is impossible to: develop and deliver applications containing proprietary algorithms, prevent inspection and modification of the application, separate the development environment from the delivered application, provide annotation of the application classes and methods without actually revealing the source code to the end user. In this paper, we introduce various techniques and mechanisms for meeting these requirements.
Louis Couffignal, 1902-1966: Informatics Pioneer in France?
Authors: G. Ramunni
Venue: IEEE Annals of the History of Computing (1989)

The author examines the project of Louis Couffignal concerning an electronic calculating machine. This project was supported by the Centre National de la Recherche Scientifique. Couffignal was aware of the American and British projects concerning computers but he wanted to profoundly differentiate his project from them. He rejected the place of the memory in the new machines. Couffignal's machine was never finished and this failure caused a delay in computing science in France.
Evaluation of memory system for integrated Prolog processor IPP
Authors: M. Morioka, S. Yamaguchi, T. Bandoh
Venue: ACM SIGARCH Computer Architecture News (1989)

This paper discusses an optimal memory system to realize a high performance integrated Prolog processor, the IPP. First, the memory access characteristics of Prolog are analyzed by a simulator, which simulates the execution of a Prolog program at a micro instruction level. The main findings from this analysis are that: the write access ratio of Prolog is larger than that of procedural languages; and performance improvement requires the memory system to process concentrated, large write accesses effectively. Then the Prolog acceleration strategies for conventional cache memories are discussed. Comparison is made of cache memories (store-swap, store-through) and a stack buffer, regarding not only performance but also reliability, complexity and effects on procedural languages. The advanced store-through cache with a multi-stage write buffer and an interleaved main memory are seen to have the same performance level as the store-swap cache. When considering data reliability, the advanced store-through cache is judged more suitable for the IPP than the store-swap cache. In a comparison between stack buffer and advanced store-through cache, the stack buffer is found to achieve higher peak performance, but this is affected by the program features. On the other hand, the advanced store-through cache constantly gets high performance for Prolog and procedural languages. As a result, it is concluded that the advanced store-through cache is best suited to the IPP.
Multiparty protocols and logspace-hard pseudorandom sequences
Authors: L. Babai, N. Nisan
Venue: Proceedings of the twenty-first annual ACM symposium on Theory of computing (1989)

Let &fnof;(x1, &middot;&middot;&middot;&middot; xk) be a Boolean function that k parties wish to collaboratively evaluate. The i'th party knows each input argument except xi; and each party has unlimited computational power. They share a blackboard, viewed by all parties, where they can exchange messages. The objective is to minimize the number of bits written on the board. We prove lower bounds of the form &OHgr;(n&middot;c-k), for the number of bits that need to be exchanged in order to compute some (explicitly given) functions in P. Our bounds hold even if the parties only wish to have a 1% advantage at guessing the value of &fnof; on random inputs. We then give several applications of our lower bounds. Our first application is a pseudorandom generator for Logspace. We explicitly construct (in polynomial time) pseudorandom sequences of length n from a random seed of length exp(c&radic;logn) that no Logspace Turing machine will be able to distinguish from truly random sequences. As a corollary we give an explicit construction of universal traversal sequence of length exp(exp(c&radic;logn)) for arbitrary undirected graphs on n vertices. We then apply the multiparty protocol lower bounds to derive several new time-space tradeoffs. We give a tight time-space tradeoff of the form TS=&THgr;(n2), for general, k-head Turing-Machines; the bounds hold for a function that can be computed in linear time and constant space by a k+1-head Turing Machine. We also give a new length-width tradeoff for oblivious branching programs; in particular our bound implies new lower bounds on the size of arbitrary branching programs, or on the size of Boolean formulas (over an arbitrary finite base).
Circuit switching in multi-hop lightwave networks
Authors: I. Chlamtac, A. Ganz, G. Karmi
Venue: Symposium proceedings on Communications architectures and protocols (1988)

Emerging high speed networks are using optical fibers employing time division synchronous communication. In these systems the use of optical switching is strongly advocated due to the bottleneck created by store and forward in electronic components. Switching solutions geared toward optical systems have been proposed so far only for packet switching networks. This paper introduces a new circuit switching approach for the emerging time division controlled fiber optic networks based on the requirement to avoid store and forward at intermediate nodes. The approach, termed Fast Circuit Switching (FCS), is unique in several operational and performance aspects. In terms of the way time slots within each cycle are allocated, a circuit is guaranteed a transmission slot immediately upon arrival at every intermediate node. As a result, the proposed Fast Circuit Switching (FCS) can be implemented by pure optical switches. In terms of performance, FCS guarantees minimum data transmission delays, consisting only of the end to end propagation delay in the network. Lastly due to being based on fixed time allocation at intermediate nodes, the FCS controlled system is purely end to end controlled. These properties make FCS inherently suitable for efficiently implementing circuit switching in wide area fiber optic networks, particularly, for supporting real time communications. The realization of slot assignments, which support the FCS solution, entails a novel graph oriented algorithmic approach. Several new algorithms for allocating circuits according to FCS are presented, dealing with fixed, as well as dynamic, circuit management. It is shown that, while providing unique operational and performance advantages as discussed above, the FCS is also bandwidth efficient, requiring only system bandwidth similar to conventional circuit switching methodologies.
Subdivisions of n-dimensional spaces and n-dimensional generalized maps
Authors: P. Lienhardt
Venue: Proceedings of the fifth annual symposium on Computational geometry (1989)

This paper deals with the modeling of n-dimensional objects, more precisely with the modeling of subdivisions of n-dimensional topological spaces. We here study the notions of: n-dimensional generalized map (or n-G-map), for the modeling of the topology of any subdivision of any n-dimensional topological space (orientable or not orientable, with or without boundaries); n-dimensional map (or n-map), for the modeling of the topology of any subdivision of any orientable n-dimensional topological space, without boundaries. These two notions extend the notion of topological map, which has been used for the modeling of the topology of any subdivision of any surface. We study in this paper some properties of the n-G-maps and the n-maps (orientability, duality, relationships between n-G-maps and n-maps &hellip;), and we define also operations for constructing any n-G-map.
The software engineering process: definition and scope
Authors: W. S. Humphrey
Venue: ACM SIGSOFT Software Engineering Notes (1989)

With the growing interest in the software engineering process, it is increasingly important to define what we mean by these words. This, however, also requires definitions for software and software engineering as well as some agreement on the scope and boundaries of these activities.
The matters that really matter for hypertext usability
Authors: J. Nielsen
Venue: Proceedings of the second annual ACM conference on Hypertext (1989)

We compare 92 benchmark measurements of various usability issues related to hypertext which have been published in the hypertext literature in order to find which ones have shown the largest effects.
The layout synthesizer: an automatic Netlist-to-Layout system
Authors: C. C. Chen, S.-L. Chow
Venue: Proceedings of the 26th ACM/IEEE Design Automation Conference (1989)

A system generating compacted physical layouts from MOS transistor netlists has been developed. It uses a novel graph-theoretical placement algorithm to simultaneously maximize diffusion sharing and minimize the wiring area. The algorithm is not limited to circuits that have equal numbers of NMOS and PMOS transistors. A special-purpose router using either one-layer or two-layer metal is described. Experimental results for area efficiency and run-time performance are very promising.
Adaptive routing in Burroughs network architecture
Authors: J. L. Rosenberg, S. A. Gruchevsky, D. M. Piscitello
Venue: Proceedings of the ACM workshop on Frontiers in computer communications technology (1987)

The routing function used for Burroughs Network Architecture (BNA) to determine the best routes for traffic through the network is known as the Burroughs Integrated Adaptive Routing System, or BIAS&trade;1 Based on the algorithm devised for the MERIT Computer Network [3], BIAS&trade; is a decentralized, deterministic system which adapts to changes in network topology automatically. The Current BIAS&trade; routing architecture incorporates improvements [1] in the original algorithm which significantly reduce the recovery time from failures of nodes or links and is virtually loop-free, even during recovery from those failures. BIAS&trade; automatically re-determines the best routes for traffic throughout the network in response to the following changes to the network topology: a node (an end system or intermediate system) is added to the network; a node is removed from the network; the cost of transiting a node is changed; a logical link (LAN, leased or switched circuit, X.25 virtual circuit) is added to the network; a link is removed from the network; and/or the cost of transiting a link is changed.
Helgon: extending the retrieval by reformulation paradigm
Authors: G. Fischer, H. Nieper-Lemke
Venue: ACM SIGCHI Bulletin (1989)

People who attempt to use a complex information store on a computer encounter a number of problems: They do not know what information exists or how to find information, they get no support in articulating a question, and they are unable to phrase their question in terms that the system understands. Helgon, an intelligent environment that supports limited cooperative problem solving, helps people deal with complex information stores. Helgon supports retrieval and editing by reformulation with multiple specification techniques, and it acquaints the user with the system model of the information store. Within the current Helgon system, a number of different information stores have been implemented. Empirical evaluations have shown that Helgon supports effective communication. In addition, the evaluations have shown interesting extensions for future work.
An Ada multitasking solution for the sieve of Eratosthenes
Authors: G. Anderson
Venue: ACM SIGAda Ada Letters (1988)

The Sieve of Eratosthenes, an algorithm for calculating prime numbers, has been used for years as a benchmark for evaluating the processing power of single CPUs. A recent modification to the sieve algorithm provides a concurrent solution method for calculating prime numbers. This paper describes an Ada program which uses a multitasking solution for the Sieve of Eratosthenes. The program illustrates the use of Ada tasking to obtain concurrency in the solution of compute-intensive numerical algorithms and may also serve as a benchmark program for evaluating multiple CPU systems.
Application frameworks: experience with MacApp
Authors: John R. Pugh, Cafee Leung
Venue: ACM SIGCSE Bulletin (1988)

It is an unfortunate truth that as personal computers have become easier to use they also have become more difficult to program. Students who want to write programs that look and feel like real Macintosh applications, for example, are constrained by the time available and the sheer complexity of the application development process. We have found that several object-oriented programming systems have succeeded in abstracting out the commonalties of graphical user interfaces and can allow students to construct interactive, graphical applications at a lower cost. In this paper we describe our experiences in the use of MacApp, an application framework for the Apple Macintosh. The design and implementation of Prof, a prototype visual programming system for both educators and students developed by a final year student in a thirteen week project course, is used to illustrate the discussion. We describe the advantages and disadvantages of the object-oriented application framework approach in the expectation that our experiences will be useful for other educators who may be contemplating following this path.
Clustering algorithms based on minimum and maximum spanning trees
Authors: T. Asano, B. Bhattacharya, M. Keil, F. Yao
Venue: Proceedings of the fourth annual symposium on Computational geometry (1988)

We consider clustering problems under two different optimization criteria. One is to minimize the maximum intracluster distance (diameter), and the other is to maximize the minimum intercluster distance. In particular, we present an algorithm which partitions a set S of n points in the plane into two subsets so that their larger diameter is minimized in time &Ogr;(n log n) and space &Ogr;(n). Another algorithm with the same bounds computes a k-partition of S for any k so that the minimum intercluster distance is maximized. In both instances it is first shown that an optimal parition is determined by either a maximum or minimum spanning tree of S.