ppxscal/embedding_network huggingface dataset:
Groupwork close up: a comparison of the group design process with and without a simple group editor
Authors: Judith S. Olson, Gary M. Olson, Marianne Storrøsten, Mark Carter
Venue: ACM Transactions on Information Systems (TOIS) (1993)

A simple collaborative tool, a shared text editor called ShrEdit, changed the way groups of designers performed their work, and changed it for the better. First, the designs produced by the 19 groups of three designers were of higher quality than those of the 19 groups who worked with conventional whiteboard, paper and pencil. The groups with the new tool reported liking their work process a little less, probably because they had to adapt their work style to a new tool. We expected, from the brainstorming literature and recent work on Group Support Systems, that the reason the designs were of better quality was that the supported groups generated more ideas. To our surprise, the groups working with ShrEdit generated fewer design ideas, but apparently better ones. It appears that the tool helped the supported groups keep more focused on the core issued in the emerging design, to waste less time on less important topics, and to capture what was said as they went. This suggests that small workgroups can capitalize on the free access they have to a shared workspace, without requiring a facilitator or a work process embedded in the software.
Synchronous relaxation for parallel simulations with applications to circuit-switched networks
Authors: Stephen G. Eick, Albert G. Greenberg, Boris D. Lubachevsky, Alan Weiss
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (1993)

Synchronous relaxation, a new, general-purpose, efficient method for parallel simulation, is proposed. The method is applied to obtain a new parallel algorithm for simulating large circuit-switched communication networks. To show that synchronous-relaxation method is efficient, we present the results of circuit-switched network simulation experiments, and analytic approximations derived from a mathematical model of the simulation method.
Precise instruction scheduling without a precise machine model
Authors: Henry G. Baker
Venue: ACM SIGARCH Computer Architecture News (1991)

A simple technique is presented which allows an optimizing compiler to more precisely compare the performance of alternative instruction sequences on a complex RISC architecture so that the better sequence can be chosen. This technique may be faster than current techniques, and has the advantage that minor modifications to the hardware do not require any changes to the compiler (not even recompilation), and yet have an immediate effect on instruction scheduling decisions.
Constraint-based languages and systems (abstract)
Authors: Bjorn Freeman-Benson, Alan Borning
Venue: ACM SIGPLAN OOPS Messenger (1993)

Constraint-Based Languages and Systems Bjom Freeman-Benson , University of Victoria, Canada Alan Boming, University of Washington A constraint is a relation that should be satisfied, for example, that a line remain horizontal, that a resistor in an electrical circuit simulation obey Ohms Law, or that the height of a bar in a bar chart be proportional to some number in an application program. Constraints have been used in a variety of languages and systems, particularly in user interface tool kits, in planning and scheduling, and in simulation. They provide an intuitive declarative style of programming that integrates well with object-oriented systems. This tutorial teaches what constraints are, how to use them in applications such as user interfaces, how to implement them (including how to implement constraint hierarchies), and how to embed them in object-oriented and logic programming languages. You dont have to know anything about constraints, but it would be helpful to have a strong background in programming languages.
On computing condition numbers for the nonsymmetric eigenproblem
Authors: Z. Bai, James Demmel, A. McKenney
Venue: ACM Transactions on Mathematical Software (TOMS) (1993)

We review the theory of condition numbers for the nonsymmetric eigenproblem and give a tabular summary of bounds for eigenvalues, means of clusters of eigenvalues, eigenvectors, invariant subspaces, and related quantities. We describe the design of new algorithms for estimating these condition numbers. Fortran subroutines implementing these algorithms are in the LAPACK library [1].
Developing efficient relationships with I/S vendors: a contingency framework
Authors: Robert Klepper
Venue: Proceedings of the 1993 conference on Computer personnel research (1993)

This paper proposes a contingency framework for answering the questions: What is the range of options available in outsourcing relationships? And, how can the best, most appropriate relationship be identified? Answers to these questions are important because of the considerable resources that will be devoted to outsourcing in the future. A case study analysis is proposed for a test of the framework.
MURAX: a robust linguistic approach for question answering using an on-line encyclopedia
Authors: Julian Kupiec
Venue: Proceedings of the 16th annual international ACM SIGIR conference on Research and development in information retrieval (1993)

Robust linguistic methods are applied to the task of answering closed-class questions using a corpus of natural language. The methods are illustrated in a broad domain: answering general-knowledge questions using an on-line encyclopedia. A closed-class question is a question stated in natural language, which assumes some definite answer typified by a noun phrase rather than a procedural answer. The methods hypothesize noun phrases that are likely to be the answer, and present the user with relevant text in which they are marked, focussing the user's attention appropriately. Furthermore, the sentences of matching text that are shown to the user are selected to confirm phrase relations implied by the question, rather than being selected solely on the basis of word frequency. The corpus is accessed via an information retrieval (IR) system that supports boolean search with proximity constraints. Queries are automatically constructed from the phrasal content of the question, and passed to the IR system to find relevant text. Then the relevant text is itself analyzed; noun phrase hypotheses are extracted and new queries are independently made to confirm phrase relations for the various hypotheses. The methods are currently being implemented in a system called MURAX and although this process is not complete, it is sufficiently advanced for an interim evaluation to be presented.
A family of genetic algorithm packages on a workstation for solving combinatorial optimization problems
Authors: Roger L. Wainwright
Venue: ACM SIGICE Bulletin (1994)

LibGA, HYPERGEN and GATutor represent a trio of in-house developed genetic algorithm software packages for conducting research in combinatorial optimization problems. For a variety of reasons, these packages were developed using the C programming language on a Unix platform, specifically a Sun workstation. We used these packages successfully in developing sequential and parallel genetic algorithms for solving numerous combinatorial optimization problems. Several of these combinatorial optimization research projects and their results are described.
The self-similarity and computer programs
Authors: Peter Kokol
Venue: ACM SIGPLAN Notices (1994)

The concept of fractals and their underlaying feature of self- similarity is now used in many scientific areas like philosophy, medicine, engineering etc, In the present paper I would like to present two examples in which the concept of self similarity is concerned with the characteristics of computer programs, namely structure of variables and the frequency of reserved words and operators (Zipf's Low).It is always better to say right out what you think without trying to prove anything much: for all our proofs are only variations of our opinions, and the contrary-minded listen neither to one nor other.
Intermediate Smalltalk (abstract): practical design and implementation
Authors: Trygve Reenskaug
Venue: Addendum to the proceedings on Object-oriented programming systems, languages, and applications (Addendum) (1992)

Intermediate Smalltalk: Practical Design and Implementation Trygve Reenskaug, TASKON , Norway Careful design before programming is as important in Smalltalk as in other languages. This tutorial describes techniques that have proven useful in commercial development of large Smalltalk systems. The tutorial shows how to develop a language independent design and then go to detailed programming and testing. The examples will be based on Smalltalk-80 and use the release 4.1 graphical user interface framework.
Compatible tetrahedralizations
Authors: Marshall Bern
Venue: Proceedings of the ninth annual symposium on Computational geometry (1993)

We give some special-case tetrahedralization algorithms. We first consider the problem of finding a tetrahedralization compatible with a fixed triangulation of the boundary of a polyhedron. We then adapt our solution to the related problem of compatibly tetrahedralizing the interior and exterior of a polyhedron. We also show how to tetrahedralize the region between nested convex polyhedra with O(n log n) tetrahedra and no Steiner points.
A Decomposition of the Descent Algebra of a Finite Coxeter Group
Authors: F. Bergeron, N. Bergeron, R. B. Howlett, D. E. Taylor
Venue: Journal of Algebraic Combinatorics: An International Journal (1992)

The purpose of this paper is twofold. First we aim to unify previous work by the first two authors, A. Garsia, and C. Reutenauer (see &lsqb;2&rsqb;, &lsqb;3&rsqb;, &lsqb;4&rsqb;, &lsqb;5&rsqb; and &lsqb;10&rsqb;) on the structure of the descent algebras of the Coxeter groups of type An and Bn. But we shall also extend these results to the descent algebra of an arbitrary finite Coxeter group W. The descent algebra, introduced by Solomon in &lsqb;14&rsqb;, is a subalgebra of the group algebra of W. It is closely related to the subring of the Burnside ring B(W) spanned by the permutation representations W/WJ, where the WJ are the parabolic subgroups of W. Specifically, our purpose is to lift a basis of primitive idempotents of the parabolic Burnside algebra to a basis of idempotents of the descent algebra.
Object oriented relational database with SQL interface
Authors: Behrooz Seyed-Abbassi
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

An object oriented relational database management system to support heterogeneous object classes of statistical (numeric and text), image, text and sound information is considered. By employing a user friendly interface and Structured Query Language (SQL) capability at the user level, this database with a three level architecture utilizes an extended SQL to operate on complex objects and to support database processing functions such as retrieve, join and overlay. These operations also support the conversion of statistical data into two or three dimensional images to assist in the decision making process. The C++ programming language is being utilized for implementation. By supporting heterogeneous object classes (files), this object oriented relational database design and implementation improves capabilities for multipurpose database systems to facilitate financial, medical and mathematical needs for diagnosis and comparative analysis by integrating and unifying information into one database system.
Extracting polyvariant binding time analysis from polyvariant specializer
Authors: Mikhail A. Bulyonkov
Venue: Proceedings of the 1993 ACM SIGPLAN symposium on Partial evaluation and semantics-based program manipulation (1993)

Polyvariant binding time analysis allows a program to be transformed for improving propagation and usage of static information. It could be a useful instrument for better specializability. We show that the process of such a transformation is of the same nature as the whole specialization process. Moreover, we present a practical method for realizing polyvariant binding time analysis based on the double application of a polyvariant specializer. The proposed technique is restricted to first order programs with strict semantics. &mdash;Author's Abstract
Celebrating a decade of joyful innovation: HCIL's 10th annual symposium and open house
Authors: Sylvia B. Sheppard, Elizabeth D. Murphy
Venue: ACM SIGCHI Bulletin (1993)

With abundant joy and hospitality, the University of Maryland's Human-Computer Interaction Laboratory (HCIL) marked its 10-year anniversary on June 10, 1993. Ben Shneiderman, Head of the HCIL, welcomed over 200 attendees to the symposium and open house. Azriel Rosenfeld, Director of the University's Center for Automation Research, greeted the audience. The Center includes the HCIL, which spans the departments of Computer Science and Psychology and the College of Library and Information Services.
A Graham-Sloane Type Construction for s-Surjective Matrices
Authors: Iiro Honkala
Venue: Journal of Algebraic Combinatorics: An International Journal (1992)

We give a construction of (n&minus;s)-surjective matrices with n columns over \Bbb {Z}_q using Abelian groups and additive s-bases. In particular we show that the minimum number of rows msq(n,n&minus;s) in such a matrix is at most ssqn&minus;s for all q, n and s.
Differential cryptanalysis of hash functions based on block ciphers
Authors: Bart Preneel, Rene Govaerts, Joos Vandewalle
Venue: Proceedings of the 1st ACM conference on Computer and communications security (1993)

This paper describes a differential attack on several hash functions based on a block cipher. The emphasis will be on the results for cases where DES [8] is the underlying block cipher. It will briefly discuss the case of FEAL-N [19, 21].
Lazy caching
Authors: Yehuda Afek, Geoffrey Brown, Michael Merritt
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1993)

This paper examines cache consistency conditions for multiprocessor shared memory systems. It states and motivates a weaker condition than is normally implemented. An algorithm is presented that exploits the weaker condition to achieve greater concurrency. The algorithm is shown to satisfy the weak consistency condition. Other properties of the algorithm and possible extensions are discussed.
An incremental algorithm for building temporal quadtrees
Authors: George F. Frazier
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

Research involving applications such as geographic information systems, digital cartography, machine-drawing understanding systems, and medical imaging systems has recently focused considerable attention on spatial databases that support temporal reasoning. To develop such applications, several spatiotemporal data models have been proposed. In this work, an incremental algorithm is presented for building temporal quadtrees from a sequence of time-stamped grids. The temporal quadtree data model is particularly well-suited for applications involving highly homogeneous spatiotemporal data. Analysis of the algorithm reveals that an upper bound on its execution time is proportional to the product of the number of time-stamped grids involved and the number of cells in each grid.
Visibility representations of planar graphs (abstract)
Authors: Ioannis G. Tollis
Venue: ACM SIGACT News (1993)

Interesting representations of graphs results from mapping vertices into horizontal segments and edges into vertical segments drawn between visible vertex-segments. (Two parallel segments of a given set are visible if they can be joined by a segment orthogonal to them, which does not intersect any other segment.) Such representations are called visibility representations. These representations find applications in VLSI layout, algorithm animation, visual languages and CASE tools. We consider three types of visibility representations: (i) Weakvisibility representation, if two vertices are adjacent then their corresponding segments must be visible. (ii) #949;-visibility representation, where vertices can be represented by open, closed, or semiclosed horizontal segments in the plane such that two vertices are adjacent if and only if their associated segments are visible. (iii) Strong-visibility representation, where vertices are represented by closed horizontal segments such that two vertices are adjacent if and only if their corresponding segments are visible. We discuss various types of visibility representations of planar graphs on the plane, cylinder, and sphere.
HCI '93: people and computers VIII: conference report, September 7&ndash;10, Loughborough, UK
Authors: Donald Day
Venue: ACM SIGCHI Bulletin (1994)

Three days of persistent rain and wind did not deter more than 160 industry and academic HCI specialists from attending HCI '93 at Loughborough University of Technology. Nearly one-third of registrants were from industry, two-thirds from academia. One-fifth were from abroad.
LogP: towards a realistic model of parallel computation
Authors: David Culler, Richard Karp, David Patterson, Abhijit Sahay, Klaus Erik Schauser, Eunice Santos, Ramesh Subramonian, Thorsten von Eicken
Venue: ACM SIGPLAN Notices (1993)

A vast body of theoretical research has focused either on overly simplistic models of parallel computation, notably the PRAM, or overly specific models that have few representatives in the real world. Both kinds of models encourage exploitation of formal loopholes, rather than rewarding development of techniques that yield performance across a range of current and future parallel machines. This paper offers a new parallel machine model, called LogP, that reflects the critical technology trends underlying parallel computers. it is intended to serve as a basis for developing fast, portable parallel algorithms and to offer guidelines to machine designers. Such a model must strike a balance between detail and simplicity in order to reveal important bottlenecks without making analysis of interesting problems intractable. The model is based on four parameters that specify abstractly the computing bandwidth, the communication bandwidth, the communication delay, and the efficiency of coupling communication and computation. Portable parallel algorithms typically adapt to the machine configuration, in terms of these parameters. The utility of the model is demonstrated through examples that are implemented on the CM-5.
A multi-agent analogical representation for physical objects (abstract)
Authors: Luca Maria Gambardella, Marc Haex
Venue: ACM SIGOIS Bulletin (1992)

In a multi-agent world, several agents act simultaneously, competitively or cooperatively. In many situations, an intelligent autonomous agent must interact with the other agents or the physical environment in real time. Because it cannot predict all the events that will occur in the physical environment or result from other agents reasoning, it must notice and control its responses to unanticipated events. However, insuring execution of the best possible operation conflicts with meeting deadlines, especially as the event rate and the number of known operations increase. Rather than engineer agents to meet deadlines under particular parameter values, we aim to build autonomous agents that control their reasoning so as to guarantee real-time performance despite increases in parameter values. We propose a satisficing algorithm. To control response time, it triggers only a limited number of operations and interrupts triggering to execute the best one available whenever it triggers a "good enough" operation or a deadline occurs. To insure that it can execute high-priority operations when interrupts occur, it uses dynamic control plans to trigger operations roughly "best-first." In this paper, we describe the satisficing algorithm, informally analyse the behavior of an agent under this algorithm, and present experimental results.
Techniques to overlap computation and communication in irregular iterative applications
Authors: Antonio Lain, Prithviraj Banerjee
Venue: Proceedings of the 8th international conference on Supercomputing (1994)

There are many applications in CFD and structural analysis that can be more accurately modeled using unstructured grids. Parallelization of implicit methods for unstructured grids is a difficult and important problem. This paper deals with coloring techniques to overlap computation and communication during the solution of implicit methods on message passing distributed memory multicomputers. An evaluation of coloring techniques for partitioned unstructured grids is first presented. Results show the importance of using partitioning information during coloring. It is next shown that overlapping computation and communication can be formalized as a generalized coloring problem. Modified coloring algorithms are used for this purpose. The PARTI library has been extended to support non-blocking gather-scatter operations and used in conjunction with these algorithms. Practicality issues are evaluated with experimental results on an Intel Paragon multicomputer.
The user-centered iterative design of collaborative writing software
Authors: Ronald M. Baecker, Dimitrios Nastos, Ilona R. Posner, Kelly L. Mawby
Venue: Proceedings of the INTERACT '93 and CHI '93 conference on Human factors in computing systems (1993)

This paper presents the user-centred iterative design of software that supports collaborative writing. The design grew out of a study of how people write together that included a survey of writers and a laboratory study of writing teams linked by a variety of communications media. The resulting taxonomy of collaborative writing is summarized in the paper, followed by a list of design requirements for collaborative writing software suggested by the work. The paper describes two designs of the software. The first prototype supports synchronous writing and editing from workstations linked over local area and wide area networks. The second prototype also supports brainstorming, outlining, and document review, as well as asynchronous work. Lessons learned from the user testing and actual usage of the two systems are also presented.
Multiple join size estimation by virtual domains (extended abstract)
Authors: Allen Van Gelder
Venue: Proceedings of the twelfth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1993)

A model is described to estimate the size of intermediate relations produced by large relational algebra expressions, in particular, those containing several equi-joins. The intended application is within query optimization searches, where fast estimates are needed as many alternative plans are examined. It is shown that previous methods, which use an independence assumption when several attributes are joined, can lead to unrealistically low size estimates. This method attempts to overcome that problem by the introduction of &ldquo;virtual domains&rdquo;, which avoid the independence assumption. The method does not require extensive statistics about the database. After describing an &ldquo;exact&rdquo; version, an approximation that is simpler and faster is presented.
Equivalence, query-reachability and satisfiability in Datalog extensions
Authors: Alon Levy, Inderpal Singh Mumick, Yehoshua Sagiv, Oded Shmueli
Venue: Proceedings of the twelfth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1993)

We consider the problems of equivalence, satisfiability and query-reachability for datalog programs with negation and dense-order constraints. These problems are important for optimizing datalog programs. We show that both query-reachability and satisfiability are decidable for programs with stratified negation provided that negation is applied only to EDB predicates or that all EDB predicates are unary. In the latter case, we show that equivalence is also decidable. The algorithms we present are also used to push constraints from a given query to the EDB predicates. Finally, we show that satisfiability is undecidable for datalog programs with unary IDB predicates, stratified negation and the interpreted predicate &ne;