ppxscal/embedding_network huggingface dataset:
Gardeners and gurus: patterns of cooperation among CAD users
Authors: Michelle Gantt, Bonnie A. Nardi
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

We studied CAD system users to find out how they use the sophisticated customization and extension facilities offered by many CAD products. We found that users of varying levels of expertise collaborate to customize their CAD environments and to create programmatic extensions to their applications. Within a group of users, there is at least one local expert who provides support for other users. We call this person a local developer. The local developer is a fellow domain expert, not a professional programmer, outside technical consultant or MIS staff member. We found that in some CAD environments the support role has been formalized so that local developers are given official recognition, and time and resources to pursue local developer activities. In general, this formalization of the local developer role appears successful. We discuss the implications of our findings for work practices and for software design.
Conceptual Modeling of Multimedia Documents
Authors: Carlo Meghini, Fausto Rabitti, Costantino Thanos
Venue: Computer (1991)

An approach to the document-retrieval problem that aims to increase the efficiency and effectiveness of document-retrieval systems by exploiting the semantic contents of the documents is presented. The document retrieval problem is delineated, and conceptual document modeling basics and requirements are discussed. An experimental system, the Multimedia Office Server (Multos), which implements some of the document-model concepts described, is presented.
The senior seminar in computer science
Authors: Richard J. Arras, Lewis Motter
Venue: ACM SIGCSE Bulletin (1990)

This paper considers the senior seminar course in computer science and discusses its place in preparing students for careers in computer science. It is the authors' contention that the senior seminar should attempt to prepare students for the practice of computer science in the work place. It considers the various aspects of the development and implementation of a significant user-oriented software project that serves as the cornerstone of such a course.
Beyond being there
Authors: Jim Hollan, Scott Stornetta
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

A belief in the efficacy of imitating face-to-face communication is an unquestioned presupposition of most current work on supporting communications in electronic media. In this paper we highlight problems with this presupposition and present an alternative proposal for grounding and motivating research and development that frames the issue in terms of needs, media, and mechanisms. To help elaborate the proposal we sketch a series of example projects and respond to potential criticisms.
LAPACK is now available
Authors: Jack Dongarra
Venue: ACM SIGNUM Newsletter (1992)

LAPACK is a transportable library of Fortran 77 subroutines for solving the most common problems in numerical linear algebra: systems of linear equations, linear least squares problems, eigenvalue problems, and singular value problems. It has been designed to be efficient on a wide range of modern high-performance computers.
A tree-trellis based fast search for finding the N Best sentence hypotheses in continuous speech recognition
Authors: Frank K. Soong, Eng-Fong Huang
Venue: Proceedings of the workshop on Speech and Natural Language (1990)

In this paper a new, tree-trellis based fast search for finding the <i>N</i> best sentence hypotheses in continuous speech recognition is proposed. The search consists of two parts: a forward, time-synchronous, trellis search and a backward, time asynchronous, tree search. In the first module the well known Viterbi algorithm is used for finding the best hypothesis and for preparing a map of all partial paths scores time synchronously. In the second module a tree search is used to grow partial paths backward and time asynchronously. Each partial path in the backward tree search is rank ordered in a stack by the corresponding full path score, which is computed by adding the partial path score with the best possible score of the remaining path obtained from the trellis path map. In each path growing cycle, the current best partial path, which is at the top of the stack, is extended by one arc (word). The new tree-trellis search is different from the traditional time synchronous Viterbi search in its ability for finding not just the best but the <i>N</i>-best paths of different word content. The new search is also different from the <i>A</i> algorithm, or the stack algorithm, in its capability for providing an exact, full path score estimate of any given partial (i.e., incomplete) path before its completion. When compared with the best candidate Viterbi search, the search complexities for finding the <i>N</i>-best strings are rather low, i.e., only a fraction more computation is needed.
How accurate should numerical routines be?
Authors: Charles B. Dunham
Venue: ACM SIGNUM Newsletter (1990)

J. H. Wilkinson, in justifying backward error analyses, advanced the proposition that a numerical routine could not be blamed if the computed answer was the exact answer to the problem with slightly perturbed input. Such a model was established by Wilkinson (1968) for the solution of linear equations, ns by (I) Gaussian elimination and (II) triangular decomposition using double precision accumulation of inner products. In the latter it is usual that inputs are perturbed only by a small multiple of a unit rounding error (see formula (175)).
On the complexity of some geometric problems in unbounded dimension
Authors: Nimrod Megiddo
Venue: Journal of Symbolic Computation (1990)

This paper examines the complexity of several geometric problems due to unbounded dimension. The problems considered are: (i) minimum cover of points by unit cubes, (ii) minimum cover of points by unit balls, and (iii) minimum number of lines to hit a set of balls. Each of these problems is proven not to have a polynomial approximation scheme unless P = NP. Specific lower bounds on the error ratios attainable in polynomial time are given, assuming P
Information Dissemination in Trees with Nonuniform Edge Transmission Times
Authors: Jae-moon Koh, Dong-wan Tcha
Venue: IEEE Transactions on Computers (1991)

The information dissemination process in a tree is considered. It is assumed that a vertex can either transmit or receive a message and an informed vertex can transmit it to only one of its neighbors at a time. For the case of uniform edge transmission times, P. Slater et al. (1981) showed that a simple ordering policy achieves the minimum broadcast time and presented an algorithm which determines a set of broadcast centers. It is shown that a simple ordering policy is still optimal for the case of nonuniform edge transmission times, and modifications of the algorithm that enables it to solve this general problem within O(N log N) time are suggested.
Scheduling parallel machines on-line
Authors: David B. Shmoys, Joel Wein, David P. Williamson
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

The authors study the problem of scheduling jobs on parallel machines when the existence of a job is not known until an unknown release date and the processing requirement of a job is not known until the job is processed to completion. They demonstrate two general algorithmic techniques for converting existing polynomial-time algorithms that require complete knowledge about the input data into algorithms that need less advance knowledge. They prove information-theoretic lower bounds on the lengths of online schedules for several basic parallel machine models and then show that the algorithms construct schedules with lengths that either match or come within a constant factor of the lower bounds.
On the degree of Boolean functions as real polynomials
Authors: Noam Nisan, Mario Szegedy
Venue: Proceedings of the twenty-fourth annual ACM symposium on Theory of computing (1992)

Every boolean function may be represented as a real polynomial. In this paper we characterize the degree of this polynomial in terms of certain combinatorial properties of the boolean function. Our first result is a tight lower bound of &OHgr;(log n) on the degree needed to represent any boolean function that depends on n variables. Our second result states that for every boolean function f the following measures are all polynomially related:(1) The decision tree complexity of f. (2) The degree of the polynomial representing f. (3) The smallest degree of a polynomial approximating f in the Lmax norm.
An analysis of Atkinson's algorithm
Authors: Greg Butler
Venue: ACM SIGSAM Bulletin (1992)

An algorithm for computing a minimal invariant partition of a permutation group due to Atkinson is analysed. The analysis shows the algorithm is O(n2), where n is the degree of the group. The leading coefficient is 3/2. Some suggested speed-ups are also analysed. The speed-ups imply that the cost of testing primitivity is O(n3), with a leading coefficent of 19/16.Careful use of linked lists to represent subsets of the partition leads to an O(nlogn) algorithm for computing a minimal invariant partition, and an O(n2 logn) algorithm for testing primitivity. For both algorithms, the leading coefficient is 1.The use of trees to represent subsets, and the technique of path compression, lead to an O(nG(n)|S|) algorithm, where S is the set of generators for the group, and G(n) is a very slow growing function related to Ackermann's function, for computing the minimal invariant partition. The leading coefficient is such that, for degrees less than 1,000,000, the linked list version gives a smaller bound.
Perspectives on CASE tool integration
Authors: Nicholas Wybolt
Venue: ACM SIGSOFT Software Engineering Notes (1991)

CASE tool integration means making the whole tool environment greater than the sum of its constituent parts (tools). An integrated CASE environment, in turn, is built on an integration framework. This paper presents a series of perspectives on CASE tool integration and frameworks.
Query optimization for parallel execution
Authors: Sumit Ganguly, Waqar Hasan, Ravi Krishnamurthy
Venue: Proceedings of the 1992 ACM SIGMOD international conference on Management of data (1992)

The decreasing cost of computing makes it economically viable to reduce the response time of decision support queries by using parallel execution to exploit inexpensive resources. This goal poses the following query optimization problem: Minimize response time subject to constraints on throughput, which we motivate as the dual of the traditional DBMS problem. We address this novel problem in the context of Select-Project-Join queries by extending the execution space, cost model and search algorithm that are widely used in commercial DBMSs. We incorporate the sources and deterrents of parallelism in the traditional execution space. We show that a cost model can predict response time while accounting for the new aspects due to parallelism. We observe that the response time optimization metric violates a fundamental assumption in the dynamic programming algorithm that is the linchpin in the optimizers of most commercial DBMSs. We extend dynamic programming and show how optimization metrics which correctly predict response time may be designed.
Project Athena as a Distributed Computer System
Authors: George A. Champine, Daniel E. Geer,  Jr., William N. Ruh
Venue: Computer (1990)

Project Athena, established in 1983 to improve the quality of education at MIT (Massachussetts Institute of Technology) by providing campuswide, high-quality computing based on a large network of workstations, is discussed, focusing on the design of Athena's distributed workstation system. The requirements of the system are outlined distributed system models are reviewed, other distributed operating systems are described, and issues in distributed systems are examined. The distributed-system model for Athena is discussed. Athena has three major components; workstations a network, and servers. The approach taken by the Athena developers was to implement a set of network services to replace equivalent time-sharing services, in essence converting the time-sharing Unix model into a distributed operating system.
The benefits of enumerated types in Modula-2
Authors: Mark Cashman
Venue: ACM SIGPLAN Notices (1991)

This paper shows that, contrary to [Lins90], enumerations are helpful to type safety in trongly-typed programming languages, such as Modula-2.
Rough Grammar for Efficient and Fault-Tolerant Computing on a Distributed System
Authors: Zbigniew M. Wójcik, Barbara E. Wójcik
Venue: IEEE Transactions on Software Engineering (1991)

A method that combines global load balancing with dynamic task scheduling on a multiprocessor machine is presented. This method does not require prior knowledge of the run times of tasks, and is based on a rough grammar representing distributed computation is presented. Production rules are dynamically constructed when a concurrent program is run. The set of the rough grammar production rules is updated and rolled in a pipeline fashion, together with codes of the processes. This pipeline fashion of rolling the jobs defines the global job balancing. The rough grammar uses any operators and metrics, not only concatenation, inside its production rules. Performance parameters for the combination of a global load balancing and decentralized dynamic task scheduling are derived and compared with those for a statically scheduled multiprocessor. Based on these parameters, the decentralized methodology is shown to attain a much higher performance level and a highly improved fault tolerance.
The p-shovelers problem: (computing with time-varying data)
Authors: Fabrizio Luccio, Linda Pagli
Venue: ACM SIGACT News (1992)

In a winter morning one man shovels the snow from his driveway. When the job is finished he can get out with the car. In the neighbouring driveway p men remove the same amount of snow in one p-th of time. The next morning is snowy. As the single shoveler goes on, new snow falls making his job harder. The neighbouring shovelers work for a shorter time, and a smaller amount of snow falls meanwhile, so that they clean the driveway in less than one p-th of time. This seems to conflict with a folklore theorem on parallel speed-up.
Composite Programs: Hierarchical Construction, Circularity, and Deadlocks
Authors: Waleed A. Muhanna
Venue: IEEE Transactions on Software Engineering (1991)

A graph-oriented, nonprocedural development environment in which composite programs are constructed by coupling a collection of existing component programs, the interfaces of which are defined by a fixed number of input ports and output ports, is discussed. It is shown that when the coupling graph is cyclic there is the possibility of a deadlock. A system that permits hierarchical construction of programs while testing, using a simple algebraic procedure, the resulting composite programs for communication deadlocks is presented. A decomposition-based approach to cycle enumeration is described. A formal graph-theoretic model of communication behavior for a class of atomic programs is presented. The model is then used to derive necessary and sufficient conditions for a deadlock to arise in a cycle. Techniques for dealing with deadly cycles (once identified) and improving the efficiency of their execution, once the cycles have been resolved, are described.
Dynamic 3D Models with Local and Global Deformations: Deformable Superquadrics
Authors: Demetri Terzopoulos, Dimitri Metaxas
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

The authors present a physically based approach to fitting complex three-dimensional shapes using a novel class of dynamic models that can deform both locally and globally. They formulate the deformable superquadrics which incorporate the global shape parameters of a conventional superellipsoid with the local degrees of freedom of a spline. The model's six global deformational degrees of freedom capture gross shape features from visual data and provide salient part descriptors for efficient indexing into a database of stored models. The local deformation parameters reconstruct the details of complex shapes that the global abstraction misses. The equations of motion which govern the behavior of deformable superquadrics make them responsive to externally applied forces. The authors fit models to visual data by transforming the data into forces and simulating the equations of motion through time to adjust the translational, rotational, and deformational degrees of freedom of the models. Model fitting experiments involving 2D monocular image data and 3D range data are presented.
Multi-valued logic and Gröner bases with applications to modal logic
Authors: J. Chazarain, A. Riscos, J. A. Alonso, E. Briales
Venue: Journal of Symbolic Computation (1991)

In the case of classical logic, the Stone isomorphism between Boolean Algebras and Boolean Rings is at the basis of the methods which reduce a logical problem to an algebraic one about polynomials. In this paper, we generalize this kind of reduction to the case of any multi-valued logic. Our main result is the Theorem 4.4 which transforms a deduction problem in a multi-valued logic to an equivalent problem about ideal membership in a polynomial ring. We give some examples of applications; for instance we detail the case of Lukasiewicz's modal logic.
Automatic Derivation of Formal Software Specifications from Informal Descriptions
Authors: Kanth Miriyala, Mehdi T. Harandi
Venue: IEEE Transactions on Software Engineering (1991)

SPECIFIER, an interactive system which derives formal specifications of data types and programs from their informal descriptions, is described. The process of deriving formal specifications is viewed as a problem-solving process. The system uses common problem-solving techniques such as schemas, analogy, and difference-based reasoning to derive formal specifications. If an informal description is a commonly occurring operation for which the system has a schema, then the formal specification is derived by instantiating the schema. If there is a no such schema, SPECIFIER tries to find a previously solved problem which is analogous to the current problem. If the problem found is directly analogous to the current problem, it applies an analogy mapping to obtain a formal specification. On the other hand, if the analogy found is only approximate, it solves the directly analogous part of the problem by analogy and performs difference-based reasoning using the remaining (unmatched) parts to transform the formal specification obtained by analogy to a formal specification for the entire original problem.
Performance of the HARRIS RTX 2000 Stack Architecture versus the Sun 4 SPARC and the Sun 3 M68020 Architectures
Authors: William F. Keown,  Jr., Philip Koopman,  Jr., Aaron Collins
Venue: ACM SIGARCH Computer Architecture News (1992)

This study compares a stack machine, the Harris RTX 2000, a RISC machine, the Sun 4/SPARC, and a CISC machine, the Sun3/M68020. An attempt is made to compare the generic features of each machine which are characteristic of their architectural classes as opposed to being characteristic of the individual machine only. Performance is compared based on execution of the Stanford Integer Benchmark series (12) and on interrupt response characteristics. The data indicates that, for these benchmarks, the RTX stack architecture approaches or exceeds the SPARC machine performance for such measures as total execution cycles required, clock cycles per instruction, native MIPS, static code size, and dynamic instruction count. The 68020 machine is by far the slowest of the three. When scaled to account for disparities in process technology, the RTX 2000 is as fast as (or faster than) the SPARC in actual program execution time, and it has a smaller code size.
Distributed multicasting algorithm in a wide area network
Authors: Anna Hac
Venue: Proceedings of the 1990 ACM annual conference on Cooperation (1990)

This paper proposes a new multicasting algorithm that allows for message transfer from the source to the multicasting destination by using routing in the source. The routing algorithm uses a tree of trunks and nodes from the source to the multicasting destination. The bounds on the trunks and nodes occupancy are used to balance the occupancy of the trunks and nodes. The bounds on the number of trunks and nodes in the tree limit the number of paths considered by the algorithm. The message transfer time is calculated and the path with the shortest transfer time is chosen. The multicasting algorithm performance is analyzed by using the elapsed time of message transfer in the network and the waiting time to begin transfer in the nodes.
Exploiting multi-way branching to boost superscalar processor performance
Authors: Yen-Jen Oyang
Venue: ACM SIGPLAN Notices (1991)

This paper discusses exploiting multi-way branching to boost superscalar processor performance. The exploitation of multi-way branching contributes to a boost in superscalar processor performance through two effects: (1) increase of instruction-level parallelism and (2) reducing of the amount of branch penalty. The work presented in this paper comprises two conjunctive parts. The first part is a compiler technique called the SV (Shadow Variable) transformation. The second part is a new multi-way branching scheme developed in conjunction with the SV transformation. The SV transformation can transform program segments which multi-way branching is originally not applicable to into ones which multi-way branching is applicable to. The proposed multi-way branching scheme, meanwhile, is able to carry out multi-way branches efficiently, especially for those derived from applying the SV transformation, and requires no expensive hardware for implementation.
Incremental clustering for dynamic information processing
Authors: Fazli Can
Venue: ACM Transactions on Information Systems (TOIS) (1993)

Clustering of very large document databases is useful for both searching and browsing. The periodic updating of clusters is required due to the dynamic nature of databases. An algorithm for incremental clustering is introduced. The complexity and cost analysis of the algorithm together with an investigation of its expected behavior are presented. Through empirical testing it is shown that the algorithm achieves cost effectiveness and generates statistically valid clusters that are compatible with those of reclustering. The experimental evidence shows that the algorithm creates an effective and efficient retrieval environment.
A workshop on computer graphics for undergraduate faculty
Authors: G. Scott Owen, Valerie A. Miller
Venue: ACM SIGGRAPH Computer Graphics (1991)

A week long workshop in computer graphics, co-sponsored by Georgia State University (GSU) and the National Science Foundation (NSF grant No. USE-8954402 ) was held at GSU August 20-24,1990. The twenty four participants in the workshop were faculty from undergraduate institutions and the instructors were the authors of this paper. In the following we will describe the demographics of the faculty group, the subject areas covered, the format of the workshop, the developed course materials, and the results. This workshop can possibly be used as the prototype for future such workshops.
Analysis of shortest-path routing algorithms in a dynamic network environment
Authors: Zheng Wang, Jon Crowcroft
Venue: ACM SIGCOMM Computer Communication Review (1992)

In a dynamic network environment under heavy traffic load, shortest-path routing algorithms, particularly those that attempt to adapt to traffic changes, frequently exhibit oscillatory behaviors and cause performance degradation. In this paper we first examine the problems from the perspective of control theory and decision making, and then analyze the behaviors of the shortest-path routing algorithms in details.