ppxscal/embedding_network huggingface dataset:
Group communication in multichannel networks with staircase interconnection topologies
Authors: P. K. McKinley, J. W. S. Liu
Venue: ACM SIGCOMM Computer Communication Review (1989)

Recently, multichannel networks composed of several parallel, medium-speed channels multiplexed on a single high-speed medium have been proposed as a practical way to harness the high bandwidths of optical fibers. In order to limit the cost of network interfaces, a partially-connected multichannel network allows each node access to only a proper subset of the channels, its channel set. Staircase interconnection topologies constitute a family of partially-connected multichannel networks in which every node can still send messages directly to every other node. Group-based computer applications composed of cooperative processing entities are proliferating. The communication among processes in group-based applications typically involves multiple destinations and is often symmetric and temporally local. In this paper, we investigate the problem of supporting group communication in staircase multichannel networks. We analyze those properties of staircase topologies that benefit temporally local multicast communication. We then develop an adaptive protocol that permits nodes to dynamically change their channel sets. These changes are based on recent network traffic history, thus enabling the topology to conform to network traffic patterns and, specifically, group locality. Analytical and simulation results are presented.
A vision of education in user-centered system and interface design
Authors: R. Baecker
Venue: ACM SIGCHI Bulletin (1989)

This paper outlines a proposal for a new curriculum in human-computer interaction and user-centered system and interface design that is intended to be based within a computer science departmental framework. The intellectual foundations and political assumptions underlying the curriculum are described. A preliminary list of course offerings and requirements for a B.Sc. degree is presented.
Internet routing
Authors: T. Narten
Venue: Symposium proceedings on Communications architectures protocols (1989)

Comprising an estimated 60,000 hosts, the DARPA Internet is the largest existing internet. This paper traces the routing information protocols used by Internet gateways to build routing tables that define the paths datagrams traverse as they travel between end systems. We articulate the weaknesses and limitations of the most commonly used routing protocols, including RIP, GGP, and HELLO and examine how the protocols interact with each other and with EGP. Finally, we trace the evolution of routing as the Internet has grown from a single backbone (ARPANET) to its present inclusion of the ARPANET, Milnet, and NSFnet cross-country networks.
Contexts and metamessages in object-oriented database programming language design
Authors: Michael Caruso Edward Sciore
Venue: Proceedings of the 1988 ACM SIGMOD international conference on Management of data (1988)

VISION is an object-oriented database system currently used commercially to develop investment analysis and other large statistical applications. Characteristic of these applications, beside the standard issues of structural and computational richness, is the need to handle time, versions, and concurrency control in a manner that does not produce combinatoric complexity in object protocol. This paper describes the approach taken by VISION in addressing these issues.
Optimization techniques for symbolic equation solver in engineering applications
Authors: H. Q. Tan, X. Dong
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

In MACYSMA, there are procedures for solving systems of equation, such as solve and linsolve. Because the systems of equations we are dealing with are mostly sparse, the application of Gaussian elimination which is used in linsolve produces results that are usually lengthy and inefficient. We have implemented a new derivation procedure to solve the problem of expression growth and increasing the computational efficiency. The underlying concept is the identification of the smallest full subsystems contained within the original and then subsequent remaining systems, labeling common terms by intermediate variables. Gaussian elimination is employed to solve these subsystems independently and sequentially instead of the complete system.
On factoring multi-variate polynomials over algebraically closed fields (abstract)
Authors: K. Yokoyama, M. Noro, T. Takeshima
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

For a problem how to find an extension field over which we can obtain an absolutely irreducible factor, Kaltofen gave an answer in 1983 and explicitly in 1985 by employing analytic argument for showing his answer, and Chistov and Grigor'ev also gave the same answer in 1983 by algebraic arguments. Here, we give an alternative proof for Kaltofen's answer in algebraic way, independently to Chistov and Grigor'ev, and by the benefit of new way, we also give several extensions of his answer and properties of absolutely irreducible factors. We also discuss usage of our results for actual computation of absolutely irreducible factors. Here we restrict ourselves to bi-variate polynomials with integer (or rational) coefficients. First we state Kaltofen's answer. Kaltofen's theorem. For a bi-variate monic polynomial &fnof;(x, y) with integer coefficients, if &fnof;(x, a) is square free for an integer a, then we can get an irreducible factor of &fnof;(x, y) over the algebraic closure of Q by factoring &fnof;(x, y) over an algebraic extension field containing a root of &fnof;(x, a). Our main results are the following: We give an alternative proof of Kaltofen's theorem by using the fact that for a bi-variate polynomial &fnof;(x, y) irreducible over Q, all its absolutely irreducible factors are conjugate with each other and the set of all roots of each irreducible factor becomes an imprimitive block of the action of the Galois group of &fnof;(x, y). We specialize the theorem to several coefficient domains such as fields with non zero characteristic. By employing the argument used for an alternative proof, we obtain several useful properties of absolutely irreducible factors, from which we can present several quick test for absolute irreducibility of &fnof;(x, y) and information of the degree partition of &fnof;(x, y) relating to the degree partition of &fnof;(x, a), where a is an integer. We apply the property, information of the degree partition, obtained in (3) to improve existing algorithms for absolute factoring. Thus, our further study on the problem in algebraic way provides several improvements on existing algorithms for factoring multi-variate polynomials.
An Incremental Version of Iterative Data Flow Analysis
Authors: L. L. Pollock, M. L. Soffa
Venue: IEEE Transactions on Software Engineering (1989)

A technique is presented for incrementally updating solutions to both union and intersection data-flow problems in response to program edits and transformations. For generality, the technique is based on the iterative approach to computing data-flow information. The authors show that for both union and intersection problems, some changes can be incrementally incorporated immediately into the data-flow sets while others are handled by a two-phase approach. The first phase updates the data-flow sets to overestimate the effect of the program change, enabling the second phase to incrementally update the affected data-flow sets to reflect the actual program change. An important problem that is addressed is the computation of the data-flow changes that need to be propagated throughout a program, based on different local code changes. The technique is compared to other approaches to incremental data-flow analysis.
Inside RISKS: risks in medical electronics
Authors: Jonathan Jacky
Venue: Communications of the ACM (1990)

The RISKS Forum has had many accounts of annoying errors, expensive breakdowns, privacy abuses, security breaches, and potential safety hazards. However, postings describing documented serious injuries or deaths that scan be unequivocally attributed to deficiencies in the design or implementation of computer-controlled systems are very rare. A tragic exception was a series of accidents which occurred between 1985 and 1987 involving a computer-controlled radiation therapy machine.
A prolog simulation for a Delphi-based problem solver
Authors: Adel S. Elmaghraby
Venue: ACM SIGSIM Simulation Digest (1988)

Expert systems model human beings in problem solving. This paper presents an approach for building distributed expert systems, modelled after human group decision making. The Delphi technique for group decision making has been used to present two alternative approaches. A solution integration approach and a model integration approach are discussed. A Prolog simulation of the Delphi problem solver demonstrates these concepts.
A dynamic constraint-directed ordered search algorithm for solving constraint satisfaction problems
Authors: Wesley W. Chu, Patrick Ngai
Venue: Proceedings of the 1st international conference on Industrial and engineering applications of artificial intelligence and expert systems - Volume 1 (1988)

Many engineering problems such as Job Shop Scheduling can be categorized as constraint satisfaction problems. We propose the Dynamic Constraint-directed Ordered Search (DCOS) to solve such problems. DCOS repeatedly re-arranges the search order of the variables and eliminates its local inconsistencies by using a low order network consistency algorithm. As a result, it reduces the width of the search tree. The reduction of the width of the search tree causes the decrease in the number of backtrackings required to find the solution. We have applied DCOS to the Graph Coloring Problem and the Zebra Problem with a second order network consistency algorithm and obtained almost-backtrack-free searches for both cases.
Algorithms and proofs: mathematics in the computing curriculum
Authors: Newcomb Greenleaf
Venue: Proceedings of the twentieth SIGCSE technical symposium on Computer science education (1989)

Computing has supplied mathematics with a new vocabulary of algorithms and is holding out the promise that mathematics can be implemented. Algorithms and proofs can now be seen as the same type of object. This new vision of mathematics as a very high level programming language suggests that mathematics may be transformed so that it is more in harmony with the spirit of computing, and has profound implications for the way in which mathematics is taught. Such harmony would be particularly beneficial for students of computing, who often find little of relevance in their mathematics courses.
Expanding graphs and the average-case analysis of algorithms for matchings and related problems
Authors: R. Motwani
Venue: Proceedings of the twenty-first annual ACM symposium on Theory of computing (1989)

Hall's Theorem states that a bipartite graph has a perfect matching if and only if every set of vertices has an equal number of neighbours. Equivalently, it states that every non-maximum matching has an augmenting path if the graph is an expander with expansion 1. We use this insight to demonstrate that if a graph is an expander with expansion more than one than every non-maximum matching has a short augmenting path and, therefore, the bipartite matching algorithm performs much better on such graphs than in the worst case. We then apply this idea to the average case analysis of various augmenting path algorithms and to the approximation of the permanent. In particular, we demonstrate that the following algorithms perform much better on the average than in the worst case. In fact, they will rarely exhibit their worst-case running times. Hopcroft-Karp's algorithm for bipartite matchings. Micali-Vazirani's and Even-Kariv's algorithms for non-bipartite matchings. Gabow-Tarjan's parallel algorithm for bipartite matchings. Dinic's algorithm for k-factors and 0-1 network flows. Jerrum-Sinclair's approximation scheme for the permanent. It seems rather surprising that the algorithms which are the fastest known for worst-case inputs also do exceedingly on almost every graph.
Task migration in hypercube multiprocessors
Authors: M.-S. Chen, K. G. Shin
Venue: ACM SIGARCH Computer Architecture News (1989)

Allocation and deallocation of subcubes usually result in a fragmented hypercube where even if a sufficient number of hypercube nodes are available, they do not form a subcube large enough to execute an incoming task. As the fragmentation in conventional memory allocation can be handled by memory compaction, the fragmentation problem in a hypercube can be solved by task migration, i.e., relocating tasks within the hypercube to remove the fragmentation. The procedure for task migration closely depends on the subcube allocation strategy used, since active tasks must be relocated in such a way that the availability of subcubes can be detected by that allocation strategy. In this paper, we develop a task migration strategy for the subcube allocation policy based on the binary reflected Gray code. A goal configuration (of destination subcubes) without fragmentation is determined first. Then, the node-mapping between the source and destination subcubes is derived. Finally, a routing procedure to achieve shortest deadlock-free paths for relocating tasks is developed.
A relationship between abstract interpretation and projection analysis
Authors: Geoffrey Burn
Venue: Proceedings of the 17th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1989)

Abstract interpretation and projection analysis are two techniques for finding out information about lazy functional programs. Two typical uses of these techniques are speeding up sequential implementations, and the introduction of parallelism into parallel implementations. Our main result is the proof of a relationship between a certain class of projections and a certain class of abstract interpretations. One of the claims of projection analysis is that it can find out information about head-strictness, whilst abstract interpretation cannot. We show that there are at least two intuitive notions of head-strictness, and that one of them can be determined using abstract interpretation.
An evaluation tool for measuring authoring system performance
Authors: Carol B. MacKnight, Santosh Balagopalan
Venue: Communications of the ACM (1989)

A model for producing objective and precise measurements of the power and performance of authoring systems is described. An animation task is given as an example of the model's potential as a tool for evaluating authoring systems along the dimensions of functionality, flexibility, and productivity.
Data communications teams: the best of both worlds
Authors: J. Lawson
Venue: Proceedings of the 17th annual ACM SIGUCCS conference on User Services (1989)

Computer Centers and Communications Departments (campus telephone people) are having to work more and more together because of the increased amount of computing and networking equipment found in today's campuses. Furthermore, the lines between what is a computer and what is a telephone are getting very blurred as technology becomes more sophisticated. It is getting to the point where day-to-day problems are handled by both groups, sometimes with undesirable finger pointing and &ldquo;left hand versus right hand&rdquo; lack of coordination. This paper will discuss the importance of and steps towards creating a Data Communications Team (DCT). This team ideally consists of software and hardware &ldquo;gurus&rdquo; from the computer center, as well as equipment and physical plant technologists from the communications department. Problems and solutions can be identified and resolved in a more efficient and coordinated fashion, and the team's ability to present a &ldquo;United Front&rdquo; when dealing with the users cannot be ignored. UAB is currently assembling their DCT, and this paper will also include initial results, adjustments, and hints for others wanting to develop their own team.
Parallel Random Number Generation for VLSI Systems Using Cellular Automata
Authors: P. D. Hortensius, R. D. McLeod, H. C. Card
Venue: IEEE Transactions on Computers (1989)

A novel random number generation (RNG) architecture of particular importance in VLSI for fine-grained parallel processing is proposed. It is demonstrated that efficient parallel pseudorandom sequence generation can be accomplished using certain elementary one-dimensional cellular automata (two binary states per site and only nearest-neighbor connections). The pseudorandom numbers appear in parallel from various cells in the cellular automaton on each clock cycle and pass standard empirical random number tests. Applications have been demonstrated in the design and analysis of special-purpose accelerators for Monte Carlo simulation of large intractable systems. In addition, significant advantages in pseudorandom built-in self-test of VLSI circuits using cellular automata based RNGs have been demonstrated.
Inferring sequences produced by pseudo-random number generators
Authors: Joan Boyar
Venue: Journal of the ACM (JACM) (1989)

In this paper, efficient algorithms are given for inferring sequences produced by certain pseudo-random number generators. The generators considered are all of the form Xn = &Sgr;kj-l &agr;j&phgr;j(Xo, Xl, . . ., Xn-l) (mod m). In each case, we assume that the functions &phgr;j are known and polynomial time computable, but that the coefficients aj and the modulus m are unknown. Using this general method, specific examples of generators having this form, the linear congruential method, linear congruences with n terms in the recurrence, and quadratic congruences are shown to be cryptographically insecure.
Efficient management of transitive relationships in large data and knowledge bases
Authors: R. Agrawal, A. Borgida, H. V. Jagadish
Venue: Proceedings of the 1989 ACM SIGMOD international conference on Management of data (1989)

We argue that accessing the transitive closure of relationships is an important component of both databases and knowledge representation systems in Artificial Intelligence. The demands for efficient access and management of large relationships motivate the need for explicitly storing the transitive closure in a compressed and local way, while allowing updates to the base relation to be propagated incrementally. We present a transitive closure compression technique, based on labeling spanning trees with numeric intervals, and provide both analytical and empirical evidence of its efficacy, including a proof of optimality.
A self-service PC-LAN-or-how many ways are there to insert a diskette in a drive?
Authors: Alan Federman
Venue: Proceedings of the 16th annual ACM SIGUCCS Conference on User Services (1988)

Indiana University - Purdue University at Fort Wayne has established a self-service PC-LAN for use by faculty, students, and staff. The cluster consists of 15 IBM PS/2 Model 30's, 6 IBM XT's, and two IBM Proprinters. The machines all have IBM token ring cards with auto-boot ROMs from Novell. As in most public institutions, it is much easier to get funding for equipment than it is for personnel. We simply do not have the staff to check-out diskettes. The PC's are connected to a AT type server running Novell Netware. The auto-boot feature eliminates the need to supply boot disks. A student can come in at anytime to do a class assignment or word processing. The server truly is just that; it dishes out the software to the user via a menu. Students who wish to save data must use their own diskettes. Currently, all software selection is accomplished through Novell's &ldquo;point and shoot&rdquo; menuing system. A rich variety of software is available, including commercial applications, shareware, instructor developed programs, tutorials, demonstrations, and packages developed by various academic consortia. Our commercial applications include Lotus, WordPerfect and WordStar. Shareware programs include PC-Write, Express-Calc, File-Express and Express-Graph. The difficulties with hardware and software have been minor. Some programs, which run well in a stand-alone mode, do not work well on a network. This is especially true of programs which load their own DOS shell. Other programs, some advertised as network versions, were less than satisfactory. The hardware has been relatively trouble free. Two power supplies and one cable were replaced. The most significant problems concerned inadequate training. The cluster is designed to be self-documenting and easy to use. There are on-line tutorials that cover DOS, word processing, spreadsheets, etc. Manuals for all the popular software are located in racks in the room. Despite this, many people come into to the cluster (having been given a class assignment by an instructor) without the faintest idea how to proceed. Very few instructors have visited the cluster or discussed its use before unleashing their students. We underestimated the amount of hand-holding that this group would need. We also badly underestimated the volume of printing produced.
A suppport strategy for users of a campus-wide local area network
Authors: Stphen M. Poltz, Scott W. Smith, David W. Ballowe
Venue: Proceedings of the 16th annual ACM SIGUCCS Conference on User Services (1988)

At the time of the network's purchase, the University had no centralized data communications organization. Responsibilities of the network were divided between two departments, the Data Communications group at Academic Computing Services (ACS) and Voice and Data Telecommunications. ACS provided the system administration and user support while Telecommunications had physical control and performed the business duties. This dualistic approach to running the network created an environment of confusion for the user community. Not only were the missions of the two departments different, but each were part of different branches of the university organization, reporting to different vice chancellors.
Symbolic evaluation of integrals occurring in accelerator orbit theory
Authors: B. Autin, J. Bengtsson
Venue: Journal of Symbolic Computation (1989)

Definite integrals which appear in the perturbation theory of a particle's transverse oscillations and chromatic aberrations inside an accelerator are evaluated by symbolic computation. The symbolic program and the automatic FORTRAN coding of the generated functions are described. The results are checked by comparison with those obtained by direct numerical integration. It turns out that, once having established the FORTRAN function subprograms symbolically, their use for different parameters requires much less time than direct numerical integration.
Integrated scheduling and binding: a synthesis approach for design space exploration
Authors: M. Balakrishnan, P. Marwedel
Venue: Proceedings of the 26th ACM/IEEE Design Automation Conference (1989)

Synthesis of digital systems, involves a number of tasks ranging from scheduling to generating interconnections. The interrelationship between these tasks implies that good designs can only be generated by considering the overall impact of a design decision. The approach presented in this paper provides a framework for integrating scheduling decisions with binding decisions. The methodology supports allocation of a wider mix of operator modules and covers the design space more effectively. The process itself can be described as incremental synthesis and is thus well-suited for applications involving partial pre-synthesized structures.