ppxscal/embedding_network huggingface dataset:
Whistle: A Workbench for Test Development of Library-Based Designs
Authors: Raphael Renous, Gabriel M. Silberman, Ilan Spillinger
Venue: Computer (1989)

The authors have applied the difference fault model (DFM) approach to the simulation of high-level designs and built a complete environment for test generation and fault simulation of designs expressed in a hardware description language (HDL), such as VHDL. Their environment, called Whistle, consists of a set of programs that supports a library-based design style. They describe the tools in Whistle, with special emphasis on the tools used to analyze each block in the design library, and the generation of code for the simulation of the F-faults in the design. The authors then evaluate Whistle from several points of view. First, they illustrate the accuracy of the fault coverage estimates by comparing them with the actual fault coverage obtained by gate-level fault simulation. Second, they examine the correlation between the accuracy measurements as given by their evaluation functions and the behavior of various characterization functions for a given block. This illustrates how critical it is to choose a good characterization function and how it affects the accuracy of the results. A third aspect of Whistle that they look at is its test-generation capability.
An O(NlogN) hypercube N-body integrator
Authors: M. Warren, J. Salmon
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

The gravitational N-body algorithm of Barnes and Hut [1] has been successfully implemented on a hypercube concurrent processor. The novel approach of their sequential algorithm has demonstrated itself to be well suited to hypercube architectures. The sequential code achieves O (NlogN) speed by recursively dividing space into subcells, thereby creating a hierarchical grouping of particles. Computing interactions between these groups dramatically reduces the amount of communication between processors, as well as the number of force calculations. Parallelism is achieved through an irregular spatial grid decomposition. Since the decomposition topology is not simple, a general loosely synchronous communication routine has been developed. Operations are simplified if the conventional grey code decomposition is modified so that the bits are taken alternately from each Cartesian dimension. A speedup of 180 has been achieved for a 500,000 particle two-dimensional calculation on 256 processors. A speedup of 65 has been obtained for a 64,000 particle three-dimensional calculation on 256 processors.
The Crossover Net LAN System Using an Intelligent Head-End
Authors: S. Saito, H. Yoshida, T. L. Kunii
Venue: IEEE Transactions on Computers (1989)

The development of a multimedia broadband local area network (LAN) system named CrossoverNet using a intelligent head-end is presented. This head-end provides two-way digital/analog communication with dynamic channel exchange and network configuration control. Based on these functions, the head-end exchanges analog information in a manner similar to digital circuit exchange. Digital and analog information are transmitted separately over the same broadband cable and integrated in audiovisual protocol layers. To provide these facilities, a LAN architecture conforming to the Open Systems Interconnection (OSI) basic reference model is designed using broadband and CATV network technologies. The result, CrossoverNet, can control, operate, and manage a variety of audiovisual devices that are attached to it in a consistent manner. A prototype experiment illustrates the versatility of the system.
Hypertext, full text, and automatic linking
Authors: J. H. Coombs
Venue: Proceedings of the 13th annual international ACM SIGIR conference on Research and development in information retrieval (1989)

Current computing systems typically support only mid-century information structures: simple hierarchies. Hypertext technologies enable users to impose many structures on document sets and, consequently, provide many paths to desired information, but they require that users work their way through some structure. Full-text search eliminates this requirement by ignoring structure altogether. The search strategy can also be restricted to work within specified contexts. The architecture provided for search readily supports automatic linking. These ideas have been tested in IRIS Intermedia.
Multiple-Way Network Partitioning
Authors: L. A. Sanchis
Venue: IEEE Transactions on Computers (1989)

A multiple-block network partitioning algorithm adapted from a two-block iterative improvement partitioning algorithm is presented. This adaptation of the algorithm and of the level gain concept to multiple blocks seeks to improve the partition uniformly with respect to all blocks as oppose to making repeated uses of two-way partitioning. Appropriate data structures and a complexity analysis are presented, as well as experimental results. The experiments indicate that the optimal number of levels to use depends on the number of blocks and the net size and degree distributions of the network, but it varies little with the size of the network. In particular, higher levels are increasingly useful as the number of blocks in the partition increases. Theoretical results agree with the experimental results and form the basis for a predictor which, given a network and the desired number of blocks, approximates the optimal number of levels.
Equivalence Between Functionality and Topology of Log N-Stage Banyan Networks
Authors: A. Youssef, B. W. Arden
Venue: IEEE Transactions on Computers (1990)

Existing procedures to decide network equivalence in log N-stage banyan networks are based on analysis of permutations, take polynomial but costly time, and do not shed light on or take advantage of the relationship between functionality and topology. This relationship is addressed and it is shown that two log N-stage banyan networks of the same switch size are functionally equivalent if and only if they have the same underlying topology. An O(N log N) algorithm is derived which decides if two N-stage banyan networks of N inputs, N outputs, and r*r crossbar switches as building blocks realize the same permutations. The algorithm works by comparing the underlying topologies of the two networks. The algorithm is optimal because the size of the networks is O(N log N).
Formal Verification of Fault Tolerance Using Theorem-Proving Techniques
Authors: J. Kljaich,  Jr., B. T. Smith, A. S. Wojcik
Venue: IEEE Transactions on Computers (1989)

A formal verification system based on the use of automated reasoning techniques is described to validate fault tolerance. An extended Petri net representation, called a flow net, is described together with the theorem-proving implementation of a rule-based system for manipulating system descriptions. Examples taken from the literature are used to illustrate the representation and the capabilities of the formal verification system under development.
Using rewriting techniques to solve the generalized word problem in polycyclic groups
Authors: J. Avenhaus, D. Wi:Gbmann
Venue: Proceedings of the ACM-SIGSAM 1989 international symposium on Symbolic and algebraic computation (1989)

In this paper we apply rewriting techniques to the generalized word problem GWP in polycyclic groups. We assume the group G to be given by a canonical polycyclic string-rewriting system R and consider GWP in G which is defined by GWP(w,U) iff w&isin; <U> for w&isin; G, finite U&sube;G, where <U> is the subgroup of G generated by U. We describe <U> also by a rewrite system S and define a rewrite relation @@@@S,R in such a way that w @@@@S,R &lgr; iff w&isin; <U> (&lgr; the empty word). For this rewrite relation we develop different critical pair criteria for @@@@S,R to be &lgr;-confluent, i.e. confluent on the left-congruence class [&lgr;] of @@@@S,R. Using any of these &lgr;-confluence criteria we construct a completion procedure which stops for every input S and computes a &lgr;-confluent rewrite system equivalent to S. This leads to a decision procedure for GWP in G. Thus we give an explicit uniform algorithm for deciding GWP in polycyclic groups and a new proof based almost only on rewriting techniques for the decidability of this problem. Further, we define a rewrite relation @@@@LM,U which is stronger than @@@@S,R. We show that if G is given by a nilpotent string-rewriting system, then by a completion procedure the input U can be transformed into V such that @@@@LM,V is even confluent, not just &lgr;-confluent.
Order-sorted unification
Authors: Jose Meseguer, Joseph A. Goguen
Venue: Journal of Symbolic Computation (1989)

This paper studies unification for order-sorted equational logic. This logic generalizes unsorted equational logic by allowing a partially ordered set of sorts, with the ordering interpreted as set-theoretic containment in the models; it also allows overloading of function symbols, such as + for integer and rational number addition, with the overloaded functions of greater rank interpreted in the models as extensions of those of smaller rank. Our presentation emphasizes semantic aspects, and gives a categorical treatment of unification that has substantial advantages in this context over the usual treatment of unifiers as endomorphisms of a single free algebra. Given system @C of equations and a set E of axioms that is sort-preserving and does not impose restrictions on the sorts of its variables, the main results characterize when an order-sorted signature has a minimal (or finite, or most general when @C is solvable) family of order-sorted E-unifiers for @C. In addition, for unitary signatures, where each solvable system of equations has a most general unifier, we give a quasi-linear algorithm for syntactic unification (i.e., for E= ) a la Martelli-Montanari, that is more efficient than the unsorted one for failures.
Forests, frames, and games: algorithms for matroid sums and applications
Authors: Harold Gabow, Herbert Westermann
Venue: Proceedings of the twentieth annual ACM symposium on Theory of computing (1988)

This paper presents improved algorithms for matroid partitioning problems, such as finding a maximum cardinality set of edges of a graph that can be partitioned into k forests. The notion of a clamp in a matroid sum is introduced. Efficient algorithms for problems involving clumps are presented. Applications of these algorithms to problems arising in the study of structural rigidity of graphs, the Shannon switching game and others are given.
Compiler-Directed Cache Management in Multiprocessors
Authors: Hoichi Cheong, Alexander V. Viedenbaum
Venue: Computer (1990)

The necessity of finding alternatives to hardware-based cache coherence strategies for large-scale multiprocessor systems is discussed. Three different software-based strategies sharing the same goals and general approach are presented. They consist of a simple invalidation approach, a fast selective invalidation scheme, and a version control scheme. The strategies are suitable for shared-memory multiprocessor systems with interconnection networks and a large number of processors. Results of trace driven simulations conducted on numerical benchmark routines to compare the performance of the three schemes are presented.
Transformation of Optical Flow by Camera Rotation
Authors: K. Kanatani
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

The effect of camera rotation on the description of optical flow generated by a planar surface in motion is treated. A transformation law for the parameters is given explicitly by analyzing infinitesimal generators and irreducibly reducing the induced representation of the 3-D rotation group SO(3). The parameter space is decomposed into invariant subspaces, and the optical flow resulting from planar surface motion is accordingly decomposed into two parts, from which an invariant basis is deduced. A procedure is presented to test the equivalence of two optical flows and to reconstruct the camera rotation. The relationship with the analytical expressions for 3-D recovery is discussed.
Incremental Distance and Diameter Sequences of a Graph: New Measures of Network Performance
Authors: V. Krishnamoorthy, K. Thulasiraman, M. N. S. Swamy
Venue: IEEE Transactions on Computers (1990)

Two new measures of network performance, namely, the incremental distance sequence and the incremental diameter sequence, are introduced for application in network topology design. These sequences can be defined for both vertex deletions and edge deletions. A complete characterization of the vertex-deleted incremental distance sequence is presented. Proof of this characterization is constructive in nature. A condition for the feasibility of an edge-deleted incremental distance sequence and a procedure for realizing such a sequence are given. Interrelationships between the elements of incremental distance sequences and incremental diameter sequences are studied. Using these results, it is shown that a graph that has a specified diameter and a specified maximum increase in diameters for deletions of vertex sets of given cardinalities can be designed.
Construction of the Octree Approximating a Three-Dimensional Object by Using Multiple Views
Authors: Hiroshi Noborio, Shozo Fukuda, Suguru Arimoto
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1988)

A fast, efficient, algorithm that processes polyhedral cones from views of an object to produce an octree representation of the object is proposed. A polyhedral cone defined by both a viewpoint and a polygonal contour of the object in the image for each view always contains the object. Thus the common region of the cones for multiple views is considered to be an approximating one of the object. The octree representation controls all cubic regions in three-dimensional space as a set of nodes with a hierarchical description in positioning, and therefore is suitable for registration of the common region. The computational complexity of the algorithm is directly proportional to the common region surface area and exponentially proportional to the finest resolution level of the octree. The calculation time of the algorithm is determined for illustrative examples of three-dimensional objects.
D.S.P.P.: a data security pipe protocol for PC's,large scale systems or networks
Authors: Daniel Guinier
Venue: ACM SIGSAC Review (1988)

D.S.P.P.: Data Security Pipe Protocol is an original asymetric cryptographic time dependent public auto-key protocol applied to data security. This protocol has been designed for secrecy in data files or end-to-end data communications and to solve problems involving intruders in networks or locally and also to avoid cheating by contractors ... in other words to answer the question:Is it possible for Michael and Fran ccedil;ois to communicate in perfect security without cheating each other and without interference from a 'third party' in the network ...even they are total strangers...? with respect with conviviality and simplicity for use !According to theoretical considerations on the most efficient methods of computing in multi-precision modular arithmetic, we use Mersenne primes of 521, 607 and potentially 1279 binary digits and a random generator of very large period claimed to be O (10174) which presents good statistical proprieties and recently developed by Guinier D. (1986). Auto-public keys are single because they are message-signature-day-time-dependent and change their values at each computer tick I This protocol is applied to digital signatures, notarification, data integrity and confidentiality. The actual implementation in structured Fortran 77 works on a personal computer PC/AT and could be used as well on large scale systems as on networks. Encryption-decryption rate on PC's is O (1000 characters per second) and public or communication keys are generated from 3 seconds to some minutes depending on the key length in use (127, 521, 607 or 1279-bit).
A highly integrated tool set for program development support
Authors: Gregor Engels, Thorsten Janning, Wilhelm Schäfer
Venue: Proceedings of the 1988 ACM SIGSMALL/PC symposium on ACTES (1988)

This paper describes the design of the integrated user interface of the software development environment IPSEN (Integrated Programming Support Environment). We explain the characteristic features of the IPSEN user interface, namely the structured layout of the screen, the command-driven tool activation, and especially the highly integrated use of the IPSEN tool set. We demonstrate those features by taking a sample set of tools of the IPSEN environment. That tool set supports all the programming-in-the-small activities within IPSEN. Finally, we sketch the realization of two prototypes running on an IBM-AT and a net of SUN workstations.
Recipes for geometry and numerical analysis - Part I: an empirical study
Authors: D. P. Dobkin, D. Silver
Venue: Proceedings of the fourth annual symposium on Computational geometry (1988)

Geometric computations, like all numerical procedures, are extremely prone to roundoff error. However, virtually none of the numerical analysis literature directly applies to geometric calculations. Even for line intersection, the most basic geometric operation, there is no robust and efficient algorithm. Compounding the difficulties, many geometric algorithms perform iterations of calculations reusing previously computed data. In this paper, we explore some of the main issues in geometric computations and the methods that have been proposed to handle roundoff errors. In particular, we focus on one method and apply it to a general iterative intersection problem. Our initial results seem promising and will hopefully lead to robust solutions for more complex problems of computational geometry.
Hypothetical datalog negation and linear recursion
Authors: A. J. Bonner
Venue: Proceedings of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1989)

This paper examines an extension of Horn logic in which rules can add entries to a database hypothetically. Several researchers have developed logical systems along these lines, but the complexity and expressibility of such logics is only now being explored. It has been shown, for instance, that the data-complexity of these logics is PSPACE-complete in the function-free, predicate case. This paper extends this line of research by developing syntactic restrictions with lower complexity. These restrictions are based on two ideas from Horn-clause logic: linear recursion and stratified negation. In particular, a notion of stratification is developed in which negation-as-failure alternates with linear recursion. The complexity of such rulebases depends on the number of layers of stratification. The result is a hierarchy of syntactic classes which corresponds exactly in the polynomial-time hierarchy of complexity classes. In particular, rulebases with k strata are data-complete for &Sgr;Ph. Furthermore, these rulebases provide a complete characterization of the relational queries in &Sgr;Ph. That is, any query whose graph is in &Sgr;Ph can be represented as a set of hypothetical rules with k strata. Unlike other expressibility results in the literature, this result does not require the data domain to be linearly ordered.
Constructing Submodule Specifications and Network Protocols
Authors: D. P. Sidhu, J. Aristizabal
Venue: IEEE Transactions on Software Engineering (1988)

Applications of an automated tool for module specification (ATMS) that finds the specification for a submodule of a system are presented. Given the specification of a system, together with the specification for n-1 submodules, the ATMS constructs the specification for the nth addition submodule such that the interaction among the n submodules is equivalent to the specification of the system. The implementation of the technique is based on an approach proposed by P. Merlin and G.B. Bochmann (1983). The specification of a system and its submodules consists of all possible execution sequences of their individual operations. The ATMS uses finite-state machine concepts to represent the specifications and interactions of the system and its submodules. The specification found by the ATMS for a missing module of a system is the most general one, if one exists. Application of the ATMS in the area of communication protocols is discussed. A manual process to find the specification for a missing module using the Merlin-Bochmann technique is time-consuming and prone to errors. The automated tool presented proves a reliable method for constructing such a module.
Knowledge Bases and Databases: Converging Technologies, Diverging Interests
Authors: Yehudah Freundlich
Venue: Computer (1990)

The convergence of knowledge-based and database technologies in the development of expert databases which store not only values but chunks of knowledge is discussed. The knowledge-based programming perspective is examined, and differences between knowledge bases and databases are identified. It is argued that in spite of converging technologies, the interests of knowledge-base specialists and database specialists differ, and their research directions diverge.
Implicit representation of graphs
Authors: Sampath Kannan, Moni Naor, Steven Rudich
Venue: Proceedings of the twentieth annual ACM symposium on Theory of computing (1988)

How to represent a graph in memory is a fundamental data structuring question. In the usual representations of an n-node graph, the names of the nodes (i.e. integers from 1 to n) betray nothing about the graph itself. Indeed, the names (or labels) on the n nodes are just logn bit place holders to allow data on the edges to code for the structure of the graph. In our scenario, there is no such waste. By assigning &Ogr;(logn) bit labels to the nodes, we completely code for the structure of the graph, so that given the labels of two nodes we can test if they are adjacent in time linear in the size of the labels. Furthermore, given an arbitrary original labeling of the nodes, we can find structure coding labels (as above) that are no more than a small constant factor larger than the original labels. These notions are intimately related to vertex induced universal graphs of polynomial size. For example, we can label planar graphs with structure coding labels of size < 4logn. This implies the existence of a graph with n4 nodes that contains all n-node planar graphs as vertex induced subgraphs (It was not previously known that this class had polynomial sized universal graphs). The theorems on finite graphs extend to a theorem about the constrained labeling of infinite graphs.
MACSYMS's inverse Laplace transform
Authors: M. Clarkson
Venue: ACM SIGSAM Bulletin (1989)

The inverse Laplace transform capability of MACSYMA has been improved and extended. It has been extended to evaluate certain limits, sums, derivatives and integrals of Laplace transforms. It also takes advantage of the inverse Laplace transform convolution theorem, and can deal with a wider range of symbolic parameters.
Hypothetical datalog: complexity and expressibility
Authors: A. J. Bonner
Venue: Lecture notes in computer science on ICDT '88 (1988)

We present an extension of Horn-clause logic which can hypothetically add and delete tuples from a database. Such logics have been discussed in the literature, but their complexities and expressibilities have remained an open question. This paper examines two such logics in the function-free, predicate case. It is shown, in particular, that augmenting Horn-clause logic with hypothetical addition increases its data-complexity from PTIME to PSPACE. When deletions are added as well, complexity increases again, to EXPTIME. To establish expressibility, we augment the logic with negation-by-failure and view it as a query language for relational databases. The logic of hypothetical additions then expresses all database queries which are computable in PSPACE. When deletions are included, the logic expresses all database queries computable in EXPTIME.