ppxscal/embedding_network huggingface dataset:
Introducing memory into the switch elements of multiprocessor interconnection networks
Authors: H. E. Mizrahi, J. L. Baer, E. D. Lazowska, J. Zahorjan
Venue: ACM SIGARCH Computer Architecture News (1989)

As VLSI technology continues to improve, circuit area is gradually being replaced by pin restrictions as the limiting factor in design. Thus, it is reasonable to anticipate that on-chip memory will become increasingly inexpensive since it is a simple, regular structure than can easily take advantage of higher densities. In this paper we examine one way in which this trend can be exploited to improve the performance of multistage interconnection networks (MINs). In particular, we consider the performance benefits of placing significant memory in each MIN switch. This memory is used in two ways: to store (the unique copies of) data items and to maintain directories. The data storage function allows data to be placed nearer processors that reference it relatively frequently, at the cost of increased distance to other processors. The directory function allows data items to migrate in reaction to changes in program locality. We call our MIN architecture the Memory Hierarchy Network (MHN). In a preliminary investigation of the merits of this design [8] we examined the performance of MHNs under the simplifying assumption that an unlimited amount of memory was available in each switch. We found that despite the longer switch processing times of the MHN, system performance is improved over simpler, conventional schemes based on caching. In this paper we refine the earlier model to account for practical storage limitations. We study ways to reduce the amount of directory storage required by keeping only partial information regarding the current location of data items. The price paid for this reduction in memory requirement is more complicated (and in some circumstances slower) protocols. We obtain comparative performance estimates in an environment containing a single global memory module and a tree-structured MIN. Our results indicate that the MHN organization can have substantial performance benefits and so should be of increasing interest as the enabling technology becomes available.
Comprehensible rendering of 3-D shapes
Authors: Takafumi Saito, Tokiichiro Takahashi
Venue: ACM SIGGRAPH Computer Graphics (1990)

We propose a new rendering technique that produces 3-D images with enhanced visual comprehensibility. Shape features can be readily understood if certain geometric properties are enhanced. To achieve this, we develop drawing algorithms for discontinuities, edges, contour lines, and curved hatching. All of them are realized with 2-D image processing operations instead of line tracking processes, so that they can be efficiently combined with conventional surface rendering algorithms.Data about the geometric properties of the surfaces are preserved as Geometric Buffers (G-buffers). Each G-buffer contains one geometric property such as the depth or the normal vector of each pixel. By using G-buffers as intermediate results, artificial enhancement processes are separated from geometric processes (projection and hidden surface removal) and physical processes (shading and texture mapping), and performed as postprocesses. This permits a user to rapidly examine various combinations of enhancement techniques without excessive recomputation, and easily obtain the most comprehensible image.Our method can be widely applied for various purposes. Several of these, edge enhancement, line drawing illustrations, topographical maps, medical imaging, and surface analysis, are presented in this paper.
Solving algebraic systems which arise as necessary integrability conditions for polynomial-nonlinear evolution equations
Authors: V. P. Gerdt, N. V. Khutornoy, A. Y. Zharkov
Venue: Proceedings of the international symposium on Symbolic and algebraic computation (1990)

The investigation of the problem of integrability of polynomial-nonlinear evolution equations, in particular, verifying the existence of the higher symmetries and conservation laws can often be reduced to the problem of finding the exact solution of a complicated system of nonlinear algebraic equations. It is remarkable that these algebraic equations can be not only obtained completely automatically by computer [1] but also often not only completely solved by computer, in spite of their complicated structure and often infinitely many solutions. We demonstrate this fact using the Groebner basis method [2] and obtain all (infinitely many) solutions of the systems of algebraic equations which are equivalent to integrability of three different multiparametric families of NLEEs [1]: the seventh order scalar KdV-like equations, the seventh order MKdV-like equations, and the third order coupled KdV-like systems. All our computations have been carried out by using the computer algebra system REDUCE (version 3.2) on an IBM PC AT-like computer. Because of the fact that the computer algebra system REDUCE 3.2 (in particular on IBM PC, and unlike REDUCE 3.3), has no built-in package for computation of Groebner basis, we have written our own program in Rlisp in order to solve systems of algebraic equations using Buchberger's algorithm [2]. To make the program effecient we have used the distributive form for the internal representation of polynomials together with multivariate factorization. In order to obtain the (infinitely many) solutions, we construct a lexicographic Groebner basis, then we compute, according to [3], the dimension and independent sets of variables for the ideal which is generated by the input system. Thereafter, we consider each set of variables as free parameters and compute a Groebner basis leaving the order of the others unchanged. As a result we obtain a set of Groebner bases with a simple structure, and the solution can be found in an easy way. Our analysis shows that the Groebner basis method allows us to obtain the complete set of exact solutions for systems of nonlinear algebraic equations which are the necessary integrability conditions for NLEEs and therefore to select all integrable evolution equations. It is clear that the solvability of the above systems and of even more complicated ones is closely connected with the property of integrability. In addition to their importance in the theory and application of NLEEs, such systems are very useful for testing different computer algebra algorithms. One of our system is in a list of examples for Groebner basis computations [4].
On the construction of Gröbner bases using syzygies
Authors: H. Michael Möller
Venue: Journal of Symbolic Computation (1988)

Grobner bases are useful for analysing multivariate polynomial ideals. For different coefficient domains R, it is shown how to construct (weak) Grobner bases using bases of modules of syzygies, and under constructibility conditions on R an algorithm for finding the required module bases is given. These methods are described in detail for principal ideal rings R. This leads to strong Grobner bases and in case of fields R the construction is the known Buchberger algorithm.
Module test case generation
Authors: D. Hoffman, C. Brealey
Venue: Proceedings of the ACM SIGSOFT '89 third symposium on Software testing, analysis, and verification (1989)

While considerable attention has been given to techniques for developing complex systems as collections of reliable and reusable modules, little is known about testing these modules. In the literature, the special problems of module testing have been largely ignored and few tools or techniques are available to the practicing tester. Without effective testing methods, the development and maintenance of reliable and reusable modules is difficult indeed. We describe an approach for systematic module regression testing. Test cases are defined formally using a language based on module traces, and a software tool is used to automatically generate test programs that apply the cases. Techniques for test case generation in C and in Prolog are presented and illustrated in detail.
Optimal Chaining in Expression Trees
Authors: D. Bernstein, H. Boral, R. Y. Pinter
Venue: IEEE Transactions on Computers (1988)

Chaining is the ability to pipeline two or more vector instructions on Cray-1 like machines. The authors show how to optimally use this feature to compute (vector) expression trees in the context of automatic code generation. They present a linear time scheduling algorithm for finding an optimal order of evaluation for a machine with a bounded number of registers.
Type inference in a database programming language
Authors: Atsushi Ohori, Peter Buneman
Venue: Proceedings of the 1988 ACM conference on LISP and functional programming (1988)

We extend an ML-like implicit type system to include a number of structures and operations that are common in database programming including sets, labeled records, joins and projections. We then show that the type inference problem of the system is decidable by extending the notion of principal type schemes to include conditions on substitutions. Combined with Milner's polymorphic let constructor, our language also supports type inheritance.
On Criteria for Module Interfaces
Authors: Daniel Hoffman
Venue: IEEE Transactions on Software Engineering (1990)

While the benefits of modular software development are widely acknowledged, there is little agreement as to what constitutes a good module interface. Computational complexity techniques allow evaluation of algorithm time and space costs but offer no guidance in the design of the interface to an implementation. Yet, interface design decisions often have a critical effect on the development and maintenance costs of large software systems. Criteria that have led to simple, elegant interfaces are presented in detail. These criteria have been developed and refined through repeated practical application. The use of the criteria is illustrated with concrete examples.
Abstractions in semantic networks: axiom schemata for generalization, aggregation and grouping
Authors: Ulrich Schiel
Venue: Issue 107 (January 1989) (1989)

A successful complex expert system, Kardio's model of the human heart is designed for the diagnosis of cardiac arrhythmias. Kardio is highly skilled in the reading of ECG recordings, and can be used as a diagnostic tool in ECG interpretation. In this groundbreaking account, the authors show how the model was compiled, by means of qualitative simulation and machine learning tools, into various representations that are suited for particular expert tasks. They investigate a hierarchical organization of a qualitative model and outline an experiment whereby the construction of a deep model is automated by machine learning techniques. The book contains a complete model of the electrical system of the heart.
The x-kernel: A Platform for Accessing Internet Resources
Authors: Larry Peterson, N. Hutchinson, Sean O'Malley, Herman Rao
Venue: Computer (1990)

x-kernel is an experimental operating system for personal workstations that allows uniform access to resources throughout a nationwide internet: an interconnection of networks similar to the TCP/IP internet. This network is also called the National Research and Education Network (NREN). The x-kernel supports a library of protocols, and it accesses different resources with different protocol combinations. In addition, two user-level systems that give users an integrated and uniform interface to resources have been built on top of the x-kernel. These two systems-a file system and a command interpreter-hide differences among the underlying protocols.
Fast Parallel Algorithms for Binary Multiplication and their Implementation on Systolic Architectures
Authors: B. P. Sinha, P. K. Srimani
Venue: IEEE Transactions on Computers (1989)

Two algorithms for parallel multiplication of two n-bit binary numbers are presented. Both use column compression to increase the speed of execution. They require almost regular interconnection between only two types of cells and hence are very suitable for VLSI implementation. Both of them can also be easily modified to handle two's complement numbers with constant differences in time.
Computer algebra applied to itself
Authors: J. H. Davenport
Venue: Journal of Symbolic Computation (1988)

This paper explains how computer algebra (Reduce) was used to analyse the expressions resulting from the complexity analysis of a family of algorithms for the isolation of real roots of polynomials. The expressions depend on sufficiently many parameters, and are sufficiently complex, that manual analysis would have been almost impossible. In addition, by analysing constant factors as well as the 0 form of the expressions, we obtain more information about the relative costs of algorithms with the same 0 complexity.
The maximum concurrent flow problem
Authors: Farhad Shahrokhi, D. W. Matula
Venue: Journal of the ACM (JACM) (1990)

The maximum concurrent flow problem (MCFP) is a multicommodity flow problem in which every pair of entities can send and receive flow concurrently. The ratio of the flow supplied between a pair of entities to the predefined demand for that pair is called throughput and must be the same for all pairs of entities for a concurrent flow. The MCFP objective is to maximize the throughput, subject to the capacity constraints. We develop a fully polynomial-time approximation scheme for the MCFP for the case of arbitrary demands and uniform capacity. Computational results are presented. It is shown that the problem of associating costs (distances) to the edges so as to maximize the minimum-cost of routing the concurrent flow is the dual of the MCFP. A path-cut type duality theorem to expose the combinatorial structure of the MCFP is also derived. Our duality theorems are proved constructively for arbitrary demands and uniform capacity using the algorithm. Applications include packet-switched networks [1, 4, 8], and cluster analysis [16].
An improved mixture rule for pattern matching
Authors: J. Ophel
Venue: ACM SIGPLAN Notices (1989)

An improved mixture rule for compiling the pattern matching mechanism used in function definitions for ML, Miranda and Hope is presented. The new rule produces better code for patterns with mixed constructors and variables in multiple columns.
Inductive pebble games and the expressive power of datalog
Authors: V. S. Lakshmanan, A. O. Mendelzon
Venue: Proceedings of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1989)

As an alternative to logic-based query languages for recursive queries, we are investigating a graphical query language called G+, which allows, among other things, easy formulation of certain queries involving simple paths in directed graphs. This led us to study whether such queries are expressible in DATALOG, the language of function-free Horn clauses. Since some G+ queries are NP-hard, and all DATALOG queries are polynomial time computable, the answer appears to be negative. However, it would be interesting to have proof techniques and tools for settling such questions with certainty. The objective of this paper is the development of one such tool, inductive pebble games, based on a normal form for DATALOG programs derived here, and its relationship to Alternating Turing Machine computations. As an application, we sketch a proof that the query &ldquo;find all pairs of nodes connected by a directed simple path of even length&rdquo; cannot be expressed in DATALOG.
3-D Motion Estimation Using a Sequence of Noisy Stereo Images: Models, Estimation, and Uniqueness Results
Authors: G.-S. J. Young, R. Chellappa
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

A kinematic model-based approach for the estimation of 3-D motion parameters from a sequence of noisy stereo images is discussed. The approach is based on representing the constant acceleration translational motion and constant precession rotational motion in the form of a bilinear state-space model using standard rectilinear states for translation and quaternions for rotation. Closed-form solutions of the state transition equations are obtained to propagate the quaternions. The measurements are noisy perturbations of 3-D feature points represented in an inertial coordinate system. It is assumed that the 3-D feature points are extracted from the stereo images and matched over the frames. Owing to the nonlinearity in the state model, nonlinear filters are designed for the estimation of motion parameters. Simulation results are included. The Cramer-Rao performance bounds for motion parameter estimates are computed. A constructive proof for the uniqueness of motion parameters is given. It is shown that with uniform sampling in time, three noncollinear feature points in five consecutive binocular image pairs contain all the spatial and temporal information. Both nondegenerate and degenerate motions are analyzed. A deterministic algorithm to recover motion parameters from a stereo image sequence is summarized from the constructive proof.
SYGRAF: Implementing Logic Programs in a Database Style
Authors: Micheal Kifer, Eliezer L. Lozinskii
Venue: IEEE Transactions on Software Engineering (1988)

It is shown how Horn logic programs can be implemented using database techniques, namely, mostly bottom-up in combination with certain top-down elements (as opposed to the top-down implementations of logic programs prevailing so far). The proposed method is sound and complete. It easily lends itself to a parallel implementation and is free of nonlogical features like backtracking. As an extension to the common approach to deductive databases, function symbols are allowed to appear in programs, and it is shown that much of database query optimization can be applied to optimize logic programs. An important advantage of present approach is its ability to evaluate successfully many programs that terminate under neither pure top-down nor bottom-up evaluation strategies.
The essence of ML
Authors: J. C. Mitchell, R. Harper
Venue: Proceedings of the 15th ACM SIGPLAN-SIGACT symposium on Principles of programming languages (1988)

Standard ML is a useful programming language with polymorphic expressions and a flexible module facility. One notable feature of the expression language is an algorithm which allows type information to be omitted. We study the implicitly-typed expression language by giving a &ldquo;syntactically isomorphic&rdquo; explicitly-typed, polymorphic function calculus. Unlike the Girard-Reynolds polymorphic calculus, for example, the types of our ML calculus may be built-up by induction on type levels (universes). For this reason, the pure ML calculus has straightforward set-theoretic, recursion-theoretic and domain-theoretic semantics, and operational properties such as the termination of all recursion-free programs may be proved relatively simply. The signatures, structures, and functors of the module language are easily incorporated into the typed ML calculus, providing a unified framework for studying the major features of the language (including the novel &ldquo;sharing constraints&rdquo; on functor parameters). We show that, in a precise sense, the language becomes inconsistent if restrictions imposed by type levels are relaxed. More specifically, we prove that the important programming features of ML cannot be added to any impredicative language, such as the Girard-Reynolds calculus, without implicitly assuming a type of all types.
A Taxonomy of Reconfiguration Techniques for Fault-Tolerant Processor Arrays
Authors: Mengly Chean, Jose A. B. Fortes
Venue: Computer (1990)

Focuses on the characterization and classification of reconfiguration techniques. The techniques are differentiated according to the type of redundancy (time or hardware), allocation of redundancy (local or global), replacement unit, (processor or a set of processors), switching domain (global or local), and switching implementation (switching element, bus, or network). Typical techniques from four major classes-set switching, processor switching, local redundancy, and time redundancy-are reviewed. The proposed taxonomy can be used as a guide for future research in design and analysis of reconfiguration schemes.
An Interobject Distance Measure Based on Medial Axes Retrieved from Discrete Distance Maps
Authors: P.-O. Forsgren, P. Seideman
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

A method that measures the distance between extended objects of nonregular shape is presented. The distance measure is an average of a set of minimal point-to-point distances between the borders of the objects. The set of points is collected with a well-defined criterion based on processing of distance values on a connected medial axis formed between the objects.
The need for closure in large distributed systems
Authors: B. C. Neuman
Venue: ACM SIGOPS Operating Systems Review (1989)

As the size of a distributed system grows it becomes increasingly difficult for users to find their way around. One solution for this problem is user centered naming. A problem with user centered naming is that it has the potential to cause confusion and to make sharing difficult. This problem can be avoided if the system supports closure. Although the same name may refer to different objects at different times, the context in which the name is to be evaluated is always known.
Moderating effects of age, education, and tenure on the job satisfaction-job performance relationship
Authors: C. K. Woodruff
Venue: Proceedings of the ACM SIGCPR conference on Management of information systems personnel (1988)

An exploratory investigation was conducted to clarify the role of age, education level attained, and tenure as potential moderators of the relationship of job satisfaction and job performance for information systems personnel. Participants in an empirical study included 202 individuals from twelve computer centers. No support was found for age, education level attained, and tenure as moderators. This lack of support extended beyond a summated measure of total job performance to each of the component performance measures: quantity of work, quality of work, job knowledge, job judgment, job initiative, adaptability, cooperation, and innovativeness. A small statistically significant relationship was found for these variables on job knowledge and job judgment.
Real-time interval logic for reasoning about executions of real-time programs
Authors: R. Razouk, M. Gorlick
Venue: Proceedings of the ACM SIGSOFT '89 third symposium on Software testing, analysis, and verification (1989)

Research on the testing and debugging of distributed real-time programs now focuses on more formal approaches to specification and testing. Temporal logic is a natural candidate for this since it can specify properties of event and state sequences. However, the absence of any concept of real-time limits the application of temporal logic to non real-time behavior. This paper presents an extension of the interval logic of Schwartz et al. [SMSVP83], by increasing the expressive power of the logic (with respect to real time) while retaining its intuitive appeal and understandability. The extensions are added in a &ldquo;layer&rdquo; that can be stripped away if formal verification is the goal, or retained if timing behavior must be tested. The extensions include: the ability to deal with real time (as in [JM86b, JM86a, OW87, NA88]); more powerful interval specification mechanisms; a limited form of quantification; and the direct expression of event predicates (as in [LeD86]). Since our work is intended to yield practical tools for software testers, we emphasize the ease of expressing the complex timing properties of real-time software (e.g. periodic behavior, performance constraints), and we demonstrate the use of the interval logic on some real-time examples that represent a test of the expressiveness and understandability of the notation.