ppxscal/embedding_network huggingface dataset:
Heuristic algorithms for distributed query processing
Authors: P. Bodorik, J. S. Riordon
Venue: Proceedings of the first international symposium on Databases in parallel and distributed systems (2000)

This paper examines heuristic algorithms for processing distributed queries using generalized joins. As this optimization problem is NP-hard heuristic algorithms are deemed to be justified. A heuristic algorithm to form/formulate strategies to process queries is presented. It has a special property in that its overhead can be &ldquo;controlled&rdquo;: The higher its overhead the better the strategies it produces. Modeling on a test-bed of queries is used to demonstrate that there is a trade-off between the strategy's execution and formulation delays. The modeling results also support the notion that simple greedy heuristic algorithms such as are proposed by many researchers are sufficient in that they are likely to lead to near-optimal strategies and that increasing the overhead in forming strategies is only marginally beneficial. Both the strategy formulation and execution delays are examined in relation to the number of operations specified by the strategy and the total size of partial results.
A programming environment supporting reuse of object-oriented software
Authors: H. Tarumi, K. Agusa, Y. Ohno
Venue: Proceedings of the 10th international conference on Software engineering (1988)

We have developed a programming environment for object-oriented programming. This environment supports reuse of classes, especially retrieval of them with an expert system. The user can find classes and methods by describing the features of objects and operations according to an object model proposed by us. The target programming language is MOMO, which is developed by us to implement the object model. This paper mainly focuses on the retrieval part of the environment.
Proof of a conjecture of R. Kannan
Authors: J.-C. Birget
Venue: Proceedings of the twenty-first annual ACM symposium on Theory of computing (1989)

R. Kannan conjectured that every non-deterministic two-way finite automaton can be positionally simulated by a deterministic two-way finite automaton. The conjecture is proved here by reduction to a similar problem about finite semigroups. The method and the result are then generalized to alternating two-way finite automata.
Morphological Shape Decomposition
Authors: I. Pitas, A. N. Venetsanopoulos
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1990)

A technique for decomposing a binary shape into a union of simple binary shapes is presented. The decomposition is shown to be unique and invariant to translation, rotation, and scaling. The techniques used in the decomposition are based on mathematical morphology. The shape description produced can be used in object recognition and in binary image coding.
Two remarks on Tau-splines
Authors: Dieter Lasser
Venue: ACM Transactions on Graphics (TOG) (1990)

We present a B&eacute;zier representation of &tgr;-splines, curvature and torsion-continuous quintics, which were introduced in CAGD by Hagen in 1985 [32]. Explicit formulas are given for the conversion from B&eacute;zier representation to &tgr;-spline representation, and vice versa. Thus, by embedding the B&eacute;zier representation in a &Bgr;-spline representation of curvature and torsion-continuous quintic spline curves, given in [20], a &Bgr;-spline-B&eacute;zier representation of &tgr;-splines results. Second, positivity conditions for the design parameters of the B&eacute;zier representation and certain ranges of tension values are derived, which ensure properties like the convex hull and the variation-diminishing property of the &Bgr;-spline-B&eacute;zier representation.
Directed dialogue protocols: verbal data for user interface design
Authors: S. T. Knox, W. A. Bailey, E. F. Lynch
Venue: ACM SIGCHI Bulletin (1989)

The development of an interface design tool called &ldquo;directed dialogue protocols&rdquo; is discussed. The tool is based upon Kato's (1986) method of verbal data collection, &ldquo;question-asking protocols.&rdquo; Three extensions to the question-asking method are detailed: 1) an experimental procedure of atomic tasks which facilitate the quantization of verbal data; 2) interventions by the experimenter that probe the subject's expectations and prompt verbalizations; and 3) a technique for answering subject queries called sequential disclosure. Also discussed are applications of the directed dialogue that have identified design choices which build learnability and usability into a product's user-interface.
The fuzzy barrier: a mechanism for high speed synchronization of processors
Authors: Rajiv Gupta
Venue: ACM SIGARCH Computer Architecture News (1989)

Parallel programs are commonly written using barriers to synchronize parallel processes. Upon reaching a barrier, a processor must stall until all participating processors reach the barrier. A software implementation of the barrier mechanism using shared variables has two major drawbacks. Firstly, the execution of the barrier may be slow as it may not only require execution of several instructions and but also result in hot-spot accesses. Secondly, processors that are stalled waiting for other processors to reach the barrier are essentially idling and cannot do any useful work. In this paper, the notion of the fuzzy barrier is presented, that avoids the above drawbacks. The first problem is avoided by implementing the mechanism in hardware. The second problem is solved by extending the barrier concept to include a region of statements that can be executed by a processor while it awaits synchronization. The barrier regions are constructed by a compiler and consist of several instructions such that a processor is ready to synchronize upon reaching the first instruction in this region and must synchronize before exiting the region. When synchronization does occur, the processors could be executing at any point in their respective barrier regions. The larger the barrier region, the more likely it is that none of the processors will have to stall. Preliminary investigations show that barrier regions can be large and the use of program transformations can significantly increase their size. Examples of situations where such a mechanism can result in improved performance are presented. Results based on a software implementation of the fuzzy barrier on the Encore multiprocessor indicate that the synchronization overhead can be greatly reduced using the mechanism.
A grammar-based approach to automatic generation of user-interface dialogues
Authors: M. L. Scott, S.-K. Yap
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1988)

An effective user interface requires a dialogue layer that can handle multiple threads of interaction simultaneously. We propose a notation for specifying dialogues based on context-free attributed grammars with two extensions: fork operators for specifying sub-dialogues and context attributes for dispatching tokens. The notation is useful both as a means of communicating the behavior of the dialogue layer to designers and as input to a dialogue compiler that generates program code. In this paper we explain the motivation for our work and provide practical examples of the use of fork and context. In addition, we outline algorithms for parsing and for generating parser tables.
On the parallel decomposability of geometric problems
Authors: M. J. Atallah, J. J. Tsay
Venue: Proceedings of the fifth annual symposium on Computational geometry (1989)

There is a large and growing body of literature concerning the solution of geometric problems on mesh-connected arrays of processors [5,9,14,17]. Most of these algorithms are optimal (i.e., run in time &Ogr;(n1/d) on a d-dimensional n-processor array), and they all assume that the parallel machine is trying to solve a problem of size n on an n-processor array. What happens when we have parallel machine for efficiently solving a problem of size p, and we are interested in using it to solve a problem of size n < p? The answer to that question has to do with a fundamental, and yet (at least so far) little-studied property of geometric problems: their parallel-decomposability. More specifically, given that a problem of size p can be solved on a parallel machine P faster by a factor of (say) s(p) than on a RAM alone, then that problem is fully parallel-decomposable for P if a RAM to which the parallel machine P is attached can solve arbitrarily large problems with a speedup of also s(p) when compared to a RAM alone. The issue has been settled for the sorting problem when P is a linear systolic array [1,2,3,11]. Here we show that many geometric problems are fully parallel-decomposable for (multidimensional) mesh-connected arrays of processors.
A comparison of selected conceptual frameworks for simulation modeling
Authors: E. J. Derrick, O. Balci, R. E. Nance
Venue: Proceedings of the 21st conference on Winter simulation (1989)

The purpose of this paper is to compare thirteen Conceptual Frameworks (CFs) selected from among several categories of applicability to discrete-event simulation modeling. Each CF is briefly reviewed to provide the background information required for the comparison. Based on the insights gained in applying the CFs to the modeling of a complex traffic intersection system, the CFs are compared relative to their distinct characteristics and capabilities. Comparative comments are grouped according to the design guidance and implementation guidance features of the CFs. Conclusions highlight the inadequacies of the CFs and the importance of research in CF development.
Some sad remarks about string handling in C
Authors: P. W. Abrahams
Venue: ACM SIGPLAN Notices (1988)

Many people have criticized the C programming language for its failure to enforce discipline in programming. They cite the lack of typechecking and the locutions that expose and indeed emphasize the underlying machine model. C is less often criticized for lack of efficiency. Yet in a critical part of the language -- string handling -- the efficiency of C falls short of the mark.String handling is a major application of C. In the original C book by Kernighan and Ritchie, nearly every example has something to do with strings. In systems programming, another major application, string handling is a large part of the task. If a skillful C programmer cannot easily write programs that manipulate strings efficiently, then the language has failed to meet one of its central goals.There are two problems with strings in C. The first is the use of a representation for strings in which a terminating null character indicates the length of the string. The second is the lack of built-in operations on strings analogous to the ones provided for arithmetic data.
Hypercube data analysis in astronomy: optical interferometry and millisecond pulsar searches
Authors: P. Gorham, T. Prince, S. Anderson
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

Astronomical data sets are beginning to live up to their name, in both their sizes and the complexity of the analysis required. Here we discuss two astronomical data analysis problems which we have begun to implement on a hypercube concurrent processor environment: The intensive image processing required in an optical interferometry project, and the large scale power spectral analysis required by a search for millisecond-period radio pulsars. In both cases the analysis proceeds largely in the Fourier domain, and we find that the problems are readily adapted to a concurrent environment. In the following report, we outline briefly the astronomical background for each problem, then discuss the general computational requirements, and finally present possible hypercube algorithms and results achieved to date.
A Theory for Multiresolution Signal Decomposition: The Wavelet Representation
Authors: S. G. Mallat
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

Multiresolution representations are effective for analyzing the information content of images. The properties of the operator which approximates a signal at a given resolution were studied. It is shown that the difference of information between the approximation of a signal at the resolutions 2/sup j+1/ and 2/sup j/ (where j is an integer) can be extracted by decomposing this signal on a wavelet orthonormal basis of L/sup 2/(R/sup n/), the vector space of measurable, square-integrable n-dimensional functions. In L/sup 2/(R), a wavelet orthonormal basis is a family of functions which is built by dilating and translating a unique function psi (x). This decomposition defines an orthogonal multiresolution representation called a wavelet representation. It is computed with a pyramidal algorithm based on convolutions with quadrature mirror filters. Wavelet representation lies between the spatial and Fourier domains. For images, the wavelet representation differentiates several spatial orientations. The application of this representation to data compression in image coding, texture discrimination and fractal analysis is discussed.
Tool integration in Arcadia
Authors: R. N. Taylor
Venue: Proceedings of the conference on TRI-Ada '88 (1989)

The objective of the Arcadia research project is to produce a family of evolvable software development and maintenance project support environments based on adaptive, self-analytic, proactive architectural components and formal definition, analysis, and evaluation of the software process and products. Research in &ldquo;techniques and tools&rdquo; is focussed on analysis capabilities for sequential and concurrent software systems and on language processing. The distinguishing characteristic of the architecture research is that solutions in the component technologies are being developed in a cooperative, synergistic fashion, for it is the interactions between the components that often raise the most challenging questions.
Simultaneous Optimal Segmentation and Model Estimation of Nonstationary Noisy Images
Authors: J. Goutsias, J. M. Mendel
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1989)

The authors present the class of semi-Markov random fields and deal, in particular, with the subclass of discrete-valued, nonsymmetric half-plane, unilateral Markov random fields. A hierarchical nonstationary-mean nonstationary-variance (NMNV) image model is proposed for the modeling of nonstationary and noisy images. This model seems to be advantageous as compared to a regular NMNV model because it statistically incorporates the correlation between pixels around the boundary of two adjacent regions. The hierarchical NMNV model leads to the development of an optimal algorithm that allows the simultaneous segmentation and model estimation of measured images. Although no theoretical result is available for the consistency of the estimated model parameters, the method seems to work sufficiently well for the examples considered.
Array expansion
Authors: P. Feautrier
Venue: Proceedings of the 2nd international conference on Supercomputing (1988)

A common problem in restructuring programs for vector or parallel execution is the suppression of false dependencies which originate in the reuse of the same memory cell for unrelated values. The method is simple and well understood in the case of scalars. This paper gives the general solution for the case of arrays. The expansion is done in two steps: first, modify all definitions of the offending array in order to obtain the single assignment property. Then, reconstruct the original data flow by adapting all uses of the array. This is done with the help of a new algorithm for solving parametric integer programs. The technique is quite general and may be used for other purposes, including program checking, collecting array predicates, etc&hellip;
Optimal size integer division circuits
Authors: J. H. Reif
Venue: Proceedings of the twenty-first annual ACM symposium on Theory of computing (1989)

Division is a fundamental problem for arithmetic and algebraic computation. This paper describes Boolean circuits (of bounded fan-in) for integer division (finding reciprocals) that have size &Ogr;(M(n)) and depth &Ogr;(lognlog logn), where M(n) is the size complexity of &Ogr;(logn) depth integer multiplication circuits. Currently, M(n) is known to be &Ogr;(nlogn log,n), but any improvement in this bound that preserves circuit depth will be reflected by a similar improvement in the size complexity of our division algorithm. Previously, no one has been able to derive a division circuit with size &Ogr;(n logc n) for any c, and simultaneous depth less than &OHgr;(log2 n). Our circuits are logspace uniform; that is, they can be constructed by a deterministic Turing machine in space &Ogr;(log n). Our results match the best known depth bounds for logspace uniform circuits, and are optimal in size. The general method of high order iterative formulas is of independent interest as a way of efficiently using parallel processors to solve algebraic problems. In particular, our algorithm implies that any rational function can be evaluated in these complexity bounds. As an introduction to high order iterative methods we also present a circuit for finding polynomial reciprocals (where the coefficients come from an arbitrary ring, and ring operations are unit cost in the circuit) in size &Ogr;(PM (n)) and depth &Ogr;(log n log log n), where PM(n) is the size complexity of optimal depth polynomial multiplication.
Control flow analysis in scheme
Authors: O. Shivers
Venue: Proceedings of the ACM SIGPLAN 1988 conference on Programming Language design and Implementation (1988)

Traditional flow analysis techniques, such as the ones typically employed by optimizing Fortran compilers, do not work for Scheme-like languages. This paper presents a flow analysis technique &mdash; control flow analysis &mdash; which is applicable to Scheme-like languages. As a demonstration application, the information gathered by control flow analysis is used to perform a traditional flow analysis problem, induction variable elimination. Extensions and limitations are discussed. The techniques presented in this paper are backed up by working code. They are applicable not only to Scheme, but also to related languages, such as Common Lisp and ML.
An algorithm for the construction of matrix representationsfor finitely presented non-commutative algebras
Authors: Gilles Labonté
Venue: Journal of Symbolic Computation (1990)

Let a finite presentation be given for an associative, in general non-commutative algebra E, with identity, over a field. We study an algorithm for the construction, from this presentation, of linear, i.e. matrix, representations of this algebra. A set of vector constraints which is given as part of the initial data, determines which particular representation of E is produced. This construction problem for the algebra is solved through a reduction of it to the muchsimpler problem of constructing a Grobner basis for a left module. The price paid for this simplification is that the latter is then infinitely presented. Convergence of the algorithm is proven for all cases where the representation to be found is finite dimensional; which is always the case, for example, when E is finite. Examples are provided, some of which illustrate the close relationship that exists between this method and the Todd-Coxeter coset-enumeration method for group theory.
Behavioral modeling of transmission gates in VHDL
Authors: S. S. Leung
Venue: Proceedings of the 26th ACM/IEEE Design Automation Conference (1989)

This paper presents a technique for describing the behavior of transmission gates (TGs) in VHDL. The concept of virtual signal is introduced into the TG's data structure to represent the nature of the connection. The model's semantics are coded in three parts: the state transition, the steady states, and the connecting protocol. Simulation results indicate that the model is correct and robust.
Staying afloat&mdash;a collective enterprise
Authors: J. B. Slater
Venue: ACM SIGUCCS Newsletter (1989)

Higher Education in the UK can be characterised by a division into Polytechnics, (until recently funded essentially by Local Education Authorities) and Universities (private organisations). This description of the division, often called the binary divide, hides from a outside observer both the fact that both sides of the divide are essentially government funded and the fact that the divide is essentially a rift.
Collective steropsis on the hypercube
Authors: R. Battiti
Venue: Proceedings of the third conference on Hypercube concurrent computers and applications - Volume 2 (1989)

A cooperative algorithm for extracting disparity information from stereo image pairs has been implemented on the NCUBE hypercube computer. Software is written in C-langauge, using communication routines of the &ldquo;Crystalline Operating System&rdquo; CrOSIII designed at Caltech within the Caltech Concurrent Computation Program. Some tests have been done using Julesz's random-dot stereograms. Although the software is reasonably versatile and can be easily adapted for different flavors of stereo algorithms, the method used is that presented by Marr and Poggio [REF.1]. As a preliminary stage for the stereo matching problem, a &ldquo;filtering&rdquo; program to extract physically meaningful primitives from images of a given scene has been written and tested on various types of images.
Reliable Broadcast in Hypercube Multicomputers
Authors: P. Ramanathan, K. G. Shin
Venue: IEEE Transactions on Computers (1988)

A simple algorithm for broadcasting in a hypercube multicomputer containing faulty nodes/links is proposed. The algorithm delivers multiple copies of the broadcast message through disjoint paths to all the modes in the system. Its salient feature is that the delivery of the multiple copies is transparent to the processes receiving the message and does not require the processes to know the identity of the faulty processors. The processes on nonfaulty nodes that receive the message identify the original message from the multiple copies using some scheme appropriate for the fault model used. The algorithm completes in n+1 steps if each node can simultaneously use all of its outgoing links. If each node cannot use more than one outgoing link at a time, then the algorithm requires 2n steps.
Efficient emulations of interconnection networks
Authors: Arnold Rosenberg
Venue: ACM SIGARCH Computer Architecture News (1989)

We describe a graph-theoretic framework for comparing the communication powers of competing interconection networks. The framework attempts to determine how efficiently each of the networks can emulate the other on general computations (including pipelining). After briefly surveying a number of studies in the literature that use the described framework, we present a case study that illustrates the strengths of the framework. The study comprises three surprisingly efficient emulations by shuffle-oriented networks (such as the shuffle-exchange and deBruijn networks) of butterfly-oriented networks (such as the butterfly and cube-connected cycles networks). Each emulation is efficient in its own way: The first emulates a butterfly network on a like-sized deBruijn network, incurring a slowdown that is exponentially faster than previous emulations. (We concentrate on the butterfly and deBruijn networks in order to minimize constant factors.) The second emulates a large butterfly network on a small deBruijnnetwork, in a way that is work-preserving, in that the slowdown times; processor-count product is preserved. The third emulates a small butterfly network on a large deBruijn network, incurring optimally small slowdown.