ppxscal/embedding_network huggingface dataset:
Sometimes ''Some'' is as Good as ''All'' (Preliminary Version)
Authors: Doron Peled
Venue:  (1992)

The representation of partial order semantics as an equivalence relation on interleaving sequences extends the expressive power of interleaving semantics. A specification formalism called existential specification is introduced: a formula is interpreted over equivalence classes of sequences by asserting that some (at least one but not necessarily all) sequences from each equivalence class satisfy a given property. It differs from the more common universal specification, which is interpreted over all sequences in all classes. Its advantage over other formalisms that deal with partial order executions lies in its simplicity: any syntax that is defined over interleaving sequences, e.g., linear temporal logic, can be adopted. It is shown how under an appropriate semantical construction, an exact existential specification of a program (i.e., each property of the program expressed using the formalism is a consequence of this specification) can be given. Moreover, under such a construction, no information about the program is lost by choosing exact existential specification rather than exact universal specification; it is possible to generalise by means of a proof rule an exact existential specification into an exact universal specification. Deducing an exact existential specification from an exact universal specification is also possible. This provides a relatively complete proof system for existential specification. Applications of these results to compositionality are discussed.
Tiny Families of Functions with Random Properties: A Quality-Size Trade-off for Hashing
Authors: O. Goldreich, A. Wegderson
Venue:  (1994)

We present three explicit constructions of hash functions, which exhibit a trade-off between the size of the family (and hence the number of random bits needed to generate a member of the family), and the quality (or error parameter) of the pseudo-random property it achieves. Unlike previous constructions, most notably universal hashing, the size of our families is essentially independent of the size of the domain on which the functions operate. The first construction is for the mixing property-mapping a proportional part of any subset of the domain to any other subset. The other two are for the extraction property-mapping any subset of the domain almost uniformly into a range smaller than it. The second and third constructions handle (respectively) the extreme situations when the range is very large or very small. We provide lower bounds showing our constructions are nearly optimal, and mention some applications of the new constructions.
Heterogeneous Process Migration: The Tui System
Authors: Peter Smith, Norman C. Hutchinson
Venue:  (1996)

Heterogeneous Process Migration is a technique whereby an active process is moved from one machine to another. It must then continue normal execution and communication. The source and destination processors can have a different architecture, that is, different instruction sets and data formats. Because of this heterogeneity, the entire process memory image must be translated during the migration. "Tui" is a prototype migration system that is able to translate the memory image of a program (written in ANSI-C) between four common architectures (m68000, SPARC, i486 and PowerPC). This requires detailed knowledge of all data types and variables used with the program. This is not always possible in non type-safe (but popular) languages such as C, Pascal and Fortran. The important features of the Tui algorithm are discussed in great detail. This includes the method by which a program''s entire set of data values can be located, and eventually reconstructed on the target processor. Initial performance figures demonstrating the viability of using Tui for real migration applications are given.
FAST-INV: A Fast Algorithm for building large inverted files
Authors: Edward A. Fox, Whay C. Lee
Venue:  (1991)

Inverted files are widely used in building bibliographic and other types of retrieval systems. In order to investigate the utility of advance information retrieval methods for improving access to large online library catalogs, it was necessary to extend the SMART system in a variety of ways. One particular problem was to develop a fast method to produce an inverted file from hundreds of thousands of (partial) MARC records. The FAST-INV software was developed in 1986, taking advantage of the large primary memories available on modern computers and the order inherent in the input data. Using the new algorithm, processing in primary memory for N basic data elements has time complexity O(N), and processing of files that will not fit in primary memory can be accomplished in a fixed number of passes. Performance studies show this approach to be (at least) an order of magnitude faster than commonly used techniques. It is hoped that these findings will be of interest to database providers and will help them reduce costs relating to the building of inverted files, as we have been doing for the last five years.
DETERMINING POSSIBLE EVENT ORDERS BY ANALYZING SEQUENTIAL TRACES
Authors: D. P. Helmbold, C. E. McDowell, Wang,  J-Z.
Venue:  (1991)

One of the fundamental problems encountered when debugging a parallel program is determining the possible orders in which events could have occurred. Various problems, such as data races and intermittent deadlock, arise when there is insufficient synchronization between the tasks in a parallel program. A sequential trace of an execution can be misleading, as it implies additional event orderings, distorting the concurrent nature of the computation. This paper describes algorithms which generate those event orderings which can be relied on by the programmer from the trace of an execution. By its very nature, the information in an execution trace pertains only to that execution of the program, and may not generalize to other executions. We tackle this difficulty in a systematic way: defining an "inferred program" based on the trace and original program, analyze this inferred program, and prove a relationship between the inferred program and the original. The results of our algorithms can be used by other automated tools such as a data race detector or constraint checker. The basic algorithms described here have been implemented in a working trace analyzer for IBM Parallel Fortran. The trace analyzer graphically presents the discovered event orderings and reports various potential data races in the subject program.
SIMULATION OF ELASTIC MEMBRANES AND SOFT TISSUE WITH TRIANGULATED SPRING MESHES
Authors: Allen VanGelder, Jane Wilhelms
Venue:  (1997)

Spring meshes have been used to model elastic material by numerous researchers, with skin, textiles, and soft tissue being typical applications. However, given a specified set of elastic material properties, the question of whether a particular spring mesh accurately simulates those properties, has been largely ignored in the literature. Indeed, from the finite element literature, it would appear that, even for a uniform, isotropic elastic membrane, such a simulation is generally impossible. In two dimensions, given a discretization of a membrane as a triangle mesh, the standard finite element method analyzes each triangle approximately as a membrane with specified elastic properties, computing stresses and strains. An alternative is to regard each edge as a spring, assuming the springs are connected by "pin-joints" at the vertices of the discretization. This alternative, called a "spring mesh", is computationally more attractive. Previous reports on the technique are silent on the subject of assigning stiffness to the various springs. This paper shows that assigning the same stiffness to all springs fails to simulate a uniform elastic membrane, for equilibrium calculations. A formula for spring stiffness that provides an accurate simulation is then derived.
Reasoning about TLA Actions
Authors: Carlos Pacheco
Venue:  (2001)

We use the ACL2 theorem prover to verify invariants of a distributed algorithm specified in TLA (Temporal Logic of Actions). The algorithm, Disk Synod, achieves consensus among a set of processors communicating through disks. We discuss the translation of TLA specifications into a finite set theory framework in ACL2, as well as the proof of two invariant properties of Disk Synod.
Some Connections Between the Minimal Polynomial and the Automorphism
Authors: A. Mowshowitz, G. Criscuolo, R. Tortora, Chung Kwok
Venue:  (1977)

The relationship between the spectrum and the automorphism group of a graph is probed with the aid of the theory of finite group representations. Three related topics are explored: l) graphs with non-derogatory adjacency matrix, 2) point-symmetric graphs, and 3) an algorithm for constructing the automorphism group of a prime, point-symmetric graph. First, we give an upper bound on the order of the automorphism group of a graph with non-derogatory adjacency matrix; and show, in a special case, that the degree of each irreducible factor of the minimal polynomial has a natural interpretation in terms of the automorphism group. Second, we prove that the degree of the minimal polynomial of a point-symmetric graph is bounded above by the number of orbits of the stabilizer of any given element. For point-symmetric graphs with a prime number of points, we exhibit a formula linking the degree of the minimal polynomial with the order of the group. Finally, we give a simple algorithm for constructing the automorphism group of a point-symmetric graph with a prime number of points.
Towards extended price models in XML standards for electronic product catalogs
Authors: Oliver Kelkar, Joerg Leukel, Volker Schmitz
Venue: Enterprise information systems IV (2003)

The extending interorganizational electronic business (business-to-business) means system to system communication between business partners without any manual interaction. This has led to the development of new standards for the exchange of electronic product catalogs (e-catalogs), which are the starting point for business-to-business trading. E-catalogs contain various information about products, essential are price information. Prices are used for buying decisions and following order transactions. While simple price models are often sufficient for the description of indirect goods (e.g. office supplies), other goods and lines of business make higher demands. In this paper we examine what price information is contained in commercial XML standards for the exchange of product catalog data. For that purpose we bring the different implicit price models of the examined catalog standards together and provide a generalized model.
Generation of all-quadrilateral meshes using a triangular mesh generator
Authors: D. Rypl, Z. Bittnar
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

This paper deals with discretization of 3D surfaces into all-quadrilateral meshes. The focus is laid on using an existing triangular mesh generator based on the Advancing Front Technique subjected to some minor modifications instead of developing a complex strategy for a new quadrilateral mesh generator. The actual discretization is split into three phases. In the first phase, a mixed mesh is created using the augmented triangular mesh generator. This initial mesh could generally contain a large percentage of triangular elements. In the second phase, the initial mesh is subjected to optimization in terms of Laplacian smoothing and topological cleanup. After the second phase, only very low percentage of the triangular elements is present in the mesh. In the third phase, the remaining triangles are eliminated by a one-level refinement applied to the optimized initial mesh. The final mesh is then once more optimized using the Laplacian smoothing. The proposed strategy is capable to produce uniform and graded all-quadrilateral meshes of high quality. The performance of the adopted approach is demonstrated on several examples.
A Comparison of Two Methods For Soft Boolean Operator Interpretation In Information Retrieval
Authors: Edward A. Fox, Sharat Sharan
Venue:  (1986)

Information retrieval systems generally are given Boolean logic queries by users or search intermediaries, in order that an efficient and effective search for relevant documents can be automatically carried out. Previous work with an extended interpretation of Boolean queries has shown that a dramatic improvement in search effectiveness results. Using the P-norm to compute distance from the ideal points in a multi-dimensional space of truth values leads to best results .1 values are on the order of 1 to 4. Other schemes besides the P-norm approach have been proposed in recent years. This paper describes experimental studies aimed at evaluating one family of such methods. In particular, a parameterized fuzzy-logic approach is contrasted with the norm interpretation. Regression analysis supports expected results of parameter settings and gives further insight into why the P-norm scheme is superior.
Machine Descriptions to Build Tools for Embedded Systems
Authors: Norman Ramsey, Jack W. Davidson
Venue:  (1998)

Because of poor tools, developing embedded systems can be unnecessarily hard. Machine descriptions based on register-transfer lists (RTLs) have proven useful in building retargetable compilers, but not in building other retargetable tools. Simulators, assemblers, linkers, debuggers, and profilers are built by hand if at all---previous machine descriptions have lacked the detail and precision needed to generate them. This paper presents detailed and precise machine-description techniques that are based on a new formalization of RTLs. Unlike previous notations, these RTLs have a detailed, unambiguous, and machine-independent semantics, which makes them ideal for supporting automatic generation of retargetable tools. The paper also gives examples of Lambda-RTL, a notation that makes it possible for human beings to read and write RTLs without becoming overwhelmed by machine-dependent detail.
Unwrapping
Authors: David W. Coppit, Kevin J. Sullivan
Venue:  (1998)

A key driver of software obsolescence is change in hardware and system software standards. In the area of software tools, there is now great pressure to host on Intel/Windows platforms tool functions that in the past were typically found in Unix or mainframe environments. In such cases, there can be value in reusing core parts of such legacy systems. Two standard methods for doing this are reengineering and wrapping. Reengineering, being unrestricted in the changes allowed, permits the removal of obsolete parts of a system but creates the risk that changes will break the complex and brittle reused code. Wrapping involves the reuse of existing code without change, but at the cost of including obsolete elements into the new environment. In this paper we propose unwrapping as a new synthesis of these two approaches. To unwrap is to remove unwanted design elements, but with a strong emphasis on leaving core code unchanged. We discuss our preliminary use of this approach to reuse core elements of two Unix-based reliability engineering tools in a modern tool based on package-oriented programming.
AN EXPERIMENTAL COMPARISON OF NEW PROPERTY LIST DESIGNS
Authors: John Panzer, Linda Werner
Venue:  (1995)

Property lists are a common way to display and edit object attributes. They are often organized alphabetically, which can lead to usability problems when the number of properties grows large. Two alternative property list designs, categorical lists and split lists, are presented. An experimental comparison found that categorical lists can reduce selection times by 62% for novice users, while split lists show potential for a 43% reduction.
Bisimulations for Temporal Logic
Authors: N. Kurtonina, M. de Rijke
Venue:  (1996)

We define bisimulations for temporal logic with Since and Until. We compare our notion to existing notions of bisimulations, and we use it to develop the basic model theory of temporal logic with Since and Until, which includes preservation and definability results. We conclude with a brief discussion of the wider applicability of our ideas.
TRIMMING JAVA DOWN TO SIZE
Authors: C. E. McDowell, M. R. Allen, E. A. Baldwin, B. R. Montague, M. Montoreano
Venue:  (1997)

Java is both a programming language and a collection of libraries called packages. Much of the interest in Java is due to the large collection of existing packages which allow complex applications to be built quickly. Perhaps even more important, many programmers find the Java language to be a more desirable language than C or C++, Java''s primary competitors. The advantages of Java apply to any application domain that previously used C or C++, including embedded systems. However, typical Java systems today require 4-8 Mbytes of RAM or more, including those Java systems supplied by traditional embedded systems companies. JavaCam is an embedded Java application that can operate with as little as 1 Mbyte of memory. In this paper we describe how we were able to build a system that runs applications that exercise all of the Java language features in as little as 1 Mbyte of memory.
Embedding Cartesian Products of Graphs into de Bruijn Graphs
Authors: Thomas Andreae, Michael Nolle, Gerald Schreiber
Venue:  (1995)

For Cartesian products G=G_1 times dots times G_m (m geq 2) of nontrivial connected graphs G_i and the n-dimensional base B de Bruijn graph D=D_B(n), we investigate whether or not there exists a spanning subgraph of D which is isomorphic to G. We show that G is never a spanning subgraph of D when n is greater than three or when n equals three and m is greater than two. For n=3 and m=2, we can show for wide classes of graphs that G cannot be a spanning subgraph of D. In particular, these non-existence results imply that D_B(n) never contains a torus (i.e., the Cartesian product of mge2 cycles) as a spanning subgraph when n is greater than two. For n=2 the situation is quite different: we present a sufficient condition for a Cartesian product G to be a spanning subgraph of D=D_B(2). As one of the corollaries we obtain that a torus G=G_1 timesdotstimes G_m is a spanning subgraph of D=D_B(2) provided that |G|=|D| and that the G_i are even cycles of length ge 4. We apply our results to obtain embeddings of relatively small dilation of popular processor networks (as tori, meshes and hypercubes) into de Bruijn graphs of fixed small base.
Toward a Machine Assisted Software Performance Diagnosis Methodology
Authors: Anup Mathur, Marc Abrams
Venue:  (1993)

This paper discusses a methodology for diagnosing performance problems for parallel and distributed programs. The methodology is based on the formation and testing of hypotheses about the cause of performance bottlenecks. The process is illustrated with a case study of an actual problem arising in a parallel discrete event simulation program in which granularity is a primary bottleneck and barrier implementation is a secondary bottleneck. The paper also describes the evolution of Chitra, a software performance measurement and analysis tool whose objective is to automate certain steps in software performance diagnosis.
Braid: Integrating Task and Data Parallelism
Authors: Emily A. West, Andrew S. Grimshaw
Venue:  (1994)

Archetype data parallel or task parallel applications are well served by contemporary languages. However, for applications containing a balance of task and data parallelism the choice of language is less clear. While there are languages that enable both forms of parallelism, e.g., one can write data parallel programs using a task parallel language, there are few languages which support both. We present a set of data parallel extensions to the Mentat Programming Language (MPL) which allow us to integrate task parallelism, data parallelism, and nested task and data parallelism within a single language on top of a single run-time system. The result is an object-oriented language, Braid, that supports both task and data parallelism on MIMD machines. In addition, the data parallel extensions define a language in and of itself which makes a number of contributions to the data parallel programming style. These include subset-level operations (a more general notion of element-level operations), compiler provided iteration within a data parallel data set, and the ability to define complex data parallel operations.
A Fast Non-parametric Density Estimation Algorithm
Authors: Omer Egecioglu
Venue:  (1995)

Non-parametric density estimation is the problem of approximating the values of a probability density function, given samples from the associated distribution. Non-parametric estimation finds applications in discriminant analysis, cluster analysis, and flow calculations based on Smoothed Particle Hydrodynamics. Usual estimators make use of kernel functions, and require on the order of $n^2$ arithmetic operations to evaluate the density at $n$ sample points. We describe a sequence of special weight functions which requires almost linear number of operations in $n$ for the same computation.
PARALLEL ALGORITHMS FOR COMPUTER GRAPHICS
Authors: Cindy Ferguson
Venue:  (1990)

Over the last 10 years advances in hardware and software design have enabled us to obtain more and more realistic computer images. As our capabilities continue to rise so do our expectations. These new demands require high quality imagery in an interactive, real-time environment. One method of achieving this goal is to use parallel processing techniques to generate these images. Parallel algorithms work well for some problems encountered in generating images such as hidden surface removal while for other problems, such as clipping parallel algorithms do not work so well. Possible solutions and problems encountered in applying parallel algorithms will be presented. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
COMPUTING REACHABLE STATES OF PARALLEL PROGRAMS
Authors: David P. Helmbold, Charles E. McDowell
Venue:  (1990)

A concurrency history graph is a representation of the reachable states of a parallel program. A new abstraction for representing the state of a parallel program is presented. This new abstraction is more general than previous work by the authors. At the same time, the new abstraction makes it possible to produce concurrency history graphs that require much less storage than that suggested by a simple worst case complexity analysis. Concurrency history graphs based on this new abstraction form the foundation upon which a static analysis tool capable of detecting race conditions in parallel programs is being built.
An automated approach to quality-aware web applications
Authors: Antonio Ruiz, Rafael Corchuelo, Amador Durán
Venue: Enterprise information systems IV (2003)

Multi-Organisational Web-Based Systems (MOWS) are becoming very popular in the Internet world. It would be desirable for such systems to be quality-aware, and this feature turns the problem of selecting the web services of which they are composed into a complex task. The main reason is that the catalog of available services that meet a set of functional requirements may be quite large, and it is subject to unexpected changes due to the inherent volatility of the Internet. Thus, such systems need an infrastructure able to select the best services at run time so that they can deliver their functionality at the best possible quality level. In this article, we present a proposal that aims at being the core of a run-time system able to support the construction of quality-aware MOWS.