ppxscal/embedding_network huggingface dataset:
Derandomized Vector Sorting
Authors: Heath Lenwood S., Mateescu Gabriel
Venue:  (1998)

An instance of the vector sorting problem is a sequence of k-dimensional vectors of length n. A solution to the problem is a permutation of the vectors such that in each dimension the length of the longest decreasing subsequence is O(sqrt(n)). A random permutation solves the problem. Here we derandomize the obvious probabilistic algorithm and obtain a deterministic O(kn^3.5) time algorithm that solves the vector sorting problem. We also apply the algorithm to a book embedding problem.
PTOM - A Pascal Translator For Mobile Code
Authors: Christian F. Tschudin
Venue:  (1996)

We report on an implementation of a PASCAL translator that generates code for mobile software messengers (agents): these agents can roam a network of interconnected execution platforms on behalf of a user, enabling users to implement customized network functionality themselves. In this report we focus on the language extensions (PASCAL-M) and the implementation aspects of the translator. The main departure in PASCAL-M from standard PASCAL is that the programmer has access to the generated code in form of string constants. An interesting aspect of the PASCAL- to (PTOM) translator is that PASCAL-M is translated to the stack-based high-level language M0. M0 is similar to PostScript and has no notion of memory addresses although PASCAL compilers usually produce code for machines or software interpreters with word addressable memory: because M0 completely hides the exact memory locations of code as well as data, we have to use other implementation approaches for activation frames, variable dereferencing and code fixups. Other aspects of the translator implementation like data mapping and heap management are also described. Finally, we relate our work to recent developments in the field of intermediate code and languages.
A Probabilistic Neural Network Edge detector for 2 Dimensional Gray Scale Images
Authors: Anthony Zaknich, Yianni Attikiouzel
Venue:  (1991)

A Probabilistic Neural NEtwork (PNN) classifier is used to design an edge detection algorithm for 2 dimensional gray scale images of rocks. It is shown hos a very sparse training set made up of a small number of example vectors is sufficient to generalise the edge detection around each and every rock. The data is also applied to the Backpropagation Neural Network (BON) classifier for comparison. Many industrial image processing problems for which it is difficult to develop a priori processing rules can be solved conveniently in a similar way.
Statistical Characterization of Wide-Area Self-Similar Network Traffic
Authors: Matthew T. Lucas, Dallas E. Wrege, Bert J. Dempsey, Alfred Weaver
Venue:  (1996)

Background traffic models are fundamental to packet-level network simulation since the background traffic impacts packet drop rates, queuing delays, end-to-end delay variation, and also determines available network bandwidth. In this paper, we present a statistical characterization of wide-area traffic based on a week-long trace of packets exchanged between a large campus network, a state-wide educational network, and a large Internet service provider. The results of this analysis can be used to provide a basis for modeling background load in simulations of wide-area packet-switched networks such as the Internet, contribute to understanding the fractal behavior of wide-area network utilization, and provide a benchmark to evaluate the accuracy of existing traffic models. The key findings of our study include the following: (1) both the aggregate and its component substreams exhibit significant long-range dependencies in agreement with other recent traffic studies, (2) the empirical probability distributions of packet arrivals are log-normally distributed, (3) packet sizes exhibit only short-term correlations, and (4) the packet size distribution and correlation structure are independent from both network utilization and time of day.
Aslantest User''s Manual
Authors: Jeffrey G. Douglas
Venue:  (1994)

Aslantest is a symbolic execution tool for the formal specification language Aslan. Aslan is a state-based specification language built on first-order predicate calculus with equality. Aslantest animates Aslan specifications and enables users to interactively run specific test cases or symbolically execute the specification. This document is the user''s manual for the Aslantest system, outlining its features and commands.
Implementation Concepts for an Extensible Data Model and Data Language
Authors: Don S. Batory, T. Y. Leung
Venue:  (1986)

Future database systems must feature extensible data models and data languages in order to accommodate the novel data types and special-purpose operations that are required by nontraditional database applications. In this paper, we outline a functional data model and data language that are targeted for the semantic interface of GENESIS, an extensible DBMS. The model and language are generalizations of FQL [Bun82] and DAPLEX [Shi81], and have an implementation that fits ideally with the modularity required by extensible database technologies. We explore different implementations of functional operators and present experimental evidence that they have efficient implementations. We also explain the advantages of a functional front-end to 1NF databases, and show how our language and implementation are being used to process queries on both 1NF and 1NF relations.
When Do Match-compilation Heuristics Matter?
Authors: Kevin Scott, Norman Ramsey
Venue:  (2000)

Modern, statically typed, functional languages define functions by pattern matching. Although pattern matching is defined in terms of sequential checking of a value against one pattern after another, real implementations translate patterns into automata that can test a value against many patterns at once. Decision trees are popular automata. The cost of using a decision tree is related to its size and shape. The only method guaranteed to produce decision trees of minimum cost requires exponential match-compilation time, so a number of heuristics have been proposed in the literature or used in actual compilers. This paper presents an experimental evaluation of such heuristics, using the Standard ML of New Jersey compiler. The principal finding is that for most benchmark programs, all heuristics produce trees with identical sizes. For a few programs, choosing one heuristic over another may change the size of a decision tree, but seldom by more than a few percent. There are, however, machine-generated programs for which the right or wrong heuristic can make enormous differences: factors of 2-20.
MULTIVIEW: AN INTEGRATED APPROACH TO VISUALIZATION OF PARALLEL PROGRAMS (M.S. Thesis)
Authors: Cynthia H Ferguson
Venue:  (1990)

Multiview is an integrated tool for visualizing the execution of a parallel program. The design of Multiview was motivated by the idea that the current tools used to visualize parallel programs did not provide enough views for the user to get a complete understanding of her program. Multiview attempts to solve this problem with an extensible object-oriented design. A prototype system was built and its implementation is described.
The Design of a Distributed Interpreter for Concurrent Prolog
Authors: Chun M Tam
Venue:  (1984)

Prolog is a programming language based on predicate logic. Its successor, Concurrent Prolog, was designed to meet the needs of a multiprocessing environment to the extent that it may be desirable as a succinct language for writing operating systems. Here, we demonstrate the feasibllity of implementing a distributed interpreter for Concurrent Prolog using traditional programming tools under a multiprocess structuring methodology. We will discuss the considerations that must be made in a distributed environment and how the constructs of the language may be implemented. In particular, several subtle pitfalls associated with the implementation of read-only variables and the propagation of new bindings will be illustrated. In addition, a modification to Shapiro''s treatment of read-only variables is proposed in an attempt to ``clean up'''' the semantics of the language. (The discussion will centre around a primitive version of an interpreter for the language written in Zed (a language similar to C) on an Unix-like operating system, Verex. Although a brief introduction of Prolog and Concurrent Prolog will be given, it is assumed that the reader is familiar with the paper \underline{A Subset of Concurrent Prolog and Its Interpreter} by E.Y. Shapiro [Shapiro83].)
Hierarchical Arc Consistency: Exploiting Structured Domains in Constraint Satisfaction Problems
Authors: Alan K. Mackworth, Jan A. Mulder, William S. Havens
Venue:  (1985)

Constraint satisfaction problems can be solved by network consistency algorithms that eliminate local inconsistencies before constructing globa1 solutions. We describe a new algorithm that is useful when the variable domains can be structured hierarchically into recursive subsets with common properties and common relationships to subsets of the domain values for related variables. The algorithm, HAC, uses a technique known as hierarchical arc consistency. Its performance is analyzed theoretically and the conditions under which it is an improvement are outlined. The use of HAC in a program for understanding sketch maps, Mapsee3, is briefly discussed and experimental results consistent with the theory are reported.
Event-Based Video Analysis,
Authors: L. Zelnik-Manor, M. Irani
Venue:  (2001)

Dynamic events can be regarded as long-term temporal objects, which are characterized by spatio-temporal features at multiple temporal scales. Based on this, we design a simple statistical distance measure between video sequences (possibly of different lengths) based on their behavioral content. This measure is non-parametric and can thus handle a wide range of dynamic events. We use this measure for isolating and clustering events within long continuous video sequences. This is done without prior knowledge of the types of events, their models, or their temporal extent. An outcome of such a clustering process is a temporal segmentation of long video sequences into event-consistent sub-sequences, and their grouping into event-consistent clusters. Our event representation and associated distance measure can also be used for event-based indexing into long video sequences, even when only one short example-clip is available. However, when multiple example-clips of the same event are available (either as a result of the clustering process, or given manually), these can be used to refine the event representation, the associated distance measure, and accordingly the quality of the detection and clustering process.
An Input Normal Form Homotopy for the L2 Optimal Model Order Reduction Problem
Authors: Yuzhen Ge, Emmanuel G. Collins, Layne T. Watson, L. D. Davis
Venue:  (1993)

In control system analysis and design, finding a reduced order model, optimal in the L-squared sense, to a given system model is a fundamental problem. The problem is very difficult without the global convergence of homotopy methods, and a homotopy based approach has been proposed. The issues are the number of degrees of freedom, the well posedness of the finite dimensional optimization problem, and the numerical robustness of the resulting homotopy algorithm. A homotopy algorithm based on the input normal form characterization of the reduced order model is developed here and is compared with the homotopy algorithms based on Hyland and Bernstein''s optimal projection equations. The main conclusions are that the input normal form algorithm can be very efficient, but can also be very ill conditioned or even fail.
The Topology of Partial Metric Spaces
Authors: S. G. Matthews
Venue:  (1992)

The T0 world of Scott''s topological models used in the denotational semantics of programming languages may at first sight appear to have nothing whatever in common with the Hausdorff world of metric space theory. Can this be true though when the notion of "distance" is so important in the application of inductive proof theory to recursive definitions? This paper shows that existing work on the application of quasi metrics to denotational semantics can be taken much further than just describing Scott topologies. Using our "partial metric" we introduce a new approach by constructing each semantic domain as an Alexandrov topology "sandwiched" between two metric topologies. to be presented at the Eighth Summer Conference on General Topology and Applications, June 18-20 1992, Queens College, New York City. 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
Approximating Polygons and Subdivisions with Minimum-Link Paths
Authors: Leonidas J. Guibas, John E. Hershberger, Joseph S. B. Mitchell, Jack S Snoeyink
Venue:  (1992)

We study several variations on one basic approach to the task of simplifying a plane polygon or subdivision: Fatten the given object and construct an approximation inside the fattened region. We investigate fattening by convolving the segments or vertices with disks and attempt to approximate objects with the minimum number of line segments, or withem near the minimum, by using efficient greedy algorithms. We give some variants that have linear or $O (n \log n)$ algorithms approximating polygonal chains of {\em n} segments, and show that for subdivisions or chains with no self-intersections it is {\em NP}-hard to compute the best approximation.
Distributed Control Parallelism in Multidisciplinary Aircraft Design
Authors: Krasteva Denitza T., Watson Layne T., Baker Chuck, Grossman Bernard, Mason William H., Haftka Raphael T.
Venue:  (1998)

Multidisciplinary design optimization (MDO) for large-scale engineering problems poses many challenges (e.g., the design of an efficient concurrent paradigm for global optimization based on disciplinary analyses, expensive computations over vast data sets, etc.) This work focuses on the application of distributed schemes for massively parallel architectures to MDO problems, as a tool for reducing computation time and solving larger problems. The specific problem considered here is configuraton optimization of a high speed civil transport (HSCT), and the efficient parallelization of the embedded paradigm for reasonable design space identification. Two distributed dynamic load balancing techniques (random polling and global round robin with message combining) and two necessary termination detection schemes (global task count and token passing) were implemented and evaluated in terms of effectiveness and scalability to large problem sizes and a thousand processors. The effect of certain parameters on execution time was also inspected. Empirical results demonstrated stable performance and effectiveness for all schemes, and the parametric study showed that the selected algorithmic parameters have a negligible effect on performance.
Specifying Logic Programs in Controlled Natural Language
Authors: Norbert E. Fuchs, Rolf Schwitter
Venue:  (1995)

Writing specifications for computer programs is not easy since one has to take nto account the disparate conceptual worlds of the application domain and of software development. To bridge this conceptual gap we propose controlled natural language as a declarative and application-specific specification language. Controlled natural language is a subset of natural language that can be accurately and efficiently processed by a computer, but is expressive enough to allow natural usage by non-specialists. Specifications in controlled natural language are automatically translated into Prolog clauses, hence become formal and executable. The translation uses a definite clause grammar (DCG) enhanced by feature structures. Inter-text references of the specification, e.g. anaphora, are resolved with the help of discourse representation theory (DRT). The generated Prolog clauses are added to a knowledge base. We have implemented a prototypical specification system that successfully processes the specification of a simple automated teller machine.
Dynamic buckling of columns considering shear deformation and rotary inertia
Authors: M. Ghorashi
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

In this paper, the critical load of columns has been investigated by the consideration of shear deformation and rotary inertia. Such an analysis is essential for performing proper evaluation of buckling load of columns made of composite materials and thick columns that are shear sensitive. Both static and dynamic buckling of columns is investigated. It is shown that the shear deformation effect always tends to reduce the buckling load. In this way, ignoring shear deformation in the case of thick columns or columns made of shear sensitive materials would result in unsafe designs. The shear deformation effect is observed to be the same for the static and dynamic loadings, at least for simply supported columns. The consideration of rotary inertia proved that for simply supported columns this phenomenon has no effect on the buckling load.
Random Interval Graphs
Authors: Nicholas Pippenger
Venue:  (1997)

We consider models for random interval graphs that are based on stochastic service systems, with vertices corresponding to customers and edges corresponding to pairs of customers that are in the system simultaneously. The number N of vertices in a connected component thus corresponds to the number of customers arriving during a busy period, while the size K of the largest clique (which for interval graphs is equal to the chromatic number) corresponds to the maximum number of customers in the system during a busy period. We obtain the following results for both the M/D/Infinity and the M/M/Infinity models, with arrival rate lambda per mean service time. The expected number of vertices is e^lambda, and the distribution of the N/e^lambda tends to an exponential distribution with mean 1 as lambda tends to infinity. This implies that log N is very strongly concentrated about lambda-gamma (where gamma is Euler''s constant), with variance just pi^2/6. The size K of the largest clique is very strongly concentrated about e lambda. Thus the ratio K/log N is strongly concentrated about e, in contrast with the situation for random graphs generated by unbiased coin flips, where K/log N is very strongly concentrated about 2/log 2.
Commutativity Analysis: A New Analysis Framework for Parallelizing Compilers
Authors: Martin Rinard, Pedro Diniz
Venue:  (1996)

This paper presents a new analysis technique, commutativity analysis, for automatically parallelizing computations that manipulate dynamic, pointer-based data structures. Commutativity analysis views the computation as composed of operations on objects. It then analyzes the program at this granularity to discover when operations commute (i.e. generate the same final result regardless of the order in which they execute). If all of the operations required to perform a given computation commute, the compiler can automatically generate parallel code. We have implemented a prototype compilation system that uses commutativity analysis as its primary analysis framework. We have used this system to automatically parallelize two complete scientific computations: the Barnes-Hut N-body solver and the Water code. This paper presents performance results for the generated parallel code running on the Stanford DASH machine. These results provide encouraging evidence that commutativity analysis can serve as the basis for a successful parallelizing compiler.
Accelerated Access to Shared Distributed Arrays on Distributed Memory Systemsby Access Objects
Authors: Stefan Lupke
Venue:  (1994)

In case of algorithms with non-local data access patterns virtual shared memory implementations commonly result in a huge lack of performance because of virtual shared memory latency. In order to avoid this problem, a system providing access to distributed data structures has been developed, implemented as a C++ object library. By means of this library the programmer may use special access objects as agents to access the distributed data structures. In case of accessing arrays these access objects may be buffers or queues. If the algorithms are suited for using these access objects, the communication bandwidth instead of the com munication latency becomes the major performance factor.
Initializing the EM Algorithm for use in Gaussian Mixture Modelling
Authors: Patricia McKenzie, Mike Alder
Venue:  (1993)

We look at the EM algorithm used for Gaussian Mixture Modelling and problems with its initialization. We then consider a method of initializing the algorithm to cluster centers called the Dog Rabbit Strategy and compare this to the k-means clustering algorithm. The Dog Rabbit Strategy and the EM algorithm is run on data produced from an industrial pattern recognition problem and some results are discussed. This file cannot be viewed with ghostview - please use pageview.
A Distributed Genetic Algorithm with Migration for the Design of Composite Laminate Structures
Authors: McMahon Mathew T., Watson Layne T.
Venue:  (1998)

This paper describes the development of a general Fortran 90 framework for the solution of composite laminate design problems using a genetic algorithm (GA). The initial Fortran 90 module and package of operators result in a standard genetic algorithm (sGA). The sGA is extended to operate on a parallel processor, and a migration algorithm is introduced. These extensions result in the distributed genetic algorithm with migration (dGA). The performance of the dGA in terms of cost and reliability is studied and compared to a sGA baseline, using two types of composite laminate design problems. The nondeterminism of GAs and the migration and dynamic load balancing algorithm used in this work result in a changed (diminished) workload, so conventional measures of parallelizability are not meaningful. Thus, a set of experiments is devised to characterize the run time performance of the dGA.
The Lim-Alder Algorithm for Extended Edge Extraction
Authors: Patrick C Hew, Mike Alder
Venue:  (1998)

The Lim-Alder Extended Edge Extraction Algorithm accumulates pixels into ``natural'''' lines and curves. The Algorithm works from locally smooth pixel sequences, and does not require prior models about the appearance of the curves or lines. This tutorial presentation gives enough detail for implementation.