ppxscal/embedding_network huggingface dataset:
MDBS: A Modeling and Database System to Support Research in the Earth Sciences
Authors: Terence R. Smith, Jianwen Su, Divyakant Agrawal, Amr El Abbadi
Venue:  (1993)

An interdisciplinary team of computer scientists and EOS earth-science investigators is jointly investigating the concept of a modeling and database system} (MDBS). MDBS is intended to support large-scale earth science investigations by complementing EOS-DIS in terms of support for high-level modeling and data management. In particular, MDBS is intended to facilitate the iterative development of scientific models in data-intensive and computationally intensive applications. It is based on a simple characterization of scientific activity and on an advanced data model that together capture the essence of scientific modeling and database activities in terms of large lattices of representational domains and associated transformations that are employed to organize scientific knowledge, data and algorithms. A high-level, declarative modeling and database language (MDBL) that is based on this data model and on four fundamental sets of scientific operations provides support for scientific modeling activities and for easy access to distributed databases of datasets and algorithms. It permits the efficient resuse of code for building new algorithms and supports key aspects of scientific modeling activities, such as lineage and error tracking in datasets, and for the concepts of model and project. We are applying a version of MDBS in order to solve several earth science research problems that have arisen in EOS investigations.
An Introduction to the Layered Characterisation for High Performance Systems
Authors: E. Papaefstathiou, D. J. Kerbyson, G. R. Nudd, T. J. Atherton, J. S. Harper
Venue:  (1997)

A toolset for performance analysis of parallel systems, PACE, is presented in this report. In this toolset expert knowledge about the performance evaluation techniques is not required as a prerequisite for the user. Instead a declarative approach to the performance study is taken by describing the application in a way that is both intuitive to the user, but can also be used to obtain performance results. The underlying performance related characterisation models and their evaluation processes are hidden from the user. This document describes the special purpose language, and the evaluation system, that form the core of the PACE toolset. Amongst the aims of the toolset is the support of characterisation model reusability, ease of experimentation, provide different levels of prediction accuracy, and support of different levels of characterisation model abstraction.
Using Group and Subsystem Level Analysis to Validate Software Metrics on Commercial Software Systems
Authors: Dennis G. Kafura, James Canning
Venue:  (1988)

This paper reports the results of a study which examined the relationship between a collection of software metrics and the development data (such as errors and coding time) of three commercially produced software systems. The software metrics include both measures of system interconnectivity and measures of system code. This study revealed strong relationships between the metrics and the development data when individual components were aggregated by structure (into subsystems) or by similarity (into groups). The subsystem and group results imply that research and application of metrics should be focused above the component level. The group results also imply that metrics can guide the effective application of project resources by identifying those groups which, for example, will contain a disproportionately large fraction of errors. Finally, the study showed the overall utility of two interconnectivity metrics: Henry and Kafura''s information flow metric and McClure''s invocation metric. This result is significant because interconnectivity metrics can be applied early in the life cycle.
Compiling Functional Programming Constructs to a Logic Engine
Authors: Harvey Abramson, Peter Ludemann
Venue:  (1986)

In this paper we consider how various constructs used in functional programming can be efficiently translated to code for a Prolog engine (designed by L\"{u}demann) similar in spirit but not identical to the Warren machine. It turns out that this Prolog engine which contains a delay mechanism designed to permit coroutining and sound implementation of negation is sufficient to handle all common functional programming constructs; indeed, such a machine has about the same efficiency as a machine designed specifically for a functional programming language. This machine has been fully implemented.
Adaptive Quadratic Neural Nets
Authors: Sok G Lim, M. Alder, P. Hadingham
Venue:  (1991)

Abstract unavailable.
The Evaluation of Software Quality: An Empirical Approach to Validation
Authors: James D. Arthur, Richard E. Nance
Venue:  (1992)

This interim report outlines activities related to the Software Quality Assessment Project funded by the JLC/CRM. Reported activities reflect investigative efforts performed at the Systems Research Center (Virginia Tech) and at the Melpar Division of E-Systems. Accordingly, this report discusses (1) the development and installation of a document analyzer, (2) the development and refinement of document quality and process indicators, and (3) our approach to data collection. An outline of planned activities for the next reporting period is also 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
CLASSIFYING NETWORKS: WHEN CAN TWO ANONYMOUS NETWORKS COMPUTE THE SAME VECTOR-VALUED FUNCTIONS?
Authors: Nancy C. Norris
Venue:  (1994)

An "anonymous network" is a computer network in which all processors run the same algorithm during a computation. We will consider two classifications of anonymous networks: Networks will be called "f-equivalent" if the set of vector-valued functions each can anonymously compute is the same, and "p-equivalent" if the set of functions each can compute is the same, "up to a permutation" We first give a characteriz- ation of the vector-valued functions a given network can anonymously compute. This extends a result due to Yamashita and Kameda characterizing the scalar-valued functions a network can compute. Next, we develop algebraic and graph-theoretic techniques for handling edge-labeled digraphs. We will use these techniques, along with results from algebraic automata theory and permutation group theory, to derive a polynomial-time algorithm for determining whether two networks are f-equivalent. This will yield a polynomial-time algorithm for determining whether two edge-labeled digraphs have the same lattice of quotient-graph isomorphisms, and will let us conclude that classifying networks by what they can compute is easy. Classifying networks by "p-equivalence" on the other hand, is likely to be a much harder problem. We will present a polynomial-time transformation of the group-isomorphism problem to the problem of "p-equivalence" As of this writing, the best known algorithm solves group-isomorphism in order n to the log n steps, for a group of order n. 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
Web Response Time and Proxy Caching
Authors: Liu Binzhang, Abdulla Ghaleb, Johnson Tommy, Fox Edward A.
Venue:  (1998)

It is critical to understand WWW latency in order to design better HTTP protocols. In this paper we characterize Web response time and examine effects of proxy caching on response time. We show that at least a quarter of the total elapsed time is spent in setting up TCP connections. We also characterize the effect of a user''s network bandwidth on response time. Average connection time from a client via a 33.6 K modem is two times longer than that from a client via switched Ethernet. Contrary to the typical thought about Web proxy caching, this study finds that a single stand alone proxy cache does not always reduce response time. Implications of these results to the HTTP-NG protocol and Web application design also are discussed in the paper.
Toward a Formal Specification of Menu-based Systems
Authors: James D. Arthur
Venue:  (1986)

As software systems continue to increase in sophistication and complexity, so do the interface requirements that support the corresponding user interaction. To select the proper '' '' nd of ingredients that constitutes an adequate user interface, it is essential that the system designer have a firm understanding of the interaction process, i.e, how the selected dialogue format interacts with the user and with the underlying task software. To promote such an understanding, this paper presents a model that characterizes one particular dialogue for menu-based interaction. This model is actually a sequence of models, hierarchically structured, where each successive model builds on its predecessor by introducing additional characterization elements. The first model describes the minimal set of elements inherent to any menu-based interface; successive models extend this minimal set by introducing task actions, incremental history sequences, and frame-associated memory. These principal model elements enable the characterization of fundamental, menu-based operations like computational and decision processes, user response reversal, and user directed movement. Moreover, because the principal model elements correspond directly to real world objects, an intuitive as well as formal understanding of menu-based interaction can be achieved. Effectively, the model elements and the hierarchical structure imposed by these elements provide and ideal environment for characterizing and classifying menu-based systems at various levels of sophistication. 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
An Empirical Study of Representation Methods for Reusable SoftwareComponents
Authors: William Frakes, T. Pole
Venue:  (1994)

An empirical study of methods for representing reusable software components is described. Thirty-five subjects searched for reusable components in a database of UNIX tools using four different representation methods: attribute-value, enumerated, faceted, and keyword. The study used Proteus, a reuse library system that supports multiple representation methods. Searching effectiveness was measured with recall, precision, and overlap. Search time for the four methods was also compared. Subjects rated the methods in terms of preference and helpfulness in understanding components. Some principles for constructing reuse libraries, based on the results of this study, are discussed.
An O(N log N) Expected Time Merge Heuristic for the Planar ETSP
Authors: Ritu Chadha, Donald C. S. Allison
Venue:  (1988)

We discuss a new heuristic for solving the Euclidean Traveling Salesman Problem (ETSP). This heuristic is a convex hull-based method and makes use of the Delaunay triangulation of the set of cities to compute a tour for the given set of cities. We conjecture that the expected running time for this algorithm is O(N log N), implying that a new and faster ETSP heuristic is now available.
Multiparent recombination in evolutionary computing
Authors: A. E. Eiben
Venue: Advances in evolutionary computing: theory and applications (2003)

This chapter considers multiparent reproduction, where more than two parents are involved in creating offspring. First we give a survey of multiparent operators that have been introduced over the years in evolutionary computing and we reformulate the traditional mutation-or-crossover debate in the light of such operators. Second, we present some existing results on the usefulness of multiparent operators. We conclude the chapter with a look at future developments and some suggestions for further research.
Implementation of Out-of-Core Cholesky and QR Factorizations with POOCLAPACK
Authors: Brian C. Gunter, Wesley Reiley, Robert A. van de Geijn
Venue:  (2000)

In this paper parallel implementation of out-of-core Cholesky factorization is used to introduce the Parallel Out-of-Core Linear Algebra Package (POOCLAPACK), a flexible infrastructure for parallel implementation of out-of-core linear algebra operations. POOCLAPACK builds on the Parallel Linear Algebra Package (PLAPACK) for in-core parallel dense linear algebra computation. Despite the extreme simplicity of POOCLAPACK, the out-of-core Cholesky factorization implementation is shown to achieve in excess of 80% of peak performance on a 64 node configuration of the Cray T3E-600. The insights gained from examining the Cholesky factorization have been applied to the much more difficult and important QR factorization operation. Preliminary results for parallel implementation of the resulting OOC QR factorization algorithm are included.
Determining Timing Properties of Infinite Real-Time Programs
Authors: Abha Moitra, M. Joseph
Venue:  (1991)

This paper describes a method for determining whether timing deadlines over the commands of a real-time program will be satisfied during execution. A program is assumed to consist of a fixed number of nonterminating processes, each having a simple cyclic structure. Processes may contain nondeterministic commands and may intercommunicate synchronously or asynchronously. Each command has an execution time which takes any value from a non-empty real interval. There are infinitely many possible executions of such a program, and each execution is of infinite length. And if the program P has n processes, it may be implemented on any system with m processors, 1 2 m 2 n. We show how this set of executions can be reduced to a finite set, R-Exe-m(P) of finite length executions, and then prove that any deadline that is violated in any infinite execution will be violated in one of these finite executions. Thus the feasibility of executing the infinite program P on m processors can be determined by examination of the set R-Exe-m(p) of executions of P.
A Genetic Algorithm Approach to Cluster Analysis
Authors: Cowgill Marc C., Harvey Robert J., Watson Layne T.
Venue:  (1998)

A common problem in the social and agricultural sciences is to find clusters in experimental data; the standard attack is a deterministic search terminating in a locally optimal clustering. We propose here a genetic algorithm (GA) for performing cluster analysis. GAs have been used profitably in a variety of contexts in which it is either impractical or impossible to directly solve for a globally optimal solution to complex numerical problems. In the present case, our GA clustering technique attempted to maximize a variance-ratio (VR) based goodness-of-fit criterion defined in terms of external cluster isolation and internal cluster homogeneity. Although our GA-based clustering algorithm cannot guarantee to recover the cluster solution that exhibits the global maximum of this fitness function, it does explicitly work toward this goal (in marked contrast to existing clustering algorithms, especially hierarchial agglomerative ones such as Ward''s method). Using both constrained and unconstrained simulated datasets, Monte Carlo results showed that in some conditions the genetic clustering algorithm did indeed surpass the performance of conventional clustering techniques (Ward''s and K-means) in terms of an internal (VR) criterion. Suggestions for future refinement and study are offered.
Knowledge-Based Visual Interpretation Using Declarative Schemata
Authors: Roger A. Browse
Venue:  (1982)

One of the main objectives of computer vision systems is to produce structural descriptions of the scenes depicted in images. Knowledge of the class of objects being imaged can facilitate this objective by providing models to guide interpretation, and by furnishing a basis for the structural descriptions. This document describes research into techniques for the representation and use of knowledge of object classes, carried out within the context of a computational vision system which interprets line drawings of human-like body forms. .br A declarative schemata format has been devised which represents structures of image features which constitute dep- ictions of body parts. The system encodes relations between these image constructions and an underlying three dimensional model of the human body. Using the component hierarchy as a structural basis, two layers of representation are developed. One references the fine resolution features, and the other references the coarse resolution. These layers are connected with links representative of the specialization/generalization hierarchy. The problem domain description is declarative, and makes no commitment to the nature of the subsequent interpretation processes. As a means of testing the adequacy of the representation, portions have been converted into a PROLOG formulation and used to ``prove'''' body parts in a data base of assertions about image properties. .br The interpretation phase relies on a cue/model approach, using an extensive cue table which is automatically generated from the problem domain description. The primary mechanisms for control of interpretation possibilities are fashioned after network consistency methods. The operation of these mechanisms is localized and separated between operations at the feature level and at the model level. .br The body drawing interpretation system is consistent with aspects of human visual perception. The system is capable of intelligent selection of processing locations on the basis of the progress of interpretation. A dual resolution retina is moved about the image collecting fine level features in a small foveal area and coarse level features in a wider peripheral area. Separate interpretations are developed locally on the basis of the two different resolution levels, and the relation between these two interpretations is analyzed by the system to determine locations of potentially useful information.
Multi-Agent Systems: A Risk to Freedom
Authors: I. D. Craig
Venue:  (1996)

Multi-agent systems are being proposed for a number of contexts where autonomous agents are required to act in concert with other agents and with other software in order to perform certain tasks. For example, it has been proposed that autonomous software agents be employed to gather information from the Internet: these agents would acess databases and bulletin boards, collecting information that is of potential relevence and sending to other agents who determine its true relevance. There is a clear sense in which agents can be used to restrict civil liberties: one can forsee, for example, agents being used in surveillance of citizens, particularly when television, telephone and computer are connected. Given the increasingly computerised nature of the world and the increasing number of networked systems, such information gathering becomes a real possibility. There are the possibilities for restricting freedom of movement, freedom of choice, freedom of thought. It becomes possible for an unscrupulous agency to tamper with records with the effect that one simply disappears - literally becomes a non-person.
A STARTER TOOLKIT FOR MODELING WITH IMPLICIT SURFACES
Authors: Jim Kleck
Venue:  (1990)

Implicit Surfaces offer an immense amount of power in modeling. The set of all mathematical and procedural functions is a fertile field which contains (or closely approximates) every shape imaginable. Despite this, implicit surfaces have not been extensively used in modeling. This is in part due to the difficulty of shaping implicit surfaces. This paper presents a starter set of functions that can help in the shaping of implicit surfaces. 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
Convergence of Trust Region Augmented Lagrangian Methods Using Variable Fidelity Approximation Data
Authors: Rodriguez Jose F., Renaud John E., Watson Layne T.
Venue:  (1997)

To date the primary focus of most constrained approximate optimization strategies is that application of the method should lead to improved designs. Few researchers have focused on the development of constrained approximate optimization strategies that are assured of converging to a Karush-Kuhn-Tucker (KKT) point for the problem. Recent work by the authors based on a trust region model management strategy has shown promise in managing the convergence of constrained approximate optimization in application to a suite of single level optimization test problems. Using a trust-region model management strategy, coupled with an augmented Lagrangian approach for constrained approximate optimization, the authors have shown in application studies that the approximate optimization process converges to a KKT point for the problem. The approximate optimization strategy sequentially builds a cumulative response surface approximation of the augmented Lagrangian which is then optimized subject to a trust region constraint. In this research the authors develop a formal proof of convergence for the response surface approximation based optimization algorithm. Previous application studies were conducted on single level optimization problems for which response surface approximations were developed using conventional statistical response sampling techniques such as central composite design to query a high fidelity model over the design space. In this research the authors extend the scope of application studies to include the class of multidisciplinary design optimization (MDO) test problems. More importantly the authors show that response surface approximations constructed from variable fidelity data generated during concurrent subspace optimizations (CSSOs) can be effectively managed by the trust region model management strategy. Results for two multidisciplinary test problems are presented in which convergence to a KKT point is observed. The formal proof of convergence and the successfull MDO application of the algorithm using variable fidelity data generated by CSSO are original contributions to the growing body of research in MDO.
Programming Principles for the Semantics of the Semantics of Programs
Authors: W. M. Beynon
Venue:  (1992)

Fundamental concerns of relevance to programming are raised by Brian Smith in [19]. These focus on the relation that holds between a program and the world outside - the semantics of what is referred to by computer scientists as the semantics of the program. This paper explains how programming concepts developed by the author in collaboration with others may contribute to "a theoretical framework that does justice to practice" such as is discussed in [19].