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Articles 52621 - 52650 of 58244

Full-Text Articles in Physical Sciences and Mathematics

Performance Analysis Of Mobile Agents For Filtering Data Streams On Wireless Networks, David Kotz, Guofei Jiang, Robert Gray, George Cybenko, Ronald A. Peterson Aug 2000

Performance Analysis Of Mobile Agents For Filtering Data Streams On Wireless Networks, David Kotz, Guofei Jiang, Robert Gray, George Cybenko, Ronald A. Peterson

Dartmouth Scholarship

Wireless networks are an ideal environment for mobile agents, because their mobility allows them to move across an unreliable link to reside on a wired host, next to or closer to the resources they need to use. Furthermore, client-specific data transformations can be moved across the wireless link, and run on a wired gateway server, with the goal of reducing bandwidth demands. In this paper we examine the tradeoffs faced when deciding whether to use mobile agents to support a data-filtering application, in which numerous wireless clients filter information from a large data stream arriving across the wired network. We …


Adapting To The Information Age, Jens G. Pohl Jul 2000

Adapting To The Information Age, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper draws attention to the profound changes that human civilization is experiencing as it moves from an industrial environment into an information environment, in which unprecedented emphasis is placed on the knowledge and capabilities of the individual. A clear distinction is drawn between data and information in relationship to computer-based facilities, and the transition of data-processing to the higher levels of information and knowledge representation in quasi intelligent decision-support systems. It is argued that the cultivation of its human capital becomes a foundational requirement for the success of a knowledge-based organization. In such an organization traditional practices of hierarchical, …


An Inference Engine-Based Subscription Service, Kym J. Pohl, Jens G. Pohl Jul 2000

An Inference Engine-Based Subscription Service, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

A Distributed Network Architecture (DNA) forms the basis of many decision-support systems available today. Such architecture excels at providing an application environment rich in transparency, performance, and expandability (Gray and Lievano 1997). However, efforts at the Collaborative Agent Design (CAD) Research Center in San Luis Obispo, California have found that for this architecture to be successfully applied to agent-based, decision-support systems two additional ingredients must be present, namely a query service and a subscription service. These two mechanisms support the extensive collaboration inherent in agent-based, decision-support systems. Although primarily utilized as a means of agent-to-agent interaction these two services can …


Rescaling The Energy Function In Hopfield Networks, Tony R. Martinez, Xinchuan Zeng Jul 2000

Rescaling The Energy Function In Hopfield Networks, Tony R. Martinez, Xinchuan Zeng

Faculty Publications

In this paper we propose an approach that rescales the distance matrix of the energy function in the Hopfield network for solving optimization problems. We rescale the distance matrix by normalizing each row in the matrix and then adjusting the parameter for the distance term. This scheme has the capability of reducing the effects of clustering in data distributions, which is one of main reasons for the formation of invalid solutions. We evaluate this approach through a large number (20,000) simulations based on 200 randomly generated city distributions of the 10-city traveling salesman problem. The result shows that, compared to …


The Inefficiency Of Batch Training For Large Training Sets, Tony R. Martinez, D. Randall Wilson Jul 2000

The Inefficiency Of Batch Training For Large Training Sets, Tony R. Martinez, D. Randall Wilson

Faculty Publications

Multilayer perceptrons are often trained using error backpropagation (BP). BP training can be done in either a batch or continuous manner. Claims have frequently been made that batch training is faster and/or more "correct" than continuous training because it uses a better approximation of the true gradient for its weight updates. These claims are often supported by empirical evidence on very small data sets. These claims are untrue, however, for large training sets. This paper explains why batch training is much slower than continuous training for large training sets. Various levels of semi-batch training used on a 20,000-instance speech recognition …


Engineering Access Control For Distributed Enterprise Applications, Konstantin Beznosov Jul 2000

Engineering Access Control For Distributed Enterprise Applications, Konstantin Beznosov

FIU Electronic Theses and Dissertations

Access control (AC) is a necessary defense against a large variety of security attacks on the resources of distributed enterprise applications. However, to be effective, AC in some application domains has to be fine-grain, support the use of application-specific factors in authorization decisions, as well as consistently and reliably enforce organization-wide authorization policies across enterprise applications. Because the existing middleware technologies do not provide a complete solution, application developers resort to embedding AC functionality in application systems. This coupling of AC functionality with application logic causes significant problems including tremendously difficult, costly and error prone development, integration, and overall ownership …


Examples, Counterexamples, And Enumeration Results For Foldings And Unfoldings Between Polygons And Polytopes, Erik D. Demaine, Martin L. Demaine, Anna Lubiw, Joseph O'Rourke Jul 2000

Examples, Counterexamples, And Enumeration Results For Foldings And Unfoldings Between Polygons And Polytopes, Erik D. Demaine, Martin L. Demaine, Anna Lubiw, Joseph O'Rourke

Computer Science: Faculty Publications

We investigate how to make the surface of a convex polyhedron (a polytope) by folding up a polygon and gluing its perimeter shut, and the reverse process of cutting open a polytope and unfolding it to a polygon. We explore basic enumeration questions in both directions: Given a polygon, how many foldings are there? Given a polytope, how many unfoldings are there to simple polygons? Throughout we give special attention to convex polygons, and to regular polygons. We show that every convex polygon folds to an infinite number of distinct polytopes, but that their number of combinatorially distinct gluings is …


Integration And Querying Of Heterogeneous, Autonomous, Distributed Database Systems, Rukshan Indika Athauda Jul 2000

Integration And Querying Of Heterogeneous, Autonomous, Distributed Database Systems, Rukshan Indika Athauda

FIU Electronic Theses and Dissertations

Today, databases have become an integral part of information systems. In the past two decades, we have seen different database systems being developed independently and used in different applications domains. Today's interconnected networks and advanced applications, such as data warehousing, data mining & knowledge discovery and intelligent data access to information on the Web, have created a need for integrated access to such heterogeneous, autonomous, distributed database systems. Heterogeneous/multidatabase research has focused on this issue resulting in many different approaches. However, a single, generally accepted methodology in academia or industry has not emerged providing ubiquitous intelligent data access from heterogeneous, …


Dimensionality Reduction Using Genetic Algorithms, Michael L. Raymer, William F. Punch, Erik D. Goodman, Leslie A. Kuhn, Anil K. Jain Jul 2000

Dimensionality Reduction Using Genetic Algorithms, Michael L. Raymer, William F. Punch, Erik D. Goodman, Leslie A. Kuhn, Anil K. Jain

Kno.e.sis Publications

Pattern recognition generally requires that objects be described in terms of a set of measurable features. The selection and quality of the features representing each pattern affect the success of subsequent classification. Feature extraction is the process of deriving new features from original features to reduce the cost of feature measurement, increase classifier efficiency, and allow higher accuracy. Many feature extraction techniques involve linear transformations of the original pattern vectors to new vectors of lower dimensionality. While this is useful for data visualization and classification efficiency, it does not necessarily reduce the number of features to be measured since each …


A New Fixed-Point Theorem For Logic Programming Semantics, Anthony K. Seda, Pascal Hitzler Jul 2000

A New Fixed-Point Theorem For Logic Programming Semantics, Anthony K. Seda, Pascal Hitzler

Computer Science and Engineering Faculty Publications

We present a new fixed-point theorem akin to the Banach contraction mapping theorem, but in the context of a novel notion of generalized metric space, and show how it can be applied to analyse the denotational semantics of certain logic programs. The theorem is obtained by generalizing a theorem of Priess-Crampe and Ribenboim, which grew out of applications within valuation theory, but is also inspired by a theorem of S.G. Matthews which grew out of applications to conventional programming language semantics. The class of programs to which we apply our theorem was defined previously by us in terms of operators …


Path Planning For Planar Articulated Robots Using Configuration Spaces And Compliant Motion, Elisha Sacks Jul 2000

Path Planning For Planar Articulated Robots Using Configuration Spaces And Compliant Motion, Elisha Sacks

Department of Computer Science Technical Reports

No abstract provided.


Cryptanalysis Of The M-Permutation Protection Schemes, Hongjun Wu, Feng Bao, Dingfeng Ye, Robert H. Deng Jul 2000

Cryptanalysis Of The M-Permutation Protection Schemes, Hongjun Wu, Feng Bao, Dingfeng Ye, Robert H. Deng

Research Collection School Of Computing and Information Systems

Anderson and Kuhn have proposed the EEPROM modification attack to recover the secret key stored in the EEPROM. At ACISP ’98, Fung and Gray proposed an m-permutation protection scheme against the EEPROM modification attack. At ACISP ’99, Fung and Gray pointed out that in their original scheme, a secret key with too small or too large Hamming weight could be recovered easily. Then they proposed a revised m- permutation protection scheme and claimed that their revised scheme does not leak any information of the secret key. In this paper, we break completely both the original and the revised …


Is Information Systems A Science? An Inquiry Into The Nature Of The Information Systems Discipline, Deepak Khazanchi, Bjørn Erik Munkvold Jul 2000

Is Information Systems A Science? An Inquiry Into The Nature Of The Information Systems Discipline, Deepak Khazanchi, Bjørn Erik Munkvold

Information Systems and Quantitative Analysis Faculty Publications

The Information Systems (IS) discipline is apparently undergoing an identity crisis. Academicians question the need for IS departments in colleges stating the absence of a core for the field and its integration within other business functions as a basis for its elimination. At the same time, many practitioners, as reflected in the US government's recent IT labor shortage report, continue to ignore IS as a distinct field of study. This article briefly outlines these and other challenges and argues that notwithstanding underlying philosophical differences, it can be concluded that IS is an emerging scientific discipline. This conclusion is reached through …


Almost Block Diagonal Linear Systems: Sequential And Parallel Solution Techniques, And Applications, P. Amodio, J.R. Cash, G. Roussos, R.W. Wright, G. Fairweather, I. Gladwell, G.L. Kraut, M. Paprzycki Jul 2000

Almost Block Diagonal Linear Systems: Sequential And Parallel Solution Techniques, And Applications, P. Amodio, J.R. Cash, G. Roussos, R.W. Wright, G. Fairweather, I. Gladwell, G.L. Kraut, M. Paprzycki

Faculty Publications

Almost block diagonal (ABD) linear systems arise in a variety of contexts, specifically in numerical methods for two-point boundary value problems for ordinary differential equations and in related partial differential equation problems. The stable, efficient sequential solution of ABDs has received much attention over the last fifteen years and the parallel solution more recently. We survey the fields of application with emphasis on how ABDs and bordered ABDs (BABDs) arise. We outline most known direct solution techniques, both sequential and parallel, and discuss the comparative efficiency of the parallel methods. Finally, we examine parallel iterative methods for solving BABD systems. …


Roughening, Deroughening, And Nonuniversal Scaling Of The Interface Width In Electrophoretic Deposition Of Polymer Chains, Frank W. Bentrem, Ras B. Pandey, Fereydoon Family Jul 2000

Roughening, Deroughening, And Nonuniversal Scaling Of The Interface Width In Electrophoretic Deposition Of Polymer Chains, Frank W. Bentrem, Ras B. Pandey, Fereydoon Family

Faculty Publications

Growth and roughness of the interface of deposited polymer chains driven by a field onto an impenetrable adsorbing surface are studied by computer simulations in (2 + 1) dimensions. The evolution of the interface width W shows a crossover from short-time growth described by the exponent beta(1) to a long-time growth with exponent beta(2) (>beta(1)) Tne saturated width increases, i.e., the interface roughens, with the molecular weight L-c, but the roughness exponent alpha (from W-s similar to L-alpha) becomes negative in contrast to models for particle deposition; cr depends on the chain length-a nonuniversal scaling with the substrate length …


Trading Risk In Mobile-Agent Computational Markets, Jonathan Bredin, David Kotz, Daniela Rus Jul 2000

Trading Risk In Mobile-Agent Computational Markets, Jonathan Bredin, David Kotz, Daniela Rus

Dartmouth Scholarship

Mobile-agent systems allow user programs to autonomously relocate from one host site to another. This autonomy provides a powerful, flexible architecture on which to build distributed applications. The asynchronous, decentralized nature of mobile-agent systems makes them flexible, but also hinders their deployment. We argue that a market-based approach where agents buy computational resources from their hosts solves many problems faced by mobile-agent systems. \par In our earlier work, we propose a policy for allocating general computational priority among agents posed as a competitive game for which we derive a unique computable Nash equilibrium. Here we improve on our earlier approach …


Buckets: Smart Objects For Digital Libraries, Michael L. Nelson Jul 2000

Buckets: Smart Objects For Digital Libraries, Michael L. Nelson

Computer Science Theses & Dissertations

Discussion of digital libraries (DLs) is often dominated by the merits of various archives, repositories, search engines, search interfaces and database systems. While these technologies are necessary for information management, information content and information retrieval systems should progress on independent paths and each should make limited assumptions about the status or capabilities of the other. Information content is more important than the systems used for its storage and retrieval. Digital information should have the same long-term survivability prospects as traditional hardcopy information and should not be impacted by evolving search engine technologies or vendor vagaries in database management systems.

Digital …


Design Of Adaptive Sliding Mode Fuzzy Control For Robot Manipulator Based On Extended Kalman Filter, Abdelrahman Aledhaibi Jul 2000

Design Of Adaptive Sliding Mode Fuzzy Control For Robot Manipulator Based On Extended Kalman Filter, Abdelrahman Aledhaibi

Mechanical & Aerospace Engineering Theses & Dissertations

In this work, a new adaptive motion control scheme for robust performance control of robot manipulators is presented. The proposed scheme is designed by combining the fuzzy logic control with the sliding mode control based on extended Kalman filter. Fuzzy logic controllers have been used successfully in many applications and were shown to be superior to the classical controllers for some nonlinear systems. Sliding mode control is a powerful approach for controlling nonlinear and uncertain systems. It is a robust control method and can be applied in the presence of model uncertainties and parameter disturbances, provided that the bounds of …


A Flowchart Structure For Modification Of A Modsim Process Model, Murali K. Adatrao Jul 2000

A Flowchart Structure For Modification Of A Modsim Process Model, Murali K. Adatrao

Electrical & Computer Engineering Theses & Dissertations

There are many software processes and software development models that support the development of a software model prior to implementation. However, more often than not, these practices are not followed resulting in a lack of documentation of the intended functionality of the software. As a result, software often becomes a black box for later developers. Even a simple bug fix can turn into an exhaustive task for the developers, as they must attempt to infer the intended system behavior. New designers cannot make any changes to the software or extend the software behavior, as the underlying model within the software …


Routing Optimization Through Computer-Aided Simulation, Madhusudhan Akundi Jul 2000

Routing Optimization Through Computer-Aided Simulation, Madhusudhan Akundi

Electrical & Computer Engineering Theses & Dissertations

Routing has always been a challenging field, and the various techniques of mathematics and operations research have been developed. For commercial organizations, routing has begun to receive extensive attention because of the savings gained in terms of time, money, personnel, and the transportation fleet by developing optimized routing networks. Until recently, it was difficult to develop optimized networks due to the computational difficulties of the problem. However, with the advancement in computer technology and processing speeds, it has become possible to simulate a large number of routing scenarios and determine optimal solutions for a given set of constraints. Not only …


The Complexity Of Planning With Partially-Observable Markov Decision Processes, Martin Mundhenk Jun 2000

The Complexity Of Planning With Partially-Observable Markov Decision Processes, Martin Mundhenk

Computer Science Technical Reports

This work surveys results on the complexity of planning under uncertainty. The planning model considered is the partially-observable Markov decision process. The general planning problems are, given such a process, (a) to calculate its performance under a given control policy, (b) to find an optimal or approximate optimal control policy, and (c) to decide whether a good policy exists. The complexity of this and related problems depend on a variety of factors, including the observability of the process state, the compactness of the process representation, the type of policy, or even the number of actions relative to the number of …


Ria: Selecting Information To Include In Cooperative Task — Oriented Dialogues, Elise H. Turner Jun 2000

Ria: Selecting Information To Include In Cooperative Task — Oriented Dialogues, Elise H. Turner

University of Maine Office of Research Administration: Grant Reports

The goal of this project was to delevop a technique for selecting information to volunteer in problem solving dialogues. The technique was to create usefulness ratings for information based on the problem solving of the agent that may communicate the information. Heuristics translate specific problem solving activities into contributions to the overall usefulness rating for the information. To this end, our objectives included determining the type of information that should be included in dialogues and implementing heuristics.


Personal Radio, John C. Artz Jr Jun 2000

Personal Radio, John C. Artz Jr

Dartmouth College Undergraduate Theses

With the development of new technologies that allow the broadcast of digital data over radio signals, there are many possibilities for improving upon the traditional radio station model for content delivery. The idea of Personal Radio is a system that tailors content to meet the needs of each individual. Using Global Positioning System (GPS) technology to play location specific content, the listening history to play content an appropriate number of times, and user feedback to learn personal preferences, the Personal Radio provides the listener with the content that is the most useful/interesting to them. This paper will examine the general …


An Economic Cpu-Time Market For D'Agents, Ezra E.K. Cooper Jun 2000

An Economic Cpu-Time Market For D'Agents, Ezra E.K. Cooper

Dartmouth College Undergraduate Theses

A usable and efficient resource-management system has been created for use with D'Agents. The software dynamically negotiates a price rate for CPU time, using the competitive bids of mobile agents that offer currency in return for fast computation. The system allows mobile agents to plan their expenditures across many hosts while minimizing the time needed for their tasks. The ability to price CPU time opens the door for service owners to be compensated for the computation consumed by agents and provides an incentive for servers to allow anonymous agents. We discuss the theoretical background which makes a CPU market system …


Registration Of Images With Dissimilar Contrast Using A Hybrid Method Employing Correlation And Mutual Information, Karolyn A. Abram Jun 2000

Registration Of Images With Dissimilar Contrast Using A Hybrid Method Employing Correlation And Mutual Information, Karolyn A. Abram

Dartmouth College Undergraduate Theses

The problem of fitting one image into another is commonly called "registration." Finding the best possible translation and rotation necessary to align two images is one approach to solving this problem. Registration is a crucial component of many remote sensing and medical image interpretation applications. Image alignment techniques aid in volumetric estimations of complicated structures and allow radiologists to accurately identify changes between sequential images. Radiologists require image alignment capabilities to correct for patient motion and/or content displacement between images. Numerous image registration techniques exist for correcting the alignment problems mentioned above. Unfortunately, most of these techniques, such as Correlation, …


Hybrid Probabilistic Programs, Alex Dekhtyar, V. S. Subrahmanian Jun 2000

Hybrid Probabilistic Programs, Alex Dekhtyar, V. S. Subrahmanian

Computer Science and Software Engineering

The precise probability of a compound event (e.g. e1 V e2,e1 Ʌ e2) depends upon the known relationships (e.g. independence, mutual exclusion, ignorance of any relationship, etc.) between the primitive events that constitute the compound event. To date, most research on probabilistic logic programming has assumed that we are ignorant of the relationship between primitive events. Likewise, most research in AI (e.g. Bayesian approaches) has assumed that primitive events are independent. In this paper, we propose a hybrid probabilistic logic programming language in which the user can explicitly associate, with any given probabilistic strategy, a conjunction and disjunction operator, and …


Learning From One Example Through Shared Densities On Transform, Erik Learned-Miller, N Matsakis, Paul Viola Jun 2000

Learning From One Example Through Shared Densities On Transform, Erik Learned-Miller, N Matsakis, Paul Viola

Erik G Learned-Miller

We define a process called congealing in which elements of a dataset (images) are brought into correspondence with each other jointly, producing a data-defined model. It is based upon minimizing the summed component-wise (pixel-wise) entropies over a continuous set of transforms on the data. One of the biproducts of this minimization is a set of transform, one associated with each original training sample. We then demonstrate a procedure for effectively bringing test data into correspondence with the data-defined model produced in the congealing process. Subsequently; we develop a probability density over the set of transforms that arose from the congealing …


Neptune: Un Logiciel Pour Les Écoulements De Rivière, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier Jun 2000

Neptune: Un Logiciel Pour Les Écoulements De Rivière, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier

Alexandre Martin

Une méthodologie de conception et d'analyse est développée pour la simulation des écoulements clans les rivières. La discrétisation des équations de base (Saint-Venant) est établie en fonction du schéma de Roe, développé à l'origine pour des écoulements compressibles non-visqueux. Le domaine est discrétisé en espace avec des triangles ou quadrilatères, clans un contexte de volume-finis, ce qui permet de représenter des géométries complexes. L'imposition des conditions frontières et initiales sont aussi décrites. Toutes les étapes préliminaires à la résolution du problème, ainsi que la visualisation de la solution sont gérées par la famille de logiciels PLANÈTES.


Hiding Association Rules By Using Confidence And Support, Elena Dasseni, Vassilios S. Verkios, Ahmed K. Elmagarmid, Elisa Bertino Jun 2000

Hiding Association Rules By Using Confidence And Support, Elena Dasseni, Vassilios S. Verkios, Ahmed K. Elmagarmid, Elisa Bertino

Department of Computer Science Technical Reports

No abstract provided.


Justifying Electronic Banking Network Expansion Using Real Option Pricing: An Empirical Illustration, Michel Benaroch, Robert J. Kauffman Jun 2000

Justifying Electronic Banking Network Expansion Using Real Option Pricing: An Empirical Illustration, Michel Benaroch, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

The application of real options analysis to information technology investment evaluation problems recently has been proposed in the IS literature (Chalasani et al. 1997; Dos Santos 1991; Kambil et al. 1993; Kumar 1996; Taudes 1998). The research reported on in this paper illustrates the value of applying real options analysis in the context of a case study involving the deployment of point-of-sale (POS) debit services by the Yankee 24 shared electronic banking network of New England. In the course of so doing, the paper also attempts to operationalize real options analysis concepts by examining claimed strengths of this analysis approach …