Physical Sciences and Mathematics Commons^™

Adaptive Resonance Associative Map, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

This article introduces a neural architecture termed Adaptive Resonance Associative Map (ARAM) that extends unsupervised Adaptive Resonance Theory (ART) systems for rapid, yet stable, heteroassociative learning. ARAM can be visualized as two overlapping ART networks sharing a single category field. Although ARAM is simpler in architecture than another class of supervised ART models known as ARTMAP, it produces classification performance equivalent to that of ARTMAP. As ARAM network structure and operations are symmetrical, associative recall can be performed in both directions. With maximal vigilance settings, ARAM encodes pattern pairs explicitly as cognitive chunks and thus guarantees perfect storage and recall …

Object Interactions As First Class Objects: From Design To Implementation, Mahesh Dodani, Benjamin Kok Siew Gan, Lizette Velazquez

Research Collection School Of Computing and Information Systems

Collaborations between objects make up the dynamic behavior of OO software. These collaborations among objects require careful design and implementation. Treating the interactions as responsibilities that are integrated in the participating objects, results in tight coupling between objects. Tight coupling increases complexity and reduces reusability. Object interactions need to be first class objects from design to implementation. Our research provides a unified approach to model and implement these interactions as first class objects. During analysis and design, they are modeled using DynaSpecs. During implementation, they are coded with a new language construct called Compositions. DynaSpecs and Compositions provide a consistent …

Finding Connected Components On A Scan Line Array Processor, Ronald I. Greenberg

Computer Science: Faculty Publications and Other Works

This paper provides a new approach to labeling the connected components of an n x n image on a scan line array processor (comprised of n processing elements). Variations of this approach yield an algorithm guaranteed to complete in o(n lg n) time as well as algorithms likely to approach O(n) time for all or most images. The best previous solutions require using a more complicated architecture or require Omega(n lg n) time. We also show that on a restricted version of the architecture, any algorithm requires Omega(n lg n) time in the worst case.

Electric Field Mapping System With Nanosecond Temporal Rosolution, F. E. Peterkin, R. Block, K. H. Schoenbach

Bioelectrics Publications

The electric field dependence of the absorption coefficient in semi‐insulating GaAs at the absorption edge was measured in a high‐voltage pulsed experiment. Pulse duration was kept below 50 ns in order to avoid thermal effects. A GaAs laser diode was used as a probe light source with wavelength varied from 902 to 911 nm. For fields up to 40 kV/cm the absorption coefficient increased from 3 to 17 cm⁻¹ at 902 nm, with smaller absolute increases evident at the longer wavelengths. Calculation from theory was consistent with this behavior. The spatial variation of the electric field was also recorded …

Constrained Least-Squares Digital Image Restoration, Rajeeb Hazra

Dissertations, Theses, and Masters Projects

The design of a digital image restoration filter must address four concerns: the completeness of the underlying imaging system model, the validity of the restoration metric used to derive the filter, the computational efficiency of the algorithm for computing the filter values and the ability to apply the filter in the spatial domain. Consistent with these four concerns, this dissertation presents a constrained least-squares (CLS) restoration filter for digital image restoration. The CLS restoration filter is based on a comprehensive, continuous-input/discrete- processing/continuous-output (c/d/c) imaging system model that accounts for acquisition blur, spatial sampling, additive noise and imperfect image reconstruction. The …

A Delta-F Monte Carlo Method To Calculate Parameters In Plasmas, Maciek Sasinowski

Dissertations, Theses, and Masters Projects

A Monte Carlo code has been developed which very efficiently calculates plasma parameters, such as currents, potentials and transport coefficients for a fully three dimensional magnetic field configuration. The code computes the deviation, f, of the exact distribution function, f, from the Maxwellian, {dollar}F\sb{lcub}M{rcub},{dollar} with {dollar}\psi{dollar} the toroidal magnetic flux enclosed by a pressure surface and H the Hamiltonian. The particles in the simulation are followed with a traditional Monte Carlo scheme consisting of an orbit step in which new values for the positions and momenta are obtained and a collision step in which a Monte Carlo equivalent of the …

Idea Analysis For The Development Of Clinical Trial Strategies, Roberta S. Horowitz

CCE Theses and Dissertations

Idea Analysis was investigated to determine its ability to organize scientific information and explain the results of specialists' deliberations in designing new clinical trials. Ideas have long been recognized as the engine of creativity. By focusing on the capture of ideas from the scientific literature, idea analysis procedures enable the arrangement of the information into forms consistent with those developed by subject specialists. The most obvious example is the concept structure. Ideas containing a common frequently occurring term/phrase can be depicted as a primary node in the concept network. Related terms will appear as elements associated with that node. Ideas …

Large-Scale Client/Server Migration Methodology, A. Steven Krantz

CCE Theses and Dissertations

The purpose of this dissertation is to explain how to migrate a medium-sized or large company to client/server computing. It draws heavily on the recent IBM Boca Raton migration experience. The client/server computing model is introduced and related, by a Business Reengineering Model, to the major trends that are affecting most businesses today, including business process reengineering, empowered teams, and quality management. A recommended information technology strategy is presented. A business case development approach, necessary to justify the large expenditures required for a client/server migration, is discussed. A five-phase migration management methodology is presented to explain how a business can …

A Linear-Time Recognition Algorithm For P4-Reducible Graphs, B. Jamison, S. Olariu

Computer Science Faculty Publications

The P₄-reducible graphs are a natural generalization of the well-known class of cographs, with applications to scheduling, computational semantics, and clustering. More precisely, the P₄-reducible graphs are exactly the graphs none of whose vertices belong to more than one chordless path with three edges. A remarkable property of P₄-reducible graphs is their unique tree representation up to isomorphism. In this paper we present a linear-time algorithm to recognize P₄-reducible graphs and to construct their corresponding tree representation.

Optimizing Object Invocation Using Optimistic Incremental Specialization, Jon Inouye, Andrew P. Black, Charles Consel, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

To make object invocation efficient, it is important to minimize overhead. In general, overhead is incurred in order to maintain transparency; with the advent of mobile computer systems, persistence, increasing security and privacy concerns, transparency becomes more expensive and overhead is increasing. Invocation mechanisms maintain transparency by finding objects, choosing communication media, performing data translation into common formats (e.g., XDR), marshalling arguments, encrypting confidential data, etc. Performing all of these operations on every invocation would lead to unacceptable performance, so designers often avoid operations by specializing object invocation for more restricted environments. For example, the Emerald compiler performs several optimizations …

Production Of Excited Beauty States In Z Decays, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A data sample of about 3.0 million hadronic Z decays collected by the ALEPH experiment at LEP in the years 1991 through 1994, is used to make an inclusive selection of B hadron events.

Linear Time Optimization Algorithms For P4-Sparse Graphs, Beverly Jamison, Stephan Olariu

Computer Science Faculty Publications

Quite often, real-life applications suggest the study of graphs that feature some local density properties. In particular, graphs that are unlikely to have more than a few chordless paths of length three appear in a number of contexts. A graph G is P₄-sparse if no set of five vertices in G induces more than one chordless path of length three. P₄-sparse graphs generalize both the class of cographs and the class of P₄-reducible graphs. It has been shown that P₄-sparse graphs can be recognized in time linear in the size of the …

An Optimal Path Cover Algorithm For Cographs, R. Lin, S. Olariu

Computer Science Faculty Publications

The class of cographs, or complement-reducible graphs, arises naturally in many different areas of applied mathematics and computer science. In this paper, we present an optimal algorithm for determining a minimum path cover for a cograph G. In case G has a Hamiltonian path (cycle) our algorithm exhibits the path (cycle) as well.

Feasible Offset And Optimal Offset For General Single-Layer Channel Routing, Ronald I. Greenberg, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

This paper provides an efficient method to find all feasible offsets for a given separation in a very large-scale integration (VLSI) channel-routing problem in one layer. The previous literature considers this task only for problems with no single-sided nets. When single-sided nets are included, the worst-case solution time increases from $\Theta ( n )$ to $\Omega ( n^2 )$, where n is the number of nets. But if the number of columns c is $O( n )$, the problem can be solved in time $O( n^{1.5} \lg n )$, which improves upon a “naive” $O( cn )$ approach. As a …

A Mathematical Model Of Cycle Chemotherapy, J. C. Panetta, J. Adam

Mathematics & Statistics Faculty Publications

A mathematical model is used to discuss the effects of cycle-specific chemotherapy. The model includes a constraint equation which describes the effects of the drugs on sensitive normal tissue such as bone marrow. This model investigates both pulsed and piecewise-continuous chemotherapeutic effects and calculates the parameter regions of acceptable dose and period. It also identifies the optimal period needed for maximal tumor reduction. Examples are included concerning the use of growth factors and how they can enhance the cell kill of the chemotherapeutic drugs.

Implementation And Evaluation Of Enhanced Areal Interpolation Using Mapinfo And Mapbasic, Gordon Wragg

Theses : Honours

Many researchers today have a need to analyse data in a spatial context. An inherent problem is the mismatch of boundaries between the geographic regions for which data is collected and those regions for which the data is required. Often the solution is to interpolate data from one set of regions to another. This project examines and implements a method of areal interpolation that enables the user to use extra information in areal interpolation to increase the "intelligence ' of the process. This method of Enhanced Areal Interpolation uses a conditional Poisson distribution and the EM algorithm to provide estimated …

Issues In Distributed Control For Atm Networks, Jonathan S. Turner

All Computer Science and Engineering Research

Asynchronous Transfer Mode (ATM) network technology is expected to become a central part of the emerging global information infrastructure. ATM networks introduce a number of features that distinguish them from earlier technologies and introduce new issues in network control. This paper offers a framework for precisely defining and analyzing alternative approaches to the distributed control of ATM networks and explores some of the key design issues through a series of examples. It is hoped that it will provide a useful foundation for researchers in networking and distributed computing interested in exploring these issues further and developing more complete solutions.

Distributed Debugging With I/O Abstraction, Andrew S. Koransky

All Computer Science and Engineering Research

This thesis presents a simple, yet powerful, set of mechanisms for testing and debugging distributed applications consisting of modules that communicate through well-defined data interfaces. The tools allow default or programmer-defined functions to be attached to various communication events so that particular data values at interesting points in the program are made available for testing and debugging. The debugging status of each component of the communication interface can be controlled separately so that various debugging information can be turned on and off during program execution. By attaching breakpoints to programmer-defined fucntions in a standard debugger, fine-grained examination of each module …

Self-Stabilization By Window Washing, Adam M. Costello, George Varghese

All Computer Science and Engineering Research

A useful way to design simple and robust protocols is to make them self-stabilitizing. We describe a new general technique for self-stabilization called window washing. We apply this technique to generalized sliding window protocols that work on a number of topologies. This results in simple, efficient, and self-stabilizing protocols. As far as we know, both window washing and generalized sliding window protocols are new ideas. Our protocols can be used for data links, reliable broadcast, and flow control.

Reasoning About Program Interactions In The Presence Of Mobility, Gruia-Catalin Roman, Peter J. Mccann

All Computer Science and Engineering Research

Mobile computing is emerging as an important new paradigm which has the potential to reshape our thinking about distributed computation. Mobility has far-reaching implications on what designers and users can assume about communication patterns, resource availability, and applciation behaviors as components move from one location to another while joining or leaving groups of other components in their vicinity. New distributed algorithms are likely to be required as the nature of applications shifts with the emergence of this new kind of computing environment. Formal methods have an important role to play in the midst of these developments both in terms of …

Assertional Reasoning About Pairwise Transient Interactions In Mobile Computing, Gruia-Catalin Roman, Peter J. Mccann, Jerome Plun

All Computer Science and Engineering Research

Mobile computing represents a major point of departure from the traditional distributed computing paradigm. The potentially very large number of independent computing units, a decoupled computing style, frequent disconnections, continuous position changes, and the location-dependent nature of the behavior and communication patterns of the individual components present designers with unprecedented challenges in the areas of modularity and dependability. This paper describes two ideas regarding a modular approach to specifying and reasoning about mobile computing. The novelty of our approach rests with the notion of allowing transient interactions among programs which mobe in space. In this paper we restrict our concert …

An Oo Encapsulation Of Lightweight Os Concurrency Mechanisms In The Ace Toolkit, Douglas C. Schmidt

All Computer Science and Engineering Research

This paper describes the design of the ACE object-oriented thread encapsulation class library. The architecture of this class library is presented from an end-user and internal design perspective and several key design issues are discussed. Readers should gain an understanding of the overall design approach as well as the tradeoffs between various software quality factors such as performance, portability, and extensibility.

Error Estimates And Lipschitz Constants For Best Approximation In Continuous Function Spaces, M. Bartelt, W. Li

Mathematics & Statistics Faculty Publications

We use a structural characterization of the metric projection PG(f), from the continuous function space to its one-dimensional subspace G, to derive a lower bound of the Hausdorff strong unicity constant (or weak sharp minimum constant) for PG and then show this lower bound can be attained. Then the exact value of Lipschitz constant for PG is computed. The process is a quantitative analysis based on the Gâteaux derivative of PG, a representation of local Lipschitz constants, the equivalence of local and global Lipschitz constants for lower semicontinuous mappings, and construction …

Using Multiple Statistical Prototypes To Classify Continuously Valued Data, Tony R. Martinez, Dan A. Ventura

Faculty Publications

Multiple Statistical Prototypes (MSP) is a modification of a standard minimum distance classification scheme that generates muItiple prototypes per class using a modified greedy heuristic. Empirical comparison of MSP with other well-known learning algorithms shows MSP to be a robust algorithm that uses a very simple premise to produce good generalization and achieve parsimonious hypothesis representation.

File-System Workload On A Scientific Multiprocessor, David Kotz, Nils Nieuwejaar

Dartmouth Scholarship

No abstract provided.

A Study Of Voluntary Participation In Computer User Groups, Alan Engels

Electronic Theses & Dissertations

The purpose of this study was to determine ways to increase participation of members in Computer User Groups. The problem addressed was that a small select group, less than ten percent, in the Parsons Apple/Macintosh Users Group was doing ninety-five percent or more of the work. If this scenario does not change soon, the overworked and overburdened select few may suffer burnout and quit. Case in point, Joplin, MO, had a large Computer User Group, but about seven years ago, it vanished when the select few refused to serve anymore. The same process of decay and erosion has happened in …

Learning Via Queries With Teams And Anomalies, William I. Gasarch, Efim Kinber, Mark G. Pleszkoch, Carl H. Smith, Thomas Zeugmann

School of Computer Science & Engineering Faculty Publications

Most work in the field of inductive inference regards the learning machine to be a passive recipient of data. In a prior paper the passive approach was compared to an active form of learning where the machine is allowed to ask questions. In this paper we continue the study of machines that ask questions by comparing such machines to teams of passive machines. This yields, via work of Pitt and Smith, a comparison of active learning with probabilistic learning. Also considered are query inference machines that learn an approximation of what is desired. The approximation differs from the desired result …

Software Reliability Issues: An Experimental Approach, Mary Ann Hoppa

Computer Science Theses & Dissertations

In this thesis, we present methodologies involving a data structure called the debugging graph whereby the predictive performance of software reliability models can be analyzed and improved under laboratory conditions. This procedure substitutes the averages of large sample sets for the single point samples normally used as inputs to these models and thus supports scrutiny of their performances with less random input data.

Initially, we describe the construction of an extensive database of empirical reliability data which we derived by testing each partially debugged version of subject software represented by complete or partial debugging graphs. We demonstrate how these data …

Comparing Traditional Statistical Models With Neural Network Models: The Case Of The Relation Of Human Performance Factors To The Outcomes Of Military Combat, William Oliver Hedgepeth

Engineering Management & Systems Engineering Theses & Dissertations

Statistics and neural networks are analytical methods used to learn about observed experience. Both the statistician and neural network researcher develop and analyze data sets, draw relevant conclusions, and validate the conclusions. They also share in the challenge of creating accurate predictions of future events with noisy data.

Both analytical methods are investigated. This is accomplished by examining the veridicality of both with real system data. The real system used in this project is a database of 400 years of historical military combat. The relationships among the variables represented in this database are recognized as being hypercomplex and nonlinear.

The …

The Divided Information Superhighway, Robert Kuttner

Maine Policy Review

This issue marks the introduction of the Margaret Chase Smith Essay, which will be a feature in each issue honoring Sen. Smith by focusing on issues related to citizenship, ethics in government, and integrity as a virtue of public leadership. In this first essay, economist Robert Kuttner asks some important ethical questions about the new world of electronic communications. He suggests that who plays and who pays are very important issues that have not been adequately considered in the highly technical and competitive world that will mark the 21^st century. [This essay originally appeared as a column in the …