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Articles 56221 - 56250 of 57958

Full-Text Articles in Physical Sciences and Mathematics

Sql/Ds, Ingres And Indexes: A Comparative Study Of The Use Of Indexes In Two Database Systems, Karen L. Bourn Jun 1990

Sql/Ds, Ingres And Indexes: A Comparative Study Of The Use Of Indexes In Two Database Systems, Karen L. Bourn

Masters Theses

Many people in data processing desire to know more about the performance of relational databases. Little information about performance exists in the product or public literature. The purpose of this study is to compare one aspect of the performance of relational databases. The aspect explored is the indexing of tables in a relational database. This paper compares the use of indexing in two relational databases, SQL/DS (Ver. 2, Rel. 1) and INGRES (Rel. 5.0/0.6). Queries were created and executed on tables in both databases, first without an index and then with several different indexes.

The findings in this study show …


Development Of A Neural Net Model For The Assignment Problem, Philip Paul Moss Jun 1990

Development Of A Neural Net Model For The Assignment Problem, Philip Paul Moss

Masters Theses

This thesis traces the development of a neural net model which will solve the assignment problem. In addition, the neural net model was compared for optimal performance with four other algorithms: two greedy methods and two well-known solutions, Vogel's Approximation Method (VAM) and the Hungarian method. Assignments were made to randomly generated problems using each method and the results were compared.

The findings from this testing indicated that: (a) the assignments selected by the neural net model were closer to optimal than the two greedy methods and VAM, and (b) the assignments selected by the neural net were not optimal. …


Parallel Implementation Of A Recursive Least Squares Neural Network Training Method On The Intel Ipsc/2, James Edward Steck, Bruce M. Mcmillin, K. Krishnamurthy, M. Reza Ashouri, Gary G. Leininger Jun 1990

Parallel Implementation Of A Recursive Least Squares Neural Network Training Method On The Intel Ipsc/2, James Edward Steck, Bruce M. Mcmillin, K. Krishnamurthy, M. Reza Ashouri, Gary G. Leininger

Computer Science Faculty Research & Creative Works

An algorithm based on the Marquardt-Levenberg least-square optimization method has been shown by S. Kollias and D. Anastassiou (IEEE Trans. on Circuits Syst. vol.36, no.8, p.1092-101, Aug. 1989) to be a much more efficient training method than gradient descent, when applied to some small feedforward neural networks. Yet, for many applications, the increase in computational complexity of the method outweighs any gain in learning rate obtained over current training methods. However, the least-squares method can be more efficiently implemented on parallel architectures than standard methods. This is demonstrated by comparing computation times and learning rates for the least-squares method implemented …


Taxonomies Of Model-Theoretically Defined Topological Properties, Paul Bankston Jun 1990

Taxonomies Of Model-Theoretically Defined Topological Properties, Paul Bankston

Mathematics, Statistics and Computer Science Faculty Research and Publications

A topological classification scheme consists of two ingredients: (1) an abstract class K of topological spaces; and (2) a "taxonomy", i.e. a list of first order sentences, together with a way of assigning an abstract class of spaces to each sentence of the list so that logically equivalent sentences are assigned the same class.K, is then endowed with an equivalence relation, two spaces belonging to the same equivalence class if and only if they lie in the same classes prescribed by the taxonomy. A space X in K is characterized within the classification scheme if whenever Y E …


A Lower Bound On Embedding Large Hypercubes Into Small Hypercubes, Ajay K. Gupta, Alfred J. Boals, Naveed A. Sherwani, Susanne E. Hambrusch May 1990

A Lower Bound On Embedding Large Hypercubes Into Small Hypercubes, Ajay K. Gupta, Alfred J. Boals, Naveed A. Sherwani, Susanne E. Hambrusch

Department of Computer Science Technical Reports

No abstract provided.


Visual Protocol Collection For The Enhancement Of The Radiological Diagnostic Process, Erika Rogers, Ronald C. Arkin, M. Baron, N. Ezquerra, E. Garcia May 1990

Visual Protocol Collection For The Enhancement Of The Radiological Diagnostic Process, Erika Rogers, Ronald C. Arkin, M. Baron, N. Ezquerra, E. Garcia

Computer Science and Software Engineering

This paper describes the Observation Phase of a research project that is designed to explore the nature of visual radiological diagnosis. It is concerned with the collection and analysis of visual protocol data in an effort to determine the salient image features that may impact on the different stages of the diagnostic process, both perceptual and cognitive. These features, once identified, will lead to the formulation of image enhancement hypotheses and the development of knowledge-based visualization techniques to assist the radiological diagnostic process.


Towards Stability Criteria For Multidimensional Distributed Systems: Buffered Aloha Case, Wojciech Szpankowski May 1990

Towards Stability Criteria For Multidimensional Distributed Systems: Buffered Aloha Case, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.


Communication And Control In Spmd Parallel Numerical Computations, Dan C. Marinescu, John R. Rice, E. A. Vavalis May 1990

Communication And Control In Spmd Parallel Numerical Computations, Dan C. Marinescu, John R. Rice, E. A. Vavalis

Department of Computer Science Technical Reports

No abstract provided.


Consistency And Generalization In Incrementally Trained Connectionist Networks, Tony R. Martinez May 1990

Consistency And Generalization In Incrementally Trained Connectionist Networks, Tony R. Martinez

Faculty Publications

This paper discusses aspects of consistency and generalization in connectionist networks which learn through incremental training by examples or rules. Differences between training set learning and incremental rule or example learning are presented. Generalization, the ability to output reasonable mappings when presented with novel input patterns, is discussed in light of the above learning methods. In particular, the contrast between humming distance generalization and generalizing by high order combinations of critical variables is overviewed. Examples of detailed rules for an incremental learning model are presented for both consistency and generalization constraints.


A Direct Access Method Using A Neural Network Model, John William Meyer, George Winston Zobrist May 1990

A Direct Access Method Using A Neural Network Model, John William Meyer, George Winston Zobrist

Computer Science Technical Reports

One of the concerns in computer science involves optimizing usage of machines to make them more efficient and cost effective. One item of particular concern is the use of secondary storage devices, devices that store data other than in the main memory of the computer to which it is attached. The times for searching for data on these devices consistently proves to be a contributing factor in inefficient computer usage.

One data access method that avoids searching when possible is the hashing method. A function is defined to return the record number of a record based on its key field. …


Input Data Pattern Encoding For Neural Net Algorithms, Hyeoncheol Kim, George Winston Zobrist May 1990

Input Data Pattern Encoding For Neural Net Algorithms, Hyeoncheol Kim, George Winston Zobrist

Computer Science Technical Reports

First, a brief overview of neural networks and their applications are described, including the BAM (Bidirectional Associative Memory) model.

A bucket-weight-matrix scheme is proposed, which is a data pattern encoding method that is necessary to transform a set of real-world numbers into neural network state numbers without losing the pattern property the set has. The scheme is designed as a neural net so that it can be combined with other data processing neural nets. The net itself can be used as a bucket-sorting net also. This shows that traditional data structure problems can be an area that neural networks may …


Algorithms And Probabilistic Bounds For The Chromatic Number Of Random Composite Graphs, Jack L. Oakes, Billy E. Gillett May 1990

Algorithms And Probabilistic Bounds For The Chromatic Number Of Random Composite Graphs, Jack L. Oakes, Billy E. Gillett

Computer Science Technical Reports

The composite graph coloring problem (CGCP) is a generalization of the standard graph coloring problem (SGCP). Associated with each vertex is a positive integer called its chromaticity. The chromaticity of a vertex specifies the number of consecutive colors which must be assigned to it.

An exact algorithm for solving the CGCP is presented. The algorithm is a generalization of the vertex-sequential with dynamic reordering approach for the SGCP. It is shown that the method is as effective on composite graphs as its counterpart is on standard graphs. Let X̅(CGnp) and X̅(SGnp) denote, respectively, the mean chromatic …


Software Validation Techniques : A Contrast Between Myers' And Hetzel's Techniques, Reyad I. Abukaker May 1990

Software Validation Techniques : A Contrast Between Myers' And Hetzel's Techniques, Reyad I. Abukaker

Electronic Dissertations and Theses

This research work presents the contemporary testing methodologies of current state-of-the-art methodologies in software testing. Myers' and Hetzel's methodologies are the primary objectives of this research. The scope of this work is to contrast these two testing methodologies, through looking at their principles as well as their definitions of testing. The two definitions of testing differ substantially. Myers' philosophy deals with human psychology and economics as the primary factors in defining the test plans. Hetzel's philosophy is broad in that it looks at software testing in terms of "meeting requirements." However, Hetzel focuses toward "evaluating" and "measuring" a software system …


Monotone Logic Programming, Howard A. Blair, Allen Brown Jr., V. S. Subrahmanian May 1990

Monotone Logic Programming, Howard A. Blair, Allen Brown Jr., V. S. Subrahmanian

Electrical Engineering and Computer Science - Technical Reports

We propose a notion of an abstract logic. Based on this notion, we define abstract logic programs to be sets of sentences of an abstract logic. When these abstract logics possess certain logical properties (some properties considered are compactness, finitariness, and monotone consequence relations) we show how to develop a fixed-point, model-state-theoretic and proof theoretic semantics for such programs. The work of Melvin Fitting on developing a generalized semantics for multivalued logic programming is extended here to arbitrary abstract logics. We present examples to show how our semantics is robust enough to be applicable to various non-classical logics like temporal …


Korean Character Recognition Using Neural Networks, Jinhwan Koh, G. S. Moon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka May 1990

Korean Character Recognition Using Neural Networks, Jinhwan Koh, G. S. Moon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

We present a neural-network approach for recognizing printed Korean characters. Our approach is based on a variant of the back-propagation algorithm. The results indicate that by transforming the character data into Hough space, we can achieve excellent recognition.


A Logic Grammar Foundation For Document Representation And Document Layout, Allen Brown Jr., Howard A. Blair May 1990

A Logic Grammar Foundation For Document Representation And Document Layout, Allen Brown Jr., Howard A. Blair

Electrical Engineering and Computer Science - Technical Reports

We present a powerful grammar-based paradigm for electronic document markup: coordinated definite clause translation grammars. This markup is of a declarative character, being, in effect, a collection of constraints on the logical and physical structure of documents. To the best of our knowledge, coordinated grammars and their parsers can accommodate all of the descriptive and layout processing functionality enjoyed by extant electronic markup languages. We describe an operational prototype that demonstrates the feasibility of a syntax-directed basis for formalizing and realizing document layout.


Forecasting Sunspot Numbers Using Neural Networks, Ming Li, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka May 1990

Forecasting Sunspot Numbers Using Neural Networks, Ming Li, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

A recurrent connectionist network has been designed to model sunspot data. Preliminary experimental work shows that the network can produce competitive results as compared to traditional autoregressive models. The method is not problem specific and could be applied to other problems in dynamical system modeling, recognition, prediction, and control fields. It is observed that statistical methods can be used to design an appropriate neural network architecture.


On Choosing An Optimally Trimmed Mean, Kishan Mehrotra, Paul Jackson, Anton Schick May 1990

On Choosing An Optimally Trimmed Mean, Kishan Mehrotra, Paul Jackson, Anton Schick

Electrical Engineering and Computer Science - Technical Reports

In this paper we revisit the problem of choosing an optimally trimmed mean. This problem was originally addressed by Jaeckel (1971). We propose alternatives to Jaeckel's estimator and its modifications discussed in Andrews et al. (1972). Jaeckel's procedure chooses the optimal trimming by minimizing an estimate of the asymptotic variance of the trimmed mean. We use the bootstrap procedure to choose the optimal trimming. A simulation study shows that our procedure compares favorably with Jaeckel's procedure. We also discuss modification of our procedure to the two sample setting.


A Lexical Extension Of Montague Semantics, William C. Purdy May 1990

A Lexical Extension Of Montague Semantics, William C. Purdy

Electrical Engineering and Computer Science - Technical Reports

This paper presents a model theory of lexical semantics that is compatible with theories in the Montagovian tradition. Lexical expressions are modeled as subsets or “subspaces” in a “semantic spaces”. A unique representation is defined for subspaces of the semantic space. This unique representation is called the "normal form" of the lexical denotation. A Boolean algebra of normal forms is developed, in which lexical entailment is Boolean inclusion. The presentation in the body of the paper is informal, making use of examples to illustrate the theory and to indicate the range of applicability. Formal definitions and proofs in support of …


A Neural Network Simulator For The Connnection Machine, N. Asokan, Ravi V. Shankar, Chilukuri K. Mohan, Kishan Mehrotra, Sanjay Ranka May 1990

A Neural Network Simulator For The Connnection Machine, N. Asokan, Ravi V. Shankar, Chilukuri K. Mohan, Kishan Mehrotra, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

In this paper we describe the design, development, and performance of a neural network simulator for the Connection Machine (CM)3. The design of the simulator is based on the Rochester Connectionist Simulator(RCS). RCS is a simulator for connectionist networks developed at the University of Rochester. The CM simulator can be used as a stand-alone system or as a high-performance parallel back-end to RCS. In the latter case, once the network has been built by RCS, the high-performance parallel back-end system constructs an equivalent network on the CM processor array and executes it. The CM simulator facilitates the exploitation of the …


Simplifications To "A New Approach To The Covering Radius...”, H. F. Mattson Jr May 1990

Simplifications To "A New Approach To The Covering Radius...”, H. F. Mattson Jr

Electrical Engineering and Computer Science - Technical Reports

We simplify the proofs of four results in [3], restating two of them for greater clarity. The main purpose of this note is to give a brief transparent proof of Theorem 7 of [3], the main upper bound of that paper. The secondary purpose is to give a more direct statement and proof of the integer programming determination of covering radius of [3]. Theorem 7 of [3] follows from a simple result in [2], which we state with the notation (for the linear code A).


Dynamic Range Partitioning In Multiprocessor Database Implementations, Ophir Frieder May 1990

Dynamic Range Partitioning In Multiprocessor Database Implementations, Ophir Frieder

Electrical Engineering and Computer Science - Technical Reports

Multiprocessor implementation of the relational database operators has recently received great attention in literature [1-4, 8, 11]. As the complexity of implementing the relational operators rests on the inter-node communication patterns involved in an operation, greater research attention has been focused on Join algorithms. The Join traffic patterns subsume those of the remaining relational operators. To effectively exploit parallelism in bucket based join implementations, the domain of the joining attributes must be partitioned into equal subranges. That is, the processing of each subrange requires roughly the same amount of time. A skewed distribution of workload significantly hinders performance. As relations …


Optical Switching And Routing Architectures For Fiber-Optic Computer Communication Networks, Alok Choudhary, Salim Hariri, Wang Song, Partha Banerjee, Sanjay Ranka May 1990

Optical Switching And Routing Architectures For Fiber-Optic Computer Communication Networks, Alok Choudhary, Salim Hariri, Wang Song, Partha Banerjee, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

Optical technology has become a significant part of communication networks. We propose an Optical Interface Message Processor (OPTIMP) that exploits high-bandwidth, parallelism, multi-dimensional capability, and high storage density offered by optics. The most time consuming operations such as switching and routing in communication networks are performed in optical domain in the proposed system. Our design does not suffer from the optical/electrical conversion bottlenecks and can perform switching and routing in the range of Gigabits/s. The proposed design can have significant impact in high-speed communication networks as well as high-speed interconnection networks for parallel computers. The source-destination (S-D) information from a …


Strong Completeness Results For Paraconsistent Logic Programming, Howard A. Blair, V. S. Subrahmanian May 1990

Strong Completeness Results For Paraconsistent Logic Programming, Howard A. Blair, V. S. Subrahmanian

Electrical Engineering and Computer Science - Technical Reports

In [6], we introduced a means of allowing logic programs to contain negations in both the head and the body of a clause. Such programs were called generally Horn programs (GHPs, for short). The model-theoretic semantics of GHPs were defined in terms of four-valued Belnap lattices [5]. For a class of programs called well-behaved programs, an SLD-resolution like proof procedure was introduced. This procedure was proven (under certain restrictions) to be sound (for existential queries) and complete (for ground queries). In this paper, we remove the restriction that programs be well-behaved and extend our soundness and completeness results to apply …


Arrays And The Lambda Calculus, Klaus Berkling May 1990

Arrays And The Lambda Calculus, Klaus Berkling

Electrical Engineering and Computer Science - Technical Reports

Why do functional languages have more difficulties with arrays than procedural languages? The problems arising in the designing of functional languages with arrays and in their implementations are manifold. They can be classified according to 1) first principles, 2) semantics, 3) pragmatics, and 4) performance. This paper attempts to give an outline of the issues in this area, and their relation to the lambda calculus. The lambda calculus is a formal system and as such seemingly remote from practical applications. However, specific representations and implementations of that system may be utilized to realize arrays such that progress is made towards …


Parallel Sparse: Data Structure And Organization, Mo Mu, John R. Rice May 1990

Parallel Sparse: Data Structure And Organization, Mo Mu, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.


Building Solid Models From Polygonal Data, George Vanecek May 1990

Building Solid Models From Polygonal Data, George Vanecek

Department of Computer Science Technical Reports

No abstract provided.


Btc Test Methodology, Gaurav Garg May 1990

Btc Test Methodology, Gaurav Garg

All Computer Science and Engineering Research

This paper describes the testing methodology for the Broadcast Translation Circuit. It covers logic simulation, timing simulation, and a single push-button test for the device. The document is intended to be a supplement to documents WUCS-89-52 and WUCS-90-19, which outline the design of the BTC in full details. The intent of a push-button test is to have a single test that causes the device to process every type of packets that it could receive. This would include various combination of RC and OP fields, a test that examines every table entry thoroughly, as well as a test of the parity …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, May 1990, College Of Engineering And Computer Science, Wright State University May 1990

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, May 1990, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A four page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


Interactive Morphometrics From Three-Dimensional Surface Images, William A. Barrett, Shawn C. Becker May 1990

Interactive Morphometrics From Three-Dimensional Surface Images, William A. Barrett, Shawn C. Becker

Faculty Publications

Techniques have been developed for extracting three-dimensional (3D) measurements directly and interactively from 3D representations of surface anatomy. In order to obtain 3D measurements the anatomical surface is interrogated directly through the use of morphometric tools. Morphometric tools include points, 3D graphical "probes", and logical sectioning functions which interact with the surface through depth buffer compositing operations. Tools are interactively positioned on or through the surface to measure surface dimensions and partial volumes, or to define intersecting functions which allow surface anatomy to be visualized in the context of surrounding anatomy. Visualization is also enhanced because tools reveal much pertaining …