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Articles 1861 - 1890 of 2014
Full-Text Articles in Physical Sciences and Mathematics
Mapping Of Portable Parallel Programs, Song Chen
Mapping Of Portable Parallel Programs, Song Chen
Dissertations
An efficient parallel program designed for a parallel architecture includes a detailed outline of accurate assignments of concurrent computations onto processors, and data transfers onto communication links, such that the overall execution time is minimized. This process may be complex depending on the application task and the target multiprocessor architecture. Furthermore, this process is to be repeated for every different architecture even though the application task may be the same. Consequently, this has a major impact on the ever increasing cost of software development for multiprocessor systems. A remedy for this problem would be to design portable parallel programs which …
Document Preprocessing And Fuzzy Unsupervised Character Classification, Shy-Shyan Chen
Document Preprocessing And Fuzzy Unsupervised Character Classification, Shy-Shyan Chen
Dissertations
This dissertation presents document preprocessing and fuzzy unsupervised character classification for automatically reading daily-received office documents that have complex layout structures, such as multiple columns and mixed-mode contents of texts, graphics and half-tone pictures. First, the block segmentation algorithm is performed based on a simple two-step run-length smoothing to decompose a document into single-mode blocks. Next, the block classification is performed based on the clustering rules to classify each block into one of the types such as text, horizontal or vertical lines, graphics, and pictures. The mean white-to-black transition is shown as an invariance for textual blocks, and is useful …
Visual Pattern Recognition Using Neural Networks, Jenlong Moh
Visual Pattern Recognition Using Neural Networks, Jenlong Moh
Dissertations
Neural networks have been widely studied in a number of fields, such as neural architectures, neurobiology, statistics of neural network and pattern classification. In the field of pattern classification, neural network models are applied on numerous applications, for instance, character recognition, speech recognition, and object recognition. Among these, character recognition is commonly used to illustrate the feature and classification characteristics of neural networks.
In this dissertation, the theoretical foundations of artificial neural networks are first reviewed and existing neural models are studied. The Adaptive Resonance Theory (ART) model is improved to achieve more reasonable classification results. Experiments in applying the …
Dichloromethane Pyrolysis And Oxidation : Formation Of Chlorinated Aromatic Precursors To Pcdd/F, Hong-Ming Chiang
Dichloromethane Pyrolysis And Oxidation : Formation Of Chlorinated Aromatic Precursors To Pcdd/F, Hong-Ming Chiang
Dissertations
The pyrolysis and oxidation of dichloromethane is studied in a tubular reactor at 1 atmosphere pressure, residence time between 0.3 to 2.0 seconds and in the temperature range 680 - 840°T. Four reactant concentration ratios are:
I. CH2Cl2 : Ar =1 : 99 II. CH2Cl2 : CH4 : Ar = 1 : 1:98
III.CH2Cl2 : O2 : Ar = 1:4 : 95 IV. CH2Cl2: CH4 : O2 Ar = 1: 4: 94
The degradation of dichloromethane, intermediate product formation and decomposition, and final …
Semi-Strongly Regular Graphs And Generalized Cages, Cong Fan
Semi-Strongly Regular Graphs And Generalized Cages, Cong Fan
Dissertations
Two well-known classes of graphs, strongly regular graphs and cages, have been studied extensively by many researchers for a long period of time. In this dissertation, we mainly deal with semi-strongly regular graphs, a class of graphs including all strongly regular graphs, and (r, g, t)-cages, a generalization of the usual cage concept.
Chapter I introduces the two new concepts: semi-strongly regular graphs and generalized (r, g, t)-cages, gives necessary conditions for the existence of semi-strongly regular graphs and some interesting properties regarding common neighbors of pairs of vertices, and shows connections between these two new concepts and the old …
Section I: Thermodynamic Properties Of Hydrocarbon Radicals, Peroxy Hydrocarbon And Peroxy Chlorohydrocarbon Molecules And Radicals Section Ii: Kinetics And Reaction Mechanisms For : (1) Chloroform Pyrolysis And Oxidation (2) Benzene And Toluene Oxidation Under Atmospheric Conditions, Tsan-Horng Lay
Dissertations
Alkyl radicals are important active intermediates in gas phase photochemistry and combustion reaction systems. With the exception of a limited number of the most elementary radicals, accurate thermodynamic properties of alkyl radicals are either not available or only rough estimations exist. An H atom Bond Increment approach is developed and a data base [sic] is derived, for accurately estimating thermodynamic properties (ΔHf°298, S°298 and Cp(T)) for generic classes of hydrocarbon radical species.
Reactions of alkyl radicals with molecular oxygen are one of the major reaction paths for these radicals in atmospheric photochemistry, oxidation of hydrocarbon …
Effect Of Electrolyte Concentration, Temperature And Clay Type On The Diffusional Properties Of Anions In Clay-Modified Electrodes, Jennifer A. Stein
Effect Of Electrolyte Concentration, Temperature And Clay Type On The Diffusional Properties Of Anions In Clay-Modified Electrodes, Jennifer A. Stein
Dissertations
No abstract provided.
X-Ray Crystallographic Studies On Cross-Linked Hemoglobins, Elias J. Fernandez
X-Ray Crystallographic Studies On Cross-Linked Hemoglobins, Elias J. Fernandez
Dissertations
No abstract provided.
High Breakdown Rank-Based Estimates For Linear Models, William H. Chang
High Breakdown Rank-Based Estimates For Linear Models, William H. Chang
Dissertations
No abstract provided.
The Theory And Applications Of Stratified Graphs, Reza Rashidi
The Theory And Applications Of Stratified Graphs, Reza Rashidi
Dissertations
Physical design is one of several stages in the design of a VLSI chip. In this stage, the specifications of an electrical circuit are converted into a geometrical model. Problems concerning the physical design stage can often be studied by means of graphs. The problems encountered here are routing problems and concern placement of vertices, which represent wires, into layers. All this gives rise to a class of graphs whose vertices are partitioned into classes. Such graphs are called stratified graphs. In this dissertation, we formally define stratified graphs, study their properties, and investigate various algorithmic problems related to these …
A Bootstrap Method To Analyze An Intervention Model With Autoregressive Error Terms, Scott D. Mcknight
A Bootstrap Method To Analyze An Intervention Model With Autoregressive Error Terms, Scott D. Mcknight
Dissertations
The analysis of a particular time-series intervention model involving lag one autoregressive (AR(1)) error terms is the focus of this dissertation. The method of ordinary least squares, and several two stage procedures that are commonly used to analyze this intervention model are examined. The two stage Cochrane-Orcutte, Durbin, and generalized least squares procedures each requires estimation of the AR(1) parameter in stage one before hypothesis testing about the intervention parameters can be performed in stage two. Using Monte Carlo experiments we show that the AR(1) estimates commonly used in these procedures are poor and consequently the stage two hypothesis tests …
An Office Document Retrieval System With The Capability Of Processing Incomplete And Vague Queries, Qianhong Liu
An Office Document Retrieval System With The Capability Of Processing Incomplete And Vague Queries, Qianhong Liu
Dissertations
TEXPROS (TEXt PROcessing System) is an intelligent document processing system. The system is a combination of filing and retrieval systems, which supports storing, classifying, categorizing, retrieving and reproducing documents, as well as extracting, browsing, retrieving and synthesizing information from a variety of documents. This dissertation presents a retrieval system for TEXPROS, which is capable of processing incomplete or vague queries and providing semantically meaningful responses to the users. The design of the retrieval system is highly integrated with various mechanisms for achieving these goals. First, a system catalog including a thesaurus is used to store the knowledge about the database. …
Hydrogeology And Hydrogeochemistry Of Government Marsh, North St. Joseph County, Michigan, Michael C. Kasenow
Hydrogeology And Hydrogeochemistry Of Government Marsh, North St. Joseph County, Michigan, Michael C. Kasenow
Dissertations
A hydrogeologic and hydrogeochemical investigation was conducted at Government Marsh located in St. Joseph County, Michigan from May, 1988, to November, 1993. Information on glacial geology, topography, drainage patterns, hydraulic conductivity, vegetation, water chemistry, and static water table elevations has been collected and analyzed. Data were collected in order to determine directions of ground water flow and areas of recharge and discharge. Bail-down tests, grain-size analysis, and permeameters were used to determine hydraulic conductivity adjacent to and within the wetland. Water table elevations and chemistry were analyzed from wells adjacent to the wetland perimeter and within the boundaries of the …
Isospectral Graphs And The Expander Coefficient, Ian Campbell Walters Jr.
Isospectral Graphs And The Expander Coefficient, Ian Campbell Walters Jr.
Dissertations
The expander coefficient of a graph is a parameter that is utilized to quantify the rate at which information is spread throughout a graph. The eigenvalues of the Lapladan of a graph provide a bound for the expander coefficient of the graph. In this dissertation, we construct many pairs of isospectral graphs with different expander coefficients.
In Chapter I, we define the problem and present some preliminary definitions. We then introduce two constructions that are related to graph composition and that may be employed to produce cospectral and isospectral graphs.
In Chapter II, we investigate the connectivity of and distance …
Comparisons Of Several Medians In A Lognormal K-Sample Context Where Some Data May Be Left-Censored, Stavros Costa Pouloukas
Comparisons Of Several Medians In A Lognormal K-Sample Context Where Some Data May Be Left-Censored, Stavros Costa Pouloukas
Dissertations
No abstract provided.
Synthesis Of Malathion, Malaoxon, And Isomalathion Enantiomers And Examination Of Their Interactions With Acetylcholinesterase, Clifford E. Berkman
Synthesis Of Malathion, Malaoxon, And Isomalathion Enantiomers And Examination Of Their Interactions With Acetylcholinesterase, Clifford E. Berkman
Dissertations
No abstract provided.
Structural Characterization Of Recombinant Polypeptides Of &-Spectrin, Yirong Xu
Structural Characterization Of Recombinant Polypeptides Of &-Spectrin, Yirong Xu
Dissertations
No abstract provided.
Chiral Isoparathion Methyl As A Stereospecific Probe Of Phosphorothiolate Mechanism Of Action; Novel Synthetic Approaches Toward Isoquinolone Alkaloids: Pancratistatin Study, Seungmin Ryu
Dissertations
No abstract provided.
A Spectroscopic Study Of Nitrogen, Nitrogen/Helium And Fluorobenzenes In A Corona Supersonic Discharge, Jing-Chen Luo
A Spectroscopic Study Of Nitrogen, Nitrogen/Helium And Fluorobenzenes In A Corona Supersonic Discharge, Jing-Chen Luo
Dissertations
No abstract provided.
Lithium Binding To Human Rbc Membranes And Substrates Of Second Messenger Systems, Qinfen Rong
Lithium Binding To Human Rbc Membranes And Substrates Of Second Messenger Systems, Qinfen Rong
Dissertations
No abstract provided.
An Investigation Into Clay Intrinsic Properties, Surface Modifications And Applications, G Robert Goss
An Investigation Into Clay Intrinsic Properties, Surface Modifications And Applications, G Robert Goss
Dissertations
No abstract provided.
Segmental Motions Of Oxidized Human Erythrocyte Spectrin-Actin: A Spin Label Epr Study, Benito O. Kalaw
Segmental Motions Of Oxidized Human Erythrocyte Spectrin-Actin: A Spin Label Epr Study, Benito O. Kalaw
Dissertations
No abstract provided.
Synthesis Of Enantioenriched Piperidine-Based, Spirocyclic Analogues Of Af64a And Acetylcholine, Nam Huh
Synthesis Of Enantioenriched Piperidine-Based, Spirocyclic Analogues Of Af64a And Acetylcholine, Nam Huh
Dissertations
No abstract provided.
Development And Functional Properties Of Intramolecular Crosslinked Hemoglobin, Qunyang Zhang
Development And Functional Properties Of Intramolecular Crosslinked Hemoglobin, Qunyang Zhang
Dissertations
No abstract provided.
Symbol Sense And Its Development In Two Computer Algebra System Environments, Brian A. Keller
Symbol Sense And Its Development In Two Computer Algebra System Environments, Brian A. Keller
Dissertations
The purposes of this study were to: (a) explicate the nature of symbol sense, (b) determine the differential effects of two computer algebra system (CAS) environments on students' development of symbol sense, (c) explore differences in symbol sense among students using a CAS and students not using a CAS, and (d) examine students' achievement in calculus with and without the use of a CAS.
Six sections of first-semester calculus at Western Michigan University during the 1992-93 academic year were used in the study. The investigator taught two CAS sections both semesters (n = 41, 34 Fall and n = 35, …
Management Of Dairy Farm Wastewater – A Case Study, Saed Mohamed Al Awadi
Management Of Dairy Farm Wastewater – A Case Study, Saed Mohamed Al Awadi
Dissertations
There are several dairy farms and milk processing plants in U.A.E. which contribute to the problem of industrial wastewater discharges in the country. This study emphasized the waste management aspects of dairy farms and examined the wastewater characteristics, wastewater treatment and effluent reuse in Al-Rawabi Dairy Plant in Dubai as a case study.
An extensive sampling and analysis program was conducted over a period of one year to determine wastewater characteristics at Al-Rawabi Dairy Plant. It has been found that the wastewater COD, BOD, Solids, Nitrogen and Phosphorus content is relatively high but daily variations in pollution loads were not …
Methodology For Modeling High Performance Distributed And Parallel Systems, Rakesh Kushwaha
Methodology For Modeling High Performance Distributed And Parallel Systems, Rakesh Kushwaha
Dissertations
Performance modeling of distributed and parallel systems is of considerable importance to the high performance computing community. To achieve high performance, proper task or process assignment and data or file allocation among processing sites is essential. This dissertation describes an elegant approach to model distributed and parallel systems, which combines the optimal static solutions for data allocation with dynamic policies for task assignment. A performance-efficient system model is developed using analytical tools and techniques.
The system model is accomplished in three steps. First, the basic client-server model which allows only data transfer is evaluated. A prediction and evaluation method is …
A Comprehensive Part Model And Graphical Schema Representation For Object-Oriented Databases, Michael H. Halper
A Comprehensive Part Model And Graphical Schema Representation For Object-Oriented Databases, Michael H. Halper
Dissertations
Part-whole modeling plays an important role in the development of database schemata in data-intensive application domains such as manufacturing, design, computer graphics. text document processing, and so on. Object-oriented databases (OODBs) have been targeted for use in such areas. Thus, it is essential that OODBs incorporate a part relationship as one of their modeling primitives. In this dissertation, we present a comprehensive OODB part model which expands the boundaries of OODB part-whole modeling along three fronts. First, it identifies and codifies new semantics for the OODB part relationship. Second, it provides two novel realizations for part relationships and their associated …
Morphological Operations In Image Processing And Analysis, Chamim Christopher Pu
Morphological Operations In Image Processing And Analysis, Chamim Christopher Pu
Dissertations
Morphological operations applied in image processing and analysis are becoming increasingly important in today's technology. Morphological operations which are based on set theory, can extract object features by suitable shape (structuring elements). Morphological filters are combinations of morphological operations that transform an image into a quantitative description of its geometrical structure which based on structuring elements. Important applications of morphological operations are shape description, shape recognition, nonlinear filtering, industrial parts inspection, and medical image processing.
In this dissertation, basic morphological operations are reviewed, algorithms and theorems are presented for solving problems in distance transformation, skeletonization, recognition, and nonlinear filtering. A …
Medium Access Control Mechanisms For High Speed Metropolitan Area Networks, Michail Papamichail
Medium Access Control Mechanisms For High Speed Metropolitan Area Networks, Michail Papamichail
Dissertations
In this dissertation novel Medium Access Control mechanisms for High Speed Metropolitan Area networks are proposed and their performance is investigated under the presence of single and multiple priority classes of traffic. The proposed mechanisms are based on the Distributed Queue Dual Bus network, which has been adopted by the IEEE standardization committee as the 802.6 standard for Metropolitan Area Networks, and address most of its performance limitations. First, the Rotating Slot Generator scheme is introduced which uses the looped bus architecture that has been proposed for the 802.6 network. According to this scheme the responsibility for generating slots moves …