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Articles 631 - 660 of 2077
Full-Text Articles in Physical Sciences and Mathematics
Analysis Of Eurycea Hybrid Zone In Eastern Missouri, Bonnie Jean Beasley
Analysis Of Eurycea Hybrid Zone In Eastern Missouri, Bonnie Jean Beasley
Masters Theses
"Evolutionary mechanisms are often difficult to observe in action because evolution generally works slowly over time. Hybrid zones provide a unique opportunity to observe many evolutionary processes, such as reinforcement, because of the rapid changes that tend to occur in these zones. Salamanders provide an ideal model for examining the rapid changes in populations that result from hybridization because many closely-related species lack reproductive barriers. In Missouri, a well-documented hybridization zone exists among the two subspecies Eurycea longicauda longicauda (long-tailed salamander) and E. L. melanopleura (dark-sided salamander). These salamanders inhabit caves, limestone creek beds, and abandoned mine shafts. A closely …
Dynamic Ant Colony Optimization For Globally Optimizing Consumer Preferences, Pavitra Dhruvanarayana
Dynamic Ant Colony Optimization For Globally Optimizing Consumer Preferences, Pavitra Dhruvanarayana
Masters Theses
"Consumer preference for any product or product feature can be expressed in the form of a utility function. Many such utility functions form a part of a preference map, where each of these are expressed in terms of the attributes defining the product or the product feature. In order to optimize the design, it is required to optimize the overall utility function obtained by a mathematical combination of individual utility functions defined in the preference map. The objective of this research is to devise and implement an algorithm to optimize all the individual utility functions comprised in a preference map …
Population Control In Evolutionary Algorithms, Jason Edward Cook
Population Control In Evolutionary Algorithms, Jason Edward Cook
Masters Theses
"Traditional evolutionary algorithms (EAs) are powerful robust problem solvers that have several fixed parameters which require prior specification. Having to determine good values for any of these parameters can be problematic, as the performance of EAs is generally very sensitive to these parameters, requiring expert knowledge to set optimally without extensive use of trial and error. Parameter control is a promising approach to achieving this automation and has the added potential of increasing EA performance based on both theoretical and empirical evidence that the optimal values of EA strategy parameters change during the course of executing an evolutionary run. While …
Multi Axis Slicing For Rapid Prototyping, Divya Kanakanala
Multi Axis Slicing For Rapid Prototyping, Divya Kanakanala
Masters Theses
"With multi-axis capability, direct laser deposition process can produce a metal part without the usage of support structures. In order to fully utilize such a capability, a slicing method for multi-axis metal deposition process is discussed. Using the geometry information of adjacent layers, the slicing direction and layer thickness can be changed as needed. A hierarchy structure is designed to manage the topological information which is used to determine the slicing sequence. The parallel slicing process is studied to build hollow type structure. With such a character, the hole like feature can be deposited directly to save the required machining …
Inverse Limits With Upper Semi-Continuous Set Valued Bonding Functions: An Example, Christopher David Jacobsen
Inverse Limits With Upper Semi-Continuous Set Valued Bonding Functions: An Example, Christopher David Jacobsen
Masters Theses
"While there is a wealth of information pertaining to inverse limits with single valued bonding maps, comparatively little is known about inverse limits with upper semi-continuous set valued bonding functions. In order to add somewhat to the communal knowledge on the subject, this paper provides an example of an inverse limit with a single upper semi-continuous set valued bonding function. It is then shown that the space is a continuum, and its structure is examined via its arc components and through various of its properties, such as dimension and decomposability"--Abstract, page iii.
Contribution-Based Priority Assessment In A Web-Based Intelligent Argumentation Network For Collaborative Software Development, Maithili Satyavolu
Contribution-Based Priority Assessment In A Web-Based Intelligent Argumentation Network For Collaborative Software Development, Maithili Satyavolu
Masters Theses
"Decision making is an important aspect of the collaborative software development process which usually involves complex process of conflict resolution. Stakeholders approach decision making process from multiple perspectives and their priorities play a vital role in it. The priority assessment methods used in the argumentation process so far are usually static. Priorities remain constant throughout the decision making process. In order to make the collaborative system more closely replicate real-world scenarios, this work incorporates dynamic priority assessment into a web-based collaborative system which is based on intelligent computational argumentation. It evaluates priorities dynamically for each cycle of decision process based …
Water Analysis For Emerging Environmental Contaminants, Xiaoliang Cheng
Water Analysis For Emerging Environmental Contaminants, Xiaoliang Cheng
Masters Theses
"The presence of emerging environmental contaminants in water bodies used either as drinking water or for recreational purpose has received considerable attention in the recent years. The emerging environmental contaminants can be defined as a wide range of chemicals that have been determined in the environment which may present serious health risks for humans. The occurrence of these contaminants indicate that both household and industrial chemicals have been introduced to water resources, a wide variety of chemicals, such as disinfection byproducts, pharmaceutical and personal care products and so on, have been detected at cetiain levels in either water bodies or …
Developing A Model For Evaluating Software Tools In Education, Vedant Jain
Developing A Model For Evaluating Software Tools In Education, Vedant Jain
Masters Theses
"This thesis proposes a research model to evaluate computer-mediated learning technology, user acceptance of the technology, and the effect of the technology on learning outcomes. This thesis also introduces two innovative research techniques for such evaluations, that is, eye-tracking and the think aloud protocol. Think aloud protocol allows us to understand a user's state of mind while he/she is interacting with the system. Eye-tracking provides additional insights into a user's cognitive state while using the system and can help triangulate the results. We demonstrated the application of the research model and research techniques in evaluating visualization software designed in a …
Palynology Of The Middle To Upper Eocene Esmeraldas Formation In The Nuevo Mundo Syncline Area, Middle Magdalena Valley Basin, Colombia, Guillermo Rodriguez-Forero
Palynology Of The Middle To Upper Eocene Esmeraldas Formation In The Nuevo Mundo Syncline Area, Middle Magdalena Valley Basin, Colombia, Guillermo Rodriguez-Forero
Masters Theses
"The palynology of the Eocene Esmeraldas Formation in the Middle Magdalena Valley Basin, Colombia was analyzed in order to constrain the age of the unit. This formation is a very important oil reservoir in the Middle Magdalena Valley Basin, which is a product of a fragmentation of a Cenozoic foreland basin by the Northern Andes. It created structural complexities and syntectonic deposition. The lateral continuity of the formation, as well as its correlations with lithostratigraphic units is adjacent basins, are not clearly understood. The Los Corros Fossil Horizon, a mollusk horizon in the upper part of the Esmeraldas Formation, is …
An Artificial Life Approach To Evolutionary Computation: From Mobile Cellular Algorithms To Artificial Ecosystems, Shivakar Vulli
An Artificial Life Approach To Evolutionary Computation: From Mobile Cellular Algorithms To Artificial Ecosystems, Shivakar Vulli
Masters Theses
"This thesis presents a new class of evolutionary algorithms called mobile cellular evolutionary algorithms (mcEAs). These algorithms are characterized by individuals moving around on a spatial population structure. As a primary objective, this thesis aims to show that by controlling the population density and mobility in mcEAs, it is possible to achieve much better control over the rate of convergence than what is already possible in existing cellular EAs. Using the observations and results from this investigation into selection pressure in mcEAs, a general architecture for developing agent-based evolutionary algorithms called Artificial Ecosystems (AES) is presented. A simple agent-based EA …
Impact Of Management Status, Gender, And Level Of Project Involvement On Corporate Governance In A Role-Based Enterprise Portal Environment, Daniel Augusto Pereira Brás Sequeira
Impact Of Management Status, Gender, And Level Of Project Involvement On Corporate Governance In A Role-Based Enterprise Portal Environment, Daniel Augusto Pereira Brás Sequeira
Masters Theses
"The underlying objective of this research project is to investigate the impact of management status, gender, and level of project involvement on corporate governance in a role-based enterprise portal environment. This is achieved through a case study which included the development of a role-based enterprise portal site prototype assessed through surveys targeted at different stakeholders at the case company. Six hypotheses were formulated addressing the core research question. The outcomes of the hypotheses testing suggest employees' perceptions of role-based enterprise portal's effectiveness, usability, and corporate identity design are, in general, not influenced by the employees' management role, gender, and project …
2-D Path Planning For Direct Laser Deposition Process, Swathi Routhu
2-D Path Planning For Direct Laser Deposition Process, Swathi Routhu
Masters Theses
"The zigzag and offset path have been the two most popular path patterns for tool movement in machining process. Different from the traditional machining processes, the quality of parts produced by the metal deposition process is much more dependent upon the choice of deposition paths. Due to the nature of the metal deposition processes, various tool path patterns not only change the efficiency but also affect the deposition height, a critical quality for metal deposition process. This thesis presents the research conducted on calculating zigzag pattern to improve efficiency by minimizing the idle path. The deposition height is highly dependent …
Closed-Form Solutions To Discrete-Time Portfolio Optimization Problems, Mathias Christian Goggel
Closed-Form Solutions To Discrete-Time Portfolio Optimization Problems, Mathias Christian Goggel
Masters Theses
"In this work, we study some discrete time portfolio optimization problems. After a brief introduction of the corresponding continuous time models, we introduce the discrete time financial market model. The change in asset prices is modeled in contrast to the continuous time market by stochastic difference equations. We provide solutions for these stochastic difference equations. Then we introduce the discrete time risk-measure and the portfolio optimization problems. We provide closed form solutions to the discrete time problems. The main contribution of this thesis are the closed form solutions to the discrete time portfolio models. For simulation purposes the discrete time …
Comparing The Chelating Abilities Of N-Acetylcysteine And N-Acetylcysteine Amide In Vitro For Lead Poisoning Treatment, Weiqing Chen
Comparing The Chelating Abilities Of N-Acetylcysteine And N-Acetylcysteine Amide In Vitro For Lead Poisoning Treatment, Weiqing Chen
Masters Theses
"Lead poisoning is a perennial and serious health problem around the world. The daily widespread use of lead has dramatically increased the degree and longevity of its exposure to humans, exacerbating the task of lead poisoning treatment. Lead exerts adverse effects on cardiovascular, central nervous, renal, gastrointestinal, and reproductive systems. The common treatment for lead poisoning is chelation therapy. Chelators were proposed to treat lead poisoning a very long time ago. However, chelators have severe side effects that could cause more problems, in addition to lead poisoning. Therefore, another group of drugs has been suggested --- antioxidants. This type of …
The Role Of Skeletal Development In Body Size Evolution Of Two North American Frogs, Sarah Beth Havens
The Role Of Skeletal Development In Body Size Evolution Of Two North American Frogs, Sarah Beth Havens
Masters Theses
"In order to better understand the evolution of miniaturization in Acris blanchardi, a North American Hylid with a unique life history and of ecological interest in the United States. The development and ossification sequences of 48 larvae, 5 juveniles and 5 adult A. blanchardi were examined. The adult was described by Maglia et al. (2007) to be a miniature and to display morphological novelties. In addition, 44 larvae, 2 juvenile and 5 adults of Pseudacris crucifer a closely related frog that has been suggested to be a miniature, were examined. The cranial and postcranial adult elements of this species, as …
Zinc Oxide Nanoparticle Disruption Of Store-Operated Calcium Entry In A Muscarinic Receptor Signaling Pathway, Hsiu-Jen Wang
Zinc Oxide Nanoparticle Disruption Of Store-Operated Calcium Entry In A Muscarinic Receptor Signaling Pathway, Hsiu-Jen Wang
Masters Theses
"The influences of ZnO nanoparticles on cellular responses to activation of muscarinic receptors were studied in Chinese hamster ovary cells expressing the human M3 muscarinic acetylcholine receptor. ZnO particles (20 nm) induced cytotoxicity in a time and concentration-dependent manner: following a 24 h exposure, toxicity was minimal at concentrations below 20 µg/ml but virtually complete at concentrations above 28 µg/ml. ZnO particles did not affect antagonist binding to M3 receptors or allosteric ligand effects, but increased agonist binding affinity while eliminating guanine nucleotide sensitivity. At a noncytotoxic concentration (10 µg/ml), ZnO increased resting [Ca²⁺]i from 40 to 130 nM without …
Degradation Of Organic Matter In Water In The Presence Of Catalyst And Uv Radiation, Bimali Bandaranayake
Degradation Of Organic Matter In Water In The Presence Of Catalyst And Uv Radiation, Bimali Bandaranayake
Masters Theses
Organic contaminants specially dyes, presents in water is a major environmental problem. Organic compounds can be degraded completely in the presence of photocatalysts and UV radiation. The kinetics of degradation of three dyes was studied using a variety of UV photocatalytic materials. The dyes (methylene blue, malachite green, chrysodoine R) were chosen based on their polarity differences. Catalysts consisting of pure TiO2, mixed oxides of TiO2 containing SiO2, and others containing SiO2 and iron oxide, SiO2/ ZrO2/ CeO2, and CeO2/SiO2 were studied. The TiO2/ SiO2 and SiO2/ZrO2/CeO2 catalysts exhibited the highest degradation rates for methylene blue. The more hydrophobic pure …
Nanoporous High Surface Area Silicas With Chelating Groups For Heavy Metal Ion Adsorption From Aqueous Solution, Kothalawalage Nuwan Kothalawala
Nanoporous High Surface Area Silicas With Chelating Groups For Heavy Metal Ion Adsorption From Aqueous Solution, Kothalawalage Nuwan Kothalawala
Masters Theses
Nanoporous high surface area silicas are an ideal substrate for the design of materials with useful properties via chemical surface modification. The adsorption of heavy metals for contaminated water detoxification is one potential application. In this work we have used three different kinds of silica substrates with varying pore structures; commercially available narrow pore and wide pore silica gels, as well as surfactant templated mesoporous SBA-15 exhibiting a relatively narrow pore size distribution. These silicas have each been subjected to post-synthesis modification with an organosilane consisting of ethylenediamine triacetic acid functionalities for chelation/adsorption of metal ions from aqueous solution. The …
Ditopic Dithiophosphonates And Their Related Rotaxanes, Robert Ray Baum Jr.
Ditopic Dithiophosphonates And Their Related Rotaxanes, Robert Ray Baum Jr.
Masters Theses
Grafting dithiophosphonate groups onto a naphthalenediimide core yields anionic axles, which in conjunction with the 15DN38C10 crown ether and cationic metallic systems generate neutral bimetallic rotaxanes. The association constant for the rotaxane system was calculated by the single-point method using 1H NMR spectroscopy. Metallic systems reacted with our anionic axles were SnMe3, SnPh3, Cu(PPH3)i, SnMe2, and SnPh2. The structures of several axle-metal complexes and one rotaxane were obtained by X-ray crystallography.
Seismic Interpretation And Reservoir Characterization Of The Middle Frio Formation In The Stratton Field Gulf Coast Basin Of South Texas Using Three-Dimensional Seismic And Well Log Data, Uchenna H. Aboaja
Masters Theses
"The Stratton field is a large mature gas field located between Nueces County and Kleberg County in the northwest Gulf Coast Basin of south Texas. The Oligocene middle Frio Formation is one of the major progradational units within the Stratton field. It is characterized by rapid deposition and high subsidence rates that create complex internal facies architecture. The reservoir facies architecture of the middle Frio Formation is described as channel-fill deposits, crevasses-splay deposits, and floodplain mudstones. Previous two-dimensional seismic studies indicate some level of compartmentalization. Three-dimensional seismic and well log data provided by the Bureau of Economic Geology at the …
Intelligent Computational Argumentation For Evaluating Performance Scores In Multi-Criteria Decision Making, Rubal Wanchoo
Intelligent Computational Argumentation For Evaluating Performance Scores In Multi-Criteria Decision Making, Rubal Wanchoo
Masters Theses
"Multi Criteria Decision Making (MCDM) is a discipline aimed at assisting multiple stakeholders in contemplating a decision paradigm in an uncertain environment. The decision analysis to be performed involves numerous alternative positions assessed under varied criterion. A performance score is assigned for each alternative in terms of every criterion and it represents satisfaction of the criteria by that alternative. In a collaborative decision making environment, performance scores are either obtained when a consensus can be reached among stakeholders on a particular score or in some cases or controversial when stakeholders do not agree with each other about them. In the …
A Pilot Study In An Application Of Text Mining To Learning System Evaluation, Nitsawan Katerattanakul
A Pilot Study In An Application Of Text Mining To Learning System Evaluation, Nitsawan Katerattanakul
Masters Theses
"Text mining concerns discovering and extracting knowledge from unstructured data. It transforms textual data into a usable, intelligible format that facilitates classifying documents, finding explicit relationships or associations between documents, and clustering documents into categories. Given a collection of survey comments evaluating the civil engineering learning system, text mining technique is applied to discover and extract knowledge from the comments. This research focuses on the study of a systematic way to apply a software tool, SAS Enterprise Miner, to the survey data. The purpose is to categorize the comments into different groups in an attempt to identify "major" concerns from …
Cloud Security Requirements Analysis And Security Policy Development Using A High-Order Object-Oriented Modeling Technique, Kenneth Kofi Fletcher
Cloud Security Requirements Analysis And Security Policy Development Using A High-Order Object-Oriented Modeling Technique, Kenneth Kofi Fletcher
Masters Theses
"Security continues to be a major challenge for cloud computing, and it is one that must be addressed if cloud computing is to be fully accepted. Most technological means of securing non-cloud computing systems can be either applied directly or modified to secure a cloud; however, no integrated model-based methodology is yet available to analyze cloud security requirements and develop policy to deal with both internal and external security challenges. This work proposes just such a methodology and demonstrates its application with specific cases. Cloud assets are represented by high order object models, and misuse cases together with malactivity swimlane …
Cretaceous/Paleogene Boundary Biostratigraphy And Palynofacies Of The Alo-1 Well, Southeastern Nigeria, Janet Diane Raymer
Cretaceous/Paleogene Boundary Biostratigraphy And Palynofacies Of The Alo-1 Well, Southeastern Nigeria, Janet Diane Raymer
Masters Theses
"The Cretaceous/Paleogene boundary (K/Pg) has been studied in great detail because of the fascination most people have with the extinction of the dinosaurs. The response of the vegetation to this extinction event has been studied in detail in mid to high latitudes, but little is known about what happened in the tropics. Sixty-seven samples from the Nsukka and Imo formations in the Alo-1 well in the Anambra Basin, southeastern Nigeria have been studied for their palynological contents. The aims of the study was to use spores, pollen and dispersed organic matter components to interpret biostratigraphy, and evaluate depositional conditions across …
Calcium Carbonate Precipitation Mechanisms And Geochemical Analysis Of Particulate Material Found Within The Waters Of Maramec Spring, St. James, Missouri, Kyle Steven Rybacki
Calcium Carbonate Precipitation Mechanisms And Geochemical Analysis Of Particulate Material Found Within The Waters Of Maramec Spring, St. James, Missouri, Kyle Steven Rybacki
Masters Theses
"The purpose of the present study is to determine whether a mineral phase is precipitating from solution in the natural Maramec Spring system giving the spring water a milky blue color, to identify the mineral phase, and to investigate potential mechanisms for inducing precipitation. Maramec Spring is a first-order magnitude spring located 11 km southeast of St. James, Missouri. The water that expels from Maramec Spring varies between being near saturation, but undersaturated in calcium, with respect to calcite (saturation index of 0.994 mg/L). Moving downstream, away from the conduit, the spring waters increase in pH and temperature. Eh is …
Content Based Image Retrieval For Bio-Medical Images, Vikas Nahar
Content Based Image Retrieval For Bio-Medical Images, Vikas Nahar
Masters Theses
"Content Based Image Retrieval System (CBIR) is used to retrieve images similar to the query image. These systems have a wide range of applications in various fields. Medical subject headings, key words, and bibliographic references can be augmented with the images present within the articles to help clinicians to potentially improve the relevance of articles found in the querying process. In this research, image feature analysis and classification techniques are explored to differentiate images found in biomedical articles which have been categorized based on modality and utility. Examples of features examined in this research include: features based on different histograms …
Event Detection From Click-Through Data Via Query Clustering, Prabhu Kumar Angajala
Event Detection From Click-Through Data Via Query Clustering, Prabhu Kumar Angajala
Masters Theses
"The web is an index of real-world events and lot of knowledge can be mined from the web resources and their derivatives. Event detection is one recent research topic triggered from the domain of web data mining with the increasing popularity of search engines. In the visitor-centric approach, the click-through data generated by the web search engines is the start up resource with the intuition: often such data is event-driven. In this thesis, a retrospective algorithm is proposed to detect such real-world events from the click-through data. This approach differs from the existing work as it: (i) considers the click-through …
Representation And Validation Of Domain And Range Restrictions In A Relational Database Driven Ontology Maintenance System, Patrick Garrett. Edgett
Representation And Validation Of Domain And Range Restrictions In A Relational Database Driven Ontology Maintenance System, Patrick Garrett. Edgett
Masters Theses
"An ontology can be used to represent and organize the objects, properties, events, processes, and relations that embody an area of reality [1]. These knowledge bases may be created manually (by individuals or groups), and/or automatically using software tools, such as those developed for information retrieval and data mining. Recently, the National Science Foundation funded a large collaborative development project for the semi-automated construction of an ontology of amphibian anatomy (AmphibAnat [2]). To satisfy the extensive community curation requirements of that project, a generic, Web-based, multi-user, relational database ontology management system (RDBOM [3]) was constructed, based upon a novel theoretical …
Etherannotate: A Transparent Malware Analysis Tool For Integrating Dynamic And Static Examination, Joshua Michael Eads
Etherannotate: A Transparent Malware Analysis Tool For Integrating Dynamic And Static Examination, Joshua Michael Eads
Masters Theses
"Software security researchers commonly reverse engineer and analyze current malicious software (malware) to determine what the latest techniques malicious attackers are utilizing and how to protect computer systems from attack. The most common analysis methods involve examining how the program behaves during execution and interpreting its machine-level instructions. However, modern malicious applications use advanced anti-debugger, anti-virtualization, and code packing techniques to obfuscate the malware's true activities and divert security analysts. Malware analysts currently do not have a simple method for tracing malicious code activity at the instruction-level in a highly undetectable environment. There also lacks a simple method for combining …
Laryngeal Apparatus And Call Structure In North American Hylids, Barbara Ann Catherine Fears
Laryngeal Apparatus And Call Structure In North American Hylids, Barbara Ann Catherine Fears
Masters Theses
"Although the ecological implications and structure of frog calls have been the subject of much study, little is known about the association between the laryngeal apparatus morphology and call structure in North American hylids. In this study linear measurements of the laryngeal apparatus were captured and compared to the call structures of thirteen species of North American hylids. Species examined included: Pseudacris crucifer, P. triseriata, P. ocularis, Acris crepitans blanchardi, Hyla avivoca, H. cinerea, H. gratiosa, H. chrysoscelis, H. versicolor, H. squirella, H. femoralis, H. arenicolor, and H. eximia. Six homologous landmark points were identified, and the lengths between them …