Digital Commons Network^™

Data Aggregation In Wireless Sensor Networks, Priya Kasirajan

Masters Theses

"Energy efficiency is an important metric in resource constrained wireless sensor networks (WSN). Multiple approaches such as duty cycling, energy optimal scheduling, energy aware routing and data aggregation can be availed to reduce energy consumption throughout the network. This thesis addresses the data aggregation during routing since the energy expended in transmitting a single data bit is several orders of magnitude higher than it is required for a single 32 bit computation. Therefore, in the first paper, a novel nonlinear adaptive pulse coded modulation-based compression (NADPCMC) scheme is proposed for data aggregation. A rigorous analytical development of the proposed scheme …

Detection Of Explosive Threats By Using Embedded Wireless Sensor Based Networks, Jake Daniel Hertenstein

Masters Theses

"This thesis focuses on the development of novel schemes for the detection of unintended electromagnetic emissions (UEE) from passive radio frequency (RF) receivers and chemical and biological (CB) agents for the purpose of locating explosive threats (ET) to improve survivability for equipment and personnel in the surrounding environment. The methods and architectures used in this work were developed for use with wireless sensor networks (WSNs). While previous work has shown that highly sensitive equipment is capable of long-range detection of UEE the intention of this work is to develop a network of small, low cost smart sensor nodes (SSNs) capable …

Efficient Modular Arithmetic Units For Low Power Cryptographic Applications, Rajashekhar Reddy Modugu

Masters Theses

"The demand for high security in energy constrained devices such as mobiles and PDAs is growing rapidly. This leads to the need for efficient design of cryptographic algorithms which offer data integrity, authentication, non-repudiation and confidentiality of the encrypted data and communication channels. The public key cryptography is an ideal choice for data integrity, authentication and non-repudiation whereas the private key cryptography ensures the confidentiality of the data transmitted. The latter has an extremely high encryption speed but it has certain limitations which make it unsuitable for use in certain applications. Numerous public key cryptographic algorithms are available in the …

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 …

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 …

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 …

Energy-Efficient Task-Scheduling And Networking Protocols For Secure Wireless Networks, Sandeep Kolli

Masters Theses

"The performance of wireless networks is dependent on a number of factors including the available energy, energy-efficiency, data processing delay, transmission delay, routing decisions, security overhead, etc. Traditionally, due to limited resources, nodes were tasked with only collecting measurements and sending them to a base station or central unit for processing. With increased capabilities of microprocessors the data processing is pushed more toward network and its more capable nodes. This thesis focuses to virtualize the processing resources of the entire network and dynamically distribute processing steps along the routing path while optimizing performance. Additionally, a new multi-key encryption (MKE) scheme …

The Properties And Structure Of Tin Phosphate Glasses Modified With Other Oxides, Jong Wook (Austin) Lim

Masters Theses

"The main objective of this research was to evaluate the properties and structures of glasses from the stannous (SnO) phosphate system for possible use in low temperature optical applications. Glasses in the binary xSnO-(100-x)P₂O₅ system (50 ≤ x ≤ 70) were prepared and their thermal and optical properties were evaluated. Differences in glass transition temperatures (T_g) measured here and reported in the literature were explained by differences in the residual water content in the glasses, as determined by infrared spectroscopy. In general, increasing the SnO content of the binary glasses increased the refractive index and the glass transition …

Characterizing Near-Field Circuit Board Radiation Using Crossed Electric And Magnetic Dipole Sources, Weiping He

Masters Theses

"A method to analyze radiated emissions of electronic components/circuits is presented in this thesis. More specifically the purpose of this approach is to determine an equivalent source model to accurately represent the radiated emissions produced by the circuits and components. The proposed equivalent source model, which is able to predict both electric and magnetic fields at various distances from the device under test, consists of an array of both electric and magnetic dipoles. Each source point includes two electric dipoles orientated in x and y directions and two magnetic dipoles in x and y directions"--Abstract, page iii.

Characterization Of The Neutron Flux Spectrum At The Missouri University Of Science And Technology Research Reactor, Zachary Andrew Kulage

Masters Theses

"A new remotely accessible shielded cell is being constructed at the Missouri University of Science and Technology Research Reactor (MSTR). The heavily shielded cell will be able to receive highly irradiated specimens directly from the reactor and will be equipped with radiation-hardened cameras, remote manipulators and gamma spectroscopy. The cell will allow the manipulation and monitoring of highly activated specimens from both a workstation at the MSTR and at remote locations using a Webbased internet interface. The ability to access and control the shielded cell via a remote internet connection will make it useful to a wide variety of users. …

Microalgal Bioremediation Of Nutrients In Wastewater And Carbon Dioxide In Flue Gas, Anand Murali Narasimhan

Masters Theses

"Microalgae are potential biofuel feedstocks that can provide solutions to the twin challenges of energy security and environmental pollution. They have great potential for the removal of excess nitrogen and phosphorus from wastewater including the farm runoff. They can capture carbon dioxide in the flue gas from coal fired power plants thereby reducing greenhouse gas and also producing algal biomass, which can be converted into biofuel. In this study, the nutrient consumption of Scenedesmus algae was investigated in a batch culture and the biomass yield was determined. Algae were able to utilize carbon in the form of soluble carbonates which …

Energy Expenditure Analysis Of Redesigned Mechanical Assists For Medium Girder Bridge, Karthik Kumar

Masters Theses

"U.S. Army bridge crew soldiers perform tough manual material handling (MMH) tasks during the assembly of a Medium Girder Bridge (MGB). The bridge parts are very heavy and are manually lifted from pallets, carried to the construction site and assembled with other bridge parts. An energy expenditure study on the soldiers handling the bridge parts revealed that the energy expenditure rate of the soldiers exceeds the NIOSH prescribed safety limit of 3.5 Kcal/min. This leads to high risk of musculoskeletal disorders. The study deals with modifying the first redesign of mechanical assists for medium girder bridge (MGB) and studying the …

A Comparative Study Of Capacitor Voltage Balancing Techniques For Flying Capacitor Multi-Level Power Electronic Converters, Vennela Yadhati

Masters Theses

"With the advent of multilevel converters for high power applications in industry, a need to develop simpler topologies and control techniques has arisen. The flying capacitor multilevel inverter (FCMLI) is one such topology which is gaining popularity in recent years with many advantages such as extra ride-through capabilities because of the capacitor storage, redundancy in switching states, low common mode voltage ratio, improved power quality, etc. In this thesis, different basic multilevel converter topologies and their advantages and applications are discussed. The thesis mainly focuses on single-phase five-level FCMLI topology. Different control techniques for capacitor voltage regulation like staircase modulation, …

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 …

Improving Resiliency Using Graph Based Evolutionary Algorithms, Jayakanth Jayachandran

Masters Theses

"Resiliency is an important characteristic of any system. It signifies the ability of a system to survive and recover from unprecedented disruptions. Various characteristics exist that indicate the level of resiliency in a system. One of these attributes is the adaptability of the system. This adaptability can be enhanced by redundancy present within the system. In the context of system design, redundancy can be achieved by having a diverse set of good designs for that particular system. Evolutionary algorithms are widely used in creating designs for engineering systems, as they perform well on discontinuous and/or high dimensional problems. One method …

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 …

Application Of Life Cycle Assessment To Estimate Environmental Impacts Of Surface Coal Mining, Ofentse Ditsele

Masters Theses

"Coal plays an important role in meeting the energy needs of the World. Given its abundance and low cost, its use is bound to increase with the growing energy demand. Despite its importance, there are concerns over coal's environmental burdens. In order to extract and use coal in a sustainable manner, sustainability assessment has to be comprehensive. Life Cycle Assessment (LCA) provides systematic and quantifiable measures for assessing environmental burdens of products and processes. Extensive LCA work has been done on coal use, particularly in electricity generation, but, the coal mining stage has been neglected, for the most part. This …

Finite Element Analysis And Fatigue Test On The Bicuspids To Support Theory Of Abfraction, Madhuchandra Mahadevaswamy

Masters Theses

"Abfraction is a small crack or notch found at the cervical areas of a teeth due to the loss of enamel tissues in the teeth. Proposed explanations for are that it is caused by toothbrush abrasion, acid erosion, and the mechanical forces applied on the teeth due to chewing, biting, tongue activity. There is disagreement among dentists as to the primary causes of abfraction. Some dentists believe that abfraction is caused by toothbrush abrasion and erosion due to acidic food and drinks. Other dentists believe that tensile and compressive forces acting on the teeth from non-axial, cyclical loading over an …

The Lived Experience: Pulmonary Arterial Hypertension And Intravenous Prostaglandin Therapy, Phyllis D. Boone

Masters Theses

A descriptive phenomenological study was proposed to obtain a subjective description of the experience of living with intravenous prostaglandin treatment for pulmonary arterial hypertension. It was intended to determine what kinds of elements are common to the experience with study participants, to develop an aggregate structure of the experience from the individual descriptions of it, and add to what is now known about this phenomenon. It was anticipated that the stories told by the participants could help to determine how nurses can assist future patients to live optimally within the confines of a palliative treatment for this incurable illness.

Unfortunately, …

Microalgae Harvesting By Flocculation With Polymer-Coated Magnetite Particles, Humayun Shariff

Masters Theses

"Although microalgae are considered to be one of the potentially significant feedstock for renewable biofuels, harvesting them efficiently from culture ponds has been a major hurdle. The conventional harvesting methods such as centrifugation and filtration are very time and labor intensive processes. Gravimetrical settlement with the aid of cationic flocculants is the most widely employed technique, but suffers from the difficulty in recovering microalgae floes. Furthermore, recycling of these flocculants after the harvesting process is not possible. Polymer-coated magnetite particles have been investigated for applications in various fields. This research has focused on the development of a novel and efficient …

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 …

The Capacity Of Diatom Species To Survive Ingestion By The Algivorous Minnow, Pimephales Notatus, Paul Gregory Grubach

Masters Theses

The capacity of diatom species to survive gastrointestinal passage through the algivorous minnows Pimephales notatusand Campostoma anomalum was studied. From a site on the Grand River in northeastern Ohio, 27 minnows and 7 epilithic diatom samples were taken. In order to determine whether diatom taxa varied in digestibility, live/dead ratios of diatom cells taken from the minnows’ feces were compared with live/dead ratios of cells taken from immersed rocks. Diatoms that were live/undigested at the time of collection were differentiated from dead/digested cells under light microscopy by noting the presence of chloroplasts and/or lipid droplets. Seventy-seven percent of the …

Student-Consultant Continuum: Incorporating Writing Center Techniques Of Peer Review Into The Composition Classroom, Maria Lynn Soriano

Masters Theses

Peer collaboration about writing often functions as a required step in the writing processes of first-year writing students. Within the composition classroom, students read and respond to the writing of their peers, sometimes obtaining useful feedback, and sometimes just getting “You did a good job” as an evaluation. Outside of the classroom, the Writing Center exists as a space where students can work with a trained consultant to receive helpful suggestions and a thorough evaluation of their writing. Though the first-year writing classroom and the Writing Center exist as physically separate places, both rely on principles of collaboration and conversation …

Maskless Additive Manufacturing Of Micro Structures By Laser Sintering Of Nanoparticles, Vivekram Ramanathan

Masters Theses

"The focus of this study was to investigate an alternate microfabrication process of sintering nanoparticles using a patterned laser light to generate two dimensional (2D) and three dimensional (3D) geometries. With trends of producing electronic and medical devices using cheaper and faster technologies, a new procedure was developed to deposit and bond miniature patterns of silver nanoparticles onto silicon substrates.

The process consists of spraying silver nanoparticles onto the substrate while a patterned or modulated laser beam is focused onto the sprayed nanoparticles. These nanoparticles exposed under the modulated laser light undergo partial melting or sintering and adhere to the …

Decentralized Coordinated Ilc System Design And Transient Growth Control Using Iteration-Varying Filter, Qing Liu

Masters Theses

"In automation control area, with the increasing demand in task complexity and high control precision, coordination between systems is required. There are mainly two types of coordinated systems, decentralized and centralized. This thesis is focused on a large array of coordinated systems, and the decentralized structure is preferred. To achieve high control precision in a coordinated system, many existing approaches may work, and in the system performing the repeating process, Iterative Learning Control (ILC) is a useful approach. Therefore, in this thesis, a decentralized coordinated ILC system is proposed and analyzed. The proposed control system is especially useful in coordinating …

Integration And Characterization Of An Electrical Storage System For A Hydrogen Fuel Cell Plug-In Hybrid Electric Vehicle, Edward Alexei Anculle Arauco

Masters Theses

"Hydrogen fuel cell hybrid vehicles are an advance technology that promises to solve the energy crisis in transportation and green houses emissions. Even more, Plug-in or extended range vehicles can add diversity in energy sources. Extended range vehicles have the capability to extract energy from the grid and hence reduce the cost of operation of the vehicle. EcoCAR: the NeXt Challenge is a Noth [sic] American competition with seventeen schools participating across North America. Missouri S&T is developing a Fuel Cell Plug-in Hybrid electric vehicle which has a large lithium-ion battery able to store 16 kWh. The fuel cell powertrain …

Synergy Between Biology And Systems Resilience, Ashik Chandra

Masters Theses

"Resilient systems have the ability to endure and successfully recover from disturbances by identifying problems and mobilizing the available resources to cope with the disturbance. Resiliency lets a system recover from disruptions, variations, and a degradation of expected working conditions. Biological systems are resilient. Immune systems are highly adaptive and scalable, with the ability to cope with multiple data sources, fuse information together, makes decisions, have multiple interacting agents, operate in a distributed manner over a multiple scales, and have a memory structure to facilitate learning. Ecosystems are resilient since they have the capacity to absorb disturbance and are able …

Analysis Of The Theta-D Filter As Applied To Hit-To-Kill Interceptors And Satellite Orbit Determination, Michael W. Dancer

Masters Theses

"When designing feedback control systems, there is often a need for estimation methods that provide system information that is not readily available via sensors placed within the system. In many cases a sensor that measures a particular system state either does not exist or is prohibitively expensive. In addition, all realistic systems contain some degree of nonlinearity. This thesis focuses on two such cases: missile guidance with bearings-only measurements and GPS satellite orbit determination. In each case, a new nonlinear filter, the [theta]-D method, is used and evaluated for its performance in providing the necessary estimation. To aid the filter …

Internet-Accessible Hot Cell With Gamma Spectroscopy At The Missouri University Of Science And Technology Research Nuclear Reactor, Edwin Grant

Masters Theses

A dual-chambered internet-accessible heavily shielded facility with pneumatic access to the University of Missouri Science and Technology (Missouri S&T) 200 kW Research Nuclear Reactor (MSTR) core has been built and is currently under low level irradiation testing. The facility allows distance users doing collaborative work with Missouri S&T researchers to manipulate and analyze neutron irradiated samples remotely. The system consists of two shielded compartments, one for multiple sample storage (up to 11 samples), and the other for isolated radiation measurements and spectroscopy. The second chamber has multiple detector ports, graded shielding, and has the capability to support gamma spectroscopy using …

Validation Of Driving Simulator And Driver Perception Of Vehicle Mounted Attenuator Markings In Work Zones, Durga Raj Mathur

Masters Theses

"This research work sought to validate the driving simulator at Missouri University of Science and Technology and to evaluate the vehicle mounted attenuator (VMA) markings for various times of day. For comprehensive validation of the driving simulator, a framework is proposed which is demonstrated using a fixed-base driving simulator. Objective and subjective evaluations were conducted, and validation of the driving simulator was performed at specific locations and along the highway. Field data were collected for a partial lane closure using a global positioning system (GPS) along the work zone and supplemented with video recordings of traffic data at specific locations …