Digital Commons Network^™

An Exploratory Study Of The Videoblogger's Community, John Warmbrodt

Masters Theses

"Videoblogs (vlogs) have emerged as a new form of virtual community. The goal of this study was to explore and understand the videoblogger community by studying the community's structure and the motivations of vloggers"--Abstract, page iii.

On-Line Inspection And Thermal Properties Comparison For Laser Deposition Process, Yu Yang

Masters Theses

"This thesis is focused on comparing the laser deposition cladding with intended design model and comparing the effect of laser deposition process on thermal properties with traditional welding process. It is research on two aspects of laser deposition cladding. The first part of the thesis is aimed at solving the geometric inspection of laser deposition cladding, and the second part is for comparing the thermal properties of laser deposition cladding to samples of conventional welding process"--Introduction, page 1.

Optimal Formation Of Supplier Networks For Product Design And Production Phases To Realize An Evolving Product Family, Padmavathi K. Pakala

Masters Theses

"Due to rapid changes in customer requirements and vast improvements in technology, many product development companies have identified strategies like time-to-market (TTM) compression and product family development as critical for attaining success in today's hyper-competitive markets. Compressing the TTM, to a large extent, is dependent on the suppliers and the project execution skills of the integrator companies. This study presents a methodology for selecting suppliers for two significant phases of the product realization process, namely, product design and production. The proposed methodology uses a two-stage approach for supplier selection where suppliers for product design are selected in the first stage …

The Importance And Influence Of Groundwater Fluctuations In Phytoremediation, Jeff A. Weishaar

Masters Theses

"The primary purpose of this research is to study the relationship between microbial degradation and plant uptake of volatile hydrocarbons, such as benzene, toluene, ethylbenzene and xylene. While these compounds are known to biodegrade and are capable of transport into plant tissue, any relationship between the two removal mechanisms remains largely unknown. The goal of this work is to better understand the interactions of these multiple biological processes within a phtytoremediation effort"--Introduction, page 3.

Configuration, Manufacture, Assembly, And Integration Of A University Microsatellite, Lori Ann Ziegler

Masters Theses

"The Space Systems Engineering Team at the University of Missouri-Rolla (UMR), in conjunction with a number of Air Force, NASA, and industry mentors, is working toward the design, development, and launch of its first satellite, UMR SAT (University of Missouri-Rolla Satellite). This thesis documents the design of the UMR SAT satellites, specifically focusing attention on the layout of all components, component boxes designed for containment and protection from electromagnetic interference and the attachment of components inside the boxes and the boxes to the structure. This thesis also discusses the development of UMR SAT with challenges faced in manufacturing and prototyping …

Development, Modeling, And Simulation Of A Nano Aerial Vehicle Using Empirical Data, Wyatt Emery Davenport

Masters Theses

"The ultimate goals of this study were to use experimental data to estimate the flight capabilities of a flapping wing nano aerial vehicle (NAV), estimate the power required to provide such flight, and develop a controller approach for future use in the design of this aircraft. The experimental data is a collection of measurements of the normal force on a flapping wing taken in stationary water, and was used to develop empirical coefficient derivatives for use in the dynamic modeling of the NAV"--Abstract, page iii.

Energy Efficient Processor Operation And Vibration Based Energy Harvesting Schemes For Wireless Sensor Nodes, Phani Kumar Gajjala

Masters Theses

"A wireless Sensor Network (WSN) is a network of spatially distributed autonomous sensors deployed in the environment in order to cooperatively monitor physical or environmental conditions such as temperature, sound, pressure, motion or pollutants at different locations. Each node in a sensor network is equipped with a radio transceiver, a microprocessor and an energy source such as a battery which should be replaced periodically. To increase the lifetime of the network keeping the small size in mind, methods should be put in place to reduce the power consumption of the sensor node or increase the node life and/or to supply …

E-Design Tools For Friction Stir Welding: Cost Estimation Tool, Pradeep Kumar Tipaji

Masters Theses

"A cost model is an important tool for product design and material selection. An efficient and effective cost estimation tool is necessary for early design evaluation. In this paper, cost estimation models that estimate the production cost for Metal Inert Gas (MIG), Friction Stir (FS), and Friction Stir Spot (FSS) welded joints are presented. These models determine the cost incurred to fabricate each joint along with a detailed explanation of each cost component. Each cost component has been closely analyzed and major cost components have been included in the cost model"--Abstract, page iv.

A Quantitative Study Of Gene Identification Techniques Based On Evolutionary Rationales, Cyriac Kandoth

Masters Theses

"Current gene identification (GI) techniques typically rely on matching biological or chemical properties of specific genes, specific species, specific ecotypes, etc...In this thesis, a new automated GI technique is proposed, and compared against another computer-based technique proposed earlier. Both methods utilize EST data available from NCBI databases to discover previously unknown genes. The newly proposed method identifies one gene family at a time and is based on a distinctive negative selection pattern (NSP) of differences, which is seen between the coding regions of gene family members. The other technique, called ESTminer, attempts genome-wide gene family identification for any organism, by …

A Network Infrastructure For Real-Time Monitoring Of Campus Energy Consumption, Sandeep Kunchum

Masters Theses

"Pressing environmental concerns and rising energy costs have led many organizations to carefully review their energy consumption. Conservation requires that energy use be monitored accurately and continuously, to identify areas with higher energy consumption. Lighting has repeatedly been identified as such an area. A simple, yet effective method for reducing lighting energy consumption is retrofitting existing light fixtures with modern energy-efficient versions. The University of Missouri-Rolla is currently carrying out a lighting retrofit of all fixtures on campus. The pilot building for this project is McNutt Hall, as it has the single highest consumption of lighting energy. The results of …

Cognitive Biases In Risk Management, William Thomas Siefert

Masters Theses

"This thesis contends that most Risk Management/Mitigation programs fail to be as effective as they could be due to a number of mostly overlooked drivers, such as motivation and cognitive biases. The issue of cognitive biases is very seldom addressed. When questioned, most engineers purport to not have any biases. They insist that they use only logic, reasoning, and math to make decisions. A set of data was collected and reviewed for this thesis. The data presented shows that cognitive biases do affect the risk management/mitigation process. Knowledge of these biases and their potential impact on a project will lead …

An Open Framework For Highly Concurrent Hardware-In-The-Loop Simulation, Ryan C. Underwood

Masters Theses

"Hardware-in-the-loop (HIL) simulation is becoming a significant tool in prototyping complex, highly available systems. The HIL approach allows an engineer to build a physical system incrementally by enabling real components of the system to seamlessly interface with simulated components. It also permits testing of hardware prototypes of components that would be extremely costly to test in the deployed environment. Key issues are the ability to wrap the systems of equations (such as Partial Differential Equations) describing the deployed environment into real-time software models, provide low synchronization overhead between the hardware and software, and reduce reliance on proprietary platforms. This thesis …

A Software Defined Radio For Research Into Cognitive Radio, Jason Michael Pratt

Masters Theses

Software defined radios are capable of transmitting and receiving signals over a broad range of frequencies, and can alter their carrier frequency, modulation scheme, and power level by changing the software controlling the radio. Because of these capabilities, a software defined radio is the necessary platform for research into cognitive radio. The aim of cognitive radio is to more fully utilize the RF spectrum by allowing wireless communication systems to scan the spectrum for unused frequency bands and dynamically establish communication over one of those unused bands. This thesis gives a brief introduction into cognitive radio, and currently existing software …

The Influence Of Printed Circuit Board Design On Tem Cell Measurements, Vijay Kasturi

Masters Theses

"The IEC 61967-2 integrated circuit radiated emissions test standard describes the use of the TEM cell to measure near-field emissions from an IC. This test requires a printed circuit board (PCB) to mount to IC. The IEC guidelines allow for flexibility in the design of this test PCB which may cause variations in the measured emissions. This thesis studies the impact of typical variations in the PCB design on the measured emissions"--Abstract, page iii.

Magnetohydrodynamic Power Generation In A Scramjet Using A Post Combustor Generator, Nathan Lee Mundis

Masters Theses

"A scramjet with a post combustor MHD generator is examined. A quasi-one-dimensional model is developed to calculate the flow path from tip to tail. The model includes losses due to combustion irreversibility, incomplete combustion, chemically reacting flow, friction, MHD losses, and nozzle plume modeling. Flight Mach number, magnetic field strength, gas conductivity, MHD load factor, and MHD generator expansion angle are all varied in order to assess their effects on MHD power generated and thrust lost in the engine. The trends produced through the above variations are summarized in a set of model-fit equations. It is concluded that a post …

Cfd Simulation Of Contact Planarization, Shanti Vusirikala

Masters Theses

"Semiconductor devices form the essential components of most electronic devices. The fabrication of circuit elements to manufacture these devices is done by a process known as photolithography, using photoresist layer deposition, optical masks, and etching. As feature sizes become smaller, higher optical precision is required, necessitating an optically flat surface on the photoresist layer. The surface of the photoresist layer can become uneven because of conformation to the topography of the layers underneath or a change in shape of the layer after evaporation of solvent. To combat this, Brewer Science, Inc. has developed a contact planarization process (CON-TACT®) in which …

Device Signal Detection Methods And Time Frequency Analysis, Narayana Ravirala

Masters Theses

"In this thesis the application of independent component analysis (ICA) to a multiple-source detection problem is studied. Specifically, a detection problem that is somewhat of a blend of the classical "signals with unknown parameters in noise" and "random signals in noise" problems is investigated. The idea is to detect the presence of a class of devices from their unintended radio frequency (RF) radiation. Because the signal is not an intended radiation, each device will emit a slightly different pattern. Moreover, these patterns may change under varying conditions such as battery voltage and ambient temperature. In addition, there may be several …

Management Of An Intelligent Argumentation Network For A Web-Based Collaborative Engineering Design Environment, Man Zheng

Masters Theses

"Conflict resolution is one of the most challenging tasks in collaborative engineering design. In the previous research, a web-based intelligent collaborative system was developed to address this challenge based on intelligent computational argumentation. However, two important issues were not resolved in that system: priority of participants and self-conflicting arguments. In this thesis, two methods are developed for incorporating priorities of participants into the computational argumentation network: 1) weighted summation and 2) re-assessment of strengths of arguments based on priority of owners of the argument using fuzzy logic inference. In addition, a method for detection of self-conflicting arguments was developed"--Abstract, page …

Friction Stir Processing Of Cast Magnesium Alloys, Timothy A. Freeney

Masters Theses

"This thesis investigates the feasibility and benefits of using friction stir processing as a thermo-mechanical microstructural modification tool for local property enhancement or casting repair of magnesium alloys, specifically high strength EV31A and WE43"--Abstract, page iv.

Toward Improving Performance Measurement In Public Sector Organizations, Matthew Thomas Kutz

Masters Theses

"The objective of this research is to investigate various means of improving the performance measurement methods for public sector organizations. A case study is conducted using data from the Missouri Department of Transportation (MoDOT). As a government organization, MoDOT must publish measurements of its performance for the general public and for the legislators who provide funding. Currently, MoDOT produces a quarterly publication, called the Tracker, for performance measurement reporting. This research hypothesizes that the Tracker is not an effective performance measurement system and stakeholders of MoDOT would benefit from a more concise and pointed report of MoDOT performance. A software …

Manufacturing And Characterization Of Soy-Based Pultruded Polyurethane Composites, Rama Bhadra Raju Vuppalapati

Masters Theses

"In the recent past, composites have been finding various applications in civil infrastructure, marine, transportation, automotive and non-automotive applications by replacing metals in structural components. Pultrusion is considered to be a cost effective method for manufacturing composite materials.

Polyurethane resin systems form a good alternative to the conventional styrene based systems in pultrusion due to their better physical, chemical and mechanical properties. Polyols derived from soybean oil along with isocyanates produce polyurethanes that can match in many aspects with one derived from the petrochemical polyols. Even though, polyurethanes have good properties there are lots of challenges like designing unique material …

Damping Controllers For Power System Oscillations Using A Static Var Compensator, Sandhya R. Jetti

Masters Theses

"Damping of power system plays an important role in not only increasing the transmission capacity but also in stabilizing the power system, especially after critical faults. Static Var Compensator (SVC) is a shunt FACTS device which has capability of fast and continuous capacitive and inductive reactive power supply to the power system. SVCs are widely used for voltage stability but studies show that they are also effective in providing damping to the system. In this thesis, three types of SVC damping controllers are designed. The first damping controller is an optimal linear controller in which the parameters of a damping …

Manufacturing Of High Performance Composites Using Vacuum Assisted Resin Transfer Molding, V. G. K. Menta

Masters Theses

"The objective of this research is to establish and enhance the existing Vacuum Assisted Resin Transfer Molding (VARTM) process to manufacture high performance composite parts usable in the aerospace industry.

Flat, hat, pi and multi stiffened panels have been manufactured by the VARTM process using AS4-5HS and AS4-8HS carbon fabric, and SI-ZG-5A low viscosity epoxy resin. Silicone-based reusable molds have been designed and developed to manufacture stiffened panels. Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) experiments of the SI-ZG-5A resin system were conducted to determine the storage modulus, loss modulus, and the glass transition temperature. The density and …

Experimental Investigation Of Temperature And Tool Wear In High Speed End-Milling Of Titanium Alloy, Benjamin Nwakile Oguejiofor

Masters Theses

"This thesis presents the results of experimental investigation of temperature and tool wear in high speed end-milling of titanium alloy. The investigation of cutting parameters on temperature in high speed end-milling of thin-walled titanium structure was conducted on Cincinnati Milacron Sabre 750 Vertical Machining Center using a 1/2 Fractional Factorial Design of Experiment with 3 factors at 2 levels each. Data logging of temperature data was carried out using VI logger software. Tool tip temperature at the comers and center of the pocket was estimated. All the factors investigated were found to have a significant effect on workpiece temperature. Radial …

A Light-Weight Middleware Framework For Fault-Tolerant And Secure Distributed Applications, Ian Jacob Baird

Masters Theses

"This thesis outlines the design, implementation, and performance of a lightweight middleware framework for interprocess communication with an update log propagation algorithm. The system was designed and implemented using a point-to-point based lightweight middleware framework and compared to a similar system implemented utilizing CORBA--Abstract, page iii.

Physical Analysis Of Human Hair, Lea Marie Dankers

Masters Theses

"Physical analysis of human hair has been performed to determine the effects of chemical treatments on hair samples. Five samples including an untreated sample were analyzed using various methods. The methods included differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and carbon-13 cross polarization/magic-angle spinning nuclear magnetic resonance (¹³C CP/MAS NMR)"--Abstract, page iii.

Low-Thrust Control Of A Lunar Orbiter, Nathan Harl

Masters Theses

"This thesis presents a method for maintaining a long-term lunar Sun-synchronous orbit using continuous low-thrust hardware. The control method is developed using optimal control theory, which involves controlling a system through the minimization of a desired cost function"--Abstract, page iii.

Operation Of A Brushless Dc Drive For Application In Hybrid Electric Vehicles, James Scott Jenkins

Masters Theses

"One of the goals of a hybrid electric vehicle design is to improve the overall performance of the vehicle by incorporating several different power sources in such a way as to maximize the energy usage. By combining the desirable characteristics of each of the components in the system, the vehicle becomes more efficient to operate. Energy storage systems such as batteries and ultra-capacitors can be used to supply or store energy from the system when needed. The primary power source in this model will be an internal combustion engine coupled with a permanent magnet synchronous generator. The purpose of this …

Distribution System Operation And Planning In The Presence Of Distributed Generation Technology, Gavin Wesley Jones

Masters Theses

"Distributed generation (DG) is becoming an increasingly attractive power generation paradigm in the field of power engineering as economic and environmental factors drive new technologies to be more efficient and less polluting than their earlier counterparts. Although the concept of DG is not new, little research has been done on the topic and even fewer field tests have been performed. This lack of research, along with other factors, has somewhat slowed the acceptance of DG into markets, other than industrial or commercial co-generation for heat and power. This thesis attempts to examine and compare three types of DG: diesel generators, …

Real-Time Detection Of Grip Length Deviation For Fastening Operations: A Mahalanobis-Taguchi System (Mts) Based Approach, Deepak Mohan

Masters Theses

"Hand-held fastening tools are extensively used in manufacturing, especially in aerospace industry. Typically, the process is monitored by the operator and joints are visually inspected after the process is completed. When complex products, such as an aircraft, are considered, fastening process and its inspection can be very time consuming. In addition, no inspection data is typically collected during the process unless a major problem is encountered. Real-time monitoring and verification of the fastening process of joint quality are two important advancements to reduce the manufacturing lead time while ensuring safety and quality"--Abstract, page iv.