Digital Commons Network^™

Automation Of Cad Model Based Assembly Simulations Using Motion Capture, Anup Madhav Vader

Masters Theses

"The manufacturing industry often uses text and video as a supplement for worker training procedures. Unfortunately, text is often difficult to follow and video lends itself to occlusion issues. CAD based animations of assembly operations can overcome these shortcomings while offering greater potential for operations analysis and simulation flexibility. However, creating such CAD based training simulations manually is a time intensive task and many a times fail to reveal the practical assembly issues faced in the real world. Thus, it is highly beneficial to be able to automate these simulations using motion capture from a physical environment. This thesis research …

Development Of Novel Backscatter Communication Systems Using A Multi-Hop Framework And Distributed Beamforming, Vikram Reddy Surendra

Masters Theses

"The goal of this thesis it to develop a wireless networking framework for battery-free devices based on passive, backscatter communication. In contrast to traditional, active communication systems, where the radio signal has to be generated using large amount of energy from batteries, the passive systems reflect the RF signal. The information is encoded by modulating the reflected signal, which consumes significantly less energy than active transmission. The existing passive, backscatter systems have limited communication capabilities. For example, the Radio Frequency Identification (RFID) systems support short-distance, direct communication between active reader and passive tags. The communication range is limited due to …

Design And Critical Performance Evaluation Of Horizontal Axis Hydrokinetic Turbines, Suchi Subhra Mukherji

Masters Theses

"The current work discusses the hydrodynamic performance of horizontal axis hydrokinetic turbines (HAHkT) under different turbine geometries and flow conditions. Hydrokinetic turbines are a class of zero-head hydropower systems which utilize kinetic energy of flowing water to drive a generator. However, such turbines often suffer from low-efficiency. A detailed computational fluid dynamics study was performed using a low-order k-[omega] SST (Shear Stress Transport) turbulence model to examine the effect of each of tip-speed ratio, solidity, angle of attack and number of blades on the performance of small HAHkTs with a power capacity of 10 kW. The numerical models (both two-dimensional …

The Effectiveness Of The Natural Resource Conservation Service (Nrcs) And Huff Rainfall Distribution Methods For Use In Detention Basin Design, Todd Wayne Dablemont

Masters Theses

"This thesis focuses on the effectiveness of the NRCS and Huff rainfall distribution methods for use in detention basin design. This study required the use of HEC-HMS, hydrologic modeling software, in order to analyze the distribution methods. Three separate detention basins and their watersheds were modeled for this study. The watersheds were analyzed for both undeveloped and developed conditions. The parameters analyzed include detention basin inflow, detention basin outflow, watershed peak discharge, and detention basin storage capacity. The determination of detention basin effectiveness was based upon these parameters. The NRCS distribution method is widely used; however, many who use it …

Integration And Test Of A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, Ryan Alan Pahl

Masters Theses

"Due to the launch safety constraints placed on university-built small satellites, designing a low-cost propulsion system to meet mission requirements presents a significant challenge to aspiring student engineers. The Missouri University of Science and Technology is currently developing a low-cost, two-phase propulsion system using the refrigerant R-134a as the propellant that can be stored at low pressures while still providing sufficient performance to meet mission goals. The purpose of this study is to present the testing results of a refrigerant-based cold gas system utilizing R-134a as a saturated liquid propellant and the ability to design this system to be portable …

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 …

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 …

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 …

Control And Applications Of Double Input Dc-Dc Power Electronic Converters, Venkata Anand Kishore Prabhala

Masters Theses

"Multi-input power electronic converters (MIPEC) are increasingly gaining interest in the fields of renewable energy systems and hybrid electric vehicles (HEV). The main advantage of MIPECs is their ability to interface several energy sources and storage devices using a single power conversion stage. Therefore, they provide simpler control and smaller parts count. In this thesis, various aspects of the utilization of double-input (DI) converters in solar and HEV applications are explored. For instance, a DI buckboost topology is proposed for a photovoltaic (PV)/battery energy system. The converter is controlled in a way that maximum power is drawn from the PV …

Implementing Frequency Regulation Capability In A Solar Photovoltaic Power Plant, Venkata Ajay Kumar Pappu

Masters Theses

"Photovoltaic power plants pose some challenges when integrated with the power grid. Today's PV plants focus on extracting the maximum power from the arrays. This makes the PV system unavailable for helping in regulating the grid frequency as compared to conventional synchronous generators. A new technique for tracking a pseudo-maximum power point for creating power reserve is presented. This will help provide fast response in injecting power to respond to rapid load changes in a manner analogous to the inertia of a rotating machine. This helps in contributing toward frequency regulation. This thesis examines the implementation of a two stage …

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 …

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, …

Simulation Of Pem Fuel Cells: Validation Of Model And Incorporation Of Humidity Dynamics, Steven Francis Rodgers

Masters Theses

"Fuel cell technologies have been receiving increased attention by industry and researchers due to growing societal and inevitable economic pressures to find an alternative for fossil fuels. At the forefront of this is the demand for fuel cell models: models to elucidate fundamental physical phenomena underlying fuel cell function and models that are not computationally demanding yet reasonably accurate to allow designers to incorporate fuel cells into consumer products. One of the latter type has recently been developed based on a software package that is already in widespread use in the automotive industry for the simulation of mechanical, thermal, electrical, …

Signal Analysis For Multiple Target Materials Through Wavelet Transforms, Rajat Pashine

Masters Theses

"Signal identification based on different sensing systems like microwaves, infra-red, x-rays and terahertz waves is one of the classic problems in signal processing. Earlier methods had relied mainly on the amplitude spectrum obtained by these sensing techniques mainly due to non-availability of the phase information for the signals. Most of them are based on techniques like absorbance spectrum that requires a reference material's signal for the test material's identification. They are also sensitive to noise and highly dependent on the peak detection algorithms. Modern equipments with both amplitude and phase information provide an opportunity for time-domain signal based methods that …

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 …

Evaluation Of Metal Detection Audio Alert Signals Of An/Pss-14 By Means Of Real Time Visualization, Sandesh Srikantaiah Chandrashekar

Masters Theses

"The sweep arm of the AN/PSS-14 Landmine Detector attached to an independent visualization device will transform the AN/PSS-14 into a hand-held data acquisition system for conversion of real time MD and GPR audio alert signals into captured visual trace displays on an on-board PDA computer screen so that momentary sounds of millisecond durations can be captured and displayed for visual scrutiny and interpretation by analytical on-board data processing procedures. This is a part of a two-man team that is developing a visual data adapter for the AN/PSS-14 Landmine Detector where the current thesis is concentrating only on MD audio alerts. …

Standoff Raman Spectroscopy Detection Of Trace Explosives, Abhijeet Singh

Masters Theses

"During the 2003-present Iraq war, Improvised Explosive Devices (IEDs) are being used extensively by the terrorists against the coalition forces and these IEDs were responsible for 40% of coalition force casualties, by the end of 2007. As these IEDs are not based on standard production formulae, their tracking and detection becomes extremely complicated. Laser Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy are among the many techniques that have shown promise in detection of explosive compounds. However, the performance of these systems is dependent on the concentration of explosives and ambient noise.

The research presented in this thesis applies signal processing …

A Real-Time Visualization Of An/Pss-14 Audio Alert Signals For Land Mine Detection Validation, Nitin Kolekar

Masters Theses

"The central idea of the current research is visualization of audio alerts from AN/PSS-14. A visualization device connected to the arm of PSS-14 will show real-time display of MD and GPR Audio Alert signals from PSS-14. This visualization device displays both amplitude-time and spectral frequency-time formats of the signals. The latter format achieves visual separation of combined, simultaneous, MD and GPR alerts. The joint occurrence of MD and GPR signals in a specific time window confirms the presence of landmine. This window is defined by the time of occurrence of MD peak and time of occurrence GPR diffraction from onset …

Understanding Corrosion Of Ni₃(Si,Nb) Alloys In Hot Sulfuric Acid, Jen-Hsien Hsu

Doctoral Dissertations

"The Sulfur-Iodine thermochemical cycle has been proposed as a method for producing large quantities of hydrogen gas from water. However, the extreme operating environments involved limit the possible materials for construction.

Through proper heat treatment and composition control, the modified patented Ni₃(Si,Nb) alloy keeps high temperature strength to greater than 750⁰C and can be deformed by cold rolling more than 50% using multiple passes and intermediate anneals. The corrosion resistance is reproducible and maintains less than 5 mpy for a broad range of boiling sulfuric acid concentrations, including 70 wt%.

In the boiling 70 wt% sulfuric acid corrosion tests, kinetic …

Thermodynamic Based Modeling For Nonlinear Control Of Combustion Phasing In Hcci Engines, Joshua Bradley Bettis

Masters Theses

"Low temperature combustion modes, such as Homogeneous Charge Compression Ignition (HCCI), represent a promising means to increase the efficiency and significantly reduce the emissions of internal combustion engines. Implementation and control are difficult, however, due to the lack of an external combustion trigger. This thesis outlines a nonlinear control-oriented model of a single cylinder HCCI engine, which is physically based on a five state thermodynamic cycle. This model is aimed at capturing the behavior of an engine which utilizes fully vaporized gasoline-type fuels, exhaust gas recirculation and intake air heating in order to achieve HCCI operation. The onset of combustion, …

Dynamic Networking For Programmable Logic Controller Communication, Richard Andrew Hardison

Masters Theses

"This thesis confronts the issue of set path communication in Programmable Logic Controllers (PLCs). In order to increase reliability in a networked automated process, it is necessary to develop a dynamic method of communication between PLCs. Three methods for dynamic messaging in PLCs are explored in this work. These methods are based on the real-time reconfiguration of message paths when communication fails on the originally configured path. The simplest method involves replacing the original message block with an Add-On Instruction (AOI) which can accept multiple communication paths and has the ability to switch between these paths to maintain communication. A …

Computational Intelligence Methods In Wireless Sensor Networks, Raghavendra V. Kulkarni

Doctoral Dissertations

"Wireless sensor networks (WSNs) are networks of autonomous nodes that sense, compute and communicate in order to monitor an environment collectively. Ad hoc deployment, dynamic environment and resource constraints in nodes need to be considered while addressing WSN challenges such as deployment, localization, routing and scheduling. Adaptive mechanisms that exhibit intelligent behavior in complex and dynamic environments are desirable to address these challenges. The potential of computational intelligence ( CI) based approaches for addressing WSN challenges is investigated in this study. Contributions of this dissertation are in the following three areas: critical literature analysis, new architectures and approaches, and new …

Explosives Recognition And Awareness Training: A Psychological Approach To Pre-Blast Mitigation, James Wade Hawkins

Masters Theses

"The nation's security strategy tends to be reactionary to a specific event. It is rare when established policies have proven successful, even though there is substantial financial and resource investment. The payoff is measured by analyzing the desired minimal effect rather than prevention of the event altogether. Such is the case in combating explosives-related threats. Today, research and development, science and technology, are plugged as the saviors of a post-blast event. Synthetic and composite materials are used to strengthen barriers and cutting-edge technology is utilized to refine the latest in standoff detection. These legitimate measures provide a sense of security …

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 …

Synthesis And Characterization Of Metal Decorated Bamboo Structured Carbon Nanotubes For Hydrogen Storage, Sean Charles Mickey

Doctoral Dissertations

"Although hydrogen has been considered as a viable alternative fuel, the storage systems used to contain the hydrogen must be improved for large scale use. A variety of conceivable storage options exist ranging from compressed gas, cryogenic liquid, chemical solid state storage, and adsorptive surfaces. Carbon nanotubes (CNTs) provide a potentially viable option for hydrogen storage applications as a high surface area, lightweight media for adsorptive storage, but do not efficiently store hydrogen at ambient temperatures. Metal hydrides, on the other hand, are able to store large weight percents of hydrogen in a chemical solid state, but generally have unfavorable …

Graded-Index Fiber Collimator Enhanced Extrinsic Fabry-Perot Interferometer, Yinan Zhang

Masters Theses

"In this thesis, we studied a fringe visibility enhanced extrinsic Fabry-Perot interferometer (EFPI) by fusion splicing a quarter-pitch graded-index fiber (GIF) fiber to the lead-in single-mode fiber (SMF). The performance of the GIF collimator is theoretically analyzed using a ray matrix model and experimentally verified through beam divergence angle measurements. The fringe visibility of the GIF-collimated EFPI is measured as a function of the cavity length and compared with that of a regular SMF-EFPI. At the cavity length of 500µm, the fringe visibility of the GIF-EFPI is 0.8 while that of the SMF-EFPI is only 0.2. The visibility enhanced GIF-EFPI …

Doubly Fed Induction Generator With Integrated Energy Storage System For Smoothening Of Output Power, Nishant Swaraj Chouhan

Masters Theses

"Wind energy is one of the fastest growing renewable energies in the world today. However, integration of wind power into the power system network is still confronting many challenges. One of the main challenges is the suppression of wind power fluctuations. This thesis focuses on integration of wind power with energy storage to overcome the integration challenges. The first part of this thesis investigates the suitability of energy storage systems for transmission, distribution and wind farm applications. A review on the available energy storage systems is performed considering several criteria. Efforts are made to investigate solutions that meet all the …

Modeling The Practical Performance Of Switched-Capacitor Converters And A Method For Automating State-Space Model Generation, Jordan M. Henry

Masters Theses

"A new modeling technique and a method for automating the modeling process are introduced for analyzing complex switched-capacitor (SC) converters. The model uses conventional circuit analysis methods to derive state-space models of each switching state. Steady-state performance is derived and expressed as an equivalent resistance. Whereas previous techniques have provided either the detailed performance of a simple SC converter or the limiting performance of a complex SC converter, this new model is flexible enough to provide detailed performance for any practical converter. Nonuniform component choices, asymmetric duty cycles, and other deviations from an ideal converter can be readily included. Dynamics …

Residential Energy Monitoring: Missouri S&T Solar Village Development, Christopher David Wright

Masters Theses

"As energy costs are rising, public and private sector groups are searching for improved energy efficiency technology. Research tools for predicting residential energy usage are lagging behind commercial developments. Missouri S&T has a unique and strong opportunity to strengthen its involvement in the development of residential energy research and knowledge. The S&T Solar Village, a collection of homes designed for energy efficiency and renewable energy, is poised to support this research. This thesis develops a design for residential energy evaluation and data collection of the four solar homes in the Village. The energy evaluation system identifies over 300 sensors and …

Low-Thrust Control Of Orbital Elements, Nathan Harl

Doctoral Dissertations

"This dissertation presents a method for controlling the orbital elements of a spacecraft using continuous low-thrust systems. The method involves the use of a general performance index, which is designed to minimize the difference between the instantaneous orbital elements of a spacecraft and some desired set of orbital elements. Due to the generality of the controller design, the resultant controller can be applied to a wide variety of scenarios about various bodies in space. To minimize the designed performance index, a shooting method and a Sequential Quadratic Programming algorithm are utilized and compared.

The primary application of the general controller …