Engineering Commons^™

Performance Evaluation Of Existing Analytical Methods To Compute The Shear Contribution Provided By Externally Bonded Frp Sheets In Concrete Structures, Rocio Patricia Tumialan

Masters Theses

"External application of FRP composites has been adopted for strengthening and/or repair of concrete structures in many applications during the last two decades. However, the research into shear strengthening using FRP composites has not been widely conducted as compared to flexural strengthening and axial load capacity increase, and the results obtained thus far are scarce and sometimes controversial. This study presents a review of analytical studies and design guidelines on shear strengthening of concrete structures with externally-bonded FRP laminates, and their assessment with experimental data collected from the literature. The strengths and weaknesses of each model and design guidelines/codes/specifications are …

Properties Of Alkaline-Resistant Calcium-Iron-Phosphate Glasses, Jiawanjun Shi

Masters Theses

"The physical properties and alkaline corrosion resistant properties of calcium-iron-phosphate glasses were studied. The addition of Fe₂O₃ decreases the thermal expansion coefficient and increases the glass fiber's Young's modulus in comparison with the addition of CaO. Bulk glass dissolution behavior in alkaline Lawrence solution was studied by weight loss experiments, Raman spectroscopy, and analytical scanning electron microscopy. The corrosion of glass powder in NaOH solution was studied by X-ray diffraction, infrared spectroscopy and high pressure liquid chromatography. The results show that the dissolution rate decreases when the phosphate chain length decreases. Calcium oxide can improve the glass durability in high …

Robust Mechanism Synthesis With Random And Interval Variables, Pavan Kumar Venigella

Masters Theses

"Robust mechanism synthesis ensures that the performance of a mechanism is not sensitive to uncertainties in the mechanism and its environment. The uncertainties include the dimension variations, installation errors, random input motion, and various external forces. Robust mechanism synthesis is used to minimize the impact of these uncertainties on the mechanism performance. Robust mechanism synthesis has been performed by either a probabilistic approach or a worst case approach. The former approach describes uncertain parameters as random variables while the latter approach treats uncertain parameters as interval variables. In this work, methods are developed for robustness assessment and robust mechanism synthesis …

Advanced Controller Design Using Neural Networks For Nonlinear Dynamic Systems With Application To Micro/Nano Robotics, Qinmin Yang

Doctoral Dissertations

"The dissertation focuses on neural network (NN) control designs for nonlinear systems with application to micro/nano robotic. Critical problems in nano scale including thermal drift are also addressed"--Abstract, page iv.

Development Of A Geographic Information System-Based Virtual Geotechnical Database And Assessment Of Liquefaction Potential For The St. Louis Metropolitan Area, Jae-Won Chung

Doctoral Dissertations

"The St. Louis Metropolitan area is the focus the U.S. Geological Survey's Earthquake Hazard Program's plan for assessing and reducing the likely risks of an earthquake likely emanating from New Madrid Seismic Zone (NMSZ), which is the most active seismic zone in the Midwestern United States. The St. Louis Metropolitan area consists of three counties in Missouri and four in Illinois, which are divided by the state boundary along the Mississippi River. Both of the state's respective geological surveys have produced their own geologic maps and datasets, employing dissimilar geodata information and systems, with differing map units, map scales, and …

Architecting System Of Systems: Artificial Life Analysis Of Financial Market Behavior, Nil Hande Ergin

Doctoral Dissertations

"This research study focuses on developing a framework that can be utilized by system architects to understand the emergent behavior of system architectures. The objective is to design a framework that is modular and flexible in providing different ways of modeling sub-systems of System of Systems. At the same time, the framework should capture the adaptive behavior of the system since evolution is one of the key characteristics of System of Systems. Another objective is to design the framework so that humans can be incorporated into the analysis. The framework should help system architects understand the behavior as well as …

Nonlinear Optimization Approach For Upfc Power Flow Control And Voltage Security: Sufficient System Constraints For Optimality, Radha P. Kalyani

Doctoral Dissertations

"This dissertation provides a nonlinear optimization algorithm for the long term control of Unified Power Flow Controller (UPFC) to remove overloads and voltage violations by optimized control of power flows and voltages in the power network. It provides a control strategy for finding the long term control settings of one or more UPFCs by considering all the possible settings and all the (N-1) topologies of a power network. Also, a simple evolutionary algorithm (EA) has been proposed for the placement of more than one UPFC in large power systems"--Abstract, page iv.

Design For Test Techniques For Asynchronous Ncl Designs And Fpgas, Sindhu Kakarla

Masters Theses

"Testing of an electronic chip is an important step in the design process, as it can detect faults and ensure reliability. Design for Test (DFT) methods are used to modify existing designs to enable their testing by Automatic Test Pattern Generators. This thesis focuses on developing testing techniques for design automation of NULL Conventional Logic (NCL) circuits and for detection of capacitive crosstalk effects in Field Programmable Gate Arrays (FPGAs).

A novel technique is developed for testing asynchronous NCL designs aimed at good fault coverage with acceptable gate overhead. The technique focuses on testing stuck-at-faults in the internal feedback paths …

Integrated Product And Its Extended Enterprise Network Design Using Lean Principles, Abhijit K. Choudhury

Masters Theses

"Recently, many system integration companies have begun to intensely focus on suppliers' involvement in the product realization process to enhance their competitiveness. The product architecture has a huge impact on the efficiency of the integrator's supplier network. One of the ways to enhance efficiency is to implement the lean principles while creating a collaborative design/manufacturing/supply chain environment. In this study, two distinct stages of the product realization process, namely, design stage and production stage are considered for determining the design and production supplier networks"--Abstract, page iv.

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.

Microfluidic Biosensors For Intelligent Metabolite Monitoring, Nitin Radhakrishnan

Masters Theses

"Baseline (zero-value) drift and sensitivity degradation are two common problems related with biosensors. In order to overcome these problems, there is a great need for integrating an on-demand, in situ self-diagnosis and self-calibration unit along with the sensor. Utilizing the microfluidic technology, it is possible to explore the feasibility of implementing this function without any externally coupled bulky apparatus. A microsystem including a microfluidic channel and calibration electrodes are prepared by microfabrication techniques"--Abstract, page iv.

Performance Improvements Of Automobile Communication Protocols In Electromagnetic Interference Environments, Fei Ren

Masters Theses

"Electromagnetic Interference (EMI) is frequently encountered in automobile communication systems due to a large number of inductive nodes used in these systems. This thesis investigates the effects of EMI on two types of automobile communication systems, the Controller Area Network (CAN) and the FlexRay. It also proposes a modified Automatic Repeat reQuest (ARQ) scheme to improve the communication performances in EMI environments"--Abstract, page iii.

Identification Of Radial Streaming And Pseudopods In Dermoscopy Images, Sayali Prabhakar Deshpande

Masters Theses

"This thesis demonstrates an algorithm to identify the features of radial streaming and pseudopods found in dermoscopy images of malignant melanoma. The algorithm includes preprocessing images using the Principal Component Transform and an application of mathematical techniques to extract the desired features from the lesion image on the basis of color, size, shape, and orientation with respect to the lesion boundary. These identified features are further used to classify the lesion as malignant or benign. The proposed algorithm has produced a diagnostic accuracy of 90.50% for the training set of 31 malignant and 109 benign images and a diagnostic accuracy …

Executable System Architecting Using Systems Modeling Language In Conjunction With Colored Petri Nets - A Demonstration Using The Geoss Network Centric System, Renzhong Wang

Masters Theses

"Models and simulation furnish abstractions to manage complexities allowing engineers to visualize the proposed system and to analyze and validate system behavior before constructing it. Unified Modeling Language (UML) and its systems engineering extension, Systems Modeling Language (SysML), provide a rich set of diagrams for systems specification. However, the lack of executable semantics of such notations limits the capability of analyzing and verifying defined specifications. This research has developed an executable system architecting framework based on SysML-CPN transformation, which introduces dynamic model analysis into SysML modeling by mapping SysML notations to Colored Petri Net (CPN), a graphical language for system …

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 …

Converting Some Global Optimization Problems To Mixed Integer Linear Problems Using Piecewise Linear Approximations, Manish Kumar

Masters Theses

"Some global optimization problems are converted to mixed-integer linear problems (MILP) using piecewise-linear approximations in this thesis so that they can be solved using commercial MILP solvers, such as CPLEX. Special attention is given to approximating two-term log-sum functions, which appears frequently in generalized geometric programming problems. Numerical results indicate the proposed approach is sound and efficient"--Abstract, page iii.

Neural Network Control Of Nonstrict Feedback And Nonaffine Nonlinear Discrete-Time Systems With Application To Engine Control, Jonathan B. Vance

Doctoral Dissertations

"In this dissertation, neural networks (NN) approximate unknown nonlinear functions in the system equations, unknown control inputs, and cost functions for two different classes of nonlinear discrete-time systems. Employing NN in closed-loop feedback systems requires that weight update algorithms be stable...Controllers are developed and applied to a nonlinear, discrete-time system of equations for a spark ignition engine model to reduce the cyclic dispersion of heat release"--Abstract, page iv.

A Computational Theory For The Generation Of Solutions During Early Conceptual Design, Cari R. Bryant

Doctoral Dissertations

"Advancement in technology is usually made by building on previous experiences and learning from past successes and failures. However, knowledge transfer in the broad field of product design is often difficult to accomplish. Research has shown that successful component configurations, observed from existing products, can be dissected and stored for reuse; but few computational tools exist to assist designers during the conceptual phase of design. Many well-known manual methods (e.g. brainstorming, intrinsic and extrinsic searches, and morphological analysis) rely heavily on individual bias and experience and are often time intensive, laborious tasks that may not catch solutions that are functionally …

Nonlinear Control Of Nonholonomic Mobile Robot Formations, Travis Alan Dierks

Masters Theses

"In this thesis, the framework developed to control a single nonholonomic mobile robot is expanded to include the control of formations of multiple nonholonomic mobile robots. A combined kinematic/torque control law is developed for leader-follower based formation control using backstepping in order to accommodate the dynamics of the robots and the formation in contrast with kinematic-based formation controllers typically found in literature"--Abstract, page iv.

Bridge Damage Detection Using An Intelligent Engineering System, Dionysios N. Danilatos

Masters Theses

"This thesis concerns the design of an algorithm that is capable to detect structural damage in civil infrastructure bridges. The algorithm, which will be dubbed Damage Diagnostics System throughout the thesis, is the software component of a broader Bridge Health Monitoring System. This broader system integrates software and hardware,such as sensors and data acquisition components...The rationale for the Structural Damage Diagnosis is based on the principle of the structural vibration testing. The Health Monitoring System captures the vibration signals, as the bridge responds to excitation from various sources. The purpose of the Diagnostic System is to extract information from the …

Printed Circuit Board (Pcb) Loss Characterization Up-To 20 Ghz And Modeling, Analysis And Validation, Abhilash Rajagopal

Masters Theses

"Dielectric properties and losses are increasingly more important in signal link path characterization, as data rates increases. High-frequency effects such as dielectric losses, dispersion and skin-effect losses need to be considered. For ensuring signal integrity, it is important to characterize losses of printed circuit board (PCB) dielectrics. To extract dielectric properties of a stripline transmission medium, an analytical technique was used...Two test materials were studied, and the extraction procedure was refined. This technique was applied to microstrip transmission lines. Two analytical solutions were derived for extracting practical material parameters. A microstrip test vehicle was designed and the two extraction methods …

Application Of Hybrid Arq To Controller Area Networks, Krishna Chaitanya Emani

Masters Theses

"This thesis proposes two types of Hybrid Automatic Repeat reQuest (HARQ) schemes for the Controller Area Network (CAN) to combat Electro-Magnetic Interference (EMI) and improve network efficiency. The proposed HARQ schemes encode the original CAN data frames by a Reed-Solomon (R-S) code so that burst errors due to EMI may be corrected at the receive nodes. Therefore, the probability of error frames is reduced, thereby reducing the probability of retransmission. Hence, the network efficiency of the system is improved"--Abstract, page iii.

Computational Study Of Flow Over Elliptic Airfoils For Rotor/Wing Unmanned Aerial Vehicle Applications, Timothy William Assel

Masters Theses

"The purpose of this study will be to conduct a parametric investigation on the performance of elliptic airfoils for Rotor/Wing Unmanned Aerial Vehicles. The objective of this study is to conduct a two-dimensional, aerodynamic analysis on a various elliptic airfoil parameters, compare the reults of the analysis with theoretical predictions and experimental results, and evaluate handling and performance characteristics of Rotor/Wing UAVs during hover, transition, and forward flight"--Abstract, page iii.

Innovative Solutions In Bridge Construction, Rehabilitation, And Structural Health Monitoring, Fabio Matta

Doctoral Dissertations

"This dissertation includes three technical papers that investigate the development of innovative technologies for bridge construction, rehabilitation, and structural health monitoring, respectively, at different stages of the technology transfer process...The research impact is twofold: first is the introduction of promising innovative technologies in development and implementation projects with the direct involvement of forward-thinking industry partners; second is the demonstration of the validity of these technologies on the basis of a rigorous scientific approach"--Abstract, page iv.

Enzymatic Synthesis And Characterization Of Oligopeptides, Co-Oligopeptides And Hydroxy Acid Capped Polypeptides In Mixed Aqueous Organic Media, Santhana Srinivasan

Doctoral Dissertations

"Proteolytic enzymes have been used for the synthesis of homo-oligomers and hydroxy acid capped peptides with amino acids and hydroxy acid esters as substrates in aqueous and aqueous organic biphasic and triphasic systems. However, successful incorporation of hydroxy acids in oligopeptide substrates has not been demonstrated. Use of monophasic media comprising of acetonitrile/water in which oligopeptide substrates were soluble was examined for the synthesis of oligomers of neutral and polar amino acids like Met, Tyr, Lys, Gly, Asp and Glu and tailored co-oligomers of Lys-Met and Arg-Met. Effect of reaction parameters such as starting substrate concentration, system composition, reaction time, …

New Techniques To Improve Power Quality And Evaluate Stability In Modern All-Electric Naval Ship Power Systems, Peng Xiao

Doctoral Dissertations

"This dissertation focuses on two crucial issues in the design and analysis of the power electronic systems on modern all-electric naval ships, i.e., power quality control and stability evaluation. It includes three papers that deal with active power filter topology, active rectifier control, and impedance measurement techniques, respectively. To mitigate harmonic currents generated by high-power high-voltage shipboard loads such as propulsion motor drives, the first paper proposes a novel seven-level shunt active power filter topology, which utilizes tapped reactors for parallel operations of switching devices. The multi-level system has been implemented in both regular digital simulation and real-time digital simulator …

Modeling And Control Of Freeze-Form Extrusion Fabrication, Xiyue Zhao

Masters Theses

"Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing technique that extrudes ceramic loaded aqueous pastes layer by layer below the paste freezing temperature for component fabrication. As the FEF is aimed at being conducted at low environmental temperatures, down to -20°C, it is necessary to investigate the effect of environmental temperature on the process. The advantages of fabrication at low temperature have been proved by experiments. Comparisons in terms of operation parameters, self-sustaining ability, and system dynamic response were performed at different environmental temperatures ranging from 20°C to -20°C.

It is commonly known in paste extrusion processes that due to …

Bga Footprints Modeling And Physics Based Via Models Validation For Power And Signal Integrity Applications, Giuseppe Selli

Doctoral Dissertations

"Modeling and simulating the multi-scale nature of a power distribution network (PDN) is essential to ensure the correct functioning of the devices connected to it. Simple parallel-plate sections constitute the core of these PDN geometries, together with sections where a large number of holes and vias are present, as in the case of a BGA footprint. Employing a divide-and-conquer approach allows for the modeling of these geometries separately, i.e., 3-D full wave solvers for the sections with holes and vias, and a cavity model approach, for the simple parallel-plate structures. Also, equivalent circuit models can be obtained for time-domain and …

Analysis Of The Holistic Impact Of The Hydrogen Economy On The Coal Industry, Shannon Perry Lusk

Doctoral Dissertations

"As gas prices soar and energy demand continues to grow amidst increasingly stringent environmental regulations and an assortment of global pressures, implementing alternative energy sources while considering their linked economic, environmental and societal impacts becomes a more pressing matter. The Hydrogen Economy has been proposed as an answer to meeting the increasing energy demand for electric power generation and transportation in an environmentally benign way. Based on current hydrogen technology development, the most practical feedstock to fuel the Hydrogen Economy may prove to be coal via hydrogen production at FutureGen plants. The planned growth of the currently conceived Hydrogen Economy …

The Development And Application Of A Systematic Approach To Evaluating An Academic Department's Brand Meaning, Cassandra C. Elrod

Doctoral Dissertations

"Research of existing literature indicates that below the university level, there has been little effort made in branding academia, namely academic departments. The lack of branding may significantly affect the perceptions that potential students and future employers of these students have about one of these academic units. The impact may be most significant for units where the fields of study that are represented by the department may be unclear, such as in the case of engineering management. However, even in the cases of better-understood fields of study, for example, electrical engineering, the competition for students with other fields of study …