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Finite Element Simulation Of Indentation Of Porous Materials, Aditi Saran

University of Kentucky Master's Theses

Finite element simulation of indentation is presented in this thesis. A rigid cylindrical indenter of flat end is used in all the cases, in which the simulation focuses on the effect of a hole on the indentation behavior of materials including elastic and elasto-plastic materials. In the simulation, the material is assumed to be a half-space. The relations between load and displacement are determined as a function of the hole size. Also indentation under cyclic loading is simulated for an elastic-perfect plastic half space. The influence of factors causing fatigue deformation like amplitude, median load and frequency is addressed. The …

Optimization Of Blowing And Suction Control On Naca0012 Airfoil Using Genetic Algorithm With Diversity Control, Liang Huang

University of Kentucky Doctoral Dissertations

Active control of the flow over an airfoil is an area of heightened interest in the aerospace community. Previous research on flow control design processes heavily depended on trial and error and the designers knowledge and intuition. Such an approach cannot always meet the growing demands of higher design quality in less time. Successful application of computational fluid dynamics (CFD) to this kind of control problem critically depends on an efficient searching algorithm for design optimization. CFD in conjunction with Genetic Algorithms (GA) potentially offers an efficient and robust optimization method and is a promising solution for current flow control …

Optimization And Simulation Of Just-In-Time Supply Pickup And Delivery Systems, Keng Hoo Chuah

University of Kentucky Doctoral Dissertations

A just-in-time supply pickup and delivery system (JSS) manages the logistic operations between a manufacturing plant and its suppliers by controlling the sequence, timing, and frequency of container pickups and parts deliveries, thereby coordinating internal conveyance, external conveyance, and the operation of cross-docking facilities. The system is important to just-in-time production lines that maintain small inventories. This research studies the logistics, supply chain, and production control of JSS. First, a new meta-heuristics approach (taboo search) is developed to solve a general frequency routing (GFR) problem that has been formulated in this dissertation with five types of constraints: flow, space, load, …

Observed Nonlinear Responses In Patterned Superconducting, Ferromagnetic, And Interacting Thin Films, Daniel Byron Watkins

University of Kentucky Doctoral Dissertations

Many advances in technology ranging from biology and medicine through engineering and computer science to fundamental physics and chemistry depend upon the capability to control the fabrication of materials and devices at the submicron scale. Quantum mechanical effects become increasingly important to atomic and molecular interactions as the distances between neighbors decrease. These effects will provide materials and device designers with additional flexibility to establish properties of the designers choice, but the cost of this additional flexibility must be paid in the complexity of nonlinearities entering the interactions and the design process. The work presented here has provided several early …

Neuromechanical Control Of Locomotion In Intact And Incomplete Spinal Cord Injured Rats, Anil Kumar Thota

University of Kentucky Master's Theses

Rodent models are being extensively used to investigate the effects of traumatic injuryand to develop and assess the mechanisms of repair and regeneration. We presentquantitative assessment of 2D kinematics of overground walking and for the first time3D joint angle kinematics of all four limbs during treadmill walking in the intact and inincomplete spinal cord contusion injured (iSCI) adult female Long Evans rats. Phaserelationship between joint angles on a cycle-by-cycle basis and interlimb footfalls areassessed using a simple technique. Electromyogram (EMG) data from major flexor andextensor muscles for each of the hindlimb joints and elbow extensor muscles of theforelimbs synchronized to …

Development And Assessment Of An Inspection Technique For Coating Evaluation, Mangesh Suresh Kolharkar

University of Kentucky Master's Theses

The US Navy spends around $75 million on maintenance and rework of corroded structures, especially in the ballast tanks of ships. The Navy will profit immensely with better surface coating and quality at source with real time inspection system. The approach taken to improve the coating is the use of optically active paint system. This kind of paint will fluoresce with an incident UV light. The fluorescence or glow can be used to detect holidays or defects on the surface. The inspection prototype developed uses a high end camera and intense UV light source. The paint and additive properties are …

Probabilistic Databases And Their Applications, Wenzhong Zhao

University of Kentucky Doctoral Dissertations

Probabilistic reasoning in databases has been an active area of research during the last twodecades. However, the previously proposed database approaches, including the probabilistic relationalapproach and the probabilistic object approach, are not good fits for storing and managingdiverse probability distributions along with their auxiliary information.The work in this dissertation extends significantly the initial semistructured probabilistic databaseframework proposed by Dekhtyar, Goldsmith and Hawkes in [20]. We extend the formal SemistructuredProbabilistic Object (SPO) data model of [20]. Accordingly, we also extend the SemistructuredProbabilistic Algebra (SP-algebra), the query algebra proposed for the SPO model.Based on the extended framework, we have designed and implemented …

Robust Generic Model Control For Parameter Interval Systems, Joseph Michael Istre

University of Kentucky Doctoral Dissertations

A multivariable control technique is proposed for a type of nonlinear system with parameter intervals. The control is based upon the feedback linearization scheme called Generic Model Control, and alters the control calculation by utilizing parameter intervals, employing an adaptive step, averaging control predictions, and applying an interval problem solution. The proposed approach is applied in controlling both a linear and a nonlinear arc welding system as well in other simulations of scalar and multivariable systems.

Domestic And External Debt: The Doomed Quest For Equal Treatment, Anna Gelpern, Brad Setser

Georgetown Law Faculty Publications and Other Works

Until recently, governments borrowed from domestic residents and foreign investors using very different instruments. Residents bought "domestic debt" - paper denominated in local currency and governed by domestic law. Foreign investors preferred "external debt", which offered foreign currency and foreign law. Because there was virtually no overlap between resident and nonresident holdings, it mattered little that lawyers and economists defined domestic and external debt differently: lawyers focused on features such as governing law and jurisdiction, economists on the holder's residence and currency of denomination. The legal and economic definitions of domestic and external debt were effectively bundled: "domestic debt" meant …

Lessons From A Story Untold: Nike V. Kasky Reconsidered, David C. Vladeck

Georgetown Law Faculty Publications and Other Works

The Supreme Court's recent dismissal, apparently on jurisdictional grounds, of the writ of certiorari it had granted to review Nike, Inc. v. Kasky has brought into sharp focus a number of critiques of the commercial speech doctrine - some new, some longstanding. At issue in Nike were communications Nike made to customers, newspaper editors, college presidents and athletic directors, and others responding to allegations that Nike had engaged in, or was complicit in, the mistreatment of foreign workers. Respondent Marc Kasky contended that Nike's communications contained significant misstatements of fact and thus were actionable under California's unfair competition and false …

Development And Evaluation Of A Controller Area Network Based Autonomous Vehicle, Matthew John Darr

University of Kentucky Master's Theses

Through the work of researchers and the development of commercially availableproducts, automated guidance has become a viable option for agricultural producers.Some of the limitations of commercially available technologies are that they onlyautomate one function of the agricultural vehicle and that the systems are proprietary toa single machine model.The objective of this project was to evaluate a controller area network (CAN bus)as the basis of an automated guidance system. The prototype system utilized severalmicrocontroller-driven nodes to act as control points along a system wide CAN bus.Messages were transferred to the steering, transmission, and hitch control nodes from atask computer. The task …

Pokerface: Emotion Based Game-Play Techniques For Computer Poker Players, Lucas Cockerham

University of Kentucky Master's Theses

Numerous algorithms/methods exist for creating computer poker players. This thesis comparesand contrasts them. A set of poker agents for the system PokerFace are then introduced. A surveyof the problem of facial expression recognition is included in the hopes it may be used to build abetter computer poker player.

Bidirectional Lao* Algorithm (A Faster Approach To Solve Goal-Directed Mdps), Venkata Deepti Kiran Bhuma

University of Kentucky Master's Theses

Uncertainty is a feature of many AI applications. While there are polynomial-time algorithms for planning in stochastic systems, planning is still slow, in part because most algorithms plan for all eventualities. Algorithms such as LAO* are able to find good or optimal policies more quickly when the starting state of the system is known.

In this thesis we present an extension to LAO*, called BLAO*. BLAO* is an extension of the LAO* algorithm to a bidirectional search. We show that BLAO* finds optimal or ^_E-optimal solutions for goal-directed MDPs without necessarily evaluating the entire state space. BLAO* …

Fault Links: Identifying Module And Fault Types And Their Relationship, Inies Raphael Chemmannoor Michael

University of Kentucky Master's Theses

The presented research resulted in a generic component taxonomy, a generic code-faulttaxonomy, and an approach to tailoring the generic taxonomies into domain-specific aswell as project-specific taxonomies. Also, a means to identify fault links was developed.Fault links represent relationships between the types of code-faults and the types ofcomponents being developed or modified. For example, a fault link has been found toexist between Controller modules (that forms a backbone for any software via. itsdecision making characteristics) and Control/Logic faults (such as unreachable code).The existence of such fault links can be used to guide code reviews, walkthroughs, testingof new code development, as well …

High Resolution Geophysical Investigation Of Late Quaternary Deformation In The Lower Wabash Valley Fault System, Frederick Alexander Rutledge Iii

University of Kentucky Master's Theses

Seven and a half kilometers of high-resolution SH-wave seismic reflection profiles were collected across the Mt. Vernon graben, a 35 km by 3 km graben (bounded by the Wabash Island (WIF) and Hovey Lake faults (HLF)) in the southern Wabash Valley fault system (WVFS) of southern Indiana. Forty-six discrete faults were imaged that displaced Quaternary horizons in the vicinity of the WIF and HLF. The structural styles associated with faults include: 1) normal displacement, 2) reverse displacement and other compressional features, 3) varying magnitudes of slip along fault planes, and 4) different senses of slip along individual fault planes. Carbon …

Optimization Of Drill Design And Coolant Systems During Dental Implant Surgery, Varahalaraju Kalidindi

University of Kentucky Master's Theses

Dental implants are an effective alternative for the replacement of missing teeth. The success of the implant depends on how well a bone heals around the implant, a process known as osseointegration. However, excessive heat generated during the bone drilling will cause cell death and may prevent osseointegration of the implant, resulting in early failure. There are many factors which contribute to the heat generation during drilling. Experiments were carried out to investigate the affect of variable drilling factors on heat generation during drilling operation. Natural bone is not an ideal material for such research, as it varies widely in …

Tolerance Allocation For Kinematic Systems, Mathieu Barraja

University of Kentucky Master's Theses

A method for allocating tolerances to exactly constrained assemblies is developed. The procedure is established as an optimization subject to constraints. The objective is to minimize the manufacturing cost of the assembly while respecting an acceptable level of performance. This method is particularly interesting for exactly constrained components that should be mass-produced. This thesis presents the different concepts used to develop the method. It describes exact constraint theory, manufacturing variations, optimization concepts, and the related mathematical tools. Then it explains how to relate these different topics in order to perform a tolerance allocation. The developed method is applied on two …

Validation Of Detached Eddy Simulation Using Lestool For Homogeneous Turbulence, Sai Kumar Doddi

University of Kentucky Master's Theses

Detached Eddy Simulation (DES) is a hybrid turbulence model, a modification to the one-equation model proposed by Spalart and Allmaras (1997) [26]. It combines the advantages of both the RANS and LES models to predict any fluid flow. Presently, the focus is on using Homogeneous Turbulence to test the DES model. In an attempt to scrutinize this model, many cases are considered involving the variance of DES grid spacing parameter, CDES, the grid density, Reynolds number and cases with different initial conditions. Choosing Homogeneous Turbulence for our study alienates complications related to the geometry, boundary conditions and other flow characteristics …

Scale Model Experiments And Numerical Study On A Steel Teeming Process, Pavan Kumar Singh

University of Kentucky Master's Theses

During the teeming process of molten steel from a ladle, a bathtub-type vortex may be formed in the ladle. The vortex entrains undesired slag on the surface into the tundish, lowering the quality. The formation of such vortices has been studied using two different scale models. Since the kinematic viscosity of water is similar to that of molten steel, the molten steel was simulated by water in the experiments. The Particle Image Velocimetry (PIV) technique was used to measure water flow patterns. Results show that the initial tangential velocity of water is responsible for the vortex formation. The effects of …

Characterization Of Seed Defects In Highly Specular Smooth Coated Surfaces, Pradeep Gnanaprakasam

University of Kentucky Master's Theses

Many smooth, highly specular coatings such as automotive paints are subjected to considerable performance demands as the customer expectations for appearance of coatings are continually increasing. Therefore it is vital to develop robust methods to monitor surface quality online. An automated visual assessment of specular coated surface that would not only provide a cost effective and reliable solution to the industries but also facilitate the implementation of a real-time feedback loop. The scope of this thesis is a subset of the inspection technology that facilitates real-time close loop control of the surface quality and concentrates on one common surface defect …

Experimental Study Of Active Separation Flow Control In A Low Pressure Turbine Blade Cascade Model, Mark Mcquilling

University of Kentucky Master's Theses

The flow field around a low pressure turbine (LPT) blade cascade model with and without flow control is examined using ejector nozzle (EN) and vortex generator jet (VGJ) geometries for separation control. The cascade model consists of 6 Pak-B Pratt andamp; Whitney low pressure turbine blades with Re = 30,000-50,000 at a free-stream turbulence intensity of 0.6%. The EN geometry consists of combined suction and blowing slots near the point of separation. The VGJs consist of a row of holes placed at an angle to the free-stream, and are tested at two locations of 69% and 10.5% of the suction …

Friction Stir Processing Of Aluminum Alloys, Rajeswari R. Itharaju

University of Kentucky Master's Theses

Friction stir processing (FSP) is one of the new and promising thermomechanical processing techniques that alters the microstructural and mechanical properties of the material in single pass to achieve maximum performance with low production cost in less time using a simple and inexpensive tool. Preliminary studies of different FS processed alloys report the processed zone to contain fine grained, homogeneous and equiaxed microstructure. Several studies have been conducted to optimize the process and relate various process parameters like rotational and translational speeds to resulting microstructure. But there is only a little data reported on the effect of the process parameters …

Multiscale Modeling And Analysis Of Failure And Stability During Superplastic Deformation -- Under Different Loading Conditions, Naveen Thuramalla

University of Kentucky Master's Theses

Superplastic forming (SPF) is a valuable near net shape fabrication method, used to produce very complex, contoured and monolithic structures that are often lighter, stronger and safer than the assemblies they replace. However, the widespread industrial use of Superplastic (SP) alloys is hindered by a number of issues including low production rate and limited predictive capabilities of stability during deformation and failure. Failure during SPD may result from geometrical macroscopic instabilities and/or microstructural aspects. However, the available failure criteria are either based on geometrical instabilities or microstructural features and do not account for both failure modes. The present study presents …

Numerical Investigation Of Thermal Transport Mechanisms During Ultra-Fast Laser Heating Of Nano-Films Using 3-D Dual Phase Lag (Dpl) Model, Illayathambi Kunadian

University of Kentucky Master's Theses

Ultra-fast laser heating of nano-films is investigated using 3-D Dual Phase Lag heat transport equation with laser heating at different locations on the metal film. The energy absorption rate, which is used to model femtosecond laser heating, is modified to accommodate for three-dimensional laser heating. A numerical solution based on an explicit finite-difference method is employed to solve the DPL equation. The stability criterion for selecting a time step size is obtained using von Neumann eigenmode analysis, and grid function convergence tests are performed. DPL results are compared with classical diffusion and hyperbolic heat conduction models and significant differences among …

Aeromechanics Of Low Reynolds Number Inflatable/Rigidizable Wings, Michiko Usui

University of Kentucky Master's Theses

Use of an inflatable/rigidizable wing is explored for Mars airplane designs. The BIG BLUE (Baseline Inflatable-wing Glider Balloon Launched Unmanned airplane Experiment) project was developed at the University of Kentucky, with an objective to demonstrate feasibility of this technology with a flight-test of an high-altitude glider with inflatable/rigidizable wings. The focus of this thesis research was to design and analyze the wing for this project. The wings are stowed in the fuselage, inflate during ascent, and rigidize with exposure to UV light. The design of wings was evaluated by using aerodynamic and finite element software and wind tunnel testing. The …

Validation Of Finite Element Program For Journal Bearings -- Static And Dynamic Properties, Raja Shekar Balupari

University of Kentucky Master's Theses

The analysis of bearing systems involves the prediction of their static and dynamic characteristics. The capability to compute the dynamic characteristics for hydrodynamic bearings has been added to Bearing Design System (BRGDS), a finite element program developed by Dr. R.W. Stephenson, and the results obtained were validated. In this software, a standard finite element implementation of the Reynolds equation is used to model the land region of the bearing with pressure degrees of freedom. The assumptions of incompressible flow, constant viscosity, and no fluid inertia terms are made. The pressure solution is integrated to give the bearing load, and the …

A Development Of A Computer Aided Graphic User Interface Postprocessor For Rotor Bearing Systems, Pavan Kumar Arise

University of Kentucky Master's Theses

Rotor dynamic analysis, which requires extensive amount of data and rigorous analytical processing, has been eased by the advent of powerful and affordable digital computers. By incorporating the processor and a graphical interface post processor in a single set up, this program offers a consistent and efficient approach to rotor dynamic analysis. The graphic user interface presented in this program effectively addresses the inherent complexities of rotor dynamic analyses by linking the required computational algorithms together to constitute a comprehensive program by which input data and the results are exchanged, analyzed and graphically plotted with minimal effort by the user. …

Testing And Validation Of A Correlation Based Transition Model Using Local Variables, Srinivas Reddy Likki

University of Kentucky Master's Theses

A systematic approach of testing and validating transition models is developed and employed in testing of a recently developed transition model. The testing methodology uses efficient computational tools and a wide range of test cases. The computational tools include a boundary layer code, single zone Navier Stokes solver, and a multi-block Navier Stokes solver which uses MPI and is capable of handling complex geometries and moving grids. Test cases include simple flat plate experiments, cascade experiments, and unsteady wake/blade interaction experiments. The test cases are used to test the predicting capabilities of the transition model under various effects such as …

Failure Rate Studies And Design Alternatives For Standup Forklift Trucks, Srinivas Jagarlamudi

University of Kentucky Master's Theses

Standup forklift trucks are extensively used primarily for material handling in high density warehouses. These forklifts over the years have been involved in severe accidents causing injuries and taking lives of the operator and that of people on the floor. The major accidents involving these trucks are tip-over, off the dock accidents, compartment intrusions and under the rack injuries. The objective of the work is to analyze the accident data and to provide a conceptual design to ensure safety of the operator riding the standup forklift trucks. The operator is assumed to be safe when retained within the compartment similar …

Micro Electro-Discharge Machining: Techniques And Procedures For Micro Fabrication, Christopher James Morgan

University of Kentucky Master's Theses

Using a Panasonic MG-72 Micro Electro-Discharge Machine, techniques and procedures are developed to fabricate complex microstructures in conductive materials and engineered ceramics.