Digital Commons Network^™

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.

Finite Element Analysis And Reliability Study Of Multi-Piece Rims, Sandeep Chodavarapu

University of Kentucky Master's Theses

Multi-piece wheels or rims used on large vehicles such as trucks, tractors, trailers, buses and off-road machines have often been known for their dangerous properties because of the large number of catastrophic accidents involving them. The main causes for these accidents range from dislocation of the rim components in the assembly, mismatch of the components, manufacturing tolerances, corrosion of components to tires. A finite element analysis of a two-piece rim design similar to one manufactured by some of the prominent rim manufacturers in the USA is undertaken. A linear static deformation analysis is performed with the appropriate loading and boundary …

Scale Modeling Of Aluminum Melting Furnace, Sita Rama Raju S Penmetsa

University of Kentucky Master's Theses

Secondary (recycled) aluminum constitutes around 48% of the total aluminum used in the United States. Secondary aluminum melting is accomplished in large reverberatory furnaces, and improving its energy efficiency has been one of the major interests to aluminum industries. To assist the industries in improving energy efficiency in aluminum melting, an experimental research furnace (ERF), with 907 kg (2000 lbs) capacity, has been built at the Albany Research Center of the U.S. Department of Energy as part of this multi-partner research program. To verify that the experimental results obtained in the ERF furnace are valid for the operation of industrial …

Detailed Modeling Of Mufflers With Perforated Tubes Using Substructure Boundary Element Method, Balasubramanian Datchanamourty

University of Kentucky Master's Theses

Perforated tubes in mufflers are generally modeled by the transfer impedance approach since modeling the actual geometry of the perforated tubes with holes is very expensive due to the enormity of the boundary elements required. With the development of the substructuring technique which greatly reduces the number of elements required detailed modeling of the perforated tubes has become possible. In this thesis mufflers with perforated tubes are analyzed by modeling the actual geometry and locations of holes on the perforated tubes. The Direct-mixed-body boundary element method with substructuring is used to model the mufflers. Mufflers of various geometry containing perforated …

Fabrication And Characterization Of Deterministic Microasperities On Thrust Surfaces, Sarang Narayan Kortikar

University of Kentucky Master's Theses

The deterministic microasperities play a vital role in reducing the coefficient of friction and wear of thrust surfaces and improve the tribological properties of the surfaces. Deterministic microasperities have a specific pattern in terms of size, shape and spacing. These specified geometries are controllable and repeatable. The microasperities are micron scaled asperities and cavities on a surface that form the surface roughness. The present thesis shows the detailed process to fabricate the deterministic microasperities on thrust surfaces, i.e. stainless substrate, using micro-fabrication processes such as lapping and ultra-violet photolithography in combination with an electroplating (nickel) process. A Novel alignment technique …

Limitations Of Weftless Bead And Its Comparison With Cable Bead Design For Tires, Sandeep Singh Khatra

University of Kentucky Master's Theses

Weftless bead design used in tires has long been the cause of failure. This type of bead design is generally used in agriculture, buses, trucks and passenger car tires. The main problem with this kind of bead is the splice region. It has ten cut wires, five at each over and underlap region. It is known since 1950 that Weftless design of the tire bead had failures within about 5 cm from the end of the overlapping parallel wire ribbon. The cause for this failure is generally attributed to the mounting process in which the diameter of the tire bead …

Cover And Contents

Turkish Journal of Physics

No abstract provided.

Realizations Of The Osp(2,1) Superalgebra And Related Physical Systems, Hayri̇ye Tütüncüler, Ramazan Koç

Turkish Journal of Physics

Eigenvalues and eigenfunction of two-boson 2 \times 2 Hamiltonians in the framework of the superalgebra osp(2,1) are determined by presenting a similarity transformation. The Hamiltonians include two bosons and one fermion have been transformed in the form of the one variable differential equations and the conditions for its solvability have been discussed. It is observed that the Hamiltonians of the various physical systems can be written in terms of the generators of the osp(2,1) superalgebra and under some certain conditions their eigenstates can exactly be obtained. In particular, the procedure given here is useful in determining eigenstates of the Jaynes-Cummings …

Empirical Correlations Of Global Solar Radiation With Meteorological Data For Onne, Nigeria, Louis E. Akpabio, Sunday O. Udo, Sunday E. Etuk

Turkish Journal of Physics

Multiple linear regression models were developed to estimate the monthly average daily global solar radiation using ten parameters during a period of sixteen years (1984 to 1999) for Onne, Nigeria; the extraterrestrial radiation, average daily temperature, ratio of minimum and maximum daily temperature, relative humidity, ratio of sunshine duration, solar declination, average soil temperature, average pan evaporimeter, average rain fall and average daily dew. Even though up to ten variable correlations has been developed; the results showed that eight variable correlations with the highest value of correlation coefficient R gives the best result when considering the error terms (mean percentage …

Cover And Contents

Turkish Journal of Physics

No abstract provided.

Cover And Contents

Turkish Journal of Physics

No abstract provided.

The Legionella Pneumophila Pilt Homologue Dotb Exhibits Atpase Activity That Is Critical For Intracellular Growth, Jessica A. Sexton, Jerome S. Pinkner, Robyn Roth, John E. Heuser, Scott J. Hultgren, Joseph P. Vogel

Open Access Publications

No abstract provided.

Evolutionary And Functional Relationships Among The Nontypeable Haemophilus Influenzae Hmw Family Of Adhesins, Amy Z. Buscher, Katie Burmeister, Stephen J. Barenkamp, Joseph W. St. Geme Iii

Open Access Publications

No abstract provided.