Engineering Commons^™

Performance Of Pan-Tilt Tracker Based On The Pin-Hole Lens Model, Vikas Chandra Mehta

University of Kentucky Master's Theses

In the modern day, recognition and tracking of face or the iris is potentially one of the most powerful ways of differentiating between an authentic person and an imposter. Our method uses stereo vision to track the 3-Dimensional coordinates of a target equivalent to a person’s eyes and using a pan-tilt unit we target these areas for additional processing such as iris or facial imaging. One of the most important parts involved in tracking is the way the pan-tilt unit is calibrated. There have been techniques in the past where PTZ (Pan-tilt-zoom) digital camera has been used and calibrated using …

Understanding The Development Of Infant Feeding: A Spectral Analysis Approach, Pooja Vijaygopal

University of Kentucky Master's Theses

Feeding problems in preterm neonates stem from complications of early delivery. Attainment of independent feeding is a prerequisite for Neonatal Intensive Care Unit (NICU) discharges. Some quantitative studies of infant feeding involve excessive amounts of time for data processing. Multivariate spectral analysis was used to minimize time for investigation of variability in these rhythms. Auto and Cross-spectral parameters of the rhythms were correlated with Gestational Age (GA), Postmenstrual Age (PMA), Birthweight (BW), Days of Life (DOL), and Time Since First Nipple feeding (TSFN). Auto-spectral analysis showed 25.55% increase in Bandwidth of suck (bw-su) for a 2-week increase in GA (DOL …

Design And Analysis Of Nano-Gap Enhanced Surface Plasmon Resonance Sensors, Phillip Donald Keathley

University of Kentucky Master's Theses

Surface plasmon resonance (SPR) sensors are advantageous to other techniques of sensing chemical binding, offering quantitative, real-time, label-free results. Previous work has demonstrated the effectiveness of using dual-mode SPR sensors to differentiate between surface and background effects, making the sensors more robust to dynamic environments. This work demonstrates a technique that improves upon a previously optimized planar film dual-mode SPR sensor’s LOD by introducing a periodic array of subwavelength nano-gaps throughout the plasmon supporting material. First, general figures of merit for a sensor having an arbitrary number of modes are studied. Next, the mode effective index dispersion and magnetic field …

A Protocol Suite For Wireless Personal Area Networks, Karl E. Persson

University of Kentucky Doctoral Dissertations

A Wireless Personal Area Network (WPAN) is an ad hoc network that consists of devices that surround an individual or an object. Bluetooth^® technology is especially suitable for formation of WPANs due to the pervasiveness of devices with Bluetooth^® chipsets, its operation in the unlicensed Industrial, Scientific, Medical (ISM) frequency band, and its interference resilience. Bluetooth^® technology has great potential to become the de facto standard for communication between heterogeneous devices in WPANs.

The piconet, which is the basic Bluetooth^® networking unit, utilizes a Master/Slave (MS) configuration that permits only a single master and up to …

Micro-Fabricated Hydrogen Sensors Operating At Elevated Temperatures, Chi Lu

University of Kentucky Doctoral Dissertations

In this dissertation, three types of microfabricated solid-state sensors had been designed and developed on silicon wafers, aiming to detect hydrogen gas at elevated temperatures. Based on the material properties and sensing mechanisms, they were operated at 140°C, 500°C, and 300°C. The MOS-capacitor device working at 140°C utilized nickel instead of the widely-used expensive palladium, and the performance remained excellent. For very-high temperature sensing (500°C), the conductivity of the thermally oxidized TiO₂ thin film based on the anodic aluminum oxide (AAO) substrate changed 25 times in response to 5 ppm H₂ and the response transient times were just …

Fabrication Of Nanostructures For Improved Performance Of Electrochemical Sensors And For Reference Compensation In Localized Surface Plasmon Resonance Sensors, Prashanthi Para

University of Kentucky Master's Theses

L‐glutamate is associated with several neurological disorders; thus, monitoring fast dynamics of L‐glutamate is of great importance in the field of neuroscience. Electrode miniaturization demanded by many applications leads to reduced surface area and decreased amounts of immobilized enzymes on coated electrodes. As a result, lower signal‐to‐noise ratios are observed for oxidase‐enzyme based sensors. To increase the signal‐to‐noise ratio we have developed a process to fabricate micro‐ and nano‐ structures on the microelectrode surface.

Localized surface‐plasmon resonances (SPR) has been extensively used to design label‐free biosensors that can monitor receptor‐ligand interactions. A major challenge with localized SPR sensors is that …

An Evaluation Of The Traveling Wave Ultrasonic Motor For Force Feedback Applications, Nishant Venkatesan

University of Kentucky Master's Theses

The traveling wave ultrasonic motor is considered for use in haptic devices where a certain input-output relation is desired between the applied force and the resulting motion. Historically, DC motors have been the standard choice for this purpose. Owing to its unique characteristics, the ultrasonic motors have been considered an attractive alternative. However, there are some limitations when using the ultrasonic motor for force-feedback applications. In particular, direct torque control is difficult, and the motor can only supply torque in the direction of motion. To accommodate these limitations we developed an indirect control approach. The experimental results demonstrate that the …

Joint Visual And Wireless Tracking System, Viswajith Karapoondi Nott

University of Kentucky Master's Theses

Object tracking is an important component in many applications including surveillance, manufacturing, inventory tracking, etc. The most common approach is to combine a surveillance camera with an appearance-based visual tracking algorithm. While this approach can provide high tracking accuracy, the tracker can easily diverge in environments where there are much occlusions. In recent years, wireless tracking systems based on different frequency ranges are becoming more popular. While systems using ultra-wideband frequencies suffer similar problems as visual systems, there are systems that use frequencies as low as in those in the AM band to circumvent the problems of obstacles, and exploit …

Tunable Laser Interrogation Of Surface Plasmon Resonance Sensors, Vaibhav Badjatya

University of Kentucky Master's Theses

Surface plasmons are bound TM polarized electromagnetic waves that propagate along the interface of two materials with real dielectric constants of opposite signs. Surface plasmon resonance (SPR) sensors make use of the surface plasmon waves to detect refractive index changes occurring near this interface. For sensing purposes, this interface typically consists of a metal layer, usually gold or silver, and a liquid dielectric. SPR sensors usually measure the shift in resonance wavelength or resonance angle due to index changes adjacent to the metal layer. However this restricts the limit of detection (LOD), as the regions of low slope (intensity vs. …

3d Reconstruction Using Multi-View Imaging System, Conglin Huang

University of Kentucky Master's Theses

This thesis presents a new system that reconstructs the 3D representation of dental casts. To maintain the integrity of the 3D representation, a standard model is built to cover the blind spots that the camera cannot reach. The standard model is obtained by scanning a real human mouth model with a laser scanner. Then the model is simplified by an algorithm which is based on iterative contraction of vertex pairs. The simplified standard model uses a local parametrization method to obtain the curvature information. The system uses a digital camera and a square tube mirror in front of the camera …

Development Of A Reusable Cubesat Satellite Bus Architecture For The Kysat-1 Spacecraft, Tyler James Doering

University of Kentucky Master's Theses

This thesis describes the design, implementation and testing of a spacecraft bus implemented on KySat-1, a picosatellite scheduled to launch late 2009 to early 2010. The spacecraft bus is designed to be a robust reusable bus architecture using commercially available off the shelf components and subsystems. The bus designed and implemented for the KySat-1 spacecraft will serve as the basis for a series of future Kentucky Space Consortium missions. The spacecraft bus consists of attitude determination and control subsystem, communications subsystem, command and data handling subsystem, thermal subsystem, power subsystem, and structures and mechanisms. The spacecraft bus design is described …

Nanomechanical Characterizations Of High Temperature Polymer Matrix Composite Resin: Pmr-15 Polyimide, David C. Jones

University of Kentucky Master's Theses

High Temperature Polymer Matrix Composites (HTPMCs) are widely used by the aerospace industry today because of their high specific strengths, light weight, and the ability to custom tailor their mechanical properties to individual applications. Because of the harsh environmental conditions these materials experience during service use, these composite structures are susceptible to a high rate of thermo-oxidative degradation that ultimately causes premature failure in service. The current knowledge base is lacking in the fundamental spatial variability of the constituent materials upon aging, which precludes composite developers from predicting lifetime mechanical properties of the composites in use. The current study summarizes …

Reduced Frequency Motor Starting For Third World Power Systems, Taylor A. Begley

University of Kentucky Master's Theses

People in modern industrialized societies live a blessed life relative to those who do not when it comes to some modern conveniences. While many think nothing of flipping on a light switch or running electric appliances, there are people in third world countries could not imagine such things. As service projects are being undertaken to bring such conveniences to those less fortunate, there often is the harsh reality of a strict budget. An item that commands a large portion of said budget is often the diesel generator used to provide the facility with electricity. Generators serving motor loads are typically …

Electrical And Mechanical Properties Of Mwcnt Filled Conductive Adhesives On Lead Free Surface Finished Pcb's., Keerthi Varma Mantena

University of Kentucky Master's Theses

Electrically conductive adhesives (ECA) are an alternative to tin/lead solders for attaching Surface Mount Devices (SMD) in electronic assemblies. ECAs are mixtures of a polymer binder (for adhesion) and conductive filler (for electrical conductivity). They bring more conductivity, higher strength, less weight and longer durability than metal alloys. ECAs can offer numerous advantages such as fewer processing steps, lower processing temperature and fine pitch capability. Multi walled carbon nanotubes (MWCNT) were used as conductive fillers in this research because of their novel electronic and mechanical properties.

The high aspect ratio of the nanotubes makes it possible to percolate at low …

An Algorithm To Solve The Associative Parallel Machine Scheduling Problem, Mohannad Abdelrahman Shuaib

University of Kentucky Master's Theses

Effective production scheduling is essential for improved performance. Scheduling strategies for various shop configurations and performance criteria have been widely studied. Scheduling in parallel machines (PM) is one among the many scheduling problems that has received considerable attention in the literature. An even more complex scheduling problem arises when there are several PM families and jobs are capable of being processed in more than one such family. This research addresses such a situation, which is defined as an Associative Parallel Machine scheduling (APMS) problem. This research presents the SAPT-II algorithm that solves a highly constrained APMS problem with the objective …

Mpi Within A Gpu, Bobby Dalton Young

University of Kentucky Master's Theses

GPUs offer high-performance floating-point computation at commodity prices, but their usage is hindered by programming models which expose the user to irregularities in the current shared-memory environments and require learning new interfaces and semantics.

This thesis will demonstrate that the message-passing paradigm can be conceptually cleaner than the current data-parallel models for programming GPUs because it can hide the quirks of current GPU shared-memory environments, as well as GPU-specific features, behind a well-established and well-understood interface. This will be shown by demonstrating a proof-of-concept MPI implementation which provides cleaner, simpler code with a reasonable performance cost. This thesis will also …

Separating Instruction Fetches From Memory Accesses : Ilar (Instruction Line Associative Registers), Nien Yi Lim

University of Kentucky Master's Theses

Due to the growing mismatch between processor performance and memory latency, many dynamic mechanisms which are “invisible” to the user have been proposed: for example, trace caches and automatic pre-fetch units. However, these dynamic mechanisms have become inadequate due to implicit memory accesses that have become so expensive. On the other hand, compiler-visible mechanisms like SWAR (SIMD Within A Register) and LARs (Line Associative Registers) are potentially more effective at improving data access performance. This thesis investigates applying the same ideas to improve instruction access.

ILAR (Instruction LARs) store instructions in wide registers. Instruction blocks are explicitly loaded into ILAR, …

Verification And Debug Techniques For Integrated Circuit Designs, David Allen Crutchfield

University of Kentucky Master's Theses

Verification and debug of integrated circuits for embedded applications has grown in importance as the complexity in function has increased dramatically over time. Various modeling and debugging techniques have been developed to overcome the overwhelming challenge. This thesis attempts to address verification and debug methods by presenting an accurate C model at the bit and algorithm level coupled with an implemented Hardware Description Language (HDL). Key concepts such as common signal and variable naming conventions are incorporated as well as a stepping function within the implemented HDL. Additionally, a common interface between low-level drivers and C models is presented for …

Collective Communication And Barrier Synchronization On Nvidia Cuda Gpu, Diego Alejandro Rivera-Polanco

University of Kentucky Master's Theses

GPUs (Graphics Processing Units) employ a multi-threaded execution model using multiple SIMD cores. Compared to use of a single SIMD engine, this architecture can scale to more processing elements. However, GPUs sacrifice the timing properties which made barrier synchronization implicit and collective communication operations fast.

This thesis demonstrates efficient methods by which these aggregate functions can be implemented using unmodified NVIDIA CUDA GPUs. Although NVIDIA's highest “compute capability" GPUs provide atomic memory functions, they have order N execution time. In contrast, the methods proposed here take advantage of basic properties of the GPU architecture to make implementations that are both …

Enhancements To The Generalized Sidelobe Canceller For Audio Beamforming In An Immersive Environment, Phil Townsend

University of Kentucky Master's Theses

The Generalized Sidelobe Canceller is an adaptive algorithm for optimally estimating the parameters for beamforming, the signal processing technique of combining data from an array of sensors to improve SNR at a point in space. This work focuses on the algorithm’s application to widely-separated microphone arrays with irregular distributions used for human voice capture. Methods are presented for improving the performance of the algorithm’s blocking matrix, a stage that creates a noise reference for elimination, by proposing a stochastic model for amplitude correction and enhanced use of cross correlation for phase correction and time-difference of arrival estimation via a correlation …

Regeneration Of Damaged Growth Plate Using Igf-I Plasmid-Releasing Porous Plga Scaffolds, Nirmal Ravi

University of Kentucky Doctoral Dissertations

Growth plate injuries account for 15-30% of long bone fractures in children. About 10% of these result in significant growth disturbances due to formation of a boney bar. If not treated correctly, this can lead to life-lasting consequences of limb length inequalities and angular deformities. Current treatments for growth plate injuries include removal of boney bar and insertion of fat, silicone, bone cement, etc.. This treatment y is inadequate, leaving almost half of these patients with continued deformities. This dissertation reports characterization of a DNA–containing porous poly(lactic-co-glycolic acid) (PLGA) scaffold system, chondrogenesis using insulin-like growth factor I (IGF-I) plasmid-releasing scaffolds …

Three-Dimensional Free Surface Non-Hydrostatic Modeling Of Plunging Water With Turbulence And Air Entrained Transport, Tien Mun Yee

University of Kentucky Doctoral Dissertations

The advance in computational fluid dynamics in recent years has provided the opportunity for many fluid dynamic problems to be analyzed numerically. One such problem concerns the modeling of plunging water into a still water body, often encountered in pump stations. Air bubbles introduced into the system by the plunging jet can be a significant problem, especially when consumed into operating pumps. The classical approach to investigate the hydrodynamics of plunging jet in pump stations is by physical model studies. This approach is time consuming, tedious and costly. The availability of computational power today, along with appropriate numerical techniques, allows …

Analytical Strip Method To Antisymmetric Laminated Plates, Liecheng Sun

University of Kentucky Doctoral Dissertations

An Analytical Strip Method (ASM) for the analysis of stiffened and non-stiffened antisymmetric laminated composite plates is derived by considering the bending-extension coupling effect for bending, free vibration and buckling. A system of three equations of equilibrium, governing the general response of arbitrarily laminated composite plates, is reduced to a single eighth order partial differential equation in terms of a displacement function. The displacement function is solved in a single series form to determine the displacement, fundamental frequency, and buckling load of antisymmetric cross-ply and angle-ply laminated composite plates. The solution is applicable to rectangular plates with two opposite edges …

Utilizing Mixed Surfactants For Simultaneous Pore Templating And Active Site Formation In Metal Oxides, Mohammed Shahidur Rahman

University of Kentucky Doctoral Dissertations

Self-assembled nonionic alkyl glycoside surfactants are of interest for creating functional adsorption and catalytic sites at the surface of mesoporous metal oxides, but they typically impart poor long-range order when used as pore templates. Improved order and control over the functional site density may be achieved by mixing them with a cationic surfactant. To confirm this hypothesis, we investigate the lyotropic liquid crystalline (LLC) phase behavior of aqueous solutions of the functional nonionic surfactant n-dodecyl β-D-maltoside (C₁₂G₂) and cationic cetyltrimethylammonium bromide (C₁₆TAB). A ternary phase diagram of the C₁₆TAB-C₁₂G_{2 …}

Vortex Model Of Open Channel Flows With Gravel Beds, Brian James Belcher

University of Kentucky Doctoral Dissertations

Turbulent structures are known to be important physical processes in gravel-bed rivers. A number of limitations exist that prohibit the advancement and prediction of turbulence structures for optimization of civil infrastructure, biological habitats and sediment transport in gravel-bed rivers. This includes measurement limitations that prohibit characterization of size and strength of turbulent structures in the riverine environment for different case studies as well as traditional numerical modeling limitations that prohibit modeling and prediction of turbulent structure for heterogeneous beds under high Reynolds number flows using the Navier-Stokes equations. While these limitations exist, researchers have developed various theories for the structure …

Applications Of Computational Fluid Dynamics To Planetary Atmospheres, Xiaolong Deng

University of Kentucky Doctoral Dissertations

Computational Fluid Dynamics (CFD) has been applied to many areas. As one of the most important fluids, the atmosphere is closely related to people’s life. Studying the atmospheres on other planets can help people understand the Earth’s atmosphere and the climate and weather phenomena in it. Because of the complexity of a planetary atmosphere and the limitation of observations, applying CFD to the study of planetary atmospheres is becoming more and more popular. This kind of CFD simulations will also help people design the mission to the extra planets.

In this dissertation, through CFD simulations, we studied the three important …

Production Sequencing And Stability Analysis Of A Just-In-Time System With Sequence Dependent Setups, John Thomas Henninger

University of Kentucky Doctoral Dissertations

Just-In-Time (JIT) production systems is a popular area for researchers but real-world issues such as sequence dependent setups are often overlooked. This research investigates an approach for determining stability and an approach for mixed product sequencing in production systems with sequence dependent setups and buffer thresholds which signal replenishment of a given buffer. Production systems in this research operate under JIT pull production principles by producing only when demand exists and idle when no demand exists.

In the first approach, an iterative method is presented to determine stability for a multi-product production system that operates with replenishment signals and may …

Microstructural Evolution And Physical Behavior Of Palladium And Osmium-Ruthenium Noble Metal Films, Wen-Chung Li

University of Kentucky Doctoral Dissertations

Nanostructured noble metals exhibit novel physical, mechanical and chemical behavior, and hold promise for applications such as gas sensing and electron emission. A strong emphasis was placed on the processing and characterization of these materials, in the form of nanoporous or nanocrystalline thin films. Palladium-based and osmium-ruthenium alloys were investigated in this dissertation research and will be presented as follows:

(1) Preparation and Characterization of Nanoporous Metal Thin Films

(2) Characterization of Osmium-Ruthenium Coatings

Nanoporous palladium (np-Pd) thin films were prepared by dealloying co-sputtered palladium-nickel precursor alloys. Nanoporous structures were created with 3-D interconnected ligaments and open pores. Size of …

Visualization And Characterization Of Ultrasonic Cavitating Atomizer And Other Automotive Paint Sprayers Using Infrared Thermography, Nelson Kudzo Akafuah

University of Kentucky Doctoral Dissertations

The disintegration of a liquid jet emerging from a nozzle has been under investigation for several decades. A direct consequence of the liquid jet disintegration process is droplet formation. The breakup of a liquid jet into discrete droplets can be brought about by the use of a diverse forcing mechanism. Cavitation has been thought to assist the atomization process. Previous experimental studies, however, have dealt with cavitation as a secondary phenomenon assisting the primary atomization mechanism. In this dissertation, the role of the energy created by the collapse of cavitation bubbles, together with the liquid pressure perturbation is explicitly configured …

Manufacture, Characterization, And Application Of Multiwall Carbon Nanotube Composite Crylonitrile-Butadiene-Styrene, Daniel Ray Bortz

University of Kentucky Master's Theses

Carbon nanotubes have been studied for nearly two decades and their amazing properties continue to spur intense investigation in the area of polymer composites. In terms of potential commercialization, mutiwall carbon nanotubes (MWCNTs) are currently the most prevalent and economically viable form of nanotubes. Uncovering innovative means to take full advantage of their properties remains a fundamental issue. In this thesis, viability of their use to reinforce polymeric systems is reported. Acrylonitrilebutadiene- styrene (ABS) was used as the host matrix. MWCNTs were introduced to the ABS matrix via melt compounding. The resulting composite was thoroughly rheologically, thermally, and mechanically characterized. …