Physical Sciences and Mathematics Commons^™

Exploration And Comparison Of Methods For Combining Population- And Family-Based Genetic Association Using The Genetic Analysis Workshop 17 Mini-Exome, David W. Fardo, Anthony R. Druen, Jinze Liu, Lucia Mirea, Claire Infante-Rivard, Patrick Breheny

Biostatistics Faculty Publications

We examine the performance of various methods for combining family- and population-based genetic association data. Several approaches have been proposed for situations in which information is collected from both a subset of unrelated subjects and a subset of family members. Analyzing these samples separately is known to be inefficient, and it is important to determine the scenarios for which differing methods perform well. Others have investigated this question; however, no extensive simulations have been conducted, nor have these methods been applied to mini-exome-style data such as that provided by Genetic Analysis Workshop 17. We quantify the empirical power and false-positive …

Numerical Modeling Of The Cn Spectral Emission Of The Stardust Re-Entry Vehicle, Alexandre Martin, Erin D. Farbar, Iain D. Boyd

Mechanical Engineering Faculty Publications

Re-entry vehicles designed for space exploration are usually equipped with thermal protection systems made of ablative material. In order to properly model and predict the aerothermal environment of the vehicle, it is imperative to account for the gases produced by ablation processes. In the case of charring ablators, where an inner resin is pyrolyzed at a relatively low temperature, the composition of the gas expelled into the boundary layer is complex and may lead to thermal chemical reactions that cannot be captured with simple ow chemistry models. In order to obtain better predictions, an appropriate gas ow chemistry model needs …

A Computational Tool For Estimating Off-Target Application Areas In Agricultural Fields, Rodrigo S. Zandonadi, Joe D. Luck, Timothy S. Stombaugh, Michael P. Sama, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

A computational method for estimating off-target application areas based on the machine-controlled section width and the field shape was developed and implemented in software with a graphical user interface written in the MatLab environment. The program, which is called the Field Coverage Analysis Tool (FieldCAT), includes three modules: data import, data preparation, and coverage analysis. Nine field boundaries were evaluated to test the software using controlled section widths from 0.5 to 27 m and various swath orientations. The estimated off-target application area from the widest section width varied from 9% to 24% depending on the shape and size of the …

A Reliability-Based Routing Protocol For Vehicular Ad-Hoc Networks, James Bernsen

University of Kentucky Master's Theses

Vehicular Ad hoc NETworks (VANETs), an emerging technology, would allow vehicles to form a self-organized network without the aid of a permanent infrastructure. As a prerequisite to communication in VANETs, an efficient route between communicating nodes in the network must be established, and the routing protocol must adapt to the rapidly changing topology of vehicles in motion. This is one of the goals of VANET routing protocols. In this thesis, we present an efficient routing protocol for VANETs, called the Reliable Inter-VEhicular Routing (RIVER) protocol. RIVER utilizes an undirected graph that represents the surrounding street layout where the vertices of …

Cluster-Based Term Weighting And Document Ranking Models, Keerthiram Murugesan

University of Kentucky Master's Theses

A term weighting scheme measures the importance of a term in a collection. A document ranking model uses these term weights to find the rank or score of a document in a collection. We present a series of cluster-based term weighting and document ranking models based on the TF-IDF and Okapi BM25 models. These term weighting and document ranking models update the inter-cluster and intra-cluster frequency components based on the generated clusters. These inter-cluster and intra-cluster frequency components are used for weighting the importance of a term in addition to the term and document frequency components. In this thesis, we …

Three Dimensional Modeling And Animation Of Facial Expressions, Alice J. Lin

University of Kentucky Doctoral Dissertations

Facial expression and animation are important aspects of the 3D environment featuring human characters. These animations are frequently used in many kinds of applications and there have been many efforts to increase the realism. Three aspects are still stimulating active research: the detailed subtle facial expressions, the process of rigging a face, and the transfer of an expression from one person to another. This dissertation focuses on the above three aspects.

A system for freely designing and creating detailed, dynamic, and animated facial expressions is developed. The presented pattern functions produce detailed and animated facial expressions. The system produces realistic …

Checkpointing And Recovery In Distributed And Database Systems, Jiang Wu

Theses and Dissertations--Computer Science

A transaction-consistent global checkpoint of a database records a state of the database which reflects the effect of only completed transactions and not the re- sults of any partially executed transactions. This thesis establishes the necessary and sufficient conditions for a checkpoint of a data item (or the checkpoints of a set of data items) to be part of a transaction-consistent global checkpoint of the database. This result would be useful for constructing transaction-consistent global checkpoints incrementally from the checkpoints of each individual data item of a database. By applying this condition, we can start from any useful checkpoint of …

On Simple But Hard Random Instances Of Propositional Theories And Logic Programs, Gayathri Namasivayam

University of Kentucky Doctoral Dissertations

In the last decade, Answer Set Programming (ASP) and Satisfiability (SAT) have been used to solve combinatorial search problems and practical applications in which they arise. In each of these formalisms, a tool called a solver is used to solve problems. A solver takes as input a specification of the problem – a logic program in the case of ASP, and a CNF theory for SAT – and produces as output a solution to the problem. Designing fast solvers is important for the success of this general-purpose approach to solving search problems. Classes of instances that pose challenges to solvers …

Modeling And Quantitative Analysis Of White Matter Fiber Tracts In Diffusion Tensor Imaging, Xuwei Liang

University of Kentucky Doctoral Dissertations

Diffusion tensor imaging (DTI) is a structural magnetic resonance imaging (MRI) technique to record incoherent motion of water molecules and has been used to detect micro structural white matter alterations in clinical studies to explore certain brain disorders. A variety of DTI based techniques for detecting brain disorders and facilitating clinical group analysis have been developed in the past few years. However, there are two crucial issues that have great impacts on the performance of those algorithms. One is that brain neural pathways appear in complicated 3D structures which are inappropriate and inaccurate to be approximated by simple 2D structures, …

Resource Allocation And Efficient Routing In Wireless Networks, Jianjun Yang

University of Kentucky Doctoral Dissertations

In wireless networks, devices (nodes) are connected by wireless links. An important issue is to set up high quality (high bandwidth) and efficient routing paths when one node wants to send packets to other nodes. Resource allocation is the foundation to guarantee high quality connections. In addition, it is critical to handle void areas in order to set up detour-free paths. Moreover, fast message broadcasting is essential in mobile wireless networks. Thus, my research includes dynamic channel allocation in wireless mesh networks, geographic routing in Ad Hoc networks, and message broadcasting in vehicular networks.

The quality of connections in a …

A Secure Online Payment System, Shristi Pant

Theses and Dissertations--Computer Science

An online payment system allows a customer to make a payment to an online merchant or a service provider. Payment gateways, a channel between customers and payment processors, use various security tools to secure a customer’s payment information, usually debit or credit card information, during an online payment. However, the security provided by a payment gateway cannot completely protect a customer’s payment information when a merchant also has the ability to obtain the payment information in some form. Furthermore, not all merchants provide a secure payment environment to their customers and, despite having a standard payment policy, adhere to it. …

Construction Of Efficient Authentication Schemes Using Trapdoor Hash Functions, Santosh Chandrasekhar

University of Kentucky Doctoral Dissertations

In large-scale distributed systems, where adversarial attacks can have widespread impact, authentication provides protection from threats involving impersonation of entities and tampering of data. Practical solutions to authentication problems in distributed systems must meet specific constraints of the target system, and provide a reasonable balance between security and cost. The goal of this dissertation is to address the problem of building practical and efficient authentication mechanisms to secure distributed applications. This dissertation presents techniques to construct efficient digital signature schemes using trapdoor hash functions for various distributed applications. Trapdoor hash functions are collision-resistant hash functions associated with a secret trapdoor …