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Computational Methods For Analyzing Rna Folding Landscapes And Its Applications, Yuan Li Jan 2012

Computational Methods For Analyzing Rna Folding Landscapes And Its Applications, Yuan Li

Electronic Theses and Dissertations

Non-protein-coding RNAs play critical regulatory roles in cellular life. Many ncRNAs fold into specific structures in order to perform their biological functions. Some of the RNAs, such as riboswitches, can even fold into alternative structural conformations in order to participate in different biological processes. In addition, these RNAs can transit dynamically between different functional structures along folding pathways on their energy landscapes. These alternative functional structures are usually energetically favored and are stable in their local energy landscapes. Moreover, conformational transitions between any pair of alternate structures usually involve high energy barriers, such that RNAs can become kinetically trapped by …


Hfs Plus File System Exposition And Forensics, Scott Ware Jan 2012

Hfs Plus File System Exposition And Forensics, Scott Ware

Electronic Theses and Dissertations

The Macintosh Hierarchical File System Plus, HFS +, or as it is commonly referred to as the Mac Operating System, OS, Extended, was introduced in 1998 with Mac OS X 8.1. HFS+ is an update to HFS, Mac OS Standard format that offers more efficient use of disk space, implements international friendly file names, future support for named forks, and facilitates booting on non-Mac OS operating systems through different partition schemes. The HFS+ file system is efficient, yet, complex. It makes use of B-trees to implement key data structures for maintaining meta-data about folders, files, and data. The implementation of …


Online Path Planning And Control Solution For A Coordinated Attack Of Multiple Unmanned Aerial Vehicles In A Dynamic Environment, Juan Vega-Nevarez Jan 2012

Online Path Planning And Control Solution For A Coordinated Attack Of Multiple Unmanned Aerial Vehicles In A Dynamic Environment, Juan Vega-Nevarez

Electronic Theses and Dissertations

The role of the unmanned aerial vehicle (UAV) has significantly expanded in the military sector during the last decades mainly due to their cost effectiveness and their ability to eliminate the human life risk. Current UAV technology supports a variety of missions and extensive research and development is being performed to further expand its capabilities. One particular field of interest is the area of the low cost expendable UAV since its small price tag makes it an attractive solution for target suppression. A swarm of these low cost UAVs can be utilized as guided munitions or kamikaze UAVs to attack …


Towards Evolving More Brain-Like Artificial Neural Networks, Sebastian Risi Jan 2012

Towards Evolving More Brain-Like Artificial Neural Networks, Sebastian Risi

Electronic Theses and Dissertations

An ambitious long-term goal for neuroevolution, which studies how artificial evolutionary processes can be driven to produce brain-like structures, is to evolve neurocontrollers with a high density of neurons and connections that can adapt and learn from past experience. Yet while neuroevolution has produced successful results in a variety of domains, the scale of natural brains remains far beyond reach. In this dissertation two extensions to the recently introduced Hypercube-based NeuroEvolution of Augmenting Topologies (HyperNEAT) approach are presented that are a step towards more brain-like artificial neural networks (ANNs). First, HyperNEAT is extended to evolve plastic ANNs that can learn …


Networking And Security Solutions For Vanet Initial Deployment Stage, Baber Aslam Jan 2012

Networking And Security Solutions For Vanet Initial Deployment Stage, Baber Aslam

Electronic Theses and Dissertations

Vehicular ad hoc network (VANET) is a special case of mobile networks, where vehicles equipped with computing/communicating devices (called "smart vehicles") are the mobile wireless nodes. However, the movement pattern of these mobile wireless nodes is no more random, as in case of mobile networks, rather it is restricted to roads and streets. Vehicular networks have hybrid architecture; it is a combination of both infrastructure and infrastructure-less architectures. The direct vehicle to vehicle (V2V) communication is infrastructure-less or ad hoc in nature. Here the vehicles traveling within communication range of each other form an ad hoc network. On the other …


Setpad: A Sketch-Based Tool For Exploring Discrete Math Set Problems, Travis Cossairt Jan 2012

Setpad: A Sketch-Based Tool For Exploring Discrete Math Set Problems, Travis Cossairt

Electronic Theses and Dissertations

We present SetPad, a new application prototype that lets computer science students explore discrete math problems by sketching set expressions using pen-based input. Students can manipulate the expressions interactively with the tool via pen or multi-touch interface. Likewise, discrete mathematics instructors can use SetPad to display and work through set problems via a projector to better demonstrate the solutions to the students. We discuss the implementation and feature set of the application, as well as results from both an informal perceived usefulness evaluation for students taking a computer science foundation exam in addition to a formal user study measuring the …


Study Of Human Activity In Video Data With An Emphasis On View-Invariance, Nazim Ashraf Jan 2012

Study Of Human Activity In Video Data With An Emphasis On View-Invariance, Nazim Ashraf

Electronic Theses and Dissertations

The perception and understanding of human motion and action is an important area of research in computer vision that plays a crucial role in various applications such as surveillance, HCI, ergonomics, etc. In this thesis, we focus on the recognition of actions in the case of varying viewpoints and different and unknown camera intrinsic parameters. The challenges to be addressed include perspective distortions, differences in viewpoints, anthropometric variations, and the large degrees of freedom of articulated bodies. In addition, we are interested in methods that require little or no training. The current solutions to action recognition usually assume that there …


Towards Real-Time Mixed Reality Matting In Natural Scenes, Nicholas Beato Jan 2012

Towards Real-Time Mixed Reality Matting In Natural Scenes, Nicholas Beato

Electronic Theses and Dissertations

In Mixed Reality scenarios, background replacement is a common way to immerse a user in a synthetic environment. Properly identifying the background pixels in an image or video is a dif- ficult problem known as matting. Proper alpha mattes usually come from human guidance, special hardware setups, or color dependent algorithms. This is a consequence of the under-constrained nature of the per pixel alpha blending equation. In constant color matting, research identifies and replaces a background that is a single color, known as the chroma key color. Unfortunately, the algorithms force a controlled physical environment and favor constant, uniform lighting. …


Efficient And Scalable Evaluation Of Continuous, Spatio-Temporal Queries In Mobile Computing Environments, Jonathan M. Cazalas Jan 2012

Efficient And Scalable Evaluation Of Continuous, Spatio-Temporal Queries In Mobile Computing Environments, Jonathan M. Cazalas

Electronic Theses and Dissertations

A variety of research exists for the processing of continuous queries in large, mobile environments. Each method tries, in its own way, to address the computational bottleneck of constantly processing so many queries. For this research, we present a two-pronged approach at addressing this problem. Firstly, we introduce an efficient and scalable system for monitoring traditional, continuous queries by leveraging the parallel processing capability of the Graphics Processing Unit. We examine a naive CPU-based solution for continuous range-monitoring queries, and we then extend this system using the GPU. Additionally, with mobile communication devices becoming commodity, location-based services will become ubiquitous. …


Algorithms For Rendering Optimization, Jared Johnson Jan 2012

Algorithms For Rendering Optimization, Jared Johnson

Electronic Theses and Dissertations

This dissertation explores algorithms for rendering optimization realizable within a modern, complex rendering engine. The first part contains optimized rendering algorithms for ray tracing. Ray tracing algorithms typically provide properties of simplicity and robustness that are highly desirable in computer graphics. We offer several novel contributions to the problem of interactive ray tracing of complex lighting environments. We focus on the problem of maintaining interactivity as both geometric and lighting complexity grows without effecting the simplicity or robustness of ray tracing. First, we present a new algorithm called occlusion caching for accelerating the calculation of direct lighting from many light …


A Study Of Localization And Latency Reduction For Action Recognition, Syed Zain Masood Jan 2012

A Study Of Localization And Latency Reduction For Action Recognition, Syed Zain Masood

Electronic Theses and Dissertations

The success of recognizing periodic actions in single-person-simple-background datasets, such as Weizmann and KTH, has created a need for more complex datasets to push the performance of action recognition systems. In this work, we create a new synthetic action dataset and use it to highlight weaknesses in current recognition systems. Experiments show that introducing background complexity to action video sequences causes a significant degradation in recognition performance. Moreover, this degradation cannot be fixed by fine-tuning system parameters or by selecting better feature points. Instead, we show that the problem lies in the spatio-temporal cuboid volume extracted from the interest point …


Gradient Based Mrf Learning For Image Restoration And Segmentation, Kegan Samuel Jan 2012

Gradient Based Mrf Learning For Image Restoration And Segmentation, Kegan Samuel

Electronic Theses and Dissertations

The undirected graphical model or Markov Random Field (MRF) is one of the more popular models used in computer vision and is the type of model with which this work is concerned. Models based on these methods have proven to be particularly useful in low-level vision systems and have led to state-of-the-art results for MRF-based systems. The research presented will describe a new discriminative training algorithm and its implementation. The MRF model will be trained by optimizing its parameters so that the minimum energy solution of the model is as similar as possible to the ground-truth. While previous work has …


Detecting, Tracking, And Recognizing Activities In Aerial Video, Vladimir Reilly Jan 2012

Detecting, Tracking, And Recognizing Activities In Aerial Video, Vladimir Reilly

Electronic Theses and Dissertations

In this dissertation, we address the problem of detecting humans and vehicles, tracking them in crowded scenes, and finally determining their activities in aerial video. Even though this is a well explored problem in the field of computer vision, many challenges still remain when one is presented with realistic data. These challenges include large camera motion, strong scene parallax, fast object motion, large object density, strong shadows, and insufficiently large action datasets. Therefore, we propose a number of novel methods based on exploiting scene constraints from the imagery itself to aid in the detection and tracking of objects. We show, …


Algorithms For Community Identification In Complex Networks, Mahadevan Vasudevan Jan 2012

Algorithms For Community Identification In Complex Networks, Mahadevan Vasudevan

Electronic Theses and Dissertations

First and foremost, I would like to extend my deepest gratitude to my advisor, Professor Narsingh Deo, for his excellent guidance and encouragement, and also for introducing me to this wonderful science of complex networks. Without his support this dissertation would not have been possible. I would also like to thank the members of my research committee, professors Charles Hughes, Ratan Guha, Mainak Chatterjee and Yue Zhao for their advice and guidance during the entire process. I am indebted to the faculty and the staff of the Department of Electrical Engineering and Computer Science for providing me the resources and …


Evolution Through The Search For Novelty, Joel Lehman Jan 2012

Evolution Through The Search For Novelty, Joel Lehman

Electronic Theses and Dissertations

I present a new approach to evolutionary search called novelty search, wherein only behavioral novelty is rewarded, thereby abstracting evolution as a search for novel forms. This new approach contrasts with the traditional approach of rewarding progress towards the objective through an objective function. Although they are designed to light a path to the objective, objective functions can instead deceive search into converging to dead ends called local optima. As a significant problem in evolutionary computation, deception has inspired many techniques designed to mitigate it. However, nearly all such methods are still ultimately susceptible to deceptive local optima because they …


Leveraging Help Requests In Pomdp Intelligent Tutors, Jeremiah Folsom-Kovarik Jan 2012

Leveraging Help Requests In Pomdp Intelligent Tutors, Jeremiah Folsom-Kovarik

Electronic Theses and Dissertations

Intelligent tutoring systems (ITSs) are computer programs that model individual learners and adapt instruction to help each learner differently. One way ITSs differ from human tutors is that few ITSs give learners a way to ask questions. When learners can ask for help, their questions have the potential to improve learning directly and also act as a new source of model data to help the ITS personalize instruction. Inquiry modeling gives ITSs the ability to answer learner questions and refine their learner models with an inexpensive new input channel. In order to support inquiry modeling, an advanced planning formalism is …


A Fitness Function Elimination Theory For Blackbox Optimization And Problem Class Learning, Gautham Anil Jan 2012

A Fitness Function Elimination Theory For Blackbox Optimization And Problem Class Learning, Gautham Anil

Electronic Theses and Dissertations

The modern view of optimization is that optimization algorithms are not designed in a vacuum, but can make use of information regarding the broad class of objective functions from which a problem instance is drawn. Using this knowledge, we want to design optimization algorithms that execute quickly (efficiency), solve the objective function with minimal samples (performance), and are applicable over a wide range of problems (abstraction). However, we present a new theory for blackbox optimization from which, we conclude that of these three desired characteristics, only two can be maximized by any algorithm. We put forward an alternate view of …


4d-Ct Lung Registration And Its Application For Lung Radiation Therapy, Yugang Min Jan 2012

4d-Ct Lung Registration And Its Application For Lung Radiation Therapy, Yugang Min

Electronic Theses and Dissertations

Radiation therapy has been successful in treating lung cancer patients, but its efficacy is limited by the inability to account for the respiratory motion during treatment planning and radiation dose delivery. Physics-based lung deformation models facilitate the motion computation of both tumor and local lung tissue during radiation therapy. In this dissertation, a novel method is discussed to accurately register 3D lungs across the respiratory phases from 4D-CT datasets, which facilitates the estimation of the volumetric lung deformation models. This method uses multi-level and multi-resolution optical flow registration coupled with thin plate splines (TPS), to address registration issue of inconsistent …