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A Comparative Study Of Ant Colony Optimization, Matthew Becker
A Comparative Study Of Ant Colony Optimization, Matthew Becker
Electronic Theses and Dissertations
Ant Colony Optimization (ACO) belongs to a class of biologically-motivated approaches to computing that includes such metaheuristics as artificial neural networks, evolutionary algorithms, and artificial immune systems, among others. Emulating to varying degrees the particular biological phenomena from which their inspiration is drawn, these alternative computational systems have succeeded in finding solutions to complex problems that had heretofore eluded more traditional techniques. Often, the resulting algorithm bears little resemblance to its biological progenitor, evolving instead into a mathematical abstraction of a singularly useful quality of the phenomenon. In such cases, these abstract computational models may be termed biological metaphors. Mindful …
Simplified Low Copy Number Dna Analysis By Post Pcr Purification, Pamela Smith
Simplified Low Copy Number Dna Analysis By Post Pcr Purification, Pamela Smith
Electronic Theses and Dissertations
Frequently evidentiary items contain an insufficient quantity of DNA to obtain complete or even partial DNA profiles using standard forensic gentotyping techniques. Here, various methods of post PCR purification were evaluated for their effects on the sensitivity of fluophore-based allelic detection. A method of post PCR purification is described which increases the sensitivity of standard 28 cycle PCR such that low copy number DNA templates (<100 pg DNA) can be analyzed. Full profiles were consistently obtained with as little as 20 pg template DNA without increased cycle number. In mock case type samples with dermal ridge fingerprints, genetic profiles were obtained by amplification with 28 cycles followed by post-PCR purification whereas no profiles were obtained without purification of the PCR product. Allele drop-out, increased stutter, and contamination (allele drop-in) typical of LCN analysis were observed. A single incident of contamination was observed in a reagent blank (not duplicated upon re-amplification) however, no contamination was observed in negative amplification controls.
High Birefringence And Low Viscosity Liquid Crystals, Chien-Hui Wen
High Birefringence And Low Viscosity Liquid Crystals, Chien-Hui Wen
Electronic Theses and Dissertations
In this dissertation, liquid crystal (LC) materials and devices are investigated in order to meet the challenges for photonics and displays applications. We have studied three kinds of liquid crystal materials: positive dielectric anisotropic LCs, negative dielectric anisotropic LCs, and dual- frequency LCs. For the positive dielectric anisotropic LCs, we have developed some high birefringence isothiocyanato tolane LC compounds with birefringence ~0.4, and super high birefringence isothiocyanato biphenyl-bistolane LC compounds with birefringence as high as ~0.7. Moreover, we have studied the photostability of several high birefringence LC compounds, mixtures, and LC alignment layers in order to determine the failure mechanism …
On The Use Of Gaussian Filter Functions For Adaptive Optics, Merfit Assad
On The Use Of Gaussian Filter Functions For Adaptive Optics, Merfit Assad
Electronic Theses and Dissertations
For adaptive optic systems, the use of aperture filter functions calculated using various Zernike modes can be useful in removing lower-order aberrations caused by atmospheric turbulence. Traditionally, these filter functions are calculated using the step function depicting a hard aperture that introduces integrals that are sometimes difficult to integrate and must be done numerically. The Gaussian method can be used in place of the conventional method for calculating the aperture filter functions. Evaluation of the Gaussian approximation for modeling a finite receiver aperture can be made by comparison of reduction in phase variance with results achieved using the conventional method. …
Sub-Pixel Registration In Computational Imaging And Applications To Enhancement Of Maxillofacial Ct Data, Murat Balci
Sub-Pixel Registration In Computational Imaging And Applications To Enhancement Of Maxillofacial Ct Data, Murat Balci
Electronic Theses and Dissertations
In computational imaging, data acquired by sampling the same scene or object at different times or from different orientations result in images in different coordinate systems. Registration is a crucial step in order to be able to compare, integrate and fuse the data obtained from different measurements. Tomography is the method of imaging a single plane or slice of an object. A Computed Tomography (CT) scan, also known as a CAT scan (Computed Axial Tomography scan), is a Helical Tomography, which traditionally produces a 2D image of the structures in a thin section of the body. It uses X-ray, which …
Epidemiological Models For Mutating Pathogens With Temporary Immunity, Neeta Singh
Epidemiological Models For Mutating Pathogens With Temporary Immunity, Neeta Singh
Electronic Theses and Dissertations
Significant progress has been made in understanding different scenarios for disease transmissions and behavior of epidemics in recent years. A considerable amount of work has been done in modeling the dynamics of diseases by systems of ordinary differential equations. But there are very few mathematical models that deal with the genetic mutations of a pathogen. In-fact, not much has been done to model the dynamics of mutations of pathogen explaining its effort to escape the host's immune defense system after it has infected the host. In this dissertation we develop an SIR model with variable infection age for the transmission …
Multiple View Geometry For Video Analysis And Post-Production, Xiaochun Cao
Multiple View Geometry For Video Analysis And Post-Production, Xiaochun Cao
Electronic Theses and Dissertations
Multiple view geometry is the foundation of an important class of computer vision techniques for simultaneous recovery of camera motion and scene structure from a set of images. There are numerous important applications in this area. Examples include video post-production, scene reconstruction, registration, surveillance, tracking, and segmentation. In video post-production, which is the topic being addressed in this dissertation, computer analysis of the motion of the camera can replace the currently used manual methods for correctly aligning an artificially inserted object in a scene. However, existing single view methods typically require multiple vanishing points, and therefore would fail when only …
Antenna-Coupled Infrared And Millimeter-Wave Detectors: Fabrication, Measurement And Optimization, Charles Middleton
Antenna-Coupled Infrared And Millimeter-Wave Detectors: Fabrication, Measurement And Optimization, Charles Middleton
Electronic Theses and Dissertations
Antenna-coupled detectors provide uncooled, cost-effective solutions for infrared and millimeter-wave imaging. This work describes the design, fabrication, measurement, and optimization of several types of antenna-coupled detectors for LWIR (8 - 12 µm) and 94 GHz radiation. Two types of millimeter-wave antenna-coupled detectors were fabricated and tested: a slot antenna coupled to a bolometer, and a patch antenna coupled to a SiC Schottky diode. Electromagnetic modeling of the antennas helped guide the design of antennas with better impedance matching to the detectors. Schottky diodes are discussed as detectors for millimeter-wave and infrared radiation, with the goal of increasing the cutoff frequency …
All-Semiconductor High Power Mode-Locked Laser System, Kyungbum Kim
All-Semiconductor High Power Mode-Locked Laser System, Kyungbum Kim
Electronic Theses and Dissertations
All-optical synchronization and its application in advanced optical communications have been investigated in this dissertation. Dynamics of all-optical timing synchronization (clock recovery) using multi-section gain-coupled distributed-feedback (MS-GC DFB) lasers are discussed. A record speed of 180-GHz timing synchronization has been demonstrated using this device. An all-optical carrier synchronization (phase and polarization recovery) scheme from PSK (phase shift keying) data is proposed and demonstrated for the first time. As an application of all-optical synchronization, the characterization of advanced modulation formats using a linear optical sampling technique was studied. The full characterization of 10-Gb/s RZ-BPSK (return-to-zero binary PSK) data has been demonstrated. …
Sensor-Based Computing Techniques For Real-Time Traffic Evacuation Management, Georgiana Hamza-Lup
Sensor-Based Computing Techniques For Real-Time Traffic Evacuation Management, Georgiana Hamza-Lup
Electronic Theses and Dissertations
The threat of terrorist incidents is higher than ever before and devastating acts, such as the terrorist attacks on the World Trade Center and the Pentagon, have left many concerns about the possibility of future incidents and their potential impact. Unlike some natural disasters that can be anticipated, terrorist attacks are sudden and unexpected. Even if sometimes we do have partial information about a possible attack, it is generally not known exactly where, when, or how an attack will occur. This lack of information posses great challenges on those responsible for security, specifically, on their ability to respond fast, whenever …
Video Content Extraction: Scene Segmentation, Linking And Attention Detection, Yun Zhai
Video Content Extraction: Scene Segmentation, Linking And Attention Detection, Yun Zhai
Electronic Theses and Dissertations
In this fast paced digital age, a vast amount of videos are produced every day, such as movies, TV programs, personal home videos, surveillance video, etc. This places a high demand for effective video data analysis and management techniques. In this dissertation, we have developed new techniques for segmentation, linking and understanding of video scenes. Firstly, we have developed a video scene segmentation framework that segments the video content into story units. Then, a linking method is designed to find the semantic correlation between video scenes/stories. Finally, to better understand the video content, we have developed a spatiotemporal attention detection …
Effects Of Atmospheric Turbulence On The Propagation Of Flattened Gaussian Optical Beams, Doris Cowan
Effects Of Atmospheric Turbulence On The Propagation Of Flattened Gaussian Optical Beams, Doris Cowan
Electronic Theses and Dissertations
In an attempt to mitigate the effects of the atmosphere on the coherence of an optical (laser) beam, interest has recently been shown in changing the beam shape to determine if a different power distribution at the transmitter will reduce the effects of the random fluctuations in the refractive index. Here, a model is developed for the field of a flattened Gaussian beam as it propagates through atmospheric turbulence, and the resulting effects upon the scintillation of the beam and upon beam wander are determined. A comparison of these results is made with the like effects on a standard TEM00 …
Algorithms For Discovering Communities In Complex Networks, Hemant Balakrishnan
Algorithms For Discovering Communities In Complex Networks, Hemant Balakrishnan
Electronic Theses and Dissertations
It has been observed that real-world random networks like the WWW, Internet, social networks, citation networks, etc., organize themselves into closely-knit groups that are locally dense and globally sparse. These closely-knit groups are termed communities. Nodes within a community are similar in some aspect. For example in a WWW network, communities might consist of web pages that share similar contents. Mining these communities facilitates better understanding of their evolution and topology, and is of great theoretical and commercial significance. Community related research has focused on two main problems: community discovery and community identification. Community discovery is the problem of extracting …
Fade Statistics For A Lasercom System And The Joint Pdf Of A Gamma-Gamma Distributed Irradiance And Its Time Derivative, Frida Stromqvist Vetelino
Fade Statistics For A Lasercom System And The Joint Pdf Of A Gamma-Gamma Distributed Irradiance And Its Time Derivative, Frida Stromqvist Vetelino
Electronic Theses and Dissertations
The performance of lasercom systems operating in the atmosphere is reduced by optical turbulence, which causes irradiance fluctuations in the received signal. The result is a randomly fading signal. Fade statistics for lasercom systems are determined from the probability density function (PDF) of the irradiance fluctuations. The expected number of fades per second and their mean fade time require the joint PDF of the fluctuating irradiance and its time derivative. Theoretical integral expressions, as well as closed form, analytical approximations, were developed for the joint PDF of a gamma-gamma distributed irradiance and its time derivative, and the corresponding expression for …
On Prime Generation Through Primitive Divisors Of Recurrence Sequences, Richard Russell
On Prime Generation Through Primitive Divisors Of Recurrence Sequences, Richard Russell
Electronic Theses and Dissertations
We examine results concerning the generation of primes in certain types of integer sequences. The sequences discussed all have a connection in that each satisfies a recurrence relation. Mathematicians have speculated over many centuries that these sequences contain an infinite number of prime terms, however no proof has been given as such. We examine a less direct method of showing an infinitude of primes in each sequence by showing that the sequences contain an infinite number of terms with primitive divisors.
Modeling And Characterizations Of New Notions In Life Testing With Statistical Applications, Mohammad Sepehrifar
Modeling And Characterizations Of New Notions In Life Testing With Statistical Applications, Mohammad Sepehrifar
Electronic Theses and Dissertations
Knowing the class to which a life distribution belongs gives us an idea about the aging of the device or system the life distribution represents, and enables us to compare the aging properties of different systems. This research intends to establish several new nonparametric classes of life distributions defined by the concept of inactivity time of a unit with a guaranteed minimum life length. These classes play an important role in the study of reliability theory, survival analysis, maintenance policies, economics, actuarial sciences and many other applied areas.
Modeling, Simulation, And Visualization Of 3d Lung Dynamics, Anand Santhanam
Modeling, Simulation, And Visualization Of 3d Lung Dynamics, Anand Santhanam
Electronic Theses and Dissertations
Medical simulation has facilitated the understanding of complex biological phenomenon through its inherent explanatory power. It is a critical component for planning clinical interventions and analyzing its effect on a human subject. The success of medical simulation is evidenced by the fact that over one third of all medical schools in the United States augment their teaching curricula using patient simulators. Medical simulators present combat medics and emergency providers with video-based descriptions of patient symptoms along with step-by-step instructions on clinical procedures that alleviate the patient's condition. Recent advances in clinical imaging technology have led to an effective medical visualization …
Noise Characerization For Proposed Ucf Phyiscal Science Building Sites., Jorge Martinez
Noise Characerization For Proposed Ucf Phyiscal Science Building Sites., Jorge Martinez
Electronic Theses and Dissertations
Today's Advance Technology Facilities require low noise levels and increased noise monitoring. Ambient noise can interfere with the accuracy and precision of experiments and manufacturing processes. Therefore preconstruction site surveys are needed to develop strategies for mitigating noise. Vibration and low frequency electromagnetic fields are particularly detrimental for sensitive instruments, and they are also difficult to mitigate. However a large part of these costs can be avoided or minimized if a quiet building site is selected in the first place. Accelerometers and gauss meters combined with a computer for acquisition and analysis provide a low cost method of evaluating noise …
Real-Time Monocular Vision-Based Tracking For Interactive Augmented Reality, Lisa Spencer
Real-Time Monocular Vision-Based Tracking For Interactive Augmented Reality, Lisa Spencer
Electronic Theses and Dissertations
The need for real-time video analysis is rapidly increasing in today's world. The decreasing cost of powerful processors and the proliferation of affordable cameras, combined with needs for security, methods for searching the growing collection of video data, and an appetite for high-tech entertainment, have produced an environment where video processing is utilized for a wide variety of applications. Tracking is an element in many of these applications, for purposes like detecting anomalous behavior, classifying video clips, and measuring athletic performance. In this dissertation we focus on augmented reality, but the methods and conclusions are applicable to a wide variety …
Syntax-Based Concept Extraction For Question Answering, Demetrios Glinos
Syntax-Based Concept Extraction For Question Answering, Demetrios Glinos
Electronic Theses and Dissertations
Question answering (QA) stands squarely along the path from document retrieval to text understanding. As an area of research interest, it serves as a proving ground where strategies for document processing, knowledge representation, question analysis, and answer extraction may be evaluated in real world information extraction contexts. The task is to go beyond the representation of text documents as "bags of words" or data blobs that can be scanned for keyword combinations and word collocations in the manner of internet search engines. Instead, the goal is to recognize and extract the semantic content of the text, and to organize it …
Fast Response Liquid Crystal Devices, Yung-Hsun Wu
Fast Response Liquid Crystal Devices, Yung-Hsun Wu
Electronic Theses and Dissertations
Liquid crystal (LC) has been widely used for displays, spatial light modulators, variable optical attenuators (VOAs) and other tunable photonic devices. The response time of these devices is mainly determined by the employed liquid crystal material. How to obtain fast response for the LC devices is a fundamentally important and technically challenging task. In this dissertation, we investigate several methods to improve liquid crystal response time, for examples, using dual-frequency liquid crystals, polymer stabilized liquid crystals, and sheared polymer network liquid crystals. We discover a new class of material, denoted as sheared polymer network liquid crystal (SPNLC) which exhibits a …
Collaboration Enforcement In Mobile Ad Hoc Networks, Ning Jiang
Collaboration Enforcement In Mobile Ad Hoc Networks, Ning Jiang
Electronic Theses and Dissertations
Mobile Ad hoc NETworks (MANETs) have attracted great research interest in recent years. Among many issues, lack of motivation for participating nodes to collaborate forms a major obstacle to the adoption of MANETs. Many contemporary collaboration enforcement techniques employ reputation mechanisms for nodes to avoid and penalize malicious participants. Reputation information is propagated among participants and updated based on complicated trust relationships to thwart false accusation of benign nodes. The aforementioned strategy suffers from low scalability and is likely to be exploited by adversaries. To address these problems, we first propose a finite state model. With this technique, no reputation …
Analysis Of Aircraft Arrival Delay And Airport On-Time Performance, Yuqiong Bai
Analysis Of Aircraft Arrival Delay And Airport On-Time Performance, Yuqiong Bai
Electronic Theses and Dissertations
While existing grid environments cater to specific needs of a particular user community, we need to go beyond them and consider general-purpose large-scale distributed systems consisting of large collections of heterogeneous computers and communication systems shared by a large user population with very diverse requirements. Coordination, matchmaking, and resource allocation are among the essential functions of large-scale distributed systems. Although deterministic approaches for coordination, matchmaking, and resource allocation have been well studied, they are not suitable for large-scale distributed systems due to the large-scale, the autonomy, and the dynamics of the systems. We have to seek for nondeterministic solutions for …
Direct Nonlinear Optics Measurements Of Raman Gain In Bulk Glasses And Estimates Of Fiber Performance, Robert Stegeman
Direct Nonlinear Optics Measurements Of Raman Gain In Bulk Glasses And Estimates Of Fiber Performance, Robert Stegeman
Electronic Theses and Dissertations
The need for more bandwidth in communications has stimulated the search for new fiberizable materials with properties superior to fused silica which is the current state-of-the-art. One of the key properties is Raman gain by which a pump beam amplifies a signal beam of longer wavelength. An apparatus capable of directly measuring the spectral dependence and absolute magnitude of the material Raman gain coefficient using nonlinear optics techniques has been built. Using radiation from a 1064 nm Nd:YAG laser as the pump and from a tunable Optical Parametric Generator and Amplifier as the signal, the Raman gain spectrum was measured …
Integrated Wavelength Stabilization Of Broad Area Semiconductor Lasers Using A Dual Grating Reflector, Jason O'Daniel
Integrated Wavelength Stabilization Of Broad Area Semiconductor Lasers Using A Dual Grating Reflector, Jason O'Daniel
Electronic Theses and Dissertations
A new fully integrated wavelength stabilization scheme based on grating-coupled surface-emitting lasers is explored. This wavelength stabilization scheme relies on two gratings. The first grating is fabricated on the p-side of the semiconductor laser in close proximity to the laser waveguide such that it couples light out of the guided mode of the waveguide into a propagating mode in the substrate; this grating is known as the grating coupler. The second grating is fabricated on the n-side of the substrate such that for the stabilization wavelength, this second grating operates in the Littrow condition and is known as the feedback …
Propagation Effect In Inhomogeneous Media, Including Media With Light-Induced And Fixed Gratings, Chang-Ching Tsai
Propagation Effect In Inhomogeneous Media, Including Media With Light-Induced And Fixed Gratings, Chang-Ching Tsai
Electronic Theses and Dissertations
Optical waves propagation in various types of volume gratings, materials with constant impendence and optical fibers are studied. Instability of crossphase modulation and of Energy transfer via GRON-type (Grating-type Orientational Nonlinearity in Liquid Crystal) Stimulated Scattering is numerically observed. Two diffractive optical elements made of volume gratings are suggested and analyzed. A transmission hologram based on the analogy with Stimulated Raman Adiabatic Passage (STIRAP) in nonlinear optics is proposed. This transmission hologram demonstrates high diffraction efficiency and low sensitivity to polarization and hologram strength. The other is a reflection hologram with two crossed-gratings. It features good angular selectivity in comparison …
Effect Of Germanium Doping On Erbium Sensitization In The Erbium Doped Silicon Rich Silica Material System, Forrest Ruhge
Effect Of Germanium Doping On Erbium Sensitization In The Erbium Doped Silicon Rich Silica Material System, Forrest Ruhge
Electronic Theses and Dissertations
The continued size reduction in electronic integrated circuits has lead to a demand for on-chip high-bandwidth and low loss communication channels. Optical interconnects are considered an essential addition to the silicon electronics platform. A major challenge in the field of integrated Si photonics is the development of cost effective silicon compatible light sources. This thesis investigates the sensitization of group IV doped silica films emitting at 1.535μm for applications as silicon compatible light sources. Thin erbium-doped silica films containing excess silicon and germanium were deposited using a multi-gun sputter system. The composition of the deposited materials was verified by Rutherford …
Molecular Structure-Nonlinear Optical Property Relationships For A Series Of Polymethine And Squaraine Molecules, Jie Fu
Electronic Theses and Dissertations
This dissertation reports on the investigation of the relationships between molecular structure and two-photon absorption (2PA) properties for a series of polymethine and squaraine molecules. Current and emerging applications exploiting the quadratic dependence upon laser intensity, such as two-photon fluorescence imaging, three-dimensional microfabrication, optical data storage and optical limiting, have motivated researchers to find novel materials exhibiting strong 2PA. Organic materials are promising candidates because their linear and nonlinear optical properties can be optimized for applications by changing their structures through molecular engineering. Polymethine and squaraine dyes are particularly interesting because they are fluorescent and showing large 2PA. We used …
Three-Photon Absorption Process In Organic Dyes Enhanced By Surface Plasmon Resonance, Ion Cohanoschi
Three-Photon Absorption Process In Organic Dyes Enhanced By Surface Plasmon Resonance, Ion Cohanoschi
Electronic Theses and Dissertations
Multi-photon absorption processes have received significant attention from the scientific community during the last decade, mainly because of their potential applications in optical limiting, data storage and biomedical fields. Perhaps, one of the most investigated processes studied so far has been two-photon absorption (2PA). These investigations have resulted in successful applications in all the fields mentioned above. However, 2PA present some limitations in the biomedical field when pumping at typical 2PA wavelengths. In order to overcome these limitations, three-photon absorption (3PA) process has been proposed. However, 3PA in organic molecules has a disadvantage, typical values of σ3' are small (10-81 …
Applications Of Linear And Nonlinear Optical Effects In Liquid Crystals, Hakob Sarkissian
Applications Of Linear And Nonlinear Optical Effects In Liquid Crystals, Hakob Sarkissian
Electronic Theses and Dissertations
Liquid crystals have been a major subject of research for the past decades. Aside from the variety of structures they can form, they exhibit a vast range of optical phenomena. Many of these phenomena found applications in technology and became an essential part of it. In this dissertation thesis we continue the line to propose a number of new applications of optical effects in liquid crystals and develop their theoretical framework. One such application is the possibility of beam combining using Orientational Stimulated Scattering in a nematic liquid crystal cell. Our numerical study of the OSS process shows that normally …