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Full-Text Articles in Physical Sciences and Mathematics

A Time Series Analysis Method Using Hidden Variables For Gene Network Reconstruction, Xi Wu Dec 2012

A Time Series Analysis Method Using Hidden Variables For Gene Network Reconstruction, Xi Wu

Dissertations

The DNA microarray technology can be applied to obtain time series data which contains thousands of genes and tens of time points. When confront the great amount of data points a fast and effective method must be constructed to extract useful information. The assumption that the interactions between genes are static in the time series data is made. After made the assumption how to reconstruct those interactions becomes a difficulty problem. Since the underlying interactions between genes are complicated, which involve transcription, translation and protein-protein interaction, to construct a model from physicochemistry is almost impossible/effortless. The popular methods constructed from …


Rule-Based Precise Localization Services In Mobile Environments, Mohammed Elbes Dec 2012

Rule-Based Precise Localization Services In Mobile Environments, Mohammed Elbes

Dissertations

In recent years there has been great interest in the positioning of people and assets in indoor and outdoor environments. Many systems were constructed to accomplish this. The application of these systems depends on the environment and the precision required for localization. The Global Positioning System (GPS) cannot be used for a precise indoor localization due to the attenuation and scattering of the signals. For indoor environments, other technologies like Wireless LAN, laser, camera images and motion sensors are used in precise localization. GPS can be used in outdoor environments but if localization accuracy is a critical requirement, other technologies …


Reification: A Process To Configure Java Realtime Processors, John Huddleston Heath Dec 2012

Reification: A Process To Configure Java Realtime Processors, John Huddleston Heath

Dissertations

Real-time systems require stringent requirements both on the processor and the software application. The primary concern is speed and the predictability of execution times. In all real-time applications the developer must identify and calculate the worst case execution times (WCET) of their software. In almost all cases the processor design complexity impacts the analysis when calculating the WCET. Design features which impact this analysis include cache and instruction pipelining. With both cache and pipelining the time taken for a particular instruction can vary depending on cache and pipeline contents. When calculating the WCET the developer must ignore the speed advantages …


Adaptive Security-Aware Scheduling For Packet Switched Networks Using Real-Time Multi-Agent Systems, Ma'en Saleh Saleh Jun 2012

Adaptive Security-Aware Scheduling For Packet Switched Networks Using Real-Time Multi-Agent Systems, Ma'en Saleh Saleh

Dissertations

Conventional real-time scheduling algorithms are in care of timing constraints; they don’t pay any attention to enhance or optimize the real-time packet’s security performance. In this work, we propose an adaptive security-aware scheduling with congestion control mechanism for packet switching networks using real-time agentbased systems. The proposed system combines the functionality of real-time scheduling with the security service enhancement, where the real-time scheduling unit uses the differentiated-earliest-deadline-first (Diff-EDF) scheduler, while the security service enhancement scheme adopts a congestion control mechanism based on a resource estimation methodology.

The security service enhancement unit was designed based on two models: singlelayer and weighted …


Structural Analysis And Auditing Of Snomed Hierarchies Using Abstraction Networks, Yue Wang May 2012

Structural Analysis And Auditing Of Snomed Hierarchies Using Abstraction Networks, Yue Wang

Dissertations

SNOMED is one of the leading healthcare terminologies being used worldwide. Due to its sheer volume and continuing expansion, it is inevitable that errors will make their way into SNOMED. Thus, quality assurance is an important part of its maintenance cycle.

A structural approach is presented in this dissertation, aiming at developing automated techniques that can aid auditors in the discovery of terminology errors more effectively and efficiently. Large SNOMED hierarchies are partitioned, based primarily on their relationships patterns, into concept groups of more manageable sizes. Three related abstraction networks with respect to a SNOMED hierarchy, namely the area taxonomy …


Effects Of Information Importance And Distribution On Information Exchange In Team Decision Making, Babajide James Osatuyi May 2012

Effects Of Information Importance And Distribution On Information Exchange In Team Decision Making, Babajide James Osatuyi

Dissertations

Teams in organizations are strategically built with members from domains and experiences so that a wider range of information and options can be pooled. This strategic team structure is based on the assumption that when team members share the information they have, the team as a whole can access a larger pool of information than any one member acting alone, potentially enabling them to make better decisions. However, studies have shown that teams, unlike individuals, sometimes do not effectively share and use the unique information available to them, leading to poorer decisions. Research on information sharing in team decision making …


Registration And Categorization Of Camera Captured Documents, Venkata Gopal Edupuganti May 2012

Registration And Categorization Of Camera Captured Documents, Venkata Gopal Edupuganti

Dissertations

Camera captured document image analysis concerns with processing of documents captured with hand-held sensors, smart phones, or other capturing devices using advanced image processing, computer vision, pattern recognition, and machine learning techniques. As there is no constrained capturing in the real world, the captured documents suffer from illumination variation, viewpoint variation, highly variable scale/resolution, background clutter, occlusion, and non-rigid deformations e.g., folds and crumples. Document registration is a problem where the image of a template document whose layout is known is registered with a test document image. Literature in camera captured document mosaicing addressed the registration of captured documents with …


Example Based Texture Synthesis And Quantification Of Texture Quality, Chandralekha De May 2012

Example Based Texture Synthesis And Quantification Of Texture Quality, Chandralekha De

Dissertations

Textures have been used effectively to create realistic environments for virtual worlds by reproducing the surface appearances. One of the widely-used methods for creating textures is the example based texture synthesis method. In this method of generating a texture of arbitrary size, an input image from the real world is provided. This input image is used for the basis of generating large textures. Various methods based on the underlying pattern of the image have been used to create these textures; however, the problem of finding an algorithm which provides a good output is still an open research issue. Moreover, the …


Error Estimation Techniques To Refine Overlapping Aerial Image Mosaic Processes Via Detected Parameters, William Glenn Bond May 2012

Error Estimation Techniques To Refine Overlapping Aerial Image Mosaic Processes Via Detected Parameters, William Glenn Bond

Dissertations

In this paper, I propose to demonstrate a means of error estimation preprocessing in the assembly of overlapping aerial image mosaics. The mosaic program automatically assembles several hundred aerial images from a data set by aligning them, via image registration using a pattern search method, onto a GIS grid.

The method presented first locates the images from a data set that it predicts will not align well via the mosaic process, then it uses a correlation function, optimized by a modified Hooke and Jeeves algorithm, to provide a more optimal transformation function input to the mosaic program. Using this improved …


Adaptive Radial Basis Function Neural Networks-Based Real Time Harmonics Estimation And Pwm Control For Active Power Filters, Eyad Kh Almaita Apr 2012

Adaptive Radial Basis Function Neural Networks-Based Real Time Harmonics Estimation And Pwm Control For Active Power Filters, Eyad Kh Almaita

Dissertations

With the proliferation of nonlinear loads in the power system, harmonic pollution becomes a serious problem that affects the power quality in both transmission and distribution systems. Active power filters (APF) have been proven to be one of the most successful methods for mitigating harmonics problems. So far, different techniques have been used in harmonics extraction and control of APF to satisfy the fast response and the accuracy required by the APF. Neural networks techniques have been used successfully in different real-time and complex situations. This dissertation demonstrates four main tasks; (i) a novel adaptive radial basis function neural networks …


Efficient Reinforcement Learning In Multiple-Agent Systems And Its Application In Cognitive Radio Networks, Jing Zhang Apr 2012

Efficient Reinforcement Learning In Multiple-Agent Systems And Its Application In Cognitive Radio Networks, Jing Zhang

Dissertations

The objective of reinforcement learning in multiple-agent systems is to find an efficient learning method for the agents to behave optimally. Finding Nash equilibrium has become the common learning target for the optimality. However, finding Nash equilibrium is a PPAD (Polynomial Parity Arguments on Directed graphs)-complete problem. The conventional methods can find Nash equilibrium for some special types of Markov games.

This dissertation proposes a new reinforcement learning algorithm to improve the search efficiency and effectiveness for multiple-agent systems. This algorithm is based on the definition of Nash equilibrium and utilizes the greedy and rational features of the agents. When …


Using An Ontology To Improve The Web Search Experience, Tian Tian Jan 2012

Using An Ontology To Improve The Web Search Experience, Tian Tian

Dissertations

The search terms that a user passes to a search engine are often ambiguous, referring to homonyms. The results in these cases are a mixture of links to documents that contain different meanings of the search terms. Current search engines provide suggested query completions in a dropdown list. However, such lists are not well organized, mixing completions for different meanings. In addition, the suggested search phrases are not discriminating enough. Moreover, current search engines often return an unexpected number of results. Zero hits are naturally undesirable, while too many hits are likely to be overwhelming and of low precision.

This …


Design And Implementation Of A Cyberinfrastructure For Rna Motif Search, Prediction And Analysis, Dongrong Wen Jan 2012

Design And Implementation Of A Cyberinfrastructure For Rna Motif Search, Prediction And Analysis, Dongrong Wen

Dissertations

RNA secondary and tertiary structure motifs play important roles in cells. However, very few web servers are available for RNA motif search and prediction. In this dissertation, a cyberinfrastructure, named RNAcyber, capable of performing RNA motif search and prediction, is proposed, designed and implemented.

The first component of RNAcyber is a web-based search engine, named RmotifDB. This web-based tool integrates an RNA secondary structure comparison algorithm with the secondary structure motifs stored in the Rfam database. With a user-friendly interface, RmotifDB provides the ability to search for ncRNA structure motifs in both structural and sequential ways. The second component of …


Approximate String Matching Methods For Duplicate Detection And Clustering Tasks, Oleksandr Rudniy Jan 2012

Approximate String Matching Methods For Duplicate Detection And Clustering Tasks, Oleksandr Rudniy

Dissertations

Approximate string matching methods are utilized by a vast number of duplicate detection and clustering applications in various knowledge domains. The application area is expected to grow due to the recent significant increase in the amount of digital data and knowledge sources. Despite the large number of existing string similarity metrics, there is a need for more precise approximate string matching methods to improve the efficiency of computer-driven data processing, thus decreasing labor-intensive human involvement.

This work introduces a family of novel string similarity methods, which outperform a number of effective well-known and widely used string similarity functions. The new …