Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Theses and Dissertations

Discipline
Institution
Keyword
Publication Year
File Type

Articles 1681 - 1710 of 2733

Full-Text Articles in Computer Sciences

Framework To Secure Cloud-Based Medical Image Storage And Management System Communications, Timothy James Rostrom Dec 2011

Framework To Secure Cloud-Based Medical Image Storage And Management System Communications, Timothy James Rostrom

Theses and Dissertations

Picture Archiving and Communication Systems (PACS) have been traditionally constrained to the premises of the healthcare provider. This has limited the availability of these systems in many parts of the world and mandated major costs in infrastructure for those who employ them. Public cloud services could be a solution that eases the cost of ownership and provides greater flexibility for PACS implementations. This could make it possible to bring medical imaging services to places where it was previously unavailable and reduce the costs associated with these services for those who utilize them. Moving these systems to public cloud infrastructure requires …

Go to article

A Hierarchical Image Processing Approach For Diagnostic Analysis Of Microcirculation Videos, Nazanin Mirshahi Dec 2011

A Hierarchical Image Processing Approach For Diagnostic Analysis Of Microcirculation Videos, Nazanin Mirshahi

Theses and Dissertations

Knowledge of the microcirculatory system has added significant value to the analysis of tissue oxygenation and perfusion. While developments in videomicroscopy technology have enabled medical researchers and physicians to observe the microvascular system, the available software tools are limited in their capabilities to determine quantitative features of microcirculation, either automatically or accurately. In particular, microvessel density has been a critical diagnostic measure in evaluating disease progression and a prognostic indicator in various clinical conditions. As a result, automated analysis of the microcirculatory system can be substantially beneficial in various real-time and off-line therapeutic medical applications, such as optimization of resuscitation. …

Go to article

Quality Selection For Dynamic Adaptive Streaming Over Http With Scalable Video Coding, Travis L. Andelin Dec 2011

Quality Selection For Dynamic Adaptive Streaming Over Http With Scalable Video Coding, Travis L. Andelin

Theses and Dissertations

Video streaming on the Internet is increasingly using Dynamic Adaptive Streaming over HTTP (DASH), in which the video is converted into various quality levels and divided into two-second segments. A client can then adjust its video quality over time by choosing to download the appropriate quality level for a given segment using standard HTTP. Scalable Video Coding (SVC) is a promising enhancement to the DASH protocol. With SVC, segments are divided into subset bitstream blocks. At playback, blocks received for a given segment are combined to additively increase the current quality. Unlike traditional DASH, which downloads segments serially, this encoding …

Go to article

Fast Parallel Machine Learning Algorithms For Large Datasets Using Graphic Processing Unit, Qi Li Nov 2011

Fast Parallel Machine Learning Algorithms For Large Datasets Using Graphic Processing Unit, Qi Li

Theses and Dissertations

This dissertation deals with developing parallel processing algorithms for Graphic Processing Unit (GPU) in order to solve machine learning problems for large datasets. In particular, it contributes to the development of fast GPU based algorithms for calculating distance (i.e. similarity, affinity, closeness) matrix. It also presents the algorithm and implementation of a fast parallel Support Vector Machine (SVM) using GPU. These application tools are developed using Compute Unified Device Architecture (CUDA), which is a popular software framework for General Purpose Computing using GPU (GPGPU). Distance calculation is the core part of all machine learning algorithms because the closer the query …

Go to article

Fast Spheroidal Weathering With Colluvium Deposition, Mckay T. Farley Nov 2011

Fast Spheroidal Weathering With Colluvium Deposition, Mckay T. Farley

Theses and Dissertations

It can be difficult to quickly and easily create realistic sandstone terrain. Film makers often need to generate realistic terrain for establishing the setting of their film. Many methods have been created which address terrain generation. One such method is using heightmaps which encode height as a gray-value in a 2d image. Most terrain generation techniques don't admit concavities such as overhangs and arches. We present an algorithm that operates on a voxel grid for creating 3d terrain. Our algorithm uses curvature estimation to weather away the terrain. We speed up our method using a caching mechanism that stores the …

Go to article

Carry And Expand: A New Nomadic Interaction Paradigm, Richard B. Arthur Nov 2011

Carry And Expand: A New Nomadic Interaction Paradigm, Richard B. Arthur

Theses and Dissertations

People are nomadic; traveling from place to place. As a user travels, he may need access to his digital information, including his data, applications, and settings. A convenient way to supply this access is to have the user carry that digital information in a portable computer such as a laptop or smart phone. As Moore's Law continues to operate, devices such as smart phones can easily perform the computing necessary for a user's work. Unfortunately, the amount of data a human can receive and convey through such devices is limited. To receive more information humans require more screen real estate. …

Go to article

A Foveated System For Wilderness Search And Rescue In Manned Aircraft, Carson D. Fenimore Nov 2011

A Foveated System For Wilderness Search And Rescue In Manned Aircraft, Carson D. Fenimore

Theses and Dissertations

Wilderness search and rescue can be assisted by video searchers in manned aircraft. The video searcher's primary task is to find clues on the ground. Due to altitude, it may be difficult to resolve details on the ground with a standard video camera. As the video streams at a constant frame rate, the searcher may become distracted by other tasks. While handling these tasks the searcher may miss important clues or spend extra time flying over the search area; either outcome decreases both the effectiveness of the video searcher and the chances of successfully finding missing persons. We develop an …

Go to article

Modeling And Designing Fair Rate Control For Wireless Mesh Networks With Partial Interference, Lei Wang Nov 2011

Modeling And Designing Fair Rate Control For Wireless Mesh Networks With Partial Interference, Lei Wang

Theses and Dissertations

Internet rate control protocols, such as TCP, encounter severe performance problems in wireless mesh networks. Because wireless networks use shared communication channels, contention and interference can significantly degrade flow throughput and fairness. Existing research takes either an engineering-based or optimization-based approach to solve the performance problems. The engineering-based approach usually solves a specific observed problem, but does not necessarily optimize the overall performance. The optimization-based approach mathematically models the network to find the optimal resource allocation among competing flows. The model can lead to a distributed rate control algorithm with performance guarantees, but relatively little work has been done to …

Go to article

Improving Multi-Label Classification By Avoiding Implicit Negativity With Incomplete Data, Derrall L. Heath Oct 2011

Improving Multi-Label Classification By Avoiding Implicit Negativity With Incomplete Data, Derrall L. Heath

Theses and Dissertations

Many real world problems require multi-label classification, in which each training instance is associated with a set of labels. There are many existing learning algorithms for multi-label classification; however, these algorithms assume implicit negativity, where missing labels in the training data are automatically assumed to be negative. Additionally, many of the existing algorithms do not handle incremental learning in which new labels could be encountered later in the learning process. A novel multi-label adaptation of the backpropagation algorithm is proposed that does not assume implicit negativity. In addition, this algorithm can, using a naive Bayesian approach, infer missing labels in …

Go to article

A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube Sep 2011

A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube

Theses and Dissertations

The rapid transition of critical business processes to computer networks potentially exposes organizations to digital theft or corruption by advanced competitors. One tool used for these tasks is malware, because it circumvents legitimate authentication mechanisms. Malware is an epidemic problem for organizations of all types. This research proposes and evaluates a novel Malware Target Recognition (MaTR) architecture for malware detection and identification of propagation methods and payloads to enhance situation awareness in tactical scenarios using non-instruction-based, static heuristic features. MaTR achieves a 99.92% detection accuracy on known malware with false positive and false negative rates of 8.73e-4 and 8.03e-4 respectively. …

Go to article

An Empirical Analysis Of The Cascade Secret Key Reconciliation Protocol For Quantum Key Distribution, Timothy I. Calver Sep 2011

An Empirical Analysis Of The Cascade Secret Key Reconciliation Protocol For Quantum Key Distribution, Timothy I. Calver

Theses and Dissertations

The need to share key material with authorized entities in a secure, efficient and timely manner has driven efforts to develop new key distribution methods. The most promising method is Quantum Key Distribution (QKD) and is considered to be “unconditionally secure” because it relies upon the immutable laws of quantum physics rather than computational complexity. Unfortunately, the nonidealities present in actual implementations of QKD systems also result in errors manifested in the quantum data channel. As a consequence, an important component of any QKD system is the error reconciliation protocol which is used to identify and correct inconsistencies in the …

Go to article

Detecting Man-In-The-Middle Attacks Against Transport Layer Security Connections With Timing Analysis, Lauren M. Wagoner Sep 2011

Detecting Man-In-The-Middle Attacks Against Transport Layer Security Connections With Timing Analysis, Lauren M. Wagoner

Theses and Dissertations

The Transport Layer Security (TLS) protocol is a vital component to the protection of data as it traverses across networks. From e-commerce websites to Virtual Private Networks (VPNs), TLS protects massive amounts of private information, and protecting this data from Man-in-the-Middle (MitM) attacks is imperative to keeping the information secure. This thesis illustrates how an attacker can successfully perform a MitM attack against a TLS connection without alerting the user to his activities. By deceiving the client machine into using a false certificate, an attacker takes away the only active defense mechanism a user has against a MitM. The goal …

Go to article

Security In Intranet And Vpn, Sami Kryeziu Sep 2011

Security In Intranet And Vpn, Sami Kryeziu

Theses and Dissertations

Që nga vitet `70 kur edhe janë vitet e para të internetit që është zbuluar nga ARPANET ku në rrjet numronin katër kompjuter deri në ditët e sotëshme ku numërohen me miliarda përdorues qështja më e ndjeshme ka qenë siguria e këtij rrjeti. Në vitet e fundit ndërthuarja në mes të teknologjis informative dhe bizneseve si dhe mënyra se si të ulen kostot buxhetore duke ju mënjanuar teknologjive të kushtueshme bëri që VPN të jet njëra ndër teknologjit e qëlluara. Virtual Private Network është një teknologji që lindi duke e pasur parasysh nevojën e një komunikimi që ofron siguri të …

Go to article

Jigdfs: The Jigsaw Secure Distributed File System And Its Applications, Jiang Bian Aug 2011

Jigdfs: The Jigsaw Secure Distributed File System And Its Applications, Jiang Bian

Theses and Dissertations

The Jigsaw Distributed File System (JigDFS) aims to securely store and retrieve files on large scale networks. While targeting many of the same goals as previous distributed file systems, the design of JigDFS is mainly driven by the privacy needs of users. Files in JigDFS are sliced into small segments using an Information Dispersal Algorithm (IDA) and distributed onto different nodes recursively to increase fault tolerance against node failures. Layered encryption is applied to each file segment with keys produced by a hashed-key chain algorithm, so that encrypted data and keys are stored separately. Recursive IDA and layered encryption enhance …

Go to article

A Data-Intensive Approach To Named Entity Recognition Using Domain And Language Independent Methods, Olukayode Isaac Osesina Aug 2011

A Data-Intensive Approach To Named Entity Recognition Using Domain And Language Independent Methods, Olukayode Isaac Osesina

Theses and Dissertations

In this dissertation, I proposed a novel approach to Named Entity Recognition (NER) in which the contextual and intrinsic indicators are used for locating named entities and their semantic meanings in unstructured textual information (UTI). Named entity is the process of locating a word or a phrase that references a particular entity within a text. The data-intensive approach introduced in this dissertation departs from the traditional Natural Language Processing used in NER tasks in that it does not apply linguistic rules or knowledge in the entity recognition process. It leverages the wide availability of huge amounts of data as well …

Go to article

Simulation Of Mobile Treatment Monitoring System, Emre Ermisoglu Aug 2011

Simulation Of Mobile Treatment Monitoring System, Emre Ermisoglu

Theses and Dissertations

Noncompliance is the main reason for treatment failure. Approximately 50 to 75% of patients misuse their medication due to forgetfulness and busy schedule. Instead of heavily depending on patient's memory for following medication deadlines, we propose a new automated medication helper called "Mobile Treatment Monitoring System" to help patients take their medication on time. Among other technologies that help patients to follow up their medication such as Pill Organizers, Medication Reminders, and Pill Dispensers, using remote treatment monitoring system appears to be a promising technology because system creates a direct link between doctor and patient so doctor will be notified …

Go to article

Energy-Efficient And Secure Framework For Wireless Sensor Networks, Murat Al Aug 2011

Energy-Efficient And Secure Framework For Wireless Sensor Networks, Murat Al

Theses and Dissertations

Protocol designers for wireless sensor networks (WSNs) have to consider many constraints including limited power and computing capacity of the sensing devices that make WSNs more vulnerable to attacks than wired or more resourceful wireless networks. The availability of a message for the adversary is the starting point for attacks on data confidentiality. This work proposes an end-to-end Message Dispersion Mechanism (MDM) to improve data confidentiality by significantly reducing message interception opportunities by potential adversaries in the first place. With MDM, a resource constrained sensor device first divides a message into several segments, encrypts them, and distributes them to a …

Go to article

Object & Scene Recognition Using Color Descriptors And Adaptive Color Klt, Volkan Halil Bagci Aug 2011

Object & Scene Recognition Using Color Descriptors And Adaptive Color Klt, Volkan Halil Bagci

Theses and Dissertations

With the emergence and explosion of huge image databases there is an increasing necessity for effective methods to assess visual information on the level of objects and scene types. A wide variety of Content - Based Image Retrieval (CBIR) systems already exists. As a key issue in CBIR, similarity measure quantifies the resemblance in contents between a pair of images. Depending on the type of features, the formulation of the similarity measure varies greatly. The primary goal of our study is to build a CBIR system based on color features using Adaptive Color Karhunen Loeve Transform (ACKLT) which is efficient …

Go to article

Knowledge Discovery In Fetal Activity Data, Dallas H. Snider Aug 2011

Knowledge Discovery In Fetal Activity Data, Dallas H. Snider

Theses and Dissertations

The ability to determine accurately the health of a fetus through non-invasive techniques has tremendous positive affects for the fetus, the mother, and the health care system. In this project, Knowledge Discovery in Databases (KDD) techniques were applied to fetal magnetocardiogram data from 118 human fetuses with a gestational age of 24 to 39 weeks. These techniques produced three models relating to the health of a fetus which are presented in this document. The first model distinguished maternal high-risk factors versus low-risk factors. The second model was used to classify neonate outcomes of sick versus healthy. The third model was …

Go to article

Modeling And Simulation Of Hpc System Through Job Scheduling Analysis, William Bradley Hurst Aug 2011

Modeling And Simulation Of Hpc System Through Job Scheduling Analysis, William Bradley Hurst

Theses and Dissertations

The sophistication of the devices through which a man shapes his world are the tool-marks of his development upon history. One device currently shaping the lives of man is the High Performance Computer (HPC) system. HPC systems have been described as ``a game changing technology (King and BusinessWeek, 2010).'' The reason for HPC systems to be declared ``a game changing technology (King and BusinessWeek, 2010)'' comes from the fact that it is cheaper for a manufacturer to conduct thousands of tests in virtual space, than it is to try multiple experimental designs in the physical world. Through capabilities of HPC …

Go to article

Hykss: Hybrid Keyword And Semantic Search, Andrew J. Zitzelberger Aug 2011

Hykss: Hybrid Keyword And Semantic Search, Andrew J. Zitzelberger

Theses and Dissertations

The rapid production of digital information makes the task of locating relevant information increasingly difficult. Keyword search alleviates this difficulty by retrieving documents containing keywords of interest. However, keyword search suffers from a number of issues such ambiguity, synonymy, and the inability to handle semantic constraints. Semantic search helps resolve these issues but is limited by the quality of annotations which are likely to be incomplete or imprecise. Hybrid search, a search technique that combines the merits of both keyword and semantic search, appears to be a promising solution. In this work we introduce HyKSS, a hybrid search system driven …

Go to article

Modelimi I Kërcënimeve Sipas Teknikës Microsoft Threat Modeling, Naim Preniqi Aug 2011

Modelimi I Kërcënimeve Sipas Teknikës Microsoft Threat Modeling, Naim Preniqi

Theses and Dissertations

Modelimi i kërcënimeve është qasje e strukturuar që ka të bëjë me analizimin, identifikimin, përmbledhjen dhe adresimin e çështjeve të sigurisë, të cilat janë të ndërlidhura ngushtë me aplikacionin. Modelimi i kërcënimeve nuk shqyrton vetëm kodimin, por më tepër merret me vlerësimin dhe shqyrtimin e procesit të kodimit. Adresimi i kërcënimeve mund të bëhet me kundërmasat adekuate në mënyrë logjike, duke u nisur nga kërcënimet që paraqesin më së shumti rrezik. Një gjë e tillë bëhet duke identifikuar dhe vlerësuar kërcënimet e bazuara kushtimisht, dhe duke e kuptuar sistemin arkitektural dhe implementimin e aplikacionit. Modelimi i kërcënimeve ka një qasje …

Go to article

Fast Relabeling Of Deformable Delaunay Tetrahedral Meshes Using A Compact Uniform Grid, David C. Frogley Jul 2011

Fast Relabeling Of Deformable Delaunay Tetrahedral Meshes Using A Compact Uniform Grid, David C. Frogley

Theses and Dissertations

We address the problem of fast relabeling of deformable Delaunay tetrahedral meshes using a compact uniform grid, with CPU parallelization through OpenMP. This problem is important in visualizing the simulation of deformable objects and arises in scientific visualization, games, computer vision, and motion picture production. Many existing software tools and APIs have the ability to manipulate 3D virtual objects. Prior mesh-based representations either allow topology changes or are fast. We aim for both. Specifically, we improve the efficiency of the relabeling step in the Delaunay deformable mesh invented by Pons and Boissonnat and improved by Tychonievich and Jones. The relabeling …

Go to article

Modeling Wireless Networks For Rate Control, David C. Ripplinger Jul 2011

Modeling Wireless Networks For Rate Control, David C. Ripplinger

Theses and Dissertations

Congestion control algorithms for wireless networks are often designed based on a model of the wireless network and its corresponding network utility maximization (NUM) problem. The NUM problem is important to researchers and industry because the wireless medium is a scarce resource, and currently operating protocols such as 802.11 often result in extremely unfair allocation of data rates. The NUM approach offers a systematic framework to build rate control protocols that guarantee fair, optimal rates. However, classical models used with the NUM approach do not incorporate partial carrier sensing and interference, which can lead to significantly suboptimal performance when actually …

Go to article

Naive Bayesian Spam Filters For Log File Analysis, Russel William Havens Jul 2011

Naive Bayesian Spam Filters For Log File Analysis, Russel William Havens

Theses and Dissertations

As computer system usage grows in our world, system administrators need better visibility into the workings of computer systems, especially when those systems have problems or go down. Most system components, from hardware, through OS, to application server and application, write log files of some sort, be it system-standardized logs such syslog or application specific logs. These logs very often contain valuable clues to the nature of system problems and outages, but their verbosity can make them difficult to utilize. Statistical data mining methods could help in filtering and classifying log entries, but these tools are often out of the …

Go to article

Experimental Performance Evaluation Of Atp (Ad-Hoc Transport Protocol) In A Wireless Mesh Network, Xingang Zhang Jun 2011

Experimental Performance Evaluation Of Atp (Ad-Hoc Transport Protocol) In A Wireless Mesh Network, Xingang Zhang

Theses and Dissertations

It is well known that TCP performs poorly in wireless mesh networks. There has been intensive research in this area, but most work uses simulation as the only evaluation method; however, it is not clear whether the performance gains seen with simulation will translate into benefits on real networks. To explore this issue, we have implemented ATP (Ad-hoc Transport Protocol), a transport protocol designed specifically for wireless ad hoc networks. We have chosen ATP because it uses a radically different design from TCP and because reported results claim significant improvement over TCP. We show how ATP must be modified in …

Go to article

Rendering Realistic Cloud Effects For Computer Generated Films, Cory A. Reimschussel Jun 2011

Rendering Realistic Cloud Effects For Computer Generated Films, Cory A. Reimschussel

Theses and Dissertations

This work addresses the problem of rendering clouds. The task of rendering clouds is important to film and video game directors who want to use clouds to further the story or create a specific atmosphere for the audience. While there has been significant progress in this area, other solutions to this problem are inadequate because they focus on speed instead of accuracy, or focus only on a few specific properties of rendered clouds while ignoring others. Another common shortcoming with other methods is that they are not integrated into existing rendering pipelines. We propose a solution to this problem based …

Go to article

A Study Analyzing Five Instructional Methods For Teaching Software To Junior High Students, Scott Ronald Bartholomew Jun 2011

A Study Analyzing Five Instructional Methods For Teaching Software To Junior High Students, Scott Ronald Bartholomew

Theses and Dissertations

If you ask 5 different teachers what the best way to teach a new technology to a student is you will get 5 different answers. (Bork, 2001; Cheong, 2008; Egal, 2009; Howell, 2001) What is the best way to teach a new computer software application to a student? In the technological world we live in today the effective transfer of technological knowledge is paramount. With varying opinions even among the leaders of national technology teacher associations (Haynie, 2005) there is a large level of ambiguity in relation to best practices in technology teaching. This study evaluates five commonly used methods …

Go to article

Combinational Circuit Obfuscation Through Power Signature Manipulation, Hyunchul Ko Jun 2011

Combinational Circuit Obfuscation Through Power Signature Manipulation, Hyunchul Ko

Theses and Dissertations

Today's military systems are composed of hardware and software systems, many of which are critical technologies, and must be protected to ensure our adversaries cannot gain any information from a various analysis attacks. Side Channel Analysis (SCA) attacks allow an attacker to gain the significant information from the measured signatures leaked by side-channels such as power consumption, and electro-magnetic emission. In this research the focus on detecting, characterizing, and manipulating the power signature by designing a power signature estimation and manipulation method. This research has determined that the proposed method capable of characterizing and altering the type of power signature …

Go to article

Estimating Anthropometric Marker Locations From 3-D Ladar Point Clouds, Matthew J. Maier Jun 2011

Estimating Anthropometric Marker Locations From 3-D Ladar Point Clouds, Matthew J. Maier

Theses and Dissertations

An area of interest for improving the identification portion of the system is in extracting anthropometric markers from a Laser Detection and Ranging (LADAR) point cloud. Analyzing anthropometrics markers is a common means of studying how a human moves and has been shown to provide good results in determining certain demographic information about the subject. This research examines a marker extraction method utilizing principal component analysis (PCA), self-organizing maps (SOM), alpha hulls, and basic anthropometric knowledge. The performance of the extraction algorithm is tested by performing gender classification with the calculated markers.

Go to article

First Prev Next Last