Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Computer networks--Security measures (5)
- Machine learning (5)
- Computer security (3)
- Image segmentation (3)
- #antcenter (2)
-
- 3-manifolds (2)
- Artificial intelligence (2)
- Artificial satellites--Orbits--Mathematical models (2)
- Atmospheric turbulence (2)
- Bayesian (2)
- Cesium (2)
- Chemistry (2)
- Classification (2)
- Database (2)
- Decision making (2)
- Density Functional Theory (2)
- Density functional theory (2)
- Hamiltonian systems (2)
- High power lasers (2)
- Interferometry (2)
- Lasers (2)
- Malware (Computer software) (2)
- Mobile computing (2)
- Nanoparticles (2)
- Neural networks (Computer science) (2)
- Optimization (2)
- Rubidium (2)
- Sensitivity (2)
- Silane (2)
- Spectrum analysis (2)
Articles 31 - 60 of 216
Full-Text Articles in Entire DC Network
Functionalization Of Diamond And Its Application In High Performance Liquid Chromatography And Solid Phase Extraction, Gaurav Saini
Functionalization Of Diamond And Its Application In High Performance Liquid Chromatography And Solid Phase Extraction, Gaurav Saini
Theses and Dissertations
The primary focus of my work was to chemically functionalize diamond as normal and reversed phases for solid phase extraction (SPE) and high performance liquid chromatography (HPLC). Diamond was functionalized with -NH2 groups via self-limiting adsorption of an amine-containing polymer, polyallylamine (PAAm), onto oxidized diamond particles. The chemical stability of these particles was improved by thermal curing or chemical crosslinking with 1,2,5,6-diepoxycyclooctane. The reversed phase material for SPE was synthesized by reacting amine-functionalized diamond particles with long chain alkyl and a perfluorinated isocyanate. Unlike commercially available silica, functionalized diamond particles were stable under extreme pH conditions (pH 0-14). Functionalized diamond …
Pixel Based Note Taking Through Perceptual Structure Inference, Mitchell Kent Harris
Pixel Based Note Taking Through Perceptual Structure Inference, Mitchell Kent Harris
Theses and Dissertations
Knowledge workers need effective annotation tools to assimilate information. Unfortunately many digital annotators are limited in the range of document that they accept. Those that do accept many different documents do so by converting documents to images, thus losing any awareness about the original content of the document. We introduce a digital note taker that is both universal and content aware. By constructing a hierarchical context tree of document images, the structure of a document is inferred from the image. This hierarchical context tree is shown to be useful by demonstrating how it facilitates selection of document elements, reflowing documents …
Electronic Structure Based Classification Of Neurotransmitters And Related Drugs, Amrita Jha
Electronic Structure Based Classification Of Neurotransmitters And Related Drugs, Amrita Jha
Theses and Dissertations
A fundamental understanding of the relationship between structure and activity of neurotransmitters in the human brain is of vital importance for the design targeted drugs. Using density functional theory and hybrid exchange correlation energy functionals we have studied the structure-activity-relationships of some important neurotransmitters and selected drugs by calculating their absolute hardness (η) and absolute electronegativity (χ). A plot of the η- χ diagram allowed us to assign them into three distinct groups, namely, (i) Acetylcholine analogs (positively charged structure), (ii) GABA analogs (zwitterionic structures) and (iii) monoamines. The results suggest that brain stem is chemically soft because of distribution …
Polymeric Monolithic Stationary Phases For Capillary Hydrophobic Interaction Chromatography, Yuanyuan Li
Polymeric Monolithic Stationary Phases For Capillary Hydrophobic Interaction Chromatography, Yuanyuan Li
Theses and Dissertations
Rigid poly[hydroxyethyl acrylate-co-poly(ethylene glycol) diacrylate] (Poly(HEA-co-PEGDA) monoliths were synthesized inside 75-µm i.d. capillaries by one-step UV-initiated copolymerization using methanol and ethyl ether as porogens. The optimized monolithic column was evaluated for hydrophobic interaction chromatography (HIC) of standard proteins. Six proteins were separated within 20 min with high resolution using a 20 min elution gradient, resulting in a peak capacity of 54. The performance of this monolithic column for HIC was comparable or superior to the performance of columns packed with small particles. Monoliths synthesized solely from PEGDA were also found to show excellent performance in HIC …
Relational Database Management Systems (Rdms) Sistemet E Menaxhimit Te Bazës Së Të Dhënave Relacionale, Visar Kastrati
Relational Database Management Systems (Rdms) Sistemet E Menaxhimit Te Bazës Së Të Dhënave Relacionale, Visar Kastrati
Theses and Dissertations
Informacionet janë burime mjaft të vlefshme në një organizatë. Softuerët kompjuterik sigurojnë një mënyrë efikase të procesimit të informatave, ku sistemet e bazave të të dhënave janë duke pësuar një rritje mjaft të madhe dhe janë bërë mjaft të zakonshme me anë të cilave bëhet e mundur të ruhen dhe të korrigjohen informatat në mënyrë efektive. Tema mbulon një krahasim në mes të sistemeve te menaxhimit të bazave të të dhënave (database management system). Kjo siguron që të krijohet një kuptim më i mirë i modelimit relacional të të dhënave (relational data modeling), qëllimin e tyre, natyrën dhe standardet të …
Generalized Acoustic Energy Density And Its Applications, Buye Xu
Generalized Acoustic Energy Density And Its Applications, Buye Xu
Theses and Dissertations
The properties of acoustic kinetic energy density and total energy density of sound fields in lightly damped enclosures have been explored thoroughly in the literature. Their increased spatial uniformity makes them more favorable measurement quantities for various applications than acoustic potential energy density (or squared pressure), which is most often used. In this dissertation, a new acoustic energy quantity, the generalized acoustic energy density (GED), will be introduced. It is defined by introducing weighting factors, α and 1 − α, in the formulation of total acoustic energy density. With the additional degree of freedom, the GED can conform to the …
Application Of Convex Methods To Identification Of Fuzzy Subpopulations, Ryan Lee Eliason
Application Of Convex Methods To Identification Of Fuzzy Subpopulations, Ryan Lee Eliason
Theses and Dissertations
In large observational studies, data are often highly multivariate with many discrete and continuous variables measured on each observational unit. One often derives subpopulations to facilitate analysis. Traditional approaches suggest modeling such subpopulations with a compilation of interaction effects. However, when many interaction effects define each subpopulation, it becomes easier to model membership in a subpopulation rather than numerous interactions. In many cases, subjects are not complete members of a subpopulation but rather partial members of multiple subpopulations. Grade of Membership scores preserve the integrity of this partial membership. By generalizing an analytic chemistry concept related to chromatography-mass spectrometry, we …
Code White: A Signed Code Protection Mechanism For Smartphones, Joseph M. Hinson Iv
Code White: A Signed Code Protection Mechanism For Smartphones, Joseph M. Hinson Iv
Theses and Dissertations
This research develops Code White, a hardware-implemented trusted execution mechanism for the Symbian mobile operating system. Code White combines a signed whitelist approach with the execution prevention technology offered by the ARM architecture. Testing shows that it prevents all untrusted user applications from executing while allowing all trusted applications to load and run. Performance testing in contrast with an unmodified Symbian system shows that the difference in load time increases linearly as the application file size increases. The predicted load time for an application with a one megabyte code section remains well below one second, ensuring uninterrupted experience for the …
Cyber Situational Awareness Using Live Hypervisor-Based Virtual Machine Introspection, Dustyn A. Dodge
Cyber Situational Awareness Using Live Hypervisor-Based Virtual Machine Introspection, Dustyn A. Dodge
Theses and Dissertations
In this research, a compiled memory analysis tool for virtualization (CMAT-V) is developed as a virtual machine introspection (VMI) utility to conduct live analysis during cyber attacks. CMAT-V leverages static memory dump analysis techniques to provide live dynamic system state data. Unlike some VMI applications, CMAT-V bridges the semantic gap using derivation techniques. CMAT-V detects Windows-based operating systems and uses the Microsoft Symbol Server to provide this context to the user. This research demonstrates the usefulness of CMAT-V as a situational awareness tool during cyber attacks, tests the detection of CMAT-V from the guest system level and measures its impact …
Accelerating Malware Detection Via A Graphics Processing Unit, Nicholas S. Kovach
Accelerating Malware Detection Via A Graphics Processing Unit, Nicholas S. Kovach
Theses and Dissertations
Real-time malware analysis requires processing large amounts of data storage to look for suspicious files. This is a time consuming process that (requires a large amount of processing power) often affecting other applications running on a personal computer. This research investigates the viability of using Graphic Processing Units (GPUs), present in many personal computers, to distribute the workload normally processed by the standard Central Processing Unit (CPU). Three experiments are conducted using an industry standard GPU, the NVIDIA GeForce 9500 GT card. The goal of the first experiment is to find the optimal number of threads per block for calculating …
Reputation-Based Internet Protocol Security: A Multilayer Security Framework For Mobil Ad Hoc Networks, Timothy H. Lacey
Reputation-Based Internet Protocol Security: A Multilayer Security Framework For Mobil Ad Hoc Networks, Timothy H. Lacey
Theses and Dissertations
This research effort examines the theory, application, and results for a Reputation-based Internet Protocol Security (RIPSec) framework that provides security for an ad-hoc network operating in a hostile environment. In RIPSec, protection from external threats is provided in the form of encrypted communication links and encryption-wrapped nodes while internal threats are mitigated by behavior grading that assigns reputations to nodes based on their demonstrated participation in the routing process. Network availability is provided by behavior grading and round-robin multipath routing. If a node behaves faithfully, it earns a positive reputation over time. If a node misbehaves (for any number of …
Determining The Index Of Refraction Of An Unknown Object Using Passive Polarimetric Imagery Degraded By Atmospheric Turbulence, Milo W. Hyde Iv
Determining The Index Of Refraction Of An Unknown Object Using Passive Polarimetric Imagery Degraded By Atmospheric Turbulence, Milo W. Hyde Iv
Theses and Dissertations
In this research, an algorithm is developed to estimate the index of refraction of an unknown object using passive polarimetric images degraded by atmospheric turbulence. The algorithm uses a variant of the maximum-likelihood blind-deconvolution algorithm developed by LeMaster and Cain to recover the true object (i.e., the first Stokes parameter), the degree of linear polarization, and the polarimetric-image point spread functions. Nonlinear least squares is then used to find the value of the complex index of refraction which best fits the theoretical degree of linear polarization, derived using a polarimetric bidirectional reflectance distribution function, to the turbulence-corrected degree of linear …
Statistical Image Recovery From Laser Speckle Patterns With Polarization Diversity, Donald B. Dixon
Statistical Image Recovery From Laser Speckle Patterns With Polarization Diversity, Donald B. Dixon
Theses and Dissertations
This research extends the theory and understanding of the laser speckle imaging technique. This non-traditional imaging technique may be employed to improve space situational awareness and image deep space objects from a ground-based sensor system. The use of this technique is motivated by the ability to overcome aperture size limitations and the distortion effects from Earth’s atmosphere. Laser speckle imaging is a lensless, coherent method for forming two-dimensional images from their autocorrelation functions. Phase retrieval from autocorrelation data is an ill-posed problem where multiple solutions exist. This research introduces polarization diversity as a method for obtaining additional information so the …
Hijacking User Uploads To Online Persistent Data Repositories For Covert Data Exfiltration, Curtis P. Barnard
Hijacking User Uploads To Online Persistent Data Repositories For Covert Data Exfiltration, Curtis P. Barnard
Theses and Dissertations
As malware has evolved over the years, it has gone from harmless programs that copy themselves into other executables to modern day botnets that perform bank fraud and identity theft. Modern malware often has a need to communicate back to the author, or other machines that are also infected. Several techniques for transmitting this data covertly have been developed over the years which vary significantly in their level of sophistication. This research creates a new covert channel technique for stealing information from a network by piggybacking on user-generated network traffic. Specifically, steganography drop boxes and passive covert channels are merged …
A Comparative Analysis Of Ascii And Xml Logging Systems, Eric C. Hanington
A Comparative Analysis Of Ascii And Xml Logging Systems, Eric C. Hanington
Theses and Dissertations
This research compares XML and ASCII based event logging systems in terms of their storage and processing efficiency. XML has been an emerging technology, even for security. Therefore, it is researched as a logging system with the mitigation of its verbosity. Each system consists of source content, the network transmission, database storage, and querying which are all studied as individual parts. The ASCII logging system consists of the text file as source, FTP as transport, and a relational database system for storage and querying. The XML system has the XML files and XML files in binary form using Efficient XML …
Neural Extensions To Robust Parameter Design, Bernard Jacob Loeffelholz
Neural Extensions To Robust Parameter Design, Bernard Jacob Loeffelholz
Theses and Dissertations
Robust parameter design (RPD) is implemented in systems in which a user wants to minimize the variance of a system response caused by uncontrollable factors while obtaining a consistent and reliable system response over time. We propose the use of artificial neural networks to compensate for highly non-linear problems that quadratic regression fails to accurately model. RPD is conducted under the assumption that the relationship between system response and controllable and uncontrollable variables does not change over time. We propose a methodology to find a new set of settings that will be robust to moderate system degradation while remaining robust …
Consistency Properties For Growth Model Parameters Under An Infill Asymptotics Domain, David T. Mills
Consistency Properties For Growth Model Parameters Under An Infill Asymptotics Domain, David T. Mills
Theses and Dissertations
Growth curves are used to model various processes, and are often seen in biological and agricultural studies. Underlying assumptions of many studies are that the process may be sampled forever, and that samples are statistically independent. We instead consider the case where sampling occurs in a finite domain, so that increased sampling forces samples closer together, and also assume a distance-based covariance function. We first prove that, under certain conditions, the mean parameter of a fixed-mean model cannot be estimated within a finite domain. We then numerically consider more complex growth curves, examining sample sizes, sample spacing, and quality of …
Laser Demonstration And Performance Characterization Of An Optically Pumped Alkali Laser System, Clifford V. Sulham
Laser Demonstration And Performance Characterization Of An Optically Pumped Alkali Laser System, Clifford V. Sulham
Theses and Dissertations
Diode Pumped Alkali Lasers (DPALs) offer a promising approach for high power lasers in military applications that will not suffer from the long logistical trails of chemical lasers or the thermal management issues of diode pumped solid state lasers. This research focuses on characterizing a DPAL-type system to gain a better understanding of using this type of laser as a directed energy weapon. A rubidium laser operating at 795 nm is optically pumped by a pulsed titanium sapphire laser to investigate the dynamics of DPALs at pump intensities between 1.3 and 45 kW/cm2. Linear scaling as high as …
Collisional Dynamics Of The Cesium D1 And D2 Transitions, Greg A. Pitz
Collisional Dynamics Of The Cesium D1 And D2 Transitions, Greg A. Pitz
Theses and Dissertations
The collisional dynamics of the 62P levels in cesium have been studied utilizing steady state laser absorption and laser induced florescence techniques. In addition the production of a blue beam produced by two photon absorption has been observed in potassium. The collisional broadening rate for cesium, λL, for He, Ne, Ar, Kr, Xe, N2, H2, HD, D2, CH4, C2H6, CF4, and 3He are 24.13, 10.85, 18.31, 17.82, 19.74, 16.64, 20.81, 20.06, 18.04, 29.00, 26.70, 18.84, and 26.00 MHz/torr, respectively for the …
Axial Temperature Gradients In Gas Chromatography, Jesse Alberto Contreras
Axial Temperature Gradients In Gas Chromatography, Jesse Alberto Contreras
Theses and Dissertations
The easiest and most effective way to influence the separation process in gas chromatography (GC) is achieved by controlling the temperature of the chromatographic column. In conventional GC, the temperature along the length of the column is constant at any given time, T(t). In my research, I investigated the effects of temperature gradients on GC separations as a function of time and position, T(t,x), along the column. This separation mode is called thermal gradient GC (TGGC). The research reported in this dissertation highlights the fundamental principles of axial temperature gradients and the separation potential of the TGGC technique. These goals …
Windows Xp Embedded Operating System Design, Bashkim Çerkini
Windows Xp Embedded Operating System Design, Bashkim Çerkini
Theses and Dissertations
Windows XP embedded (XPe) është para se gjithash një komplet i veglave që mundëson ndërtimin e një versioni me porosi të Windows XP Professional. Duke zgjedhur vetëm komponentët qe ju nevojitën mund të zhvillohet një sistem operativ (SO) me të gjitha karakteristikat që i kërkon projekti përkatës. Kjo domethënë se programet e zakonshme të Windows-it duke përfshire edhe programet .NET based mund të ekzekutohen në sistemin operativ tuaj përderisa ju i keni përfshirë të gjitha komponentët që programi juaj mbështetët. Për shembull nuk mund të ekzekutoni asnjë aplikacion të rrjetit pa i perfshirë komponentet e rrjetit.Windows XP Embedded është një …
Php & Mysql Simple Project Management Application, Vedat Shaqiri
Php & Mysql Simple Project Management Application, Vedat Shaqiri
Theses and Dissertations
Starting building an application is not that easy at all, especially when people are not experienced enough with the tools needed to cook it. This thesis contains a brief introduction to an PHP & MySQL application. Just as said some lines before, when you get into a thing that you might not be familiar with, difficulties appear, at this time patience and dedication come in to play realizing and making it become true. PHP and MySQL offer a great opportunity building dynamic web sites and application. It is not PHP that makes a web site or an application to become …
All Solid-State Mid-Ir Laser Development, Nonlinear Absorption Investigation And Laser-Induced Damage Study, Torrey J. Wagner
All Solid-State Mid-Ir Laser Development, Nonlinear Absorption Investigation And Laser-Induced Damage Study, Torrey J. Wagner
Theses and Dissertations
In this research, nonlinear optical absorption coefficients and laser-induced damage thresholds are measured in Ge and GaSb, which are materials that are used in IR detectors. Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, two-photon and free-carrier absorption coefficients are measured in Ge and GaSb at 2.05 and 2.5 μm for the first time. At these wavelengths, nonlinear absorption is the primary damage mechanism, and damage thresholds at picosecond and nanosecond pulse widths were measured and agreed well with modeled thresholds using experimentally measured parameters. The damage threshold for a single-layer Al …
Unusual-Object Detection In Color Video For Wilderness Search And Rescue, Daniel Richard Thornton
Unusual-Object Detection In Color Video For Wilderness Search And Rescue, Daniel Richard Thornton
Theses and Dissertations
Aircraft-mounted cameras have potential to greatly increase the effectiveness of wilderness search and rescue efforts by collecting photographs or video of the search area. The more data that is collected, the more difficult it becomes to process it by visual inspection alone. This work presents a method for automatically detecting unusual objects in aerial video to assist people in locating signs of missing persons in wilderness areas. The detector presented here makes use of anomaly detection methods originally designed for hyperspectral imagery. Multiple anomaly detection methods are considered, implemented, and evaluated. These anomalies are then aggregated into spatiotemporal objects by …
Integrated Affinity Column Capillary Electrophoresis Microdevices For Biomarker Analysis, Weichun Yang
Integrated Affinity Column Capillary Electrophoresis Microdevices For Biomarker Analysis, Weichun Yang
Theses and Dissertations
In this dissertation, microfluidic systems that integrate antibody-based sample preparation methods with electrophoretic separation are developed to analyze multiple biomarkers in a point-of-care setting. To form an affinity column, both monolith materials and wall-coated channels were explored. I successfully demonstrated that monolith columns can be prepared in microfluidic devices via photopolymerization. The selectivity of monolith columns was improved by immobilizing antibodies on the surface. These affinity columns can selectively enrich target analytes and reduce the signal of contaminant proteins up to 25,000 fold after immunoaffinity extraction. These results clearly demonstrate that microchip affinity monoliths can selectively concentrate and purify target …
Acoustical Analysis Of A Horn-Loaded Compression Drivers Using Numerical Analysis, Daniel Ross Tengelsen
Acoustical Analysis Of A Horn-Loaded Compression Drivers Using Numerical Analysis, Daniel Ross Tengelsen
Theses and Dissertations
Two numerical techniques, the boundary-element method (BEM) and the finite-difference method (FDM), are used for simulating the radiation from horn-loaded compression drivers and from an infinitely-baffled, finite-length pipe. While computations of the horn-loaded compression driver are in steady state, transient analysis of the finite-length pipe is studied as a precursor to transient analysis within the horn-loaded compression driver. BEM numerical simulations show promise for the development of new designs. Numerical simulations serve as a good tool for time and cost-effective prototyping as poor designs are detected before they are built.
Synthesis And Characterization Of An Oligothiophene-Ruthenium Complex And Synthesis And Optical Properties Of Oligothiophene-Ruthenium Complexes Bound To Cdse Nanoparticles, Nathan A. Bair
Theses and Dissertations
Oligothiophenes are of increasing interest in organic based electronic devices in part due to their high electron and hole mobilities. In an organic photovoltaic (OPV) device, the electronic properties of oligothiophenes make them advantageous as charge transfer junctions. To serve as charge transfer junctions, oligothiophenes must be functionalized to bind to the donor and acceptor parts of the device. The donor and acceptor parts are different materials and the synthesis of asymmetric oligothiophenes is of great interest. Previous researchers in our lab synthesized four asymmetric oligothiophenes, two with two thiophene subunits and two with four. Each set of oligothiophenes contained …
Backflip: A Principled Approach To Online Attribute Verification, Devlin R. Daley
Backflip: A Principled Approach To Online Attribute Verification, Devlin R. Daley
Theses and Dissertations
As traditional interactions in the real-word move online, services that require verified personal information from web users will increase. We propose an architecture for the verification of web user attributes without the use of cryptographic-based credentials. In this architecture, service providers are delegated a user's ability to directly contact a certifying party and retrieve attribute data. We demonstrate that this approach is simple for both developers and users, can be applied to existing Internet facilities and sufficiently secure for typical web use cases.
Temperature And Variability Of Three Ionian Volcanoes, Daniel R. Allen
Temperature And Variability Of Three Ionian Volcanoes, Daniel R. Allen
Theses and Dissertations
Cassini spacecraft images of Io obtained during its flyby of Jupiter in late 2000 and early 2001 were used to determine the lava composition and eruption style of three faint hotspots, Pillan, Wayland, and Loki. We found a maximum color temperature of 1130+/-289 K for Pillan and maximum color temperatures of 1297+/-289 K and 1387+/-287 K for Wayland and Loki, respectively. These temperatures are suggestive of basaltic lava. The temperatures with the best signal-to-noise ratios also suggested basaltic lava and were found to be 780+/-189 K, 1116+/-250 K, and 1017+/-177 K for Pillan, Wayland, and Loki, respectively. Pillan showed increased …
Interactive Object Selection And Matting For Video And Images, Brian L. Price
Interactive Object Selection And Matting For Video And Images, Brian L. Price
Theses and Dissertations
Video segmentation, the process of selecting an object out of a video sequence, is a fundamentally important process for video editing and special effects. However, it remains an unsolved problem due to many difficulties such as large or rapid motions, motion blur, lighting and shadow changes, complex textures, similar colors in the foreground and background, and many others. While the human vision system relies on multiple visual cues and higher-order understanding of the objects involved in order to perceive the segmentation, current algorithms usually depend on a small amount of information to assist a user in selecting a desired object. …