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2008

Utah State University

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Articles 31 - 60 of 106

Full-Text Articles in Physical Sciences and Mathematics

Strides Towards Better Application Security, Sathyaraj Balasubramanian Dec 2008

Strides Towards Better Application Security, Sathyaraj Balasubramanian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Static analysis tools analyze source code for vulnerabilities. However, these types of tools suffer from various problems that limit their effectiveness. This thesis examines these static analysis tools and suggests techniques for making them more efficient at detecting different types of vulnerabilities.

The thesis further analyzes possible causes for these vulnerabilities by examining the source code written by programmers of various categories. Finally, this thesis discusses solutions and techniques to improve general security awareness as well as the importance of secure coding among the students and software developers.


Pulse-Laser Infrared Photothermal Spectrometry Of Condensed-Phase Aerosols Based On Photothermal Deflection Spectroscopy, Oluwatosin Olubunmi Dada Dec 2008

Pulse-Laser Infrared Photothermal Spectrometry Of Condensed-Phase Aerosols Based On Photothermal Deflection Spectroscopy, Oluwatosin Olubunmi Dada

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research reported in this dissertation is aimed at development of photothermal deflection detector that is consistent with constraints imposed by aerosols sampling and analysis. The main objectives of this project are: 1) the design and evaluation of initial apparatus prototypes and 2) a test of the prototype apparatus with surrogate substances using conventional mid-infrared gas lasers.

Experimental evaluation of reduced size photothermal apparatus is first performed with gaseous samples. Analysis of trichlorofluoromethane (CFC-11) and ethanol vapors is performed with both conventional large apparatus and the prototype small apparatus. Comparison studies in terms of photothermal signal from both apparatuses are …


Extending F10.7'S Time Resolution To Capture Solar Flare Phenomena, Ariel O. Acebal Dec 2008

Extending F10.7'S Time Resolution To Capture Solar Flare Phenomena, Ariel O. Acebal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solar ultraviolet (UV) radiation ionizes the neutral components in the atmosphere, which is partly responsible for the formation of the ionosphere, and contributes to heating of the atmosphere. Solar flares change the solar spectrum at times by several orders of magnitude. These changes modify the Earth's upper atmosphere, causing problems to communication systems and space operations, such as increased satellite drag. Unfortunately, solar UV measurements are limited since they can only be observed with space-based sensors. In order to work around this limitation, the solar radio emissions at a wavelength of 10.7 cm have been used as a proxy for …


What Are Consumers In Moyale, Kenya Willing To Pay For Improved Milk Quality?, D. Layne Coppock, Francis O. Wayua, Mohamed G. Shibia, Moses S. Mamo Dec 2008

What Are Consumers In Moyale, Kenya Willing To Pay For Improved Milk Quality?, D. Layne Coppock, Francis O. Wayua, Mohamed G. Shibia, Moses S. Mamo

Environment and Society Faculty Publications

Pastoralists in northern Kenya and southern Ethiopia may be able to diversify income by selling milk to urban residents. However, milk sold in open-air markets is often low in quality because it has been transported long distances without refrigeration and is subject to spoilage, or because milk is adulterated prior to sale to boost volume or enhance appearance. Open-air markets are characterized by low-income consumers who must make choices about milk quality with virtually no information other than their own sensory perceptions. PARIMA researchers used an experimental-auction approach to determine what residents in Moyale, Kenya, are willing to pay (WTP) …


Successful Implementation Of Collective Action And Human-Capacity Building Among Pastoralists In Southern Ethiopia: Lessons Learned, 2001-2008, D. Layne Coppock, Seyoum Tezera, Solomon Desta, Getachew Gebru Dec 2008

Successful Implementation Of Collective Action And Human-Capacity Building Among Pastoralists In Southern Ethiopia: Lessons Learned, 2001-2008, D. Layne Coppock, Seyoum Tezera, Solomon Desta, Getachew Gebru

Environment and Society Faculty Publications

Since 2000 the PARIMA project has implemented pilot risk-management activities among poverty-stricken, semi-settled pastoralists in southern Ethiopia. The goal has been to improve human welfare via collective action and capacity building. Outcomes include progress in income generation, asset conservation, and livelihood diversification. The approach has been unique to southern Ethiopia in that a bottom-up, participatory perspective has dominated. It has focused on the priorities and felt needs of local people rather than top-down development of livestock or agricultural technology. Fifty-nine collective-action groups were created. Dominated by women, they have included over 2,300 members and most groups have been recently merged …


Are Cattle Die-Offs Predictable On The Borana Plateau, D. Layne Coppock, Getachew Gebru, Solomon Desta, Sintayehu Mesele, Seyoum Tezerra Dec 2008

Are Cattle Die-Offs Predictable On The Borana Plateau, D. Layne Coppock, Getachew Gebru, Solomon Desta, Sintayehu Mesele, Seyoum Tezerra

Environment and Society Faculty Publications

Drought regularly affects rangelands and contributes to high death rates for livestock and poverty for pastoralists. But do livestock losses occur randomly simply when rainfall is low, or are they cyclical and predictable? Previously, PARIMA researchers proposed that high stocking rates—combined with low rainfall—trigger livestock die-offs on the Borana Plateau. It takes about six years for animal numbers to recover, setting the stage for another die-off when a dry year occurs. This “boom-and-bust” cycle is based on observed herd crashes in 1983-5, 1991-3, and 1998-9. Researchers predicted in 2002 that the next major die-off would occur during 2004-06, and one …


A C To Register Transfer Level Algorithm Using Structured Circuit Templates: A Case Study With Simulated Annealing, Jonathan D. Phillips Dec 2008

A C To Register Transfer Level Algorithm Using Structured Circuit Templates: A Case Study With Simulated Annealing, Jonathan D. Phillips

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A tool flow is presented for deriving simulated annealing accelerator circuits on a field programmable gate array (FPGA) from C source code by exploring architecture solutions that conform to a preset template through scheduling and mapping algorithms. A case study carried out on simulated annealing-based Autonomous Mission Planning and Scheduling (AMPS) software used for autonomous spacecraft systems is explained. The goal of the research is an automated method for the derivation of a hardware design that maximizes performance while minimizing the FPGA footprint. Results obtained are compared with a peer C to register transfer level (RTL) logic tool, a state-of-the-art …


A Three-Dimensional, Time-Dependent Circulation Model Of Utah Lake, Eric V. Callister Dec 2008

A Three-Dimensional, Time-Dependent Circulation Model Of Utah Lake, Eric V. Callister

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spatial and temporal variations of Utah Lake’s flow field were modeled using the Estuary Lake and Computer Model from the Centre for Water Research (CWR-ELCOM) at the University of Western Australia as part of an effort to increase understanding of the lake’s natural processes in order to restore the lake to its pristine, clear-water state and preserve the habitat of the June sucker, an endangered species. The model was validated using temperature measurements taken by sensors in 2007. The water temperature was a strong function of air temperature and incident short wave radiation, and was influenced to a lesser degree …


A Novel Technique Of Network Auditability With Managers In The Loop, Rian Shelley Dec 2008

A Novel Technique Of Network Auditability With Managers In The Loop, Rian Shelley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Network management requires a large amount of knowledge about the network. In particular, knowledge about used network addresses, access time, and topology is useful. In a network composed of managed devices, much of the data necessary can come from simple network management protocol (SNMP) queries. Other data can come from other databases, or analysis of existing data. In particular, layer-two network topology can be determined by analyzing the mac address forwarding tables of layer-two devices. The layer-two topology can be merged with a layer-three topology to generate a complete topology of the network. This information is useless unless it is …


A Novel Authentication And Validation Mechanism For Analyzing Syslogs Forensically, Steena D.S. Monteiro Dec 2008

A Novel Authentication And Validation Mechanism For Analyzing Syslogs Forensically, Steena D.S. Monteiro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research proposes a novel technique for authenticating and validating syslogs for forensic analysis. This technique uses a modification of the Needham Schroeder protocol, which uses nonces (numbers used only once) and public keys. Syslogs, which were developed from an event-logging perspective and not from an evidence-sustaining one, are system treasure maps that chart out and pinpoint attacks and attack attempts. Over the past few years, research on securing syslogs has yielded enhanced syslog protocols that focus on tamper prevention and detection. However, many of these protocols, though efficient from a security perspective, are inadequate when forensics comes into play. …


Nutrient Loading And Eutrophication In The Great Salt Lake, Wayne A. Wurtsbaugh Nov 2008

Nutrient Loading And Eutrophication In The Great Salt Lake, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

No abstract provided.


Gravity Has A Story To Tell: Lisa And The Search For Low Frequency Gravitational Waves, Shane L. Larson Nov 2008

Gravity Has A Story To Tell: Lisa And The Search For Low Frequency Gravitational Waves, Shane L. Larson

Colloquia and Seminars

No abstract provided.


Usu’S Rayleigh-Scatter Lidar, Vincent B. Wickwar Oct 2008

Usu’S Rayleigh-Scatter Lidar, Vincent B. Wickwar

Presentations

No abstract provided.


One With The Cosmos: A Short Tour Out Your Backdoor, Shane L. Larson Oct 2008

One With The Cosmos: A Short Tour Out Your Backdoor, Shane L. Larson

Public Talks

No abstract provided.


Seasonal Variations Of Semidiurnal Tidalperturbations In Mesopause Region Temperature And Zonal And Meridional Winds Above Fort Collins, Colorado(40.6°N, 105.1°W), Tao Yuan, H. Schmidt, C. Y. She, D. A. Krueger, S. Reising Oct 2008

Seasonal Variations Of Semidiurnal Tidalperturbations In Mesopause Region Temperature And Zonal And Meridional Winds Above Fort Collins, Colorado(40.6°N, 105.1°W), Tao Yuan, H. Schmidt, C. Y. She, D. A. Krueger, S. Reising

All Physics Faculty Publications

On the basis of Colorado State University (CSU) Na lidar observations over full diurnal cycles from May 2002 to April 2006, a harmonic analysis was performed to extract semidiurnal perturbations in mesopause region temperature and zonal and meridional winds over Fort Collins, Colorado (40.6°N, 105.1°W). The observed monthly results are in good agreement with MF radar tidal climatology for Urbana, Illinois, and with predictions of the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), sampled at the CSU Na lidar coordinates. The observed semidiurnal tidal period perturbation within the mesopause region is found to be dominated by propagating modes …


Seasonal And Longitudinal Dependence Of Equatorialdisturbance Vertical Plasma Drifts, Bela G. Fejer, J. W. Jensen, S. Y. Su Oct 2008

Seasonal And Longitudinal Dependence Of Equatorialdisturbance Vertical Plasma Drifts, Bela G. Fejer, J. W. Jensen, S. Y. Su

Bela G. Fejer

[1] We used equatorial measurements from the ROCSAT-1 satellite to determine the seasonal and longitudinal dependent equatorial F region disturbance vertical plasma drifts. Following sudden increases in geomagnetic activity, the prompt penetration vertical drifts are upward during the day and downward at night, and have strong local time dependence at all seasons. The largest prompt penetration drifts near dusk and dawn occur during June solstice. The daytime disturbance dynamo drifts are small at all seasons. They are downward near dusk with largest (smallest) values during equinox (June solstice); the nighttime drifts are upward with the largest magnitudes in the postmidnight …


Deep Dielectric Charging Of Spacecraft Polymers By Energetic Protons, Nelson W. Green, Jr Dennison Oct 2008

Deep Dielectric Charging Of Spacecraft Polymers By Energetic Protons, Nelson W. Green, Jr Dennison

Journal Articles

The majority of research in the field of spacecraft charging concentrates on electron charging effects with little discussion of charging by protons. For spacecraft orbiting in the traditional LEO and GEO environments, this emphasis on electrons is appropriate since energetic electrons are the dominant species. However, for spacecraft in orbits within the inner radiation belts, or for interplanetary and lunar space probes, proton charging effects may also be of concern. To examine bulk spacecraft charging effects in these environments, several typical highly insulating spacecraft polymers were exposed to energetic protons with energies from 1 to 10 MeV to simulate protons …


Low-Fluence Electron Yields Of Highly Insulating Materials, Ryan Hoffmann, Jr Dennison, Clint D. Thomson, Jennifer Albretson Oct 2008

Low-Fluence Electron Yields Of Highly Insulating Materials, Ryan Hoffmann, Jr Dennison, Clint D. Thomson, Jennifer Albretson

Journal Articles

Electron-induced electron yields of high-resistivity, high-yield materials - ceramic polycrystalline aluminum oxide and the polymer polyimide (Kapton HN), - were made by using a low-fluence, pulsed incident electron beam and charge neutralization electron source to minimize charge accumulation. Large changes in energy-dependent total yield curves and yield decay curves were observed, even for incident electron fluences of <3 fC/mm2. The evolution of the electron yield as charge accumulates in the material is modeled in terms of electron re-capture based on an extended Chung-Everhart model of the electron emission spectrum. This model is used to explain anomalies measured in highly insulating, …


Microtextural Constraints On The Interplay Between Fluidrockreactions And Deformation, Alexis K. Ault, Jane Selverstone Oct 2008

Microtextural Constraints On The Interplay Between Fluidrockreactions And Deformation, Alexis K. Ault, Jane Selverstone

Geosciences Faculty Publications

Schists from two mylonitic localities in the footwall of a low-angle normal fault in the eastern Alps record different degrees of embrittlement during exhumation, depending on the extent to which fluid–rock reactions proceeded. At one site, graphitic schists preserve textural evidence for two metamorphic reactions that modified XCO2XCO2 and/or fluid volume: (1) reaction between graphite and aqueous fluid that increased XCO2XCO2 without changing the molar amount of fluid, and (2) replacement of titanite by rutile, calcite, and quartz. The latter reaction involved net consumption of increasingly CO2-rich fluid. Areas where the first reaction proceeded are associated with abundant Mode I …


Low-Fluence Electron Yields Of Highly Insulating Materials, Ryan Hoffman, John R. Dennison, Clint D. Thomson, Jennifer Albresten Oct 2008

Low-Fluence Electron Yields Of Highly Insulating Materials, Ryan Hoffman, John R. Dennison, Clint D. Thomson, Jennifer Albresten

All Physics Faculty Publications

Electron-induced electron yields of high-resistivity high-yield materials - ceramic polycrystalline aluminum oxide and polymer polyimide (Kapton HN) - were made by using a low-fluence pulsed incident electron beam and charge neutralization electron source to minimize charge accumulation. Large changes in the energy-dependent total yield curves and yield decay curves were observed, even for incident electron fluences of < 3 fC/mm2. The evolution of the electron yield as charge accumulates in the material is modeled in terms of electron recapture based on an extended Chung-Everhart model of the electron emission spectrum. This model is used to explain the anomalies measured in highly …


Temperature And Electric Field Dependence Of Conduction In Low-Density Polyethylene, John R. Dennison, Jerilyn Brunson Oct 2008

Temperature And Electric Field Dependence Of Conduction In Low-Density Polyethylene, John R. Dennison, Jerilyn Brunson

All Physics Faculty Publications

A traditional constant voltage conductivity test method was used to measure how the conductivity of highly insulating low-density polyethylene (LDPE) polymer films depends on applied electric field, repeated and prolonged electric field exposure, and sample temperature. The strength of the applied voltage was varied to determine the electric field dependence. At low electric field, the resistivity was measured from cryogenic temperatures to well above the glass transition temperature. Comparisons were made with a variety of models of the conduction mechanisms common in insulators, including transient polarization and diffusion and steady-state thermally activated hopping conductivity and variable range hopping conductivity, to …


Gravity Wave And Tidal Influences On Equatorial Spread F Based On Observations During The Spread F Experiment (Spreadfex), D. C. Fritts, S. L. Vadas, D. M. Riggin, M. A. Abdu, I. S. Batista, H. Takahashi, A. Medeiros, F. Kamalabadi, H. L. Liu, B. G. Fejer, Michael J. Taylor Oct 2008

Gravity Wave And Tidal Influences On Equatorial Spread F Based On Observations During The Spread F Experiment (Spreadfex), D. C. Fritts, S. L. Vadas, D. M. Riggin, M. A. Abdu, I. S. Batista, H. Takahashi, A. Medeiros, F. Kamalabadi, H. L. Liu, B. G. Fejer, Michael J. Taylor

All Physics Faculty Publications

The Spread F Experiment, or SpreadFEx, was performed from September to November 2005 to define the potential role of neutral atmosphere dynamics, primarily gravity waves propagating upward from the lower atmosphere, in seeding equatorial spread F (ESF) and plasma bubbles extending to higher altitudes. A description of the SpreadFEx campaign motivations, goals, instrumentation, and structure, and an overview of the results presented in this special issue, are provided by Fritts et al. (2008a). The various analyses of neutral atmosphere and ionosphere dynamics and structure described in this special issue provide enticing evidence of gravity waves arising from deep convection in …


Movement Strategies Of Seed Predators As Determinants Of Plant Recruitment Patterns, Lorenzo Mari, Renato Casagrandi, Marino Gatto, Tal Avgar, Ran Nathan Sep 2008

Movement Strategies Of Seed Predators As Determinants Of Plant Recruitment Patterns, Lorenzo Mari, Renato Casagrandi, Marino Gatto, Tal Avgar, Ran Nathan

Wildland Resources Faculty Publications

Plant recruitment in nature exhibits several distinctive patterns ranging from hump shaped to monotonically decreasing with distance from the seed source. We investigate the role of post-dispersal seed predation in shaping these patterns, introducing a new mechanistic model that explicitly accounts for the movement strategy used by seed eaters. The model consists of two partial differential equations describing the spatiotemporal dynamics of both seed and predator densities. The movement strategy is defined by how predators move in response to the different cues they can use to search for seeds. These cues may be seed density, seed intake, distance from the …


On A New Process For Cusp Irregularity Production, Herbert C. Carlson, K. Oksavik, J. Moen Sep 2008

On A New Process For Cusp Irregularity Production, Herbert C. Carlson, K. Oksavik, J. Moen

Faculty publications

Two plasma instability mechanisms were thought until 2007 to dominate the formation of plasma irregularities in the F region high latitude and polar ionosphere; the gradient-drift driven instability, and the velocity-shear driven instability. The former mechanism was accepted as accounting for plasma structuring in polar cap patches, the latter for plasma structuring in polar cap sun aligned arcs. Recent work has established the need to replace this view of the past two decades with a new patch plasma structuring process (not a new mechanism), whereby shear-driven instabilities first rapidly structure the entering plasma, after which gradient drift instabilities build on …


Vignettes From The World Of Gravitational Wave Astrophysics, Shane L. Larson Sep 2008

Vignettes From The World Of Gravitational Wave Astrophysics, Shane L. Larson

Colloquia and Seminars

No abstract provided.


Songs From The Milky Way: Our Galaxy In Low Frequency Gravitational Waves, Shane L. Larson Sep 2008

Songs From The Milky Way: Our Galaxy In Low Frequency Gravitational Waves, Shane L. Larson

Colloquia and Seminars

No abstract provided.


How Movement Properties Affect Prey Encounter Rates Of Ambush Versus Active Predators: A Comment On Scharf Et Al, Tal Avgar, Nir Horvitz, Luba Broitman, Ran Nathan Sep 2008

How Movement Properties Affect Prey Encounter Rates Of Ambush Versus Active Predators: A Comment On Scharf Et Al, Tal Avgar, Nir Horvitz, Luba Broitman, Ran Nathan

Wildland Resources Faculty Publications

Using an individual‐based model, Scharf and coworkers showed that ambush predators may encounter prey more frequently than active predators. We show that this surprising result emerges because active predators were oblivious to prey during movement, an assumption that refutes the common conception about active foraging and lessens the key difference between these foraging modes. A revised model confirms that active predators always encounter prey more frequently, unequivocally supporting the authors’ conclusion that the advantage of active predators diminishes as prey moves faster or more directionally. We suggest that movement‐dependent perception quality can determine the relative efficiency of these two foraging …


Low-Fluence Electron Yields Of Highly Insulating Materials, Ryan Hoffmann, John R. Dennison Aug 2008

Low-Fluence Electron Yields Of Highly Insulating Materials, Ryan Hoffmann, John R. Dennison

All Physics Faculty Publications

Electron-induced electron yields of high-resistivity, high-yield materials - ceramic polycrystalline aluminum oxide and the polymer polyimide (Kapton HN), - were made by using a low-fluence, pulsed incident electron beam and charge neutralization electron source to minimize charge accumulation. Large changes in energy-dependent total yield curves and yield decay curves were observed, even for incident electron fluences of


Starlight In The Night: Discovering The Secret Lives Of Stars, Shane L. Larson Aug 2008

Starlight In The Night: Discovering The Secret Lives Of Stars, Shane L. Larson

Public Talks

No abstract provided.


Richfield Field Office Planning Area - Proposed Resource Management And Final Environmental Impact Statement, United States Department Of The Interior, Bureau Of Land Management Aug 2008

Richfield Field Office Planning Area - Proposed Resource Management And Final Environmental Impact Statement, United States Department Of The Interior, Bureau Of Land Management

Final environmental Impact Statements (UT)

The Proposed RMP was crafted primarily from the Preferred Alternative presented in the DRMP/DEIS (Alternative B) and includes other decisions within the range of alternatives (Alternatives N, A, C, and D) in response to public comments and internal review. The No Action Alternative (Alternative N) reflects current management. The BLM has removed the DRMP/DEIS Alternative B (Preferred Alternative) from the PRMP/FEIS. The other DRMP/DEIS Alternatives (Alternatives N, A, C, and D) and analyses are carried forward in the PRMP/FEIS only for comparative purposes and to correct some mistakes that were identified during the public comment period.