Physical Sciences and Mathematics Commons^™

Hunting For Undetectable Metamorphic Viruses, Da Lin

Master's Projects

Commercial anti-virus scanners are generally signature based, that is, they scan for known patterns to determine whether a file is infected by a virus or not. To evade signature-based detection, virus writers have adopted code obfuscation techniques to create highly metamorphic computer viruses. Since metamorphic viruses change their appearance from generation to generation, signature-based scanners cannot detect all instances of such viruses. To combat metamorphic viruses, detection tools based on statistical analysis have been studied. A tool based on hidden Markov models (HMMs) was previously developed and the results are encouraging—it has been shown that metamorphic viruses created by a …

Improving Location Determination For Non-Gps Devices, Varun Sud

Master's Projects

Location awareness is one of the most important information that an individual looks for, both in an outdoor and indoor environment. One of the primary location determination techniques is the Global Positioning system, though this system provides a good accuracy in an outdoor environment, its accuracy decreases in densely populated areas and in an indoor environment a GPS system ceases to provide location information since the satellite signal cannot permeate through the roof and the walls. Various location estimation techniques have been proposed for location estimation in an indoor environment, some utilizing the signal strength of a wifi transmitter, while …

Priority Based Power Management And Reduced Downtime In Data Centers, Barath Kuppuswamy

Master's Projects

The project deals successfully with software that performs priority based power management and reduced downtime for virtual machines running in data centers. The software deals with power management only at the processor level. The software automatically performs load distribution among servers in data centers to save power. In addition, the software also lets administrator of data centers to mark certain virtual machines, which run user applications, as critical to minimize downtimes for these virtual machines. The software reveals that energy consumption can be minimized while maintaining high runtime availability for the mission critical applications. The software operates in Green mode …

Seeing Shifts: Ecologists' Lived Experiences Of Climate Change In Mountains Of The American West, Kimberly Ford Langmaid

Antioch University Dissertations & Theses

This study explores the lived experiences of field ecologists who research the effects of global climate change on mountain species and ecosystems in the American West. The purpose is to generate narrative descriptions of ecologists’ experiences in order to communicate about both the scientific ecology and human ecology of climate change. Twenty prominent field ecologists participated in this study. Interviews with ecologists were transcribed and analyzed using a hermeneutic phenomenological methodology. Eight experiential themes emerged through the process of data analysis, and these themes provide the structure for presenting narratives of ecologists’ experiences. The eight themes are: thinking ecologically, the …

Ecosystems Services Of Tidal Shorelines, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

Rivers & Coast is a periodic publication of the Center for Coastal Resources Management, Virginia Institute of Marine Science. The goal of Rivers & Coast is to keep readers well informed of current scientific understanding behind key environmental issues related to watershed rivers and coastal ecosystems of the Chesapeake Bay.

Summary Tables: Mathews County, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky, Daniel E. Schatt, David Weiss

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

Vims Response To Climate Change 2009, United Nations Environmental Programme : Responding To Climate Change In The Coastal Zone, Virginia Institute Of Marine Science. Initiative For Coastal Climate Change Research

Reports

VIMS Response to Climate Change 2009 United Nations Environmental Program Responding to climate change in the coastal zone

Observing And Modeling Global Warming Impacts In Virginia, Mark R. Patterson, Mark Brush, Marjorie A.M. Friedrichs, Virginia Institute Of Marine Science. Initiative For Coastal Climate Change Research

Reports

VIMS climate change white paper: Observing and modeling global warming impacts in Virginia

Extreme Storm Events Increase The Risk For Chemical Contamination Of Coastal Waters, Michael A. Unger, Virginia Institute Of Marine Science. Initiative For Coastal Climate Change Research

Reports

Sea-level rise and an increase in the severity of coastal storms are probable outcomes for the Chesapeake Bay due to global climate change. A consequent ecological and economic risk for tidewater Virginia and other low-lying coastal zones is the contamination of coastal waters by industrial and agricultural chemicals released by accidental spills during severe storm events. . . .

Progress In Strategic Research Areas, Scott R. Abella

Public Policy and Leadership Faculty Publications

Three years ago through conversations with resource managers, assessing the status of knowledge of the scientific literature, and our own interests, we set forth several strategic research areas that we believed would be timely for advancing Mojave Desert conservation and management.

Early Post-Fire Plant Establishment On A Mojave Desert Burn, Scott R. Abella, E. Cayenne Engel, Christina L. Lund, Jessica E. Spencer

Public Policy and Leadership Faculty Publications

Fire has become more extensive in recent decades in southwestern United States arid lands. Burned areas pose management challenges and opportunities, and increasing our understanding of post-fire plant colonization may assist management decision-making. We examined plant communities, soils, and soil seed banks two years after the 2005 Loop Fire, located in a creosote-blackbrush community in Red Rock Canyon National Conservation Area in southern Nevada’s Mojave Desert. Based on a spring sampling of 20, 0.01-ha plots, live + dead cover of the exotic annual Bromus rubens averaged nine times lower on the burn than on a paired unburned area. Perennial species …

Eastern Nebraska Water Resources Assessment (Enwra): Introduction To A Hydrogeological Study, Dana Divine, R. Matthew Joeckel, Jesse T. Korus, P.R. Hanson, Sue Olafsen Lackey

Conservation and Survey Division

No abstract provided.

Soil Carbon And Nitrogen Accumulation In A Forested Debris Flow Chronosequence, California, Judith K. Turk, Robert C. Graham

Conservation and Survey Division

The role of forest soils in the biogeochemical cycling of C and N is most dynamic during the early stages of soil development. To define C and N trends that occur with soil development in a mixed coniferous forest, a chronosequence formed by debris flows was studied. The accumulation rates of total organic C (TOC) and total N (TN) were evaluated in soils on 10 debris flow deposits, ranging from depth, since this was the depth of the shallowest debris flows. Carbon was found to accumulate in the organic horizons at a rate of 26.5 g m⁻² yr^{−1 …}

Pilot Study: The Nature And Thickness Of The Unsaturated Zone And Delineation Of Confined Aquifers, Sue Olafsen Lackey, Les Howard

Conservation and Survey Division

No abstract provided.

Nebraska Statewide Groundwater-Level Monitoring Report 2009, Jesse T. Korus Dr., Mark E. Burbach

Conservation and Survey Division

No abstract provided.

Systematic Analysis Of Identifying Key Dimensions Of Environmentally And Socially Responsible Hotels, Courtney Suess

UNLV Theses, Dissertations, Professional Papers, and Capstones

Development in Southeast Asia involves making good decisions for the future, so the idea that good planning can ignore sustainability is something of an oxymoron. Good development has to be sustainable and we have reached a point where the old ways of tourism development are intolerable. For example, hotels spring up without planning for the future. This short sightedness means natural endowments, like coastlines, erode and forests are cut down, chasing away the wildlife; or cultural history in the form of temples, historic buildings, and sacred places are destroyed. Ironically, tourism development is eradicating the very forms of product that …

Reduction Of Calcium Release Site Models Via Fast/Slow Analysis And Iterative Aggregation/Disaggregation, Yan Hao, Peter Kemper, Gregory D. Smith

Arts & Sciences Articles

Mathematical models of calcium release sites derived from Markov chain models of intracellular calcium channels exhibit collective gating reminiscent of the experimentally observed phenomenon of calcium puffs and sparks. Such models often take the form of stochastic automata networks in which the transition probabilities of each channel depend on the local calcium concentration and thus the state of the other channels. In order to overcome the state-space explosion that occurs in such compositionally defined calcium release site models, we have implemented several automated procedures for model reduction using fast/slow analysis. After categorizing rate constants in the single channel model as …

Water Use And Natural Limits In The Las Vegas Valley: A History Of The Southern Nevada Water Authority, Christian Harrison

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis examines the history of the Southern Nevada Water Authority (SNWA) and how it has helped transform various aspects of southern Nevada's economy and environment. Prior to the establishment of the SNWA in 1991 the Las Vegas Metropolitan Area (LVMA) possessed several competing water providers whose opposition to one another adversely affected the management of water in the region. These water providers recognized this problem, came together, and negotiated the creation of a regional water agency, the SNWA. This organization, comprised of representatives from each of the LVMA's water providers has the power to institute policy across municipal boundaries. …

Sequence And Chemostratigraphic Study Across The Basal Eureka Quartzite Unconformity In The Great Basin, Nevada: Implications For The Origin Of The Late Ordovician Carbon Isotope Excursion, Apostolos Paul Kosmidis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The positive carbon isotope (δ 13 C) excursion from the late Middle Ordovician Copenhagen Formation that underlies the Eureka Quartzite in central Nevada has been hypothesized to record a global cooling event ∼10 Myr prior to the well-recognized Late Ordovician Hirnantian glaciation (∼443 Ma). However, direct evidence for pre-Hirnantian continental glaciation remains scarce, raising uncertainties in the relationship between the inferred eustatic sea-level fall and the origin of the positive δ 13 C excursion. Additionally, previous stratigraphic studies from southern Nevada and California suggest relative sea-level fall in excess of ∼ 150 meters, which exceeds estimates for younger glacial periods …

Mineralogy And Micromorphology Of An Atacama Desert Soil, Chile: A Model For Hyperarid Pedogenesis, Michael S. Howell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Atacama Desert is the oldest and driest desert on Earth. Hyperarid soils in this desert are dominated by rare (or exclusive) salt minerals and assemblages. Previous research details salt origins and abundance, however pedogenic processes involved in salt distribution are not adequately explained. Therefore, the main goal of this investigation was to identify and document evidence for hyperarid pedogenesis (via salt mineralogy and soil micromorphology) at a field site, Oficina Ercilla, located ~80 km northeast of Antofagasta, Chile within the Central Depression and hyperarid core of the Atacama Desert. This study presents an interpretational model for hyperarid pedogenesis, which …

Effects Of Similarity Metrics On Document Clustering, Rushikesh Veni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Document clustering or unsupervised document classification is an automated process of grouping documents with similar content. A typical technique uses a similarity function to compare documents. In the literature, many similarity functions such as dot product or cosine measures are proposed for the comparison operator.

For the thesis, we evaluate the effects a similarity function may have on clustering. We start by representing a document and a query, both as a vector of high-dimensional space corresponding to the keywords followed by using an appropriate distance measure in k-means to compute similarity between the document vector and the query vector to …

Bending Of Woody Riparian Vegetation As A Function Of Hydraulic Flow Conditions, John O. Goreham

UNLV Theses, Dissertations, Professional Papers, and Capstones

Vegetation encroachment reduces channel conveyance capacity below design objectives and greatly increases the risk for loss of life and property damage in the case of large flood events. Given minimal knowledge of hydraulic roughness for shrubs and woody vegetation, accurate estimation of channel capacity and water surface elevation is difficult. The ability to predict a tree's bent, reduced height in the presence of flow permits more accurate prediction of hydraulic roughness and water surface elevation.

In this study, field tests were performed to elucidate tree bending properties, which in turn served as input parameters for a numerical algorithm designed to …

Effects Of Plant Uptake And Micro-Topography On Chloride Transport In Arid Soils, Wenming Nie

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chloride concentration profiles to depths of 1 m were evaluated on a young alluvial fan in Eldorado Valley, NV. It was found that chloride beneath plant canopies were 11 to 222 times higher than adjacent (1 - 2 m away) bare soil locations. Two-dimensional numerical simulations using HYDRUS 2D/3D model were used to further explore the impact of plants on chloride transport. The simulation results indicated that lateral flow driven by root uptake concentrated chloride toward root zones, leading to the accumulation of chloride under plant canopies. Results also suggest that locally micro-topography can have a substantial impact on chloride …

Geoelectrical Response Of Surfactant Solutions In A Quartzitic Sand Analog Aquifer, Meghan Therese Magill

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this project, the resistivity and phase shift of ten surfactant aqueous solutions in a sand matrix were measured using spectral induced polarization (SIP). In addition, specific conductivity, pH, dissolved oxygen, and dielectric constant measurements of the solutions were also evaluated. The frequency range assessed was 0.091-12000Hz. The surfactants, which are typically used in the remediation of tetrachloroethylene, were Aerosol MA 80-I, Dowfax 8390, and Steol CS-330. The surfactants were mixed into solutions of both deionized and tap water at varying concentrations and injected into a closed system of silica sand. The surfactant treatments altered resistivity, specific conductivity, and pH …

Soil Moisture And Water Stage Estimation Using Precipitation Radar, Sumit Puri

UNLV Theses, Dissertations, Professional Papers, and Capstones

In south-western United States, soil moisture data is important for drought studies in the region which is experiencing a drought for many years, whereas in South Florida, water stage data is required by hydrologists to monitor the hydrological flow in wetlands. Soil moisture data and water stage data are not sufficiently available due to sparse monitoring stations. Installation of dense measuring stations over an extended area is costly and labor intensive. Therefore, there is a need to develop an alternative method of measuring soil moisture and water stage. Microwave remote sensing has proven to be a useful tool in the …

An Evaluation Of Lead Hazards In Pre-1978 Residental Housing Within Clark County, Nevada, Usa, Erika Raquel Torres

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lead poisoning remains a public health concern due to leads persistence in the environment from anthropogenic uses. Initial efforts to address the impacts of lead on vulnerable communities have included secondary prevention measures which typically occur after a child has been poisoned. However, in recent years there has been a pragmatic shift toward primary prevention efforts.

This study evaluates lead hazards identified through primary prevention activities in residential housing within Clark County, Nevada, USA. It is the first study to systematically address and evaluate pre-1978 housing in Southern Nevada. Risk assessments were conducted in 81 dwellings built prior to 1979 …

A Comparison Of Benthic Macroinvertebrate Assemblages Among Kryal And Rhithral Lake Outlets In The North Cascade Mountains, Kelley L. Turner

WWU Graduate School Collection

This study compares the physico-chemical conditions and composition of benthic macroinvertebrates from five rhithral (snowmelt-fed) and five kryal (glacially-fed) lake outlet streams in the North Cascade Mountains, WA. Non-metric, non-parametric cluster and association analysis (NMCAA) clearly separated outlet streams of kryal and rhithral origin based on physico-chemical and taxon variables. Kryal lake outlets were characterized by lower water temperatures, unstable in-stream channels and higher turbidity, discharge and fine substrates than rhithral sites. A total of 24,985 specimens representing 93 macroinvertebrate taxa were collected. Rhithral lake outlets had significantly higher densities and supported more taxa than kryal sites (9,049 ind./m2 and …

Effects Of Salmon-Derived Nutrients On An Artificial Stream System, Danielle M. Love

WWU Graduate School Collection

An artificial stream system was constructed to study responses of autotrophic and heterotrophic stream communities to salmon-derived nutrients. The artificial stream system contained 12 raceways (1.2 m long x 20 cm wide x 13 cm tall) that were provided with a constant flow of well water. The experimental treatment group consisted of clay pots filled with pureed salmon carcasses and agar to simulate decomposing salmon carcasses; a control group was included consisting of pots containing agar without salmon tissue. Unglazed clay tiles were placed downstream from the clay pots for periphyton to colonize. Periphyton samples were collected from these tiles. …

The Generation Of A Diverse Suite Of Late Pleistocene And Holocene Basaltic-Andesite Through Dacite Lavas From The Northern Cascade Arc At Mount Baker, Washington, Troy D. Baggerman

WWU Graduate School Collection

This study highlights geochemical diversity in a spectrum of basaltic andesite through dacite lavas from Mount Baker, WA, and describes processes that are responsible for their generation. Petrographic observations, mineral chemistry, along with whole rock major oxide concentrations, and trace and REE data are provided for three Late Pleistocene and Holocene lava flows: the basaltic andesite of Sulphur Creek (SC) (52.5-55.8 wt.% Si02, Mg# 57-54), the andesite of Glacier Creek (GC) (58.3-58.7 wt.% Si02, Mg # 63-64), and the andesite and dacite of Boulder Glacier (BG) (60.2-64.2 wt.% Si02, Mg # 50-57). Major oxide concentrations for SC and BG display …

A Two-Population Insurgency In Colombia: Quasi-Predator-Prey Models - A Trend Towards Simplicity, John A. Adam, John A. Sokolowski, Catherine M. Banks

Mathematics & Statistics Faculty Publications

A sequence of analytic mathematical models has been developed in the context of the "low-level insurgency" in Colombia, from 1993 to the present. They are based on generalizations of the two-population "predator-prey" model commonly applied in ecological modeling, and interestingly, the less sophisticated models yield more insight into the problem than the more complicated ones, but the formalism is available to adapt the model "upwards" in the event that more data becomes available, or as the situation increases in complexity. Specifically, so-called "forcing terms" were included initially in the coupled differential equations to represent the effects of government policies towards …