Physical Sciences and Mathematics Commons^™

Velocity Distribution Of Dark Matter Halos: A Critical Test For The Λ Cold Dark Matter Model, Robert Jo Thompson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The existence of a bullet cluster (such as 1E0657-56) poses a challenge to the concordance cold dark matter model. Here we investigate the velocity distribution of dark matter halo pairs in large N-body simulations with differing box sizes and resolutions. We examine various basic statistics such as halo masses, relative halo velocities, collisional angles, and separation distances in our simulations. We then compare the results to the observational properties of 1E0657-56. Our results suggest that it is very difficult to produce such a halo pair with such a high relative velocity at a redshift of z=0. The relative velocities increase …

Using Matrix Pencils To Solve Discrete Sturm-Liouville Problems With Nonlinear Boundary Conditions, Michael Kofi Wilson

Theses, Dissertations and Culminating Projects

This thesis deals with discrete second order Sturm-Liouville Boundary Value Problems (DSLBVP) where the parameter as part of the Sturm-Liouville difference equation appears nonlinearly in the boundary conditions. We focus on analyzing the case with cubic nonlinearity in the boundary condition. First, we describe the problem by a matrix equation with nonlinear variables such that solving the DSLBVP is equivalent to solving the matrix equation. Second, we formulate the problem as a nonlinear eigenvalue problem. We further reduce the problem to finding eigenvalues of a matrix pencil in the form A - X B . Under certain conditions, such a …

Exploiting Query Logs For Cross-Lingual Query Suggestions., Wei Gao, Cheng Niu, Jian-Yun Nie, Ming Zhou, Kam-Fai Wong, Hsiao-Wuen Hon

Research Collection School Of Computing and Information Systems

Query suggestion aims to suggest relevant queries for a given query, which helps users better specify their information needs. Previous work on query suggestion has been limited to the same language. In this article, we extend it to cross-lingual query suggestion (CLQS): for a query in one language, we suggest similar or relevant queries in other languages. This is very important to the scenarios of cross-language information retrieval (CLIR) and other related cross-lingual applications. Instead of relying on existing query translation technologies for CLQS, we present an effective means to map the input query of one language to queries of …

Web2se: First Workshop On Web 2.0 For Software Engineering, Christoph Treude, Margaret-Anne Storey, Kate Ehrlich, Arie Van Deursen

Research Collection School Of Computing and Information Systems

Social software is built around an "architecture of participation" where user data is aggregated as a side-effect of using Web 2.0 applications. Web 2.0 implies that processes and tools are socially open, and that content can be used in several different contexts. Web 2.0 tools and technologies support interactive information sharing, data interoperability and user centered design. For instance, wikis, blogs, tags and feeds help us organize, manage and categorize content in an informal and collaborative way. One goal of this workshop is to investigate how these technologies can improve software development practices. Some of these technologies have made their …

A Comparative Exploration Of Freebsd Bug Lifetimes, Gargi Bougie, Christoph Treude, Daniel M. Germán, Margaret-Anne Storey

Research Collection School Of Computing and Information Systems

In this paper, we explore the viability of mining the basic data provided in bug repositories to predict bug lifetimes. We follow the method of Lucas D. Panjer as described in his paper, Predicting Eclipse Bug Lifetimes. However, in place of Eclipse data, the FreeBSD bug repository is used. We compare the predictive accuracy of five different classification algorithms applied to the two data sets. In addition, we propose future work on whether there is a more informative way of classifying bugs than is considered by current bug tracking systems.

Aquatic Habitat Mapping Within The Obed Wild And Scenic River For Threatened And Endangered Species Habitat Delineation, Joseph Ross Candlish

Masters Theses

There is a need to define a more efficient and accurate approach to aquatic habitat mapping. Traditional approaches have focused on intense biological/non-biological sampling and observation analysis within specific and restrained scales. Therefore, an underwater video mapping system (UVMS) has been developed in efforts to identify federally protected aquatic species’ habitats within the Obed Wild and Scenic River (OBRI). The UVMS kayak apparatus provides georeferenced video footage correlated with GPS (global positioning systems) for GIS (geographic information systems) mapping applications. Based on its fluvial and geomorphological trends, OBRI was dissected quantitatively and integrated into databases for species-specific GIS habitat queries. …

Identification Of Phosphatases Involved In E2f-Associated Apoptosis, Liza D. Morales Smith

Theses and Dissertations - UTB/UTPA

Retinoblastoma (Rb) is a tumor suppressor protein that controls a critical checkpoint between the G1 phase and the S phase of the cell cycle. Rb is able to suppress cell proliferation by binding to the E2F family of transcription factors, inhibiting its ability to activate transcription of genes necessary for cell cycle progression. Mutations in proteins involved with the Rb/E2F pathway can result in hyper-proliferative cells that overtime can acquire and accumulate additional mutations, which could lead to tumorigenesis. To prevent hyper-proliferation, aberrant cells can be eliminated through apoptosis. E2F can induce apoptosis through two pathways: through transactivation of the …

Neutrosophic Physics: More Problems, More Solutions, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

When considering the laws of theoretical physics, one of the physicists says that these laws – the actual expressions of the laws of mathematics and logics being applied to physical phenomena – should be limited according to the physical meaning we attribute to the phenomena. In other word, there is an opinion that a theoretical physicist should put some limitations onto mathematics, in order to “reduce” it to the observed reality. No doubt, we can do it. However, if following this way, we would arrive at only mathematical models of already known physical phenomena. Of course, this might be useful …

Towards Finding Robust Execution Strategies For Rcpsp/Max With Durational Uncertainty, Na Fu, Pradeep Varakantham, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Resource Constrained Project Scheduling Problems with minimum and maximum time lags (RCPSP/max) have been studied extensively in the literature. However, the more realistic RCPSP/max problems — ones where durations of activities are not known with certainty – have received scant interest and hence are the main focus of the paper. Towards addressing the significant computational complexity involved in tackling RCPSP/max with durational uncertainty, we employ a local search mechanism to generate robust schedules. In this regard, we make two key contributions: (a) Introducing and studying the key properties of a new decision rule to specify start times of activities with …

A Statewide Seidment And Water Quality Approach To Characterize Pollution In Wadable Streams Of South Carolina, Alan Jones

All Theses

At present, little data is available concerning the overall quality of small aquatic ecosystems in South Carolina. The data presented here comprises the elemental contamination results from the first two years of an ongoing study with the South Carolina Department of Natural Resources of wadeable streams in South Carolina. The overall goal of this thesis is to assess overall ecosystem quality in order to provide information needed for improved management strategies. The data focus on elemental contaminants found in water and sediments in 2006 and 2007 and relationships between metals and land cover in the drainage areas or watersheds of …

Handling Concept Drift In Text Data Stream Constrained By High Labelling Cost, Patrick Lindstrom, Sarah Jane Delany, Brian Mac Namee

Conference papers

In many real-world classification problems the concept being modelled is not static but rather changes over time - a situation known as concept drift. Most techniques for handling concept drift rely on the true classifications of test instances being available shortly after classification so that classifiers can be retrained to handle the drift. However, in applications where labelling instances with their true class has a high cost this is not reasonable. In this paper we present an approach for keeping a classifier up-to-date in a concept drift domain which is constrained by a high cost of labelling. We use …

Voluntary Green Power Market Forecast Through 2015, Lori Bird, Ed Holt, Jenny Sumner, Claire Kreycik

Publications (E)

Voluntary markets for renewable energy in which consumers purchase renewable energy from their electricity providers or from renewable energy certificate (REC) marketers have existed for more than a decade. Going forward, various factors will influence the development of these markets, including potential climate policies, state and federal renewable portfolio standards (RPS), renewable energy prices, the level of consumer interest in purchasing green power, and the interest on the part of utilities in offering new green options and in continuing to promote existing programs.

This report presents estimates of voluntary market demand for renewable energy or green power through 2015. The …

Co And H+3 Toward Mwc 1080, Mwc 349, And Lkhα 101, E L. Gibb, Sean D. Brittain, T W. Rettig, M Troutman, Theodore Simon, C Kulesa

Publications

We present high-resolution, near-infrared NIRSPEC observations of the fundamental rovibrational CO and H+ 3 R(1,0), R(1,1) u , and Q(1,0) transitions toward three early-type young stars: MWC 1080, MWC 349, and LkHα 101. These observations were performed for the purpose of constraining the physical characteristics of the interstellar material along each line of sight. Toward MWC 1080, we detected strong CO absorption and determined a column density upper limit of 1.4 × 1014 cm–2 for H+ 3. We infer that there is very little diffuse material along the line of sight toward MWC 1080 and that the CO absorption is …

All-Sky Search For Gravitational-Wave Bursts In The First Joint Ligo-Geo-Virgo Run, J. Abadie, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present results from an all-sky search for unmodeled gravitational-wave bursts in the data collected by the LIGO, GEO 600 and Virgo detectors between November 2006 and October 2007. The search is performed by three different analysis algorithms over the frequency band 50-6000 Hz. Data are analyzed for times with at least two of the four LIGO-Virgo detectors in coincident operation, with a total live time of 266 days. No events produced by the search algorithms survive the selection cuts. We set a frequentist upper limit on the rate of gravitational-wave bursts impinging on our network of detectors. When combined …

Avian Piscivores As Vectors For Myxobolus Cerebralis In The Greater Yellowstone Ecosystem, Todd M. Koel, Billie L. Kerans, Scott C. Barras, Katie C. Hanson, John S. Wood

United States Department of Agriculture Wildlife Services: Staff Publications

Myxobolus cerebralis, the cause of whirling disease in salmonids, has dispersed to waters in 25 states within the USA, often by an unknown vector. Its incidence in Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri within the highly protected environment of Yellowstone Lake, Yellowstone National Park, is a prime example. Given the local abundances of piscivorous birds, we sought to clarify their potential role in the dissemination of M. cerebralis. Six individuals from each of three bird species (American white pelican Pelecanus erythrorhynchos, double-crested cormorant Phalacrocorax auritus, and great blue heron Ardea herodias) were fed known-infected or …

Facilitating Behavior Change Of Coastal Communities In Regards To Climatic Hazards, Marisa Nixon

Senior Honors Projects

For my Senior Honors Project I participated in the Climate Change Collaborative, which is a new interdisciplinary research project studying the ways in which coastal communities in Rhode Island can better adapt to the environmental, cultural and economic consequences of climate change. As a member of this collaborative, I worked in a vertically integrated team of faculty (psychology researchers, climate scientists and communications science practitioners and researchers) as well as undergraduate and graduate students, to begin an endeavor through which behavior change will be assessed in regards to climate change. For the purposes of this study, we specifically focus on …

Optimal Control In Discrete Pest Control Models, Kathryn Dabbs

Chancellor’s Honors Program Projects

No abstract provided.

Influence Of Clay Mineralogy On Soil Dispersion Behavior And Water Quality, Jessique L. Ghezzi

Master's Theses

Currently, there is very little research available on nonpoint source pollution from rural watersheds. Government regulatory agencies are desperate for information regarding the causes of nonpoint source pollution, which includes the relationship between suspended soil particles and dispersion. Since soil dispersion is dependent on clay mineralogy, knowing the clay mineralogy of the soil in an area can help predict sediment loads entering the surrounding surface waters. This information is necessary to protect the resource value of our rivers, lakes, and estuaries, as well as to protect recreational activities such as fishing or hunting; but most importantly, this information is necessary …

Global Warming Advocacy Science: A Cross Examination, Jason S. Johnston

All Faculty Scholarship

Legal scholarship has come to accept as true the various pronouncements of the Intergovernmental Panel on Climate Change (IPCC) and other scientists who have been active in the movement for greenhouse gas (ghg) emission reductions to combat global warming. The only criticism that legal scholars have had of the story told by this group of activist scientists – what may be called the climate establishment – is that it is too conservative in not paying enough attention to possible catastrophic harm from potentially very high temperature increases. This paper departs from such faith in the climate establishment by comparing the …

Molecular Design And Patterning Of Biosurfaces On Poly(Tetrafluoroethylene) (Ptfe), Nattharika Aumsuwan

Dissertations

This dissertation describes the design, synthesis, and development of biocompatible poly(tetrafluoroethylene) (PTFE) surfaces that exhibit anti-microbial, anticoagulant, and dual functional surface properties. It consists of two parts: (1) design, synthesis, and analysis of antimicrobial and anti-coagulant PTFE surfaces, and (2) controllable micropatterning of anti-microbial and anti-coagulant species on the surface. PTFE was modified by Ar microwave plasma reactions in the presence of maleic anhydride, which upon hydrolysis creating COOH groups. These COOH primers were utilized as a platform for further surface reactions to attach polyethylene glycol (PEG) spacers, and penicillin (PEN) or ampicillin (AM) onto the PTFE surfaces. The use …

Nanomaterials From Biologically Active Molecules: Self-Assembly And Molecular Recognition, Min Yu

Dissertations

This dissertation describes the development of molecular assemblies and molecular recognition of phospholipids (PLs) that exhibit potential applications in emerging nanotechnologies. It consists of two parts: (1) structural features of PLs responsible for recognition of synthetic copolymers, and (2) design, synthesis and analysis of magnetic nanotubes obtained from PLs with a common theme of colloidal synthesis served as a platform for film formation and nano-assemblies of nanotubes. Poly(methyl methacrylate/n-butyl acrylate) (p-MMA/nBA) colloidal particles that were stabilized by 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) PLs were synthesized, and upon the particle coalescence, PL stratification resulted in the formation of surface localized ionic clusters (SLICs). These …

Aqueous Raft Synthesis Of Stimuli-Responsive, Amphiphilic Block Copolymers And Self-Assembly Behavior In Solution And Incorporation Into Lbl Films, Matthew Grady Kellum

Dissertations

Of all the living radical polymerization techniques, reversible addition– fragmentation chain transfer (RAFT) polymerization is arguably the most versatile in terms of the reaction conditions (e.g. temperature and solvent selection), monomer selection (e.g. neutral, anionic, cationic, and zwitterionic), and purification. Since the introduction of RAFT in 1998, the McCormick research group and others including the Lowe, Sumerlin, and Davis research groups have synthesized a wide range of (co)polymers with predetermined molecular weights, low polydispersities, and advanced architectures utilizing aqueous RAFT (ARAFT) polymerization. These research groups have also studied how various block copolymers exhibit stimuli-responsive behavior due to a change in …

Multi Stimuli-Responsive Copolymers Obtained From Colloidal Dispersions, Fang Liu

Dissertations

This dissertation describes the design, synthesis, and development of multi stimuli-responsive random copolymers that exhibit collective responsiveness to temperature, pH or electromagnetic radiation. New colloidal particles of poly(N-(DL)-(1- Hydroxyymethyl) propylmethacrylamide/n-butyl acrylate) (p(DL-HMPMA/nBA) and poly(2-(N,N′-dimethylamino)ethyl methacrylate/n-butyl acrylate) (p(DMAEMA/nBA)) were synthesized, which upon coalesce to form solid continuous films. The presence of lower glass transition (Tg) nBA components not only facilitate film formation, but also provide sufficient free volume for polymer chain rearrangements. These studies showed that coalesced films exhibit 3D dimensional changes upon external stimuli, which are attributed to the collapse and conformational changes of stimuli-responsive components as well as buckling …

Keeping Wetlands Wet: The Human Hydrology Of Wetlands In The Bear River Basin, Rebekah Downard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research seeks to understand how wetlands maintain a water supply in the Bear River Basin, where water is generally scarce. Research was conducted through semi-structured interviews with wetland and water experts in the basin and archival research of historical documents and water rights.

The U. S. Fish and Wildlife Service manages three refuges on the Bear River, and has obtained water rights portfolios for each. Holding water rights does not ensure that there will be water available for refuge wetlands. Instead, position in relation to other powerful water users is the most important factor in determining the security of …

Generation And Analysis Of Verbal Route Directions For Blind Navigation, John Nicholson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

According to the National Federation of the Blind, there are an estimated 10 million people in the United States who are visually impaired. Of these, 1.3 million are legally blind. Many people with extreme vision loss receive orientation and mobility training in order to help them learn skills that allow them to travel and navigate multiple types of indoor and outdoor environments. Even with this training, a fundamental problem these people face is learning new routes, especially in environments with which they are not familiar. Although the research community has developed a number of localization and navigation aids that are …

On The Cover

Sci-Tech News

Frontismatter of the issue and explanation of the cover illustration, courtesy of the Linda Hall Library of Science, Engineering & Technology.

Call For Articles

Sci-Tech News

No abstract provided.

From The Editor

Sci-Tech News

No abstract provided.

The History Of The Senator Claiborne Deb. Pell Marine Science Library, Alexander Burnett

Sci-Tech News

An account of the founding and development of one of the leading marine science libraries of the world.

Science Today In Verse, Hope Leman

Sci-Tech News

A more light-hearted look at science.