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2009

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Articles 151 - 180 of 6337

Full-Text Articles in Physical Sciences and Mathematics

Self-Organized Criticality In Sheared Suspensions, L. Corté, Sharon J. Gerbode, W. Man, D. J. Pine Dec 2009

Self-Organized Criticality In Sheared Suspensions, L. Corté, Sharon J. Gerbode, W. Man, D. J. Pine

All HMC Faculty Publications and Research

Recent studies reveal that suspensions of neutrally buoyant non-Brownian particles driven by slow periodic shear can undergo a dynamical phase transition between a fluctuating irreversible steady state and an absorbing reversible state. Using a computer model, we show that such systems exhibit self-organized criticality when a finite particle sedimentation velocity vs is introduced. Under periodic shear, these systems evolve, without external intervention, towards the shear-dependent critical concentration ϕc as vs is reduced. This state is characterized by power-law distributions in the lifetime and size of fluctuating clusters. Experiments exhibit similar behavior and, as vs is reduced, …


Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner Dec 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …


Using Conservative And Biological Tracers To Better Understand The Transport Of Agricultural Contaminants From Soil Water Through The Epikarstic Zone, Brian Ham Dec 2009

Using Conservative And Biological Tracers To Better Understand The Transport Of Agricultural Contaminants From Soil Water Through The Epikarstic Zone, Brian Ham

Masters Theses & Specialist Projects

Agriculture contamination is very common in karst systems due to the vulnerability of these aquifers. Animal waste is often spread across crop land to enrich the soil with nitrates and phosphates. Herbicides and pesticides are also applied to the crops. The transport of these pollutants through the soil and epikarst is a difficult process to monitor due to the complex, heterogeneous behavior of the groundwater as it makes its way down to the aquifer below.

An experimental site at Crumps Cave lended a unique opportunity to monitor the vadose zone at a waterfall in the cave below. A previous dye …


Random Walks With Elastic And Reflective Lower Boundaries, Lucas Clay Devore Dec 2009

Random Walks With Elastic And Reflective Lower Boundaries, Lucas Clay Devore

Masters Theses & Specialist Projects

No abstract provided.


Kinetic Studies Of The Sulfoxidation Of Aryl Methyl Sulfides By Trans-Dioxoruthenium(Vi) Porphyrin Complexes, Chris Abebrese Dec 2009

Kinetic Studies Of The Sulfoxidation Of Aryl Methyl Sulfides By Trans-Dioxoruthenium(Vi) Porphyrin Complexes, Chris Abebrese

Masters Theses & Specialist Projects

The development of an efficient, catalytically active, biomimetic model for cytochrome P-450 enzymes has been an area of intense research activity. Ruthenium porphyrin complexes have been the center of this research and have successfully been utilized, as catalysts, in major oxidation reactions such as the hydroxylation of alkanes, the epoxidation of alkenes and aromatic rings, and the N-oxidation of amines, among others. In this project, the kinetics of two-electron sulfoxidation of para-substituted phenyl methyl sulfides to the corresponding sulfoxides with well-characterized trans-dioxoruthenium(VI) porphyrin complexes were studied by rapid stopped-flow spectroscopy. The substituent effect in sulfides and in dioxoruthenium(VI) complexes were …


Mining Data From Multiple Software Development Projects, Huanjing Wang, Taghi M. Khoshgoftaar, Kehan Gao, Naeem Seliya Dec 2009

Mining Data From Multiple Software Development Projects, Huanjing Wang, Taghi M. Khoshgoftaar, Kehan Gao, Naeem Seliya

Computer Science Faculty Publications

A large system often goes through multiple software project development cycles, in part due to changes in operation and development environments. For example, rapid turnover of the development team between releases can influence software quality, making it important to mine software project data over multiple system releases when building defect predictors. Data collection of software attributes are often conducted independent of the quality improvement goals, leading to the availability of a large number of attributes for analysis. Given the problems associated with variations in development process, data collection, and quality goals from one release to another emphasizes the importance of …


Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner Dec 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …


Copas: An R Package For Fitting The Copas Selection Model, J. Carpenter, G. Rücker, G. Schhwarzer Dec 2009

Copas: An R Package For Fitting The Copas Selection Model, J. Carpenter, G. Rücker, G. Schhwarzer

The R Journal

This article describes the R package copas which is an add-on package to the R pack age meta. The R package copas can be used to f it the Copas selection model to adjust for bias in meta-analysis. A clinical example is used to illustrate fitting and interpreting the Copas selection model.


Aspects Of The Social Organization And Trajectory Of The R Project, John Fox Dec 2009

Aspects Of The Social Organization And Trajectory Of The R Project, John Fox

The R Journal

Based partly on interviews with members of the R Core team, this paper considers the development of the R Project in the context of open-source software development and, more generally, voluntary activities. The paper de scribes aspects of the social organization of the R Project, including the organization of the R Core team; describes the trajectory of the R Project; seeks to identify factors crucial to the success of R; and speculates about the prospects for R.


Sos: Searching Help Pages Of R Packages, Spencer Graves, Sundar Dorai-Raj, Romain François Dec 2009

Sos: Searching Help Pages Of R Packages, Spencer Graves, Sundar Dorai-Raj, Romain François

The R Journal

The sos package provides a means to quickly and flexibly search the help pages of contributed packages, finding functions and datasets in seconds or minutes that could not be found in hours or days by any other means we know. Its findFn function accesses Jonathan Baron’s R Site Search database and returns the matches in a data frame of class "findFn", which can be further manipulated by other sos functions to produce, for example, an Excel file that starts with a summary sheet that makes it relatively easy to prioritize alternative packages for further study. As such, it provides a …


Party On!, Carolin Strobl, Torsten Hothorn, Achim Zeileis Dec 2009

Party On!, Carolin Strobl, Torsten Hothorn, Achim Zeileis

The R Journal

Random forests are one of the most popular statistical learning algorithms, and a variety of methods for fitting random forests and related recursive partitioning approaches is available in R. This paper points out two important features of the random forest implementation cforest available in the party package: The resulting forests are unbiased and thus prefer able to the randomForest implementation avail able in randomForest if predictor variables are of different types. Moreover, a conditional per mutation importance measure has recently been added to the party package, which can help evaluate the importance of correlated predictor variables. The rationale of this …


Ua12/13 Wku Campus Wide Holiday Energy Conservation Plan, Wku Sustainability Committee, Christian Ryan-Downing Dec 2009

Ua12/13 Wku Campus Wide Holiday Energy Conservation Plan, Wku Sustainability Committee, Christian Ryan-Downing

Sustainability Publications and Resources

No abstract provided.


From The Bronx Into The Wild! My Adventurous Experience At The Bronx Zoo, Lauren Noll Dec 2009

From The Bronx Into The Wild! My Adventurous Experience At The Bronx Zoo, Lauren Noll

Student Theses 2001-2013

Many people defend zoos, claiming that they provide great opportunities in education, scientific research, and the overall preservation of wildlife worldwide. However, many people will take the opposing side, arguing that it is wrong to deprive animals of their natural habitats and lifestyles. One of the greatest controversies of our time pertains to the moral issues associated with keeping animals in captivity, such as in zoos and aquariums.


Social Behaviors Of Modern And Indigenous Peoples Impacting The Ecology Of The Amazon Rain Forest In Brazil, Josef W. Schaffer Dec 2009

Social Behaviors Of Modern And Indigenous Peoples Impacting The Ecology Of The Amazon Rain Forest In Brazil, Josef W. Schaffer

Earth and Soil Sciences

Human induced disruption of the environment is prevalent in every culture. In Brazil, the effects of massive deforestation have become apparent since the nineteen eighties. However, along with deforestation, and a coinciding loss in an economic resource for the country, is a significant loss of natural habitat and species extinction. The Amazon in Brazil contains a large proportion of the world’s species diversity that is threatened by the socio-economic activities of modern Brazilian culture. Historically and presently, indigenous groups have contributed to insignificant levels of ecological disruption and are themselves threatened by the activities of modern Brazilians. The effects of …


Fisheries Research Report No. 197 - Coastal And Marine Resource Condition Monitoring - Scoping Project, Brett A. Human, Justin I. Mcdonald Dec 2009

Fisheries Research Report No. 197 - Coastal And Marine Resource Condition Monitoring - Scoping Project, Brett A. Human, Justin I. Mcdonald

Fisheries Research Reports

Final NRM Report – Project 073007

Part 1– Knowledge review and gap analysis: Resource condition monitoring in the Pilbara and Kimberley regions of Western Australia

This report details extensive literature searches for both research and monitoring programs that have been undertaken in the marine and coastal environments of the Pilbara and Kimberley region of northern Western Australia. The Pilbara and Kimberley region is remote and difficult to access, resulting in very little monitoring effort of the marine and coastal environments in that region.

We currently know very little of the condition of marine and coastal natural resources in the Pilbara …


Pair Creation Rates For One-Dimensional Fermionic And Bosonic Vacua, T Cheng, M R. Ware, Q Su, Rainer Grobe Dec 2009

Pair Creation Rates For One-Dimensional Fermionic And Bosonic Vacua, T Cheng, M R. Ware, Q Su, Rainer Grobe

Faculty publications – Physics

We compare the creation rates for particle-antiparticle pairs produced by a supercritical force field for fermionic and bosonic model systems. The rates obtained from the Dirac and Klein-Gordon equations can be computed directly from the quantum-mechanical transmission coefficients describing the scattering of an incoming particle with the supercritical potential barrier. We provide a unified framework that shows that the bosonic rates can exceed the fermionic ones, as one could expect from the Pauli-exclusion principle for the fermion system. This imbalance for small but supercritical forces is associated with the occurrence of negative bosonic transmission coefficients of arbitrary size for the …


Perturbation Theory Analysis Of Attosecond Photoionization, Anthony F. Starace, Evgeny A. Pronin, M. V. Frolov, N. L. Manakov Dec 2009

Perturbation Theory Analysis Of Attosecond Photoionization, Anthony F. Starace, Evgeny A. Pronin, M. V. Frolov, N. L. Manakov

Anthony F. Starace Publications

Ionization of an atom by a few-cycle attosecond xuv pulse is analyzed using perturbation theory (PT), keeping terms in the transition amplitude up to second order in the pulse electric field. Within the PT approach, we present an ab initio parametrization of the ionized electron angular distribution (AD) using rotational invariance and symmetry arguments. This parametrization gives analytically the dependence of the AD on the carrier envelope phase (CEP), the polarization of the pulse, and on the ionized electron momentum direction, p^ . For the general case of an elliptically polarized pulse, we show that interference of the first- and …


Directed Coverage In Wireless Sensor Networks: Concept And Quality, Xiaole Bai, Lei Ding, Jin Teng, Sriram Chellappan, Changqing Xu, Dong Xuan Dec 2009

Directed Coverage In Wireless Sensor Networks: Concept And Quality, Xiaole Bai, Lei Ding, Jin Teng, Sriram Chellappan, Changqing Xu, Dong Xuan

Computer Science Faculty Research & Creative Works

In this paper, we introduce a new type of coverage for wireless sensor networks, called Directed Coverage (D-Coverage). Basically, D-Coverage is the coverage provided by a sensor network monitoring an area between two boundaries, through which the intruder attempts to penetrates the area. We also study how to measure the quality of D-Coverage. Our first evaluation approach is a projection-Based simple approach, while our second approach is a more comprehensive Markov chain-based approach. Our evaluation approaches can accurately evaluate the quality and provide good guidelines for sensor network deployment and run-time repair. ©2009 IEEE.


Recursive Decomposition Of Progress Graphs, David A. Cape, Bruce M. Mcmillin, Benjamin W. Passer, Mayur Thakur Dec 2009

Recursive Decomposition Of Progress Graphs, David A. Cape, Bruce M. Mcmillin, Benjamin W. Passer, Mayur Thakur

Computer Science Faculty Research & Creative Works

Search of a state transition system is traditionally how deadlock detection for concurrent programs has been accomplished. This paper examines an approach to deadlock detection that uses geometric semantics involving the topo-logical notion of dihomotopy to partition the state space into components; after that the reduced state space is exhaustively searched. Prior work partitioned the state space inductively. in this paper we show that a recursive technique provides greater reduction of the size of the state transition system and therefore more efficient deadlock detection. If the preprocessing can be done efficiently, then for large problems we expect to see more …


Sparql Query Re-Writing For Spatial Datasets Using Partonomy Based Transformation Rules, Prateek Jain, Cory Andrew Henson, Amit P. Sheth, Peter Z. Yeh, Kunal Verma Dec 2009

Sparql Query Re-Writing For Spatial Datasets Using Partonomy Based Transformation Rules, Prateek Jain, Cory Andrew Henson, Amit P. Sheth, Peter Z. Yeh, Kunal Verma

Kno.e.sis Publications

Often the information present in a spatial knowledge base is represented at a different level of granularity and abstraction than the query constraints. For querying ontology’s containing spatial information, the precise relationships between spatial entities has to be specified in the basic graph pattern of SPARQL query which can result in long and complex queries. We present a novel approach to help users intuitively write SPARQL queries to query spatial data, rather than relying on knowledge of the ontology structure. Our framework re-writes queries, using transformation rules to exploit part-whole relations between geographical entities to address the mismatches between query …


A Local Qualitative Approach To Referral And Functional Trust, Krishnaprasad Thirunarayan, Dharan Althuru, Cory Andrew Henson, Amit P. Sheth Dec 2009

A Local Qualitative Approach To Referral And Functional Trust, Krishnaprasad Thirunarayan, Dharan Althuru, Cory Andrew Henson, Amit P. Sheth

Kno.e.sis Publications

Trust and confidence are becoming key issues in diverse applications such as ecommerce, social networks, semantic sensor web, semantic web information retrieval systems, etc. Both humans and machines use some form of trust to make informed and reliable decisions before acting. In this work, we briefly review existing work on trust networks, pointing out some of its drawbacks. We then propose a local framework to explore two different kinds of trust among agents called referral trust and functional trust, that are modelled using local partial orders, to enable qualitative trust personalization. The proposed approach formalizes reasoning with trust, distinguishing between …


Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner Dec 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …


Privacy Preserving Portable Health Record (P³Hr), Pavan Roy Marupally, Vamsi Paruchuri, Sriram Chellappan Dec 2009

Privacy Preserving Portable Health Record (P³Hr), Pavan Roy Marupally, Vamsi Paruchuri, Sriram Chellappan

Computer Science Faculty Research & Creative Works

Personal health records (PHRs) offer significant potential to stimulate transformational changes in health care delivery and self-care by patients. There is a gap between today's personal health records (PHRs) and what patients say they want and need from this electronic tool for managing their health information. Current barriers to PHR adoption among patients include cost, concerns that information is not protected or private, inconvenience, design shortcomings, and the inability to share information across organizations. We propose a novel architecture to bridge the gap based on Privacy Preserving Portable Health Record(P3HR), a device that incorporates a smart card into …


Off-Metal Synthesis Of Some Aryl Substituted Rhenium N5-Cyclopenta [C] Pyridazyl Complexes, James Leif Neathery Dec 2009

Off-Metal Synthesis Of Some Aryl Substituted Rhenium N5-Cyclopenta [C] Pyridazyl Complexes, James Leif Neathery

Masters Theses & Specialist Projects

Heterocyclic organic and organometallic compounds (e.g. polypyrrole), and their derivatives, have been of great interest for conductive polymers due to their novel properties and environmental stability as compared to non-aromatic analogs (e.g. polyacetylene). Our current interests focus upon the potential role of pyridazines in next generation electronic devices that utilize organics as the semiconducting material. Pyridazines, 6-membered aromatic rings with two adjacent nitrogens, are promising candidates for a variety of materials and commercial applications. These molecular electronic materials posses several advantages over traditional inorganic semiconducting materials including lower cost of production, higher processibility, and the ability to function on flexible …


Chemistry Of Zirconia And Its Bioanalytical Applications, Oge Anazia Dec 2009

Chemistry Of Zirconia And Its Bioanalytical Applications, Oge Anazia

Masters Theses & Specialist Projects

This research studies the chemical nature of zirconia and the complex surface chemistry of zirconia in order to better comprehend its behavior under chromatographic conditions. This research shows how the physical and chemical properties of zirconia depend strongly on the thermal treatment during synthesis. The morphology of the samples was also studied. The absorption capability of Adenosine Triphosphate (ATP) on zirconia was also monitored and spectrally characterized.

The results of this research showed how the properties of zirconia vary with thermal treatment. It was observed that the zirconia prepared at a higher temperature had lower surface area, lower pore size …


Analysis Of Mammoth Cave Pre-Park Communities, Matthew Brunt Dec 2009

Analysis Of Mammoth Cave Pre-Park Communities, Matthew Brunt

Masters Theses & Specialist Projects

Before the creation of Mammoth Cave National Park, this area was home to numerous communities, each with a sense of identity. To prepare for the creation of the National Park, all residents living within these communities were relocated, and many of these communities were lost to the passage of time. Today, public memory of these lost communities is being fostered by the descendents of the pre-park area.

Through the use of a Historical Geographic Information System, 1920 Edmonson County manuscript census data, and statistical analysis, the demographic composition of these lost communities was explored. This project not only brought to …


Heirloom And Hybrid Tomato Yield And Quality In Organic And Conventional Production Systems, Diana J. Edlin Dec 2009

Heirloom And Hybrid Tomato Yield And Quality In Organic And Conventional Production Systems, Diana J. Edlin

Masters Theses & Specialist Projects

Due to the recent changes in the economy of Kentucky tobacco production, some producers are seeking an alternative crop that will provide similar economic gains to tobacco without needing more acreage. Tomatoes are an existing crop in Kentucky that have been declining in acreage over the last five years. There is evidence to suggest that, through niche and local marketing, tomatoes may be able to fill the void left by tobacco. However, there is concern among producers that they will lose yield and/or quality if they switch to one of these niche production systems or cultivars.

A two year study …


"All The Crises Reached A Concerted Crescendo" - The Arab Oil Embargo And Why The United States Was Unprepared For It, Jonathan D. Chilcote Dec 2009

"All The Crises Reached A Concerted Crescendo" - The Arab Oil Embargo And Why The United States Was Unprepared For It, Jonathan D. Chilcote

Masters Theses & Specialist Projects

During the 2008 spike in oil prices, oil companies and government officials were brought under close scrutiny as many Americans began to question why prices were able to rise so quickly. Americans had become accustomed to living in an economy where cheap oil was the norm, and demanded answers when that situation changed. What most of them did not know is that they were repeating history and mimicking the response to the 1973 oil embargo. Just as in 2008, the United States faced a crisis in 1973 with which it was unprepared to effectively cope. This thesis analyzes the reasons …


A Study Of The Mesosphere-Lower Thermosphere: Noctilucent Cloud Observations And Rocket Borne Density Measurements, Shelton Simmons Dec 2009

A Study Of The Mesosphere-Lower Thermosphere: Noctilucent Cloud Observations And Rocket Borne Density Measurements, Shelton Simmons

All Theses

Herein, a study of a noctilucent cloud, NLC, display from 17 July 2007 is analyzed. A photogrammetric analysis was applied to time lapsed photographs taken from two observation sites, RŸgen and KŸhlungsborn, Germany. Both Kelvin-Helmholtz instabilities and internal gravity waves were identified during the NLC display based on the typical characteristics of such waves in the mesopause region. With the two observation sites, the location of details can be identified with an accuracy of ±0.125¡ longitude and ±0.5¡ latitude. A gravity wave with a wavelength of 50km and Kelvin-Helmholtz instability or gravity wave of wavelength 16.5km were observed. The 16.5km …


Proposed Framework For Understanding Information Security Culture And Practices In The Saudi Context, Mohammed Alnatheer, Karen Nelson Dec 2009

Proposed Framework For Understanding Information Security Culture And Practices In The Saudi Context, Mohammed Alnatheer, Karen Nelson

Australian Information Security Management Conference

An examination of Information Security (IS) and Information Security Management (ISM) research in Saudi Arabia has shown the need for more rigorous studies focusing on the implementation and adoption processes involved with IS culture and practices. Overall, there is a lack of academic and professional literature about ISM and more specifically IS culture in Saudi Arabia. Therefore, the overall aim of this paper is to identify issues and factors that assist the implementation and the adoption of IS culture and practices within the Saudi environment. The goal of this paper is to identify the important conditions for creating an information …