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2005

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Full-Text Articles in Physical Sciences and Mathematics

Pachinko Allocation: Dag-Structured Mixture Models Of Topic Correlations, Wei Li, Andrew Mccallum Dec 2005

Pachinko Allocation: Dag-Structured Mixture Models Of Topic Correlations, Wei Li, Andrew Mccallum

Andrew McCallum

Latent Dirichlet allocation (LDA) and other related topic models are increasingly popular tools for summarization and manifold discovery in discrete data. However, LDA does not capture correlations between topics. In this paper, we introduce the pachinko allocation model (PAM), which captures arbitrary, nested, and possibly sparse correlations between topics using a directed acyclic graph (DAG). The leaves of the DAG represent individual words in the vocabulary, while each interior node represents a correlation among its children, which may be words or other interior nodes (topics). PAM provides a flexible alternative to recent work by Blei and Lafferty (2006), which captures ...


Ligand-Based Design Of Dopamine Reuptake Inhibitors : Fuzzy Relational Clustering And 2-D And 3-D Qsar Modleing, Milind Misra Dec 2005

Ligand-Based Design Of Dopamine Reuptake Inhibitors : Fuzzy Relational Clustering And 2-D And 3-D Qsar Modleing, Milind Misra

Dissertations

As the three-dimensional structure of the dopamine transporter (DAT) remains undiscovered, any attempt to model the binding of drug-like ligands to this protein must necessarily include strategies that use ligand information. For flexible ligands that bind to the DAT, the identification of the binding conformation becomes an important but challenging task. In the first part of this work, the selection of a few representative structures as putative binding conformations from a large collection of conformations of a flexible GBR 12909 analogue was demonstrated by cluster analysis. Novel structurebased features that can be easily generalized to other molecules were developed and ...


Dynamic Measuring Tools For Online Discourse, Jeffrey S. Saltz Dec 2005

Dynamic Measuring Tools For Online Discourse, Jeffrey S. Saltz

Dissertations

When evaluating participation within an Asynchronous Learning Network (ALN), current best practices include counting messages and reviewing participant surveys. To understand the impact of more advanced dynamic measurement tools for use within an ALN, a web-based tool, known as iPET (the integrated Participation Evaluation Tool), was created. iPET, which leverages Social Network Analysis and Information Visualization techniques, was then evaluated via an empirical study. This research demonstrates that using a tool such as iPET increases participation within an ALN without increasing facilitator workload. Due to the fact that active online discussion is a key factor in the success of an ...


Study Of Organic Reactions In Pyridinium-Based Ionic Liquids, Ying Xiao Dec 2005

Study Of Organic Reactions In Pyridinium-Based Ionic Liquids, Ying Xiao

Dissertations

Recently, ionic liquids have attracted a lot of attention as novel materials for organic transformations. This is due to their unique properties, which make them suitable substitutes for organic solvents. Most of the available literature is focused on the application of imidazolium-based ionic liquids for organic reactions, while very limited information is available on the application of pyridinium-based ionic liquids.

In this study, two different ionic liquids, 1 -ethyl-pyridinium tetrafluoroborate ([EtPy]+[BF4]-) and 1 -ethyl-pyridinium trifluoroacetate ([EtPy]+[CF3COO]-) have been investigated. Compared to previous reports, the synthetic technique for preparation of Nethyl-pyridinium-based ionic liquids has been improved ...


Development Of Environmentally Benign Microencapsulation With Polymer Microspheres And Liposomes, Baohua Yue Dec 2005

Development Of Environmentally Benign Microencapsulation With Polymer Microspheres And Liposomes, Baohua Yue

Dissertations

Microencapsulation means applying a shell-like coating to encapsulate the contents of interest in a particle form with a size range of few micrometers or below. In this work, aqueous liposome systems and polymer based encapsulation of fine particles in supercritical CO2 were studied. Compared to many other microencapsulation methods, these two methodologies feature reduction/prevention of using organic solvents, making them particularly attractive as green technology.

For polymer microencapsulation, a novel in situ polymerization based process to encapsulate various types of fine particles, include drugs, fire retardant, inorganic nanoparticles, and carbon nanotubes, was developed. In the process, host particles ...


Text Mining With Exploitation Of User's Background Knowledge : Discovering Novel Association Rules From Text, Xin Chen Dec 2005

Text Mining With Exploitation Of User's Background Knowledge : Discovering Novel Association Rules From Text, Xin Chen

Dissertations

The goal of text mining is to find interesting and non-trivial patterns or knowledge from unstructured documents. Both objective and subjective measures have been proposed in the literature to evaluate the interestingness of discovered patterns. However, objective measures alone are insufficient because such measures do not consider knowledge and interests of the users. Subjective measures require explicit input of user expectations which is difficult or even impossible to obtain in text mining environments.

This study proposes a user-oriented text-mining framework and applies it to the problem of discovering novel association rules from documents. The developed system, uMining, consists of two ...


Image Segmentation And Pattern Classification Using Support Vector Machines, Shouxian Cheng Dec 2005

Image Segmentation And Pattern Classification Using Support Vector Machines, Shouxian Cheng

Dissertations

Image segmentation and pattern classification have long been important topics in computer science research. Image segmentation is one of the basic and challenging lower-level image processing tasks. Feature extraction, feature reduction, and classifier design based on selected features are the three essential issues for the pattern classification problem.

In this dissertation, an automatic Seeded Region Growing (SRG) algorithm for color image segmentation is developed. In the SRG algorithm, the initial seeds are automatically determined. An adaptive morphological edge-linking algorithm to fill in the gaps between edge segments is designed. Broken edges are extended along their slope directions by using the ...


Color Image Quality Measures And Retrieval, Yan-Yu Fu Dec 2005

Color Image Quality Measures And Retrieval, Yan-Yu Fu

Dissertations

The focus of this dissertation is mainly on color image, especially on the images with lossy compression. Issues related to color quantization, color correction, color image retrieval and color image quality evaluation are addressed. A no-reference color image quality index is proposed. A novel color correction method applied to low bit-rate JPEG image is developed. A novel method for content-based image retrieval based upon combined feature vectors of shape, texture, and color similarities has been suggested. In addition, an image specific color reduction method has been introduced, which allows a 24-bit JPEG image to be shown in the 8-bit color ...


Quantifying Software Architecture Attributes, Bo Yu Dec 2005

Quantifying Software Architecture Attributes, Bo Yu

Dissertations

Software architecture holds the promise of advancing the state of the art in software engineering. The architecture is emerging as the focal point of many modem reuse/evolutionary paradigms, such as Product Line Engineering, Component Based Software Engineering, and COTS-based software development.

The author focuses his research work on characterizing some properties of a software architecture. He tries to use software metrics to represent the error propagation probabilities, change propagation probabilities, and requirements change propagation probabilities of a software architecture. Error propagation probability reflects the probability that an error that arises in one component of the architecture will propagate to ...


Using Content And Process Scaffolds For Collaborative Discourse In Asynchronous Learning Networks, Irene Wong-Bushby Dec 2005

Using Content And Process Scaffolds For Collaborative Discourse In Asynchronous Learning Networks, Irene Wong-Bushby

Dissertations

Discourse, a form of collaborative learning, is one of the most widely used methods of teaching and learning in the online environment. Particularly, in large courses, discourse needs to be 'structured' to be effective. Historically, technology-mediated learning (TML) research has been inconclusive with often conflicting results. To address this issue, TML research needs greater breadth and depth in pedagogical grounding. The purpose of this research is to build and test an original, technology-mediated, discourse-centered model called the Asynchronous Learning Network Cognitive Discourse Model (ALNCDM) grounded in pedagogy. Cognitive discourse is defined as discourse on conceptual subject matter. The model is ...


Automatic Solar Feature Detection Using Image Processing And Pattern Recognition Techniques, Ming Qu Dec 2005

Automatic Solar Feature Detection Using Image Processing And Pattern Recognition Techniques, Ming Qu

Dissertations

The objective of the research in this dissertation is to develop a software system to automatically detect and characterize solar flares, filaments and Corona Mass Ejections (CMEs), the core of so-called solar activity. These tools will assist us to predict space weather caused by violent solar activity. Image processing and pattern recognition techniques are applied to this system.

For automatic flare detection, the advanced pattern recognition techniques such as Multi-Layer Perceptron (MLP), Radial Basis Function (RBF), and Support Vector Machine (SVM) are used. By tracking the entire process of flares, the motion properties of two-ribbon flares are derived automatically. In ...


Bioinformatics Framework For Genotyping Microarray Data Analysis, Kai Zhang Dec 2005

Bioinformatics Framework For Genotyping Microarray Data Analysis, Kai Zhang

Dissertations

Functional genomics is a flourishing science enabled by recent technological breakthroughs in high-throughput instrumentation and microarray data analysis. Genotyping microarrays establish the genotypes of DNA sequences containing single nucleotide polymorphisms (SNPs), and can help biologists probe the functions of different genes and/or construct complex gene interaction networks. The enormous amount of data from these experiments makes it infeasible to perform manual processing to obtain accurate and reliable results in daily routines. Advanced algorithms as well as an integrated software toolkit are needed to help perform reliable and fast data analysis.

The author developed a MatlabTM based software package ...


Probabilistic Road Map Sampling Strategies For Multi-Robot Motion Planning, Christopher M. Clark Dec 2005

Probabilistic Road Map Sampling Strategies For Multi-Robot Motion Planning, Christopher M. Clark

Computer Science and Software Engineering

This paper presents a Probabilistic Road Map (PRM) motion planning algorithm to be queried within Dynamic Robot Networks—a multi-robot coordination platform for robots operating with limited sensing and inter-robot communication. First, the Dynamic Robot Networks (DRN) coordination platform is introduced that facilitates centralized robot coordination across ad hoc networks, allowing safe navigation in dynamic, unknown environments. As robots move about their environment, they dynamically form communication networks. Within these networks, robots can share local sensing information and coordinate the actions of all robots in the network. Second, a fast single-query Probabilistic Road Map (PRM) to be called within the ...


Afci Quarterly Input – Unlv October 1 Through December 31, 2005, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division Dec 2005

Afci Quarterly Input – Unlv October 1 Through December 31, 2005, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects, activities and objectives of the Transmutation Research Program at the Nuclear Science & Technology Division, Harry Reid Research Center.

The University of Nevada, Las Vegas supports the AFCI through research and development of technologies for economic and environmentally sound refinement of spent nuclear fuel. The UNLV program has four components: infrastructure, international collaboration, student-based research, and management and program support.


Cooperative Conservation: Increasing Capacity Through Community Partnerships -- Interagency Volunteer Program & Cooperative Conservation Program: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees Dec 2005

Cooperative Conservation: Increasing Capacity Through Community Partnerships -- Interagency Volunteer Program & Cooperative Conservation Program: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Get Outdoors Nevada

  • Database now contains 1,807 records, a 15% increase over the last quarter.
  • Website activity increased, recording an average of 38,399 hits per month, with an average of 3,537 pages viewed per month.
  • Inaugural interagency volunteer recognition event held October 28, 2005.
  • Interagency training program (phase 1) scheduled for February 2006 (four sessions).
  • Alternative Workforce Survey completed and delivered to National Park Service.


Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees Dec 2005

Lake Mead National Recreation Area Vegetation Monitoring And Management: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Vegetation Monitoring

Executive Summary

  • Required reports on sticky buckwheat (Eriogonum viscidulum) and threecorner milkvetch (Astragalus geyeri var. triquetrus) to be submitted through appropriate protocols by December 30, 2005
  • Summary report on several other rare plants to be submitted through appropriate protocols by December 30, 2005
  • Invasive perennial pepperweed (also called tall whitetop; Lepidium latifolium) documented and treated by Weed Sentry within Black Canyon, Lake Mojave


Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees Dec 2005

Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Wildlife Monitoring

  • Topsoil replacement monitored at Willow Beach Wastewater Rehabilitation Project
  • Desert tortoise surveys and monitoring conducted for Northshore Road reconstruction projects, and desert tortoise training provided to 9 construction contractors.
  • Field work associated with the project to remove desert tortoise radio transmitters from animals on Mormon Mesa completed.
  • Weekly data processing for Desert Bighorn Sheep monitoring associated with the Hoover Dam Bypass Project continued.
  • Fall field surveys for relict leopard frogs completed (11 sites surveyed); last of this year’s head-started animals released; RLFCT meeting held.
  • Work started on a digital database (GIS) of Peregrine falcon observations.
  • Monthly shorebird surveys conducted ...


Take Pride In America In Southern Nevada: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees Dec 2005

Take Pride In America In Southern Nevada: Quarterly Progress Report, Period Ending December 31, 2005, Margaret N. Rees

Anti-littering Programs

  • Messaging campaign proposal approved by the federal Land Managers.
  • Invitations sent to potential Community Steering Committee members.
  • Project Manager Doug Joslin appointed to new county-wide Southern Nevada Recycling Advisory Committee.
  • Four public service announcements produced by UNLV students.
  • Contract with the Nevada Division of Forestry (NDF) in progress for prison crew site clean-ups.
  • Plan for agency requests for additional dumpsters and/or roll-offs approved by team.


Classifying Malicious Windows Executables Using Anomaly Based Detection, Ronak Sutaria Dec 2005

Classifying Malicious Windows Executables Using Anomaly Based Detection, Ronak Sutaria

Theses

A malicious executable is broadly defined as any program or piece of code designed to cause damage to a system or the information it contains, or to prevent the system from being used in a normal manner. A generic term used to describe any kind of malicious software is Maiware, which includes Viruses, Worms, Trojans, Backdoors, Root-kits, Spyware and Exploits. Anomaly detection is technique which builds a statistical profile of the normal and malicious data and classifies unseen data based on these two profiles.

A detection system is presented here which is anomaly based and focuses on the Windows® platform ...


Model Driven Architecture - A Tool For Enterprise Architecture : A Look At Emergency Response Systems, Ritu Lamba Dec 2005

Model Driven Architecture - A Tool For Enterprise Architecture : A Look At Emergency Response Systems, Ritu Lamba

Theses

Today's fast changing markets and technology drive software industry to deliver high quality enterprise software solutions. The enterprise system architecture should be designed to keep business functions separate from technological implementation to accommodate the fast changing business environment.

In this thesis we have studied the current best practices in defining enterprise architectures and Zachman's framework in particular. We have further examined the Model Driven Architecture (MDA) approach and its application to enterprise architecture definition. MDA separates the business logic from the underlying platform technology and defines a representation model based on precise semantics. Zachman's framework defines a ...


Classifying Rna Secondary Structures Using Support Vector Machines, Prathy Usha Sunkara Dec 2005

Classifying Rna Secondary Structures Using Support Vector Machines, Prathy Usha Sunkara

Theses

In contrast to DNA, RNA prevails as a single strand. As a consequence of small self-complementary regions, RNA commonly exhibits an intricate secondary structure, consisting of relatively short, double helical segments alternated with single stranded regions. The amount of sequence data available is rising rapidly day by day. One of the problems encountered on a specific molecule is finding the relevant data between the massive number of other sequences to be done by reading lists with a short description of all new entries in large databases already existing. One of the main objectives of this work is to take the ...


A New Approach To Feature Extraction For Rna Structure Comparision, Girish Prakash Walawalkar Dec 2005

A New Approach To Feature Extraction For Rna Structure Comparision, Girish Prakash Walawalkar

Theses

In recent years, RNA structural comparison becomes a crucial problem in bioinformatics research. Generally, it is a popular approach for representing the RNA secondary structures with arc-annotation sets. Several methods can be used to compare two RNA structures, such as tree edit distance, longest arc-preserving common subsequence (LAPCS) and stem based alignment. However, these methods may be helpful only for small RNA structures because of their high time complexity. In this thesis, we propose a simplified method to compare two RNA structures in O(mn) time, where m and n are the lengths of the two RNA sequences, respectively. The ...


Environmental Justice Education And Atmospheric Particulate Analysis In Urban Environmental Health Policy Development : Indoor Airborne Particulate Concentrations In Preschools Of Asthmatic Children In Newark, Rita L. Thornton Dec 2005

Environmental Justice Education And Atmospheric Particulate Analysis In Urban Environmental Health Policy Development : Indoor Airborne Particulate Concentrations In Preschools Of Asthmatic Children In Newark, Rita L. Thornton

Dissertations

Analysis suggests that several residential areas in Newark, New Jersey (USA) have Black/African-American and Hispanic populations, which may be "at high risk" with respect to the adverse health effects of particulate air pollution. This study analyzes the community locations and evaluates literature and other available air pollution data for the target communities in the city of Newark. The study focuses on asthma or reactive airway diseases as a target health risk. It also performs data collection on particulate pollutants and levels of trace metals in particulate matter in target communities and schools of preschool children in two of the ...


Facial Feature Representation And Recognition, Chao-Fa Chuang Dec 2005

Facial Feature Representation And Recognition, Chao-Fa Chuang

Dissertations

Facial expression provides an important behavioral measure for studies of emotion, cognitive processes, and social interaction. Facial expression representation and recognition have become a promising research area during recent years. Its applications include human-computer interfaces, human emotion analysis, and medical care and cure.

In this dissertation, the fundamental techniques will be first reviewed, and the developments of the novel algorithms and theorems will be presented later. The objective of the proposed algorithm is to provide a reliable, fast, and integrated procedure to recognize either seven prototypical, emotion-specified expressions (e.g., happy, neutral, angry, disgust, fear, sad, and surprise in JAFFE ...


Semiparametric Approaches For Joint Modeling Of Longitudinal And Survival Data With Time Varying Coefficients, Xiao Song, C.Y. Wang Dec 2005

Semiparametric Approaches For Joint Modeling Of Longitudinal And Survival Data With Time Varying Coefficients, Xiao Song, C.Y. Wang

UW Biostatistics Working Paper Series

We study joint modeling of survival and longitudinal data. There are two regression models of interest. The primary model is for survival outcomes, which are assumed to follow a time varying coefficient proportional hazards model. The second model is for longitudinal data, which are assumed to follow a random effects model. Based on the trajectory of a subject's longitudinal data, some covariates in the survival model are functions of the unobserved random effects. Estimated random effects are generally different from the unobserved random effects and hence this leads to covariate measurement error. To deal with covariate measurement error, we ...


Cu2O(1 1 0) Formation On Co3O4(1 1 0) Induced By Copper Impurity Segregation, S. C. Petitto, Marjorie Langell Dec 2005

Cu2O(1 1 0) Formation On Co3O4(1 1 0) Induced By Copper Impurity Segregation, S. C. Petitto, Marjorie Langell

Marjorie A. Langell Publications

The surface crystal structure of the Co3O4(1 1 0) spinel was characterized by low energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Well-defined LEED diffraction patterns showed an unreconstructed Co3O4(1 1 0) surface in Type A termination, and XPS and Auger indicated the surface to be stoichiometric with octahedral and tetrahedral cation sites occupied by 3+ and 2+ cations, respectively. The experimental lattice parameters of 8.22 Å ± 0.2 Å and 5.50 Å ± 0.2 Å in the (0 0 1) and (1¯ 1 0 ...


Tree Islands In Everglades Landscapes: Current Status, Historical Changes, And Hydrologic Impacts On Population Dynamics And Moisture Relations, First Annual Report, Michael Ross, Steve Oberbauer, Pablo Ruiz, Nilesh Timilsina, Daniel Gomez, Jay Sah, Susanna Stofella, Leonel Sternberg Dec 2005

Tree Islands In Everglades Landscapes: Current Status, Historical Changes, And Hydrologic Impacts On Population Dynamics And Moisture Relations, First Annual Report, Michael Ross, Steve Oberbauer, Pablo Ruiz, Nilesh Timilsina, Daniel Gomez, Jay Sah, Susanna Stofella, Leonel Sternberg

SERC Research Reports

In 2005 we initiated a project designed to better understand tree island structure and function in the Everglades and the wetlands bordering it. Focus was on the raised portions at the upstream end of the islands, where tropical hardwood species adapted to well-drained conditions usually are the most prominent component of the vegetation. The study design is hierarchical, with four levels; in general, a large number of sites is to be surveyed once for a limited set of parameters, and increasingly small sets of islands are to be sampled more intensively, more frequently, and for more aspects of ecosystem function ...


Finite-Dimensional Algebras With Smallest Resolutions Of Simple Modules, Shashidhar Jagadeeshan, Mark Kleiner Dec 2005

Finite-Dimensional Algebras With Smallest Resolutions Of Simple Modules, Shashidhar Jagadeeshan, Mark Kleiner

Mathematics - Faculty Scholarship

Let lamda be an associative ring with identity and with the Jacobson radical r, let mod lamda be the category of finitely generated left lamda-modules, and let lamdaop be the opposite ring of lamda. All modules are left unital modules, and if X is a module then pd X is the projective dimension of X. If lamda is left artinian and M in mod labmda, we denote by P(M) a projective cover of M.


Almost Split Morphisms, Preprojective Algebras And Multiplication Maps Of Maximal Rank, Steven P. Diaz, Mark Kleiner Dec 2005

Almost Split Morphisms, Preprojective Algebras And Multiplication Maps Of Maximal Rank, Steven P. Diaz, Mark Kleiner

Mathematics - Faculty Scholarship

With a grading previously introduced by the second-named author, the multiplication maps in the preprojective algebra satisfy a maximal rank property that is similar to the maximal rank property proven by Hochster and Laksov for the multiplication maps in the commutative polynomial ring. The result follows from a more general theorem about the maximal rank property of a minimal almost split morphism, which also yields a quadratic inequality for the dimensions of indecomposable modules involved.


The Mechanism Of Membrane Targeting Of Human Sphingosine Kinase 1, Robert V. Stahelin, Jeong H. Hwang, Jin-Hahn Kim, Zee-Yong Park, Korey R. Johnson, Lina M. Obeid, Wonhwa Cho Dec 2005

The Mechanism Of Membrane Targeting Of Human Sphingosine Kinase 1, Robert V. Stahelin, Jeong H. Hwang, Jin-Hahn Kim, Zee-Yong Park, Korey R. Johnson, Lina M. Obeid, Wonhwa Cho

Faculty Publications & Research

Sphingosine 1-phosphate is a bioactive sphingolipid that regu- lates cell growth and suppresses programmed cell death. The bio- synthesis of sphingosine 1-phosphate is catalyzed by sphingosine kinase (SK) but the mechanism by which the subcellular localization and activity of SK is regulated in response to various stimuli is not fully understood. To elucidate the origin and structural determi- nant of the specific subcellular localization of SK, we performed biophysical and cell studies of human SK1 (hSK1) and selected mutants. In vitro measurements showed that hSK1 selectively bound phosphatidylserine over other anionic phospholipids and strongly preferred the plasma membrane-mimicking membrane to ...