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2005

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Articles 2641 - 2670 of 5573

Full-Text Articles in Physical Sciences and Mathematics

Rhizopine Synthesis – Potential Mediators For Nitrogen Fixation In Legume Plants, Venkat Reddy Guduru Apr 2005

Rhizopine Synthesis – Potential Mediators For Nitrogen Fixation In Legume Plants, Venkat Reddy Guduru

Masters Theses

This research project focused on novel and efficient synthetic approaches of inosamine derivatives (rhizopines). The preparation of specific rhizopines would help elucidate the microbial pathway of rhizopine catabolism and degradation, and determine the role of corresponding genes during nitrogen fixation. We have investigated regio - and stereoselective transformations of myo-inositol derivative 28 utilizing an organostannane as key intermediate towards rhizopine 1a. The synthesis involved several protection and deprotection strategies to control competing reactivities of six hydroxyl groups of myo-inositol. Rhizopine 1a was prepared efficiently as a single isomer in 8 steps and 13% yield by controlling reactions …


Effect Of Antioxidants On Cadmium Induced Oxidative Stress And Signal Transduction, Deepti Goel Apr 2005

Effect Of Antioxidants On Cadmium Induced Oxidative Stress And Signal Transduction, Deepti Goel

Masters Theses

A study was done to establish if reactive oxygen species (ROS) participate in the signal transduction pathway through which cadmium induces gene transcription. Cadmium has become a concern in the health care community in the past few years as evidence suggests that cadmium can induce the development of tumors, influence cell signaling and cause damage to organs, tissue, cells and DNA. The mechanism by which cadmium exerts its action on cellular processes or induces toxicity is however unclear although there is evidence to suggest that ROS play a role. Our laboratory is interested in understanding the mechanisms of differentially regulated …


Walverine: A Walrasian Trading Agent, Shih-Fen Cheng, Evan Leung, Kevin M. Lochner, Kevin O'Malley, Daniel M. Reeves, Julian L. Schvartzman, Michael P. Wellman Apr 2005

Walverine: A Walrasian Trading Agent, Shih-Fen Cheng, Evan Leung, Kevin M. Lochner, Kevin O'Malley, Daniel M. Reeves, Julian L. Schvartzman, Michael P. Wellman

Research Collection School Of Computing and Information Systems

TAC-02 was the third in a series of Trading Agent Competition events fostering research in automating trading strategies by showcasing alternate approaches in an open-invitation market game. TAC presents a challenging travel-shopping scenario where agents must satisfy client preferences for complementary and substitutable goods by interacting through a variety of market types. Michigan's entry, Walverine, bases its decisions on a competitive (Walrasian) analysis of the TAC travel economy. Using this Walrasian model, we construct a decision-theoretic formulation of the optimal bidding problem, which Walverine solves in each round of bidding for each good. Walverine's optimal bidding approach, as well as …


Integrating User Feedback Log Into Relevance Feedback By Coupled Svm For Content-Based Image Retrieval, Steven C. H. Hoi, Michael R. Lyu, Rong Jin Apr 2005

Integrating User Feedback Log Into Relevance Feedback By Coupled Svm For Content-Based Image Retrieval, Steven C. H. Hoi, Michael R. Lyu, Rong Jin

Research Collection School Of Computing and Information Systems

Relevance feedback has been shown as an important tool to boost the retrieval performance in content-based image retrieval. In the past decade, various algorithms have been proposed to formulate relevance feedback in contentbased image retrieval. Traditional relevance feedback techniques mainly carry out the learning tasks by focusing lowlevel visual features of image content with little consideration on log information of user feedback. However, from a long-term learning perspective, the user feedback log is one of the most important resources to bridge the semantic gap problem in image retrieval. In this paper we propose a novel technique to integrate the log …


Transmission Of Environmental And Conservation Knowledge In Andohahela National Park, Mika S. Nagasaki Apr 2005

Transmission Of Environmental And Conservation Knowledge In Andohahela National Park, Mika S. Nagasaki

Independent Study Project (ISP) Collection

Andohahela National Park : Legends and Laws

The legendary forests of Andohahela National Park (N.P.) have long been respected as a source of inspiration and life for the Anosy region in the extreme southeast of Madagascar. Hundreds of years ago, according to various oral traditions, Prince Mana offered himself as a sacrifice in order to quench the drought that brought war and famine to his people, the Tahela (a clan of the Anosy tribe). Zanahary, the Malagasy creator, responded by unleashing the rains and springs in the mountains, which made the land fertile again, and stopped the wars. In gratitude, …


Proactive Caching For Spatial Queries In Mobile Environments, Haibo Hu, Jianliang Xu, Wing Sing Wong, Baihua Zheng, Dik Lun Lee, Wang-Chien Lee Apr 2005

Proactive Caching For Spatial Queries In Mobile Environments, Haibo Hu, Jianliang Xu, Wing Sing Wong, Baihua Zheng, Dik Lun Lee, Wang-Chien Lee

Research Collection School Of Computing and Information Systems

Semantic caching enables mobile clients to answer spatial queries locally by storing the query descriptions together with the results. However, it supports only a limited number of query types, and sharing results among these types is difficult. To address these issues, we propose a proactive caching model which caches the result objects as well as the index that supports these objects as the results. The cached index enables the objects to be reused for all common types of queries. We also propose an adaptive scheme to cache such an index, which further optimizes the query response time for the best …


Natural Loggers: Leaf Cutter Ants As Pests In Northwestern Ecuador, Aaron Honig Apr 2005

Natural Loggers: Leaf Cutter Ants As Pests In Northwestern Ecuador, Aaron Honig

Independent Study Project (ISP) Collection

The biological world is under attack. All across the world in every continent and sub-continent biological diversity is rapidly decreasing (Wilson, 1999). As the human population continues to exponentially increase, especially in Third World countries where biological diversity reaches its peak, countless diverse biological habitats are threatened by accelerating human consumption and the growing needs of growing human populations. In Ecuador, only 1% of the original tropical forest remains, as a result of the accelerating need of viable agricultural tracts for Ecuador’s relatively poor farmers, as well as the unsustainable harvest of valuable hardwood tree species endemic to Ecuador’s primary …


Rotationally Induced Penning Ionization Of Ultracold Photoassociated Helium Dimers, J. Léonard, A. P. Mosk, M. Walhout, M. Leduc Apr 2005

Rotationally Induced Penning Ionization Of Ultracold Photoassociated Helium Dimers, J. Léonard, A. P. Mosk, M. Walhout, M. Leduc

University Faculty Publications and Creative Works

We have studied photoassociation of metastable 23S1 helium atoms near the 23S1-23P2 asymptote by both ion detection in a magneto-optical trap and trap-loss measurements in a magnetic trap. A detailed comparison between the results of the two experiments gives insight into the mechanism of the Penning ionization process. We have identified four series of resonances corresponding to vibrational molecular levels belonging to different rotational states in two potentials. The corresponding spin states become quasi-purely quintet at small interatomic distance, and Penning ionization is inhibited by spin conservation rules. Only a weak rotational coupling is responsible for the contamination by singlet …


Global Optimality Conditions In Mathematical Programming And Optimal Control, Pariwat Pacheenburawaa Apr 2005

Global Optimality Conditions In Mathematical Programming And Optimal Control, Pariwat Pacheenburawaa

Dissertations

We derive new first-order necessary and sufficient optimality conditions characterizing global minimizers in mathematical programming and optimal controlproblems. These conditions are based on level sets of an objective functional and they do not assume special structure of a problem (convexity, linearity, etc.). For a mathematical programming problem of minimization of a smooth functional on some compact convex set with equality nonlinear constraints, we derive first-order optimality conditions in the form of a generalized Lagrange multiplier rule. This rule should hold for any point from the level set of the objective functional corresponding to a global minimizer. We demonstrate that these …


Generalization Issues In Pattern Classification Applied To Speaker Identification, Mame C. Sall Apr 2005

Generalization Issues In Pattern Classification Applied To Speaker Identification, Mame C. Sall

Electrical & Computer Engineering Theses & Dissertations

This thesis is an extension of previous work on speaker identification, but with a primary focus on the generalization performance of patterns classifiers for speaker identification. The goal for all pattern classifiers is to generalize to new data, not just perform well on the training data set. The error on the training data is typically a biased estimate of the generalization error. The training set error tends to be smaller than the generalization error if the model is selected such that it minimizes the training error. Therefore, the training error alone should not be used as a good predictor of …


Rapid Prototyping For The Design Of Virtual Worlds, Prabhu V. Krishnan Apr 2005

Rapid Prototyping For The Design Of Virtual Worlds, Prabhu V. Krishnan

Electrical & Computer Engineering Theses & Dissertations

Development of Virtual Reality (VR) applications is challenging where application developers are required to have expertise in the target VR technologies along with the problem domain expertise. New VR technologies impose a significant learning curve to even the most experienced VR developer. The proposed solution relies on synthesis to automate the migration of a VR application to a new unfamiliar VR platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) was developed, that serves as a superset/model representation of the target virtual world. Input modules were developed to populate the framework with the capabilities of the virtual world …


Kentucky River Watershed Watch Five-Year Data Analysis: 1999 To 2003, Malissa Mcalister, L. Ormsbee Apr 2005

Kentucky River Watershed Watch Five-Year Data Analysis: 1999 To 2003, Malissa Mcalister, L. Ormsbee

Kentucky River Watershed Watch

No abstract provided.


Applying A Simulation-Based Real-Time Decision Making Method To Mass Casualty Scenarios In Hospital Emergency Departments, Fatemah Al-Douli Apr 2005

Applying A Simulation-Based Real-Time Decision Making Method To Mass Casualty Scenarios In Hospital Emergency Departments, Fatemah Al-Douli

Electrical & Computer Engineering Theses & Dissertations

The high possibility of having a mass casualty incident compels hospitals to plan ahead in order to sufficiently provide the healthcare needed to as many casualty victims as possible. The Emergency Rooms (ER) are usually hospitals' main entrance for many casualties. Therefore, the ER in the Children's Hospital of the King's Daughters (CHKD) was selected as the system to be examined. The ER in CHKD, the only specialized pediatric ER in the region, already struggles to handle very high patient arrival rates. Consequently, it is expected that treating a large number of patients surviving within a very short period of …


Image Compression By Vector Quantization Of Dct Coefficients Using A Self-Organizing Neural Network, Kirankumar Boyapati Apr 2005

Image Compression By Vector Quantization Of Dct Coefficients Using A Self-Organizing Neural Network, Kirankumar Boyapati

Electrical & Computer Engineering Theses & Dissertations

Image compression is used to remove different types of redundancies and irrelevant information in an image so that the space required for storing the image is minimized. Conventional transform based techniques remove the redundancies between adjacent pixels and irrelevant information in the image but fail to remove the redundancies between different parts of the image. There are techniques like vector quantization, which take care of the redundant information in different parts of the image, but fail to remove the irrelevant information in the image. In this thesis a new technique for lossy digital image compression is proposed which is a …


Clustering And Hybrid Routing In Mobile Ad Hoc Networks, Lan Wang Apr 2005

Clustering And Hybrid Routing In Mobile Ad Hoc Networks, Lan Wang

Computer Science Theses & Dissertations

This dissertation focuses on clustering and hybrid routing in Mobile Ad Hoc Networks (MANET). Specifically, we study two different network-layer virtual infrastructures proposed for MANET: the explicit cluster infrastructure and the implicit zone infrastructure. In the first part of the dissertation, we propose a novel clustering scheme based on a number of properties of diameter-2 graphs to provide a general-purpose virtual infrastructure for MANET. Compared to virtual infrastructures with central nodes, our virtual infrastructure is more symmetric and stable, but still light-weight. In our clustering scheme, cluster initialization naturally blends into cluster maintenance, showing the unity between these two operations. …


Privacy And Ownership Preserving Of Outsourced Medical Data, Elisa Bertino, Beng Chin Ooi, Yanjiang Yang, Robert H. Deng Apr 2005

Privacy And Ownership Preserving Of Outsourced Medical Data, Elisa Bertino, Beng Chin Ooi, Yanjiang Yang, Robert H. Deng

Research Collection School Of Computing and Information Systems

The demand for the secondary use of medical data is increasing steadily to allow for the provision of better quality health care. Two important issues pertaining to this sharing of data have to be addressed: one is the privacy protection for individuals referred to in the data; the other is copyright protection over the data. In this paper, we present a unified framework that seamlessly combines techniques of binning and digital watermarking to attain the dual goals of privacy and copyright protection. Our binning method is built upon an earlier approach of generalization and suppression by allowing a broader concept …


Providing Efficient Certification Services Against Active Attacks In Ad Hoc Networks, Bo Zhu, Guilin Wang, Zhiguo Wan, Mohan S. Kankanhalli, Feng Bao, Robert H. Deng Apr 2005

Providing Efficient Certification Services Against Active Attacks In Ad Hoc Networks, Bo Zhu, Guilin Wang, Zhiguo Wan, Mohan S. Kankanhalli, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

Most of previous research work in key management can only resist passive attacks, such as dropping the certificate request, and are vulnerable under active attacks, such as returning a fake reply to the node requesting the certification service. In this paper, we propose two algorithms to address both security and efficiency issues of certification services in ad hoc networks. Both of the algorithms can resist active attacks. In addition, simulation results show that, compared to the previous works, our second algorithm is not only much faster in a friendly environment, but it also works well in a hostile environment in …


Keyword Spotting Using Normalization Of Posterior Probability Confidence Measures, Rachna Vijay Vargiya Apr 2005

Keyword Spotting Using Normalization Of Posterior Probability Confidence Measures, Rachna Vijay Vargiya

Theses and Dissertations

Keyword spotting techniques deal with recognition of predefined vocabulary keywords from a voice stream. This research uses HMM based keyword spotting algorithms for this purpose. The three most important components of a keyword detection system are confidence measure, pruning technique and evaluation of results. We suggest that best match for a keyword would be an alignment in which all constituent states have high emission probabilities. Therefore score of even the worst subsequence must also be better than a threshold and a path can be represented by the score of its worst subsequence match. This confidence measure is called Real Fitting. …


Converting Turfgrass To Xeriscape: Evaluating Southern Nevada Water Authority’S “Water Smart Program”, Tom Hudak Apr 2005

Converting Turfgrass To Xeriscape: Evaluating Southern Nevada Water Authority’S “Water Smart Program”, Tom Hudak

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study evaluated the use and effectiveness of the Xeriscape Conversion program, dubbed the “Water Smart Program,” administered by the Southern Nevada Water Authority. The Conversion program is used by five water purveyors throughout Southern Nevada. Because of phenomenal growth in the area, water has become one of the most valuable resources. With its limited availability, conservation has become the logical solution to ever increasing demand. Using empirical data, effectiveness of the program was evaluated in areas such as: water savings after xeriscape conversion; maintenance savings after conversion; the influence of system design on water consumption; and the long term …


Chapter 12 - Part Ii: A New Way Of Thinking About Achieving And Preserving Peace, Raymond Wilson Mar 2005

Chapter 12 - Part Ii: A New Way Of Thinking About Achieving And Preserving Peace, Raymond Wilson

Raymond Wilson

A concise, clearly written, and comprehensive guide to nuclear science and technology. It is especially valuable in providing a scientifically sound foundation for the many social concerns unleashed by nuclear technology.


Transport Coefficients Of Titanium-Doped Sb2te3 Single Crystals., Č. Drašar, M. Steinhart, P. Lošťák, H.-K. Shin, Jeffrey Dyck, C. Uher Mar 2005

Transport Coefficients Of Titanium-Doped Sb2te3 Single Crystals., Č. Drašar, M. Steinhart, P. Lošťák, H.-K. Shin, Jeffrey Dyck, C. Uher

Jeffrey Dyck

Titanium-doped single crystals (cTi=0–2×1020atomscm−3) were prepared from the elements Sb, Ti, and Te of 5N purity by a modified Bridgman method. The obtained crystals were characterized by measurements of the temperature dependence of the electrical resistivity, Hall coefficient, Seebeck coefficient and thermal conductivity in the temperature range of 3–300K. It was observed that with an increasing Ti content in the samples the electrical resistivity, the Hall coefficient and the Seebeck coefficient increase. This means that the incorporation of Ti atoms into the Sb2Te3 crystal structure results in a decrease in the concentration of holes in the doped crystals. For the …


Maximizing The Chances Of A Color Match, Ramin Naimi, Roberto Pelayo Mar 2005

Maximizing The Chances Of A Color Match, Ramin Naimi, Roberto Pelayo

Ramin Naimi

No abstract provided.


The Synthesis Of Chiral Lactones From Racemic -Hydroxyamides Using The Amidase From Brevibacterium Sp. Strain R312, Thomas Goyne, Jennifer Yamaoka, Matthew Pridgeon, Kyle Miner, Stephen Taylor, Min-Ken Liao Mar 2005

The Synthesis Of Chiral Lactones From Racemic -Hydroxyamides Using The Amidase From Brevibacterium Sp. Strain R312, Thomas Goyne, Jennifer Yamaoka, Matthew Pridgeon, Kyle Miner, Stephen Taylor, Min-Ken Liao

Thomas Goyne

No abstract provided.


Using A Microplate Reader To Add A ‘Taste Of Research’ To An Undergraduate Biochemistry Teaching Laboratory, Thomas Goyne, Kasey Hammond, Kevin Mccusker, Jacob Riehm Mar 2005

Using A Microplate Reader To Add A ‘Taste Of Research’ To An Undergraduate Biochemistry Teaching Laboratory, Thomas Goyne, Kasey Hammond, Kevin Mccusker, Jacob Riehm

Thomas Goyne

No abstract provided.


Keys To Successful Learning, Michael J. White, '09, Leah A. Nillas Mar 2005

Keys To Successful Learning, Michael J. White, '09, Leah A. Nillas

Leah A. Nillas

A nationwide push for the use of technology has influenced classroom teaching in the United States. This study examined the use of technology in elementary classrooms. Specific aspects of technology such as PowerPoint and word processing were examined in relation to developing skills in writing. Data from 46 fifth and third grade students as well as self-evaluation interviews with teachers were used to understand the overall comprehensive value of technology in teaching how to write. I expect my results to support previous research findings which assert that using computer technology in writing motivates students to do better work and is …


Additivity Of Information Value In Two-Act Linear Loss Decisions With Normal Priors, Jeffrey Keisler Mar 2005

Additivity Of Information Value In Two-Act Linear Loss Decisions With Normal Priors, Jeffrey Keisler

Jeffrey Keisler

For the two-act linear loss decision problem with normal priors, conditions are derived for which the expected value of perfect information about two independent risks is super-additive in value. Several applications show how a variety of decision problems can reduce to the canonical problem, and how the general results obtained here can be translated simply to prescriptions for specific situations.


The Importance Of Experimental Design In Proteomic Mass Spectrometry Experiments: Some Cautionary Tales, Jeffrey S. Morris, Jianhua Hu, Kevin R. Coombes, Keith A. Baggerly Mar 2005

The Importance Of Experimental Design In Proteomic Mass Spectrometry Experiments: Some Cautionary Tales, Jeffrey S. Morris, Jianhua Hu, Kevin R. Coombes, Keith A. Baggerly

Jeffrey S. Morris

Proteomic expression patterns derived from mass spectrometry have been put forward as potential biomarkers for the early diagnosis of cancer and other diseases. This approach has generated much excitement and has led to a large number of new experiments and vast amounts of new data. The data, derived at great expense, can have very little value if careful attention is not paid to the experimental design and analysis. Using examples from surfaceenhanced laser desorption/ionisation time-of-flight (SELDI-TOF) and matrix-assisted laser desorption–ionisation/time-of-flight (MALDI-TOF) experiments, we describe several experimental design issues that can corrupt a dataset. Fortunately, the problems we identify can be …


Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead-Alloys Coolant Systems: Quarterly Progress Report (01/01/05- 03/31/05), Yitung Chen Mar 2005

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead-Alloys Coolant Systems: Quarterly Progress Report (01/01/05- 03/31/05), Yitung Chen

Transmutation Sciences Materials (TRP)

The goal of the proposed research project is to provide basic understanding of the protective oxide layer behaviors and to develop oxide layer growth models of steels in non-isothermal lead-alloys (lead or lead-bismuth eutectic) coolant systems. It is widely recognized that the corrosiveness of the lead-alloys is a critical obstacle and challenge for which it can be safely used or applied in the nuclear coolant systems. Active oxygen control technique can promote the formation of the “self-healing” oxide films on the structural material surface, drastically reducing steel corrosion and coolant contamination. Many experiments of steels exposed to flowing lead-alloys have …


Measurement Of The Forward-Backward Charge Asymmetry From W→ Production In Pp̅ Collisions At √S=1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Mar 2005

Measurement Of The Forward-Backward Charge Asymmetry From W→Eν Production In Pp̅ Collisions At √S=1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report a measurement of the forward-backward charge asymmetry of electrons from W boson decays in pp̅ collisions at √s =1.96 TeV using a data sample of 170 pb-1 collected by the Collider Detector at Fermilab. The asymmetry is measured as a function of electron rapidity and transverse energy and provides new input on the momentum fraction dependence of the U and d quark parton distribution functions within the proton.


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

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

Get Outdoors Nevada

  • 800+ records now loaded into volunteer database
  • Website launched – getoutdoorsnevada.org
  • 50 new volunteers already recruited through website
  • Program logo developed
  • First interagency event held March 5 – Great American Clean-Up
  • First event featured on national Take Pride In America website
  • Program marketing, public relations, and promotion underway
  • Additional 2005 interagency events identified: April 2 – Red Rock Day at Red Rock Canyon Conservation Area April 15 – Stewardship Saturday at Moapa Valley National Wildlife Refuge June 4 – National