Physical Sciences and Mathematics Commons^™

Stable Isotopes In Ecology And Environment โอโซโทปเสถียรในระบบนิเวศและสิ่งแวดล้อม, นรินทร์ บุญตานนท์

Thai Environment

No abstract provided.

การพัฒนาด้านกังหันลมผลิตไฟฟ้า, วิรชัย โรยนรินทร์

Thai Environment

No abstract provided.

โรคร้อนใครคือเหยื่อ?, กัลยา สุนทรวงศ์สกุล

Thai Environment

No abstract provided.

วิวัฒนาการของการตั้งถิ่นฐาน การใช้ประโยชน์ที่ดิน และการขยายตัวของเมืองนครราชสีมา, เสาวนีย์ วิจิตรโกสุม

Thai Environment

No abstract provided.

Rhodium-Catalyzed Hydroboration: Directed Asymmetric Desymmetrization, Judy L. Miska

Department of Chemistry: Dissertations, Theses, and Student Research

Rhodium-catalyzed asymmetric hydroboration in conjunction with directing groups can be used control relative and absolute stereochemistry. Hydroboration has the potential to create new C–C, C–O, and C–N bonds from an intermediate C–B bond with retention of stereochemistry. Desymmetrization resulting in the loss of one or more symmetry elements can give rise to molecular chirality, i.e., the conversion of a prochiral molecule to one that is chiral. Unsaturated amides and esters hold the potential for two-point binding to the rhodium catalyst and have been shown to direct the regiochemistry and impact stereochemistry in asymmetric hydroborations of acyclic β,γ-unsaturated substrates. In …

De Novo Synthesis Of Polyhydroxyl Aminocyclohexanes, Anobick Sar, Sergey Lindeman, William Donaldson

Chemistry Faculty Research and Publications

The syntheses of 12 stereochemically diverse polyhydroxyl aminocyclohexane (“aminocyclitols”) derivatives are described. These short syntheses require 2–5 steps from N-(2,4-cyclohexadien-1-yl)phthalimide, which is prepared in two steps from tricarbonyl(cyclohexadienyl)iron(1+). The relative stereochemistries of the aminocyclitols were assigned by ¹H NMR spectroscopy as well as X-ray diffraction analysis.

Climate Change, Its Effect On Migration Patterns Of The Cackling Goose And White-Fronted Goose In The Willamette Valley, And Implications For Goose Management, Kelly Warren

Environmental Science and Management Professional Master's Project Reports

This thesis considers the question of whether climate change is affecting the migration patterns of geese in the Pacific Flyway, specifically cackling geese (Branta hutchinsii minima) and Pacific white-fronted geese (Anser albifrons frontalis). Ancillary questions that are considered are as follows:

• If global warming is affecting these species, what is the nature of the effects?

• How are the changes affecting the human environment and what can be done about these effects?

In 1994, the majority of the cackler population in the Pacific Flyway began to winter in Oregon's Willamette Valley rather than in their …

Mental Development And Representation Building Through Motivated Learning, Janusz Starzyk, Pawel Raif, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Motivated learning is a new machine learning approach that extends reinforcement learning idea to dynamically changing, and highly structured environments. In this approach a machine is capable of defining its own objectives and learns to satisfy them though an internal reward system. The machine is forced to explore the environment in response to externally applied negative (pain) signals that it must minimize. In doing so, it discovers relationships between objects observed through its sensory inputs and actions it performs on the observed objects. Observed concepts are not predefined but are emerging as a result of successful operations. For the optimum …

Auditing The Defense Against Cross Site Scripting In Web Applications, Lwin Khin Shar, Hee Beng Kuan Tan

Research Collection School Of Computing and Information Systems

Majority attacks to web applications today are mainly carried out through input manipulation in order to cause unintended actions of these applications. These attacks exploit the weaknesses of web applications in preventing the manipulation of inputs. Among these attacks, cross site scripting attack -- malicious input is submitted to perform unintended actions on a HTML response page -- is a common type of attacks. This paper proposes an approach for thorough auditing of code to defend against cross site scripting attack. Based on the possible methods of implementing defenses against cross site scripting attack, the approach extracts all such defenses …

Co-Reranking By Mutual Reinforcement For Image Search, Ting Yao, Tao Mei, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Most existing reranking approaches to image search focus solely on mining “visual” cues within the initial search results. However, the visual information cannot always provide enough guidance to the reranking process. For example, different images with similar appearance may not always present the same relevant information to the query. Observing that multi-modality cues carry complementary relevant information, we propose the idea of co-reranking for image search, by jointly exploring the visual and textual information. Co-reranking couples two random walks, while reinforcing the mutual exchange and propagation of information relevancy across different modalities. The mutual reinforcement is iteratively updated to constrain …

Hybrid Time-Frequency Domain Analysis For Inverter-Fed Induction Motor Fault Detection, T. W. Chua, W. W. Tan, Zhaoxia Wang, C. S. Chang

Research Collection School Of Computing and Information Systems

The detection of faults in an induction motor is important as a part of preventive maintenance. Stator current is one of the most popular signals used for utility-supplied induction motor fault detection as a current sensor can be installed nonintrusively. In variable speeds operation, the use of an inverter to drive the induction motor introduces noise into the stator current so stator current based fault detection techniques become less reliable. This paper presents a hybrid algorithm, which combines time and frequency domain analysis, for broken rotor bar and bearing fault detection. Cluster information obtained by using Independent Component Analysis (ICA) …

Semantics-Preserving Bag-Of-Words Models And Applications, Lei Wu, Steven C. H. Hoi, Nenghai Yu

Research Collection School Of Computing and Information Systems

The Bag-of-Words (BoW) model is a promising image representation technique for image categorization and annotation tasks. One critical limitation of existing BoW models is that much semantic information is lost during the codebook generation process, an important step of BoW. This is because the codebook generated by BoW is often obtained via building the codebook simply by clustering visual features in Euclidian space. However, visual features related to the same semantics may not distribute in clusters in the Euclidian space, which is primarily due to the semantic gap between low-level features and high-level semantics. In this paper, we propose a …

Non-Parametric Kernel Ranking Approach For Social Image Retrieval, Jinfeng Zhuang, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

Social image retrieval has become an emerging research challenge in web rich media search. In this paper, we address the research problem of text-based social image retrieval, which aims to identify and return a set of relevant social images that are related to a text-based query from a corpus of social images. Regular approaches for social image retrieval simply adopt typical text-based image retrieval techniques to search for the relevant social images based on the associated tags, which may suffer from noisy tags. In this paper, we present a novel framework for social image re-ranking based on a non-parametric kernel …

Evaluation Of Protein Backbone Alphabets: Using Predicted Local Structure For Fold Recognition, Kyong Jin Shim

Research Collection School Of Computing and Information Systems

Optimally combining available information is one of the key challenges in knowledge-driven prediction techniques. In this study, we evaluate six Phi and Psi-based backbone alphabets. We show that the addition of predicted backbone conformations to SVM classifiers can improve fold recognition. Our experimental results show that the inclusion of predicted backbone conformations in our feature representation leads to higher overall accuracy compared to when using amino acid residues alone.

Show Me The Numbers: Visual Analytics For Insights, Tin Seong Kam

Research Collection School Of Computing and Information Systems

In this highly volatile and fast-paced financial market, traders and managers working in banking and financial organizations must struggle to cope with large and complex data from multi-sources, that move throughout the market at increasingly high speed. The cost of making poor business and investment decisions is very high. This places great demands on data analysts, who are responsible for providing process information, to support the activities of traders and managers. Static reports and traditional business intelligence tools simply cannot keep up with a market that is changing on a second-to-second basis. By the time the traders and bankers have …

Virtualization For Computational Scientists, George K. Thiruvathukal, Konrad Hinsen, Joseph P. Kaylor, Konstantin Läufer

Computer Science: Faculty Publications and Other Works

Virtualization lets you carve your computer into slices, allowing for great experimentation with different operating systems, tools, and techniques.

Designing Software Product Lines For Testability, Isis Cabral

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Software product line (SPL) engineering offers several advantages in the development of families of software products such as reduced costs, high quality and a short time to market. A software product line is a set of software intensive systems, each of which shares a common core set of functionalities, but also differs from the other products through customization tailored to fit the needs of individual groups of customers. The differences between products within the family are well-understood and organized into a feature model that represents the variability of the SPL. Products can then be built by generating and composing features …

The Dickey Bird Scientists Take Charge: Science, Policy, And The Spotted Owl, Thomas R. Wellock

History Faculty Scholarship

In 1992, the Forest Service adopted a new operating policy, Ecosystem Management, which minimized the agency's timber production goals in favor of a more ecologically balanced view of its responsibilities. In explaining this shift, scholars have dismissed the possibility of internal reform, arguing that the Service could not change without irresistible external pressure from environmental activists and new public values supporting biodiversity. Viewing the Service's shift through the lens of the spotted owl controversy, however, demonstrates the important role agency culture played in instigating bureaucratic change. The Service's evolution stemmed from the rising influence of its scientists in policy formation. …

Boundary Type Quadrature Formulas Over Axially Symmetric Regions, Tian-Xiao He

Scholarship

A boundary type quadrature formula (BTQF) is an approximate integration formula with all its of evaluation points lying on the Boundary of the integration domain. This type formulas are particularly useful for the cases when the values of the integrand functions and their derivatives inside the domain are not given or are not easily determined. In this paper, we will establish the BTQFs over sonic axially symmetric regions. We will discuss time following three questions in the construction of BTQFs: (i) What is the highest possible degree of algebraic precision of the BTQF if it exists? (ii) What is the …

Assessing The Short-Term Forecast Capability Of Nonstandardized Surface Observations Using The National Digital Forecast Database (Ndfd), Joby Hilliker, G Akasapu, G S. Young

Earth & Space Sciences Faculty Publications

The number of surface observations from nonstandardized networks across the United States has appreciably increased the last several years. Automated Weather Services, Inc. (AWS), maintains one example of this type of network offering nonstandardized observations for similar to 8000 sites. The present study assesses the utility of such a network to improve short-term (i.e., lead times < 12 h) National Digital Forecast Database (NDFD) forecasts for three parameters most relevant to the energy industry-temperature, dewpoint, and wind speed. A 1-yr sample of 13 AWS sites is chosen to evaluate the magnitude of forecast improvement (skill) and influence of physical location (siting) on such improvements. Hourly predictions are generated using generalized additive modeling (GAM)-a nonlinear statistical equation incorporating a predetermined set of the most significant AWS and NDFD predictors. Two references are used for comparison: (i) persistence climatology (PC) forecasts and (ii) NDFD forecasts calibrated to the AWS sites (CNDFD). The skill, measured via the percent improvement (reduction) in the mean absolute error (MAE), of forecasts generated by the study's technique (CNDFD+) is comparable (< 5%) to PC for lead times of 1-3 h for dewpoint and wind speed. Skill relative to PC slowly increases with lead time, with temperature exhibiting the greatest relative-to-PC skill (similar to 30% at 12 h). When compared to baseline CNDFD forecasts, the MAE of the generated CNDFD+ forecasts is reduced 65% for temperature and dewpoint at the 1-h lead time. An exponential drop in improvement occurs for longer lead times. Wind speed improvements are notably less, with little skill (< 5%) demonstrated for forecasts beyond 4 h. Overall, CNDFD+ forecasts have the greatest accuracy relative to CNDFD and PC for the middle (3-7 h) lead times tested in the study. Variations in CNDFD+ skill exist with respect to AWS location. Tested stations located in complex terrain generally exhibit greater skill relative to CNDFD than the 13-station average for temperature (and, to a lesser degree, dewpoint). Relative to PC, however, the same subset of stations exhibits skill below the 13-station average. No conclusive relationship can be made between CNDFD+ skill and the sample stations located near water.

Computational Modeling Of Biological Neural Networks On Gpus: Strategies And Performance, Byron Galbraith

Master's Theses (2009 -)

Simulating biological neural networks is an important task for computational neuroscientists attempting to model and analyze brain activity and function. As these networks become larger and more complex, the computational power required grows significantly, often requiring the use of supercomputers or compute clusters. An emerging low-cost, highly accessible alternative to many of these resources is the Graphics Processing Unit (GPU) - specialized massively-parallel graphics hardware that has seen increasing use as a general purpose computational accelerator thanks largely due to NVIDIA's CUDA programming interface. We evaluated the relative benefits and limitations of GPU-based tools for large-scale neural network simulation and …

Order-Dependent Mappings: Strong-Coupling Behavior From Weak-Coupling Expansions In Non-Hermitian Theories, Jean Zinn-Justin, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

A long time ago, it has been conjectured that a Hamiltonian with a potential of the form x ²+ivx ³, v real, has a real spectrum. This conjecture has been generalized to a class of the so-called PT symmetric Hamiltonians and some proofs have been given. Here, we show by numerical investigation that the divergent perturbation series can be summed efficiently by an order-dependent mapping (ODM) in the whole complex plane of the coupling parameter v ², and that some information about the location of level-crossing singularities can be obtained in this way. Furthermore, we discuss to …

Women Belonging In The Social Worlds Of Graduate Mathematics, Abbe H. Herzig

The Mathematics Enthusiast

The participation of women in post-graduate mathematics still lags substantially behind that of men. Drawing upon sociocultural theories of learning, I argue that success in graduate school necessitates learning mathematical content, participating in mathematical practices, and developing a sense of belonging in mathematics. Using an institutional ethnography approach, I interviewed 12 women graduate students from three mathematics departments in the U.S. to document their experiences within the social relations of graduate mathematics. They described both intrinsic and extrinsic obstacles to belonging, including a tension between their desire to belong and their needs to distance themselves from what they perceived to …

Accelerating Image Feature Comparisons Using Cuda On Commodity Hardware, Amy Apon, Seth Warn, Wesley Emeneker, John Gauch, Jackson Cothren

Publications

Given multiple images of the same scene, image registration is the process of determining the correct transformation to bring the images into a common coordinate system—i.e., how the images fit together. Feature based registration applies a transformation function to the input images before performing the correlation step. The result of that transformation, also called feature extraction, is a list of significant points in the images, and the registration process will attempt to correlate these points, rather than directly comparing the input images.

Nonparametric Testing For Asymmetric Information, Liangjun Su, Martin Spindler

Research Collection School Of Economics

Asymmetric information is an important phenomenon in many markets and in particular in insurance markets. Testing for asymmetric information has become a very important issue in the literature in the last two decades. Almost all testing procedures that are used in empirical studies are parametric, which may yield misleading conclusions in the case of misspecification of either functional or distributional relationships among the variables of interest. Motivated by the literature on testing conditional independence, we propose a new nonparametric test for asymmetric information which is applicable in a variety of situations. We demonstrate the test works reasonably well through Monte …

Symmetries Of The Central Vestibular System: Forming Movements For Gravity And A Three-Dimensional World, Gin Mccollum, Douglas Hanes

Mathematics and Statistics Faculty Publications and Presentations

Intrinsic dynamics of the central vestibular system (CVS) appear to be at least partly determined by the symmetries of its connections. The CVS contributes to whole-body functions such as upright balance and maintenance of gaze direction. These functions coordinate disparate senses (visual, inertial, somatosensory, auditory) and body movements (leg, trunk, head/neck, eye). They are also unified by geometric conditions. Symmetry groups have been found to structure experimentally-recorded pathways of the central vestibular system. When related to geometric conditions in three-dimensional physical space, these symmetry groups make sense as a logical foundation for sensorimotor coordination.

Water Erosion Hazard Assessment Of The Lort And Young Rivers Catchment, Karen Holmes, John Andrew Simons, B Marillier, N Callow, Paul Galloway

Resource management technical reports

No abstract provided.

Chaos In Physics And Recurrence In Arithmetic Sets, Jean Dayantis

The Mathematics Enthusiast

After briefly recalling the concepts of recurrence and chaos in physics, the recurrence properties of arithmetic sets are examined following Gauss’ method, as exposed in part three of his Disquisitiones Arithmeticae. This problem in number theory is related to the physical problem of recurrence in deterministic chaos. Most possible forms of moduli are examined in detail with respect to their recurrence properties, for application to the generalized Bernoulli mapping. The emphasis is put on period lengths, rather than on congruences. In an annex the recurrence properties of Arnold’s cat map are briefly examined.

Rehearsal Or Reorganization: Two Patterns Of Literacy Strategy Use In Secondary Mathematics Classes, Anne Adams

The Mathematics Enthusiast

This study presents two critical cases illustrating distinct patterns in teachers' use of literacy strategies in secondary mathematics classes. The cases are part of a professional development project designed to enhance teachers' pedagogical skills by developing content literacy strategies for use in secondary mathematics and science classrooms. Teachers' beliefs about teaching mathematics, their uses of writing and vocabulary development strategies, and goals for student learning were examined via interviews, classroom observations, reflections on teaching, and teacher posts to an online discussion forum. Results show patterns of literacy strategy use were related to teachers' views of pedagogy and of mathematics. Ned, …

Short-Chain Carboxylic Acids From Gray Catbird (Dumetella Carolinensis) Uropygial Secretions Vary With Testosterone Levels And Photoperiod, Rebecca J. Whelan, Tera C. Levin, Mary C. Garvin

Faculty & Staff Scholarship

The uropygial gland of birds produces secretions that are important in maintaining the health and structural integrity of feathers. Non-volatile components of uropygial secretions are believed to serve a number of functions including waterproofing and conditioning the feathers. Volatile components have been characterized in fewer species, but are particularly interesting because of their potential importance in olfactory interactions within and across species. We used solid-phase microextraction headspace sampling with gas chromatography-mass spectrometry to detect and identify volatiles in uropygial secretions of gray catbirds (Dumetella carolinensis), a North American migratory bird. We consistently detected the following carboxylic acids: acetic, propanoic, 2-methylpropanoic, …