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2014

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Articles 811 - 840 of 12299

Full-Text Articles in Physical Sciences and Mathematics

Probing The Unfolding And The Stability Of The Last Four Metal Binding Domains Of Wilson Disease Protein Using Circular Dichroism And Novel Spectroscopic Techniques, Ibtesam Yaseen Alja’Afreh Dec 2014

Probing The Unfolding And The Stability Of The Last Four Metal Binding Domains Of Wilson Disease Protein Using Circular Dichroism And Novel Spectroscopic Techniques, Ibtesam Yaseen Alja’Afreh

Dissertations

Wilson disease protein is a copper-transporting P1B type ATPase. It has large N-terminal copper binding domain which is composed of six homologous sub-domains. Each of these six domains is ~72 residues and connected to one another by linking regions of various lengths. They all possess similar ferrodoxin fold, and metal-binding motif, MXCXXC.

The need of having six metal binding domains and the manner in which they are communicating with each other is not well understood. To better understand how the last four metal binding domains function, I pursued a detailed biophysical characterization of these domains. Using molecular biology I …


Lnference On Differences In K Means For Data With Excess Zeros And Detection Limits, Haolai Jiang Dec 2014

Lnference On Differences In K Means For Data With Excess Zeros And Detection Limits, Haolai Jiang

Dissertations

Many data have excess zeros or unobservable values falling below detection limit. For example, data on hospitalization costs incurred by members of a health insurance plan will have zeros for the percentage who did not get sick. Benzene exposure measurements on petroleum re nery workers have some exposures fall below the limit of detection. Traditional methods of inference like one-way ANOVA are not appropriate to analyze such data since the point mass at zero violates typical distribution assumptions.

For testing for equality of means of k distributions, we will propose a likelihood ratio test that accounts for excess zeros or …


Modular Monochromatic Colorings, Spectra And Frames In Graphs, Chira Lumduanhom Dec 2014

Modular Monochromatic Colorings, Spectra And Frames In Graphs, Chira Lumduanhom

Dissertations

Abstract attached as separate document.


Hybrid Meshless Method For Numerical Solution Of Partial Differential Equations, Jeanette Marie Monroe Dec 2014

Hybrid Meshless Method For Numerical Solution Of Partial Differential Equations, Jeanette Marie Monroe

Dissertations

A meshless method for solving partial differential equations (PDEs) which combines the method of fundamental solutions (MFS) and the method of particular solutions (MPS) is formulated and tested. The hybrid method finds a numerical approximation by solving only one system of equations as opposed to the two-stage method of fundamental solutions and method of particular solutions. This new approach, denoted MFS-MPS, one-stage MFS-MPS, or hybrid method, can be applied to a wide variety of PDEs including PDEs with variable coefficients. The MFS-MPS can simplify Helmholtz-type differential operators to Laplacian-type differential operators providing flexibility and simplification to calculating particular solutions and …


Evaluating The Surface Layer Wind Profile In The Wrf, Robert Stephen James Dec 2014

Evaluating The Surface Layer Wind Profile In The Wrf, Robert Stephen James

Theses and Dissertations

The purpose of this thesis is to investigate how the surface vertical wind profile responds to different planetary boundary layer schemes in computer models. Local surface roughness is one of the elements represented in these schemes, and is used when interpolating winds down from the lowest model level to the surface, so this needs to be accurately represented in the model. Computer models rely on one bulk estimate of surface roughness for a given grid point, despite the complexity of surrounding terrain. Data for this research was gathered from local surface observations and computer simulations, which looked at two different …


Compositional Analysis Of Three Clay Artifact Collections From The Southwestern United States, Kathleen R. Kirkham Dec 2014

Compositional Analysis Of Three Clay Artifact Collections From The Southwestern United States, Kathleen R. Kirkham

Theses and Dissertations

This study assessed ways compositional analysis, facilitated by portable X-ray fluorescence technology (PXRF), can be applied in the museum setting to resolve provenance issues and other collections management questions. A major segment of the study evaluated PXRF as a non-invasive geochemical analysis technique to address concerns about whether the resolution of results is sufficient to draw meaningful conclusions. Compositional analysis, mainly facilitated by PXRF, was successfully applied to three clay artifact collections from the southwestern United States. Pottery sherds from Fourmile Ruin were analyzed using PXRF and compared to analyses from invasive wavelength-dispersive XRF and X-ray diffraction techniques. Expanding the …


Synthesis And Characterization Of Complex Molecular Assemblies On Surfaces, Nitesh Madaan Dec 2014

Synthesis And Characterization Of Complex Molecular Assemblies On Surfaces, Nitesh Madaan

Theses and Dissertations

The research presented in this dissertation is focused on the construction of complex molecular structures on planar gold and silicon dioxide surfaces using a variety of surface modification techniques, along with thorough surface characterization at each modification step. The dissertation is structured into six separate chapters. In Chapter 1, an introduction to the importance and implications of molecular level surface modification, commonly employed surface modification methods, and available surface characterization techniques is presented. Chapter 2 shows applications of novel methodologies for the functionalization of gold surfaces using alkane dithiol self-assembled monolayers and thiol-ene click chemistry. The resulting functionalized gold substrates …


Reinforcement Learning Of Distributed Surveillance Plans, Madhavi Chittireddy Dec 2014

Reinforcement Learning Of Distributed Surveillance Plans, Madhavi Chittireddy

Master's Theses

This thesis describes the design and implementation of a Reinforcement Learning algorithm on a camera surveillance model which is used to know the stackelberg strategies of attacker and defender. This reinforcement learning algorithm is compared with the uniform policy and hill climbing algorithms by executing them on a common set of different data files, generated programmatically with various combinations of problem size, location, and orientation transitions as well as rewards of attacker and defender. The comparison includes the time taken to obtain better stackelberg policy and the resulted final pay-off of the defender. This thesis shows that the reinforcement learning …


Replication And Knowledge Production In Empirical Software Engineering Research, Jonathan L. Krein Dec 2014

Replication And Knowledge Production In Empirical Software Engineering Research, Jonathan L. Krein

Theses and Dissertations

Although replication is considered an indispensable part of the scientific method in software engineering, few replication studies are published each year. The rate of replication, however, is not surprising given that replication theory in software engineering is immature. Not only are replication taxonomies varied and difficult to reconcile, but opinions on the role of replication contradict. In general, we have no clear sense of how to build knowledge via replication, particularly given the practical realities of our research field. Consequently, most replications in software engineering yield little useful information. In particular, the vast majority of external replications (i.e., replications performed …


Microchip Thermal Gradient Gas Chromatography, Anzi Wang Dec 2014

Microchip Thermal Gradient Gas Chromatography, Anzi Wang

Theses and Dissertations

Although the airbath oven is a reliable heating method for gas chromatography (GC), resistive heating is needed for higher analytical throughput and on-site chemical analysis because of size, heating rate and power requirements. In the last thirty years, a variety of resistive heating methods were developed and implemented for both benchtop and portable GC systems. Although fast heating rates and low power consumption have been achieved, losses in column efficiency and resolution, complex construction processes and difficulties experienced in recovering damaged columns have also become problematic for routine use of resistively heated columns. To solve these problems, a new resistively …


Framework To Implement Authentication, Authorization And Secure Communications In A Multiuser Collaborative Cax Environment, Francis Mensah Dec 2014

Framework To Implement Authentication, Authorization And Secure Communications In A Multiuser Collaborative Cax Environment, Francis Mensah

Theses and Dissertations

Computer Aided Design (CAD) applications have historically been based on a single user per application architecture. Although this architecture is still popular to date, it does have several drawbacks. First of all the single user CAD architecture inhibits a concurrent engineering design process where several designers can work on the same model simultaneously. This limitation introduces time inefficiency especially when a project involves geographically dispersed designers. A solution to these drawbacks could be a transition from the traditional single user CAD architecture to a multiuser collaborative architecture. Advances in computer networking technologies, especially relating to the Internet, have provided the …


A Covering System With Minimum Modulus 42, Tyler Owens Dec 2014

A Covering System With Minimum Modulus 42, Tyler Owens

Theses and Dissertations

We construct a covering system whose minimum modulus is 42. This improves the previous record of 40 by P. Nielsen.


Using Spectral Analysis To Evaluate Flute Tone Quality, Ron Yorita Dec 2014

Using Spectral Analysis To Evaluate Flute Tone Quality, Ron Yorita

Master's Theses

Many skilled flutists place a high priority on "good" tone quality, or timbre. Timbre can be defined as the audible difference in character that a listener perceives for two notes played at the same pitch. Different timbres are determined by the combination and balance of harmonics that comprise a note. Unlike pitch and rhythm, timbre is difficult to objectively quantify. This project explores (1) how tone quality is described by skilled flutists, (2) whether the harmonic spectrum has some correlation with tone quality, (3) whether certain harmonic spectra are preferred, or considered "good".

Thirty-one flutists ranging from high school students …


Analysis And Optimization Of The Scheffler Solar Concentrator, Simone Alberti Dec 2014

Analysis And Optimization Of The Scheffler Solar Concentrator, Simone Alberti

Master's Theses

The Scheffler reflector is a new solar concentrator design which maintains a fixed focus while only having a single axis tracking mechanism. This design makes the construction and operation of high temperature solar concentrators accessible to developing nations. In this project, I wrote computer simulation codes to better understand the dynamics and the effect of deformation or deviations from ideal conditions in order to define necessary manufacturing and operational tolerances. These tools and knowledge drove the prototyping of new reflector concepts by myself and other students on my team. A fiberglass prototype was able to drive the cost of a …


Towards Intelligent Caring Agents For Aging-In-Place: Issues And Challenges, Di Wang, Budhitama Subagdja, Yilin Kang, Ah-Hwee Tan Dec 2014

Towards Intelligent Caring Agents For Aging-In-Place: Issues And Challenges, Di Wang, Budhitama Subagdja, Yilin Kang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

The aging of the world’s population presents vast societal and individual challenges. The relatively shrinking workforce to support the growing population of the elderly leads to a rapidly increasing amount of technological innovations in the field of elderly care. In this paper, we present an integrated framework consisting of various intelligent agents with their own expertise and responsibilities working in a holistic manner to assist, care, and accompany the elderly around the clock in the home environment. To support the independence of the elderly for Aging-In-Place (AIP), the intelligent agents must well understand the elderly, be fully aware of the …


From Cells To Streets: Estimating Mobile Paths With Cellular-Side Data, Qatar Computing Research Institute, University Of Birmingham, Seattle University Of Washington, Haewoon Kwak Dec 2014

From Cells To Streets: Estimating Mobile Paths With Cellular-Side Data, Qatar Computing Research Institute, University Of Birmingham, Seattle University Of Washington, Haewoon Kwak

Research Collection School Of Computing and Information Systems

Through their normal operation, cellular networks are a repository of continuous location information from their subscribed devices. Such information, however, comes at a coarse granularity both in terms of space, as well as time. For otherwise inactive devices, location information can be obtained at the granularity of the associated cellular sector, and at infrequent points in time, that are sensitive to the structure of the network itself, and the level of mobility of the device. In this paper, we are asking the question of whether such sparse information can help to identify the paths followed by mobile connected devices throughout …


Orchestrating Service Innovation Using Design Moves: The Dynamics Of Fit Between Service And Enterprise It Architectures, Narayan Ramasubbu, Charles Jason Woodard, Sunil Mithas Dec 2014

Orchestrating Service Innovation Using Design Moves: The Dynamics Of Fit Between Service And Enterprise It Architectures, Narayan Ramasubbu, Charles Jason Woodard, Sunil Mithas

Research Collection School Of Computing and Information Systems

Service science perspectives highlight the central role of information technology (IT) in transforming the design and delivery of services. To discern the mechanisms through which IT impacts service innovation, we explore the dynamics of the relationship between enterprise IT and service architectures, and how these dynamics influence the performance of service innovation projects. We conducted six case studies to investigate how firms orchestrated service innovation, focusing on the design of the service architecture and its relationship to enterprise systems. We synthesize the case findings to develop a set of propositions on the antecedents and consequences of fit (or misfit) between …


Measuring Student Performance And Providing Feedback Using Competency Framework, Joelle Elmaleh, Venky Shankararaman Dec 2014

Measuring Student Performance And Providing Feedback Using Competency Framework, Joelle Elmaleh, Venky Shankararaman

Research Collection School Of Computing and Information Systems

A number of Computer Science and Information Systems programs have effectively defined learning outcomes, course level competencies, and conducted assessments at the program level to determine areas for continuous improvement. However, many of these programs do not fully leverage the course competencies during the actual delivery and assessment of the course. This paper presents how course competencies can be used to effectively deliver and assess the course content, and give valuable timely feedback to the students. Using a large first year core course of the BSc (Information Systems Management) program (called Object Oriented Application Development course-OOAD) as an example, this …


Probabilistic Latent Document Network Embedding, Tuan M. V. Le, Hady W. Lauw Dec 2014

Probabilistic Latent Document Network Embedding, Tuan M. V. Le, Hady W. Lauw

Research Collection School Of Computing and Information Systems

A document network refers to a data type that can be represented as a graph of vertices, where each vertex is associated with a text document. Examples of such a data type include hyperlinked Web pages, academic publications with citations, and user profiles in social networks. Such data have very high-dimensional representations, in terms of text as well as network connectivity. In this paper, we study the problem of embedding, or finding a low-dimensional representation of a document network that "preserves" the data as much as possible. These embedded representations are useful for various applications driven by dimensionality reduction, such …


Detecting Camouflaged Applications On Mobile Application Markets, Mon Kywe Su, Yingjiu Li, Huijie Robert Deng, Jason Hong Dec 2014

Detecting Camouflaged Applications On Mobile Application Markets, Mon Kywe Su, Yingjiu Li, Huijie Robert Deng, Jason Hong

Research Collection School Of Computing and Information Systems

Application plagiarism or application cloning is an emerging threat in mobile application markets. It reduces profits of original developers and sometimes even harms the security and privacy of users. In this paper, we introduce a new concept, called camouflaged applications, where external features of mobile applications, such as icons, screenshots, application names or descriptions, are copied. We then propose a scalable detection framework, which can find these suspiciously similar camouflaged applications. To accomplish this, we apply text-based retrieval methods and content-based image retrieval methods in our framework. Our framework is implemented and tested with 30,625 Android applications from the official …


Detecting Flow Anomalies In Distributed Systems, Freddy Chong-Tat Chua, Ee Peng Lim, Bernardo Huberman Dec 2014

Detecting Flow Anomalies In Distributed Systems, Freddy Chong-Tat Chua, Ee Peng Lim, Bernardo Huberman

Research Collection School Of Computing and Information Systems

Deep within the networks of distributed systems, one often finds anomalies that affect their efficiency and performance. These anomalies are difficult to detect because the distributed systems may not have sufficient sensors to monitor the flow of traffic within the interconnected nodes of the networks. Without early detection and making corrections, these anomalies may aggravate over time and could possibly cause disastrous outcomes in the system in the unforeseeable future. Using only coarse-grained information from the two end points of network flows, we propose a network transmission model and a localization algorithm, to detect the location of anomalies and rank …


High-Dimensional Data Stream Classification Via Sparse Online Learning, Dayong Wang, Pengcheng Wu, Peilin Zhao, Yue Wu, Chunyan Miao, Steven C. H. Hoi Dec 2014

High-Dimensional Data Stream Classification Via Sparse Online Learning, Dayong Wang, Pengcheng Wu, Peilin Zhao, Yue Wu, Chunyan Miao, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

The amount of data in our society has been exploding in the era of big data today. In this paper, we address several open challenges of big data stream classification, including high volume, high velocity, high dimensionality, and high sparsity. Many existing studies in data mining literature solve data stream classification tasks in a batch learning setting, which suffers from poor efficiency and scalability when dealing with big data. To overcome the limitations, this paper investigates an online learning framework for big data stream classification tasks. Unlike some existing online data stream classification techniques that are often based on first-order …


Second Order-Response Surface Model For The Automated Parameter Tuning Problem, Aldy Gunawan, Hoong Chuin Lau Dec 2014

Second Order-Response Surface Model For The Automated Parameter Tuning Problem, Aldy Gunawan, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Several automated parameter tuning procedures/configurators have been proposed in order to find the best parameter setting for a target algorithm. These configurators can generally be classified into model-free and model-based approaches. We introduce a recent approach which is based on the hybridization of both approaches. It combines the Design of Experiments (DOE) and Response Surface Methodology (RSM) with prevailing model-free techniques. DOE is mainly used for determining the importance of parameters. A First Order-RSM is initially employed to define the promising region for the important parameters. A Second Order-RSM is then built to approximate the center point as well as …


Midas: Empowering 802.11ac With Multiple-Input Distributed Antenna Systems, Jie Xiong, Karthikeyan Sundaresan, Kyle Jamieson, Mohammad A. Khojastepour, Sampath Rangarajan Dec 2014

Midas: Empowering 802.11ac With Multiple-Input Distributed Antenna Systems, Jie Xiong, Karthikeyan Sundaresan, Kyle Jamieson, Mohammad A. Khojastepour, Sampath Rangarajan

Research Collection School Of Computing and Information Systems

Next generation WLANs (802.11ac) are undergoing a major shift in their communication paradigm with the introduction of multi-user MIMO (MU-MIMO), transitioning from single-user to multi-user communications. We argue that the conventional AP deployment model of co-located antennas as well as their PHY and MAC mechanisms are not designed to realize the complete potential of MUMIMO. We propose to leverage distributed antenna systems (DAS) to empower next generation 802.11ac networks. We highlight the multitude of benefits that DAS brings to MU-MIMO and 802.11ac in general. However, several challenges arise in the process of realizing these benefits in practice, where avoiding client …


An Empirical Study On The Adequacy Of Testing In Open Source Projects, Pavneet Singh Kochhar, Ferdian Thung, David Lo, Julia Lawall Dec 2014

An Empirical Study On The Adequacy Of Testing In Open Source Projects, Pavneet Singh Kochhar, Ferdian Thung, David Lo, Julia Lawall

Research Collection School Of Computing and Information Systems

During software maintenance, testing is crucial to ensure the quality of code as it evolves. With the increasing size and complexity of software, adequate software testing has become increasingly important. Code coverage is an important metric to gauge the effectiveness of test cases and the adequacy of testing. However, what is the coverage level exhibited by large-scale open-source projects? What is the correlation between software metrics and the code coverage of the software?In this study, we investigate the state-of-the-practice of testing by measuring code coverage in open-source software projects. We examine over300 large open-source projects written in Java, coming from …


Pads: Passive Detection Of Moving Targets With Dynamic Speed Using Phy Layer Information, Kun Qian, Chenshu Wu, Zheng Yang, Yunhao Liu, Zimu Zhou Dec 2014

Pads: Passive Detection Of Moving Targets With Dynamic Speed Using Phy Layer Information, Kun Qian, Chenshu Wu, Zheng Yang, Yunhao Liu, Zimu Zhou

Research Collection School Of Computing and Information Systems

Device-free passive detection is an emerging technology to detect whether there exists any moving entities in the area of interests without attaching any device to them. It is an essential primitive for a broad range of applications including intrusion detection for safety precautions, patient monitoring in hospitals, child and elder care at home, etc. Despite of the prevalent signal feature Received Signal Strength (RSS), most robust and reliable solutions resort to finer-grained channel descriptor at physical layer, e.g., the Channel State Information (CSI) in the 802.11n standard. Among a large body of emerging techniques, however, few of them have explored …


A Multi-Method And Multi-Scale Approach For Estimating City-Wide Anthropogenic Heat Fluxes, Winston T. L. Chow, Francisco Salamanca, Matei Gergescu, Alex Mahalov, Jeffrey Milne, Benjamin L. Ruddell Dec 2014

A Multi-Method And Multi-Scale Approach For Estimating City-Wide Anthropogenic Heat Fluxes, Winston T. L. Chow, Francisco Salamanca, Matei Gergescu, Alex Mahalov, Jeffrey Milne, Benjamin L. Ruddell

Research Collection School of Social Sciences

A multi-method approach estimating summer waste heat emissions from anthropogenic activities (QF)was applied for a major subtropical city (Phoenix, AZ). These included detailed, quality-controlled in-ventories of city-wide population density and traffic counts to estimate waste heat emissions frompopulation and vehicular sources respectively, and also included waste heat simulations derived fromurban electrical consumption generated by a coupled building energyeregional climate model (WRF-BEMBEP). These componentQFdata were subsequently summed and mapped through GeographicInformation Systems techniques to enable analysis over local (i.e. census-tract) and regional (i.e.metropolitan area) scales. Through this approach, local mean dailyQFestimates compared reasonablyversus (1.) observed daily surface energy balance residuals from …


Laser-Induced Breakdown Spectroscopy For Analysis Of High Density Methane-Oxygen Mixtures, Matthew Dackman Dec 2014

Laser-Induced Breakdown Spectroscopy For Analysis Of High Density Methane-Oxygen Mixtures, Matthew Dackman

Masters Theses

The applicability of laser-induced breakdown spectroscopy (LIBS) toward greater than atmospheric density combustion diagnostics is examined. Specifically, this involves ascertaining the feasibility of measuring chemical equivalence ratios directly from atomic emission spectra at high density. The need for such measurement arises from the desire to quantify real time, localized combustion performance in weakly mixed flows. Insufficiently mixed flows generally result in unwanted byproducts, possess the propensity for overall combustion instability, and are increasingly likely to experience localized flame extinction.

We simulate methane/oxygen combustion in ambient pressures ranging 1 to 4 atmospheres, demonstrating these results to be analogous to what would …


Gradient-Based Compressive Sensing For Noise Image And Video Reconstruction, Huihuang Zhao, Yaonan Wang, Xiaojiang Peng, Zhijun Qiao Dec 2014

Gradient-Based Compressive Sensing For Noise Image And Video Reconstruction, Huihuang Zhao, Yaonan Wang, Xiaojiang Peng, Zhijun Qiao

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this study, a fast gradient-based compressive sensing (FGB-CS) for noise image and video is proposed. Given a noise image or video, the authors first make it sparse by orthogonal transformation, and then reconstruct it by solving a convex optimisation problem with a novel gradient-based method. The main contribution is twofold. Firstly, they deal with the noise signal reconstruction as a convex minimisation problem, and propose a new compressive sensing based on gradient-based method for noise image and video. Secondly, to improve the computational efficiency of gradient-based compressive sensing, they formulate the convex optimisation of noise signal reconstruction under Lipschitz …


Hydrogeology Of Pumice-Hosted Fens In The Winema-Fremont National Forest, Oregon, Usa, Michael L. Cummings, Jonathan Michael Weatherford, Leslie A. Mowbray Dec 2014

Hydrogeology Of Pumice-Hosted Fens In The Winema-Fremont National Forest, Oregon, Usa, Michael L. Cummings, Jonathan Michael Weatherford, Leslie A. Mowbray

Geology Faculty Publications and Presentations

Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, erosion by ephemeral streams shortly after the eruption disrupted the lateral continuity of the 270 to 300 cm-thick pumice deposit. Co-evolution of the surface- and ground-water systems in a low-relief, low-slope landscape allowed diffuse groundwater discharge from the banks of the evolving stream system. Accumulation of organic material from groundwater dependent ecosystems at these sites of discharge allowed peat deposits to form on gently sloping erosion surfaces cut …