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2009

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Articles 7501 - 7530 of 7678

Full-Text Articles in Physical Sciences and Mathematics

Automated Artice Generation Using The Web, Gaurang Patel Jan 2009

Automated Artice Generation Using The Web, Gaurang Patel

Master's Projects

An article generation application is an intelligent mining engine that looks for web content, then combines and organizes this content in a meaningful way to generate an article. This contrasts with a search engine which generates a list of links to pages containing keywords. This writing project is about such an article generation tool. Our tool generates articles on the topic entered by the user using information available on the web. The articles have well defined sections, each talking about different aspect of the topic.


Evaluations And Enhancements In 802.11n Wlans – Error-Sensitive Adaptive Frame Aggregation, Ken Chan Jan 2009

Evaluations And Enhancements In 802.11n Wlans – Error-Sensitive Adaptive Frame Aggregation, Ken Chan

Master's Projects

IEEE 802.11n is a developing next-generation standard for wireless local area network (LAN). Seamless multimedia traffic connection will become possible with the 802.11n improvement in the Physical and MAC layer. The new 802.11n frame aggregation technique is particularly important for enhancing MAC layer efficiency under high speed wireless LAN. Although the frame aggregation can increase the efficiency in the MAC layer, it does not provide good performance in high BER channels when using large frame aggregation size. An Optimal Frame Aggregation (OFA) technique for AMSDU frame under different BERs in 802.11n WLANs was proposed. However, the suggested algorithm does not …


Improving Web Recommendations Using Web Usage Mining And Web Semantics, Neha Saxena Jan 2009

Improving Web Recommendations Using Web Usage Mining And Web Semantics, Neha Saxena

Master's Projects

This project addresses the topic of improving web recommendations. With the immense increase in the number of websites and web pages on the internet, the issue of suggesting users with the web pages in the area of their interest needs to be addressed as best as possible. Various approaches have been proposed over the years by many researchers and each of them has taken the solution of creating personalized web recommendations a step ahead. Yet, owing to the large possibilities of further improvement, the system proposed in this report takes generating web recommendations one more step ahead. The proposed system …


Visualization Of Tree-Structured Data Through A Multi Touch User Interface, David Andrews Jan 2009

Visualization Of Tree-Structured Data Through A Multi Touch User Interface, David Andrews

Master's Projects

This writing project examines different types of visualizations for tree-structured data sets. Visualizations discussed include link-node diagrams and treemap diagrams. Also discussed is recent innovations with regards to distinguishing multi touch from single touch technology. I explore the requirements needed to build a multi touch table top surface, and describe the process of building one. I then describe my proposed method of visualizing tree-structured data and how it can be implemented using Core Animation technology. I also propose a means of interacting with the data through a multi touch interface, and discuss which gestures can be used to navigate the …


Clustering Algorithm For Enhanced Bibliography Visualization, Sriram Krishnan Jan 2009

Clustering Algorithm For Enhanced Bibliography Visualization, Sriram Krishnan

Master's Projects

A Bibliography is a list of books, publications, journals etc., with details such as authors and references. Visualization could be used as a data analysis tool to represent various types of data, analyze huge chunks of data easily and arrive at interesting results. The idea of this project is to provide a medium which eases the combination of bibliography with visualization. Though there are many sources of bibliographic data like the Digital Bibliography and Library Project (DBLP), Citeseer, Google Scholar, none of these data could be used directly for deducing relations between various entities or for visualizing the relationship between …


Distributed Port Scanning Detection, Himanshu Singh Jan 2009

Distributed Port Scanning Detection, Himanshu Singh

Master's Projects

Conventional Network Intrusion Detection System (NIDS) have heavyweight processing and memory requirements as they maintain per flow state using data structures like linked lists or trees. This is required for some specialized jobs such as Stateful Packet Inspection (SPI) where the network communications between entities are recreated in its entirety to inspect application level data. The downside to this approach is that the NIDS must be in a position to view all inbound and outbound traffic of the protected network. The NIDS can be overwhelmed by a DDoS attack since most of these try and exhaust the available state of …


Synthesis And Characterization Of Organic-Inorganic Colorants, Kiran A V Adiraju Jan 2009

Synthesis And Characterization Of Organic-Inorganic Colorants, Kiran A V Adiraju

Open Access Theses & Dissertations

New colorant materials have been found with the interaction of organic dyes and metal alkoxides. Changes in the hue are observed as indigo dye or thioindigo dyes are combined with the ASB (aluminum tri-secbutoxide), when compared to the original indigo or thioindigo dye, due to the binding and geometry change between dye and metal alkoxide. These dyes are combined with the ASB in two different methods of hydrolysis, namely in the air and in water. Similarly, when TTIP (Titanium tetraisopropoxide) is hydrolyzed using the sol gel process, along with the incorporation of thioindigo dye, hue changes were observed. X-ray diffraction …


Symbiotic Effects Of The Fungus Glomus Sp. On Chromium(Iii), Chromium(Vi), And Lead(Ii) Uptake By Mesquite (Prosopis Sp.): A Novel Method To Remediate Heavy Metals, Jack A. Arias Jan 2009

Symbiotic Effects Of The Fungus Glomus Sp. On Chromium(Iii), Chromium(Vi), And Lead(Ii) Uptake By Mesquite (Prosopis Sp.): A Novel Method To Remediate Heavy Metals, Jack A. Arias

Open Access Theses & Dissertations

The indiscriminate disposal of lead (Pb) and chromium (Cr) containing wastes has resulted in a detrimental impact on environmental health. Lead and Cr are in the EPA priority list due to their degree of toxicity on humans, animals, plants, and other living organisms. The removal of toxic wastes involves technologies that are expensive, sometimes incomplete, and could represent health hazards. In addition, site restoration after contaminant removal encompasses time and technological resources. Phytoremediation, the use of plants alone or associated with microorganisms, represents a potentially cost-effective option in the long term management of contaminated sites. Various plants known as "hyperaccumulators" …


Computational Techniques For Reducing Spectra Of The Giant Planets In Our Solar System, Holly L. Grimes Jan 2009

Computational Techniques For Reducing Spectra Of The Giant Planets In Our Solar System, Holly L. Grimes

Dissertations and Theses

The dynamic atmospheres of Jupiter, Saturn, Uranus, and Neptune provide a rich source of meteorological phenomena for scientists to study. To investigate these planets, scientists obtain spectral images of these bodies using various instruments including the Cooled Mid-Infrared Camera and Spectrometer (COMICS) at the Subaru Telescope Facility at Mauna Kea, Hawaii. These spectral images are two-dimensional arrays of double precision floating point values that have been read from a detector array. Such images must be reduced before the information they contain can be analyzed. The reduction process for spectral images from COMICS involves several steps:

1. Sky subtraction: the …


Third Grade Students' Challenges And Strategies To Solving Mathematical Word Problems, Elizabeth Bernadette Jan 2009

Third Grade Students' Challenges And Strategies To Solving Mathematical Word Problems, Elizabeth Bernadette

Open Access Theses & Dissertations

This project explores the difficulties and challenges that third grade students face solving mathematical word problems. Three students were asked to be participants and share their knowledge on this topic as well as their work. After extensive interviews it was concluded that the challenges of mathematical word problems include but are not limited to the level of reading comprehension, conceptual understanding of mathematical concepts, and the belief that math is a compilation of computations and unexplainable procedures. The participants provided insight as to what strategies are helpful to students. These strategies include group discussion on problem solving strategies, self-assessment, incorporating …


Introduction To Pseudo-Ordered Groups, Maria Dolores Cruz Jan 2009

Introduction To Pseudo-Ordered Groups, Maria Dolores Cruz

Open Access Theses & Dissertations

We will give a definition, examples and basic properties of pseudo-ordered groups. These generalize partially-ordered groups. The pseudo-ordered groups have a compatible pseudo-order relation that may lack transitivity. Unlike partially-ordered groups, our groups can be finite and still admit a non-trivial pseudo-order. We will show necessary and sufficient conditions for a group to have a compatible pseudo-order. We also consider maximal pseudo-orders. We give a definition of a pseudo chain induced by a pseudo-order and characterize all pseudo chains on the group $\mathbb {Z}_{n}.$ We will calculate the number of non-isomorphic pseudo-orders on $\mathbb {Z}_{n}$ for $ n < 24.$


Earth Field Magnetic Resonance Imaging And Paramagnetic Contrast Agents, Saideh Sadat Mortazavi Jan 2009

Earth Field Magnetic Resonance Imaging And Paramagnetic Contrast Agents, Saideh Sadat Mortazavi

Open Access Theses & Dissertations

The goal of this research was to visualize the uptake of copper by plants to aid phyto-remediation research. The hypothesis was that regions of the plant with more copper will have an enhanced NMR signal using copper as a paramagnetic contrast agent.

As the name implies, Earth Field Magnetic Resonance Imaging (EFMRI) spectrometry uses a magnetic field 300,000 times weaker than a 600 MHz Nuclear Magnetic Resonance (NMR) spectrometer. Just like in conventional human MRI, this portable instrument is capable of recording one, two and three dimensional images though the sample size is much smaller.

The enhancement of signal was …


Survey Research On Communication And Language For English Language Learners And Native English Speakers Enrolled In A College Course On Statistical Literacy, Maria Guadalupe Valenzuela Jan 2009

Survey Research On Communication And Language For English Language Learners And Native English Speakers Enrolled In A College Course On Statistical Literacy, Maria Guadalupe Valenzuela

Open Access Theses & Dissertations

The purpose of this study was to examine in what ways language is a factor that affects the learning process of students in an introductory statistics class. This research used a questionnaire survey instrument called: CLASS, Communication, Language And Statistics Survey that was applied to a total of 137 college students from a large southwestern public university, 83 of these students were self-identified as native English speakers (NOELL) and 53 were self-identified as English learner speakers (ELL) and one was dropped. This research found that in statistical instruction, there are some particular differences in behavior and learning process in the …


Pressure Induced Phase Transformation Of Sno2: An Ab Initio Constant Pressure Study, Daniel Tesfai Yehdego Jan 2009

Pressure Induced Phase Transformation Of Sno2: An Ab Initio Constant Pressure Study, Daniel Tesfai Yehdego

Open Access Theses & Dissertations

The behavior of SnO2 under rapid hydrostatic pressures is studied using constant-pressure ab initio simulations. The rutile-type SnO2 gradually transforms into the CaCl2-type structure at 15 GPa. At a pressure of about 20 GPa, a phase transformation into a cubic fluorite-type structure is observed. The orthorhombic Pnma cotunnite-structured phase is observed above 150 GPa. The mechanisms of these phase transformations at the atomistic level are discussed.


Comment On "Generation Of Cold Low Divergent Atomic Beam Of Indium By Laser Ablation", A. Denning, A. Booth, S. Lee, M. Amonson, Scott D. Bergeson Jan 2009

Comment On "Generation Of Cold Low Divergent Atomic Beam Of Indium By Laser Ablation", A. Denning, A. Booth, S. Lee, M. Amonson, Scott D. Bergeson

Faculty Publications

We present measurements of the velocity distribution of calcium atoms in an atomic beam generated using a dual-stage laser back-ablation apparatus. Distributions are measured using a velocity selective Doppler time-of-flight technique. They are Boltzmann-like with rms velocities corresponding to temperatures above the melting point for calcium. Contrary to a recent report in the literature, this method does not generate a subthermal atomic beam.


Spin Dynamics For Wave Packets In Rashba Systems, Bailey C. Hsu, Jean F. Van Huele Jan 2009

Spin Dynamics For Wave Packets In Rashba Systems, Bailey C. Hsu, Jean F. Van Huele

Faculty Publications

We explore spin dynamics for localized wave packets in Rashba systems using spin quantum propagators. We derive exact (one-dimensional) and approximate (two-dimensional) analytic expressions for the propagators and apply them to Gaussian wave packets to obtain localized solutions of systems manifesting Rashba interactions. We observe and describe the evolution of the wave packets. We identify characteristic structures in the wave-packet evolution and look for features with specific spintronics applications such as spin separation and spin accumulation. We discuss the relative importance of those features as a function of the Rashba coupling strength α and the width of the wave packet …


Using A Mathematical Model Of Cadherin-Based Adhesion To Understand The Function Of The Actin Cytoskeleton, J. C. Dallon, Elijah Newren, Marc Hansen Jan 2009

Using A Mathematical Model Of Cadherin-Based Adhesion To Understand The Function Of The Actin Cytoskeleton, J. C. Dallon, Elijah Newren, Marc Hansen

Faculty Publications

The actin cytoskeleton plays a role in cell-cell adhesion but its specific function is not clear. Actin might anchor cadherins or drive membrane protrusions in order to facilitate cell-cell adhesion. Using a mathematical model of the forces involved in cadherin-based adhesion we investigate its possible functions. The immersed boundary method is used to model the cell membrane and cortex with cadherin binding forces added as linear springs. The simulations indicate that cells in suspension can develop normal cell-cell contacts without actin-based cadherin anchoring or membrane protrusions. The cadherins can be fixed in the membrane or free to move and the …


A Strategy For Reducing I/O And Improving Query Processing Time In An Oracle Data Warehouse Environment, Chris Titus Jan 2009

A Strategy For Reducing I/O And Improving Query Processing Time In An Oracle Data Warehouse Environment, Chris Titus

Regis University Student Publications (comprehensive collection)

In the current information age as the saying goes, time is money. For the modern information worker, decisions must often be made quickly. Every extra minute spent waiting for critical data could mean the difference between financial gain and financial ruin. Despite the importance of timely data retrieval, many organizations lack even a basic strategy for improving the performance of their data warehouse based reporting systems. This project explores the idea that a strategy making use of three database performance improvement techniques can reduce I/O (input/output operations) and improve query processing time in an information system designed for reporting. To …


Quc-Tree: Integrating Query Context Information For Efficient Music Retrieval, Jialie Shen, Dacheng Tao, Xuelong Li Jan 2009

Quc-Tree: Integrating Query Context Information For Efficient Music Retrieval, Jialie Shen, Dacheng Tao, Xuelong Li

Research Collection School Of Computing and Information Systems

In this paper, we introduce a novel indexing scheme-query context tree (QUC-tree) to facilitate efficient query sensitive music search under different query contexts. Distinguished from the previous approaches, QUC-tree is a balanced multiway tree structure, where each level represents the data space at different dimensionality. Before the tree structure construction, principle component analysis (PCA) is applied for data analysis and transforming the raw composite features into a new feature space sorted by the importance of acoustic features. The PCA transformed data and reduced dimensions in the upper levels can alleviate suffering from dimensionality curse. To accurately mimic human perception, an …


Integrated Resource Allocation And Scheduling In Bidirectional Flow Shop With Multi-Machine And Cos Constraints, Hoong Chuin Lau, Zhengyi Zhao, Shuzhi Sam Ge Jan 2009

Integrated Resource Allocation And Scheduling In Bidirectional Flow Shop With Multi-Machine And Cos Constraints, Hoong Chuin Lau, Zhengyi Zhao, Shuzhi Sam Ge

Research Collection School Of Computing and Information Systems

An integer programming (IP) model is proposed for integrated resource allocation and operation scheduling for a multiple job-agents system. Each agent handles a specific job-list in a bidirectional flowshop. For the individual agent scheduling problem, a formulation is proposed in continuous time domain and compared with an IP formulation in discrete time domain. Of particular interest is the formulation of the machine utilization function-- both in continuous time and discrete time. Fast heuristic methods are proposed with the relaxation of the machine capacity. For the integrated resource allocation and scheduling problem, a linear programming relaxation approach is applied to solve …


Multiuser Private Queries Over Encrypted Databases, Yanjiang Yang, Feng Bao, Xuhua Ding, Robert H. Deng Jan 2009

Multiuser Private Queries Over Encrypted Databases, Yanjiang Yang, Feng Bao, Xuhua Ding, Robert H. Deng

Research Collection School Of Computing and Information Systems

Searchable encryption schemes allow users to perform keyword-based searches on an encrypted database. Almost all existing such schemes only consider the scenario where a single user acts as both the data owner and the querier. However, most databases in practice do not just serve one user; instead, they support search and write operations by multiple users. In this paper, we systematically study searchable encryption in a practical multiuser setting. Our results include a set of security notions for multiuser searchable encryption as well as a construction which is provably secure under the newly introduced security notions. We also discuss how …


Computing Medoids In Large Spatial Datasets, Kyriakos Mouratidis, Dimitris Papadias, Spiros Papadimitriou Jan 2009

Computing Medoids In Large Spatial Datasets, Kyriakos Mouratidis, Dimitris Papadias, Spiros Papadimitriou

Research Collection School Of Computing and Information Systems

In this chapter, we consider a class of queries that arise in spatial decision making and resource allocation applications. Assume that a company wants to open a number of warehouses in a city. Let P be the set of residential blocks in the city. P represents customer locations to be potentially served by the company. At the same time, P also comprises the candidate warehouse locations because the warehouses themselves must be opened in some residential blocks.


Partially Materialized Digest Scheme: An Efficient Verification Method For Outsourced Databases, Kyriakos Mouratidis, Dimitris Sacharidis, Hwee Hwa Pang Jan 2009

Partially Materialized Digest Scheme: An Efficient Verification Method For Outsourced Databases, Kyriakos Mouratidis, Dimitris Sacharidis, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

In the outsourced database model, a data owner publishes her database through a third-party server; i.e., the server hosts the data and answers user queries on behalf of the owner. Since the server may not be trusted, or may be compromised, users need a means to verify that answers received are both authentic and complete, i.e., that the returned data have not been tampered with, and that no qualifying results have been omitted. We propose a result verification approach for one-dimensional queries, called Partially Materialized Digest scheme (PMD), that applies to both static and dynamic databases. PMD uses separate indexes …


When Is It Beneficial For A Firm To Pursue A Unified Procurement Strategy For Enterprise Software Solutions?, Robert J. Kauffman, Juliana Y. Tsai Jan 2009

When Is It Beneficial For A Firm To Pursue A Unified Procurement Strategy For Enterprise Software Solutions?, Robert J. Kauffman, Juliana Y. Tsai

Research Collection School Of Computing and Information Systems

The underlying structure of the enterprise software marketplace during the past ten years suggests that the arrangements that firms make with respect to the acquisition of such software capabilities will become increasingly concentrated. This article explores the multiple theoretical rationales and business cases for the move to a unified procurement strategy for enterprise software, reflecting some differences in terms of what might be expected from the predictions of the well known move-to-the-middle hypothesis. Our central argument is that a "move-to-the-middle" with more than just a single vendor is the likely outcome in unconsolidated industry markets. In industries experiencing consolidation, firms …


Evaluating Multicore Algorithms On The Unified Memory Model, John E. Savage, Mohammad Zubair Jan 2009

Evaluating Multicore Algorithms On The Unified Memory Model, John E. Savage, Mohammad Zubair

Computer Science Faculty Publications

One of the challenges to achieving good performance on multicore architectures is the effective utilization of the underlying memory hierarchy. While this is an issue for single-core architectures, it is a critical problem for multicore chips. In this paper, we formulate the unified multicore model (UMM) to help understand the fundamental limits on cache performance on these architectures. The UMM seamlessly handles different types of multiple-core processors with varying degrees of cache sharing at different levels. We demonstrate that our model can be used to study a variety of multicore architectures on a variety of applications. In particular, we use …


Toward A More Holistic Approach To The Conservation Management Of Southern Ontario’S Small Protected Areas, Wilfred Gregory Tschirhart Jan 2009

Toward A More Holistic Approach To The Conservation Management Of Southern Ontario’S Small Protected Areas, Wilfred Gregory Tschirhart

Theses and Dissertations (Comprehensive)

Within Southern Ontario’s highly fragmented greater natural ecosystem, there remain numerous relatively small scattered areas which bear at least some resemblance to their former pre-European/Canadian settlement natural ecosystem. In their present state they serve as reservoirs of their particular ecoregion’s indigenous plant and animal species. In proportion to their limited spatial areas, degree of isolation, existing ecological integrity, and long-term ecological carrying capacity they are stores of natural capital, which is beneficial to both nature and society. They co-exist with Southern Ontario’s well developed socioeconomic/cultural system, on whose stewardship their long-term integrity is becoming increasingly dependent, which creates increased environmental …


Mathematical Modeling Of Quantum Dots With Generalized Envelope Functions Approximations And Coupled Partial Differential Equations, Dmytro Sytnyk Jan 2009

Mathematical Modeling Of Quantum Dots With Generalized Envelope Functions Approximations And Coupled Partial Differential Equations, Dmytro Sytnyk

Theses and Dissertations (Comprehensive)

No abstract provided.


Applications Of New Diffusion Models To Barrier Option Pricing And First Hitting Time In Finance, Keang Ly Jan 2009

Applications Of New Diffusion Models To Barrier Option Pricing And First Hitting Time In Finance, Keang Ly

Theses and Dissertations (Comprehensive)

The main focus of this thesis is in the application of a new family of analytical solvable diffusion models to arbitrage-free pricing exotic financial derivatives, such as barrier options. The family of diffusions is the so-called “Drifted Bessel family” having nonlinear (smile-like) local volatility with multiple adjustable parameters. In particular, the drifted Bessel-K diffusion is used to model asset (stock) price processes under a risk-neutral measure whereby discounted asset price are martingales.

Closed-form spectral expansions for barrier option values are derived within the Bessel-K family of models. This follow from the closed-form spectral expansions for the transition probability …


Inuit Qaujimajatuqangit And Adaptive Co-Management: A Case Study Of Narwhal Co-Management In Arctic Bay, Nunavut, Aaron T. Dale Jan 2009

Inuit Qaujimajatuqangit And Adaptive Co-Management: A Case Study Of Narwhal Co-Management In Arctic Bay, Nunavut, Aaron T. Dale

Theses and Dissertations (Comprehensive)

Since 2001 the community of Arctic Bay, located on north-western Baffin Island, in Nunavut, Canada, has been experimenting with a new approach to narwhal management—‘community-based’ narwhal managemet. The new management system has developed some decision-making powers to the local Hunters’ and Trappers’ Organization, who are empowered/required to draft by-laws to govern the hunt. Community-based narwhal management links local, regional, territorial, and national actors and agencies in a co-management arrangement that draws its powers from, and is steered by, the Nunavut Final Agreement (1993), the comprehensive land claims agreement between the Inuit of Nunavut and Her Majesty the Queen in Right …


Laboratory Studies In Chemically Mediated Phosphorus Removal, Rebecca L. Gilmore Jan 2009

Laboratory Studies In Chemically Mediated Phosphorus Removal, Rebecca L. Gilmore

Theses and Dissertations (Comprehensive)

Chemically mediated phosphorus removal, done during wastewater treatment, is an effective means of reducing nutrient loads to sensitive environments. Although this method of treatment is widely used, the mechanism of removal is poorly understood. Moreover, phosphorus regulations for wastewater effluents are moving to concentration ranges of 10-100 μg P/L (total phosphorus). This is much lower than current regulations (∼0.1 ∼0.2 mg P/L as TP) required by municipalities (Takács et al., 2006a; Murthy et al., 2005). The analytical methods for low level phosphate analysis need to be optimized to perform reliably and accurately at these low levels. To accomplish this, absorbance …