Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Other

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type

Articles 2161 - 2190 of 2496

Full-Text Articles in Physical Sciences and Mathematics

Concept-Based Search Using Parallel Query Expansion, Rahul Rajiv Joshi May 2006

Concept-Based Search Using Parallel Query Expansion, Rahul Rajiv Joshi

Computer Science and Engineering Theses

We address the problem of irrelevant results for short queries on Web search engines. Short queries fail to provide sufficient context to disambiguate possible meanings associated with the search terms resulting in a set of irrelevant pages that the user has to filter through navigation and sometimes examination. First, we predict the potential concept topics, which are the domains for the search terms. This prediction is based on word occurrences and relationships observed in the various domains (categories) of a corpus. Next, we expand the search terms in each of the predicted domains in parallel. We then submit separate queries, …

Go to article

Ubca: A Utility Based Clustering Architecture For Peer-To-Peer Networks, Brent Lagesse May 2006

Ubca: A Utility Based Clustering Architecture For Peer-To-Peer Networks, Brent Lagesse

Computer Science and Engineering Theses

Use of the Peer-to-Peer (P2P) architecture has recently spread in popularity. File sharing and ad hoc networks have contributed to the architecture's usage. P2P generates new challenges in scalability, fairness, and quality of service. Current solutions tend to fall into two main areas: incentives and system design. Incentive-based approaches appeal to the self-interested nature of peers by requiring service to the system in order to access resources. System design includes distributed hash tables and graph-theoretical based designs which have seen some success, but also result in new problems. We introduce a Utility-Based Clustering Architecture, UBCA, designed to address scalability, fairness, …

Go to article

Alternative Architectures For Improving Document Readability, Ankur Bora May 2006

Alternative Architectures For Improving Document Readability, Ankur Bora

Computer Science and Engineering Theses

A number of tools have been developed to improve the readability of documents. These tools assist users to make changes which result in an easy to read document. Most of these tools were developed for users who work independently with little interaction with other users. However, in recent years, because of the proliferation of Internet, there has been increased collaboration between users. A user may need to share his document repositories with others so that both can benefit. Another set of users may work with information from a specific domain. These domains may be located in different geographical areas. Some …

Go to article

Anytime Top-K Queries On Exact And Fuzzy Data, Bhushan P. Chaudhari May 2006

Anytime Top-K Queries On Exact And Fuzzy Data, Bhushan P. Chaudhari

Computer Science and Engineering Theses

Top-k queries on large multi-attribute data sets are fundamental operations in information retrieval and ranking applications. In this thesis, we initiate research on the anytime behavior of top-k algorithms on exact and fuzzy data. In particular given specific topk algorithms we are interested in studying their progress towards identification of the correct result at any point of the algorithms' execution. We adopt a probabilistic approach where we seek to report at any point the scores of the top-k results the algorithm has identified, as well as associate a confidence with this prediction. Such functionality can be a valuable asset when …

Go to article

Towards A Stronger Peer-To-Peer Anonymous System, Arjun R. Nambiar May 2006

Towards A Stronger Peer-To-Peer Anonymous System, Arjun R. Nambiar

Computer Science and Engineering Theses

Anonymous communications systems on the Internet provides protection against eavesdroppers and others that seek to link users with their communications. These systems have many important applications in areas such as law enforcement, intelligence gathering, business privacy, anonymous publishing, and personal privacy. Currently deployed systems rely on a relatively small set of advertised servers to forward messages for the user. These systems can suffer from scalability problems, with potentially large bandwidth and system overhead costs, and the servers themselves can be targets of direct attacks. Peer-to-peer anonymous communications systems, such as Tarzan[1] and MorphMix [2], have been proposed as a way …

Go to article

Multiple Object Tracking Using Particle Filters, Hwangryol Ryu May 2006

Multiple Object Tracking Using Particle Filters, Hwangryol Ryu

Computer Science and Engineering Theses

We describe a novel extension to the Particle filter algorithm for tracking multiple objects. The recently proposed algorithms and the variants for multiple object tacking algorithms estimate multi-modal posterior distributions that potentially represent the multiple peaks (i.e., multiple tracked objects). However, the speci¯c state representation does not demonstrate birth, death and more importantly partial/complete occlusion of the objects. Furthermore, the weakness of the Particle Filter such that the representation may increasingly bias the posterior density estimates toward objects with dominant likelihood makes the multiple object tracking algorithms more di±cult. To circumvent a sample depletion problem and maintain the computational complexity …

Go to article

Investigation Of Techniques To Increase The Scalability Of Graph-Based Data Mining Algorithms., Srilatha Inavolu May 2006

Investigation Of Techniques To Increase The Scalability Of Graph-Based Data Mining Algorithms., Srilatha Inavolu

Computer Science and Engineering Theses

Frequent subgraph pattern recognition and graph-based relational learning have been an emerging area of data mining research with scientific and commercial applications. At the kernel of these algorithms are the computationally-expensive graph and subgraph isomorphism tests. The graph isomorphism problem consists in deciding whether two graphs are isomorphic i.e., whether there is a one-one mapping between the vertices of the two graphs that respects the edge connections. Many graphs will be depicted quite differently but in actuality have the same inherent structure. This leads to the isomorphism problem. The graph isomorphism problem belongs to the class of NP problems and …

Go to article

Relative Clock Drift Rate Based Secure Time Synchronization For Wireless Sensor Networks, Jae Sung Choi May 2006

Relative Clock Drift Rate Based Secure Time Synchronization For Wireless Sensor Networks, Jae Sung Choi

Computer Science and Engineering Theses

Time synchronization is critical issue to many wireless sensor network applications such that target tracking, TDMA radio scheduling, and secure localization. However, the most of existing time synchronization algorithms in wireless sensor networks did not consider malicious attacks in hostile environments. In this thesis, we propose a Relative Clock Drift Rate Based Secure Time Synchronization (RSTS) schemes to address security problems. RSTS alleviates delay attacks and incorrect time stamp transmissions caused by external or internal malicious attackers. We discuss a simple estimation technique to calculate a relative clock drift rate between sender-receiver clocks, because the estimated relative clock drift rate …

Go to article

Towards Optimum Play-Out Buffering Delay In Voice Over Ip, Ruchir Pramod Shende May 2006

Towards Optimum Play-Out Buffering Delay In Voice Over Ip, Ruchir Pramod Shende

Computer Science and Engineering Theses

Voice over Internet Protocol (VoIP) or transmission of real-time voice packets over the Internet is slowly emerging as a cost-effective alternative to the traditional Public Switched Telephone Network (PSTN). However, varying end-to-end delay and packet loss, which are inherent in a packet-switched network like the Internet, lead to relatively lower quality of VoIP calls. The call quality can be improved by adaptively adjusting the play-out buffer at the receiver to reduce the impact of the delay and jitter. A standard play-out strategy uses a weighted moving average of the mean and variance of network delay to adaptively set the play-out …

Go to article

Peroxyl Radical Clocks, Bill Roschek, Keri A. Tallman, Christopher L. Rector, Jason G. Gillmore, Derek A. Pratt, Carlo Punta, Ned A. Porter Apr 2006

Peroxyl Radical Clocks, Bill Roschek, Keri A. Tallman, Christopher L. Rector, Jason G. Gillmore, Derek A. Pratt, Carlo Punta, Ned A. Porter

Faculty Publications

A series of peroxyl radical clocks has been developed and calibrated based on the competition between the unimolecular β-fragmentation (kβ) of a peroxyl radical and its bimolecular reaction with a hydrogen atom donor (kH). These clocks are based on either methyl linoleate or allylbenzene and were calibrated directly with α-tocopherol or methyl linoleate, which have well-established rate constants for reaction with peroxyl radicals (kH-tocopherol = 3.5 × 106 M-1 s-1, kH-linoleate = 62 M-1 s-1). This peroxyl radical clock methodology has been successfully applied to determine inhibition and propagation rate constants ranging from 100 to 107 M-1 s-1.

Go to article

The Elegance Of The Elegant Universe: Unity, Beauty, And Harmony In Brian Greene’S Popularization Of Superstring Theory, Rachel Edford Apr 2006

The Elegance Of The Elegant Universe: Unity, Beauty, And Harmony In Brian Greene’S Popularization Of Superstring Theory, Rachel Edford

EGS Content

The emergence of string theory into popular culture can be seen recent episodes of Joan of Arcadia and the NOVA series based on Brian Greene’s best-selling book, The Elegant Universe. Greene’s book has played a significant role in string theory’s emergence into popular culture. In order to persuade the general public to accept the new and controversial theory of superstrings as a revolutionary scientific theory, Greene carefully constructs his argument in The Elegant Universe, reinforcing the elegance and beauty of string theory and downplaying string theory’s lack of experimental verification. The Elegant Universe itself is an elegantly constructed argument, in …

Go to article

Power And Distortion Optimized Video Coding For Pervasive Computing Applications, Yongfang Liang Apr 2006

Power And Distortion Optimized Video Coding For Pervasive Computing Applications, Yongfang Liang

Computer Science and Engineering Dissertations

This dissertation investigates video encoding schemes for pervasive computing applications that must ensure low power consumption in addition to high compression efficiency. The contribution of the dissertation is the formulation of a theoretical problem that captures the joint optimization of power and distortion in video coding. The study of the complexity distribution of typical video encoders helps to develop a complexity-scalable video encoding architecture that includes several control parameters to adjust the power consumption of the major modules of the encoder. An analytic framework to model, control and optimize the power-rate-distortion is developed, which facilitates the development of optimization schemes …

Go to article

Preparation And Characterization Of Hard Magnetic Nanoparticles, Daren Li Apr 2006

Preparation And Characterization Of Hard Magnetic Nanoparticles, Daren Li

Physics Theses

Hard-magnetic nanoparticles with uniform size distribution have attracted huge attention in the past several years because of their unique magnetic properties and potential for many applications such as high density recording media, exchange-coupled nanocomposite permanent magnets and biomedical applications. In this thesis, preparation and characterization of hard magnetic nanoparticles with different sizes are reported. Monodisperse FePt nanoparticles with face-centered cubic (fcc) structure were synthesized by chemical solution method and particle diameter was tuned from 2 to 15 nm by varying reaction conditions. Monodisperse hard-magnetic FePt nanoparticles with ordered face-centered tetragonal (fct) structure were prepared by the salt-matrix annealing technique. Morphological, …

Go to article

Application Of Software Engineering Best Practices And Principles To Small Development Teams, Miles Phillips Apr 2006

Application Of Software Engineering Best Practices And Principles To Small Development Teams, Miles Phillips

Computer Science and Engineering Theses

The motivation of this thesis comes from the professional experience of the author. Having worked with very small software development teams in various capacities, he realized that significant improvements could be achieved by the application of modern software engineering practices and principles. This paper is the result of researching how the principles and practices promoted by the leading software development authors can be applied to the small development team as they transition from "programming in the small" to "programming in the medium." This paper investigates the best practices and principles in various case studies with the objective to clearly define …

Go to article

The Advantages Of Implementing Software Engineering Process Models, Ricky Don Preuninger Apr 2006

The Advantages Of Implementing Software Engineering Process Models, Ricky Don Preuninger

Computer Science and Engineering Theses

The North Atlantic Treaty Organization Science Committee had discussions on the topic concerned the state of Computer Science. There were worldwide issues with the development of software, the crisis being that software projects did not seem ever to complete. The study group coined the term "software engineering" to be provocative and implying need for software manufacturing to be similar to traditional branches of engineering. In the beginning, individual programmers used whatever means worked to build software. Formal methods of design or programming did not exist. Programmers were never able to give a definitive estimate as to how long a project …

Go to article

A Performance Evaluation Of Alternate Numbering Based Xml Indexing Techniques, Chul Ho Ahn Apr 2006

A Performance Evaluation Of Alternate Numbering Based Xml Indexing Techniques, Chul Ho Ahn

Computer Science and Engineering Theses

Since XML became a standard of representing semi-structured data and exchanging format over the web, the sheer volume of XML data has become larger. While relational database represents data as a structured format, XML represents data in a self-describing way as a hierarchical tree structure. For expediting query processing over XML, many different types of indexing techniques have emerged. We will focus on numbering-based indexing techniques in this thesis. We will present performance comparison according to different XPath queries among three distinct numbering based XML indexing named GENE (Generic numbering based), XISS (Range based numbering), and XACC (Dimension based numbering) …

Go to article

Monitorexplorer: A State-Space Exploration Based Tool To Test Java Monitors Implementations, Vidur Gupta Apr 2006

Monitorexplorer: A State-Space Exploration Based Tool To Test Java Monitors Implementations, Vidur Gupta

Computer Science and Engineering Theses

A monitor is a concurrency construct that encapsulates data. There are many application classes which are written using the Java Monitors and these are difficult to test due to the inherent complexities of the concurrent programs. The key challenge is to be able to trace all possible execution paths and then able to reproduce them for regression testing. Our work explores the state-space of the monitor application. The state space is explored in the depth first fashion. At each state the next possible transition is executed. This process is repeated till a duplicate or invalid state is detected. The key …

Go to article

Bridging Two Grids: The Sam-Grid/Lcg Integration Project, Tummalapalli Sudhamsh Reddy Apr 2006

Bridging Two Grids: The Sam-Grid/Lcg Integration Project, Tummalapalli Sudhamsh Reddy

Computer Science and Engineering Theses

SAM-Grid is an integrated data, job, and information management system. SAM-Grid addresses the distributed computing needs of the Dzero experiment at Fermi National Accelerator Laboratory, Batavia, IL. The system typically relies on SAM-Grid specific services deployed at the remote sites in order to manage the computing and storage resources. Such deployment requires special agreements with each resource provider, and it is a labor intensive process. Some members of the Dzero VO also have access to computing resources through the Large Hydron Collider Computing Grid (LCG) infrastructure. Therefore, Dzero users can enter into resource sharing agreements and deployment of standard middleware …

Go to article

New Developments Of The Deformation Method, Jie Liu Apr 2006

New Developments Of The Deformation Method, Jie Liu

Mathematics Dissertations

New developments of deformation method for grid generation are presented in this work. Theorems for three different cases and different methods for implementing deformation method are presented. One of the new developments is a 3D multi-block moving grid method. In this version, a Poisson equation is solved by finite difference method to get the vector field for moving grid. Special treatment applies to the common boundary of different blocks. Another new development is a numerical method for reconstructing a given differentiable transformations by solving a system of div-curl equation directly formed from each point of the graph. The determinacy and …

Go to article

Creation Of Crm Selection Methodology For The Aerospace & Defense Industry, Reggie Arsenault Feb 2006

Creation Of Crm Selection Methodology For The Aerospace & Defense Industry, Reggie Arsenault

Regis University Student Publications (comprehensive collection)

The Aerospace and Defense Industry is rebounding from one of the worst financial downturns in the history of the market. What has emerged is a realization that the future for Aerospace and Defense manufacturing requires a focus on “services†versus supplying high quality products alone. In order to support such a complex offering of products and services, manufacturing organizations in the Aerospace and Defense Industry must migrate to a customer-centric business structure within their people, processes, and tools. To support the shift, companies must deploy a robust, enterprise, CRM (Customer Relationship Management) technology. The difficulty is in the selection process …

Go to article

Projects That Assist With Content In A Traditional Organic Chemistry Course, John J. Esteb, John R. Magers, Luanne Mcnulty, Anne M. Wilson Jan 2006

Projects That Assist With Content In A Traditional Organic Chemistry Course, John J. Esteb, John R. Magers, Luanne Mcnulty, Anne M. Wilson

Scholarship and Professional Work - LAS

Projects that engage undergraduate students in content-based courses, such as organic chemistry, must relate to the material and provide useful tools for the divergent needs of the students. There are few examples of these types of projects in the literature. Herein, we describe two projects, the reaction notebook and the end-of-semester synthesis activity. Each project is designed to stimulate student ownership of the material and leads to engagement with the content of the course.

Go to article

Development Of The Maryland Shoreline Inventory Methods And Guidelines For Calvert County - Gis Data, Marcia Berman, Harry Berquist, Sharon Killeen, Karen Reay, Karinna Nunez, Tamia Rudnicky, Daniel E. Schatt, David Weiss Jan 2006

Development Of The Maryland Shoreline Inventory Methods And Guidelines For Calvert County - Gis Data, Marcia Berman, Harry Berquist, Sharon Killeen, Karen Reay, Karinna Nunez, Tamia Rudnicky, Daniel E. Schatt, David Weiss

Data

The Center for Coastal Resources Management (CCRM) at the Virginia Institute of Marine Science (VIMS) has generated Shoreline Situation Reports (SSRs) for coastal localities in the state of Maryland. This effort compliments a parallel effort in Virginia by the same group. SSRs were developed by VIMS in the 1970s for Virginia and have been the foundation for shoreline management planning in Tidewater Virginia ever since. CCRM has developed new protocols for collecting, disseminating, and reporting data relevant to shoreline management issues using state of the art mapping and remote sensing techniques. New SSRs are being generated on a county by …

Go to article

Gis Data: Caroline County, Virginia Shoreline Situation Report, Marcia Berman, Harry Berquist, Carl Hershner, Sharon Killeen, Karinna Nunez, Karen Reay, Tamia Rudnicky, David Weiss Jan 2006

Gis Data: Caroline County, Virginia Shoreline Situation Report, Marcia Berman, Harry Berquist, Carl Hershner, Sharon Killeen, Karinna Nunez, Karen Reay, Tamia Rudnicky, David Weiss

Data

The data inventory developed for the Shoreline Situation Reports is based on a three-tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. Hand-held GPS units are used to log features observed. The three tiered shoreline assessment approach divides the shorezone into three regions: 1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes. Three GIS coverages are generated. The car_lubc …

Go to article

Use Of Bootable Linux Cds For The Delivery Of Educational Course Content, Craig Valli Jan 2006

Use Of Bootable Linux Cds For The Delivery Of Educational Course Content, Craig Valli

Research outputs pre 2011

This paper outlines the processes involved in creating and using bootable Linux/Knoppix compact discs (CDs) as a means of delivering course content to students. An outline of experiences in using these CDs to deliver courses in totally on-line mode is also given.

Go to article

Structural Evolution And Vorticity Of Flow During Extrusion And Exhumation Of The Greater Himalayan Slab, Mount Everest Massif, Tibet/Nepal: Implications For Orogen-Scale Flow Partitioning, M. J. Jessup, R. D. Law, M. P. Searle, Mary S. Hubbard Jan 2006

Structural Evolution And Vorticity Of Flow During Extrusion And Exhumation Of The Greater Himalayan Slab, Mount Everest Massif, Tibet/Nepal: Implications For Orogen-Scale Flow Partitioning, M. J. Jessup, R. D. Law, M. P. Searle, Mary S. Hubbard

Geosciences Faculty Publications

The Greater Himalayan Slab (GHS) is composed of a north-dipping anatectic core, bounded above by the South Tibetan detachment system (STDS_ and below by the Main Central thrust zone (MCTZ). Assuming simultaneous movement on the MCTZ and STDS, the GHS can be modelled as a southward-extruding wedge or channel. New insights into extrusion-related flow with the GHS emerge from detailed kinematic and vorticity analyses in the Everest region. At the highest structural levels, mean kinematic vorticity number (Wm) estimates of 0.74-0.91 (c. 45-28% pure shear) were obtained from sheared Tethyan limestone and marble from the Yellow Band on Mount Everest. …

Go to article

You Should Run For Office (Video), Kevin O'Brien, Grace Drake Jan 2006

You Should Run For Office (Video), Kevin O'Brien, Grace Drake

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.

Go to article

Isobaric Analog States As A Tool For Spectroscopy Of Exotic Nuclei, G. V. Rogachev, A. A. Aprahamian, F. D. Becchetti, P. Boutachkov, Y. Chen, G. Chubarian, P. A. Deyoung, A. Fomichev, V. Z. Goldberg, M. S. Golovkov, J. J. Kolata, Yu. Ts. Oganessian, Graham F. Peaslee, M. Quinn, A. Rodin, B. B. Skorodumov, R. S. Slepnev, G. Ter-Akopian, W. H. Trzaska, A. Wohr, R. Wolski Dec 2005

Isobaric Analog States As A Tool For Spectroscopy Of Exotic Nuclei, G. V. Rogachev, A. A. Aprahamian, F. D. Becchetti, P. Boutachkov, Y. Chen, G. Chubarian, P. A. Deyoung, A. Fomichev, V. Z. Goldberg, M. S. Golovkov, J. J. Kolata, Yu. Ts. Oganessian, Graham F. Peaslee, M. Quinn, A. Rodin, B. B. Skorodumov, R. S. Slepnev, G. Ter-Akopian, W. H. Trzaska, A. Wohr, R. Wolski

Faculty Publications

Spectroscopy of neutron rich exotic isotopes via their isobaric analog states (IAS) in less exotic nuclei is discussed. Several different experimental techniques, which can be applied to search for IAS of exotic isotopes, are described. Successful application of these techniques to the studies of heavy helium isotopes7He and 9He led to the observation of unknown IAS in 7Li and 9Li. Spectroscopic information for these states were obtained, and implication of these findings to the structure of 7,9He is considered.

Go to article

On The Existence And Stability Of Carbon -Based Silicon Fullerenes -A Density Functional Theoretic Study, Aravind Srinivasan Dec 2005

On The Existence And Stability Of Carbon -Based Silicon Fullerenes -A Density Functional Theoretic Study, Aravind Srinivasan

Physics Theses

The electronic and geometric properties of silicon-carbon fullerene-like nanostructures with two, four, six, twenty and twenty four carbon atoms on the surface of the Si60 cages by substitution, as well as inside the cage at various symmetry orientations have been studied within the generalized gradient approximation to density functional theory (GGA-DFT). The Perdew-Wang 91 (PW91) functional has been used to treat exchange and correlation energies. Full geometry and spin optimizations have been performed using Gaussian 03 suite of programs and the LANL2DZ basis set. Thus for the silicon atom, the Hay-Wadt pseudopotential with the associated basis set are used for …

Go to article

Oligomeric And Polymeric Bibenzimidazole Based Metal Complexes And Crosslinked Polyethylenimine Based Flame Retardants, Jun Yin Dec 2005

Oligomeric And Polymeric Bibenzimidazole Based Metal Complexes And Crosslinked Polyethylenimine Based Flame Retardants, Jun Yin

Chemistry & Biochemistry Dissertations

In Part I, a simple and mild condensation route for the synthesis of novel bibenzimidazole oligomers and polymers is described using methyl 2,2,2-trichloroacetimidate as a key starting material. The dimer, trimer, tetramer, and polymers of bibenzimidazole were synthesized as a new series of potential conjugated chelating ligands for the metallopolymer studies. The polymers show the maximum absorption at around 400 nm. The optical band gap of the polymer is estimated to be 2.68 eV. In Part II, a series of multinuclear Ru complexes containing di-, tetra-, and octa-RuII centers based on the oligomeric bibenzimidazoles were synthesized and characterized. The species …

Go to article

Monitoring Health By Detecting Drifts And Outliers In Patterns Of An Inhabitant In A Smart Home, Gaurav Jain Dec 2005

Monitoring Health By Detecting Drifts And Outliers In Patterns Of An Inhabitant In A Smart Home, Gaurav Jain

Computer Science and Engineering Theses

The elderly, along with people with disabilities or chronic illness, are most often dependent on some kind of formal or informal care. They are forced to move to a place where they can be cared for. Automatic health monitoring allows them to maintain their independence and continue living at home longer by continuously providing key health and activity information to caregivers. In this thesis, we present a novel technique, called the Health Monitoring System (HMS), which is a data-driven automated monitoring system for detecting changes in the patterns of activities/inactivity, health data and the living environment. HMS classifies these changes …

Go to article

First Prev Next Last