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2008

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Articles 991 - 1020 of 1335

Full-Text Articles in Computer Sciences

Concept Detection: Convergence To Local Features And Opportunities Beyond, Shih-Fu Chang, Junfeng He, Yu-Gang Jiang, Elie El Khoury, Chong-Wah Ngo, Akira Yanagawa, Eric Zavesky Jan 2008

Concept Detection: Convergence To Local Features And Opportunities Beyond, Shih-Fu Chang, Junfeng He, Yu-Gang Jiang, Elie El Khoury, Chong-Wah Ngo, Akira Yanagawa, Eric Zavesky

Research Collection School Of Computing and Information Systems

No abstract provided.


Management Framework For Hybrid Wireless Networks, Chong Shen Jan 2008

Management Framework For Hybrid Wireless Networks, Chong Shen

Theses

The objective of the Hybrid Wireless Network with dedicated Relay Nodes (HWN*) architecture is to interface the Base Station (BS) Oriented Mobile Network (BSON) and the 802.fix based Mobile Ad hoc Wireless Network (MANET) so that one system can be utilised as an alternative radio access network for data transmissions, while the incorporation of Relay Nodes (RN) is to extend the communication coverage, optimise medium resource sharing, increase spatial reuse opportunity, stabilise MANET link and create more micro-cells. The HWN* keeps the existing cellular infrastructure and a Mobile Terminal (MT) can borrow radio resources from other cells via secure multi-hop …


Nonlinear Random Response Of Large-Scale Sparse Finite Element Plate Bending Problems, Swati Chokshi Jan 2008

Nonlinear Random Response Of Large-Scale Sparse Finite Element Plate Bending Problems, Swati Chokshi

Civil & Environmental Engineering Theses & Dissertations

Acoustic fatigue is one of the major design considerations for skin panels exposed to high levels of random pressure at subsonic/supersonic/hypersonic speeds. The nonlinear large deflection random response of the single-bay panels aerospace structures subjected to random excitations at various sound pressure levels (SPLs) is investigated. The nonlinear responses of plate analyses are limited to determine the root-mean-square displacement under uniformly distributed pressure random loads. Efficient computational technologies like sparse storage schemes and parallel computation are proposed and incorporated to solve large-scale, nonlinear large deflection random vibration problems for both types of loading cases: (1) synchronized in time and (2) …


Rapid Prototyping For Virtual Environments, Emre Baydogan Jan 2008

Rapid Prototyping For Virtual Environments, Emre Baydogan

Electrical & Computer Engineering Theses & Dissertations

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


Comparison Of Rectangular And Cylindrical Fdtd Representations On A Ring Resonator Problem, Funda Akleman, Levent Sevgi̇ Jan 2008

Comparison Of Rectangular And Cylindrical Fdtd Representations On A Ring Resonator Problem, Funda Akleman, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is to discuss rectangular and cylindrical representations of finite-difference time-domain (FDTD) method over characteristic tests and comparisons. A ring resonator is chosen as a canonical structure and modeled with both rectangular- and cylindrical-FDTD packages. Calibration against analytical exact solution derived in terms of cylindrical Bessel functions is also performed. It is shown that rectangular-FDTD with periodic boundary condition, where the computation domain is reduced, can also be applied in modeling circular structures.


Functorial Coalgebraic Logic: The Case Of Many-Sorted Varieties, Alexander Kurz, Daniela Petrişan Jan 2008

Functorial Coalgebraic Logic: The Case Of Many-Sorted Varieties, Alexander Kurz, Daniela Petrişan

Engineering Faculty Articles and Research

Following earlier work, a modal logic for T-coalgebras is a functor L on a suitable variety. Syntax and proof system of the logic are given by presentations of the functor. This paper makes two contributions. First, a previous result characterizing those functors that have presentations is generalized from endofunctors on one-sorted varieties to functors between many-sorted varieties. This yields an equational logic for the presheaf semantics of higher-order abstract syntax. As another application, we show how the move to functors between many-sorted varieties allows to modularly combine syntax and proof systems of different logics. Second, we show how to associate …


Volume And Cost Implications Of Product Portfolio Complexity, Mark A. Jacobs Jan 2008

Volume And Cost Implications Of Product Portfolio Complexity, Mark A. Jacobs

MIS/OM/DS Faculty Publications

Business leaders are concerned about the impacts of increasing levels of product portfolio complexity since many sense that complexity related costs such as order management, procurement, and inventory threaten to undermine operational efficiencies and consume profits. Even so, managers do not fully understand the extent and breadth of the impacts of product portfolio complexity. A more complete understanding of the operational effects of product portfolio complexity is lacking partially because researchers have not yet offered a robust theoretical perspective or studied it in a focused controlled way; until now. Herein, measures of product portfolio complexity are developed and related to …


Games, Robots, And Robot Games: Complementary Contexts For Introductory Computing Education, Dianna Xu, Doug Blank, Deepak Kumar Jan 2008

Games, Robots, And Robot Games: Complementary Contexts For Introductory Computing Education, Dianna Xu, Doug Blank, Deepak Kumar

Computer Science Faculty Research and Scholarship

Using games to teach introductory computing courses provides another context with which to exploring the possible attraction, retention, and education of a new generation of computer science (CS) students. At Bryn Mawr College, we have been actively exploring these contexts and have identified four that have great promise for use in teaching introductory computing courses: visualization, multimedia, robotics, and, most recently, games. We are currently using and analysing robots and have some preliminary results. We believe that much of what we have learned in using robots in the classroom can be applied to the other contexts, especially gaming. In addition, …


Generation Of High-Repetition-Rate Pulses Utilizing Cascaded Single Mode Fiber And Semiconductor Optical Amplifier, Jianwei Wu, Hai-Bo Bao Jan 2008

Generation Of High-Repetition-Rate Pulses Utilizing Cascaded Single Mode Fiber And Semiconductor Optical Amplifier, Jianwei Wu, Hai-Bo Bao

Turkish Journal of Electrical Engineering and Computer Sciences

To generate high-repetition-rate optical pulses, a novel and simple device is demonstrated, in which the cascaded single mode fiber (SMF) with negative third order dispersion and semiconductor optical amplifier (SOA) are adopted. Numerical research results show that let an optical pulse with center wavelength in zero dispersion wavelength of optical fiber transit in SMF for generating an oscillation pulse. Subsequently, the followed SOA is provided for amplification. As a consequence, the high-repetition-rate optical pulses can be obtained.


A Study On The Reliability Of Polyester Insulators Blended With Borax, Aysel Ersoy, Yasi̇n Özcelep, Ayten Kuntman Jan 2008

A Study On The Reliability Of Polyester Insulators Blended With Borax, Aysel Ersoy, Yasi̇n Özcelep, Ayten Kuntman

Turkish Journal of Electrical Engineering and Computer Sciences

Tracking is the main factor which limits the safe working electric stress of insulation in power system applications. Polymer samples have been tested in laboratory conditions according to ASTM D2303 on accelerated inclined plane tracking test. In this paper, a model based on improved Weibull statistics is proposed for estimating the breakdown time of polymeric insulating materials with borax. The confidence intervals of the Weibull shape parameter and the Weibull scale parameter are determined for the borax concentration values using the Weibull 7++ program.


Relative Searching Using An Ordered Token List, Anthony Rosequist Jan 2008

Relative Searching Using An Ordered Token List, Anthony Rosequist

Inquiry: The University of Arkansas Undergraduate Research Journal

Many organizations have large amounts of information, such as consumer data, that need to be processed. Traditional searching algorithms only attempt to find exact matches to particular queries. This is undesirable when data are missing, outdated, or inaccurate. Therefore, a new type of search must be developed to locate records that are considered "interesting" to the user. This research paper examines past attempts to solve this problem and explores a new method involving ordered token lists to achieve this goal. The algorithm was developed, implemented, tested, and optimized.


Application Of Computer Simulation Modeling To Evaluate Business Continuity Plans, Jose Francisco Molina Garcia Plaza Jan 2008

Application Of Computer Simulation Modeling To Evaluate Business Continuity Plans, Jose Francisco Molina Garcia Plaza

CCAC Theses and Dissertations

Business continuity plans (BCP) help organizations plan for and withstand the occurrence of unexpected events that interrupt the normal operation of business. Managers typically develop several alternate plans to minimize the business impact of unexpected events. The problem for decision makers is that comparative evaluation of BCP is typically done using subjective judgments.

This research uses a case study approach focusing on a single organization and a single business continuity application to propose the use of computer simulation as a tool for managers to identify and evaluate different BCP prior to committing resources. In the context of an insurance firm, …


Use And Analysis Of Expected Similarity Of Semantic Web Ontological Annotations, Joe Lynn Look Jan 2008

Use And Analysis Of Expected Similarity Of Semantic Web Ontological Annotations, Joe Lynn Look

CCAC Theses and Dissertations

This dissertation studied various means of calculating similarity in the annotations of web pages compared to the similarity of the document text. A software tool, named Semantic Web Analysis of Similarity (SW AS), was developed and utilized to perform the analysis of similarity in annotated documents published from the first three years of the International Semantic Web Conference. Rules concerning the ontological concepts of the documents were specified and these rules as well as other parameters were varied to determine the effect on overall similarity measures. Traditional measures of similarity as well as enhanced measures of similarity proposed for this …


Reducing Cognitive Load Using Hypervariate Display, William Garrabrants Jan 2008

Reducing Cognitive Load Using Hypervariate Display, William Garrabrants

CCAC Theses and Dissertations

This research examined the application of hypervariate display principles to human-computer interfaces with the intent of reducing the cognitive load placed on the operator during high-intensity activity. This research extended the existing body of knowledge relevant to reducing the cognitive load using human-computer interfaces. Existing research has explored the application of techniques that, when used in isolation, contribute to a computer operator's understanding of the data or efficiency in execution of tasks. This research studied the collaborative use of proven display techniques to improve a computer operator's ability to understand large amounts of data more rapidly and react to that …


A Novel Theoretical Procedure To Determine Absorption And Gain Coefficients In A Symmetric Single Step-Index Quantum Well Laser, Mustafa Temi̇z, Özgür Önder Karakilinç, Mehmet Ünal Jan 2008

A Novel Theoretical Procedure To Determine Absorption And Gain Coefficients In A Symmetric Single Step-Index Quantum Well Laser, Mustafa Temi̇z, Özgür Önder Karakilinç, Mehmet Ünal

Turkish Journal of Electrical Engineering and Computer Sciences

If the indices n_{II}, n_{I,III} of the regions, the thickness 2a of the active region (AR) and the wavelength \lambda for a single symmetric step-index quantum well laser (SSSIQWL) are given, the normalized propagation constant (NPC) \alpha is obtained. In this novel method, absorption and gain coefficients for the SSSIQWL have been obtained in terms of the NPCs \alpha in the even and odd fields, directly.


Online Tuning Of Set-Point Regulator With A Blending Mechanism Using Pi Controller, Engi̇n Yeşi̇l, Müjde Güzelkaya, İbrahi̇m Eksi̇n, Ö. Aydin Teki̇n Jan 2008

Online Tuning Of Set-Point Regulator With A Blending Mechanism Using Pi Controller, Engi̇n Yeşi̇l, Müjde Güzelkaya, İbrahi̇m Eksi̇n, Ö. Aydin Teki̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new control structure that exploits the advantages of one degree of freedom (1-DOF) and two degree of freedom (2-DOF) control structures with an online tuned set-point regulator with blending mechanism (SPR-BM) is proposed. In this structure, the filtered output of the reference and the pure reference signals are blended so that the overall performance of the system is ameliorated with respect to load disturbance rejection and set-point following. Internal Model Control (IMC) based PI controller is used as the primary controller and the blending dynamics are determined with the aim of producing a system output that …


A New Approach Using Temporal Radial Basis Function In Chronological Series, Mustapha Guezouri Jan 2008

A New Approach Using Temporal Radial Basis Function In Chronological Series, Mustapha Guezouri

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present an extended form of Radial Basis Function network called Temporal-RBF (T-RBF) network. This extended network can be used in decision rules and classification in Spatio-Temporal domain applications, like speech recognition, economic fluctuations, seismic measurements and robotics applications. We found that such a network complies with relative ease to constraints such as capacity of universal approximation, sensibility of node, local generalisation in receptive field, etc. For an optimal solution based on a probabilistic approach with a minimum of complexity, we propose two TRBF models (1 and 2). Application to the problem of Mackey-Glass time series has …


Recent Advances In Perfectly Matched Layers In Finite Element Applications, Özlem Özgün, Mustafa Kuzuoğlu Jan 2008

Recent Advances In Perfectly Matched Layers In Finite Element Applications, Özlem Özgün, Mustafa Kuzuoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

We present a comparative evaluation of two novel and practical perfectly matched layer (PML) implementations to the problem of mesh truncation in the finite element method (FEM): locally-conformal PML, and multi-center PML techniques. The most distinguished feature of these methods is the simplicity and flexibility to design conformal PMLs over challenging geometries, especially those with curvature discontinuities, in a straightforward way without using artificial absorbers. These methods are based on specially- and locally-defined complex coordinate transformations inside the PML region. They can easily be implemented in a conventional FEM by just replacing the nodal coordinates inside the PML region by …


The Characteristic Basis Function Method (Cbfm): A Numerically Efficient Strategy For Solving Large Electromagnetic Scattering Problems, Eugenio Lucente, Gianluigi Tiberi, Agostino Monorchio, Giuliano Manara, Raj Mittra Jan 2008

The Characteristic Basis Function Method (Cbfm): A Numerically Efficient Strategy For Solving Large Electromagnetic Scattering Problems, Eugenio Lucente, Gianluigi Tiberi, Agostino Monorchio, Giuliano Manara, Raj Mittra

Turkish Journal of Electrical Engineering and Computer Sciences

The objective of this paper is to describe a numerically efficient strategy for solving large electromagnetic scattering problems. This novel approach, termed as the Characteristic Basis Function Method (CBFM), is based on utilizing Characteristic Basic Functions (CBFs)-special functions defined on macro domains (blocks)-that include a relatively large number of conventional sub-domains discretized by using triangular or rectangular patches. The CBFs can be derived either analytically (from PO solutions), or by applying the conventional MoM. Use of these basis functions leads to a significant reduction in the number of unknowns, and results in a substantial size reduction of the MoM matrix. …


Assessing Quality Indicators In Asynchronous Undergraduate Distance Education Courses, Donna J. Myers Jan 2008

Assessing Quality Indicators In Asynchronous Undergraduate Distance Education Courses, Donna J. Myers

CCAC Theses and Dissertations

The purpose of this study was to determine quality indicators within asynchronous distance education undergraduate courses at an accredited institution. The definition of quality is in and of itself obscure. Therefore, the identification of indicators or characteristics of quality in courses was a primary focus. The identification of such characteristics was based on input from the primary stakeholders in distance education, namely, the students, the administrators, and the instructors. Collecting data from each stakeholder group allowed for a comparison of those characteristics of quality deemed most important by each group. Initially an expert panel meeting was conducted to help categorize …


Smart Classroom Technology: Instructional Effectiveness And Faculty And Student Satisfaction, Jon Preston Mckamey Jan 2008

Smart Classroom Technology: Instructional Effectiveness And Faculty And Student Satisfaction, Jon Preston Mckamey

CCAC Theses and Dissertations

Numerous designs, practices, stakeholders, and technology options make it difficult for higher education institutions to find direction and established standards for classroom construction and remodeling projects. Different models of technology-enhanced classrooms are being adopted as various managers, integrators, and architects develop new classroom spaces. A planning process, standardized classroom model, and effective support structure will be valuable elements in meeting the needs of faculty and students.

The goal was to establish a best practices classroom model to meet the needs of community college faculty, students, and technology support personnel. Information collected from community colleges was used to determine the state …


Web 2.0 Tools Improve Teaching And Collaboration In High School English Language Classes, Mahmud Shihab Jan 2008

Web 2.0 Tools Improve Teaching And Collaboration In High School English Language Classes, Mahmud Shihab

CCAC Theses and Dissertations

Web 2.0 tools, namely blogs, wikis, podcasts, and RSS were introduced to change teaching practices of in-service high school teachers to improve the collaboration of today's students in the English language classroom. Two high school teachers of English language and their classes participated. The teachers were interviewed about their current teaching practices and provided with training to develop teaching units that use Web 2.0 to engage students as active collaborators in their learning. They integrated blogs, podcasts, wikis, and RSS into their teaching. Additional interviews were conducted during and after the implementation stage. Implementation strategies, changes in teaching practices, challenges …


Improving Knowledge Management Programs Using Marginal Utility In A Metric Space Generated By Conceptual Graphs, Jeffrey A. Schiffel Jan 2008

Improving Knowledge Management Programs Using Marginal Utility In A Metric Space Generated By Conceptual Graphs, Jeffrey A. Schiffel

CCAC Theses and Dissertations

Knowledge management has emerged as a field of endeavor that blends a systems approach with methods drawn from organizational management and learning. In contrast, knowledge representation, a branch of artificial intelligence, is grounded in formal methods. Research in the separate behavioral and the structural disciplines – knowledge management and knowledge engineering - has not traditionally cross-pollinated. This has prevented the development of many practical practices useful in organizations. Organization managers - line and senior - lack guidance in where to direct improvement efforts targeted at specific groups of company knowledge workers. Demonstrated here is Knowledge Improvement Measurement Space (KIMS), a …


An Event Monitor And Response Framework Based On The Wsloga Architecture, Todd Christopher Brett Jan 2008

An Event Monitor And Response Framework Based On The Wsloga Architecture, Todd Christopher Brett

CCAC Theses and Dissertations

Web services provide organizations with a powerful infrastructure by which information and products may be distributed, but the task of supporting Web service systems can be difficult due to the complex nature of environment configuration and operation. Tools are needed to monitor and analyze such Enterprise environments so that appropriate engineering, quality control, or business activities can be pursued.

This investigation resulted in the development of a software development kit, the WSLogA Framework, which is inspired by the vision of Cruz et al. (2003, 2004). The WSLogA Framework provides distributed Enterprise systems with a platform for comprehensive information capture and …


Modeling Timed Component-Based Real-Time Systems, Huang-Ming Huang, Christopher Gill Jan 2008

Modeling Timed Component-Based Real-Time Systems, Huang-Ming Huang, Christopher Gill

All Computer Science and Engineering Research

Component based middleware helps to facilitate software reuse by separating application-specific concerns into modular components that are shielded from the concerns of other components and from the common concerns addressed by underlying middleware services. In real-time systems, concerns such as invocation rates, execution latencies, deadlines, and concurrency semantics cross-cut multiple component and middleware abstractions. Thus, the verification of these systems must consider features of the application components (e.g., their execution latencies and relative invocation rates) and of the supporting middleware (e.g., concurrency and scheduling) together. However, existing approaches only address a sub-set of the features that must be modeled in …


Scheduling For Reliable Execution In Autonomic Systems, Terry Tidwell, Robert Glaubius, Christopher Gill, William D. Smart Jan 2008

Scheduling For Reliable Execution In Autonomic Systems, Terry Tidwell, Robert Glaubius, Christopher Gill, William D. Smart

All Computer Science and Engineering Research

Scheduling the execution of multiple concurrent tasks on shared resources such as CPUs and network links is essential to ensuring the reliable operation of many autonomic systems. Well known techniques such as rate-monotonic scheduling can offer rigorous timing and preemption guarantees, but only under assumptions (i.e., a fixed set of tasks with well-known execution times and invocation rates) that do not hold in many autonomic systems. New hierarchical scheduling techniques are better suited to enforce the more flexible execution constraints and enforcement mechanisms that are required for autonomic systems, but a rigorous foundation for verifying and enforcing concurrency and timing …


Partial Program Admission By Path Enumeration, Michael Wilson, Ron Cytron, Jon Turner Jan 2008

Partial Program Admission By Path Enumeration, Michael Wilson, Ron Cytron, Jon Turner

All Computer Science and Engineering Research

Real-time systems on non-preemptive platforms require a means of bounding the execution time of programs for admission purposes. Worst-Case Execution Time (WCET) is most commonly used to bound program execution time. While bounding a program's WCET statically is possible, computing its true WCET is difficult without significant semantic knowledge. We present an algorithm for partial program admission, suited for non-preemptive platforms, using dynamic programming to perform explicit enumeration of program paths. Paths - possible or not - are bounded by the available execution time and admitted on a path-by-path basis without requiring semantic knowledge of the program beyond its Control …


Practical Schedulability Analysis For Generalized Sporadic Tasks In Distributed Real-Time Systems, Yuanfang Zhang, Donald K. Krecker, Christopher Gill, Chenyang Lu, Guatam H. Thaker Jan 2008

Practical Schedulability Analysis For Generalized Sporadic Tasks In Distributed Real-Time Systems, Yuanfang Zhang, Donald K. Krecker, Christopher Gill, Chenyang Lu, Guatam H. Thaker

All Computer Science and Engineering Research

Existing off-line schedulability analysis for real-time systems can only handle periodic or sporadic tasks with known minimum inter-arrival times. Modeling sporadic tasks with fixed minimum inter-arrival times is a poor approximation for systems in which tasks arrive in bursts, but have longer intervals between the bursts. In such cases, schedulability analysis based on the existing sporadic task model is pessimistic and seriously overestimates the task's time demand. In this paper, we propose a generalized sporadic task model that characterizes arrival times more precisely than the traditional sporadic task model, and we develop a corresponding schedulability analysis that computes tighter bounds …


Local Neighborhoods For Shape Classification And Normal Estimation, Cindy Grimm, William Smart Jan 2008

Local Neighborhoods For Shape Classification And Normal Estimation, Cindy Grimm, William Smart

All Computer Science and Engineering Research

We introduce the concept of local neighborhoods, a generalization of the one-ring on a mesh to unlabeled 3D data points arising from sampling a 2D surface embedded in 3D. The local neighborhood supports both local shape classification and robust normal estimation. In particular, local neighborhoods out-perform traditional approaches in unevenly sampled, curved regions. We show that the local neighborhood can be used in place of a full mesh structure for applications such as smoothing, moving least-squares reconstruction, and parameterization. Longer version of paper submitted to CAGD


Financial Monte Carlo Simulation On Architecturally Diverse Systems, Naveen Singla, Michael Hall, Berkley Shands, Roger D. Chamberlain Jan 2008

Financial Monte Carlo Simulation On Architecturally Diverse Systems, Naveen Singla, Michael Hall, Berkley Shands, Roger D. Chamberlain

All Computer Science and Engineering Research

Computational finance relies heavily on the use of Monte Carlo simulation techniques. However, Monte Carlo simulation is computationally very demanding. We demonstrate the use of architecturally diverse systems to accelerate the performance of these simulations, exploiting both graphics processing units and field-programmable gate arrays. Performance results include a speedup of 74× relative to an 8 core multiprocessor system (180× relative to a single processor core).