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2004

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Articles 91 - 120 of 253

Full-Text Articles in Computer Engineering

Volume Holographic Recording And Readout For 90-Deg Geometry, Partha P. Banerjee, Monish Ranjan Chatterjee, Nickolai Kukhtarev, Tatiana Kukhtareva Sep 2004

Volume Holographic Recording And Readout For 90-Deg Geometry, Partha P. Banerjee, Monish Ranjan Chatterjee, Nickolai Kukhtarev, Tatiana Kukhtareva

Electrical and Computer Engineering Faculty Publications

When a prerecorded cross-beam hologram is reconstructed (so-called edge-lit readout) with a uniform plane wave and a point source, the resulting exact solutions reveal Bessel-function-type diffracted beam profiles, which are fundamentally modified under weak propagational diffraction. The case of a profiled beam readout with propagational diffraction may be analyzed using a transfer function approach based on 2-D Laplace transforms. In a second series of investigations, dynamic readout from a cross-beam volume hologram recorded with two orthogonal uniform plane waves is considered for various dependences of the refractive index modulation with intensity. Typically, refractive index profiles that are proportional to the …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 1, September 2004, College Of Engineering And Computer Science, Wright State University Sep 2004

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 1, September 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


Run-Time Modification Of The Class Hierarchy In A Live Java Development Environment, Joel R. Brandt, Kenneth J. Goldman Sep 2004

Run-Time Modification Of The Class Hierarchy In A Live Java Development Environment, Joel R. Brandt, Kenneth J. Goldman

All Computer Science and Engineering Research

Class hierarchy design is central to object-oriented software development. However, it is sometimes difficult for developers to anticipate all the implications of a design until implementation is underway. To support experimentation with different designs, we extend prior work on live development environments to allow run-time modification of the class hierarchy. The result is a more fluid object-oriented development process, in which immediate feedback from the executing program can be used to guide hierarchy design. This paper presents a framework and developer support for run-time modification of class inheritance relations in JPie, a live visual programming environment for Java. Most notably, …


Device Discovery In Frequency Hopping Wireless Ad Hoc Networks, Brian S. Peterson Sep 2004

Device Discovery In Frequency Hopping Wireless Ad Hoc Networks, Brian S. Peterson

Theses and Dissertations

This research develops a method for efficient discovery of wireless devices for a frequency hopping spread spectrum, synchronous, ad hoc network comprised of clustered sub-networks. The Bluetooth wireless protocol serves as the reference protocol. The development of a discovery, or outreach, method for scatternets requires the characterization of performance metrics of Bluetooth piconets, many of which are unavailable in literature. Precise analytical models characterizing the interference caused to Bluetooth network traffic by inquiring devices, the probability mass function of packet error rates between arbitrary pairs of Bluetooth networks, and Bluetooth discovery time distribution are developed. Based on the characterized performance …


Every Polynomial-Time 1-Degree Collapses If And Only If P=Pspace, Stephen A. Fenner, Stuart A. Kurtz, James S. Royer Sep 2004

Every Polynomial-Time 1-Degree Collapses If And Only If P=Pspace, Stephen A. Fenner, Stuart A. Kurtz, James S. Royer

Faculty Publications

No abstract provided.


Volume Holographic Optical Elements, Ching-Cherng Sun, Partha P. Banerjee Sep 2004

Volume Holographic Optical Elements, Ching-Cherng Sun, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

The final two papers are concerned with the analysis of novel holograms. Banerjee et al. investigate holographic recording and reconstruction for edge-lit holograms recorded in a 90-degree geometry. Various cases of recording and readout that incorporate propagational diffraction have been modeled. It is shown that the 90-degree geometry can result in beam shaping, as evidenced through preliminary experimental results with photorefractive lithium niobate. Nguyen et al. propose a new approach for designing computer-generated holograms. An artificial neural network is used to initiate the genetic algorithm so that the high computation cost of genetic algorithms for synthesizing holograms is significantly reduced …


Power-Stepped Protocol: Enhancing Spatial Utilization In A Clustered Mobile Ad Hoc Network, Chansu Yu, Kang G. Shin, Ben Lee Sep 2004

Power-Stepped Protocol: Enhancing Spatial Utilization In A Clustered Mobile Ad Hoc Network, Chansu Yu, Kang G. Shin, Ben Lee

Electrical and Computer Engineering Faculty Publications

While most previous studies on mobile ad hoc networks (MANETs) rely on the assumption that nodes are randomly distributed in the network coverage area, this assumption is unlikely to hold, as nodes tend to be cluttered around hot spots like the site of an accident or disaster. We refer to this as a clustered layout. Intuitively, a MANET with the clustered layout may suffer from serious performance degradation due to the excessive collisions in congested hot spots and space underutilization of sparse areas. In this paper, we propose a power-controlled network protocol, called the power-stepped protocol (PSP), that maximizes the …


Optimizing Proportionally Fair Prices, Laura Wynter Sep 2004

Optimizing Proportionally Fair Prices, Laura Wynter

Research Collection School Of Computing and Information Systems

We demonstrate the non-uniqueness of proportional fairness prices, and show that the model of Kelly et al. [9] falls into the category of models that can be generalized to allow optimization of the link prices, with a view toward profit maximization. However, through this framework, we also show that the total revenue that can be obtained through proportional fairness pricing on a network is unique.


Ultra Wideband Communication Link, Preeti Singh Aug 2004

Ultra Wideband Communication Link, Preeti Singh

Theses

Ultra-wideband communication (UWB) has been a topic of extensive research in recent years especially for its short-range communication and indoor applications. The preliminary objective of the project was to develop a description and understanding of the basic components of the communication link at microwave frequencies in order to achieve the primary objective of establishing a communication setup at a bandwidth of 2.5 GHz for testing Ultra Wideband (UWB) antennas. This was achieved with the aid of commercially available optical system which was modified for the purpose. Beginning with the generation of baseband narrow pulses with energy spanning over a broad …


Scheduling Algorithms For Cioq Switches, Prashanth Pappu, Jonathan S. Turner Aug 2004

Scheduling Algorithms For Cioq Switches, Prashanth Pappu, Jonathan S. Turner

All Computer Science and Engineering Research

Most scalable switches are required to buffer packets at both their inputs and outputs to overcome the slow memory speeds of packet queues. This thesis deals with the design of scheduling algorithms for such Combined Input and Output Queued (CIOQ) switches. For crossbar based CIOQ switches, we demonstrate the underperformance of commercially used scheduling algorithms under overload traffic conditions using targeted stress tests and present ideas to develop robust, stress resistant versions of these algorithms that are still simple enough to be implemented in high speed switches. To regulate the flow of traffic in buffered, multi-stage switches, we introduce a …


Wavelenght-Dispersive X-Ray Flourescence Accuration, H. Widyatmoko Aug 2004

Wavelenght-Dispersive X-Ray Flourescence Accuration, H. Widyatmoko

Makara Journal of Technology

Wavelenght–Dispersive X-Ray Flourescence Accuration. X-Fuorescence spectrometry is a method, which is increasingly applied in the geochemical analysis. X-Fuorescence spectrometry is classified under two categories – WDXRF (wavelenght – dispersive X-ray fluorescence spectrometer) and EDXRF (energy-dispersive X – ray fluorescence spectrometer). WDXRF can be configured as a sequential spectrometer , a simultaneous spectrometer or a hibrid instrument, which combines the advantages of the simultaneous and sequential spectrometers into one instrument. Each instrument is different in some characteristics, and each has applications for which it is specifically suited. In this investigation sequential spectrometer PW 1450 was used to analyze the major, minor …


Secondary Flow Experimental Study For Axial Compressor Cascade Strong Stagger With And Without Tip- Clearance: Static Pressure Distribution On Blade Surface, Syamsuri Syamsuri Aug 2004

Secondary Flow Experimental Study For Axial Compressor Cascade Strong Stagger With And Without Tip- Clearance: Static Pressure Distribution On Blade Surface, Syamsuri Syamsuri

Makara Journal of Technology

Secondary Flow Experimental Study for Axial Compressor Cascade Strong Stagger With and Without Tip- Clearance: Static Pressure Distribution on Blade Surface. The performance of blade cascade is influenced by the growth and boundary layer’s separation along blade surface and endwall (casing and hub). The secondary flow which happens near hub and casing compressors is three dimentional flow separation phenomenon comes from interaction blade boundary layer with casing and hub boundary layers in the compressor. The secondary flow causes secondary losses, blockage effect, and turning angle (deflection) distribution along blade span. The result of the research shows that the increase of …


Effect Of Photoperiodicity On Co2 Fixation By Chlorella Vulgaris Buitenzorg In Bubble Column Photobioreactor For Food Supplement Production, Anondho Wijanarko, Dianursanti Dianursanti, Arief Budi Witarto, Roekmijati Widaningroem Soemantojo Aug 2004

Effect Of Photoperiodicity On Co2 Fixation By Chlorella Vulgaris Buitenzorg In Bubble Column Photobioreactor For Food Supplement Production, Anondho Wijanarko, Dianursanti Dianursanti, Arief Budi Witarto, Roekmijati Widaningroem Soemantojo

Makara Journal of Technology

To reduce the level of CO2 content in air, effort on converting CO2 to useful products is required. One of the alternatives includes CO2 fixation to produce biomass using Chlorella vulgaris Buitenzorg. Chlorella vulgaris Buitenzorg is applied for production of food supplement. Chlorella vulgaris Buitenzorg is also easy to handle due to its superior adaptation. Currently, Chlorella vulgaris Buitenzorg has been analyzed by some experts for its cellular composition, its ability to produce high quality biomass and the content of essential nutrition. A series of experiments was conducted by culturing Chlorella vulgaris Buitenzorg using Beneck medium in bubbling column photobioreactor. …


Synthesize Of Emulsion Polymer Latex For Sub-Grade Cbr Improvement In The Road Construction, Keba Moto, V. Julian, Syamsudin Syamsudin, T. A. Wiradi, S. R. Wijaya Aug 2004

Synthesize Of Emulsion Polymer Latex For Sub-Grade Cbr Improvement In The Road Construction, Keba Moto, V. Julian, Syamsudin Syamsudin, T. A. Wiradi, S. R. Wijaya

Makara Journal of Technology

Synthesize of emulsion polymer latex for sub-grade CBR improvement in the road construction. Latex polymer for California Bearing Ratio (CBR) enhancement in sub-grade soil of road building has been prepared by emulsion polymerizations technique. The prepared polymer then characterize by Fourier Transform Infrared (FTIR). For application purpose, CBR test was done to the compacted polymer added-soil. The CBR test is done also for both soaked and unsoaked samples. It is found that our latex polymer is better then other imported latex polymer. For the latex polymer, which is design to have Temperatur glass (Tg) around 9.8-19.6o, indicating the formation of …


Generating Properties For Runtime Monitoring From Software Specification Patterns, Oscar Mondragon, Ann Q. Gates, Oleg Sokolsky Aug 2004

Generating Properties For Runtime Monitoring From Software Specification Patterns, Oscar Mondragon, Ann Q. Gates, Oleg Sokolsky

Departmental Technical Reports (CS)

The paper presents an approach to support run-time verification of software systems that combines two existing tools, Prospec and Java-MaC, into a single framework. Prospec can be used to clarify natural language specifications for sequential, concurrent, and nondeterministic behavior. In addition, the tool assists the user in reading, writing, and understanding formal specifications through the use of property patterns and visual abstractions. Currently, Prospec automatically generates a specification written in Future Interval Logic (FIL). The goal is to automate the generation of MEDL formulas that can be used by the Java-MaC tool to check run-time compliance of system execution to …


Non-Lexical Conversational Sounds In American English, Nigel Ward Aug 2004

Non-Lexical Conversational Sounds In American English, Nigel Ward

Departmental Technical Reports (CS)

This article analyzes the non-lexical conversational sounds (conversational grunts) of English, including such items as uh-huh, un-hn, um, mm, and oh, based primarily on examination of a few hundred occurrences in a corpus of conversations. The data includes extensive phonetic variation, suggesting that these items are best explained, not as fixed words, but as dynamic creations. In particular, the vast majority of these items can be generated by a simple model consisting of 10 component sounds and 2 combining rules. Moreover, each of these component sounds seems to bear some meaning or function which is fairly constant across grunts and …


Discovering Transcriptional Regulatory Rules From Gene Expression And Tf-Dna Binding Data By Decision Tree Learning, Jianhua Ruan, Weixiong Zhang Jul 2004

Discovering Transcriptional Regulatory Rules From Gene Expression And Tf-Dna Binding Data By Decision Tree Learning, Jianhua Ruan, Weixiong Zhang

All Computer Science and Engineering Research

Background: One of the most promising but challenging task in the post-genomic era is to reconstruct the transcriptional regulatory networks. The goal is to reveal, for each gene that responds to a certain biological event, which transcription factors affect its transcription, and how several transcription factors coordinate to accomplish specific regulations. Results: Here we propose a supervised machine learning approach to address these questions. We build decision trees to associate the expression level of a gene with the transcription factor binding data of its promoter. From the decision trees, we extract regulatory rules that specify how the binding of a …


Field-Programmable Analog Arrays: A Floating-Gate Approach, Tyson S. Hall Jul 2004

Field-Programmable Analog Arrays: A Floating-Gate Approach, Tyson S. Hall

Faculty Works

Field-programmable analog arrays (FPAAs) provide a method for rapidly pro- totyping analog systems. Currently available commercial and academic FPAAs are typically based on operational amplifiers (or other similar analog primitives) with only a few computational elements per chip. While their specific architectures vary, their small sizes and often restrictive interconnect designs leave current FPAAs limited in functionality, flexibility, and usefulness. Recent advances in the area of floating-gate transistors have led to an analog technology that is very small, accurately programmable, and extremely low in power consumption. By leveraging the advantages of floating-gate devices, a large-scale FPAA is designed that dramatically …


Visual Impact Of The Illuminations Of Lcd Monitor Under Different Ambient Lightings, Yuichi Yuasa Jul 2004

Visual Impact Of The Illuminations Of Lcd Monitor Under Different Ambient Lightings, Yuichi Yuasa

Graduate Research Papers

As criticisms about the eyestrain of computer monitor are increased, the interaction between human and VDTs has been examined. The studies of visual performance of LCD monitor are emphasized with numerous advantages. This study investigated the differences of visual comfort among three levels of illumination of an LCD monitor and ambient lighting. A statis ti cal experience was conducted concerning the procedure ofISO's recommendations with sample participants in the selected area. After the analysis of the data using ANOVA, the result showed the statistically significant difference and significant interaction between two variables. The combination between both medium ambient lighting and …


Beyond Convex? Global Optimization Is Feasible Only For Convex Objective Functions: A Theorem, R. Baker Kearfott, Vladik Kreinovich Jul 2004

Beyond Convex? Global Optimization Is Feasible Only For Convex Objective Functions: A Theorem, R. Baker Kearfott, Vladik Kreinovich

Departmental Technical Reports (CS)

It is known that there are feasible algorithms for minimizing convex functions, and that for general functions, global minimization is a difficult (NP-hard) problem. It is reasonable to ask whether there exists a class of functions that is larger than the class of all convex functions for which we can still solve the corresponding minimization problems feasibly. In this paper, we prove, in essence, that no such more general class exists. In other words, we prove that global optimization is always feasible only for convex objective functions.


Optimal Finite Characterization Of Linear Problems With Inexact Data, Vladik Kreinovich Jul 2004

Optimal Finite Characterization Of Linear Problems With Inexact Data, Vladik Kreinovich

Departmental Technical Reports (CS)

For many linear problems, in order to check whether a certain property is true for all matrices A from an interval matrix [A], it is sufficient to check this property for finitely many "vertex" matrices. J. Rohn has discovered that we do not need to use all 2^(n^2) vertex matrices, it is sufficient to only check these properties for 2^(2n-1)<<2^(n^2) vertex matrices of a special type A_{yz}. In this paper, we show that a further reduction is impossible: without checking all 2^(2n-1) matrices A_{yz}, we cannot guarantee that the desired property holds for all A from [A]. Thus, these special vertex matrices provide an optimal finite characterization of linear problems with inexact data.


Outlier Detection Under Interval Uncertainty: Algorithmic Solvability And Computational Complexity, Vladik Kreinovich, Luc Longpre, Praveen Patangay, Scott Ferson, Lev Ginzburg Jul 2004

Outlier Detection Under Interval Uncertainty: Algorithmic Solvability And Computational Complexity, Vladik Kreinovich, Luc Longpre, Praveen Patangay, Scott Ferson, Lev Ginzburg

Departmental Technical Reports (CS)

In many application areas, it is important to detect outliers. Traditional engineering approach to outlier detection is that we start with some "normal" values x1,...,xn, compute the sample average E, the sample standard variation sigma, and then mark a value x as an outlier if x is outside the k0-sigma interval [E-k0*sigma,E+k0*sigma] (for some pre-selected parameter k0). In real life, we often have only interval ranges [xi] for the normal values x1,...,xn. In this case, we only have intervals of possible values for the bounds E-k0*sigma and E+k0*sigma. We can therefore identify outliers as values that are outside all k0-sigma …


Towards Combining Probabilistic And Interval Uncertainty In Engineering Calculations, Scott A. Starks, Vladik Kreinovich, Luc Longpre, Martine Ceberio, Gang Xiang, Roberto Araiza, J. Beck, R. Kandathi, A. Nayak, R. Torres Jul 2004

Towards Combining Probabilistic And Interval Uncertainty In Engineering Calculations, Scott A. Starks, Vladik Kreinovich, Luc Longpre, Martine Ceberio, Gang Xiang, Roberto Araiza, J. Beck, R. Kandathi, A. Nayak, R. Torres

Departmental Technical Reports (CS)

In many engineering applications, we have to combine probabilistic and interval errors. For example, in environmental analysis, we observe a pollution level x(t) in a lake at different moments of time t, and we would like to estimate standard statistical characteristics such as mean, variance, autocorrelation, correlation with other measurements. In environmental measurements, we often only know the values with interval uncertainty. We must therefore modify the existing statistical algorithms to process such interval data. Such modification are described in this paper.


Computing 2-Step Predictions For Interval-Valued Finite Stationary Markov Chains, Marcilia Andrade Campos, Gracaliz Pereira Dimuro, Antonio Carlos Da Rocha Costa, Vladik Kreinovich Jul 2004

Computing 2-Step Predictions For Interval-Valued Finite Stationary Markov Chains, Marcilia Andrade Campos, Gracaliz Pereira Dimuro, Antonio Carlos Da Rocha Costa, Vladik Kreinovich

Departmental Technical Reports (CS)

Markov chains are a useful tool for solving practical problems. In many real-life situations, we do not know the exact values of initial and transition probabilities; instead, we only know the intervals of possible values of these probabilities. Such interval-valued Markov chains were considered and analyzed by I. O. Kozine and L. V. Utkin in their Reliable Computing paper. In their paper, they propose an efficient algorithm for computing interval-valued probabilities of the future states. For the general case of non-stationary Markov chains, their algorithm leads to the exact intervals for the probabilities of future states.

In the important case …


Cs 340: Programming Language Workshop In Java, Ronald F. Taylor Jul 2004

Cs 340: Programming Language Workshop In Java, Ronald F. Taylor

Computer Science & Engineering Syllabi

This course is designed as a self-study in Java. You are expected to work independently to learn the Java language and solve a set of programming problems assigned to you using latest Java SDK available at http://java.sun.com or other software as approved by the instructor. There are no exams. We officially meet only once in a quarter. However, I will be available in the posted office hours for clarifications and general discussion of the programming assignments. Do not expect support in debugging badly documented code.


Cs 214: Object Oriented Programming, Roddy Keish Jul 2004

Cs 214: Object Oriented Programming, Roddy Keish

Computer Science & Engineering Syllabi

No abstract provided.


Teabag: A Debugger For Curry, Stephen Lee Johnson Jul 2004

Teabag: A Debugger For Curry, Stephen Lee Johnson

Dissertations and Theses

This thesis describes TeaBag, which is a debugger for functional logic computations. TeaBag is an accessory of a virtual machine currently under development. A distinctive feature of this machine is its operational completeness of computations, which places novel demands on a debugger. This thesis describes the features of TeaBag, in particular the handling of non-determinism, the ability to control nondeterministic steps, to remove context information, to toggle eager evaluation, and to set breakpoints on both functions and terms. This thesis also describes TeaBag's architecture and its interaction with the associated virtual machine. Finally, some debugging sessions of defective programs are …


Functional Model Of The Army's Initial Capabilities Training Plan (Ictp) Generation Process (Transitioning To A Knowledge-Base Enterprise), Bryon Keith Hartzog Jul 2004

Functional Model Of The Army's Initial Capabilities Training Plan (Ictp) Generation Process (Transitioning To A Knowledge-Base Enterprise), Bryon Keith Hartzog

Computational Modeling & Simulation Engineering Theses & Dissertations

Background: The Army's transformation of its requirements and acquisition process to the Joint Capabilities Integration Development System (JCIDS), supporting the paradigm shift from a threat-based to capabilities-based methodology, signifies that the training/ training support business processes must also change. The new Capabilities Integration Development System - Army (CIDS-A) will prevent the development of service-only oriented materiel solutions that do not interoperate. Additionally, the CIDS-A will force early analysis across the Doctrine, Organization, Training, Leader, Material, Personnel, and Facilities (DOTLMPF) focus areas. This early DOTLMPF analysis ensures materiel solutions incorporate dynamic and flexible training/ training support. To efficiently manage the training …


Interactive Land Use Vrml Application Using Servlet Assist, Suresh Chitithoti Jul 2004

Interactive Land Use Vrml Application Using Servlet Assist, Suresh Chitithoti

Electrical & Computer Engineering Theses & Dissertations

The integration of VRML and Servlet technologies has the potential to revolutionize web-based simulation visualization. The Interactive Land Use VRML Application (ILUVA) uses Java Servlets enabling one to perform urban planning by taking a virtual land area and add buildings, roadways, landscaping, and other features. The Virtual Reality Modeling Language (VRML) is a web-based technology for specifying and delivering interactive three-dimensional visualizations over a browser. The Java Servlet technology offers several powerful capabilities such as user authentication, session management, database connectivity for maintaining several possibly simultaneous user sessions, and dynamically generated VRML. Save and restore capabilities for any applications are …


Qos Provisioning For Multi-Class Traffic In Wireless Networks, Mona El-Kadi Rizvi Jul 2004

Qos Provisioning For Multi-Class Traffic In Wireless Networks, Mona El-Kadi Rizvi

Computer Science Theses & Dissertations

Physical constraints, bandwidth constraints and host mobility all contribute to the difficulty of providing Quality of Service (QoS) guarantees in wireless networks. There is a growing demand for wireless networks to support all the services that are available on wired networks. These diverse services, such as email, instant messaging, web browsing, video conferencing, telephony and paging all place different demands on the network, making QoS provisioning for wireless networks that carry multiple classes of traffic a complex problem. We have developed a set of admission control and resource reservation schemes for QoS provisioning in multi-class wireless networks.

We present three …