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2006

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Articles 2881 - 2910 of 3391

Full-Text Articles in Engineering

Effect Of Bulk Flow Modulations On A Normal Jet In Crossflow At A Mean Blowing Ratio Of 0.25, Jeremiah Oertling Jan 2006

Effect Of Bulk Flow Modulations On A Normal Jet In Crossflow At A Mean Blowing Ratio Of 0.25, Jeremiah Oertling

LSU Master's Theses

An experimental wind tunnel has been designed, built, outfitted with automated hot wire anemometry and laser sheet imagery systems methods of instrumentation and tested with the purpose of performing scientific research on the control and stabilization of a jet issuing 90 degrees into a crossflow. After the design and system characterizations were performed, the system was employed as a experimental platform to conduct an investigation of bulk flow modulation of a jet in crossflow. The Mean Blowing ratio investigated was set at 0.25, and the effect of duty cycle, peak to peak blowing ratio and frequency of excitation are investigated. …

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Em Algorithm For Multiple Wideband Source Localization, Kiran Kumar Mada Jan 2006

Em Algorithm For Multiple Wideband Source Localization, Kiran Kumar Mada

LSU Master's Theses

A computationally efficient algorithm using the expectation-maximization (EM) algorithm for multiple wideband source localization in the near field of a sensor array/area is addressed in this thesis. Our idea is to decompose the observed sensor data, which is a superimposition of multiple sources, into the individual components in the frequency domain and then estimate the corresponding location parameters associated with each component separately. Instead of the conventional alternating projection (AP) method, we propose to adopt the EM algorithm in this work; our new method involves two steps, namely Expectation (E-step) and Maximization (M-step). In the E-step, the individual incident source …

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Compiler Assisted Cache Prefetch Using Procedure Call Hierarchy, Sheela A. Doshi Jan 2006

Compiler Assisted Cache Prefetch Using Procedure Call Hierarchy, Sheela A. Doshi

LSU Master's Theses

Microprocessor performance has been increasing at an exponential rate while memory system performance improved at a linear rate. This widening difference in performances is increasingly rendering advances in computer architecture less useful as more instructions spend more time waiting for data to be fetched from the memory after a cache miss. Data prefetching is a technique that avoids some cache misses by bringing data into the cache before it is actually needed. Different approaches to data prefetching have been developed, however existing prefetch schemes do not eliminate all cache misses and even with smaller cache miss ratio, miss latency remains …

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Robust Fault-Tolerant Control For Aircraft Systems, Phalguna Kumar Rachinayani Jan 2006

Robust Fault-Tolerant Control For Aircraft Systems, Phalguna Kumar Rachinayani

LSU Master's Theses

The need to design controllers that guarantee both stability and performance upon the occurrence of faults has been an active area of research. To address this problem, in this thesis we present different methodologies to design robust controllers that guarantee both stability and robustness for actuator faults and uncertainties. In the first part of this thesis, we introduce the classical uncertainty formulation using Linear Fractional Transformation (LFT) and describe LFT's special cases-norm bounded and convex polytopic uncertainty descriptions. Practical methods to formulate these uncertainty structures are described. In the same spirit, formulation of faults and their modeling for robust control …

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Fundamental Characterization Of Louisiana Hma Mixtures For The 2002 Mechanistic-Empirical Design Guide, Sandeep Obulareddy Jan 2006

Fundamental Characterization Of Louisiana Hma Mixtures For The 2002 Mechanistic-Empirical Design Guide, Sandeep Obulareddy

LSU Master's Theses

The main objective of this research was to develop a catalog for dynamic modulus values inputs in the 2002 Empirical and Mechanistic Guide for Design of New and Rehabilitated Pavement Structures (2002 M-E Design Guide) and to examine the permanent deformation characteristics of Louisiana hot mix asphalt (HMA) mixtures based on four laboratory tests, namely dynamic modulus |E*|, flow number, flow time and hamburg wheel tracker test. In addition, the sensitivity of rut prediction from the 2002 M-E Design Guide, using the dynamic modulus |E*| test results was evaluated and the Witczak and Hirsch models were also evaluated, for the …

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Evaluation Of An Amperometric Biosensor For The Detection Of Escherichia Coli O157:H7, Danyelle Denise Small Jan 2006

Evaluation Of An Amperometric Biosensor For The Detection Of Escherichia Coli O157:H7, Danyelle Denise Small

LSU Master's Theses

Escherichia coli O157:H7 contamination is a major hazard in the water supply, causing outbreaks of disease. Conventional methods of E. coli O157:H7 detection usually takes 1-2 days and require hands-on preparation. There is a need to develop a rapid, inexpensive means of detecting the organism. The amperometric biosensor technology has achieved success in the area of metabolite detection. In this study, a bench scale amperometric biosensor was investigated to rapidly detect Escherichia coli O157:H7. The amperometric biosensor consisted of a power source, Clark electrode, autoranging picoammeter, and fabricated polyvinyl chloride (PVC) outer insert with nitrocellulose membrane and attached horseradish peroxidase …

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Acoustic Emission Monitoring And Quantitative Evaluation Of Damage In Reinforced Concrete Members And Bridges, Archana Nair Jan 2006

Acoustic Emission Monitoring And Quantitative Evaluation Of Damage In Reinforced Concrete Members And Bridges, Archana Nair

LSU Master's Theses

A considerable proportion of highway bridges in the US, are made of reinforced concrete. The vulnerability of these structures during their long service life is a cause of major concern for civil engineers. Since there is a need to detect and recuperate the condition of the bridge structures numerous innovative non-destructive testing (NDT) techniques have come into the forefront. Of the many available technologies, acoustic emission (AE) monitoring has been the most popular non-destructive technique used on highway bridges. Acoustic emission is a passive monitoring technique. Thus, it can be appropriately used for field bridge monitoring applications. Usually AE monitoring …

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Compositional Effects On Gas-Oil Interfacial Tension And Miscibility At Reservoir Conditions, Daryl Sean Sequeira Jan 2006

Compositional Effects On Gas-Oil Interfacial Tension And Miscibility At Reservoir Conditions, Daryl Sean Sequeira

LSU Master's Theses

Minimum miscibility pressure (MMP) is an important optimization parameter for an enhanced oil recovery process involving Carbon Dioxide or hydrocarbon gas injection. Therefore an accurate experimental measurement is required to determine the MMP. The MMP for a gas-oil system is directly related to the interfacial tension between the injected gas and the reservoir crude oil. When CO2 gas contacts the reservoir oil at reservoir temperature, the interfacial tension between the fluid-fluid phases reduces as the miscibility is approached and the interface between the fluid-fluid phases eventually disappears at miscibility i.e. the interfacial tension becomes zero. Hence, a pressure condition of …

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Mapping A Weak Hypercube On An Optical Slab Waveguide, Divya Rengan Jan 2006

Mapping A Weak Hypercube On An Optical Slab Waveguide, Divya Rengan

LSU Master's Theses

The communication fabric of a parallel processing system is represented as a directed graph. In a weak topology a processor uses at most one incoming edge or one outgoing edge for communication at any given point in time. Currently, the data rate that can be supported on electronic interconnects is reaching its limits. Optical interconnects have been identified as one of the most promising approaches to the growing demands for today's systems. The “medium bandwidth” of an optical waveguide is huge (order of petabits per second for a 1mm2 cross-section optical slab). The challenge lies in utilizing as much of …

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Characterization And Tribological Behavior Of Diamond-Like Carbon And Nitrogen-Doped Diamond-Like Carbon Thin Films, Krishna Chaitanya Kadiyala Jan 2006

Characterization And Tribological Behavior Of Diamond-Like Carbon And Nitrogen-Doped Diamond-Like Carbon Thin Films, Krishna Chaitanya Kadiyala

LSU Master's Theses

Diamond-like carbon (DLC) films have been extensively studied for more than two decades due to their highly attractive properties. These films exhibit unique mechanical, electrical and tribological behavior and thus, possess great potential for applications in tribology. However, the high level of internal stress developed and low thermal stability are the main drawbacks. Synthesis of nitrogen-doped DLC (N-DLC) offers the possibility of overcoming these drawbacks. In the present study, DLC and N-DLC films (with low N content) were deposited on Si substrates using a hybrid plasma-assisted CVD/PVD process. Film characterization in terms of microstructure, composition and chemical state of components …

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A Stochastic Mesoscopic Cell-Transmission Model For Operational Analysis Of Large-Scale Transportation Networks, Ciprian Danut Alecsandru Jan 2006

A Stochastic Mesoscopic Cell-Transmission Model For Operational Analysis Of Large-Scale Transportation Networks, Ciprian Danut Alecsandru

LSU Doctoral Dissertations

The cell transmission model (CTM), developed by Daganzo in 1994 was not fully exploited as an operations model for analysis of large-scale traffic networks. Because of its macroscopic / mesoscopic features, CTM offers calibration and computational advantages over microscopic models. This study presents a series of enhancements to the original form of CTM. These enhancements show potential to increase the model’s accuracy and realism of traffic flow representation. For example, topological enhancements and modifications to the flow advancing equation are introduced to allow variable cell lengths and non-discrete movements of vehicles between cells. In addition, implementation of lane-changing behavioral logics …

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Spectral Analysis Of Total Suspended Solids Mixtures For Solids Composition Determination, Curtis W. Sutherland Jan 2006

Spectral Analysis Of Total Suspended Solids Mixtures For Solids Composition Determination, Curtis W. Sutherland

LSU Doctoral Dissertations

Total Suspended Solids (TSS) analysis provides an initial and very basic measure for study and characterization of water quality. The present tedious procedures used for the identification of different solids constituents present in TSS and for the classification or insight into the origins of those solids are time-consuming and expensive. The research reported herein investigates the use of instrumental analysis using reflectance spectra of TSS as an attractive alternative to sufficiently characterize and identify TSS in a more rapid and economical method that could be used to study TSS transport and to identity TSS points of origin. For this investigative …

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Ultra-Violet Lithography Of Thick Photoresist For The Applications In Biomems And Micro Optics, Ren Yang Jan 2006

Ultra-Violet Lithography Of Thick Photoresist For The Applications In Biomems And Micro Optics, Ren Yang

LSU Doctoral Dissertations

UV lithography of thick photoresist is widely used in microelectromechanical systems (MEMS) and micro-optoelectromechanical systems (MOEMS). SU-8 is a typical negative tone thick photoresist for micro systems, and can be used for both structural material and pattern transfer. This dissertation presents an effort to comprehensively study these important subjects. The first part, and the most fundamental part of this dissertation concentrated on the numerical analysis and experimental study of the wavelength dependent absorbance of SU-8 and the diffraction effects on the sidewall profiles of the microstructures made using UV lithography of SU-8. This study has laid the foundation for all …

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A Study Of Phase Noise And Jitter In Submicron Cmos Phase-Locked Loop Circuits, Chi Zhang Jan 2006

A Study Of Phase Noise And Jitter In Submicron Cmos Phase-Locked Loop Circuits, Chi Zhang

LSU Doctoral Dissertations

Phase-locked loops (PLLs) are widely used in communication systems. With the continuously expanding of market for high speed, portable communication devices, low noise CMOS submicron integrated circuit designs of PLL for different applications are in large demand. In this dissertation, phase noise and jitter properties of PLL and its building blocks are investigated both at the physical and system levels. At the physical level, hot carrier effect in submicron MOSFETs has been considered. As one of the most dominant noise sources of PLL, the voltage-controlled oscillator (VCO) is considered when investigating the noise degradation induced by the hot carrier effect. …

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Engineering Education Through Service-Learning In Developing Communities: Two Case Studies, Evan A. Thomas, Andrew Azman Jan 2006

Engineering Education Through Service-Learning In Developing Communities: Two Case Studies, Evan A. Thomas, Andrew Azman

Mechanical and Materials Engineering Faculty Publications and Presentations

This paper provides case studies of two service learning projects that University of Colorado at Boulder (CU-Boulder) students are integrating into their academic experience. The projects focus on developing communities and are managed under the auspices of Engineers Without Borders-USA (EWB-USA), a group founded by Dr. Bernard Amadei, Professor of Civil Engineering at CU-Boulder. These projects expand students? understanding of the social value of their chosen profession, and expose them to a type of engineering significantly different than what is presented in most of their classes. Specifically, focusing on developing communities provides students with the opportunity to design solutions to …

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Thermal Sprayed Surface Coatings And Optical Characterisation, Yueqiang Xue Jan 2006

Thermal Sprayed Surface Coatings And Optical Characterisation, Yueqiang Xue

Masters

This research work aims to establish the potential of defect detection of thermal sprayed surface coatings by using a newly developed optical non-destructive interferometric technique – Electronic Speckle Pattern Shearing Interferometry (ESPSI), rather than using mechanical destructive testing methods and other non-destructive methods. This technique has been used in many industries for non-destructive testing (NDT). However, it is innovative to use this technique for NDT of thermal sprayed metal alloy coatings, especially those that are produced by flame powder spraying process. Investigations were carried out by the SUPERJET spray process, which was the flame powder spray process utilised in this …

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Calculating Static Field And Charge Distributions Using Full-Wave Boundary Element Methods, Todd H. Hubing, Haixin Ke Jan 2006

Calculating Static Field And Charge Distributions Using Full-Wave Boundary Element Methods, Todd H. Hubing, Haixin Ke

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Determination Of The Mechanical Properties Of Electrospun Gelatin Based On Polymer Concentration And Fiber Alignment, Leander Taylor Iii Jan 2006

Determination Of The Mechanical Properties Of Electrospun Gelatin Based On Polymer Concentration And Fiber Alignment, Leander Taylor Iii

Theses and Dissertations

The process of electrospinning has given the field of tissue engineering insight into many aspects of tissue engineered scaffolds, including how factors such as fiber diameter and porosity are affected by polymer concentration. However, the affects of fiber alignment upon the material properties of electrospun scaffolds remains unclear. The purpose of this study is to determine how the material properties of electrospun gelatin scaffolds are affected by changes in fiber alignment and starting gelatin concentration. Gelatin scaffolds, with starting concentrations of 80, 100, and 130mg/m1, were electrospun onto a target mandrel rotating at various speeds. Samples of each scaffold were …

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Scaffold Permeability As A Means To Determine Fiber Diameter And Pore Size Of Electrospun Fibrinogen, Scott Allen Sell Jan 2006

Scaffold Permeability As A Means To Determine Fiber Diameter And Pore Size Of Electrospun Fibrinogen, Scott Allen Sell

Theses and Dissertations

The purpose of this study was to construct a flowmeter that could accurately measure the hydraulic permeability of electrospun fibrinogen scaffolds, providing insight into the transport properties of electrospun scaffolds while making the measurement of their topographical features (fiber and pore size) more accurate. Three different concentrations of fibrinogen were used (100, 120, and 150mg/ml) to create scaffolds with three different fiber diameters and pore sizes. The fiber diameters and pore sizes of the electrospun scaffolds were analyzed through scanning electron microscopy and image analysis software. The permeability of each scaffold was measured and used to calculate permeability-based fiber diameters …

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The Effect Of Stationary Uv Excitation On The Optical Behavior Of Electrochemically Self-Assembled Semiconductor Nanowires, Rajesh A. Katkar Jan 2006

The Effect Of Stationary Uv Excitation On The Optical Behavior Of Electrochemically Self-Assembled Semiconductor Nanowires, Rajesh A. Katkar

Theses and Dissertations

In this work, we investigate the optical response of the semiconductor quantum wire array when excited by stationary UV light. The array is synthesized by selectively electro-depositing the semiconductor material in electrochemically self-assembled porous alumina templates. Our studies are based on the optical behavioral changes in CdS, ZnO, ZnSe and CdSe quantum wires of 50-, 25- and 10-nm diameters. We use a set of generalized Bloch equations to solve the interband polarization function of the semiconductors derived within the Hartree-Fock approximation, and theoretically model the UV excitation effect on the quantum wires. The solutions which consider the effects of screening, …

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Accelerating Whole-Cell Biocatalysis By Enhancing Outer Membrane Permeability, Ye Ni Jan 2006

Accelerating Whole-Cell Biocatalysis By Enhancing Outer Membrane Permeability, Ye Ni

Theses and Dissertations

Whole-cell biocatalysts are preferred in many biocatalysis applications. However, cell envelope often represents a formidable permeability barrier. As a result, reactions catalyzed by whole-cells are reportedly orders of magnitude slower than those of by their free enzyme counterparts. The present research addresses this critical issue by using membrane engineering approaches. Two E. coli strains with genetically altered outer membrane structures were used in the study, a lipopolysaccarides (LPS) mutant SM101 and a Braun's lipoprotein mutant E609L. The effects of outer membrane mutation on the permeability of substrates differing substantially in size and hydrophobicity were investigated by combining the mutant cells …

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Book Review: Digital Crime And Forensic Science In Cyberspace, Gary C. Kessler Jan 2006

Book Review: Digital Crime And Forensic Science In Cyberspace, Gary C. Kessler

Journal of Digital Forensics, Security and Law

This issue presents the first Book Review column for the JDFSL. It is an experiment to broaden the services that the journal provides to readers, so we are anxious to get your reaction. Is the column useful and interesting? Should we include more than one review per issue? Should we also review products? Do you have suggested books/products for review and/or do you want to write a review? All of this type of feedback -- and more -- is appreciated. Please feel free to send comments to Gary Kessler ([email protected]) or Glenn Dardick ([email protected]).

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Alphaco: A Teaching Case On Information Technology Audit And Security, Hüseyin Tanriverdi, Joshua Bertsch, Jonathan Harrison, Po-Ling Hsiao, Ketan S. Mesuria, David Hendrawirawan Jan 2006

Alphaco: A Teaching Case On Information Technology Audit And Security, Hüseyin Tanriverdi, Joshua Bertsch, Jonathan Harrison, Po-Ling Hsiao, Ketan S. Mesuria, David Hendrawirawan

Journal of Digital Forensics, Security and Law

Recent regulations in the United States (U.S.) such as the Sarbanes-Oxley Act of 2002 require top management of a public firm to provide reasonable assurance that they institute internal controls that minimize risks over the firm’s operations and financial reporting. External auditors are required to attest to the management’s assertions over the effectiveness of those internal controls. As firms rely more on information technology (IT) in conducting business, they also become more vulnerable to IT related risks. IT is critical for initiating, recording, processing, summarizing and reporting accurate financial and non-financial data. Thus, understanding IT related risks and instituting internal …

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Table Of Contents Jan 2006

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

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Designing A Data Warehouse For Cyber Crimes, Il-Yeol Song, John D. Maguire, Ki Jung Lee, Namyoun Choi, Xiaohua Hu, Peter Chen Jan 2006

Designing A Data Warehouse For Cyber Crimes, Il-Yeol Song, John D. Maguire, Ki Jung Lee, Namyoun Choi, Xiaohua Hu, Peter Chen

Journal of Digital Forensics, Security and Law

One of the greatest challenges facing modern society is the rising tide of cyber crimes. These crimes, since they rarely fit the model of conventional crimes, are difficult to investigate, hard to analyze, and difficult to prosecute. Collecting data in a unified framework is a mandatory step that will assist the investigator in sorting through the mountains of data. In this paper, we explore designing a dimensional model for a data warehouse that can be used in analyzing cyber crime data. We also present some interesting queries and the types of cyber crime analyses that can be performed based on …

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A Forensic Log File Extraction Tool For Icq Instant Messaging Clients, Kim Morfitt, Craig Valli Jan 2006

A Forensic Log File Extraction Tool For Icq Instant Messaging Clients, Kim Morfitt, Craig Valli

Journal of Digital Forensics, Security and Law

Instant messenger programs such as ICQ are often used by hackers and criminals for illicit purposes and consequently the log files from such programs are of interest in a forensic investigation. This paper outlines research that has resulted in the development of a tool for the extraction of ICQ log file entries. Detailed reconstruction of data from log files was achieved with a number of different ICQ software. There are several limitations with the current design including timestamp information not adjusted for the time zone, data could be altered, and conversations must be manually reconstructed. Future research will aim to …

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The Design Of An Undergraduate Degree Program In Computer & Digital Forensics, Gary C. Kessler, Michael E. Schirling Jan 2006

The Design Of An Undergraduate Degree Program In Computer & Digital Forensics, Gary C. Kessler, Michael E. Schirling

Journal of Digital Forensics, Security and Law

Champlain College formally started an undergraduate degree program in Computer & Digital Forensics in 2003. The underlying goals were that the program be multidisciplinary, bringing together the law, computer technology, and the basics of digital investigations; would be available as on online and oncampus offering; and would have a process-oriented focus. Success of this program has largely been due to working closely with practitioners, maintaining activity in events related to both industry and academia, and flexibility to respond to ever-changing needs. This paper provides an overview of how this program was conceived, developed, and implemented; its evolution over time; and …

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The Role Of Power And Negotiation In Online Deception, Chad Albrecht, Conan C. Albrecht, Jonathan Wareham, Paul Fox Jan 2006

The Role Of Power And Negotiation In Online Deception, Chad Albrecht, Conan C. Albrecht, Jonathan Wareham, Paul Fox

Journal of Digital Forensics, Security and Law

The purpose of this paper is to advance theoretical understanding of the important role of both power and negotiation during online deception. By so doing, the paper provides insight into the relationship between perpetrator and victim in Internet fraud. The growing prevalence of Internet Fraud continues to be a burden to both society and individuals. In an attempt to better understand Internet fraud and online deception, this article attempts to build an interactive model, based upon the dimensions of power and negotiation from the management and psychology literature. Using the model presented, the article examines the effects of the Internet …

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A Curriculum For Teaching Information Technology Investigative Techniques For Auditors, Grover S. Kearns Jan 2006

A Curriculum For Teaching Information Technology Investigative Techniques For Auditors, Grover S. Kearns

Journal of Digital Forensics, Security and Law

Recent prosecutions of highly publicized white-collar crimes combined with public outrage have resulted in heightened regulation of financial reporting and greater emphasis on systems of internal control. Because both white-collar and cybercrimes are usually perpetrated through computers, internal and external auditors’ knowledge of information technology (IT) is now more vital than ever. However, preserving digital evidence and investigative techniques, which can be essential to fraud examinations, are not skills frequently taught in accounting programs and instruction in the use of computer assisted auditing tools and techniques – applications that might uncover fraudulent activity – is limited. Only a few university-level …

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Concurrent Multiple- Issue Negotiation For Internet-Based Services, Jiangbo Dang, Michael N. Huhns Jan 2006

Concurrent Multiple- Issue Negotiation For Internet-Based Services, Jiangbo Dang, Michael N. Huhns

Faculty Publications

Negotiation is a technique for reaching a mutually beneficial agreement among autonomous entities. In an Internet-based services context, multiple entities are negotiating simultaneously. The concurrent negotiation protocol extends existing negotiation protocols, letting both service requestors and service providers manage several negotiation processes in parallel. Colored Petri nets, which have greater expressive power than finite state machines and offer support for concurrency, represent the negotiation protocol and facilitate the analysis of desirable properties.

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