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Electrical and Computer Engineering

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Articles 6541 - 6570 of 7208

Full-Text Articles in Computer Engineering

Maximizing Communication Concurrency Via Link-Layer Packet Salvaging In Mobile Ad Hoc Networks, Chansu Yu, Kang G. Shin, Lubo Song Apr 2007

Maximizing Communication Concurrency Via Link-Layer Packet Salvaging In Mobile Ad Hoc Networks, Chansu Yu, Kang G. Shin, Lubo Song

Electrical and Computer Engineering Faculty Publications

Carrier-sense medium access control (MAC) protocols such as the IEEE 802.11 distributed coordination function (DCF) avoid collisions by holding up pending packet transmission requests when a carrier signal is observed above a certain threshold. However, this often results in unnecessarily conservative communication, thus making it difficult to maximize the utilization of the spatial spectral resource. This paper shows that a higher aggregate throughput can be achieved by allowing more concurrent communications and adjusting the communication distance on the fly, which needs provisions for the following two areas. On the one hand, carrier sense-based MAC protocols do not allow aggressive communication …


Detecting Compromised Nodes In Wireless Sensor Networks, Mary Lisa Mathews Apr 2007

Detecting Compromised Nodes In Wireless Sensor Networks, Mary Lisa Mathews

Electrical & Computer Engineering Theses & Dissertations

While wireless sensor networks are proving to be a versatile tool, many of the applications in which they are utilized have sensitive data. Therefore, security is crucial in many of these applications. Once a sensor node has been compromised, the security of the network degrades quickly if measures are not taken to deal with this event. There have been many approaches researched to tackle the issue. In this thesis, an anomaly-based intrusion detection protocol is developed to detect compromised nodes in wireless sensor networks.

The proposed protocol is implemented after the sensors are deployed into the environment in which they …


Speech Signal Enhancement Through Adaptive Wavelet Thresholding, Michael T. Johnson, Xiaolong Yuan, Yao Ren Feb 2007

Speech Signal Enhancement Through Adaptive Wavelet Thresholding, Michael T. Johnson, Xiaolong Yuan, Yao Ren

Electrical and Computer Engineering Faculty Research and Publications

This paper demonstrates the application of the Bionic Wavelet Transform (BWT), an adaptive wavelet transform derived from a non-linear auditory model of the cochlea, to the task of speech signal enhancement. Results, measured objectively by Signal-to-Noise ratio (SNR) and Segmental SNR (SSNR) and subjectively by Mean Opinion Score (MOS), are given for additive white Gaussian noise as well as four different types of realistic noise environments. Enhancement is accomplished through the use of thresholding on the adapted BWT coefficients, and the results are compared to a variety of speech enhancement techniques, including Ephraim Malah filtering, iterative Wiener filtering, and spectral …


Study Of Soliton Stabilization In D+1 Dimensions Using Novel Analytical And Numerical Techniques, George Nehmetallah, Partha P. Banerjee Jan 2007

Study Of Soliton Stabilization In D+1 Dimensions Using Novel Analytical And Numerical Techniques, George Nehmetallah, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

In this Chapter, we provide a brief review of the underlying nonlinear Schrödinger and associated equations that model spatio-temporal propagation in one and higher dimensions in a nonlinear dispersive environment. Particular attention is given to fast adaptive numerical techniques to solve such equations, and in the presence of dispersion and nonlinearity management, saturating nonlinearity and nonparaxiality. A unique variational approach is also outlined which helps in determining the ranges of nonlinearity and dispersion parameters to ensure stable solutions of the nonlinear equations. The propagation of 3+1 dimensional spatio-temporal pulses, or optical bullets is also modeled using a fast adaptive split-step …


Atmospheric Turbulence Compensation Of Point Source Images Using Asynchronous Stochastic Parallel Gradient Descent Technique On Amos 3.6 M Telescope, Mikhail Vorontsov, Jim F. Riker, Gary W. Carhart, Venkata S. Rao Gudimetla, Leonid A. Beresnev, Thomas Weyrauch Jan 2007

Atmospheric Turbulence Compensation Of Point Source Images Using Asynchronous Stochastic Parallel Gradient Descent Technique On Amos 3.6 M Telescope, Mikhail Vorontsov, Jim F. Riker, Gary W. Carhart, Venkata S. Rao Gudimetla, Leonid A. Beresnev, Thomas Weyrauch

Electrical and Computer Engineering Faculty Publications

The Stochastic Parallel Gradient Descent Technique-based Adaptive Optics (SPGD-AO) system described in this presentation does not use a conventional wavefront sensor. It uses a metric signal collected by a single pixel detector placed behind a pinhole in the image plane to drive three deformable mirrors (DMs). The system is designed to compensate the image for turbulence effects. The theory behind this method is described in detail in [1]. However this technique, while widely simulated and tested in the laboratory, was not yet verified in astronomical field site experiments. During the month of May 2007, a series of experiments with SPGD-AO …


Adaptive Optics Performance Over Long Horizontal Paths: Aperture Effects In Multi-Conjugate Adaptive Optical Systems, Miao Yu, Mikhail Vorontsov, Svetlana Lachinova, Jim F. Riker, Venkata S. Rao Gudimetla Jan 2007

Adaptive Optics Performance Over Long Horizontal Paths: Aperture Effects In Multi-Conjugate Adaptive Optical Systems, Miao Yu, Mikhail Vorontsov, Svetlana Lachinova, Jim F. Riker, Venkata S. Rao Gudimetla

Electrical and Computer Engineering Faculty Publications

We analyze various scenarios of the aperture effects in adaptive optical receiver-type systems when inhomogeneities of the wave propagation medium are distributed over long horizontal propagation path, or localized in a few thin layers remotely located from the receiver telescope pupil. Phase aberration compensation is performed using closed-loop control architectures based on phase conjugation and decoupled stochastic parallel gradient descent (DSPGD) control algorithms. Both receiver system aperture diffraction effects and the impact of wave-front corrector position on phase aberration compensation efficiency are analyzed for adaptive systems with single or multiple wave-front correctors.


United States Patent Application Publication: System And Method For Sequence Distance Measure For Phylogenetic Tree Construction, K. Sayood, Hasan H. Otu, Steven H. Hinrichs Jan 2007

United States Patent Application Publication: System And Method For Sequence Distance Measure For Phylogenetic Tree Construction, K. Sayood, Hasan H. Otu, Steven H. Hinrichs

Department of Electrical and Computer Engineering: Faculty Publications

The present invention permits identification of biological materials following recovery of DNA using standard techniques by comparing a mathematical characterization of the unknown sequence with the mathematical characterization of DNA sequences of known genera and species. The clinical identification of infectious organisms is required for accurate diagnosis and selection of antimicrobial therapeutics. The invention allows an ab initio approach with the potential for rapid identification of biological materials of unknown origin. The approach provides for identification and classification of emergent or new organisms without previous phenotypic identification. The technique may also be used in monitoring situations where the need exists …


A Map Estimator For Simultaneous Superresolution And Detector Nonunifomity Correct, Russell C. Hardie, Douglas R. Droege Jan 2007

A Map Estimator For Simultaneous Superresolution And Detector Nonunifomity Correct, Russell C. Hardie, Douglas R. Droege

Electrical and Computer Engineering Faculty Publications

During digital video acquisition, imagery may be degraded by a number of phenomena including undersampling, blur, and noise. Many systems, particularly those containing infrared focal plane array (FPA) sensors, are also subject to detector nonuniformity. Nonuniformity, or fixed pattern noise, results from nonuniform responsivity of the photodetectors that make up the FPA. Here we propose a maximuma posteriori (MAP) estimation framework for simultaneously addressing undersampling, linear blur, additive noise, and bias nonuniformity. In particular, we jointly estimate a superresolution (SR) image and detector bias nonuniformity parameters from a sequence of observed frames. This algorithm can be applied to video in …


Securitycom: A Multi-Player Game For Researching And Teaching Information Security Teams, Douglas P. Twitchell Jan 2007

Securitycom: A Multi-Player Game For Researching And Teaching Information Security Teams, Douglas P. Twitchell

Journal of Digital Forensics, Security and Law

A major portion of government and business organizations’ attempts to counteract information security threats is teams of security personnel. These teams often consist of personnel of diverse backgrounds in specific specialties such as network administration, application development, and business administration, resulting in possible conflicts between security, functionality, and availability. This paper discusses the use of games to teach and research information security teams and outlines research to design and build a simple, team-oriented, configurable, information security game. It will be used to study how information security teams work together to defend against attacks using a multi-player game, and to study …


Table Of Contents Jan 2007

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.


Evolvable Reconfigurable Hardware Framework For Edge Detection, Nader I. Rafla Jan 2007

Evolvable Reconfigurable Hardware Framework For Edge Detection, Nader I. Rafla

Electrical and Computer Engineering Faculty Publications and Presentations

Systems on Reconfigurable Chips contain rich resources of logic, memory, and processor cores on the same fabric. This platform is suitable for implementation of Evolvable Reconfigurable Hardware Architectures (ERHA). It is based on the idea of combining reconfigurable Field Programmable Gate Arrays (FPGA) along with genetic algorithms (GA) to perform the reconfiguration operation. This architecture is a suitable candidate for implementation of early-processing stage operators of image processing such as filtering and edge detection. However, there are still fundamental issues need to be solved regarding the on-chip reprogramming of the logic. This paper presents a framework for implementing an evolvable …


An Ad Hoc Adaptive Hashing Technique For Non-Uniformly Distributed Ip Address Lookup In Computer Networks, Christopher Martinez, Wei-Ming Lin Jan 2007

An Ad Hoc Adaptive Hashing Technique For Non-Uniformly Distributed Ip Address Lookup In Computer Networks, Christopher Martinez, Wei-Ming Lin

Electrical & Computer Engineering and Computer Science Faculty Publications

Hashing algorithms have been widely adopted for fast address look-up, which involves a search through a database to find a record associated with a given key. Hashing algorithms transforms a key into a hash value hoping that the hashing renders the database a uniform distribution with respect to the hash value. The closer to uniform hash values, the less search time required for a query. When the database is key-wise uniformly distributed, any regular hashing algorithm (bit-extraction, bit-group XOR, etc.) leads to a statistically perfect uniform hash distribution. When the database has keys with a non-uniform distribution, performance of regular …


Providing A Foundation For Analysis Of Volatile Data Stores, Timothy Vidas Jan 2007

Providing A Foundation For Analysis Of Volatile Data Stores, Timothy Vidas

Journal of Digital Forensics, Security and Law

Current threats against typical computer systems demonstrate a need for forensic analysis of memory-resident data in addition to the conventional static analysis common today. Certain attacks and types of malware exist solely in memory and leave little or no evidentiary information on nonvolatile stores such as a hard disk drive. The desire to preserve system state at the time of response may even warrant memory acquisition independent of perceived threats and the ability to analyze the acquired duplicate.

Tools capable of duplicating various types of volatile data stores are becoming widely available. Once the data store has been duplicated, current …


A New Relaying Algorithm To Detect Loss Of Excitation Of Synchronous Generators, Ömer Usta, M. H. Musa, M. Bayrak, M.A. Redfern Jan 2007

A New Relaying Algorithm To Detect Loss Of Excitation Of Synchronous Generators, Ömer Usta, M. H. Musa, M. Bayrak, M.A. Redfern

Turkish Journal of Electrical Engineering and Computer Sciences

A new digital relaying algorithm is introduced for the protection of synchronous generators against loss of excitation conditions. The new algorithm is based on measuring of the 3-phase reactive power output of the machines, and monitors the direction and magnitude of leading reactive power at the generator terminal. The protection algorithm is designed such that it can provide reliable protection against loss of field conditions and remains stable during recoverable power system swing conditions. While the new relay produces a trip signal for partial loss of field conditions causing the machine to lose its stability, it remains stable for the …


A Combinatorial Approach Of Real Ga & Fuzzy To Atc Enhancement, Hossein Farahmand, Masoud Rashidinejad, Ali Akbar Gharaveici Jan 2007

A Combinatorial Approach Of Real Ga & Fuzzy To Atc Enhancement, Hossein Farahmand, Masoud Rashidinejad, Ali Akbar Gharaveici

Turkish Journal of Electrical Engineering and Computer Sciences

Under new de-regulated environment an open access to transmission system seems to be desired. Transmission system operators (TSOs) are encouraged to use the existing facilities more efficiently. This paper focuses on study of the best location for SVC as a FACTS device to improve voltage profile as well as maximum available transfer capacity (ATC) in order to achieve lower prices. Real genetic algorithm (RGA) is used for optimization technique and analytical hierarchy process (AHP) associated with fuzzy sets to obtain priority vector for each alternative to evaluate the GA fitness. The effectiveness of the proposed methodology is shown through case …


Modelling A Deposition Process In Collective Construction, Robert L. Stewart, R. Andrew Russell, Lindsay Kleeman Jan 2007

Modelling A Deposition Process In Collective Construction, Robert L. Stewart, R. Andrew Russell, Lindsay Kleeman

Turkish Journal of Electrical Engineering and Computer Sciences

During collective construction tasks, swarm robots coordinate their actions in space and time to build structures that conform to some given design or specification. In this paper, a simulation model and a mathematical model (based on a Markov chain) are introduced to describe the deposition process of a previously detailed robotic swarm system that uses templates and feedback to facilitate construction. The models are based on the behaviour and geometry of real robots and predict the dynamics observed during practical trials as well as explaining the occurrence of different spatial patterns of building blocks. Furthermore, the models provide an insight …


Swarm Robot Systems Based On The Evolution Of Personality Traits, Sidney Nascimento Givigi Jr. Jan 2007

Swarm Robot Systems Based On The Evolution Of Personality Traits, Sidney Nascimento Givigi Jr.

Turkish Journal of Electrical Engineering and Computer Sciences

Game theory may be very useful in modeling and analyzing swarms of robots. Using game theory in conjunction with traits of personalities, we achieve intelligent swarm robots. Traits of personality are characteristics of each robot that define the robots' behaviours. The environment is represented as a game and due to the evolution of the traits through a learning process, we show how the robots may react intelligently to changes in the environment. A proof of convergence for the proposed algorithm is offered. The process of selection of traits is discussed and the potential of the modeling is demonstrated in several …


Swarms In Biology And Engineering, Kevin M. Passino Jan 2007

Swarms In Biology And Engineering, Kevin M. Passino

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.


Optimal Location For Shunt Connected Facts Devices In A Series Compensated Long Transmission Line, P.R. Sharma, Ashok Kumar, Narender Kumar Jan 2007

Optimal Location For Shunt Connected Facts Devices In A Series Compensated Long Transmission Line, P.R. Sharma, Ashok Kumar, Narender Kumar

Turkish Journal of Electrical Engineering and Computer Sciences

Shunt FACTS devices are used for controlling transmission voltage, power flow, reducing reactive losses, and damping of power system oscillations for high power transfer levels. In this paper the optimal location of a shunt FACT device is investigated for an actual line model of a transmission line having series compensation at the center. Effect of change in degree of series compensation on the optimal location of the shunt FACTS device to get the highest possible benefit is studied. It is found that the optimal location of the shunt FACTS device varies with the change in the level of series compensation …


A Grounded Theory Approach To Identifying And Measuring Forensic Data Acquisition Tasks, Gregory H. Carlton Jan 2007

A Grounded Theory Approach To Identifying And Measuring Forensic Data Acquisition Tasks, Gregory H. Carlton

Journal of Digital Forensics, Security and Law

As a relatively new field of study, little empirical research has been conducted pertaining to computer forensics. This lack of empirical research contributes to problems for practitioners and academics alike.

For the community of practitioners, problems arise from the dilemma of applying scientific methods to legal matters based on anecdotal training methods, and the academic community is hampered by a lack of theory in this evolving field. A research study utilizing a multi-method approach to identify and measure tasks practitioners perform during forensic data acquisitions and lay a foundation for academic theory development was conducted in 2006 in conjunction with …


Information Governance: A Model For Security In Medical Practice, Patricia A. Williams Jan 2007

Information Governance: A Model For Security In Medical Practice, Patricia A. Williams

Journal of Digital Forensics, Security and Law

Information governance is becoming an important aspect of organisational accountability. In consideration that information is an integral asset of most organisations, the protection of this asset will increasingly rely on organisational capabilities in security. In the medical arena this information is primarily sensitive patient-based information. Previous research has shown that application of security measures is a low priority for primary care medical practice and that awareness of the risks are seriously underestimated. Consequently, information security governance will be a key issue for medical practice in the future. Information security governance is a relatively new term and there is little existing …


Book Review: Conquest In Cyberspace: National Security And Information Warfare, Gary C. Kessler Jan 2007

Book Review: Conquest In Cyberspace: National Security And Information Warfare, Gary C. Kessler

Journal of Digital Forensics, Security and Law

This is the 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]).


Information Technology Act 2000 In India - Authentication Of E-Documents, R. G. Pawar, B. S. Sawant, A. Kaiwade Jan 2007

Information Technology Act 2000 In India - Authentication Of E-Documents, R. G. Pawar, B. S. Sawant, A. Kaiwade

Journal of Digital Forensics, Security and Law

The Information Technology Act 2000 has enacted in India on 9th June 2000. This Act has mentioned provision of authentication of electronic document. It is the need of hour at that time that such provision is needed in the Indian Law system, especially for electronic commerce and electronic governance. Electronic commerce”, which involve the use of alternatives to paper based methods of communication and storage information. To do electronic commerce there should be authentication of particular document. The working of internet is the documents are traveling in terms of bits from one destination to other destination, through various media like …


Monitoring And Surveillance In The Workplace: Lessons Learnt? – Investigating The International Legal Position, Verine Etsebeth Jan 2007

Monitoring And Surveillance In The Workplace: Lessons Learnt? – Investigating The International Legal Position, Verine Etsebeth

Journal of Digital Forensics, Security and Law

When considering the legal implications of monitoring and surveillance in the workplace, the question may be asked why companies deploy computer surveillance and monitoring in the first place. Several reasons may be put forward to justify why more than 80% of all major American firms monitor employee e-mails and Internet usage. However, what most companies forget is the fact that the absence or presence of monitoring and surveillance activities in a company holds serious legal consequences for companies. From the discussion in this paper it will become apparent that there is a vast difference in how most countries approach this …


Education Organization Baseline Control Protection And Trusted Level Security, Wasim A. Al-Hamdani Jan 2007

Education Organization Baseline Control Protection And Trusted Level Security, Wasim A. Al-Hamdani

Journal of Digital Forensics, Security and Law

Many education organizations have adopted for security the enterprise best practices for implementation on their campuses, while others focus on ISO Standard (or/and) the National Institution of Standards and Technology.

All these adoptions are dependent on IT personal and their experiences or knowledge of the standard. On top of this is the size of the education organizations. The larger the population in an education organization, the more the problem of information and security become very clear. Thus, they have been obliged to comply with information security issues and adopt the national or international standard. The case is quite different when …


Network And Database Security: Regulatory Compliance, Network, And Database Security - A Unified Process And Goal, Errol A. Blake Jan 2007

Network And Database Security: Regulatory Compliance, Network, And Database Security - A Unified Process And Goal, Errol A. Blake

Journal of Digital Forensics, Security and Law

Database security has evolved; data security professionals have developed numerous techniques and approaches to assure data confidentiality, integrity, and availability. This paper will show that the Traditional Database Security, which has focused primarily on creating user accounts and managing user privileges to database objects are not enough to protect data confidentiality, integrity, and availability. This paper is a compilation of different journals, articles and classroom discussions will focus on unifying the process of securing data or information whether it is in use, in storage or being transmitted. Promoting a change in Database Curriculum Development trends may also play a role …


Book Review: No Place To Hide, Gary C. Kessler Jan 2007

Book Review: No Place To Hide, Gary C. Kessler

Journal of Digital Forensics, Security and Law

This issue presents the second 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]).


The Evolution Of Internet Legal Regulation In Addressing Crime And Terrorism, Murdoch Watney Jan 2007

The Evolution Of Internet Legal Regulation In Addressing Crime And Terrorism, Murdoch Watney

Journal of Digital Forensics, Security and Law

Internet regulation has evolved from self-regulation to the criminalization of conduct to state control of information available, accessed and submitted. Criticism has been leveled at the different forms of state control and the methods employed to enforce state control. After the terrorist attack on the USA on 11 September 2001, governments justify Internet state control as a law enforcement and national security tool against the abuse and misuse of the Internet for the commission of serious crimes, such as phishing, child pornography; terrorism and copyright infringement. Some Internet users and civil rights groups perceive state control as an abomination which …


Computer Crimes: A Case Study Of What Malaysia Can Learn From Others?, Janaletchumi Appudurai, Chitra L. Ramalingam Jan 2007

Computer Crimes: A Case Study Of What Malaysia Can Learn From Others?, Janaletchumi Appudurai, Chitra L. Ramalingam

Journal of Digital Forensics, Security and Law

Rapid development of information technology (IT) has brought with it many new applications such as e-commerce and global business. The past few years have seen activities in the legislative arena covering issues such as digital signatures, the international recognition of electronic documents and privacy and data protection. Both the developed and developing countries have exhibited keenness to embrace the IT environment. Securing this electronic environment from intrusion, however, continues to be problematic. A particular favorite form of computer crime would be ‘hacking’. As more computer systems move on to on-line processing and improved telecommunications, computer hackers are now a real …


C-Fos As A Proapoptotic Agent In Trail-Induced Apoptosis In Prostate Cancer Cells, Xiaoping Zhang, Liang Zhang, Hongmei Yang, Xu Huang, Hasan H. Otu, Towia A. Libermann, William C. Dewolf, Roya Khosravi-Far, Aria F. Olumi Jan 2007

C-Fos As A Proapoptotic Agent In Trail-Induced Apoptosis In Prostate Cancer Cells, Xiaoping Zhang, Liang Zhang, Hongmei Yang, Xu Huang, Hasan H. Otu, Towia A. Libermann, William C. Dewolf, Roya Khosravi-Far, Aria F. Olumi

Department of Electrical and Computer Engineering: Faculty Publications

Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL)/Apo-2L promotes apoptosis in cancer cells while sparing normal cells. Although many cancers are sensitive to TRAIL-induced apoptosis, some evade the proapoptotic effects of TRAIL. Therefore, differentiating molecular mechanisms that distinguish between TRAIL-sensitive and TRAIL-resistant tumors are essential for effective cancer therapies. Here, we show that c-Fos functions as a proapoptotic agent by repressing the antiapoptotic molecule c-FLIP(L). c-Fos binds the c-FLIP(L) promoter, represses its transcriptional activity, and reduces c-FLIP(L) mRNA and protein levels. Therefore, c-Fos is a key regulator of c-FLIP(L), and activation of c-Fos determines whether a cancer cell will undergo cell death …