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Articles 151 - 180 of 206

Full-Text Articles in Systems and Communications

Economic Optimization Of Offshore Wind Farms Using The Geometric Algorithm, Mahidhar Nandigam Oct 2010

Economic Optimization Of Offshore Wind Farms Using The Geometric Algorithm, Mahidhar Nandigam

Electrical & Computer Engineering Theses & Dissertations

The research project related to this thesis focuses on the optimization of electrical systems for offshore wind farms for a given capacity. The optimal design and planning is a critical issue for developing cost effectively Offshore Wind Farms in energy systems. The Geometric Optimization Algorithms approach has been adopted to develop an optimization program, where the main components of the electrical system of an offshore wind farm and key technical specifications are used as parameters to be optimized for a minimum cost with necessary constraints. The effectiveness of the optimization program can be evaluated with real-time comparison between offshore wind …


Development Of A Methodology For Customizing Insider Threat Auditing On A Linux Operating System, William T. Bai Mar 2010

Development Of A Methodology For Customizing Insider Threat Auditing On A Linux Operating System, William T. Bai

Theses and Dissertations

Insider threats can pose a great risk to organizations and by their very nature are difficult to protect against. Auditing and system logging are capabilities present in most operating systems and can be used for detecting insider activity. However, current auditing methods are typically applied in a haphazard way, if at all, and are not conducive to contributing to an effective insider threat security policy. This research develops a methodology for designing a customized auditing and logging template for a Linux operating system. An intent-based insider threat risk assessment methodology is presented to create use case scenarios tailored to address …


A Smart-Phone Application For Improving Communication Skills In Children With Autism, Lakshmi Padmaja Battagiri Oct 2009

A Smart-Phone Application For Improving Communication Skills In Children With Autism, Lakshmi Padmaja Battagiri

Electrical & Computer Engineering Theses & Dissertations

The prevalence of autism, a complex neurobiological disorder, has grown at a staggering rate in the recent past. Today, one out of 150 American children is diagnosed with autism. Generally, the disorder appears during an individual's first three years of life of and persists through his/her entire life span. The individual faces various social interaction, communication and behavioral problems. Developmental disabilities, extreme withdrawal, lack of social behaviour, severe language and attention deficits, repetitive behaviours and limited interests are the characteristics of this disorder. There is no verified cure yet, but several therapies and intervention systems especially focused on the early …


A Simulation Study Of Convergence Speed For Distributed Codeword Adaptation Algorithms In Cdma Wireless Systems, Sahana Maharjan Jul 2009

A Simulation Study Of Convergence Speed For Distributed Codeword Adaptation Algorithms In Cdma Wireless Systems, Sahana Maharjan

Electrical & Computer Engineering Theses & Dissertations

In this thesis we present a side-by-side comparison of interference avoidance (IA) algorithms for distributed codeword adaptation in Code Division Multiple Access (CDMA) systems. In CDMA systems, the interference is determined by the values of the cross-correlation of codewords assigned to users, and various algorithms can be used for codeword optimization. The IA algorithms for codeword adaptation considered are the eigen-algorithm, the Minimum Mean Square Error (MMSE) update, and the adaptive IA algorithm, for which we investigate convergence speed using the extensive simulations of several uplink CDMA system scenarios. The results of this thesis were presented at the Fourth IEEE …


Dynamic Network Formation Using Ant Colony Optimization, Steven C. Oimoen Mar 2009

Dynamic Network Formation Using Ant Colony Optimization, Steven C. Oimoen

Theses and Dissertations

Military and industry are moving toward every device being network enabled and connected for reliable availability of communication and information. To make this type of system a reality, the devices must be capable of forming a network topology on their own in a dynamic environment to ensure that the correct information reaches a desired location and on-time. This research presents three contributions for solving highly dynamic (i.e. drastic change within the network) Multi-commodity Capacitated Network Design Problems (MCNDPs) resulting in a distributed multi-agent network design algorithm. The first contribution incorporates an Ant Colony Optimization (ACO) algorithm Ant Colony System (ACS) …


Design And Development Of A Prototype For A Web-Based Interface For Online Material For Tanzanian Youth, Mjema A.M Dec 2008

Design And Development Of A Prototype For A Web-Based Interface For Online Material For Tanzanian Youth, Mjema A.M

Tanzania Journal of Engineering and Technology (TJET)

A prototype of a web-based interface for an online database was developed to be used by youth organizations in Dar-es-Salaam. A participatory approach involving secondary students in the identification of user interface requirements, in designing and testing the prototype was used. A questionnaire was designed and manned in seven secondary schools in Dar-es-Salaam to estimate the Internet usage. Interviews were conducted to countercheck the questionnaire responses. The interview and the questionnaire helped to come up with a set of user requirements for the web-based interface of an online information search. From the specifications of the user requirements the author was …


Improving The Availability Of Manufacturability Information Through Decentralization Of Process Planning, Eliab Opiyo Jun 2008

Improving The Availability Of Manufacturability Information Through Decentralization Of Process Planning, Eliab Opiyo

Tanzania Journal of Engineering and Technology (TJET)

Process planning is part of the general product development and production process that usually follows design and precedes manufacturing. Manufacturability and process planning information in general play central role in many product development and production activities, including paradoxically, conceptual and detail design - the activities that take place before process planning. The need of conducting some of the process planning activities formally before or during design is thus rather obvious. One of the main research issues is therefore the identification of the process planning activities that can be performed before the traditional process planning phase and handling of the process …


Open Source Software In Health Information Systems: Opportunities And Challenges, Hashim Twaakyondo Jun 2008

Open Source Software In Health Information Systems: Opportunities And Challenges, Hashim Twaakyondo

Tanzania Journal of Engineering and Technology (TJET)

The paper presents results of a study seeking to identify constraining and motivating factors associated with the adoption and use of Free Open Source Software to computerise health Information Systems in a developing country. The study approach is interpretive research to case study with a triangulation of several qualitative data collection methods such as interviews, group discussions and document analysis. The findings indicate that using open source software has advantages and disadvantages. The advantages are low entry cost to adopting software, possibilities of software localization, avoiding being hostage of proprietary software and foster knowledge acquisition among software developers. The disadvantages …


A Secure And Efficient Communications Architecture For Global Information Grid Users Via Cooperating Space Assets, Victor P. Hubenko Jr. Jun 2008

A Secure And Efficient Communications Architecture For Global Information Grid Users Via Cooperating Space Assets, Victor P. Hubenko Jr.

Theses and Dissertations

With the Information Age in full and rapid development, users expect to have global, seamless, ubiquitous, secure, and efficient communications capable of providing access to real-time applications and collaboration. The United States Department of Defense’s (DoD) Network-Centric Enterprise Services initiative, along with the notion of pushing the “power to the edge,” aims to provide end-users with maximum situational awareness, a comprehensive view of the battlespace, all within a secure networking environment. Building from previous AFIT research efforts, this research developed a novel security framework architecture to address the lack of efficient and scalable secure multicasting in the low earth orbit …


Lightweight Objective Quality Of Voice Estimation Through Machine Learning, Daniel Riordan Jan 2008

Lightweight Objective Quality Of Voice Estimation Through Machine Learning, Daniel Riordan

Theses

Communication systems are undergoing constant and rapid innovation, both at the design stage and in the field. This in turn has led to an inereasing need for fast, efficient, portable and economic methods for the testing of these systems. For voice carrying communication systems the quality of the transmitted voice that the system produces is a large factor in the overall performance rating of the system. This measure is known as the ‘Quality of Voice’ (QoV) and can be evaluated either subjectively or objectively.

Speech quality is a complex subjective phenomenon that can be best quantified by subjective testing. A …


A Distributed Ai Approach For Large-Scale Wlan Design, Alan Mcgibney Jan 2008

A Distributed Ai Approach For Large-Scale Wlan Design, Alan Mcgibney

Theses

The recent dramatic trend towards always-on-connectivity has driven the need for mobile ubiquitous computing environments with the advent of the Wireless Local Area Network (WLAN) seeing a shift from traditional wired networks to wireless networking. A WLAN typically contains a number of access points that allow wireless enabled clients access information and network resources such as the internet without the need for wires, offering flexibility and mobility to the users. Initial wireless networks were convenience based allowing users access to the primary wired network, and involved little planning prior to roll-out. The proliferation of low cost wireless devices combined wdth …


Covert Encryption And Document Authentication Using Texture Coding, Jonathan Blackledge, Mary Hallot Jan 2008

Covert Encryption And Document Authentication Using Texture Coding, Jonathan Blackledge, Mary Hallot

Articles

With the improvements in the quality of Commercial-Off-The-Shelf (COTS) printing and scanning devices, the ability to counterfeit documents has become a widespread problem. Consequently, there has been an increasing demand to develop digital watermarking techniques which can be applied to both electronic and printed images (and documents) that can be authenticated, prevent unauthorized copying and withstand abuse and degradation. In this paper , a new approach to digital watermarking is presented and a range of possible applications are considered. The process is defined by using concepts and techniques borrowed from Cryptography. It is based on computing a 'scramble image' by …


Reed-Solomon Codes Construction & Decoding, Samuel J. Parsons Dec 2007

Reed-Solomon Codes Construction & Decoding, Samuel J. Parsons

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.


Distributed Cluster-Based Outlier Detection In Wireless Sensor Networks, Swetha Gali Oct 2007

Distributed Cluster-Based Outlier Detection In Wireless Sensor Networks, Swetha Gali

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks find several potential applications in a variety of fields, such as environmental monitoring and control, battlefields, surveillance, smart buildings, human health monitoring, etc. These sensor networks consist of a large number of very tiny, inexpensive, and low power sensor nodes, which are deployed in a variety of harsh environments that may result in the sensor data getting corrupted. It is thus critical to detect and report these abnormal values in the sensor data, in order to have a better understanding of the monitored environment. Detection of the abnormal values is of special interest for the sensor network …


Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet Apr 2007

Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet

Electrical & Computer Engineering Theses & Dissertations

Wireless Local Area networks (WLAN) and Wireless Personal Area Networks (WPAN) provide complimentary services using the same unlicensed radio frequency band of operation. The 802.11b WLAN operates in the 2.4 GHz band and uses a Direct Sequence Spread Spectrum technique. It is designed to cover large areas ranging up to 100 meters in diameter, which may connect hundreds of computers. Bluetooth (BT) WPAN also operates in the same frequency band as the IEEE 802.lib and it uses a Frequency Hopping Spread Spectrum technique. BT is primarily used for communications between notebooks, palm units and other personal computing devices within relatively …


Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow Jan 2007

Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow

Inquiry: The University of Arkansas Undergraduate Research Journal

Data logging capability of a previously developed self contained cough recorder using an accelerometer as the sensing element is improved by using a secure digital memory card for later retrieval on a computer. Firmware is developed to enhance the functionality of the cough recorder. Existing libraries are modified for increased write rates. Increased writing speed allows 8-bit sampling at rates exceeding 8kHz, allowing for detailed time and frequency domain analysis. Additional features have also been developed to enable easy management of recordings, such as a file system compatibility with Microsoft Windows., and unique file names for each recording.


Fault Arrangements And Their Effect On The Performance Of Wireless Sensor Networks, Dwayne Sayone Blai Oct 2006

Fault Arrangements And Their Effect On The Performance Of Wireless Sensor Networks, Dwayne Sayone Blai

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks face many reliability challenges. The networks are deployed in open, hostile environments, making them easily susceptible to network failure. As a result, there are countless faults that can occur in sensor networks, from component failure to outside attacks. Outside attacks take place when an adversary gains control over a node or set of nodes in the network. Outside attackers can destroy a network in numerous ways such as random attacks, clustering attacks, search-based attacks, etc. The method and strategy used in each of these attacks directly affects the network's reliability. Understanding how these adversaries are positioned is …


An Operational Model For Mobile Sensor Cloud Management, Indrajeet Kalyankar Jul 2006

An Operational Model For Mobile Sensor Cloud Management, Indrajeet Kalyankar

Electrical & Computer Engineering Theses & Dissertations

Mobile sensors provide a safe, cost effective method for gathering information in hazardous environments. When the hazardous environment is either unexplored, such as the surface of Mars, or unanticipated, such as the result of chemical contamination, it is desirable for a system to gather information with a minimal amount of outside control (localization, decision control, etc.) and prepositioned sensors. If one takes a look at the number of the sensors deployed on a scale, at the lower end is the sole, multipurpose sensor unit. The upper end deals with hordes of inexpensive, expendable sensors. In the middle, a cluster of …


Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor Jun 2006

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …


Mobius: An Omnidirectional Robotic Platform And Software Architecture For Network Teleoperation, Samuel Aaron Miller Apr 2006

Mobius: An Omnidirectional Robotic Platform And Software Architecture For Network Teleoperation, Samuel Aaron Miller

Electrical & Computer Engineering Theses & Dissertations

The following thesis presents the results of a project to develop and test an omnidirectional robotic system (hardware and software) at NASA Langley Research Center's Robotics and Intelligent Machines Lab. The impetus for the project was the unique capabilities of omnidirectional systems. Some of the many potential benefits these systems have include improved material-handling capabilities in constrained environments (such as might be found in extraterrestrial manned habitats), efficient camera-based vehicle teleoperation, and simplified route planning for autonomous robot operations.

The project's focus was to design, build, and test a system that used Mecanum wheels to achieve omnidirectional motion. In addition …


Clarifying The Role Of Self-Efficacy And Metacognition As Indicators Of Learning: Construct Development And Test, Trevor T. Moores, Jerry Cha-Jan Chang, Deborah K. Smith Apr 2006

Clarifying The Role Of Self-Efficacy And Metacognition As Indicators Of Learning: Construct Development And Test, Trevor T. Moores, Jerry Cha-Jan Chang, Deborah K. Smith

Management, Entrepreneurship and Technology Faculty Research

We propose extending our understanding of self-efficacy by comparing self-efficacy with a related construct called metacognition. Metacognition involves the monitoring and control of one's thought processes and is often related, as is self-efficacy, to performance on a task. We develop an instrument that attempts to measure both self-efficacy and metacognition with respect to one's performance on a test covering declarative and procedural knowledge (knowing that, and knowing how) of DFDs and ERDs. With data collected from a sample of 124 students, we use partial least squares (PLS) to show that self-efficacy and metacognition are distinct yet related constructs. While self-efficacy …


The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar Apr 2006

The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar

Electrical & Computer Engineering Theses & Dissertations

The wireless computer networks have an uncertainty in their structures aside from their big advantages for the users. The environmental conditions, changing locations of the mobile hosts and the changing components in the system can easily affect their reliability. In order to know a system capability performing its functions, keep the reliability at a certain level and/or detect the deficiency of the system, it is necessary to analyze the reliability of a computer communication network including the wired and wireless parts. But the above reasons also make the analysis and a unique solution difficult so a set of algorithms is …


Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng Jan 2006

Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng

Electrical & Computer Engineering Faculty Research

Combined input and output queuing (CIOQ) switches are being considered as high-performance switch architectures due to their ability to achieve 100% throughput and perfectly emulate output queuing (OQ) switch performance with a small speedup factor S. To realize a speedup factor S, a conventional CIOQ switch requires the switching fabric and memories to operate S times faster than the line rate. In this paper, we propose to use a CIOQ switch with space-division multiplexing expansion and grouped input/output ports (SDMG CIOQ switch for short) to realize speedup while only requiring the switching fabric and memories to operate at the line …


Robust And Efficient Localization Techniques For Cellular And Wireless Sensor Networks, Haseebulla M. Khan Dec 2005

Robust And Efficient Localization Techniques For Cellular And Wireless Sensor Networks, Haseebulla M. Khan

Computer Science Theses & Dissertations

Localization in wireless networks refers to a collection of tasks that, collectively, determines the location of a mobile user, striving to hide the effects of mobility from the user and/or application. Localization has become an important issue and has drawn considerable attention, as many applications including E-911, cargo tracking, locating patients, location-sensitive billing, etc., require knowledge of the location of user/objects. It was realized, quite a while back, that extending emergency 911-like services (E-911) to continually growing mobile population is one of the extremely important localization applications. The bulk of the proposed solutions to emergency location management in wireless environments …


Knowledge Representation, Organization, And Formalization For Simulation Modeling Of Discrete Manufacturing System, Jung Hung Ma Aug 2005

Knowledge Representation, Organization, And Formalization For Simulation Modeling Of Discrete Manufacturing System, Jung Hung Ma

All-Inclusive List of Electronic Theses and Dissertations

Simulation is an useful tool that helps managers making decision by designing models for real systems. It helps companies to study behaviors of real systems hy analyzing computer models and improve the systems based on the experiments' results. However, cross-domain knowledge requirement and lack of tools facilitate modeling are the main reasons that make industries hesitate to use simulation to assist making decision. This research is an attempt to develop robust knowledge representations for discrete manufacturing system and conceptual simulation model. A modeling methodology was proposed to utilize these knowledge representations (KRs) for developing conceptual simulation models from application domain …


Mobility-Pattern Based Localization Update Algorithm For Mobile Wireless Sensor Networks, Mohammad Yacoub Al-Laho Jul 2005

Mobility-Pattern Based Localization Update Algorithm For Mobile Wireless Sensor Networks, Mohammad Yacoub Al-Laho

Electrical & Computer Engineering Theses & Dissertations

In mobile wireless sensor networks, sensors move in the monitored area at any direction and speed. Unlike many other networking hosts, sensor nodes do not have global addresses. They are often identified by using a location-based addressing scheme. Therefore, it is important to have the knowledge of the sensor location indicating where the data came from. In this thesis, three localization update algorithms were designed, Specifically, a sensor movement is divided into three states: Pause, Linear, and Random. Each state adopts different localization update algorithm. Since complex movement involves different mobility patterns, a state transition model is developed to …


Programmable Process Flow Networks, Filip D. Cuckov Apr 2005

Programmable Process Flow Networks, Filip D. Cuckov

Electrical & Computer Engineering Theses & Dissertations

A model that introduces programmability to processes occurring in a cargo terminal simulation through the use of a process language is presented in this thesis. The model provides a means for a straight-forward definition, and redefinition of changing processes, their incorporation in the simulation architecture and efficient execution. The model was built to investigate a solution for transforming the cargo terminal simulation CPortS into a process-oriented simulation without hard-coded processes. The approach taken separates the system into an architecture and a set of processes which utilize and interact with the architecture's resources and infrastructure. The processes that take place within …


Energy-Efficient Self-Organization Protocols For Sensor Networks, Qingwen Xu Jan 2005

Energy-Efficient Self-Organization Protocols For Sensor Networks, Qingwen Xu

Computer Science Theses & Dissertations

A Wireless Sensor Network (WSN, for short) consists of a large number of very small sensor devices deployed in an area of interest for gathering and delivery information. The fundamental goal of a WSN is to produce, over an extended period of time, global information from local data obtained by individual sensors. The WSN technology will have a significant impact on a wide array of applications on the efficiency of many civilian and military applications including combat field surveillance, intrusion detection, disaster management among many others. The basic management problem in the WSN is to balance the utility of the …


Information And Communication Technology Applications In The Tanzanian Health Sector, M Victor Dec 2004

Information And Communication Technology Applications In The Tanzanian Health Sector, M Victor

Tanzania Journal of Engineering and Technology (TJET)

The potential role of Information and Communication Technology (ICT) in the health sector is to improve the delivery of health services and would also help to deal with major constraints in uplifting the health standards Of Tanzanians. ICT in heath can be used to facilitate remote consultation, diagnosis and treatment. The objective Of the study was exploratory in nature and aimed at determining the awareness level of the länzanian health sector on various ICT applications which could be used in the sector. The study also aimed ar establishing the challenges to the implementation of ICT in the Tanzanian health sector. …


Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga Oct 2004

Hierarchical Hybrid Multicast An End System Multicast Algorithm Approach, Guillermo Loaisiga

Electrical & Computer Engineering Theses & Dissertations

Due to the rapid development in the computer and communication technologies, the Internet is experiencing an increasing demand of high-speed, real-time distributed applications, such as live streaming multimedia, videoconferencing, distributed simulations, and multiparty games. Multicast is an efficient transmission mechanism to support these applications. Historically, IP Multicast (IPM) has provided multicast support with well-known benefits, especially in bandwidth savings. However, it has experienced little deployment due to economic and architectural limitations.

Overlay multicast holds promise for the implementation of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. This concept …