Digital Communications and Networking Commons^™

A Three-Dimensional Pattern-Space Representation For Volumetric Arrays, William C. Barott, Paul G. Steffes

Publications

A three-dimensional pattern-space representation is presented for volumetric arrays. In this representation, the radiation pattern of an array is formed by the evaluation of the three-dimensional pattern-space on a spherical surface. The scan angle of the array determines the position of this surface within the pattern-space. This pattern-space representation is used in conjunction with a genetic algorithm to minimize the sidelobe levels exhibited by a thinned volumetric array during scanning.

Optimisation Of Multicast Routing In Wireless Mesh Networks, Brian Keegan, Karol Kowalik, Mark Davis

Conference papers

In recent years Wireless Mesh Networks have been deployed and grown in popularity in many metropolitan areas. The deployment of such networks has allowed clients to gain access to publicly available broadband networks. The implementation of wireless mesh networks requires that backhaul services (traditionally carried by wired networks) be maintained via wireless mesh points. Because of their structure, wireless mesh networks provide an excellent means for targeting a large group of end users or simply to relay data. This may be achieved by means of broadcasting or more specifically multicasting. The lack of standards and support for multicasting over wireless …

Biomarker Identification For Prostate Cancer Using An Efficient Feature Selection Algorithm, Vamsi Krishnam Raju Mantena

Electrical & Computer Engineering Theses & Dissertations

In recent years, there has been an increased interest in using protein mass spectrometry to identify biomarkers that discriminate diseased from healthy individuals. A biomarker is a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathological processes, or pharmacological responses to a therapeutic intervention. Identifying biomarkers will be an important step towards disease characterization and patient management. One challenge of biomarker identification is how to handle the high dimensional mass spectral data. In this thesis, we applied an efficient feature selection algorithm to mass spectrometry data obtained from prostate tissue samples to identify prostate …

Using Timed-Release Cryptography To Mitigate Preservation Risk Of Embargo Periods, Rabia Haq

Computer Science Theses & Dissertations

This research defines Time-Locked Embargo, a framework designed to mitigate the Preservation Risk Interval: the preservation risk associated with embargoed scholarly material. Due to temporary access restrictions, embargoed data cannot be distributed freely and thus preserved via data refreshing during the embargo time interval. A solution to mitigate the risk of data loss has been developed by suggesting a data dissemination framework that allows data refreshing of encrypted instances of embargoed content in an open, unrestricted scholarly community. This framework has been developed by exploiting implementations of existing technologies to"time-lock" data using Timed-Release Cryptology (TRC) so that it can be …

An Agent-Based Combat Simulation Framework In Support Of Effect-Based And Net-Centric Evaluation, Robert Joseph Bowen

Computational Modeling & Simulation Engineering Theses & Dissertations

The use of information technologies (IT) and information networks has proliferated in industry as a method to achieve competitive advantage. The U.S. Military and its allies, in recent years, have employed IT to improve the way they conduct operations, speed decision making, and increase the span of control of commanders. This has resulted in a fundamental shift in the way military commanders employ combat units today. These (Information Age) forces no longer have to be able to see each other or even communicate directly in order to synchronize maneuvers. Dispersion is now favored over mass, relying on the IT network …

The Interactive Research Guide: Will Function Bring Users Content? A Project Model Illustrated By A Proposed Paper-Writing Guide, Barry J. Bailey

Library Papers and Presentations

After reviewing the history of subject guides and their movement into an electronic format, their is an opportunity to change the format of information providing. Whereas a user goes to guides for lists of content, perhaps a user can go to guides to execute a function. By walking through the creation of a paper-writing guide, this idea of a functioning guide is illustrated.

Building A Blog From Scratch, Jonathan Bacon

SIDLIT Conference Proceedings

The presenter takes the audience step-by-step through the creation of a Weblog, a tool which can be used for distance education.

Key Factors In Tag Recognition For Rfid System, Nachiketa Das

Computer Science and Computer Engineering Undergraduate Honors Theses

The research effort described here was a study of factors that affect the efficiency of a Radio Frequency Identification (RFID) system in reading a certain type of commonly used passive RFID tag ('Squiggle' by Alien Technologies). The two sets of experiments conducted under this study focus on two response variables namely: readability and read rate. The factors in focus are distance between antenna and tags, the number and combinations of tags simultaneously read by the system and position of the tags left or right of the center of the antenna. Two separate experimental setups as explained in the following sections …

E-Transcript Web Services System Supporting Dynamic Conversion Between Xml And Edi, Myungjae Kwak '11, Woohyun Kang '14, Gondy Leroy, Samir Chatterjee

CGU Faculty Publications and Research

As XML becomes a standard for communications between distributed heterogeneous machines, many schools plan to implement Web Services systems using the XML e-transcript (electronic transcript) standard. We propose a framework that supports both XML e-transcript Web Services and existing EDI e-transcript systems. The framework uses the workflow engine to exploit the benefits of workflow management mechanisms. The workflow engine manages the e-transcript business process by enacting and completing the tasks and sub-processes within the main business process. We implemented the proposed framework by using various open source projects including Java, Eclipse, and Apache Software Foundation’s Web Services projects. Compared with …

Performance Of Adaptive Wireless Systems With Feedback, Sirisha Koduri

Electrical & Computer Engineering Theses & Dissertations

Future generations of wireless systems will employ versatile transmitters and receivers based on software defined radios that are capable of adapting in response to changes in the operating environment to meet the specified quality of service requirements. In adaptive wireless systems, transmitters use feedback from the receiver to update characteristics of the transmitted signal to changing patterns of interference. In this thesis, the performance of transmitter adaptation algorithms with limited feedback and the system performance as a function in which the interference information is quantized for transmission over the feedback channel are analyzed. The results of this thesis were presented …

Immersive Active Learning For Virtual Laboratory Experiments, Swetha Punnandla

Electrical & Computer Engineering Theses & Dissertations

A Laboratory Immersive Interactive Virtual Environment (LIIVE) for scientific experiments is developed using MAY A and Virtools. The LIIVE is used as a pre-lab practice module to familiarize the students with the equipment, procedure and parameters involved in a laboratory experiment. The system has been assessed for its effectiveness as a learning tool by administering a project and a quiz to each participant and conducting a structured observation during the actual laboratory experiment on the real equipment. The learning effect achieved by the LIIVE is compared to the learning effects obtained by the less immersive 2D virtual environment and the …

Congestion Mitigation In Wireless Sensor Networks Using Single-Hop Backpressure Algorithm, Vijay Shekar Mangilipalli Gangu Sham

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks consist of a group of small components with limited resources allocated to sense the environment and transmit data to the user or interpreter. This concept is technically evolved from Sensors that are basically used to sense the environment around and collect data based on the sensing application incorporated in them. An extension to functionality of the sensors leads to the concept of sensor networks, where, in addition to gathering information at individual sensors, the data is processed and transmitted to a central station or Base station. This concept of transmitting the information from one node to the …

Extending The Network Life Time In Wsn Using Energy Efficient Algorithm, Venkata Sesha Sai Koundinya Goparaju

Electrical & Computer Engineering Theses & Dissertations

Wireless Sensor networks have many potential applications. These wireless sensor networks necessitate specific design requirements of which energy efficiency is vital. The sensor networks consist of sensor nodes that operate on battery power, and replacement of these batteries is very often a strenuous task, since networks are deployed in areas where the act of replacing the batteries proves impractical.

With the limited available energy of sensor nodes, most of the energy is drained during communication. An energy efficient routing algorithm can prolong the lifetime of the network by gradually depleting the nodes in the network. Many of the routing protocols …

Searching Blogs And News: A Study On Popular Queries, Aixin Sun, Meishan Hu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Blog/news search engines are very important channels to reach information about the real-time happenings. In this paper, we study the popular queries collected over one year period and compare their search results returned by a blog search engine (i.e., Technorati) and a news search engine (i.e., Google News). We observed that the numbers of hits returned by the two search engines for the same set of queries were highly correlated, suggesting that blogs often provide commentary to current events reported in news. As many popular queries are related to some events, we further observed a high cohesiveness among the returned …

Integrating Preservation Functions Into The Web Server, Joan A. Smith

Computer Science Theses & Dissertations

Digital preservation of theWorldWideWeb poses unique challenges, different fromthe preservation issues facing professional Digital Libraries. The complete list of a website’s resources cannot be cited with confidence, and the descriptive metadata available for the resources is so minimal that it is sometimes insufficient for a browser to recognize. In short, the Web suffers from a counting problem and a representation problem. Refreshing the bits, migrating from an obsolete file format to a newer format, and other classic digital preservation problems also affect the Web. As digital collections devise solutions to these problems, the Web will also benefit. But the core …

An Analysis Of Botnet Vulnerabilities, Sean W. Hudson

Theses and Dissertations

Botnets are a significant threat to computer networks and data stored on networked computers. The ability to inhibit communication between servers controlling the botnet and individual hosts would be an effective countermeasure. The objective of this research was to find vulnerabilities in Unreal IRCd that could be used to shut down the server. Analysis revealed that Unreal IRCd is a very mature and stable IRC server and no significant vulnerabilities were found. While this research does not eliminate the possibility that a critical vulnerability is present in the Unreal IRCd software, none were identified during this effort.

A Survey Of Satellite Communications System Vulnerabilities, Jessica A. Steinberger

Theses and Dissertations

The U.S. military’s increasing reliance on commercial and military communications satellites to enable widely-dispersed, mobile forces to communicate makes these space assets increasingly vulnerable to attack by adversaries. Attacks on these satellites could cause military communications to become unavailable at critical moments during a conflict. This research dissected a typical satellite communications system in order to provide an understanding of the possible attacker entry points into the system, to determine the vulnerabilities associated with each of these access points, and to analyze the possible impacts of these vulnerabilities to U.S. military operations. By understanding these vulnerabilities of U.S. communications satellite …

A Simulation Study Of Medium Access Control Protocols Of Wireless Networks, Rohan Uddhav Patel

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Rohan Uddhav Patel on May 8, 2008.

Resource Sharing Via Planed Relay For Hwn, Chong Shen, Susan Rea, Dirk Pesch

NIMBUS Articles

We present an improved version of adaptive distributed cross-layer routing algorithm (ADCR) for hybrid wireless network with dedicated relay stations () in this paper. A mobile terminal (MT) may borrow radio resources that are available thousands mile away via secure multihop RNs, where RNs are placed at pre-engineered locations in the network. In rural places such as mountain areas, an MT may also communicate with the core network, when intermediate MTs act as relay node with mobility. To address cross-layer network layers routing issues, the cascaded ADCR establishes routing paths across MTs, RNs, and cellular base stations (BSs) and provides …

Evaluation Of The Applicability Of Jc3iedm Based Information Exchange Standardization Efforts To Link-16 Based Systems, Anthony Devivi

Computational Modeling & Simulation Engineering Theses & Dissertations

Command and Control (C2) systems are critical components in decision-making systems in both the military and civilian domains. These systems act as the data evaluation and dissemination tools for larger Command, Control, Computer, Communication, Intelligence, Surveillance, and Recognizance (C4ISR) systems. Typical C2 systems accept a wide variety of inputs from many sources such as radars, weapons systems, simulators, operators, and other C2 systems. The C2 system processes the input data and presents to the user information with which decisions are made. The C2 system also determines what information should be translated and disseminated to other C2 platforms.

The basis for …

Composable Distributed Access Control And Integrity Policies For Query-Based Wireless Sensor Networks, David W. Marsh

Theses and Dissertations

An expected requirement of wireless sensor networks (WSN) is the support of a vast number of users while permitting limited access privileges. While WSN nodes have severe resource constraints, WSNs will need to restrict access to data, enforcing security policies to protect data within WSNs. To date, WSN security has largely been based on encryption and authentication schemes. WSN Authorization Specification Language (WASL) is specified and implemented using tools coded in JavaTM. WASL is a mechanism{independent policy language that can specify arbitrary, composable security policies. The construction, hybridization, and composition of well{known security models is demonstrated and shown to preserve …

Dialable Cryptography For Wireless Networks, Marnita T. Eaddie

Theses and Dissertations

The objective of this research is to develop an adaptive cryptographic protocol, which allows users to select an optimal cryptographic strength and algorithm based upon the hardware and bandwidth available and allows users to reason about the level of security versus the system throughput. In this constantly technically-improving society, the ability to communicate via wireless technology provides an avenue for delivering information at anytime nearly anywhere. Sensitive or classified information can be transferred wirelessly across unsecured channels by using cryptographic algorithms. The research presented will focus on dynamically selecting optimal cryptographic algorithms and cryptographic strengths based upon the hardware and …

Constellation Design Of Geosynchronous Navigation Satellites Which Maximizes Availability And Accuracy Over A Specified Region Of The Earth, Halil Ibrahim Ozdemir

Theses and Dissertations

Currently, there are four Global Navigation Satellite Systems (GNSS) either being developed or in existence-GPS, GLONASS, Compass, and Galileo. Additionally, there are several Regional Navigation Satellite Systems (RNSS) planned or in existence, as well as numerous augmentation systems (which require a GNSS for operation). It can be anticipated that there will be interest in developing additional independent regional navigation satellite systems to cover areas of interest to particular countries or regions, who want to have their own system. In this paper, a genetic algorithm is used in an effort to determine near-optimal RNSS constellations. First, a cost function is setup, …

Evaluating Security And Quality Of Service Considerations In Critical Infrastructure Communication Networks, Gregory R. Roberts

Theses and Dissertations

This thesis demonstrates the benefits of utility communication based on Internet technology, some dangers in using Internet technology in establishing a utility intranet connecting protection and control systems, and compares three different approaches to making reservations for routing traffic in the utility intranet based on different levels of background traffic. A model of expected background traffic on a national utility intranet is presented. The Utility Communication Architecture 2.0 and the International Electrotechnical Commission (IEC) 61850 began laying the groundwork in 2002 in establishing an infrastructure allowing power substations, program logic controllers, remote terminal units, intelligent electronic devices, and other devices …

Hot Swapping Protocol Implementations In The Opnet Modeler Development Environment, Mark E. Coyne

Theses and Dissertations

This research effort demonstrates hot swapping protocol implementations in OPNET via the building of a dependency injection testing framework. The thesis demonstrates the externalization (compiling as stand-alone code) of OPNET process models, and their inclusion into custom DLL's (Dynamically Linked Libraries). A framework then utilizes these process model DLL's, to specify, or “inject,” process implementations post-compile time into an OPNET simulation. Two separate applications demonstrate this mechanism. The first application is a toolkit that allows for the testing of multiple routing related protocols in various combinations without code re-compilation or scenario re-generation. The toolkit produced similar results as the same …

Network Visualization Design Using Prefuse Visualization Framework, John Mark Belue

Theses and Dissertations

Visualization of network simulation events or network visualization is an effective and low cost method to evaluate the health and status of a network and analyze network designs, protocols, and network algorithms. This research designed and developed a network event visualization framework using an open source general visualization toolkit. This research achieved three major milestones during the development of this framework: A robust network simulator trace file parser, multiple network visualization layouts {including user-defined layouts, and precise visualization timing controls and integrated display of network statistics. The parser architecture is extensible to allow customization of simulator trace formats that are …

Scripted Mobile Network Routing In A Contested Environment, Anthony R. Otto

Theses and Dissertations

Mobile wireless network protocols currently run on optimistic routing algorithms, adjusting node connectivity only when the chosen connectivity metrics, such as signal strength, pass beyond minimum thresholds. Optimistic routing has several weaknesses. Optimistic routing suffers from increased network overhead during increased frequency of node movement and increased node density per area, and optimistic routing also suffers from non-optimistic access change for individual nodes. The overall communication throughput of a network may be increased if the network topology change is scripted; a scripted plan can allow messages to travel along a more efficient topological path while creating less topology control traffic. …

Aspectization Of Web Applications Quality Of Service Measures, Lamya Atef Othman Tantawy

Archived Theses and Dissertations

No abstract provided.

Retransmission Strategies For Moving Networks Over Ricean Fading Channels, Alex Ruiz Lee

Theses

The problem of designing retransmission protocols based on Hybrid Automatic Repeat reQuest (HARQ) for moving networks over Ricean fading channels has been considered. The scenario of interest consists of one receiver traveling at a given speed while connected to a wireless network based on OFDM (e.g., WiMax) through several base stations located along the path. Five different retransmission protocols that combine HARQ with handover between adjacent base stations are considered. Their performance in terms of number of retransmissions per packet via numerical simulations, considering both frequency selective and nonselective channels are presented. The results obtained show the relevant advantage that …

Proactive Methods For Measurement Of Available Bandwidth And Link Capacity, Khondaker Musfakus Salehin

Theses

With the continuous expansion of network infrastructure and deployment of applications sensitive to Quality-of-Service, network measurement plays a major role in both network planning and management. Accurate measurement of various network parameters, e.g., available bandwidth, link capacity, delay, packet loss and jitter, provides a positive impact for effective traffic engineering, Quality-of-Service (QoS) routing, optimization of end-to-end transport performance, and link capacity planning. For network measurement, there exists several proactive estimation tools based on either probe-gap model or probe-rate model that estimate path related attributes. Most of these tools that have been implemented can measure tight-link capacity (smallest available bandwidth) and/or …