Digital Commons Network^™

Real-Time Realistic Rendering And High Dynamic Range Image Display And Compression, Ruifeng Xu

Electronic Theses and Dissertations

This dissertation focuses on the many issues that arise from the visual rendering problem. Of primary consideration is light transport simulation, which is known to be computationally expensive. Monte Carlo methods represent a simple and general class of algorithms often used for light transport computation. Unfortunately, the images resulting from Monte Carlo approaches generally suffer from visually unacceptable noise artifacts. The result of any light transport simulation is, by its very nature, an image of high dynamic range (HDR). This leads to the issues of the display of such images on conventional low dynamic range devices and the development of …

Scene Monitoring With A Forest Of Cooperative Sensors, Omar Javed

Electronic Theses and Dissertations

In this dissertation, we present vision based scene interpretation methods for monitoring of people and vehicles, in real-time, within a busy environment using a forest of co-operative electro-optical (EO) sensors. We have developed novel video understanding algorithms with learning capability, to detect and categorize people and vehicles, track them with in a camera and hand-off this information across multiple networked cameras for multi-camera tracking. The ability to learn prevents the need for extensive manual intervention, site models and camera calibration, and provides adaptability to changing environmental conditions. For object detection and categorization in the video stream, a two step detection …

Enhancing Message Privacy In Wired Equivalent Privacy., Darshan Purandare

Electronic Theses and Dissertations

The 802.11 standard defines the Wired Equivalent Privacy (WEP) and encapsulation of data frames. It is intended to provide data privacy to the level of a wired network. WEP suffered threat of attacks from hackers owing to certain security shortcomings in the WEP protocol. Lately, many new protocols like WiFi Protected Access (WPA), WPA2, Robust Secure Network (RSN) and 802.11i have come into being, yet their implementation is fairly limited. Despite its shortcomings one cannot undermine the importance of WEP as it still remains the most widely used system and we chose to address certain security issues and propose some …

Qos In Cognitive Packet Networks: Adaptive Routing, Flow And Congestion Control, Pu Su

Electronic Theses and Dissertations

With the emergence of various applications that have different Quality of Service (QoS) requirements, the capability of a network to support QoS becomes more and more important and necessary. This dissertation explores QoS in Cognitive Packet Networks (CPN) by using adaptive routing, flow and congestion control. We present a detailed description and analysis of our proposed routing algorithms based on single and multiple QoS constraints. An online estimation of packet loss rate over a path is introduced. We implement and evaluate the adaptive routing scheme in an experimental CPN test-bed. Our experiments support our claims that the users can achieve …

Access Games: A Game Theoretic Framework For Fair Bandwidth Sharing In Distributed Systems, Sudipta Rakshit

Electronic Theses and Dissertations

In this dissertation, the central objective is to achieve fairness in bandwidth sharing amongst selfish users in a distributed system. Because of the inherent contention-based nature of the distributed medium access and the selfishness of the users, the distributed medium access is modeled as a non-cooperative game; designated as the Access Game. A p-CSMA type medium access scenario is proposed for all the users. Therefore, in the Access Game, each user has two actions to choose from: "transmit" and "wait". The outcome of the Access Game and payoffs to each user depends on the actions taken by all the users. …

Resource Allocation Schemes And Performance Evaluation Models For Wavelength Division Multiplexed Optical Networks, Mounire El Houmaidi

Electronic Theses and Dissertations

Wavelength division multiplexed (WDM) optical networks are rapidly becoming the technology of choice in network infrastructure and next-generation Internet architectures. WDM networks have the potential to provide unprecedented bandwidth, reduce processing cost, achieve protocol transparency, and enable efficient failure handling. This dissertation addresses the important issues of improving the performance and enhancing the reliability of WDM networks as well as modeling and evaluating the performance of these networks. Optical wavelength conversion is one of the emerging WDM enabling technologies that can significantly improve bandwidth utilization in optical networks. A new approach for the sparse placement of full wavelength converters based …

Predicting Software Size And Development Effort: Models Based On Stepwise Refinement, David P. Voorhees

CCAC Theses and Dissertations

This study designed a Software Size Model and an Effort Prediction Model, then performed an empirical analysis of these two models. Each model design began with identifying its objectives, which led to describing the concept to be measured and the meta-model. The numerical assignment rules were then developed, providing a basis for size measurement and effort prediction across software engineering projects. The Software Size Model was designed to test the hypothesis that a software size measure represents the amount of knowledge acquired and stored in software artifacts, and the amount of time it took to acquire and store this knowledge. …

Prioritization Methods For Accelerating Mdp Solvers, Kevin Seppi, David Wingate

Faculty Publications

The performance of value and policy iteration can be dramatically improved by eliminating redundant or useless backups, and by backing up states in the right order. We study several methods designed to accelerate these iterative solvers, including prioritization, partitioning, and variable reordering. We generate a family of algorithms by combining several of the methods discussed, and present extensive empirical evidence demonstrating that performance can improve by several orders of magnitude for many problems, while preserving accuracy and convergence guarantees.

Autonomous Vehicle Technologies For Small Fixed-Wing Uavs, Randal Beard, Derek Kingston, Morgan Quigley, Deryl Snyder, Reed Christiansen, Walt Johnson, Timothy Mclain, Michael A. Goodrich

Faculty Publications

The objective of this paper is to describe the design and implementation of a small semi-autonomous fixed-wing unmanned air vehicle. In particular we describe the hardware and software architectures used in the design. We also describe a low weight, low cost autopilot developed at Brigham Young University and the algorithms associated with the autopilot. Novel PDA and voice interfaces to the UAV are described. In addition, we overview our approach to real-time path planning, trajectory generation, and trajectory tracking. The paper is augmented with movie files that demonstrate the functionality of the UAV and its control software.

Numerical Modelling Of Sediments In Cork Harbour, Jérémy Pingon

Theses

In recent years there have been considerable developments in the new and emerging field of hydroinformatics. This relatively new discipline is concerned with the application of computer and networking technology for the planning, management and protection of water bodies.

Environmental issues in estuaries require accurate and detailed knowledge of cohesive sediment transport processes to assess different issues including water quality, pollutant dispersion, and dredging and maintenance of navigation channels.

This thesis presents a review of the main sediment properties and processes required for modelling the behaviour and transport of sediments. It also introduces a new approach to sediment properties using …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 4, January 2005, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Sean Hsieh

Separations Campaign (TRP)

The chemical processing of used nuclear fuel is an integral component of any strategy for the transmutation of nuclear waste. Due to the large volume of material that must be handled in this first step of the transmutation process, the efficiency of the separations process is a key factor in the potential economic viability of transmutation strategies. The ability to optimize the chemical separation systems is vital to ensure the feasibility of the transmutation program.

Systems analysis, or total systems modeling, is one of the strongest tools available to researchers for understanding and optimizing complex systems such as chemical separations …

Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The major objective is to create a framework that combines all the strengths of AMUSE’s complicated calculations, well established commercial system process package such as ASPENPLUS, HYSYS and PRO/II and TRPSEMPro’s flexible parameter optimization modules. Development of the process simulation code can be done using the solvent extraction process experience at Argonne National Laboratory and in collaboration with the NCACM.

The major activities of the task are the following:

• Develop a framework for simulating the SFTF process using AMUSE code, commercial process package, such as ASPEN- PLUS, and system engineering model.
• Develop a middleware package that can communicate between the …

A Generative Programming Approach To Interactive Information Retrieval: Insights And Experiences, Saverio Perugini, Naren Ramakrishnan

Computer Science Faculty Publications

We describe the application of generative programming to a problem in interactive information retrieval. The particular interactive information retrieval problem we study is the support for "out-of-turn interaction" with a website – how a user can communicate input to a website when the site is not soliciting such information on the current page, but will do so on a subsequent page. Our solution approach makes generous use of program transformations (partial evaluation, currying, and slicing) to delay the site’s current solicitation for input until after the user’s out-of-turn input is processed. We illustrate how studying out-of-turn interaction through a generative …

Establishing An Online Community Of Practice For Instructors Of English As A Foreign Language, Christopher M. Johnson

CCAC Theses and Dissertations

Communities of practice are entities that emerge for the purposes of learning and advancement of knowledge in a particular area. They emerge under all circumstances, even adverse situations. Because they can spawn great innovation and knowledge advancement, organizations need to cultivate and establish environments that allow them to develop. Currently, communities of practice have moved into the online world, in which their members use computer mediated communication to collaborate with each other.

In January, 2002, a virtual community was formed to enable teachers of English as a Foreign Language to collaborate on learning and applying various computing technologies in language …

Linear Correlation Discovery In Databases: A Data Mining Approach, Cecil Chua, Roger Hsiang-Li Chiang, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Very little research in knowledge discovery has studied how to incorporate statistical methods to automate linear correlation discovery (LCD). We present an automatic LCD methodology that adopts statistical measurement functions to discover correlations from databases’ attributes. Our methodology automatically pairs attribute groups having potential linear correlations, measures the linear correlation of each pair of attribute groups, and confirms the discovered correlation. The methodology is evaluated in two sets of experiments. The results demonstrate the methodology’s ability to facilitate linear correlation discovery for databases with a large amount of data.

Special Section: Human-Computer Interaction Research In Management Information Systems, Ping Zhang, Fiona Fui-Hoon Nah, Izak Benbasat

Research Collection School Of Computing and Information Systems

No abstract provided.

Global Multimedia Collaboration System, Geoffrey C. Fox, Wenjun Wu, Ahmet Uyar, Hasan Bulut, Shrideep Pallickard

Electrical Engineering and Computer Science - All Scholarship

In order to build an integrated collaboration system over heterogeneous collaboration technologies, we propose a Global Multimedia Collaboration System (Global-MMCS) based on XGSP A/V Web-Services framework. This system can integrate multiple A/V services, and support various collaboration clients and communities. Now the prototype is being developed and deployed across many universities in USA and China.

Lad: Localization Anomaly Detection For Wireless Sensor Networks, Wenliang Du, Lei Fang, Peng Ning

Electrical Engineering and Computer Science - All Scholarship

In wireless sensor networks (WSNs), sensors ’ locations play a critical role in many applications. Having a GPS receiver on every sensor node is costly. In the past, a number of location discovery (localization) schemes have been proposed. Most of these schemes share a common feature: they use some special nodes, called beacon nodes, which are assumed to know their own locations (e.g., through GPS receivers or manual configuration). Other sensors discover their locations based on the reference information provided by these beacon nodes. Most of the beacon-based localization schemes assume a benign environment, where all beacon nodes are supposed …

A State-Free Data Delivery Protocol For Multihop Wireless Sensor Networks, Dazhi Chen, Jing Deng, Pramod K. Varshney

Electrical Engineering and Computer Science - All Scholarship

A novel, state-free, and competition-based data delivery protocol, called State-free Implicit Forwarding (SIF), is proposed for multihop wireless sensor networks. The SIF protocol assumes moderate node density and distance-to-sink awareness. The state-free feature of SIF makes it robust to high network dynamics. SIF also combines the tasks of routing and MAC, via cross-layer design, to simplify the complexity of the protocol stack in sensors and to save precious network resources. Simulation results are presented to show that SIF performs better than some previously proposed protocols for data delivery in terms of communication overhead, packet delivery ratio, and average packet delay.

Reliability-Centric High-Level Synthesis, S. Tosun, N. Mansouri, E. Arvas, Mahmut Kandemir, Yuan Xie

Electrical Engineering and Computer Science - All Scholarship

Importance of addressing soft errors in both safety critical applications and commercial consumer products is increasing, mainly due to ever shrinking geometries, higher-density circuits, and employment of power-saving techniques such as voltage scaling and component shut-down. As a result, it is becoming necessary to treat reliability as a first-class citizen in system design. In particular, reliability decisions taken early in system design can have significant benefits in terms of design quality. Motivated by this observation, this paper presents a reliability-centric high-level synthesis approach that addresses the soft error problem. The proposed approach tries to maximize reliability of the design while …

Compressed Pattern Matching For Text And Images, Tao Tao

Electronic Theses and Dissertations

The amount of information that we are dealing with today is being generated at an ever-increasing rate. On one hand, data compression is needed to efficiently store, organize the data and transport the data over the limited-bandwidth network. On the other hand, efficient information retrieval is needed to speedily find the relevant information from this huge mass of data using available resources. The compressed pattern matching problem can be stated as: given the compressed format of a text or an image and a pattern string or a pattern image, report the occurrence(s) of the pattern in the text or image …

Multi-Objective Mobile Agent Routing In Wireless Sensor Networks, Ramesh Rajagopalan, Chilukuri K. Mohan, Pramod Varshney, Kishan Mehrotra

Electrical Engineering and Computer Science - All Scholarship

A recent approach for data fusion in wireless sensor networks involves the use of mobile agents that selectively visit the sensors and incrementally fuse the data, thereby eliminating the unnecessary transmission of irrelevant or non-critical data. The order of sensors visited along the route determines the quality of the fused data and the communication cost. We model the mobile agent routing problem as a multi-objective optimization problem, maximizing the total detected signal energy while minimizing the energy consumption and path loss. Simulation results show that this problem can be solved successfully using evolutionary multi-objective algorithms such as EMOCA and NSGA-II. …

An Interactive Distributed Simulation Framework With Application To Wireless Networks And Intrusion Detection, Oleg Kachirski

Electronic Theses and Dissertations

In this dissertation, we describe the portable, open-source distributed simulation framework (WINDS) targeting simulations of wireless network infrastructures that we have developed. We present the simulation framework which uses modular architecture and apply the framework to studies of mobility pattern effects, routing and intrusion detection mechanisms in simulations of large-scale wireless ad hoc, infrastructure, and totally mobile networks. The distributed simulations within the framework execute seamlessly and transparently to the user on a symmetric multiprocessor cluster computer or a network of computers with no modifications to the code or user objects. A visual graphical interface precisely depicts simulation object states …

Creating Models Of Internet Background Traffic Suitable For Use In Evaluating Network Intrusion Detection Systems, Song Luo

Electronic Theses and Dissertations

This dissertation addresses Internet background traffic generation and network intrusion detection. It is organized in two parts. Part one introduces a method to model realistic Internet background traffic and demonstrates how the models are used both in a simulation environment and in a lab environment. Part two introduces two different NID (Network Intrusion Detection) techniques and evaluates them using the modeled background traffic. To demonstrate the approach we modeled five major application layer protocols: HTTP, FTP, SSH, SMTP and POP3. The model of each protocol includes an empirical probability distribution plus estimates of application-specific parameters. Due to the complexity of …

Analyzing The Community Structure Of Web-Like Networks: Models And Algorithms, Aurel Cami

Electronic Theses and Dissertations

This dissertation investigates the community structure of web-like networks (i.e., large, random, real-life networks such as the World Wide Web and the Internet). Recently, it has been shown that many such networks have a locally dense and globally sparse structure with certain small, dense subgraphs occurring much more frequently than they do in the classical Erdös-Rényi random graphs. This peculiarity--which is commonly referred to as community structure--has been observed in seemingly unrelated networks such as the Web, email networks, citation networks, biological networks, etc. The pervasiveness of this phenomenon has led many researchers to believe that such cohesive groups of …

Planning And Scheduling For Large-Scaledistributed Systems, Han Yu

Electronic Theses and Dissertations

Many applications require computing resources well beyond those available on any single system. Simulations of atomic and subatomic systems with application to material science, computations related to study of natural sciences, and computer-aided design are examples of applications that can benefit from the resource-rich environment provided by a large collection of autonomous systems interconnected by high-speed networks. To transform such a collection of systems into a user's virtual machine, we have to develop new algorithms for coordination, planning, scheduling, resource discovery, and other functions that can be automated. Then we can develop societal services based upon these algorithms, which hide …

Graph-Theoretic Approach To Modeling Propagation And Control Of Network Worms, Zoran Nikoloski

Electronic Theses and Dissertations

In today's network-dependent society, cyber attacks with network worms have become the predominant threat to confidentiality, integrity, and availability of network computing resources. Despite ongoing research efforts, there is still no comprehensive network-security solution aimed at controling large-scale worm propagation. The aim of this work is fivefold: (1) Developing an accurate combinatorial model of worm propagation that can facilitate the analysis of worm control strategies, (2) Building an accurate epidemiological model for the propagation of a worm employing local strategies, (3) Devising distributed architecture and algorithms for detection of worm scanning activities, (4) Designing effective control strategies against the worm, …

Contributions To Automatic Particle Identification In Electron Micrographs: Algorithms, Implementation, And Applications, Vivek Singh

Electronic Theses and Dissertations

Three dimensional reconstruction of large macromolecules like viruses at resolutions below 8 Ã… - 10 Ã… requires a large set of projection images and the particle identification step becomes a bottleneck. Several automatic and semi-automatic particle detection algorithms have been developed along the years. We present a general technique designed to automatically identify the projection images of particles. The method utilizes Markov random field modelling of the projected images and involves a preprocessing of electron micrographs followed by image segmentation and post processing for boxing of the particle projections. Due to the typically extensive computational requirements for extracting hundreds of …

Multizoom Activity Recognition Using Machine Learning, Raymond Smith

Electronic Theses and Dissertations

In this thesis we present a system for detection of events in video. First a multiview approach to automatically detect and track heads and hands in a scene is described. Then, by making use of epipolar, spatial, trajectory, and appearance constraints, objects are labeled consistently across cameras (zooms). Finally, we demonstrate a new machine learning paradigm, TemporalBoost, that can recognize events in video. One aspect of any machine learning algorithm is in the feature set used. The approach taken here is to build a large set of activity features, though TemporalBoost itself is able to work with any feature set …