Computer Sciences Commons^™

Network Architectures For Live Peer-To-Peer Media Streaming, Jagannath Ghoshal, Lisong Xu, Byrav Ramamurthy, Miao Wang

School of Computing: Technical Reports

Peer-to-Peer (P2P) media streaming networks, motivated by the huge success of P2P file downloading networks, have recently attracted a lot of research interest. However, it is challenging to design P2P media streaming networks because of the stringent time constraints on the delivered media streams, which require more efficient and resilient overlay architectures. In this paper, we focus on live P2P media streaming networks, a promising application flourishing in the Internet and which requires the distribution of live (not stored) multimedia content to subscribers. We review the architectures for live P2P media streaming networks, and consider both overlay topologies and their …

Layered Clustering Communication Protocol For Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

In this paper, we propose a Layered Clustering Hierarchy (LCH) communication protocol for Wireless Sensor Networks (WSNs). The design of LCH has two goals: scalability and energy-efficiency. In LCH, the sensor nodes are organized as a layered clustering structure. Each layer runs a distributed clustering protocol. By randomizing the rotation of cluster heads in each layer, the energy load is distributed evenly across sensors in the network. Our simulations show that LCH is effective in densely deployed sensor networks. On average, 70% of live sensor nodes are involved directly in the clustering communication hierarchy. Moreover, the simulations also show that …

Keyrev: An Efficient Key Revocation Scheme For Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy, Xukai Zou

School of Computing: Conference and Workshop Papers

Key management is a core mechanism to ensure the security of applications and network services in wireless sensor networks. It includes two aspects: key distribution and key revocation. Key distribution has been extensively studied in the context of sensor networks. However, key revocation has received relatively little attention. Existing key revocation schemes can be divided into two categories: centralized key revocation scheme and distributed key revocation scheme. In this paper, we first summarize the current key revocation schemes for sensor networks. Then, we propose an efficient centralized key revocation scheme, KeyRev, for wireless sensor networks. Unlike most proposed key revocation …

Group Rekeying Schemes For Secure Group Communication In Wireless Sensor Networks, Yong Wang, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Wireless sensor networks are promising solutions for many applications. However, wireless sensor nodes suffer from many constraints such as low computation capability, small memory, limited energy resources, and so on. Grouping is an important technique to localize computation and reduce communication overhead in wireless sensor networks. In this paper, we use grouping to refer to the process of combining a set of sensor nodes with similar properties. We propose two centralized group rekeying (CGK) schemes for secure group communication in sensor networks. The lifetime of a group is divided into three phases, i.e., group formation, group maintenance, and group dissolution. …

A-Mac: Adaptive Medium Access Control For Next Generation Wireless Terminals, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Faculty Publications

Next Generation (NG) wireless networks are envisioned to provide high bandwidth to mobile users via bandwidth aggregation over heterogeneous wireless architectures. NG wireless networks, however, impose challenges due to their architectural heterogeneity in terms of different access schemes, resource allocation techniques as well as diverse quality of service requirements. These heterogeneities must be captured and handled dynamically as mobile terminals roam between different wireless architectures. However, to address these challenges, the existing proposals require either a significant modification in the network structure and in base stations or a completely new architecture, which lead to integration problems in terms of implementation …

A Method For Estimating Fractal Dimension Of Tree Crowns From Digital Images, Dongsheng Zhang, Ashok Samal, James R. Brandle

School of Computing: Faculty Publications

A new method for estimating fractal dimension of tree crowns from digital images is presented. Three species of trees, Japanese yew (Taxus cuspidata Sieb & Zucc), Hicks yew (Taxus × media), and eastern white pine (Pinus strobus L.), were studied. Fractal dimensions of Japanese yew and Hicks yew range from 2.26 to 2.70. Fractal dimension of eastern white pine range from 2.14 to 2.43. The difference in fractal dimension between Japanese yew and eastern white pine was statistically significant at 0.05 significance level as was the difference in fractal dimension between Hicks yew and eastern white …

Bandit-Based Algorithms For Budgeted Learning, Kun Deng, Chris Bourke, Stephen Scott, Julie Sunderman, Yaling Zheng

School of Computing: Conference and Workshop Papers

We explore the problem of budgeted machine learning, in which the learning algorithm has free access to the training examples’ labels but has to pay for each attribute that is specified. This learning model is appropriate in many areas, including medical applications. We present new algorithms for choosing which attributes to purchase of which examples in the budgeted learning model based on algorithms for the multi-armed bandit problem. All of our approaches outperformed the current state of the art. Furthermore, we present a new means for selecting an example to purchase after the attribute is selected, instead of selecting an …

An Interactive Constraint-Based Approach To Sudoku, Christopher G. Reeson, Kai-Chen Huang, Ken Bayer, Berthe Y. Choueiry

School of Computing: Conference and Workshop Papers

We present SOLVER, a Java applet that uses Constraint Processing (CP) techniques to assist human users in solving Sudoku puzzles. We also showcase CONSTRUCTOR, another applet that allows users to enter and store puzzles, which they can then load in SOLVER. These applets are available from sudoku.unl.edu/Solver and sudoku. unl.edu/Constructor. Our goals are as follows:

• To the public: Illustrate the power of CP techniques in the context of a popular easily approachable puzzle.

• For the research: Investigate how to use CP to interactively support and guide human players.

• For education: Use the Sudoku puzzle as a means …

Efficient Rtl Coverage Metric For Functional Test Selection, Jian Kang, Sharad C. Seth, Vijay Gangaram

School of Computing: Conference and Workshop Papers

For performance-critical microprocessors, efficient test-selection methods are needed for reusing a subset of functional validation tests to detect manufacturing defects. Our new input/output transition fault-coverage metric (TRIO) at the register-transfer level is shown to perform much better than current metric in test selection at only an incrementally higher computational cost. TRIO may also be used for testability analysis early in the design cycle.

Symbolic Path Sensitization Analysis And Applications, Jian Kang, Sharad C. Seth, Shashank K. Mehta

School of Computing: Conference and Workshop Papers

A new symbolic approach models the sensitization paths to selected primary output(s) as Boolean equations, with satisfying solutions representing the set of all sources of single and multiple sensitizations in the circuit. The paper discusses two applications of this idea: model-free fault diagnosis and input sensitization analysis.

A Note On The Karp-Lipton Collapse For The Exponential Hierarchy, Chris Bourke

School of Computing: Technical Reports

We extend previous collapsing results involving the exponential hierarchy by using recent hardness-randomness trade-off results. Specifically, we show that if the second level of the exponential hierarchy has polynomial-sized circuits, then it collapses all the way down to MA.

A Theory And Practice Of Website Engagibility, Ronan Fitzpatrick

Doctoral

This thesis explores the domain of website quality. It presents a new study of website quality - an abstraction and synthesis, a measurement methodology, and analysis - and proposes metrics which can be used to quantify it. The strategy employed involved revisiting software quality, modelling its broader perspectives and identifying quality factors which are specific to the World Wide Web (WWW). This resulted in a detailed set of elements which constitute website quality, a method for quantifying a quality measure, and demonstrating an approach to benchmarking eCommerce websites. The thesis has two dimensions. The first is a contribution to the …

Businessfinder: Harnessing Presence To Enable Live Yellow Pages For Small, Medium And Micro Mobile Businesses, D. Chakraborty, K. Dasgupta, S. Mittal, Archan Misra, C. Oberle, A. Gupta, E. Newmark

Research Collection School Of Computing and Information Systems

Applications leveraging network presence in next-generation cellular networks have so far focused on subscription queries, where "presence" information is extracted from specific devices and sent to entities who have subscribed to such presence information. In this article we present BusinessFinder, a service that leverages the underlying cellular presence substrate to provide efficient, on-demand, context-aware matching of customer requests to nomadic micro businesses as well as small and medium businesses having a mobile workforce. Presence, in the context of BusinessFinder, is not simply limited to phone location and device status, but also encompasses dynamic attributes of vendors (both "mobile" and "static"), …

The Systemic Nature Of Critical Infrastructure Protection Using A Medium Sized Company As The Case Study, Jeffery Sewell

Theses : Honours

Critical infrastructure can be defined as privately and publicly run organisations such as energy systems, water systems, transportation, telecommunications, emergency services, banking and finance. The critical infrastructure (CI) on which society relies is now dependent on the interconnected communication networks the information age has spawned. With the evolution of the information age, not only has the communications landscape changed dramatically, the security landscape has changed too. With information technology being so ubiquitous, it has created new underlying concerns about the systems now reliant on them. The reliance and complexity of these interconnected systems has increased vulnerabilities confronting critical infrastructure. This …

Pov-It: The Pov-Ray Interactive Tutorial, Eleanor O'Rourke

Honors Theses

The Persistence of Vision Ray Tracer, commonly known as POV-Ray, is a computer graphics package that can be used to produce highly sophisticated and photorealistic images and animations. POV-Ray is widely used in the computer graphics community for a diverse variety of applications, including teaching college courses, creating visual music animations, and generating computer art. Although the popularity of POV-Ray is apparent, the teaching materials available for the package are confusing, disorganized, and inaccessible. In this project, I have designed an online system that provides a series of interactive tutorials that teach users how to create images using the POV-Ray …

Towards A Self-Calibrating Video Camera Network For Content Analysis And Forensics, Imran Junejo

Electronic Theses and Dissertations

Due to growing security concerns, video surveillance and monitoring has received an immense attention from both federal agencies and private firms. The main concern is that a single camera, even if allowed to rotate or translate, is not sufficient to cover a large area for video surveillance. A more general solution with wide range of applications is to allow the deployed cameras to have a non-overlapping field of view (FoV) and to, if possible, allow these cameras to move freely in 3D space. This thesis addresses the issue of how cameras in such a network can be calibrated and how …

Learning, Detection, Representation, Indexing And Retrieval Of Multi-Agent Events In Videos, Asaad Hakeem

Electronic Theses and Dissertations

The world that we live in is a complex network of agents and their interactions which are termed as events. An instance of an event is composed of directly measurable low-level actions (which I term sub-events) having a temporal order. Also, the agents can act independently (e.g. voting) as well as collectively (e.g. scoring a touch-down in a football game) to perform an event. With the dawn of the new millennium, the low-level vision tasks such as segmentation, object classification, and tracking have become fairly robust. But a representational gap still exists between low-level measurements and high-level understanding of video …

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

Separations Campaign (TRP)

The major objectives will lead to a creation of framework that combines all the strengths of AMUSE’s complicated calculations, well-established commercial system process package and ISOPro’s flexible parameter optimization modules. Development of the process simulation code can be done using the solvent extraction process at Argonne National Laboratory in collaboration with the research team from Mechanical Engineering Department at UNLV.

Research accomplishments:

• Integrated the ASPEN-Plus process model with the ISOPro system engineering modeling package, developed by the UNLV team.
• Tested the simplified system process integration using the ISOPro package.
• Generated complete version of the ISOPro package user manual and tutorial. …

An Environmental Complexity Analysis For Robot-Environment System Design, Gang Yang

Theses and Dissertations

Recently, researchers have begun to investigate intelligent environments for robot applications. In this work, a robot and its work environment can be considered to be an integrated system. Currently, such robot-environment systems are designed on an ad-hoc basis, with the final performance of the system greatly dependent on the experience and preferences of the designer. This dissertation investigates a way to improve on this situation by looking at the complexity of an environment from the perspective of a robot. The objective of this research is to develop a method to evaluate environmental complexity and then use this information to help …

Mining Frequent Patterns From Sequences: Theory, Algorithm, Implementation, And Performance, Markus Petteri Turkia

Theses and Dissertations

Mining frequent patterns from sequences is an important data mining problem which has direct applications in many areas. In this thesis, we make three contributions to the state-of-the-art of the sequential frequent pattern mining. First of all, we propose a fast pattern-growth mining algorithm using a novel sequence database representation called First-Occurrence Linked WAP-tree (FLWAP-tree). The pattern-growth mining algorithm using the Pre-Order Linked WAP-tree (PLWAP-tree) was reported in the literature to be faster than other algorithms. We show that our pattern-growth using our FLWAP-tree outperforms the PLWAP-tree mining significantly and consistently. Secondly, we extend the pattern-growth algorithm with partial enumeration …

Workshop Report — Crawdad Workshop 2006, Jihwang Yeo, Tristan Henderson, David Kotz

Dartmouth Scholarship

Wireless network researchers are seriously starved for data about how real users, applications, and devices use real networks under real network conditions. CRAWDAD, the Community Resource for Archiving Wireless Data at Dartmouth, is an NSF-funded project that is building a wireless network data archive for the research community. We host wireless data, and provide tools and documents to make it easy to collect and use wireless network data. We hope that this resource will help researchers to identify and evaluate real and interesting problems in mobile and pervasive computing. This report outlines the CRAWDAD project and summarizes the second CRAWDAD …

Physically-Based Visualization Of Residential Building Damage Process In Hurricane, Dezhi Liao

Electronic Theses and Dissertations

This research provides realistic techniques to visualize the process of damage to residential building caused by hurricane force winds. Three methods are implemented to make the visualization useful for educating the public about mitigation measures for their homes. First, the underline physics uses Quick Collision Response Calculation. This is an iterative method, which can tune the accuracy and the performance to calculate collision response between building components. Secondly, the damage process is designed as a Time-scalable Process. By attaching a damage time tag for each building component, the visualization process is treated as a geometry animation allowing users to navigate …

Real-Time Tree Simulation Using Verlet Integration, Bobak Manavi

Electronic Theses and Dissertations

One of the most important challenges in real-time simulation of large trees and vegetation is the vast number of calculations required to simulate the interactions between all the branches in the tree when external forces are applied to it. This paper will propose the use of algorithms employed by applications like cloth and soft body simulations, where objects can be represented by a finite system of particles connected via spring-like constraints, for the structural representation and manipulation of trees in real-time. We will then derive and show the use of Verlet integration and the constraint configuration used for simulating trees …

Gigabit Concept Mining: A Sensitivity Analysis, Masters Thesis, December 2006, Andrew Levine

All Computer Science and Engineering Research

Massive amounts of data are passed over public networks. There is a need for network administrators to analyze this traffic, but it was not previously possible to analyze live network data at high speed. It has been shown that streaming computation and deep packet analysis are possible at very high rates through the use of hardware acceleration. This work provides analysis for a larger project that involves digesting large amounts of network traffic. In this system, we process the traffic using hardware that has constraints. The workings of the system are first discussed. Tradeoffs in the design of hardware and …

Leveraging Est Evidence To Automatically Predict Alternatively Spliced Genes, Master's Thesis, December 2006, Robert Zimmermann

All Computer Science and Engineering Research

Current methods for high-throughput automatic annotation of newly sequenced genomes are largely limited to tools which predict only one transcript per gene locus. Evidence suggests that 20-50% of genes in higher eukariotic organisms are alternatively spliced. This leaves the remainder of the transcripts to be annotated by hand, an expensive time-consuming process. Genomes are being sequenced at a much higher rate than they can be annotated. We present three methods for using the alignments of inexpensive Expressed Sequence Tags in combination with HMM-based gene prediction with N-SCAN EST to recreate the vast majority of hand annotations in the D.melanogaster genome. …

The Effect Of Object Color On Depth Ordering, Reynold Bailey, Cindy Grimm, Christopher Davoli, Richard Abrams

All Computer Science and Engineering Research

The relationship between color and perceived depth for realistic, colored objects with varying shading was explored. Background: Studies have shown that warm-colored stimuli tend to appear nearer in depth than cool-colored stimuli. The majority of these studies asked human observers to view physically equidistant, colored stimuli and compare them for relative depth. However, in most cases, the stimuli presented were rather simple: straight colored lines, uniform color patches, point light sources, or symmetrical objects with uniform shading. Additionally, the colors were typically highly saturated. Although such stimuli are useful for isolating and studying depth cues in certain contexts, they leave …

Control Of A Robotic Arm Using Low-Dimensional Emg And Ecog Biofeedback, Timothy M. Blackely, William D. Smart

All Computer Science and Engineering Research

In this dissertation we describe a system that uses a low dimensional input derived from electromyography and electrocorticography data to control a robot. The work involves creating a system that allows signals recorded directly from a human body to allow control of a small robot arm. We compare direct joystick control with electromyogram (EMG) input to determine if one input system is superior, or if the quality of control between them is comparable. We also verify the system that is used to record the electromyogram signals is adaptable to other forms of biosignal input; in particular, direct connection to a …

Splice: A Standardized Peripheral Logic And Interface Creation Engine, Master's Thesis, May 2007, Justin Thiel

All Computer Science and Engineering Research

Recent advancements in FPGA technology have allowed manufacturers to place general-purpose processors alongside user-configurable logic gates on a single chip. At first glance, these integrated devices would seem to be the ideal deployment platform for hardware-software co-designed systems, but some issues, such as incompatibility across vendors and confusion over which bus interfaces to support, have impeded adoption of these platforms. This thesis describes the design and operation of Splice, a software-based code generation tool intended to address these types of issues by providing a bus-independent structure that allows end-users to easily integrate their customized peripheral logic into embedded systems. To …

Experimental Evaluation Of A Coarse-Grained Switch Scheduler, Charlie Wiseman, Jon Turner, Ken Wong, Brandon Heller

All Computer Science and Engineering Research

Modern high performance routers rely on sophisticated interconnection networks to meet ever increasing demands on capacity. Regulating the flow of packets through these interconnects is critical to providing good performance, particularly in the presence of extreme traffic patterns that result in sustained overload at output ports. Previous studies have used a combination of analysis and idealized simulations to show that coarse-grained scheduling of traffic flows can be effective in preventing congestion, while ensuring high utilization. In this paper, we study the performance of a coarse-grained scheduler in a real router with a scalable architecture similar to those found in high …

Image Segmentation Using Multi-Coloured Active Illumination, Tze Ki (Xu Shuqi) Koh, Nicholas Miles, Barrie Hayes-Gill

Research Collection School Of Computing and Information Systems

In this paper, the use of active illumination is extended to image segmentation, specifically in the case of overlapping particles. This work is based on Multi-Flash Imaging (MFI), originally developed by Mitsubishi Electric Labs, to detect depth discontinuities. Illuminations of different wavelengths are projected from multiple positions, providing additional information about a scene compared to conventional segmentation techniques. Shadows are used to identify true object edges. The identification of non- occluded particles is made possible by exploiting the fact that shadows are cast on underlying particles. Implementation issues such as selecting the appropriate colour model and number of illuminations are …