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Performance Analysis Of The Beacon Period Contraction Mechanism In Wimedia Mac For Uwb, Shenjin Sun
Performance Analysis Of The Beacon Period Contraction Mechanism In Wimedia Mac For Uwb, Shenjin Sun
Computer Science and Engineering Theses
The WiMedia MAC for UWB based WPANs is currently preferred among standards for wireless network since it requires non-infrastructure for ad hoc network, and also supports for Quality of Service (QoS). Without infrastructure, coordination of devices within radio range is achieved by the exchange of beacon frames, which is an overhead in WiMedia MAC, since no data transmission is allowed during Beacon Period (BP). In a dynamic network, devices might leave or join in, so beacon slots will be released or reoccupied with the changing of network. And BP contraction mechanism is aimed at reusing the released beacon slots in …
Ca-Ole- A Collaborative And Adaptive Online Learning Environment, Paola Gomez
Ca-Ole- A Collaborative And Adaptive Online Learning Environment, Paola Gomez
Computer Science and Engineering Theses
Demand for online learning environments has grown in the past few years, and schools have been offering more distance courses to their students. Designing adequate online learning environments is considerably more challenging than conventional Face-To-Face courses; therefore traditional methods can not be used. This thesis proposes the creation of a Collaborative and Adaptive Online Learning Environment (CA-OLE) that provides a structure where instructors can combine their lesson materials with an adaptive system and collaborative tools. CA-OLE innovative approach consists of an adaptive framework that changes the way the learning materials prepared by instructors are presented to the students depending on …
Runtime Optimization And Load Shedding In Mavstream: Design And Implementation, Balakumar Kendai
Runtime Optimization And Load Shedding In Mavstream: Design And Implementation, Balakumar Kendai
Computer Science and Engineering Theses
In data stream processing systems Quality of Service (or QoS) is extremely important. The system should try its best to meet the QoS requirements specified by a user. On account of this difference, unlike in a database management system, a query cannot be optimized once and executed. It has been shown that different scheduling strategies are useful in trading tuple latency requirements with memory and throughput requirements. In addition, data stream processing systems may experience significant fluctuations in input rates. In order to meet the QoS requirements of data stream processing, a runtime optimizer equipped with several scheduling and load …
Analyzing Differences In Color Variation Sensitivity Between Experts And Novices To Find A Differentiating Process In Pigmented Skin Lesion Diagnosis, Yu-Chin Chai
Computer Science and Engineering Theses
Fatal skin lesions such as melanomas appear as having high color variation to experts but often as having low variation to novices. This thesis investigated if it is possible to find a function representing an expert's color variation sensitivity to skin lesions without explicitly requiring them to provide a diagnosis. Various pigmented skin images with either normal pigmentation or with diseased lesions were evaluated by experts and novices. To determine the best color space for lesion differentiation, an optimization process based on parametric color dimensions in a RGB color space was used to find the parameters of a color transformation …
Compensation Of Photobleached Images For A Cell Dynamics System, Sowmya Gopinath
Compensation Of Photobleached Images For A Cell Dynamics System, Sowmya Gopinath
Computer Science and Engineering Theses
Progress in the field of medicine attributes to the discoveries in biology that require an extensive knowledge of cell dynamics. Intracellular Cell Dynamics Analysis System (ICellDAS) is a web based tool aimed at automating sub cellular particle motion estimation, tracking and mobility analysis. The purpose of this tool is to develop a better understanding of specific biology problems by visualizing biological data. For reliable analysis as well as visualization of cell dynamics, it is essential that the acquired images reflect the exact information of the specimen. The goal of the thesis is to design an interface for the ICellDAS project …
Personalizing (Re-Ranking) Web Search Results Using Information Present On A Social Network, Sushruth Puttaswamy
Personalizing (Re-Ranking) Web Search Results Using Information Present On A Social Network, Sushruth Puttaswamy
Computer Science and Engineering Theses
We describe a social search engine paradigm which can be built on top of a classic search engine (e.g. Google, Yahoo, etc.) and a social information network (such as FriendSter). In this thesis, the objective was to design algorithms and develop methods to efficiently combine information available in the underlying systems (Search Engine & Social Information Network) to better satisfy the search needs of a user. We are interested on how to efficiently employ social information to re-order a list of URLs retrieved by querying a search engine. The objective was to re-order the list of URLs in a way …
Tracing And Replay Of Real-Time Concurrent Programs In Vxworks, Daxa Keshavji Patel
Tracing And Replay Of Real-Time Concurrent Programs In Vxworks, Daxa Keshavji Patel
Computer Science and Engineering Theses
Real-time concurrent programs are difficult to analyze, debug and test because of the existence of race conditions. In particular, cyclic debugging requires the ability to reproduce a failed execution. That is, when a failure is observed during a test run, it is often necessary to reproduce the test run as an effort to locate the bug that has caused the failure. However because of the variations in thread scheduling and signal latency, a real-time concurrent execution may not be reproduced simply by re-executing the program under test. In this thesis, we describe a language-based framework for tracing and replay of …
End-To-End Optimal Algorithms For Traffic Engineering, Failure Detection And Recovery In Connectionless Networks, Sukruth Srikantha
End-To-End Optimal Algorithms For Traffic Engineering, Failure Detection And Recovery In Connectionless Networks, Sukruth Srikantha
Computer Science and Engineering Theses
In this thesis we propose a novel scheme to achieve intra-domain Traffic Engineering (TE), Failure Detection and Recovery (FR) in connectionless networks. This scheme addresses rate adaptation, load balancing and stability issues of the OSPF protocol namely, network convergence times and route flapping. With the current default settings of the OSPF parameters, the network takes several tens of seconds to recover from a failure. The main component in this delay is the time required to detect the failure using the Hello protocol. Route flap is another undesirable phenomenon and needs to be eliminated to achieve greater stability and robustness in …
Adaptive Load Balancing And Change Visualization For Webvigil, Subramanian Chelladurai Hari Hara
Adaptive Load Balancing And Change Visualization For Webvigil, Subramanian Chelladurai Hari Hara
Computer Science and Engineering Theses
There is a need for selective monitoring, the contents of web pages. Periodical visit for understanding changes to a web page is both inefficient and time consuming. WebVigiL is a system developed for automating the change detection and timely notification of HTML/XML pages based on user specified changes of interest. User interest, specified as a sentinel/profile, is automatically monitored by the system using a combination of learning-based and event-driven techniques. The first prototype concentrated on the functionality of the WebVigiL system. This thesis extends the WebVigiL system in a number of ways. The primary focus of this thesis is the …
Efficient Main Memory Algorithms For Significant Interval And Frequent Episode Discovery, Sagar Hasmukh Savla
Efficient Main Memory Algorithms For Significant Interval And Frequent Episode Discovery, Sagar Hasmukh Savla
Computer Science and Engineering Theses
There is a considerable research on sequential mining of time-series data. Sensor-based applications such as MavHome require prediction of events for automating the environment using time-series data collected over a period of time. In these applications, it is important to predict tight and accurate intervals of interest to effectively automate the application. Also, detection of frequent patterns is needed for the automation of sequence of happenings. Although, there is a considerable body of work on sequential mining of transactional data, most of them deal with time point data and make several iterations over the entire data set for discovering frequently …
Probabilistic Localization Of Mobile Ad Hoc Networks, Rui Huang
Probabilistic Localization Of Mobile Ad Hoc Networks, Rui Huang
Computer Science and Engineering Dissertations
The mobile ad hoc network localization problem deals with estimating the physical location of the nodes that do not have a direct way (e.g., GPS) to determine their own locations. Being an enabling technology that is considered essential to the success of the future implementation of ad hoc networks in the real world, localization is a fundamental problem that needs to be solved with the best possible accuracy and efficiency. For this research, we study the localization problem in its various incarnations such as localization through static beacons, mobile beacons, dynamically deployed beacons and link longevity estimation based on relative …
Evading Existing Stepping Stone Detection Methods Using Buffering, Madhu Venkateshaiah
Evading Existing Stepping Stone Detection Methods Using Buffering, Madhu Venkateshaiah
Computer Science and Engineering Theses
To gain anonymity and complicate their apprehension, attackers launch attacks not from their own systems but from previously compromised systems called stepping stones. An effective way to detect stepping stones is by comparing of incoming and outgoing connections in a network to find correlations. For the sake of simplicity, earlier approaches ignore that an attacker can add chaff to a traffic stream. But in reality, the attacker may be able to modify applications to use cover traffic. We loosen some assumptions made by earlier researchers and propose a simple buffering technique that could be used by an attacker to evade …
A Distributed Sensor Data Management Infrastructure Based On 802.15.4/Zigbee Networks, Tianqiang Li
A Distributed Sensor Data Management Infrastructure Based On 802.15.4/Zigbee Networks, Tianqiang Li
Computer Science and Engineering Theses
Wireless sensor networks consist of a certain number of autonomous devices with sensor, every device has certain detection functionality like light, temperature pressure etc. Communication by using the radio frequency make these spatially distributed devices feasible to oversee the activities in a large scale of area/space. 802.15.4/ZigBee networks are slated to run in the unlicensed frequencies. It is a packet-based radio protocol aimed at very low-cost, battery-operated widgets and sensors that can intercommunicate and send low-bandwidth data to each other. This thesis covers the content of a software solution of data management for an 802.15.4 networks. Its main contribution lies …
Automated Software Testing Using Covering Arrays, Chinmay P. Jayaswal
Automated Software Testing Using Covering Arrays, Chinmay P. Jayaswal
Computer Science and Engineering Theses
Modern society is increasingly dependent on the quality of software systems. Software testing is a widely used approach to ensure software quality. Since exhaustive testing is impractical due to resource constraints, it is necessary to strike a balance between test efforts and quality assurance. Interaction testing is one approach to marrying these two qualities. It characterizes the system under test by a set of parameters and the respective test values (domain size) for each parameter. Instead of testing all possible combinations of values for all the parameters, interaction testing constructs a covering array as a test set to cover all …
Complementing Current Active Queue Management Schemes With Rechoke And Receiver-Window Modification (Rwm), Visvasuresh Govindaswamy
Complementing Current Active Queue Management Schemes With Rechoke And Receiver-Window Modification (Rwm), Visvasuresh Govindaswamy
Computer Science and Engineering Dissertations
Explicit Congestion Notification (ECN) and Active Queue Management (AQM) schemes have been proposed for present-day TCP/IP networks to better manage network congestion. ECN enabled AQMs were shown to have a promising advantage over existing drop-tail queues. However, when implemented, they were susceptible to the following problems: 1) the timeout mechanism or the duration of the reception of three duplicate acknowledgements (ACKs), due to early-dropped packets by these AQMs, delays the response time of TCP (in reducing the offered rate) 2) using ECN with these AQMs has its downsides: i) its messages may get delayed or dropped due to congestion in …
Using Part Of Speech Structure Of Text In The Prediction Of Its Readability, Jagadeesh Kondru
Using Part Of Speech Structure Of Text In The Prediction Of Its Readability, Jagadeesh Kondru
Computer Science and Engineering Theses
Readability formulas predict the reading difficulty associated with text. They typically output a U.S. school grade level that indicates the reading ability required of a person in order for him to comprehend that text. Ability to predict text readability is useful because it helps educators select appropriate texts for students and authors write texts accessible to the audience they target. Existing readability formulas are based on countable aspects of the text such as average sentence length and average word length. We propose a new readability formula, the Readability Index, which is based on the part-of-speech structure of sentences in a …
Evaluating Indexing And Routing Schemes For Spatial Queries In Sensor Networks, Raja Rajeshwari Anugula
Evaluating Indexing And Routing Schemes For Spatial Queries In Sensor Networks, Raja Rajeshwari Anugula
Computer Science and Engineering Theses
Recent advances in low-power sensing devices coupled with widespread availability of wireless ad-hoc networks, has fueled the development of sensor networks. These senor networks have various applications such as to monitor conditions at different locations (temperature, pressure, rainfall, vibrations etc.,), tracking of objects and so on. Each device is equipped with an energy source (usually with a battery), memory, CPU and communication bandwidth, which is severely constrained. Hence each sensor network is comprised of hardware for sensing, software for communication and computational algorithms. Spatial queries are commonly applied to sensor network, for example: "Find the highest temperature sensed in a …
Learning State And Action Space Hierarchies For Reinforcement Learning Using Action-Dependent Partitioning, Mehran Asadi
Learning State And Action Space Hierarchies For Reinforcement Learning Using Action-Dependent Partitioning, Mehran Asadi
Computer Science and Engineering Dissertations
Autonomous systems are often dicult to program. Reinforcement learning (RL) is an attractive alternative, as it allows the agent to learn behavior on the basis of sparse, delayed reward signals provided only when the agent reaches desired goals. Recent attempts to address the dimensionality of RL have turned to principled ways of exploiting temporal abstraction, where decisions are not required at each step, but rather invoke the execution of temporally-extended activities which follow their own policies un- til termination. This leads naturally to hierarchical control architectures and associated learning algorithms. This dissertation reviews several approaches to temporal abstraction and hierarchical …
Context Aware Energy Conservation In Pervasive Computing Environments, Prathiba Joseph
Context Aware Energy Conservation In Pervasive Computing Environments, Prathiba Joseph
Computer Science and Engineering Theses
Extending battery lifetime is one of the most critical and challenging problems in mobile systems. When the mobile device sounds a low battery alarm, the user is given an ultimatum to quickly find a power source or suspend work. The greatest utility of mobile devices is their ability to be used anywhere, and at anytime. But power limitations of these devices seem to hinder this goal. The ever-growing needs of mobile users for increased lifetime of wireless devices imply that emerging wireless systems must be more energy-efficient than ever before. Cyber foraging or remote resource exploitation may be an efficient …
An Application Of Parallel And Distributed Computing Methods To Approximate Pattern Matching Of Genetic Regulatory Motifs, Tushar Kumar Jayantilal
An Application Of Parallel And Distributed Computing Methods To Approximate Pattern Matching Of Genetic Regulatory Motifs, Tushar Kumar Jayantilal
Computer Science and Engineering Theses
Bioinformatics is a relatively new scientific field concerned with providing computational means and support to research in molecular biology and genetics. It draws from many different areas of computer science, including database theory, algorithm design and analysis, and artificial intelligence, to name just a few. In many applications, such as one described in this thesis, a biologist is interested in locating a particular pattern, or sequence motif, in a given string or set of strings over the four-letter DNA alphabet. In this thesis we present an efficient approach to locating promoter and other regulatory sequences in entire genomes or in …
Generalization And Enforcement Of Role-Based Access Control Using A Novel Event-Based Approach, Raman Adaikkalavan
Generalization And Enforcement Of Role-Based Access Control Using A Novel Event-Based Approach, Raman Adaikkalavan
Computer Science and Engineering Dissertations
Protecting information against unauthorized access is a key issue in information system security. Advanced access control models and mechanisms have now become necessary for applications and systems due to emerging acts, such as the Health Insurance Portability and Accountability Act (HIPAA) and the Sarbanes-Oxley Act. Role-Based Access Control (RBAC) is a viable alternative to traditional discretionary and mandatory access control. RBAC has been shown to be cost effective and is being employed in various application domains on account of its characteristics: rich specification, policy neutrality, separation of duty relations, principle of least privilege, and ease of management. Existing RBAC approaches …
A Relational Database Approach For Frequent Subgraph Mining, Subhesh Kumar Pradhan
A Relational Database Approach For Frequent Subgraph Mining, Subhesh Kumar Pradhan
Computer Science and Engineering Theses
Data mining aims at discovering interesting and previously unknown patterns from data sets. Further more, graph-based data mining represents a collection of techniques for mining the relational aspects of data represented as a graph. Complex relationships in data can be represented using graphs and hence graph mining is appropriate for analyzing data that is rich in structural relationships. Database mining of graphs, on the other hand, aims at directly mining graphs stored in a database using SQL queries. Several SQL-based mining algorithms have been developed successfully and their efficiency and scalability have been established. One of them is HDB-Subdue which …
Exception Handling Using Class Diversity, Qizhi Ye
Exception Handling Using Class Diversity, Qizhi Ye
Computer Science and Engineering Theses
Software reliability has been received more and more attention not only in mission critical system but also in commercial software system. Developing robust software must consider faults caused by abnormal situations or exceptions. Although modern programming languages like Java and C++ provide sophisticated exception handling mechanisms for detecting and handling exceptions, many potential runtime exceptions are not caught and handled because runtime exceptions could occur anywhere and could be numerous in a typical program. If an uncaught runtime exception occurs during program execution, then the execution will terminate abnormally, resulting in a system crash. The thesis proposes a framework that …
Simulation Of Sensor Responses Of Advanced Security Systems, Janakiram Natarajan
Simulation Of Sensor Responses Of Advanced Security Systems, Janakiram Natarajan
Computer Science and Engineering Theses
Security systems are becoming an increasingly important area of research. Advanced security detection and surveillance systems that integrates a variety of detection mechanisms, like signals from different kinds of sensors, is expected to yield more accurate assessment than any one sensor analyzed individually. Designing and investigating these systems, to date, has relied primarily on physical deployments and experimentation. While the quality of the results from such efforts is excellent, the need to work with the physical systems directly imposes a substantial research impediment. One obvious possibility for widening the scope of what can be investigated is to employ simulation as …
A Graph-Based Approach For Modeling And Indexing Video Data, Jeongkyu Lee
A Graph-Based Approach For Modeling And Indexing Video Data, Jeongkyu Lee
Computer Science and Engineering Dissertations
With the advances in electronic imaging, storage, networking and computing, the amount of digital video has grown tremendously. The proliferation of video data has led to significant amount of research on techniques and systems for efficient video database management. In particular, extensive research has been done on video data modeling to manage and organize the data that is semantically rich and complicated. However, the enormous amount of data size and its complexity have restricted the progress on video data modeling, indexing and retrieval. In order to get around the problems, we turn to a graph theoretical approach for video database. …
Multiple Object Tracking Using Particle Filters, Hwangryol Ryu
Multiple Object Tracking Using Particle Filters, Hwangryol Ryu
Computer Science and Engineering Theses
We describe a novel extension to the Particle filter algorithm for tracking multiple objects. The recently proposed algorithms and the variants for multiple object tacking algorithms estimate multi-modal posterior distributions that potentially represent the multiple peaks (i.e., multiple tracked objects). However, the speci¯c state representation does not demonstrate birth, death and more importantly partial/complete occlusion of the objects. Furthermore, the weakness of the Particle Filter such that the representation may increasingly bias the posterior density estimates toward objects with dominant likelihood makes the multiple object tracking algorithms more di±cult. To circumvent a sample depletion problem and maintain the computational complexity …
Relative Clock Drift Rate Based Secure Time Synchronization For Wireless Sensor Networks, Jae Sung Choi
Relative Clock Drift Rate Based Secure Time Synchronization For Wireless Sensor Networks, Jae Sung Choi
Computer Science and Engineering Theses
Time synchronization is critical issue to many wireless sensor network applications such that target tracking, TDMA radio scheduling, and secure localization. However, the most of existing time synchronization algorithms in wireless sensor networks did not consider malicious attacks in hostile environments. In this thesis, we propose a Relative Clock Drift Rate Based Secure Time Synchronization (RSTS) schemes to address security problems. RSTS alleviates delay attacks and incorrect time stamp transmissions caused by external or internal malicious attackers. We discuss a simple estimation technique to calculate a relative clock drift rate between sender-receiver clocks, because the estimated relative clock drift rate …
Investigation Of Techniques To Increase The Scalability Of Graph-Based Data Mining Algorithms., Srilatha Inavolu
Investigation Of Techniques To Increase The Scalability Of Graph-Based Data Mining Algorithms., Srilatha Inavolu
Computer Science and Engineering Theses
Frequent subgraph pattern recognition and graph-based relational learning have been an emerging area of data mining research with scientific and commercial applications. At the kernel of these algorithms are the computationally-expensive graph and subgraph isomorphism tests. The graph isomorphism problem consists in deciding whether two graphs are isomorphic i.e., whether there is a one-one mapping between the vertices of the two graphs that respects the edge connections. Many graphs will be depicted quite differently but in actuality have the same inherent structure. This leads to the isomorphism problem. The graph isomorphism problem belongs to the class of NP problems and …
Anytime Top-K Queries On Exact And Fuzzy Data, Bhushan P. Chaudhari
Anytime Top-K Queries On Exact And Fuzzy Data, Bhushan P. Chaudhari
Computer Science and Engineering Theses
Top-k queries on large multi-attribute data sets are fundamental operations in information retrieval and ranking applications. In this thesis, we initiate research on the anytime behavior of top-k algorithms on exact and fuzzy data. In particular given specific topk algorithms we are interested in studying their progress towards identification of the correct result at any point of the algorithms' execution. We adopt a probabilistic approach where we seek to report at any point the scores of the top-k results the algorithm has identified, as well as associate a confidence with this prediction. Such functionality can be a valuable asset when …
Towards Optimum Play-Out Buffering Delay In Voice Over Ip, Ruchir Pramod Shende
Towards Optimum Play-Out Buffering Delay In Voice Over Ip, Ruchir Pramod Shende
Computer Science and Engineering Theses
Voice over Internet Protocol (VoIP) or transmission of real-time voice packets over the Internet is slowly emerging as a cost-effective alternative to the traditional Public Switched Telephone Network (PSTN). However, varying end-to-end delay and packet loss, which are inherent in a packet-switched network like the Internet, lead to relatively lower quality of VoIP calls. The call quality can be improved by adaptively adjusting the play-out buffer at the receiver to reduce the impact of the delay and jitter. A standard play-out strategy uses a weighted moving average of the mean and variance of network delay to adaptively set the play-out …