Computer Sciences Commons^™

Efficient Xquery Processing Of Streamed Xml Fragments, Seo Young Ahn

Computer Science and Engineering Theses - Archive

XStreamCast is a push-based streamed XML query processing system that supports multiple servers and clients. The servers broadcast streamed XML data while the clients register to these servers for a specific service and process streamed XML fragments. This thesis presents methods for efficient XQuery processing of streamed XML fragments for the client. The XQuery parser parses the XQuery given by the user first. The client processes the fragments and stores only the needed data for the query. The query is then applied to stored XML fragments. This system can be valuable for managing the memory of the client because it …

A Novel Game Theoretic Framework For Security In Wireless Sensor Networks, Afrand Agah

Computer Science and Engineering Dissertations - Archive

Due to severe resource limitations and often lack of centralized infrastructure, providing security in wireless sensor networks is a great challenge. Misbehavior due to malicious or faulty nodes can significantly degrade the performance of such networks. Therefore, countermeasures against denial of service (DoS) attacks and node misbehavior are essential requirements. We argue that the conventional view of security based on cryptography techniques is not sufficient for securing wireless sensor networks. In this dissertation, we investigate a novel framework by proposing three approaches for security enforcement in such networks that range from prevention of DoS attacks to secure routing. Prevention of …

Querying Microarray Databases, Zoe Alexandra Raja

Computer Science and Engineering Theses - Archive

Microarray technology has rapidly taken a key position among bioinformatics research tools. After the completion of the Human Genome Project, microarray databases have become particularly important to the management and analysis of genomic data. These databases are ideal tools for many research areas involving gene expression patterns under different experimental conditions. This work attempts to assess the querying capabilities of current public microarray database implementations by evaluating their data management, query interfaces, and results presentation. We are not aware of any comparative study available to date that evaluates this important class of biological databases. We examine and evaluate how several …

Repclass: Cluster And Grid Enabled Automatic Classification Of Transposable Elements Identified De Novo In Genome Sequences, Nirmal Ranganathan

Computer Science and Engineering Theses - Archive

In the last few years many computer and laboratory improvements in the production and analysis of DNA sequences have made possible the complete sequencing of whole genomes. This provides us with a wealth of raw genomes that needs to be processed and annotated. 5% to 80% of eukaryotic genomes contain repetitive DNA consisting of transposable elements and tandem repeats which needs to be identified, classified and annotated in order to sequence and annotate the entire genome accurately. Existing tools allow us to identify and annotate transposable elements (TE) but no tool exists for their classification. This thesis work introduces REPCLASS …

Application Of Graph-Based Data Mining To Biological Networks, Chang Hun You

Computer Science and Engineering Theses - Archive

A huge amount of biological data has been generated by long-term research. It is time to start to focus on a system-level understanding of bio-systems. Biological networks are networks of biochemical reactions, containing various objects and their relationships. Understanding of biological networks is a starting point of systems biology. Multi-relational data mining finds the relational patterns in both the entity attributes and relations in the data. A widely used representation for relational data is a graph consisting of vertices and edges between these vertices. Graph-based data mining, as one approach of multi-relational data mining, finds relational patterns in a graph …

Enhancements To The Sam-Grid Infrastructure, Bimal Balan

Computer Science and Engineering Theses - Archive

SAM-Grid is a grid computing infrastructure for high energy physics (HEP) experiments in Fermilab. It is composed of data handling, job management and information management components. There are several challenges when the number of sites participating in the experiment increases. This thesis presents the enhancements made on the SAM-Grid infrastructure. This includes scalability and performance related enhancements. The enhancements mainly affect the batch adapter, monitoring and security layers. As a scalability aspect, Monitoring and Information services required changes to make it easier for monitoring large number of jobs. SAM-Grid is integrated with Sun Grid Engine (SGE) batch system. The batch …

Adaptive Agent Communities For Providing Services In Dynamic Networks, Nayantara Mallesh

Computer Science and Engineering Theses - Archive

New network applications are being created everyday to accommodate diverse user needs. Delivering services to the user in a timely manner taking into account network conditions, resources allocated and network load is a challenge. Multiprotocol Label Switching attempts to overcome best-effort service by providing a method for routing traffic around network congestion, resource reservation and quality of service (QoS) capabilities. IntServ and DiffServ are two other QoS models in use today. IntServ provides per-flow guarantee of quality while DiffServ is based on aggregate service classes. Adaptive Network Service (ANS) is a community of adaptive, collaborating agents residing in the network …

Multi-Dimensional Indexing For Xml Data, Do Youn Kim

Computer Science and Engineering Theses - Archive

The Extensible Markup Language (XML) is becoming a dominant standard for exchanging and retrieving data over the internet. As XML in data exchanging grows, various XML indexing techniques have been proposed for fast and efficient query processing. A survey of theses techniques [9] categorized them into sequence-based indexes, structural indexes, dimension-based indexes and keyword-based indexes based on their properties. In this thesis, we focus on the multi-dimensional XML indexing; more precisely, it can be categorized as a 2-dimension based indexing, which is used in this paper. We studied the properties of multi-dimensional XML indexing and created an implementation to evaluate …

Adaptive, Multimodal, Application Independent User Interfaces For People With Disabilites Using Computers, Padmapriya Sambath

Computer Science and Engineering Theses - Archive

The goal of this thesis is to create more adaptive and flexible user interfaces for people with disabilities and presenting information to everyone and on every device at any time. Delivering information at any time leads to situations such as a person walking with a mobile device having a small screen wanting to make a flight reservation. The intention of presenting information to everybody immediately raises the question of how much of the available information reach people with disabilities. We have suggested a content based user interface language that may be used by external services to interact with the user. …

Service Discovery By Automated Structural And Semantic Matching, Alan Walker

Computer Science and Engineering Theses - Archive

Pervasive computing systems need to locate and use services dynamically. Current models of service location and interaction rely on a fixed contract, or service description, located by name and/or a combination of keywords. This implies a priori agreement on the service description, leading to fragility and the inability for systems to interoperate unless they were built to match an existing standard. This thesis implements a technique for relaxing the fixed contract assumption, so that the nearest match amongst a set of services can be located. The system takes into account structural, data type and naming differences. The naming differences are …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 22, Number 3, November 2005, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Detection Of Covert Channel Encoding In Network Packet Delays, Vincent Berk, Annarita Giani, George Cybenko

Computer Science Technical Reports

Covert channels are mechanisms for communicating information in ways that are difficult to detect. Data exfiltration can be an indication that a computer has been compromised by an attacker even when other intrusion detection schemes have failed to detect a successful attack. Covert timing channels use packet inter-arrival times, not header or payload embedded information, to encode covert messages. This paper investigates the channel capacity of Internet-based timing channels and proposes a methodology for detecting covert timing channels based on how close a source comes to achieving that channel capacity. A statistical approach is then used for the special case …

On Static And Dynamic Partitioning Behavior Of Large-Scale Networks, Derek Leonard, Zhongmei Yao, Xiaoming Wang, Dmitri Loguinov

Computer Science Faculty Publications

In this paper, we analyze the problem of network disconnection in the context of large-scale P2P networks and understand how both static and dynamic patterns of node failure affect the resilience of such graphs. We start by applying classical results from random graph theory to show that a large variety of deterministic and random P2P graphs almost surely (i.e., with probability 1-o(1)) remain connected under random failure if and only if they have no isolated nodes. This simple, yet powerful, result subsequently allows us to derive in closed-form the probability that a P2P network develops isolated nodes, and therefore partitions, …

End-To-End Scheduling Strategies For Aperiodic Tasks In Middleware, Yuanfang Zhang, Chenyang Lu, Christopher Gill, Patrick Lardieri, Gautum Thaker

All Computer Science and Engineering Research

Many mission-critical distributed real-time applicationsmust handle aperiodic tasks with hard end-to-end dead-lines. Existing middleware such as RT-CORBA lacksschedulability analysis and run-time scheduling mecha-nisms that can provide real-time guarantees to aperiodictasks. This paper makes the following contributions to thestate of the art for end-to-end aperiodic scheduling in mid-dleware. First, we compare two approaches to aperiodicscheduling, the deferrable server and the aperiodic utiliza-tion bound, using representative workloads. Numerical re-sults show that the deferrable server analysis is less pes-simistic than the aperiodic utilization bounds when appliedoffline. Second, we propose a practical approach to tuningdeferrable servers for end-to-end tasks. Third, we describedeferrable server mechanisms …

Context Aware Service Oriented Computing In Mobile Ad Hoc Networks, Radu Handorean, Gruia-Catalin Roman, Christopher Gill

All Computer Science and Engineering Research

These days we witness a major shift towards small, mobile devices, capable of wireless communication. Their communication capabilities enable them to form mobile ad hoc networks and share resources and capabilities. Service Oriented Computing (SOC) is a new emerging paradigm for distributed computing that has evolved from object-oriented and component-oriented computing to enable applications distributed within and across organizational boundaries. Services are autonomous computational elements that can be described, published, discovered, and orchestrated for the purpose of developing applications. The application of the SOC model to mobile devices provides a loosely coupled model for distributed processing in a resource-poor and …

Minimum Power Configuration For Wireless Communication In Sensor Networks, Guoliang Xing, Chenyang Lu, Ying Zhang, Qingfeng Huang, Robert Pless

All Computer Science and Engineering Research

This paper proposes the Minimum Power Configuration (MPC) approach to power management in wireless sensor networks. In contrast to earlier research that treats different radio states (transmission/reception/idle) in isolation, MPC integrates them in a joint optimization problem that depends on both the set of active nodes and the transmission power. We propose four approximation algorithms with provable performance bounds and two practical routing protocols. Simulations based on realistic radio models show that the MPC approach can conserve more energy than existing minimum power routing and topology control protocols. Furthermore, it can flexibly adapt to network workload and radio platforms.

Modeling Fuzzy Rules With Description Logics, Sudhir Agarwal, Pascal Hitzler

Computer Science and Engineering Faculty Publications

In real application scenarios, input data and knowledge is often vague. Likewise, it is often the case that exact reasoning over data is impossible due to complex dependencies between input data and target outputs. For practical applications, however, good approximations often suffice, and efficient calculation of an approximate answer is often preferable over complex processing which may take a long time to come up with an exact answer. Fuzzy logic supports both features by providing fuzzy membership functions and fuzzy IF-THEN rule bases. In this paper, we show how fuzzy membership functions and fuzzy rules can be modeled by means …

On Learning Languages From Positive Data And A Limited Number Of Short Counterexamples, Sanjay Jain, Efim Kinber

School of Computer Science & Engineering Faculty Publications

We consider two variants of a model for learning languages in the limit from positive data and a limited number of short negative counterexamples (counterexamples are considered to be short if they are smaller that the largest element of input seen so far). Negative counterexamples to a conjecture are examples which belong to the conjectured language but do not belong to the input language. Within this framework, we explore how/when learners using n short (arbitrary) negative counterexamples can be simulated (or simulate) using least short counterexamples or just `no' answers from a teacher. We also study how a limited number …

Self-Adaptive Scheduler Parameterization, Barry Lawson, Evgenia Smirni

Department of Math & Statistics Technical Report Series

High-end parallel systems present a tremendous research challenge on how to best allocate their resources to match dynamic workload characteristics and user habits that are often unique to each system. Although thoroughly investigated, job scheduling for production systems remains an inexact science, requiring significant experience and intuition from system administrators to properly configure batch schedulers. State-of-the-art schedulers provide many parameters for their configuration, but tuning these to optimize performance and to appropriately respond to the continuously varying characteristics of the workloads can be very difficult — the effects of different parameters and their interactions are often unintuitive.

In this paper, …

Stabilizers: Safe Lightweight Check- Pointing For Concurrent Programs, Lukasz Ziarek, Philip Schatz, Suresh Jagannathan

Department of Computer Science Technical Reports

No abstract provided.

Ft-Rc4: A Robust Security Mechanism For Data Stream Systems, Mohamed Ali, Mohamed Eltabakh, Cristina Nita-Rotaru

Department of Computer Science Technical Reports

No abstract provided.

Hippocratic Data Streams-Concepts, Architectures And Issues, M. H. Ali, M. Y. Eltabakh, Elisa Bertino

Department of Computer Science Technical Reports

No abstract provided.

A Threshold-Based Algorithm For Continuous Monitoring Of K Nearest Neighbors, Kyriakos Mouratidis, Dimitris Papadias, Spiridon Bakiras, Yufei Tao

Research Collection School Of Computing and Information Systems

Assume a set of moving objects and a central server that monitors their positions over time, while processing continuous nearest neighbor queries from geographically distributed clients. In order to always report up-to-date results, the server could constantly obtain the most recent position of all objects. However, this naïve solution requires the transmission of a large number of rapid data streams corresponding to location updates. Intuitively, current information is necessary only for objects that may influence some query result (i.e., they may be included in the nearest neighbor set of some client). Motivated by this observation, we present a threshold-based algorithm …

Query Processing In Spatial Databases Containing Obstacles, Jun Zhang, Dimitris Papadias, Kyriakos Mouratidis, Manli Zhu

Research Collection School Of Computing and Information Systems

Despite the existence of obstacles in many database applications, traditional spatial query processing assumes that points in space are directly reachable and utilizes the Euclidean distance metric. In this paper, we study spatial queries in the presence of obstacles, where the obstructed distance between two points is defined as the length of the shortest path that connects them without crossing any obstacles. We propose efficient algorithms for the most important query types, namely, range search, nearest neighbours, e-distance joins, closest pairs and distance semi-joins, assuming that both data objects and obstacles are indexed by R-trees. The effectiveness of the proposed …

Selective Object Stabilization For Home Video Consumers, Zailiang Pan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper describes a unified approach for video stabilization. The essential goal is to stabilize image sequences that consist of moving foreground objects, which appear frequently in today's home videos captured by hand-held consumer cameras. Our proposed techniques mainly, rely on the analysis of;motion content. Three major components area initialization, segmentation and stabilization. In motion initialization, we propose a novel algorithm to efficiently search for the best possible frame in a sequence to start segmentation. Our segmentation algorithm is based on Expectation-Maximization (EM) framework which provides the mechanism for simultaneous estimation of motion models and their layers of support. Based …

A Context-Sensitive Structural Heuristic For Guided Search Model Checking, Eric G. Mercer, Neha Rungta

Faculty Publications

Software verification using model checking often translates programs into corresponding transition systems that model the program behavior. As software systems continue to grow in complexity and size, exhaustively checking a property on a transition graph becomes difficult. The goal of guided search heuristics in model checking is to find a counterexample to the property being verified as quickly as possible in the transition graph. The FSM distance heuristic builds an interprocedural control flow graph of the program to estimate distance to a possible error state. It ignores calling context and underestimates the true distance to the error.

Exploiting Self-Adaptive Posture-Based Focus Estimation For Lecture Video Editing, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

Head pose plays a special role in estimating a presenter’s focuses and actions for lecture video editing. This paper presents an efficient and robust head pose estimation algorithm to cope with the new challenges arising in the content management of lecture videos. These challenges include speed requirement, low video quality, variant presenting styles and complex settings in modern classrooms. Our algorithm is based on a robust hierarchical representation of skin color clustering and a set of pose templates that are automatically trained. Contextual information is also considered to refine pose estimation. Most importantly, we propose an online learning approach to …

Motion-Based Approach For Bbc Rushes Structuring And Characterization, Chong-Wah Ngo, Zailiang Pan

Research Collection School Of Computing and Information Systems

No abstract provided.

Accurately Extracting Coherent Relevant Passages Using Hidden Markov Models, Jing Jiang, Chengxiang Zhai

Research Collection School Of Computing and Information Systems

In this paper, we present a principled method for accurately extracting coherent relevant passages of variable lengths using HMMs. We show that with appropriate parameter estimation, the HMM method outperforms a number of strong baseline methods on two data sets.

Anonymous Dos-Resistant Access Control Protocol Using Passwords For Wireless Networks, Zhiguo Wan, Robert H. Deng, Feng Bao, Akkihebbal L. Ananda

Research Collection School Of Computing and Information Systems

Wireless networks have gained overwhelming popularity over their wired counterpart due to their great flexibility and convenience, but access control of wireless networks has been a serious problem because of the open medium. Passwords remain the most popular way for access control as well as authentication and key exchange. But existing password-based access control protocols are not satisfactory in that they do not provide DoS-resistance or anonymity. In this paper we analyze the weaknesses of an access control protocol using passwords for wireless networks in IEEE LCN 2001, and propose a different access control protocol using passwords for wireless networks. …