Digital Commons Network^™

A Performance Evaluation Of Alternate Numbering Based Xml Indexing Techniques, Chul Ho Ahn

Computer Science and Engineering Theses - Archive

Since XML became a standard of representing semi-structured data and exchanging format over the web, the sheer volume of XML data has become larger. While relational database represents data as a structured format, XML represents data in a self-describing way as a hierarchical tree structure. For expediting query processing over XML, many different types of indexing techniques have emerged. We will focus on numbering-based indexing techniques in this thesis. We will present performance comparison according to different XPath queries among three distinct numbering based XML indexing named GENE (Generic numbering based), XISS (Range based numbering), and XACC (Dimension based numbering) …

Monitorexplorer: A State-Space Exploration Based Tool To Test Java Monitors Implementations, Vidur Gupta

Computer Science and Engineering Theses - Archive

A monitor is a concurrency construct that encapsulates data. There are many application classes which are written using the Java Monitors and these are difficult to test due to the inherent complexities of the concurrent programs. The key challenge is to be able to trace all possible execution paths and then able to reproduce them for regression testing. Our work explores the state-space of the monitor application. The state space is explored in the depth first fashion. At each state the next possible transition is executed. This process is repeated till a duplicate or invalid state is detected. The key …

Bridging Two Grids: The Sam-Grid/Lcg Integration Project, Tummalapalli Sudhamsh Reddy

Computer Science and Engineering Theses - Archive

SAM-Grid is an integrated data, job, and information management system. SAM-Grid addresses the distributed computing needs of the Dzero experiment at Fermi National Accelerator Laboratory, Batavia, IL. The system typically relies on SAM-Grid specific services deployed at the remote sites in order to manage the computing and storage resources. Such deployment requires special agreements with each resource provider, and it is a labor intensive process. Some members of the Dzero VO also have access to computing resources through the Large Hydron Collider Computing Grid (LCG) infrastructure. Therefore, Dzero users can enter into resource sharing agreements and deployment of standard middleware …

Dial 2004 Working Group Report On Acquisition Quality Control, William A. Barrett, Henry Baird, Frank Le Bourgeois, Xiaofan Lin, George Nagy, Steve Simske, Elisa H. Barney Smith

Faculty Publications

This report summarizes the discussions of the Working Group on Acquisition Quality at the International Workshop on Document Image Analysis for Libraries, Palo Alto, CA, 23-24 January 2004. Acquisition of the image is one of the most time intensive components of forming a digital library, and the quality of the acquisition will affect all later stages of the digital library project. The current state of the art in acquisition is analyzed. Problems and suggested improvements for image acquisition and storage formats and the special problems associated with acquisition from microfilm follows. A list of general suggestions was developed which was …

Separating Lines Of Text In Free-Form Handwritten Historical Documents, William A. Barrett, Douglas J. Kennard

Faculty Publications

We present an approach to finding (and separating) lines of text in free-form handwritten historical document images. After preprocessing, our method uses the count of foreground/background transitions in a binarized image to determine areas of the document that are likely to be text lines. Alternatively, an Adaptive Local Connectivity Map (ALCM) found in the literature can be used for this step of the process. We then use a min-cut/max-flow graph cut algorithm to split up text areas that appear to encompass more than one line of text. After removing text lines containing relatively little text information (or merging them with …

Evaluation Of Time-Varying Availability In Multi-Echelon Spare Parts Systems With Passivation, Hoong Chuin Lau, Huawei Song, Chuen Teck See, Siew Yen Cheng

Research Collection School Of Computing and Information Systems

The popular models for repairable item inventory, both in the literature as well as practical applications, assume that the demands for items are independent of the number of working systems. However this assumption can introduce a serious underestimation of availability when the number of working systems is small, the failure rate is high or the repair time is long. In this paper, we study a multi-echelon repairable item inventory system under the phenomenon of passivation, i.e. serviceable items are passivated (“switched off”) upon system failure. This work is motivated by corrective maintenance of high-cost technical equipment in the miltary. We …

Cs 415: Social Implications Of Computing, Leo Finkelstein

Computer Science & Engineering Syllabi

CS 415 is a communication skills course using as its subject matter current salient issues associated with the social implications of computing. In addition to the course text, you will need to use certain reading materials in the library and elsewhere, and you will be responsible for using concepts and theories provided in class lectures and discussions.

A Practical Password-Based Two-Server Authentication And Key Exchange System, Yanjiang Yang, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

Most password-based user authentication systems place total trust on the authentication server where cleartext passwords or easily derived password verification data are stored in a central database. Such systems are, thus, by no means resilient against offline dictionary attacks initiated at the server side. Compromise of the authentication server by either outsiders or insiders subjects all user passwords to exposure and may have serious legal and financial repercussions to an organization. Recently, several multiserver password systems were proposed to circumvent the single point of vulnerability inherent in the single-server architecture. However, these multiserver systems are difficult to deploy and operate …

Efficient Client-To-Server Assignments For Distributed Virtual Environments, Nguyen Binh Duong Ta, Suiping Zhou

Research Collection School Of Computing and Information Systems

Distributed Virtual Environments (DVEs) are distributed systems that allow multiple geographically distributed clients (users) to interact simultaneously in a computer-generated, shared virtual world. Applications of DVEs can be seen in many areas nowadays, such as online games, military simulations, collaborative designs, etc. To support large-scale DVEs with real-time interactions among thousands or more distributed clients, a geographically distributed server architecture (GDSA) is generally needed, and the virtual world can be partitioned into many distinct zones to distribute the load among the servers. Due to the geographic distributions of clients and servers in such architectures, it is essential to efficiently assign …

Effect Of Changing Requirements: A Tracking Mechanism For The Analysis Workflow, Subhajit Datta, Robert Van Engelen

Research Collection School Of Computing and Information Systems

Managing the effects of changing requirements remains one of the greatest challenges of enterprise software development. The iterative and incremental model provides an expedient framework for addressing such concerns. This paper presents a set of metrics - Mutation Index, Component Set, Dependency Index - and a methodology to measure the effects of requirement changes in the analysis workflow from one iteration to another. Results from a sample case study are included to highlight a usage scenario. Future directions of our work based on this mechanism are also discussed.

Whole Word Phonetic Displays For Speech Articulation Training, Fansheng Meng

Electrical & Computer Engineering Theses & Dissertations

The main objective of this dissertation is to investigate and develop speech recognition technologies for speech training for people with hearing impairments. During the course of this work, a computer aided speech training system for articulation speech training was also designed and implemented. The speech training system places emphasis on displays to improve children's pronunciation of isolated Consonant-Vowel-Consonant (CVC) words, with displays at both the phonetic level and whole word level. This dissertation presents two hybrid methods for combining Hidden Markov Models (HMMs) and Neural Networks (NNs) for speech recognition. The first method uses NN outputs as posterior probability estimators …

A Unified Log-Based Relevance Feedback Scheme For Image Retrieval, Steven Hoi, Michael R. Lyu, Rong Jin

Research Collection School Of Computing and Information Systems

Relevance feedback has emerged as a powerful tool to boost the retrieval performance in content-based image retrieval (CBIR). In the past, most research efforts in this field have focused on designing effective algorithms for traditional relevance feedback. Given that a CBIR system can collect and store users' relevance feedback information in a history log, an image retrieval system should be able to take advantage of the log data of users' feedback to enhance its retrieval performance. In this paper, we propose a unified framework for log-based relevance feedback that integrates the log of feedback data into the traditional relevance feedback …

In-Network Processing Of Nearest Neigbor Queries For Wireless Sensor Networks, Yuxia Yao, Xueyan Tang, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Wireless sensor networks have been widely used for civilian and military applications, such as environmental monitoring and vehicle tracking. The sensor nodes in the network have the abilities to sense, store, compute and communicate. To enable object tracking applications, spatial queries such as nearest neighbor queries are to be supported in these networks. The queries can be injected by the user at any sensor node. Due to the limited power supply for sensor nodes, energy efficiency is the major concern in query processing. Centralized data storage and query processing schemes do not favor energy efficiency. In this paper, we propose …

Understanding Powerpoint Through Rhetoric, Andrea K. Murphy

English Theses & Dissertations

PowerPoint has been described by critics and proponents alike as ubiquitous. This tool, created primarily for the business world, is now found everywhere from elementary school classes to the highest levels of government. Critics of PowerPoint, like Edward Tufte, charge the software with such crimes as the corruption of data and changing the way that people think. Meanwhile, PowerPoint proponents such as Cliff Atkinson and Richard E. Mayer assert PowerPoint's value as an excellent tool that, if designed properly, can take advantage of the promise of research into multimedia theory.

Even as we reconcile these diverse views within a larger …

Experimental And Empirical Perspectives On Grid Resource Allocation For The Singapore Market, Danny Oh, Steven Miller, Nan Hu

Research Collection School Of Computing and Information Systems

In this paper, we describe our work on using the Tycoon system developed by HP Labs to provide a market-based resource allocation and bidding framework for a grid. We discuss how we intend to evaluate the feasibility of the Tycoon system by measuring its economic performance using agent-based simulation experiments for a particular type of grid usage scenario, namely, the digital media market scenario. We will also discuss a related effort in collecting and using real grid data from the National Grid Pilot Platform in Singapore and how we will be using real data collected to derive actual usage patterns …

Sgpm: Static Group Pattern Mining Using Apriori-Like Sliding Window, John Goh, David Taniar, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Mobile user data mining is a field that focuses on extracting interesting pattern and knowledge out from data generated by mobile users. Group pattern is a type of mobile user data mining method. In group pattern mining, group patterns from a given user movement database is found based on spatio-temporal distances. In this paper, we propose an improvement of efficiency using area method for locating mobile users and using sliding window for static group pattern mining. This reduces the complexity of valid group pattern mining problem. We support the use of static method, which uses areas and sliding windows instead …

Enterprise Agility And The Enabling Role Of Information Technology, Eric Overby, Anandhi S. Bharadwaj, V. Sambamurthy

Research Collection School Of Computing and Information Systems

In turbulent environments, enterprise agility, that is, the ability of firms to sense environmental change and respond readily, is an important determinant of firm success. We define and deconstruct enterprise agility, delineate enterprise agility from similar concepts in the business research literature, explore the underlying capabilities that support enterprise agility, explicate the enabling role of information technology (IT) and digital options, and propose a method for measuring enterprise agility. The concepts in this paper are offered as foundational building blocks for the overall research program on enterprise agility and the enabling role of IT.

Anonymous Signature Schemes, Guomin Yang, Duncan S. Wong, Xiaotie Deng, Huaxiong Wang

Research Collection School Of Computing and Information Systems

Digital signature is one of the most important primitives in public key cryptography. It provides authenticity, integrity and non-repudiation to many kinds of applications. On signer privacy however, it is generally unclear or suspicious of whether a signature scheme itself can guarantee the anonymity of the signer. In this paper, we give some affirmative answers to it. We formally define the signer anonymity for digital signature and propose some schemes of this type. We show that a signer anonymous signature scheme can be very useful by proposing a new anonymous key exchange protocol which allows a client Alice to establish …

Fisa: Feature-Based Instance Selection For Imbalanced Text Classification, Aixin Sun, Ee Peng Lim, Boualem Benatallah, Mahbub Hassan

Research Collection School Of Computing and Information Systems

Support Vector Machines (SVM) classifiers are widely used in text classification tasks and these tasks often involve imbalanced training. In this paper, we specifically address the cases where negative training documents significantly outnumber the positive ones. A generic algorithm known as FISA (Feature-based Instance Selection Algorithm), is proposed to select only a subset of negative training documents for training a SVM classifier. With a smaller carefully selected training set, a SVM classifier can be more efficiently trained while delivering comparable or better classification accuracy. In our experiments on the 20-Newsgroups dataset, using only 35% negative training examples and 60% learning …

Searching Substructures With Superimposed Distance, Xifeng Yan, Feida Zhu, Jiawei Han, Philip S. Yu

Research Collection School Of Computing and Information Systems

Efficient indexing techniques have been developed for the exact and approximate substructure search in large scale graph databases. Unfortunately, the retrieval problem of structures with categorical or geometric distance constraints is not solved yet. In this paper, we develop a method called PIS (Partition-based Graph Index and Search) to support similarity search on substructures with superimposed distance constraints. PIS selects discriminative fragments in a query graph and uses an index to prune the graphs that violate the distance constraints. We identify a criterion to distinguish the selectivity of fragments in multiple graphs and develop a partition method to obtain a …

Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design: Quarterly Progress Report January 1-March 31, 2006, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The UNLV developed TRPSEMPro software package can access engineering modeling software, ASPEN Plus through its own interface. The new interface eliminates the user interaction with the complex ASPEN Plus package and also provides input and output results for analysis purpose. The current interface will keep improving on collecting multiple scenario runs and database population.

Two separation processes, acid and plutonium separations, are near completion. The unit operations were finished while some sensitive chemical data for certain species are unknown. Graduate student, Matthew Hodges, continues on finishing those processes using dummy values for those restricted variables. Once the processes complete, researchers …

Determining The Level Of Network Security Awareness Of Utc Students Living On Campus, Alma Cemerlic

Honors Theses

While information technology divisions in various schools often conduct surveys on general computer use, almost no studies have been done that directly targeted the level of Internet security awareness among college students. The National Cyber Security Alliance (NCSA), a not-for-profit, public-private partnership focused on increasing online security awareness, in collaboration with the Government and the Internet industry, organized a number of different projects designed to promote "safe online practices" among college students. However, since research has not been done to investigate the relationship between students' demographics and their Internet security awareness, it is not possible to tell how effective these …

A Selective Approach To Bandwidth Overbooking, Feng Huang

Theses and Dissertations

Overbooking is a technique used by network providers to increase bandwidth utilization. If the overbooking factor is chosen appropriately, additional virtual circuits can be admitted without degrading quality of service for existing customers. Most existing implementations use a single factor to accept a linear fraction of traffic requests. High values of this factor may cause the degradation of quality of service whereas low overbooking factors will result in underutilization of bandwidth. Network providers often select overbooking factors based only on aggregate average virtual circuit utilization. This paper proposes a selective overbooking scheme based on trunk size and usage profile. Experiments …

User Datagram Protocol With Congestion Control, Spencer L. Cox

Theses and Dissertations

Communication through the Internet is one of the dominant methods of exchanging information. Whether at an individual or large corporate level the Internet has become essential to gathering and disseminating information. TCP and UDP are the transport layer protocols responsible for transit of nearly all Internet communications. Due to the growth of real-time audio and video applications, UDP is being used more frequently as a transport protocol. As UDP traffic increases potential problems arise. Unlike TCP, UDP has no mechanism for congestion control leading to wasted bandwidth and poor performance for other competing protocols. This thesis defines a congestion control …

Learning Real-World Problems By Finding Correlated Basis Functions, Adam C. Drake

Theses and Dissertations

Learning algorithms based on the Fourier transform attempt to learn functions by approximating the largest coefficients of their Fourier representations. Nearly all previous work in Fourier-based learning has been in the theoretical realm, where properties of the transform have made it possible to prove many interesting learnability results. The real-world usefulness of Fourier-based methods, however, has not been thoroughly explored. This thesis explores methods for the practical application of Fourier-based learning. The primary contribution of this thesis is a new search algorithm for finding the largest coefficients of a function's Fourier representation. Although the search space is exponentially large, empirical …

Browser-Based Trust Negotiation, Cameron Morris

Theses and Dissertations

Trust negotiation allows two parties on the Internet to establish trust in each other according to the digital credentials thateach other possesses. Traditionally, trust negotiation uses certificates as digital credentials. However, certificates make trust negotiation difficult to use since people rarely have certificates available to them, and they must physically possess and secure all needed certificates in order to negotiate. To avoid these problems, this thesis proposes that credential authorities negotiate on behalf of the user. This thesis defines BrowserBased Trust Negotiation (BBTN) as a method for negotiating with credential authorities using the Secure Assertion Markup Language (SAML).

Encryption Of Computer Peripheral Devices, Kelly Robert Norman

Theses and Dissertations

Computer peripherals, such as keyboards, scanners, printers, cameras, and Personal Data Assistants (PDAs) typically communicate with a host PC via an unencrypted protocol, leaving them vulnerable to eavesdropping techniques, such as keyloggers. An encryption system was developed that is simple enough to be used in peripherals that do not have large amounts of processing power and memory. A software driver loaded in the operating system of the host computer communicates with a simple 8-bit microcontroller in the peripheral device. The driver handles key generation, key exchange, and provides decrypted data to the operating system. A key exchange protocol allows the …

Computer Network Security And Arl Libraries, Deeann Allison, Scott Childers

University of Nebraska-Lincoln Libraries: Faculty Publications

This article reviews current recommendations for computer security practices for staff computing, summarizes current practices in United States Association of Research Libraries and proposes further areas to explore.

Factors Impacting Key Management Effectiveness In Secured Wireless Networks, Yongjoo Shin

Theses and Dissertations

The use of a Public Key Infrastructure (PKI) offers a cryptographic solution that can overcome many, but not all, of the MANET security problems. One of the most critical aspects of a PKI system is how well it implements Key Management. Key Management deals with key generation, key storage, key distribution, key updating, key revocation, and certificate service in accordance with security policies over the lifecycle of the cryptography. The approach supported by traditional PKI works well in fixed wired networks, but it may not appropriate for MANET due to the lack of fixed infrastructure to support the PKI. This …

Surface Realization Using A Featurized Syntactic Statistical Language Model, Thomas L. Packer

Theses and Dissertations

An important challenge in natural language surface realization is the generation of grammatical sentences from incomplete sentence plans. Realization can be broken into a two-stage process consisting of an over-generating rule-based module followed by a ranker that outputs the most probable candidate sentence based on a statistical language model. Thus far, an n-gram language model has been evaluated in this context. More sophisticated syntactic knowledge is expected to improve such a ranker. In this thesis, a new language model based on featurized functional dependency syntax was developed and evaluated. Generation accuracies and cross-entropy for the new language model did not …