Computer Sciences Commons^™

Barriers To Computer Use And Internet Competency Among Homeless Women And Low-Income Women At Risk Of Becoming Homeless, Sondra L. Wildman

Communication & Leadership Dissertations and Theses

As our society relies more and more on digital communication methods, the consequences of not having access to computers and the internet will further erode the ability of homeless women to effectively navigate mainstream venues for social and economic interaction. This study strives to explore the barriers that prevent homeless women, and low-income women at risk of becoming homeless, from optimizing their access to computer and internet resources. A group of fifty homeless women was observed using a computer lab at a daytime shelter, and of this group, five women were interviewed. The theoretical framework of the study utilizes Pierre …

A Ptas For The Uncertain Capacity Knapsack Problem, Matthew Dabney

All Theses

The standard NP-hard knapsack problem can be interpreted as a scheduling problem with n jobs with weights w₁ . . .w_n and processing times p₁ . . . p_n, where our goal is to order the jobs on a single machine so as to maximize the weight of all jobs completing prior to a known common deadline d. In this paper, we study the uncertain capacity knapsack problem (UCKP), a generalization of this problem in which the deadline d is not known with certainty, but rather is provided as a probability distribution, and our goal …

A Reasoning Framework For Dependability In Software Architectures, Tacksoo Im

All Dissertations

The degree to which a software system possesses specified levels of software quality attributes, such as performance and modifiability, often have more influence on the success and failure of those systems than the functional requirements. One method of improving the level of a software quality that a product possesses is to reason about the structure of the software architecture in terms of how well the structure supports the quality. This is accomplished by reasoning through software quality attribute scenarios while designing the software architecture of the system.
As society relies more heavily on software systems, the dependability of those systems …

Debugging Techniques For Locating Defects In Software Architectures, Kyungsoo Im

All Dissertations

The explicit design of the architecture for a software product is a well established part of development projects. As the software architecture descriptions are becoming larger and more complex, there is more likelihood of defects being present in the software architecture. Studies have shown that a defect in the software architecture that has propagated to the development phase is very expensive to fix. To prevent such propagation of defects, this research proposes to provide debugging support for software architecture design.
Debugging is commonly used in programming languages to effectively find the cause of a failure and locate the error to …

A Framework For Virtual Device Driver Development And Virtual Device-Based Performance Modeling, Zachary Jones

All Dissertations

Operating system virtualization tools such as VMWare, XEN, and Linux KVM export only minimally capable SVGA graphics adapters. This paper describes the design and implementation of system
that virtualizes high-performance graphics cards of arbitrary design to support the construction of authentic device drivers. Drivers written for the virtual cards can be used verbatim, without special function calls or kernel modifications, as drivers for real cards, should real cards of the same design exist. While this allows for arbitrary design, it is not able to model performance characteristics. We describe a new kernel system that allows for arbitrarily changing the performance …

Approximation Algorithms For Network Interdiction And Fortification Problems, Adam Whitley

All Dissertations

This dissertation discusses algorithms and results on several NP–hard graph problems which can all be classified as network interdiction and network fortification problems.
The first problem studied, the multiway cut problem, is a generalization of the well–studied s–t min–cut problem, in which we must remove a minimum–cost subset of edges from a graph so that r > 2 designated terminals become disconnected from each other. We investigate an approximation algorithm for general r with a relatively simple analysis guaranteeing an approximation ratio ≤ 1.4647 − epsilon_r, where epsilon_r is a small constant related to the number of terminals …

Evolutionary Strategies For Data Mining, Rose Lowe

All Dissertations

Learning classifier systems (LCS) have been successful in generating rules for solving classification problems in data mining. The rules are of the form IF condition THEN action. The condition encodes the features of the input space and the action encodes the class label. What is lacking in those systems is the ability to express each feature using a function that is appropriate for that feature. The genetic algorithm is capable of doing this but cannot because only one type of membership function
is provided. Thus, the genetic algorithm learns only the shape and placement of the membership function, and in …

Two Essays On The Accounting Treatment For Information Technology Expenditures, Kimberly Swanson Church

Graduate Theses and Dissertations

The current accounting measurement and reporting system is ill-equipped to provide intangible investment information that is decision useful for stakeholders in the information economy. Potentially relevant intangible items are not reported on the balance sheet, since current standards mandate the immediate expensing of these intangible items. Presumably FASB's uncertainty with the fundamental issues of extent and timing of future benefits to the firm has led to concerns with relevance, reliability, and objectivity of capitalizing some intangibles, which results in potential long term value generating expenditures being immediately expensed on the income statement. Prior research has demonstrated extent and timing of …

Dynamic Indexing, Viswada Sripathi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we report on index constructions for large document collections to facilitate the task of search and retrieval. We first report on classical static index construction methods and their shortcomings. We then report on dynamic index construction techniques and their effectiveness.

Dynamic Distributed Programming And Applications To Swap Edge Problem, Feven Z. Andemeskel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Link failure is a common reason for disruption in communication networks. If communication between processes of a weighted distributed network is maintained by a spanning tree T, and if one edge e of T fails, communication can be restored by finding a new spanning tree, T’. If the network is 2-edge connected, T’ can always be constructed by replacing e by a single edge, e’, of the network. We refer to e’ as a swap edge of e.

The best swap edge problem is to find the best choice of e’, that is, that e which causes the new spanning …

Optimized Algorithms For Predictive Range And Knn Queries On Moving Objects, Rui Zhang, H.V. Jagadish, Bing Tian Dai, Kotagiri Ramamohanarao

Research Collection School Of Computing and Information Systems

There have been many studies on management of moving objects recently. Most of them try to optimize the performance of predictive window queries. However, not much attention is paid to two other important query types: the predictive range query and the predictive k nearest neighbor query. In this article, we focus on these two types of queries. The novelty of our work mainly lies in the introduction of the Transformed Minkowski Sum, which can be used to determine whether a moving bounding rectangle intersects a moving circular query region. This enables us to use the traditional tree traversal algorithms to …

3-D Virtual World Education: An Empirical Comparison With Face-To-Face Classroom, Xiaofeng Chen, Keng Siau, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

3-D virtual worlds are increasing in popularity as a means of pedagogical delivery in higher education. In this research, we assess the relative effectiveness of a 3-D virtual world learning environment, Second Life, and traditional face-to-face learning environment. We also assess the efficacy of instructional strategies in these two learning environments and their effects on interactivity, perceived learning, and satisfaction. Our findings suggest that there is an interaction effect of learning environment and instructional strategy. Pair-wise comparisons indicate that when interactive instructional strategy is used, there is no significant difference for perceived learning and satisfaction between 3-D virtual world and …

Terrain Impostors, William Hamilton Hess

Master's Theses

Interactive software applications which need to render large terrain meshes can suffer from slow frame rates if the geometry of the terrain is sufficiently dense. However, the viewing angle to many distant features of the terrain does not change rapidly with respect to time. If the movement of the viewing position is limited to continuous motion and restrained to a known speed, many terrain features may be rendered once in high detail and reused for several frames.

This thesis proposes a method to increase the rendering speed of large complex terrains by splitting the terrain into contiguous chunks. If a …

Dynamic Group Key Exchange Revisited, Guomin Yang, Chik How Tan

Research Collection School Of Computing and Information Systems

In a dynamic group key exchange protocol, besides the basic group setup protocol, there are also a join protocol and a leave protocol, which allow the membership of an existing group to be changed more efficiently than rerunning the group setup protocol. The join and leave protocols should ensure that the session key is updated upon every membership change so that the subsequent sessions are protected from leaving members (backward security) and the previous sessions are protected from joining members (forward security). In this paper, we present a new security model for dynamic group key exchange. Comparing to existing models, …

Ensemble-Based Method For Task 2: Predicting Traffic Jam, Jingrui He, Qing He, Grzegorz Swirszcz, Yiannis Kamarianakis, Rick Lawrence, Wei Shen, Laura Wynter

Research Collection School Of Computing and Information Systems

In this paper, we describe our solution for ICDM 2010 Contest Task 2 (Jams), where the task is to predict future where the next traffic jams will occur in morning rush hour, given data gathered during the initial phase of this peak period. Our solution, which is based on an ensemble approach, finished Second in the final evaluation.

Ibm Power Systems And Service Oriented Architecture At Bank Of America’S Foreign Items Systems Office, Keng Siau, D. Dewester

Research Collection School Of Computing and Information Systems

This is a teaching case on a real life scenario in an organization involving IT solution evaluation and selection. This case involves the Bank of America’s Foreign Items Systems office in Toronto. The officers from the Bank of America’s Foreign Items Systems office in Toronto were discussing how to respond to a Request for Proposal (RFP) from a major U.S. bank to provide foreign currency services. The case discusses three options: Standard J2EE Web Application Global Foreign Currency, Modified J2EE Web Application with Single Sign On, and Service-Oriented Architecture (SOA) via Web Services. The case can be used to complement …

Enhancing Brand Equity Through Flow: Comparison Of 2d Versus 3d Virtual World, Fiona Fui-Hoon Nah, Brenda Eschenbrenner, David Dewester

Research Collection School Of Computing and Information Systems

This research uses the theory of flow to examine the effect of 2D versus 3D virtual world environments on brand equity and use intention. The results suggest that a 3D virtual world environment has both positive (indirect) and negative (direct) effects on brand equity. The positive, indirect effect of the 3D virtual world environment occurs through feelings of telepresence and enjoyment, both of which contribute positively to brand equity and, in turn, induces a higher behavioral intention. The negative, direct effect can be explained using distraction-conflict theory, where attentional conflict is faced by users of a highly interactive and rich …

Understanding Gender Differences In Media Perceptions: A Comparison Of 2d Versus 3d Media, Fiona Fui-Hoon Nah, David Dewester, Brenda Eschenbrenner

Research Collection School Of Computing and Information Systems

We examine gender differences in 2D versus 3D media perceptions. Using the Hunter-Gatherer Theory of Spatial Gender Differences and Jung’s Theory of Psychological Types, we hypothesize differences in men’s and women’s perceptions of skill, challenge, telepresence, and satisfaction with online experiences in 2D versus 3D media interaction. The findings suggest that even though women perceive lower skill levels and greater challenges in using 2D and 3D media than men, women’s sense of telepresence is higher than men in both 2D and 3D media. Women are also more satisfied with their interaction in 2D and 3D media than men.

Revisiting Address Space Randomization, Zhi Wang, Renquan Cheng, Debin Gao

Research Collection School Of Computing and Information Systems

Address space randomization is believed to be a strong defense against memory error exploits. Many code and data objects in a potentially vulnerable program and the system could be randomized, including those on the stack and heap, base address of code, order of functions, PLT, GOT, etc. Randomizing these code and data objects is believed to be effective in obfuscating the addresses in memory to obscure locations of code and data objects. However, attacking techniques have advanced since the introduction of address space randomization. In particular, return-oriented programming has made attacks without injected code much more powerful than what they …

Chosen-Ciphertext Secure Bidirectional Proxy Re-Encryption Schemes Without Pairings, Jian Weng, Huijie, Robert Deng, Shengli Liu, Kefei Chen

Research Collection School Of Computing and Information Systems

Proxy re-encryption realizes delegation of decryption rights, enabling a proxy holding a re-encryption key to convert a ciphertext originally intended for Alice into an encryption of the same message for Bob. Proxy re-encryption is a very useful primitive, having many applications in distributed file systems, outsourced filtering of encrypted spam, access control over network storage, and so on. Lately, Weng et al. proposed the first unidirectional proxy re-encryption scheme without using bilinear pairs. However, Weng et al.'s construction does not possess collusion resilience, in the sense that a coalition of the proxy and the delegatee can recover the delegator's private …

Protecting And Restraining The Third Party In Rfid-Enabled 3pl Supply Chains, Shaoying Cai, Chunhua Su, Yingjiu Li, Robert H. Deng

Research Collection School Of Computing and Information Systems

“Symmetric secret”-based RFID systems are widely adopted in supply chains. In such RFID systems, a reader’s ability to identify a RFID tag relies on the possession of the tag’s secret which is usually only known by its owner. If a “symmetric secret”-based RFID system is deployed in third party logistics (3PL) supply chains, all the three parties (the sender of the goods, the receiver of the goods and the 3PL provider) should have a copy of those tags’ secrets to access the tags. In case the three parties in 3PL supply chain are not all honest, sharing the secrets among …

Evaluation Of Protein Backbone Alphabets : Using Predicted Local Structure For Fold Recognition, Kyong Jin Shim

Research Collection School Of Computing and Information Systems

Optimally combining available information is one of the key challenges in knowledge-driven prediction techniques. In this study, we evaluate six Phi and Psi-based backbone alphabets. We show that the addition of predicted backbone conformations to SVM classifiers can improve fold recognition. Our experimental results show that the inclusion of predicted backbone conformations in our feature representation leads to higher overall accuracy compared to when using amino acid residues alone.

Toward Effective Concept Representation In Decision Support To Improve Patient Safety, Tze-Yun Leong

Research Collection School Of Computing and Information Systems

Patient safety is an emerging, major health care discipline with significance accentuated in the influential Institute of Medicine (IOM) reports in the United States “To Err is Human” and “Crossing the Quality Chasm”. These reports highlighted the danger and prevalence of medical errors and preventable adverse events, explained the three main sources of system-related, human factors-related and cognitive-related errors, and recommended the use of information and decision support technologies to help alleviate the problem. A number of studies and reports from all over the world with similar findings have since followed, culminating in the 55th World Health Assembly Resolution on …

Map Estimation For Graphical Models By Likelihood Maximization, Akshat Kumar, Shlomo Zilberstein

Research Collection School Of Computing and Information Systems

Computing a maximum a posteriori (MAP) assignment in graphical models is a crucial inference problem for many practical applications. Several provably convergent approaches have been successfully developed using linear programming (LP) relaxation of the MAP problem. We present an alternative approach, which transforms the MAP problem into that of inference in a finite mixture of simple Bayes nets. We then derive the Expectation Maximization (EM) algorithm for this mixture that also monotonically increases a lower bound on the MAP assignment until convergence. The update equations for the EM algorithm are remarkably simple, both conceptually and computationally, and can be implemented …

A Type Analysis Of Rewrite Strategies, Azamat Mametjanov

Student Work

Rewrite strategies provide an algorithmic rewriting of terms using strategic compositions of rewrite rules. Due to the programmability of rewrites, errors are often made due to incorrect compositions of rewrites or incorrect application of rewrites to a term within a strategic rewriting program. In practical applications of strategic rewriting, testing and debugging becomes substantially time-intensive for large programs applied to large inputs derived from large term grammars. In essence, determining which rewrite in what position in a term did or did not re comes down to logging, tracing and/or di -like comparison of inputs to outputs. In this thesis, we …

Topical Summarization Of Web Videos By Visual-Text Time-Dependent Alignment, Song Tan, Hung-Khoon Tan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Search engines are used to return a long list of hundreds or even thousands of videos in response to a query topic. Efficient navigation of videos becomes difficult and users often need to painstakingly explore the search list for a gist of the search result. This paper addresses the challenge of topical summarization by providing a timeline-based visualization of videos through matching of heterogeneous sources. To overcome the so called sparse-text problem of web videos, auxiliary information from Google context is exploited. Google Trends is used to predict the milestone events of a topic. Meanwhile, the typical scenes of web …

A Structure First Image Inpainting Approach Based On Self-Organizing Map (Som), Bo Chen, Zhaoxia Wang, Ming Bai, Quan Wang, Zhen Sun

Research Collection School Of Computing and Information Systems

This paper presents a structure first image inpainting method based on self-organizing map (SOM). SOM is employed to find the useful structure information of the damaged image. The useful structure information which includes relevant edges of the image is used to simulate the structure information of the lost or damaged area in the image. The structure information is described by distinct or indistinct curves in an image in this paper. The obtained target curves separate the damaged area of the image into several parts. As soon as each part of the damaged image is restored respectively, the damaged image is …

Traffic Velocity Prediction Using Gps Data: Ieee Icdm Contest Task 3 Report, Wei Shen, Yiannis Kamarianakis, Laura Wynter, Jingrui He, Qing He, Rick Lawrence, Grzegorz Swirszcz

Research Collection School Of Computing and Information Systems

This report summarizes the methodologies and techniques we developed and applied for tackling task 3 of the IEEE ICDM Contest on predicting traffic velocity based on GPS data. The major components of our solution include 1) A pre-processing procedure to map GPS data to the network, 2) A K-nearest neighbor approach for identifying the most similar training hours for every test hour, and 3) A heuristic evaluation framework for optimizing parameters and avoiding over-fitting. Our solution finished Second in the final evaluation.

Time Cost Evaluation For Executing Rfid Authentication Protocols, Kevin Chiew, Yingjiu Li, Tieyan Li, Robert H. Deng, Manfred Aigner

Research Collection School Of Computing and Information Systems

There are various reader/tag authentication protocols proposed for the security of RFID systems. Such a protocol normally contains several rounds of conversations between a tag and a reader and involves cryptographic operations at both reader and tag sides. Currently there is a lack of benchmarks that provide a fair comparison platform for (a) the time cost of cryptographic operations at the tag side and (b) the time cost of data exchange between a reader and a tag, making it impossible to evaluate the total time cost for executing a protocol. Based on our experiments implemented on IAIK UHF tag emulators …

Automobile Exhaust Gas Detection Based On Fuzzy Temperature Compensation System, Zhiyong Wang, Hao Ding, Fufei Hao, Zhaoxia Wang, Zhen Sun, Shujin Li

Research Collection School Of Computing and Information Systems

A temperature compensation scheme of detecting automobile exhaust gas based on fuzzy logic inference is presented in this paper. The principles of the infrared automobile exhaust gas analyzer and the influence of the environmental temperature on analyzer are discussed. A fuzzy inference system is designed to improve the measurement accuracy of the measurement equipment by reducing the measurement errors caused by environmental temperature. The case studies demonstrate the effectiveness of the proposed method. The fuzzy compensation scheme is promising as demonstrated by the simulation results in this paper.