Computer Sciences Commons^™

Precisely Serializable Snapshot Isolation, Stephen Anthony Revilak

Graduate Doctoral Dissertations

Snapshot Isolation (SI) is a method of database concurrency control that uses timestamps and multiversioning, in preference to pessimistic locking. Since its introduction in 1995, SI has become a popular isolation level, and has been implemented in a variety of database systems: Oracle, Postgres, Microsoft SQL Server, and others. Despite the benefits that SI offers, one of the things it cannot provide is serializability. Past approaches for serializable SI have focused on avoiding dangerous structures (or essential dangerous structures). Dangerous structures are patterns of transaction dependencies that indicate the potential for a non-serializable execution; however, the presence of dangerous structures …

Making An Impact On The Obesity Epidemic By Deploying A Mobile Fitness Suite On The Android Market, Chad Richards

Computer Science and Computer Engineering Undergraduate Honors Theses

The Mobile Fitness Suite aims to make an impact on the obesity epidemic by deploying a set of mobile fitness applications on the Android Market. The thesis details the health and financial issues with the obesity epidemic, along with its causes, and how a set of fitness applications can aid with the obesity epidemic. It also explains the reasons for releasing the program on the Android Market and details each step in the process of deploying a mobile application to the Android Market. Further, it discusses the design and architecture that went into the development of the Mobile Fitness Suite …

The Design & Implementation Of An Abstract Semantic Graph For Statement-Level Dynamic Analysis Of C++ Applications, Edward Duffy

All Dissertations

In this thesis, we describe our system, Hylian, for statement-level analysis,
both static and dynamic, of a C++ application. We begin by extending the
GNU gcc parser to generate parse trees in XML format for each of the
compilation units in a C++ application. We then provide verification that the
generated parse trees are structurally equivalent to the code in the
original C++
application. We use the generated parse trees, together with an augmented
version of the gcc test suite, to recover a grammar for the C++ dialect that
we parse. We use the recovered grammar to generate a schema …

Mechanical And Modular Verification Condition Generation For Object-Based Software, Heather Harton

All Dissertations

The foundational goal of this work is the development of mechanizable proof rules and a verification condition generator based on those rules for modern software. The verification system will be modular so that it is possible to verify the implementation of a component relying upon only the specifications of underlying components that are reused. The system must enable full behavioral verification. The proof rules used to generate verification conditions (VCs) of correctness must be amenable to automation. While automation requires software developers to annotate implementations with assertions, it should not require assistance in the proofs. This research has led to …

Location Cheating: A Security Challenge To Location-Based Social Network Services, Mai Ren

School of Computing: Dissertations, Theses, and Student Research

Location-based mobile social network services such as Foursquare and Gowalla have grown exponentially over the past several years. These location-based services utilize the geographical position to enrich user experiences in a variety of contexts, including location-based searching and location-based mobile advertising. To attract more users, the location-based mobile social network services provide real-world rewards to the user, when a user checks in at a certain venue or location. This gives incentives for users to cheat on their locations.

In this thesis, we investigate the threat of location cheating attacks, find the root cause of the vulnerability, and outline the possible …

Distributed Algorithms For Energy Savings In The Core Network, Lin Liu

School of Computing: Dissertations, Theses, and Student Research

Recently, many efforts have been undertaken to reduce the energy consumption of core networks. Bundle link is a commonly deployed technique in core networks to combine several high-speed physical sublinks into a virtual connection to achieve bandwidth upgrade flexibility and network reliability. The traffic passing through a bundle link can be carried fully over the first few sublinks (bin packing) or evenly distributed over all sublinks (load balancing). In the current network when a bundle link is on, all of its sublinks are on, thus, selectively shutting down a few sublinks during periods of low traffic could save a large …

Processj: A Process-Oriented Programming Language, Matthew Sowders

UNLV Theses, Dissertations, Professional Papers, and Capstones

Java is a general purpose object-oriented programming language that has been widely adopted. Because of its high adoption rate and its lineage as a C-style language, its syntax is familiar to many programmers. The downside is that Java is not natively concurrent. Volumes have been written about concurrent programming in Java; however, concurrent programming is difficult to reason about within an object-oriented paradigm and so is difficult to get right.

occam -π is a general purpose process-oriented programming language. Concurrency is part of the theoretical underpinnings of the language. Concurrency is simple to reason about within an occam -π application …

Parallel Machines Scheduling With Applications To Internet Ad-Slot Placement, Shaista Lubna

UNLV Theses, Dissertations, Professional Papers, and Capstones

We consider a class of problems of scheduling independent jobs on identical, uniform and unrelated parallel machines with an objective of achieving an optimal schedule. The primary focus is on the minimization of the maximum completion time of the jobs, commonly referred to as Makespan (C _max ). We survey and present examples of uniform machines and its applications to the single slot and multiple slots based on bids and budgets.

The Internet is an important advertising medium attracting large number of advertisers and users. When a user searches for a query, a search engine returns a set of results …

Defining, Executing And Visualizing Representative Workflows In A Retail Domain, May Zeineldin

Graduate Theses and Dissertations

Our lives are filled with routine activities that we do more or less on auto-pilot such as driving to work and cooking. This thesis explores a workflow representation as a way to represent such activities of daily living. The domain of a retail store environment is used. Workflows are initially expressed in a structured English representation, then translated into a Petri net notation and implemented in mix of Petri nets, Lua, and C so that the resulting workflows can be displayed as the actions of collections of avatarbots (avatars controlled by programs) in a 3D virtual world, Second Life. One …

Contributions Of Financial Sector Reforms And Credit Supply To Nigerian Agricultural Sector (1978-2009), Anthony O. Onoja, M. E. Onu, S. Ajodo-Ohiemi

CBN Journal of Applied Statistics (JAS)

This study analyzed the trends and pattern of institutional credit supply to agriculture during pre- and post-financial reforms along with their determinants. It then compared the effects of reform policies on access to institutional credits in Nigerian agricultural sector before and after the reforms (1978 - 1985; and 1986 -2009). Relying mainly on time series data from CBN and NBS, it used ordinary least squares method (linear, semi-log and double log) to model the determinants of banking sector lending to the agricultural sector during the review period. The models were subjected to several econometric tests before accepting one. Chow test …

Determinants Of Foreign Reserves In Nigeria: An Autoregressive Distributed Lag Approach, David Irefin, Baba N. Yaaba

CBN Journal of Applied Statistics (JAS)

On global scale, central banks’ holdings of foreign reserves have escalated sharply in recent years. World international reserves holdings have risen significantly from US$1.2 trillion in 1995 to nearly US$10.0 trillion in June 2011. Dominant among these reserves are concentrated in the hands of few countries. Ten major holders of foreign reserves are mostly from Asia. Oil exporting countries in Africa and the Middle East are not left out in this trend. Nigeria’s foreign reserves rose from US$5.5 billion in 1999 to US$62.40 billion in July 2008, making Nigeria the twenty-fourth largest reserves holder in the world. This pace of …

Effects Of Exchange Rate Movements On Economic Growth In Nigeria, Eme O. Akpan, Johnson A. Atan

CBN Journal of Applied Statistics (JAS)

This study investigates the effect of exchange rate movements on real output growth in Nigeria. Based on quarterly series for the period 1986 to 2010, the paper examines the possible direct and indirect relationship between exchange rates and GDP growth. The relationship is derived in two ways using a simultaneous equations model within a fully specified (but small) macroeconomic model. A Generalised Method of Moments (GMM) technique was explored. The estimation results suggest that there is no evidence of a strong direct relationship between changes in exchange rate and output growth. Rather, Nigeria’s economic growth has been directly affected by …

Exchange Rate Volatility In Nigeria: Consistency, Persistency & Severity Analyses, Babatunde Adeoye, Akinwande A. Atanda

CBN Journal of Applied Statistics (JAS)

The adoption of the International Monetary Fund (IMF) Structural Adjustment Programme (SAP) in 1986 resulted in the transition from fixed exchange rate regime to floating exchange rate regime in Nigeria. Ever since, the exchange rate of naira vis-à-vis the U.S dollar has attained varying rates all through different time horizons. On this basis, this study examines the consistency, persistency, and severity (degree) of volatility in exchange rate of Nigerian currency (naira) vis-a-vis the United State dollar using monthly time series data from 1986 to 2008. The standard Purchasing Power Parity (PPP) model was used to analyze the long-run consistency of …

Foreign Private Investment And Economic Growth In Nigeria: A Cointegrated Var And Granger Causality Analysis, F. Z. Abdullahi, S. Ladan, Haruna R. Bakari

CBN Journal of Applied Statistics (JAS)

This research uses a cointegration VAR model to study the contemporaneous long-run dynamics of the impact of Foreign Private Investment (FPI), Interest Rate (INR) and Inflation rate (IFR) on Growth Domestic Products (GDP) in Nigeria for the period January 1970 to December 2009. The Unit Root Test suggests that all the variables are integrated of order 1. The VAR model was appropriately identified using AIC information criteria and the VECM model has exactly one cointegration relation. The study further investigates the causal relationship using the Granger causality analysis of VECM which indicates a uni-directional causality relationship between GDP and FDI …

Banking Sector Credit And Economic Growth In Nigeria: An Empirical Investigation, Aniekan O. Akpansung, Sikiru J. Babalola

CBN Journal of Applied Statistics (JAS)

The paper examines the relationship between banking sector credit and economic growth in Nigeria over the period 1970-2008. The causal links between the pairs of variables of interest were established using Granger causality test while a Two-Stage Least Squares (TSLS) estimation technique was used for the regression models. The results of Granger causality test show evidence of unidirectional causal relationship from GDP to private sector credit (PSC) and from industrial production index (IND) to GDP. Estimated regression models indicate that private sector credit impacts positively on economic growth over the period of coverage in this study. However, lending (interest) rate …

Tracking Web Video Topics: Discovery, Visualization, And Monitoring, Juan Cao, Chong-Wah Ngo, Yong-Dong Zhang, Jin-Tao Li

Research Collection School Of Computing and Information Systems

Despite the massive growth of web-shared videos in Internet, efficient organization and monitoring of videos remains a practical challenge. While nowadays broadcasting channels are keen to monitor online events, identifying topics of interest from huge volume of user uploaded videos and giving recommendation to emerging topics are by no means easy. Specifically, such process involves discovering of new topic, visualization of the topic content, and incremental monitoring of topic evolution. This paper studies the problem from three aspects. First, given a large set of videos collected over months, an efficient algorithm based on salient trajectory extraction on a topic evolution …

Towards Textually Describing Complex Video Contents With Audio-Visual Concept Classifiers, Chun Chet Tan, Yu-Gang Jiang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Automatically generating compact textual descriptions of complex video contents has wide applications. With the recent advancements in automatic audio-visual content recognition, in this paper we explore the technical feasibility of the challenging issue of precisely recounting video contents. Based on cutting-edge automatic recognition techniques, we start from classifying a variety of visual and audio concepts in video contents. According to the classification results, we apply simple rule-based methods to generate textual descriptions of video contents. Results are evaluated by conducting carefully designed user studies. We find that the state-of-the-art visual and audio concept classification, although far from perfect, is able …

Four Perspectives On Architectural Strategy, C. Jason Woodard, Joel West

Research Collection School Of Computing and Information Systems

A recurring theme in the literature on technology and organizations is the concept of mirroring, which posits a duality between technological and organizational design decisions. In this paper we highlight a second, orthogonal duality between components and interfaces: designers of both products and organizations must decide what information to hide within component boundaries and what to expose to other designers. Although the component-interface duality appears in many settings, it presents especially vexing strategic challenges in the design and production of complex digital artifacts. We present a typology of four interlinked perspectives on these kinds of strategic design problems, and discuss …

Tag-Based Social Image Search With Visual-Text Joint Hypergraph Learning, Yue Gao, Meng Wang, Huanboo Luan, Jialie Shen, Shuicheng Yan, Dacheng Tao

Research Collection School Of Computing and Information Systems

Tag-based social image search has attracted great interest and how to order the search results based on relevance level is a research problem. Visual content of images and tags have both been investigated. However, existing methods usually employ tags and visual content separately or sequentially to learn the image relevance. This paper proposes a tag-based image search with visual-text joint hypergraph learning. We simultaneously investigate the bag-of-words and bag-of-visual-words representations of images and accomplish the relevance estimation with a hypergraph learning approach. Each textual or visual word generates a hyperedge in the constructed hypergraph. We conduct experiments with a real-world …

On Two Rfid Privacy Notions And Their Relations, Yingjiu Li, Robert H. Deng, Junzuo Lai, Changshe Ma

Research Collection School Of Computing and Information Systems

Privacy of RFID systems is receiving increasing attention in the RFID community. Basically, there are two kinds of RFID privacy notions in the literature: one based on the indistinguishability of two tags, denoted as ind-privacy, and the other based on the unpredictability of the output of an RFID protocol, denoted as unp*-privacy. In this article, we first revisit the existing unpredictability-based RFID privacy models and point out their limitations. We then propose a new RFID privacy model, denoted as unp*-privacy, based on the indistinguishability of a real tag and a virtual tag. We formally clarify its relationship with the ind-privacy …

Assessing The Impact Of Recommendation Agents On On-Line Consumer Unplanned Purchase Behavior, R. Eric Hostler, Victoria Y. Yoon, Zhiling Guo, Tor Guimaraes, Guisseppi Forgionne

Research Collection School Of Computing and Information Systems

Recommendation agents (RAs) have been used by many Internet businesses such as Amazon and Netflix. However, few authors have studied how consumer behavior is affected by those that make suggestions to online consumers based on their recent shopping behavior. Fewer still have examined the role that RAs play in influencing impulse purchasing decisions online. Our study developed a theoretical model to illustrate the impact of RAs on online consumer behavior. The model was tested through an online shopping simulation which used a collaborative filtering based product RA. Particular attention was paid to the effects of an RA on consumer behavior; …

From Primordial Soup To Platform-Based Competition: Exploring The Emergence Of Products, Systems, And Platforms, C. Jason Woodard, Eric K. Clemons

Research Collection School Of Computing and Information Systems

We use an agent-based NK model to explore the conditions under which standard platforms emerge among competing products. Our findings were inconclusive. We find that the usual Darwinian conditions needed for the emergence of complexity are sufficient to yield a limited reliance upon platforms with a core of common components, simply because evolution causes the population to converge on a set of products that contain combinations that "work well," yielding what we call "coincidental platform emergence." Economies of scale yield more use of common components, or "production platform emergence." Positive participation externalities initially induce the highest degree of platform emergence …

Modeling Social Strength In Social Media Community Via Kernel-Based Learning, Jinfeng Zhuang, Tao Mei, Steven C. H. Hoi, Xian-Sheng Hua, Shipeng Li

Research Collection School Of Computing and Information Systems

Modeling continuous social strength rather than conventional binary social ties in the social network can lead to a more precise and informative description of social relationship among people. In this paper, we study the problem of social strength modeling (SSM) for the users in a social media community, who are typically associated with diverse form of data. In particular, we take Flickr---the most popular online photo sharing community---as an example, in which users are sharing their experiences through substantial amounts of multimodal contents (e.g., photos, tags, geo-locations, friend lists) and social behaviors (e.g., commenting and joining interest groups). Such heterogeneous …

An Effective Approach For Topicspecific Opinion Summarization, Binyang Li, Lanjun Zhou, Wei Gao, Kam-Fai Wong, Zhongyu Wei

Research Collection School Of Computing and Information Systems

Topic-specific opinion summarization (TOS) plays an important role in helping users digest online opinions, which targets to extract a summary of opinion expressions specified by a query, i.e. topic-specific opinionated information (TOI). A fundamental problem in TOS is how to effectively represent the TOI of an opinion so that salient opinions can be summarized to meet user’s preference. Existing approaches for TOS are either limited by the mismatch between topic-specific information and its corresponding opinionated information or lack of ability to measure opinionated information associated with different topics, which in turn affect the performance seriously. In this paper, we represent …

Automated Removal Of Cross Site Scripting Vulnerabilities In Web Applications, Lwin Khin Shar, Hee Beng Kuan Tan

Research Collection School Of Computing and Information Systems

Context: Cross site scripting (XSS) vulnerability is among the top web application vulnerabilities according to recent surveys. This vulnerability occurs when a web application uses inputs received from users in web pages without properly checking them. This allows an attacker to inject malicious scripts in web pages via such inputs such that the scripts perform malicious actions when a client visits the exploited web pages. Such an attack may cause serious security violations such as account hijacking and cookie theft. Current approaches to mitigate this problem mainly focus on effective detection of XSS vulnerabilities in the programs or prevention of …

Understanding And Protecting Privacy: Formal Semantics And Principled Audit Mechanisms, Anupam Datta, Jeremiah Blocki, Nicolas Christin, Henry Deyoung, Deepak Garg, Limin Jia, Dilsun Kaynar, Arunesh Sinha

Research Collection School Of Computing and Information Systems

Privacy has become a significant concern in modern society as personal information about individuals is increasingly collected, used, and shared, often using digital technologies, by a wide range of organizations. Certain information handling practices of organizations that monitor individuals’ activities on the Web, data aggregation companies that compile massive databases of personal information, cell phone companies that collect and use location data about individuals, online social networks and search engines—while enabling useful services—have aroused much indignation and protest in the name of privacy. Similarly, as healthcare organizations are embracing electronic health record systems and patient portals to enable patients, employees, …

Application Oriented Analysis Of Large Scale Datasets, Prashant Shivaji Paymal

Student Work

Diverse application areas, such as social network, epidemiology, and software engineering consist of systems of objects and their relationships. Such systems are generally modeled as graphs. Graphs consist of vertices that represent the objects, and edges that represent the relationships between them. These systems are data intensive and it is important to correctly analyze the data to obtain meaningful information. Combinatorial metrics can provide useful insights for analyzing these systems. In this thesis, we use the graph based metrics such as betweenness centrality, clustering coefficient, articulation points, etc. for analyzing instances of large change in evolving networks (Software Engineering), and …

Context-Based Friend Suggestion In Online Photo-Sharing Community, Ting Yao, Chong-Wah Ngo, Tao Mei

Research Collection School Of Computing and Information Systems

With the popularity of social media, web users tend to spend more time than before for sharing their experience and interest in online photo-sharing sites. The wide variety of sharing behaviors generate different metadata which pose new opportunities for the discovery of communities. We propose a new approach, named context-based friend suggestion, to leverage the diverse form of contextual cues for more effective friend suggestion in the social media community. Different from existing approaches, we consider both visual and geographical cues, and develop two user-based similarity measurements, i.e., visual similarity and geo similarity for characterizing user relationship. The problem of …

Cross Media Hyperlinking For Search Topic Browsing, Song Tan, Chong-Wah Ngo, Hung-Khoon Tan, Lei Pang

Research Collection School Of Computing and Information Systems

With the rapid growth of social media, there are plenty of information sources freely available online for use. Nevertheless, how to synchronize and leverage these diverse forms of information for multimedia applications remains a problem yet to be seriously studied. This paper investigates the synchronization of multiple media content in the physical form of hyperlinking them. The ultimate goal is to develop browsing systems that author search results with rich media information mined from various knowledge sources. The authoring enables the vivid visualization and exploration of different information landscapes inherent in search results. Several key techniques are studied in this …

On The Pooling Of Positive Examples With Ontology For Visual Concept Learning, Shiai Zhu, Chong-Wah Ngo, Yu-Gang Jiang

Research Collection School Of Computing and Information Systems

A common obstacle in effective learning of visual concept classifiers is the scarcity of positive training examples due to expensive labeling cost. This paper explores the sampling of weakly tagged web images for concept learning without human assistance. In particular, ontology knowledge is incorporated for semantic pooling of positive examples from ontologically neighboring concepts. This effectively widens the coverage of the positive samples with visually more diversified content, which is important for learning a good concept classifier. We experiment with two learning strategies: aggregate and incremental. The former strategy re-trains a new classifier by combining existing and newly collected examples, …