Computer Sciences Commons^™

Discrete Groups And The Complex Contact Geometry Of Sl(2, C), Brendan Foreman

Mathematics and Computer Science

We investigate the vertical foliation of the standard complex contact structure on Γ \ Sl(2, C), where Γ is a discrete subgroup. We find that, if Γ is nonelementary, the vertical leaves on Γ \ Sl(2, C) are holomorphic but not regular. However, if Γ is Kleinian, then Γ \ Sl(2, C) contains an open, dense set on which the vertical leaves are regular, complete and biholomorphic to C ∗. If Γ is a uniform lattice, the foliation is nowhere regular, although there are both infinitely many compact and infinitely many nonclosed leaves.

Toward Using Games To Teach Fundamental Computer Science Concepts, Jeffrey Michael Edgington

Electronic Theses and Dissertations

Video and computer games have become an important area of study in the field of education. Games have been designed to teach mathematics, physics, raise social awareness, teach history and geography, and train soldiers in the military. Recent work has created computer games for teaching computer programming and understanding basic algorithms.

We present an investigation where computer games are used to teach two fundamental computer science concepts: boolean expressions and recursion. The games are intended to teach the concepts and not how to implement them in a programming language.

For this investigation, two computer games were created. One is designed …

Integrating Recommender Information In Social Ecosystems Decisions, Renato A C Capuruco, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

The exploration of online social networks whose members share mutual recommendations and interactions is a time-dependent and contextual-based process which aims to predict the social status among members, ultimately improving the network's discoverability to achieve societal gain. To address the difficulties associated with the process, this article presents an integrated recommender model whose statements are time-dependent, interaction-aware, and social context-sensitive. The originality of the proposed model stems from the integration of the predictive recommender, social networks, and interaction components. Each model is developed based on: (1) a time history and decay algorithm to consider the decreasing intensity of recommendations among …

An Empirical Study On The Procedure To Derive Software Quality Estimation Models, Jie Xu, Danny Ho, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

Software quality assurance has been a heated topic for several decades. If factors that influence software quality can be identified, they may provide more insight for better software development management. More precise quality assurance can be achieved by employing resources according to accurate quality estimation at the early stages of a project. In this paper, a general procedure is proposed to derive software quality estimation models and various techniques are presented to accomplish the tasks in respective steps. Several statistical techniques together with machine learning method are utilized to verify the effectiveness of software metrics. Moreover, a neuro-fuzzy approach is …

Pattern Space Maintenance For Data Updates And Interactive Mining, Mengling Feng, Guozhu Dong, Jinyan Li, Yap-Peng Tan, Limsoon Wong

Kno.e.sis Publications

This article addresses the incremental and decremental maintenance of the frequent pattern space. We conduct an in-depth investigation on how the frequent pattern space evolves under both incremental and decremental updates. Based on the evolution analysis, a new data structure, Generator-Enumeration Tree (GE-tree), is developed to facilitate the maintenance of the frequent pattern space. With the concept of GE-tree, we propose two novel algorithms, Pattern Space Maintainer+ (PSM+) and Pattern Space Maintainer− (PSM−), for the incremental and decremental maintenance of frequent patterns. Experimental results demonstrate that the proposed algorithms, on average, outperform the representative state-of-the-art …

Cross-Market Model Adaptation With Pairwise Preference Data For Web Search Ranking, Jing Bai, Fernando Diaz, Yi Chang, Zhaohui Zheng, Keke Chen

Kno.e.sis Publications

Machine-learned ranking techniques automatically learn a complex document ranking function given training data. These techniques have demonstrated the effectiveness and flexibility required of a commercial web search. However, manually labeled training data (with multiple absolute grades) has become the bottleneck for training a quality ranking function, particularly for a new domain. In this paper, we explore the adaptation of machine-learned ranking models across a set of geographically diverse markets with the market-specific pairwise preference data, which can be easily obtained from clickthrough logs. We propose a novel adaptation algorithm, Pairwise-Trada, which is able to adapt ranking models that are trained …

A Verifying Compiler For Embedded Networked Systems, Kalyan Chakradhar Regula

All Theses

Embedded networked devices are required to produce dependable outputs and communicate with peer devices given limited computing resources. These devices monitor and control processes within the physical world. They are used in applications related to environmental monitoring, telecommunications, social networking, and also life-critical applications in domains such as health care, aeronautics, and automotive manufacturing. For such applications, software errors can be costly - both in terms of nancial and human costs. Therefore, software programs installed on these devices must meet the appropriate requirements. To guarantee this, one must verify that the implemented code meets the corresponding specications. Manual trial-and-error validation …

Parallel √3-Subdivision With Animation In Consideration Of Geometric Complexity, Stephen Cooney

All Theses

We look at the broader field of geometric subdivision and the emerging field of parallel computing for the purpose of creating higher visual fidelity at an efficient pace. Primarily, we present a parallel algorithm for √3-Subdivision. When considering animation, we find that it is possible to do subdivision by providing only one variable input, with the rest being considered static. This reduces the amount of data transfer required to continually update a subdividing mesh. We can support recursive subdivision by applying the technique in passes. As a basis for analysis, we look at performance in an OpenCL implementation that utilizes …

Behavioral Animation For Maya Particles Using Steering Forces, Edgar Rodriguez

All Theses

Maya has various built-in solutions for modeling effects. Maya does not, however, offer a built-in solution for modeling so called 'steering behaviors.' While users may rely on particle expressions or scene rigs, these solutions are generally time consuming and ultimately limiting in their cross application. Accordingly, Maya's particle system was extended, by implementing a new force, which can be used to model a set of steering behaviors. The new force was coded in Python and was implemented using Maya's Python Application Programming Interface ('API'). The new force can be used in conjunction with the particle system's existing forces and Maya's …

A Design Science Based Evaluation Framework For Patterns, Stacie Clarke Petter, Deepak Khazanchi, John D. Murphy

Information Systems and Quantitative Analysis Faculty Publications

Patterns were originally developed in the field of architecture as a mechanism for communicating good solutions to recurring classes of problems. Since then, many researchers and practitioners have created patterns to describe effective solutions to problems associated with disparate areas such as virtual project management, human-computer interaction, software development and engineering, and design science research. We believe that the development of patterns is a design science activity in which an artifact (i.e., a pattern) is created to communicate about and improve upon the current state-of-practice. Design science research has two critical components, creation and evaluation of an artifact. While many …

Creating Touchpanel Graphics For Control Systems, Lucas Mcdaniel

All Theses

More often than system designers would like to admit, a discrepancy lies between the implementation of audiovisual control systems and their apparent ease of use to a novice or casual user. System designers and programmers are often hampered by the software tools provided by industry manufacturers and cannot reliably create desirable graphical interfaces that match the level of systems they are asked to program and install.
Popular consumer trends in portable touchscreen devices, pioneered on devices such as the Apple iPhone, light a way forward into a new era of elegantly solving the audiovisual control system graphical user interface problem. …

Learning Personal Agents With Adaptive Player Modeling In Virtual Worlds, Yilin Kang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

There has been growing interest in creating intelligent agents in virtual worlds that do not follow fixed scripts predefined by the developers, but react accordingly based on actions performed by human players during their interaction. In order to achieve this objective, previous approaches have attempted to model the environment and the user’s context directly. However, a critical component for enabling personalized virtual world experience is missing, namely the capability to adapt over time to the habits and eccentricity of a particular player. To address the above issue, this paper presents a cognitive agent with learning player model capability for personalized …

Team Performance Prediction In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

In this study, we propose a comprehensive performance management tool for measuring and reporting operational activities of teams. This study uses performance data of game players and teams in EverQuest II, a popular MMORPG developed by Sony Online Entertainment, to build performance prediction models for task performing teams. The prediction models provide a projection of task performing team's future performance based on the past performance patterns of participating players on the team as well as team characteristics. While the existing game system lacks the ability to predict team-level performance, the prediction models proposed in this study are expected to be …

Merging Schemas In A Collaborative Faceted Classification System, Jianxiang Li

Computer Science Theses & Dissertations

We have developed a system that improves access to a large, growing image collection by allowing users to collaboratively build a global faceted (multi-perspective) classification schema. We are extending our system to support both global and local schemas, where global schema provides a complete and uniform view of the collection whereas local schema provides a personal, possibly incomplete and idiosyncratic view of the collection. We argue that although users usually focus on their personal schemas, it is still desirable to have a global schema for the entire collection even if such local schemas are available. In order to keep the …

Simsight: A Virtual Machine Based Dynamic Call Graph Generator, Xueling Chen

School of Computing: Dissertations, Theses, and Student Research

One problem with using component-based software development approach is that once software modules are reused over generations of products, they form legacy structures that can be challenging to understand, making validating these systems difficult. Therefore, tools and methodologies that enable engineers to see interactions of these software modules will enhance their ability to make these software systems more dependable. To address this need, we propose SimSight, a framework to capture dynamic call graphs in Simics, a widely adopted commercial full-system simulator. Simics is a software system that simulates complete computer systems. Thus, it performs nearly identical tasks to …

Managing Large Data Sets Using Support Vector Machines, Ranjini Srinivas

School of Computing: Dissertations, Theses, and Student Research

Hundreds of Terabytes of CMS (Compact Muon Solenoid) data are being accumulated for storage day by day at the University of Nebraska-Lincoln, which is one of the eight US CMS Tier-2 sites. Managing this data includes retaining useful CMS data sets and clearing storage space for newly arriving data by deleting less useful data sets. This is an important task that is currently being done manually and it requires a large amount of time. The overall objective of this study was to develop a methodology to help identify the data sets to be deleted when there is a requirement for …

An Approach For Ensuring Robust Support For Location Privacy And Identity Inference Protection, Chowdhury Sharif Hasan

Master's Theses (2009 -)

The challenge of preserving a user's location privacy is more important now than ever before with the proliferation of handheld devices and the pervasive use of location based services. To protect location privacy, we must ensure k-anonymity so that the user remains indistinguishable among k-1 other users. There is no better way but to use a location anonymizer (LA) to achieve k-anonymity. However, its knowledge of each user's current location makes it susceptible to be a single-point-of-failure. In this thesis, we propose a formal location privacy framework, termed SafeGrid that can work with or without an LA. In SafeGrid, LA …

Protecting Privacy And Ensuring Security Of Rfid Systems Using Private Authentication Protocols, Md. Endadul Hoque

Master's Theses (2009 -)

Radio Frequency IDentification (RFID) systems have been studied as an emerging technology for automatic identification of objects and assets in various applications ranging from inventory tracking to point of sale applications and from healthcare applications to e-passport. The expansion of RFID technology, however, gives rise to severe security and privacy concerns. To ensure the widespread deployment of this technology, the security and privacy threats must be addressed. However, providing solutions to the security and privacy threats has been a challenge due to extremely inadequate resources of typical RFID tags. Authentication protocols can be a possible solution to secure RFID communications. …

Asynchronous Mips Processors: Educational Simulations, Robert L. Webb

Master's Theses

The system clock has been omnipresent in most mainstream chip designs. While simplifying many design problems the clock has caused the problems of clock skew, high power consumption, electromagnetic interference, and worst-case performance. In recent years, as the timing constraints of synchronous designs have been squeezed ever tighter, the efficiencies of asynchronous designs have become more attractive. By removing the clock, these issues can be mitigated. How- ever, asynchronous designs are generally more complex and difficult to debug. In this paper I discuss the advantages of asynchronous processors and the specifics of some asynchronous designs, outline the roadblocks to asynchronous …

Hardware Microkernels - A Novel Method For Constructing Operating Systems For Heterogeneous Multi-Core Platforms, Jason M. Agron

Graduate Theses and Dissertations

Today's standard operating systems (OSes) do not have the proper structure, nor support for executing on heterogeneous multi- and many-core platforms. These deficiencies manifest in symptomatic issues that range from relatively low-level application binary interface (ABI) compatibility problems, to higher-level concerns such as application programmer interface (API) compatibility, synchronization, and caching issues. These issues in turn reflect back up to the programmer through a lack of a standard set of OS services. Non-uniformities in the hardware architecture are also reflected back into the programming model. In total these issues combined break down the most fundamental benefit of modern operating systems; …

Acm/Springer Mobile Networks And Applications (Monet) Special Issue On “Advanced Mobile Applications And Intelligent Multimedia Systems For Ubi-Com”, Jong Hyuk Park, Shu-Ching Chen, Mieso Denko, Sheikh Iqbal Ahamed

Mathematics, Statistics and Computer Science Faculty Research and Publications

No abstract provided.

A Formal Context Specific Trust Model (Ftm) For Multimedia And Ubiquitous Computing Environment, Sheikh Iqbal Ahamed, Munirul M. Haque, Nilothpal Talukder

Mathematics, Statistics and Computer Science Faculty Research and Publications

In order to ensure secure sharing of resources in an ad-hoc network of handheld devices in a multimedia and ubiquitous computing environment, mutual collaboration is essential. However, the limitations, such as poor storage and computational capability of these multimedia and ubiquitous devices stand as the bottleneck for effective sharing of resources. As a result of this drawback, the adversaries are obtaining access to the new doors for security breaches. Mutual Trust is the weapon used to combat security violations by restricting malicious devices from participating in any interaction in such an open and dynamic environment. In this paper, we present …

Noise Assumptions In Complex-Valued Sense Mr Image Reconstruction, Daniel B. Rowe, Iain P. Bruce

Mathematics, Statistics and Computer Science Faculty Research and Publications

In fMRI, brain images are not measured instantaneously and a volume of images can take two seconds to acquire at a low 64x64 resolution. Significant effort has been put forth on many fronts to decrease image acquisition time including parallel imaging. In parallel imaging, sub-sampled spatial frequency points are measured in parallel and combined to form a single image. Measurement time is decreased at the expense of increased image reconstruction difficulty and time. One significant parallel imaging technique known as SENSE utilizes a complex-valued regression coefficient estimation process with transposes replaced by conjugate transposes. However, in SENSE the noise structure …

Towards Secure And Scalable Tag Search Approaches For Current And Next Generation Rfid Systems, Farzana Rahman

Master's Theses (2009 -)

The technology behind Radio Frequency Identification (RFID) has been around for a while, but dropping tag prices and standardization efforts are finally facilitating the expansion of RFID systems. The massive adoption of this technology is taking us closer to the well known ubiquitous computing scenarios. However, the widespread deployment of RFID technology also gives rise to significant user security issues. One possible solution to these challenges is the use of secure authentication protocols to protect RFID communications. A natural extension of RFID authentication is RFID tag searching, where a reader needs to search for a particular RFID tag out of …

Windows Azure: Using Windows Azure's Service Bus To Solve Data Security Issues, Don Chambers

Theses and Dissertations

Many of the largest technology companies are heavily investing in Cloud Computing technology, making this a major force in the realm of software development. However, this software paradigm brings with it significant data related security issues. This paper discusses some of these security issues and presents a solution. The solution calls for storing data outside of the cloud, and under the control of the cloud consumer. In addition, the solution provides the ability to manipulate data using only the standard HTTP ports that are typically opened at most locations. This solution is implemented using Microsoft's Windows Azure Cloud Computing operating …

Visual Occam: High Level Visualization And Design Of Process Networks, Mikolaj M. Slomka

UNLV Theses, Dissertations, Professional Papers, and Capstones

With networks, multiprocessors, and multi-threaded systems becoming more common in our world it is increasingly evident that concurrent programming is not something to be ignored or marginalized even though many takes on concurrency (mainly by means of monitors or shared resources) have proven to be difficult to deal with on large scales. Thankfully, a good deal of work has already been done to combat this, through CSP, occam, and other such derivatives, to produce a scalable process oriented paradigm. Still, it is cumbersome to attempt to deal with the intricacies of such communicating networks down to every minutia; if, instead, …

Distributed Storage And Queryng Techniques For A Semantic Web Of Scientific Workflow Provenance, Jaime Alberto Navarro

Theses and Dissertations - UTB/UTPA

In scientific workflow environments, scientists depend on provenance, which records the history of an experiment. Resource Description Framework is frequently used to represent provenance based on vocabularies such as the Open Provenance Model. For complex scientific workflows that generate large amounts of RDF triples, single-machine provenance management becomes inadequate over time. In this thesis, we research how HBase capabilities can be leveraged for distributed storage and querying of provenance data represented in RDF. We architect the ProvBase system that incorporates an HBase/Hadoop backend, propose a storage schema to hold provenance triples, and design querying algorithms to evaluate SPARQL queries in …

Dnagents: Genetically Engineered Intelligent Mobile Agents, Jeremy Otho Kackley

Dissertations

Mobile agents are a useful paradigm for network coding providing many advantages and disadvantages. Unfortunately, widespread adoption of mobile agents has been hampered by the disadvantages, which could be said to outweigh the advantages. There is a variety of ongoing work to address these issues, and this is discussed. Ultimately, genetic algorithms are selected as the most interesting potential avenue. Genetic algorithms have many potential benefits for mobile agents. The primary benefit is the potential for agents to become even more adaptive to situational changes in the environment and/or emergent security risks. There are secondary benefits such as the natural …

Investigating Perceptions Of A Location-Based Annotation System, Huynh Nhu Hop Quach, Khasfariyati Razikin, Dion Hoe-Lian Goh, Thi Nhu Quynh Kim, Tan Phat Pham, Yin-Leng Theng, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

We introduce MobiTOP, a Web-based system for organizing and retrieving hierarchical location-based annotations. Each annotation contains multimedia content (such as text, images, video) associated with a location, and users are able to annotate existing annotations to an arbitrary depth, in effect creating a hierarchy. An evaluation was conducted on a group of potential users to ascertain their perceptions of the usability of the application. The results were generally positive and the majority of the participants saw MobiTOP as a useful platform to share location-based information. We conclude with implications of our work and opportunities for future research.

Distributed Route Planning And Scheduling Via Hybrid Conflict Resolution, Ramesh Thangarajoo, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In this paper, we discuss the problem of route planning and scheduling by a group of agents. Each agent is responsible for designing a route plan and schedule over a geographical network, and the goal is to obtain a conflict-free plan/schedule that optimizes a global objective. We present a hybrid conflict resolution method that involves coalition formation and distributed constraint satisfaction depending on the level of coupling between agents. We show how this approach can be effectively applied to solve a distributed convoy movement planning problem.