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2012

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Articles 481 - 510 of 1947

Full-Text Articles in Computer Sciences

Hadoop And Hive As Scalable Alternatives To Rdbms: A Case Study, Marissa Rae Hollingsworth Aug 2012

Hadoop And Hive As Scalable Alternatives To Rdbms: A Case Study, Marissa Rae Hollingsworth

Computer Science Graduate Projects and Theses

While high-performance, cost-effective data management solutions, such as Hadoop, exist for Big Data analysis, small and medium businesses with moderate-sized data sets would also like to implement low budget data management systems that will perform well on existing data and scale as the amount of accumulated data increases. Parallel database management systems may provide a high-performance solution, but are expensive and complex to implement. The purpose of this project was to compare the scalability of open-source relational database management systems and distributed data management systems for small and medium data sets. To make this comparison, a business intelligence case study …


How To Define Mean, Variance, Etc., For Heavy-Tailed Distributions: A Fractal-Motivated Approach, Vladik Kreinovich, Olga Kosheleva Aug 2012

How To Define Mean, Variance, Etc., For Heavy-Tailed Distributions: A Fractal-Motivated Approach, Vladik Kreinovich, Olga Kosheleva

Departmental Technical Reports (CS)

In many practical situations, we encounter heavy-tailed distributions for which the variance -- and even sometimes the mean -- are infinite. We propose a fractal-motivated approach that enables us to gauge the mean and variance of such distributions.


A New Algorithm For Dna Motif Detection, Ran Ding Aug 2012

A New Algorithm For Dna Motif Detection, Ran Ding

Theses and Dissertations - UTB/UTPA

Nowadays, people are more and more concentrated on the research of deoxyribonucleic acid(DNA). And a very important problem is how to identify the DNA performance. A DNA sequence contains lots of genes, and every gene has a regulatory region. This regulatory region contains the transcription factor binding sites (TFBS) which is also known as motif. How to identify this motif becomes a very important problem. There are many efficient methods and tools are dedicated to the research of DNA motif detection. In this paper, we will introduce a new method of DNA motif detection which basically is an advanced approximate …


Measuring The Impact Of Narrative On Player's Presence And Immersion In A First Person Game Environment, Raul Huerta Aug 2012

Measuring The Impact Of Narrative On Player's Presence And Immersion In A First Person Game Environment, Raul Huerta

Theses and Dissertations - UTB/UTPA

In the virtual environments (VE) literature, presence has been described as the feeling whereby an individual feels as if he or she is actually in the VE. In the videogame literature, the related concept of immersion is viewed as an effect facilitating player engagement. This thesis examines how narrative and graphics quality influence presence and immersion in a first person game. Three levels of narrative and graphics quality are used in an empirical study: text narrative with high quality graphics, no text narrative with high quality graphics, and no text narrative with low quality graphics. Results showed that there is …


Tinypack Xml: Real Time Xml Compression For Wireless Sensor Networks, Tommy Szalapski, Sanjay Madria, Mark Linderman Aug 2012

Tinypack Xml: Real Time Xml Compression For Wireless Sensor Networks, Tommy Szalapski, Sanjay Madria, Mark Linderman

Computer Science Faculty Research & Creative Works

Wireless networks possess significant limitations in bandwidth. Additionally, real-time networks cannot tolerate high latency. While some good XML compression algorithms exist, there remains a need for methods that reduce latency and bandwidth usage further in real time wireless applications. This paper presents a new compression scheme which reduces bandwidth while minimizing latency of XML data while in transit. XML structural data is reduced to format strings and arguments are sent as they are generated using modifications of real-time compression techniques specific to each data type. Methods are introduced to gracefully handle lost data in environments where delivery of all packets …


A Highly Optimized Algorithm For Continuous Intersection Join Queries Over Moving Objects, Rui Zhang, Jianzhong Qi, Dan Lin, Wei Wang, Raymond Chi Wing Wong Aug 2012

A Highly Optimized Algorithm For Continuous Intersection Join Queries Over Moving Objects, Rui Zhang, Jianzhong Qi, Dan Lin, Wei Wang, Raymond Chi Wing Wong

Computer Science Faculty Research & Creative Works

Given two sets of moving objects with nonzero extents, the continuous intersection joins query reports every pair of intersecting objects, one from each of the two moving object sets, for every timestamp. This type of queries is important for a number of applications, e. g., in the multi-billion-dollar computer game industry, massively multiplayer online games like World of Warcraft need to monitor the intersection among players' attack ranges and render players' interaction in real time. the computational cost of a straightforward algorithm or an algorithm adapted from another query type is prohibitive, and answering the query in real time poses …


Mësimi Elektronik Në Sistemin Arsimorë Në Kosovë Në Të Gjitha Nivelet, Besim Shala Aug 2012

Mësimi Elektronik Në Sistemin Arsimorë Në Kosovë Në Të Gjitha Nivelet, Besim Shala

Theses and Dissertations

E-mësimi është një qasje e re e cila përmban në vete të mësuarit në njërën anë dhe teknologjinë informative dhe kompjuterët në anën tjetër. Është shkrirje e të mësuarit dhe internetit në një vend.

Ky portal është metoda më efikase dhe e avancuar për qasje elektronike në kërkimet shkencore, shkëmbime informacionesh, interaktivitet mes studentëve dhe profesorëve, video ligjërata, librari elektronik dhe forume.

Studimi online nga distanca, është portali mësimi elektronikë e cila edhe nëse jeni i punësuar dhe nuk mund ti vijoni ligjëratat ju mundëson të studioni nga rehatia e zyrës, apo shtëpisë suaj.

Kjo platformë është metodë më e …


Using Attribute Behavior Diversity To Build Accurate Decision Tree Committees For Microarray Data, Qian Han, Guozhu Dong Aug 2012

Using Attribute Behavior Diversity To Build Accurate Decision Tree Committees For Microarray Data, Qian Han, Guozhu Dong

Kno.e.sis Publications

DNA microarrays (gene chips), frequently used in biological and medical studies, measure the expressions of thousands of genes per sample. Using microarray data to build accurate classifiers for diseases is an important task. This paper introduces an algorithm, called Committee of Decision Trees by Attribute Behavior Diversity (CABD), to build highly accurate ensembles of decision trees for such data. Since a committee's accuracy is greatly influenced by the diversity among its member classifiers, CABD uses two new ideas to "optimize" that diversity, namely (1) the concept of attribute behavior–based similarity between attributes, and (2) …


Software Testability Measure For Sae Architecture Analysis And Design Language (Aadl)Software Testability Measure For Sae Architecture Analysis And Design Language (Aadl), Hung Vo Aug 2012

Software Testability Measure For Sae Architecture Analysis And Design Language (Aadl)Software Testability Measure For Sae Architecture Analysis And Design Language (Aadl), Hung Vo

All Theses

Testability is an important quality attribute of software, especially for critical systems such as avionics, medical, and automotive. Improvement in the early testability of software architecture, the first artifact of the software system, will help reduce issues and costs later in the development process.
AADL, an architecture analysis description language suitable for critical embedded, real-time systems, can be used for design documentation, analysis and code generation. Because the capability of AADL can be extended, it is possible to add new analyses to its core language. Tools such as the Open Source AADL Tool Environment (OSATE) provide plugins for processing AADL …


The Case For Cloud-Enabled Mobile Sensing Services, Sougata Sen, Archan Misra, Rajesh Krishna Balan, Lipyeow Lim Aug 2012

The Case For Cloud-Enabled Mobile Sensing Services, Sougata Sen, Archan Misra, Rajesh Krishna Balan, Lipyeow Lim

Research Collection School Of Computing and Information Systems

We make the case for cloud-enabled mobile sensing services that support an emerging application class, one which infers near-real time collective context using sensor data obtained continuously from a large set of consumer mobile devices. We present the high-level architecture and functional requirements for such a mobile sensing service, and argue that such a service can significantly improve the scalability and energy-efficiency of large-scale mobile sensing by coordinating the sensing & processing tasks across multiple devices. We then focus specifically on the problem of energy efficiency and provide early exemplars of how optimizing query execution jointly over multiple phones can …


Toward Large-Scale Agent Guidance In An Urban Taxi Service, Agussurja Lucas, Hoong Chuin Lau Aug 2012

Toward Large-Scale Agent Guidance In An Urban Taxi Service, Agussurja Lucas, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Empty taxi cruising represents a wastage of resources in the context of urban taxi services. In this work, we seek to minimize such wastage. An analysis of a large trace of taxi operations reveals that the services’ inefficiency is caused by drivers’ greedy cruising behavior. We model the existing system as a continuous time Markov chain. To address the problem, we propose that each taxi be equipped with an intelligent agent that will guide the driver when cruising for passengers. Then, drawing from AI literature on multiagent planning, we explore two possible ways to compute such guidance. The first formulation …


Investment Timing For Mobile Payment Systems, Robert J. Kauffman, Jun Liu, Dan Ma Aug 2012

Investment Timing For Mobile Payment Systems, Robert J. Kauffman, Jun Liu, Dan Ma

Research Collection School Of Computing and Information Systems

The recent launch of Google Wallet has brought the issue of technology solutions in the mobile payment (m-payment) area to the forefront. In deciding whether and when to adopt m-payment technology, senior managers in banks are naturally concerned about uncertainties regarding future market conditions, technology standards, and consumer and merchant responses, especially their willingness to adopt. This study applies economic theory and modeling for decision-making under uncertainty to bank investments in mobile payment technology. We assess the projected benefits and costs of investment as a continuous-time stochastic process to determine optimal investment timing. We find that the value of waiting …


Locating And Protecting Facilities Subject To Random Disruptions And Attacks, Hugh Medal Aug 2012

Locating And Protecting Facilities Subject To Random Disruptions And Attacks, Hugh Medal

Graduate Theses and Dissertations

Recent events such as the 2011 Tohoku earthquake and tsunami in Japan have revealed the vulnerability of networks such as supply chains to disruptive events. In particular, it has become apparent that the failure of a few elements of an infrastructure system can cause a system-wide disruption. Thus, it is important to learn more about which elements of infrastructure systems are most critical and how to protect an infrastructure system from the effects of a disruption. This dissertation seeks to enhance the understanding of how to design and protect networked infrastructure systems from disruptions by developing new mathematical models and …


Who Wears Me? Bioimpedance As A Passive Biometric, Cory Cornelius, Jacob Sorber, Ronald Peterson, Joe Skinner, Ryan Halter, David Kotz Aug 2012

Who Wears Me? Bioimpedance As A Passive Biometric, Cory Cornelius, Jacob Sorber, Ronald Peterson, Joe Skinner, Ryan Halter, David Kotz

Dartmouth Scholarship

Mobile and wearable systems for monitoring health are becoming common. If such an mHealth system knows the identity of its wearer, the system can properly label and store data collected by the system. Existing recognition schemes for such mobile applications and pervasive devices are not particularly usable – they require ıt active engagement with the person (e.g., the input of passwords), or they are too easy to fool (e.g., they depend on the presence of a device that is easily stolen or lost). \par We present a wearable sensor to passively recognize people. Our sensor uses the unique electrical properties …


Simulation, Development And Deployment Of Mobile Wireless Sensor Networks For Migratory Bird Tracking, William P. Bennett Jr. Aug 2012

Simulation, Development And Deployment Of Mobile Wireless Sensor Networks For Migratory Bird Tracking, William P. Bennett Jr.

School of Computing: Dissertations, Theses, and Student Research

This thesis presents CraneTracker, a multi-modal sensing and communication system for monitoring migratory species at the continental level. By exploiting the robust and extensive cellular infrastructure across the continent, traditional mobile wireless sensor networks can be extended to enable reliable, low-cost monitoring of migratory species. The developed multi-tier architecture yields ecologists with unconventional behavior information not furnished by alternative tracking systems at such a large scale and for a low-cost. The simulation, development and implementation of the CraneTracker software system is presented. The system is shown effective through multiple proxy deployments on wildlife and has been operational for 10 months …


The Future Of Citizen Science: Emerging Technologies And Shifting Paradigms, Greg Newman, Andrea Wiggins, Alycia Crall, Eric Graham, Sarah Newman, Kevin Crowston Aug 2012

The Future Of Citizen Science: Emerging Technologies And Shifting Paradigms, Greg Newman, Andrea Wiggins, Alycia Crall, Eric Graham, Sarah Newman, Kevin Crowston

Information Systems and Quantitative Analysis Faculty Publications

Citizen science creates a nexus between science and education that, when coupled with emerging technologies, expands the frontiers of ecological research and public engagement. Using representative technologies and other examples, we examine the future of citizen science in terms of its research processes, program and participant cultures, and scientific communities. Future citizen‐science projects will likely be influenced by sociocultural issues related to new technologies and will continue to face practical programmatic challenges. We foresee networked, open science and the use of online computer/video gaming as important tools to engage non‐traditional audiences, and offer recommendations to help prepare project managers for …


Ethical Considerations For Virtual Worlds, Alanah Mitchell, Deepak Khazanchi Aug 2012

Ethical Considerations For Virtual Worlds, Alanah Mitchell, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

Metaverses, like Second Life and Teleplace, and the inherent technology capabilities that they offer continue to be of interest for researchers, practitioners, and educators. Due to this trend, and the uncertainty regarding immersive virtual experiences as contrasted with face-to-face experiences, there is a need to further understand the ethical challenges associated with this virtual context. This paper presents a starting point for discussing ethics in virtual worlds. Specifically, we review virtual worlds and their unique technology capabilities as well as the ethical considerations that arise due to these unique capabilities.


Opportunistic Random Media Access In Wlans, Chong Tang Aug 2012

Opportunistic Random Media Access In Wlans, Chong Tang

Master's Theses

This thesis proposes a new medium access protocol for IEEE 802.11 wireless local area networks, which is called opp01tunistic medium access. The protocol changes the media access opportunities of nodes by adjusting the contention window dynamically according to the different bit rates. Thereby, the protocol can reduce collision and improve throughput significantly. The n·aditional IEEE 802.11 standards access channel with binary exponential back-off algorithm and all nodes choose the back-off interval from the same initial range. The new protocol in this thesis divides nodes as well as contention windows in proportion to data rate. It offers three methods to group …


Fast And Efficient Classification, Tracking, And Simulation In Wireless Sensor Networks, Hao Jiang Aug 2012

Fast And Efficient Classification, Tracking, And Simulation In Wireless Sensor Networks, Hao Jiang

All Dissertations

Wireless sensor networks are composed of large numbers of resource-lean sensors that collect low-level inputs from the physical world. The applications present challenges for programmers. On the one hand, lightweight algorithms are required given the limited capacity of the constituent devices. On the other, the algorithms must be scalable to accommodate large networks. In this thesis, we focus on the design and implementation of fast and lean (yet scalable) algorithms for classification, simulation, and target tracking in the context of wireless sensor networks. We briefly consider each of these challenges in turn.
The first challenge is to achieve high precision …


A Domain Specific Model For Generating Etl Workflows From Business Intents, Wesley Deneke Aug 2012

A Domain Specific Model For Generating Etl Workflows From Business Intents, Wesley Deneke

Graduate Theses and Dissertations

Extract-Transform-Load (ETL) tools have provided organizations with the ability to build and maintain workflows (consisting of graphs of data transformation tasks) that can process the flood of digital data. Currently, however, the specification of ETL workflows is largely manual, human time intensive, and error prone. As these workflows become increasingly complex, the users that build and maintain them must retain an increasing amount of knowledge specific to how to produce solutions to business objectives using their domain's ETL workflow system. A program that can reduce the human time and expertise required to define such workflows, producing accurate ETL solutions with …


Node Filtering And Face Routing For Sensor Network, Umang Amatya Aug 2012

Node Filtering And Face Routing For Sensor Network, Umang Amatya

UNLV Theses, Dissertations, Professional Papers, and Capstones

Greedy forward routing and face routing algorithms have been extensively used for sending messages in sensor networks. In this thesis, we consider the problem of filtering redundant nodes in a sensor network as a pre-processing step for face routing. We propose two algorithms for identifying redundant nodes. We test the performance of proposed filtering algorithms on generated networks. The prototype algorithm for testing the proposed algorithms has been implemented in the Java programming language. Experimental investigation shows that the proposed filtering algorithms are effective in removing redundant nodes without compromising the network connectivity.


Cpu Scheduling For Power/Energy Management On Heterogeneous Multicore Processors, Rajesh Patel Aug 2012

Cpu Scheduling For Power/Energy Management On Heterogeneous Multicore Processors, Rajesh Patel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Power and energy have become increasingly important concerns in the design and implementation of today's multicore/manycore chips. Many methods have been proposed to reduce a microprocessor's power usage and associated heat dissipation, including scaling a core's operating frequency. However, these techniques do not consider the dynamic performance characteristics of an executing process at runtime, the execution characteristics of the entire task to which this process belongs, the process's priority, the process's cache miss/cache reference ratio, the number of context switches and CPU migrations generated by the process, nor the system load. Also, many of the techniques that employ dynamic frequency …


Boosting Multi-Kernel Locality-Sensitive Hashing For Scalable Image Retrieval, Hao Xia, Steven C. H. Hoi, Pengcheng Wu, Rong Jin Aug 2012

Boosting Multi-Kernel Locality-Sensitive Hashing For Scalable Image Retrieval, Hao Xia, Steven C. H. Hoi, Pengcheng Wu, Rong Jin

Research Collection School Of Computing and Information Systems

Similarity search is a key challenge for multimedia retrieval applications where data are usually represented in high-dimensional space. Among various algorithms proposed for similarity search in high-dimensional space, Locality-Sensitive Hashing (LSH) is the most popular one, which recently has been extended to Kernelized Locality-Sensitive Hashing (KLSH) by exploiting kernel similarity for better retrieval efficacy. Typically, KLSH works only with a single kernel, which is often limited in real-world multimedia applications, where data may originate from multiple resources or can be represented in several different forms. For example, in content-based multimedia retrieval, a variety of features can be extracted to represent …


Palantir: Early Detection Of Development Conflicts Arising From Parallel Code Changes, Anita Sarma, D F. Redmiles, Andre Van Der Hoek Aug 2012

Palantir: Early Detection Of Development Conflicts Arising From Parallel Code Changes, Anita Sarma, D F. Redmiles, Andre Van Der Hoek

School of Computing: Faculty Publications

The earlier a conflict is detected, the easier it is to resolve—this is the main precept of workspace awareness. Workspace awareness seeks to provide users with information of relevant ongoing parallel changes occurring in private workspaces, thereby enabling the early detection and resolution of potential conflicts. The key approach is to unobtrusively inform developers of potential conflicts arising because of concurrent changes to the same file and dependency violations in ongoing parallel work. This paper describes our research goals, approach, and implementation of workspace awareness through Palantır and includes a comprehensive evaluation involving two laboratory experiments. We present both quantitative …


The Pricing Model Of Cloud Computing Services, Jianhui Huang, Dan Ma Aug 2012

The Pricing Model Of Cloud Computing Services, Jianhui Huang, Dan Ma

Research Collection School Of Computing and Information Systems

Cloud computing service providers offer computing resource as a utility and software as a service over network. Many believe that Cloud computing is making an industry-wise paradigm shift for IT use. Besides its technique issues, the business feature of Cloud computing attracts our interests. Specifically the practice of Amazon EC2 introduces an interesting pricing scheme. Amazon provides users with virtual computing instances as a combination of interruptible service (i.e., spot instance) and uninterruptible service (i.e., on-demand and reserved instance). Spot instance is charged at a per use price which is dynamically changing over time; users of spot instance face the …


A Survey Of Classical And Recent Results In Bin Packing Problem, Yoga Jaideep Darapuneni Aug 2012

A Survey Of Classical And Recent Results In Bin Packing Problem, Yoga Jaideep Darapuneni

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the classical bin packing problem one receives a sequence of n items 1, 2,..., n with sizes s1, s2, . . . ,sn where each item has a fixed size in (0, 1]. One needs to find a partition of the items into sets of size1, called bins, so that the number of sets in the partition is minimized and the sum of the sizes of the pieces assigned to any bin does not exceed its capacity. This combinatorial optimization problem which is NP hard has many variants as well as online and offline versions of the problem. Though …


Message Passing Algorithm For Different Problems Sum, Mean, Guide And Sorting In A Rooted Tree Network., Sabaresh Nageswara Rao Maddula Aug 2012

Message Passing Algorithm For Different Problems Sum, Mean, Guide And Sorting In A Rooted Tree Network., Sabaresh Nageswara Rao Maddula

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we give message passing algorithms in distributed environment for five different problems of a rooted tree having n nodes. In the first algorithm, every node has a value; the root calculates the sum of those values, and sends it to all the nodes in the network. In the second algorithm, the root computes the value of mean of values of all the nodes, and sends it to all nodes of the network. The third algorithm calculates the guide pairs. Guide pair of a node x is an ordered pair (pre_index(x), post_index(x)), where pre_index(x) and post_index(x) are the …


Image Processing With Cuda, Jia Jun Tse Aug 2012

Image Processing With Cuda, Jia Jun Tse

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis puts to the test the power of parallel computing on the GPU against the massive computations needed in image processing of large images. The GPU has long been used to accelerate 3D applications. With the advent of high level programmable interfaces, programming to the GPU is simplied and is being used to accelerate a wider class of applications. More specically, this thesis focuses on CUDA as its parallel programming platform.

This thesis explores on the possible performance gains that can be achieved by using CUDA on image processing. Two well known algorithms for image blurring and edge detection …


Post Processing Of Optically Recognized Text Via Second Order Hidden Markov Model, Srijana Poudel Aug 2012

Post Processing Of Optically Recognized Text Via Second Order Hidden Markov Model, Srijana Poudel

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we describe a postprocessing system on Optical Character Recognition(OCR) generated text. Second Order Hidden Markov Model (HMM) approach is used to detect and correct the OCR related errors. The reason for choosing the 2nd order HMM is to keep track of the bigrams so that the model can represent the system more accurately. Based on experiments with training data of 159,733 characters and testing of 5,688 characters, the model was able to correct 43.38 % of the errors with a precision of 75.34 %. However, the precision value indicates that the model

introduced some new errors, decreasing …


Dynamic Diffusion For Congestion Avoidance In Wireless Sensor Networks, Sri Divya Deenadayalan Aug 2012

Dynamic Diffusion For Congestion Avoidance In Wireless Sensor Networks, Sri Divya Deenadayalan

Boise State University Theses and Dissertations

Wireless Sensor Networks (WSNs) are employed for either continuous monitoring or event detection in the target area of interest. In event-driven applications, it is critical to report the detected events in the area, and with sudden bursts of traffic possible due to spatially-correlated events or multiple events, the data loss due to congestion will result in information loss or delayed arrival of the sensed information. Congestion control techniques detect congestion and attempt to recover from packet losses due to congestion, but they cannot eliminate or prevent the occurrence of congestion. Congestion avoidance techniques employ proactive measures to alleviate future congestion …