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University of Nebraska - Lincoln

2011

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Articles 1 - 30 of 68

Full-Text Articles in Computer Engineering

A Study Of Correlations Between The Definition And Application Of The Gene Ontology, Yuji Mo Dec 2011

A Study Of Correlations Between The Definition And Application Of The Gene Ontology, Yuji Mo

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

When using the Gene Ontology (GO), nucleotide and amino acid sequences are annotated by terms in a structured and controlled vocabulary organized into relational graphs. The usage of the vocabulary (GO terms) in the annotation of these sequences may diverge from the relations defined in the ontology. We measure the consistency of the use of GO terms by comparing GO's defined structure to the terms' application. To do this, we first use synthetic data with different characteristics to understand how these characteristics influence the correlation values determined by various similarity measures. Using these results as a baseline, we found that …


A General Attack Method For Steganography Removal Using Pseudo-Cfa Re-Interpolation, Pradhumna Shrestha, Michael Hempel, Tao Ma, Dongming Peng, Hamid Sharif Dec 2011

A General Attack Method For Steganography Removal Using Pseudo-Cfa Re-Interpolation, Pradhumna Shrestha, Michael Hempel, Tao Ma, Dongming Peng, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Watermarking and steganography are two of the most researched topics in multimedia forensics. However, easy availability of tools and technology has made their misuse a serious concern. To counteract this development some effective tools are necessary to remove malicious steganography. In this work, we introduce a novel watermark attack method which can destroy hidden information embedded in images based on the principle of re-interpolation of Color Filter Array (CFA) artifacts. In digital cameras and scanners, CFA filters are used to acquire low-resolution physical color channel information and produce a high-quality image by subsequent interpolation. We propose to emulate a similar …


A Novel Telecommunications-Based Approach To Mathematical Modeling Of Hiv Infection, Aaron T. Sharp Dec 2011

A Novel Telecommunications-Based Approach To Mathematical Modeling Of Hiv Infection, Aaron T. Sharp

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

It is well known that biological systems utilize communication in some form, one prolific example of this is the propagation of HIV (Human Immunodeficiency Virus) in the human body. By modeling HIV infection as a communication system, we hope to gain a unique insight into HIV and biological communication systems in general. Such a model would provide researchers a platform for experimenting and simulating various biological communication systems. We have previously developed a layered communication protocol for interpreting biological communication systems using telecommunications paradigms and will apply said model to HIV proliferation. We will also demonstrate the effectiveness of the …


Location Cheating: A Security Challenge To Location-Based Social Network Services, Mai Ren Dec 2011

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

Department of Computer Science and Engineering: 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 …


Relational Neighborhood Inverse Consistency For Constraint Satisfaction: A Structure-Based Approach For Adjusting Consistency & Managing Propagation, Robert J. Woodward Dec 2011

Relational Neighborhood Inverse Consistency For Constraint Satisfaction: A Structure-Based Approach For Adjusting Consistency & Managing Propagation, Robert J. Woodward

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Freuder and Elfe [1996] introduced Neighborhood Inverse Consistency (NIC) as a local consistency property defined on the values in the variables' domains of a Constraint Satisfaction Problem (CSP). Debruyne and Bessiere [2011] showed that enforcing NIC on binary CSPs is ineffective on sparse graph and too costly on dense graphs. In this thesis, we propose Relational Neighborhood Inverse Consistency (RNIC), an extension of NIC defined as a local consistency property on the tuples of the relations of a CSP. We characterize RNIC for both binary and non-binary CSPs, and propose an algorithm for enforcing it whose complexity is bounded by …


A Quantitative Performance Analysis Of 2.5 Ghz And 3.65 Ghz Mobile Wimax, Pradhumna L. Shrestha Nov 2011

A Quantitative Performance Analysis Of 2.5 Ghz And 3.65 Ghz Mobile Wimax, Pradhumna L. Shrestha

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

Mobile WiMAX has emerged as a prime contender for the de-facto ITU’s 4G standard. It provides high data rate with large coverage and vehicular mobility support. It has been, and is being, widely deployed in diverse applications like video streaming, broadcasting and data service. The FCC (Federal Communications Commission) issues licenses to operate Mobile WiMAX services in several spectrums, among which 2.5 GHz and 3.65 GHz are the most common. Because the 2.5 GHz spectrum suffers the least propagation losses, it has been widely applied commercially. For this reason, academic and industrial researchers have given it particular attention. However, in …


Efficient Traffic Crash And Snow Complaint Gis System, Anthony B. Ngo Nov 2011

Efficient Traffic Crash And Snow Complaint Gis System, Anthony B. Ngo

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

We describe the design and implementation of a traffic crash and snow complaint GIS system developed for the Lincoln Public Works department. We also describe a novel geocoding algorithm that was used to move data from the older Criminal Justice Information System, which is a relational database, to the new GIS system. In addition, we describe the implementation of several indexing algorithms that enable the system to efficiently answer rectangular range queries and queries about the relative locations of moving objects. Finally, in many applications (on-line analysis or mobile GIS), we need to execute spatial query efficiently (fast and small), …


A Cross-Layer Design For The Performance Improvement Of Real-Time Video Transmission Of Secondary Users Over Cognitive Radio Networks, Haiyan Luo, Song Ci, Dalei Wu Aug 2011

A Cross-Layer Design For The Performance Improvement Of Real-Time Video Transmission Of Secondary Users Over Cognitive Radio Networks, Haiyan Luo, Song Ci, Dalei Wu

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Cognitive radio (CR) has been proposed as a promising solution to improve connectivity, self-adaptability, and efficiency of spectrum usage. When used in video applications, user-perceived video quality experienced by secondary users is a very important performance metric to evaluate the effectiveness of CR technologies. However, most of the current research only considers spectrum utilization and effectiveness at medium access control (MAC) and physical layers, ignoring the system performance of the upper layers. Therefore, in this paper, we aim to improve the user experience of secondary users for wireless video services over CR networks. We propose a quality-driven cross-layer optimized system …


Classification For Mass Spectra And Comprehensive Two-Dimensional Chromatograms, Xue Tian Aug 2011

Classification For Mass Spectra And Comprehensive Two-Dimensional Chromatograms, Xue Tian

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Mass spectra contain characteristic information regarding the molecular structure and properties of compounds. The mass spectra of compounds from the same chemically related group are similar. Classification is one of the fundamental methodologies for analyzing mass spectral data. The primary goals of classification are to automatically group compounds based on their mass spectra, to find correlation between the properties of compounds and their mass spectra, and to provide a positive identification of unknown compounds.

This dissertation presents a new algorithm for the classification of mass spectra, the most similar neighbor with a probability-based spectrum similarity measure (MSN-PSSM). Experimental results demonstrate …


Wireless Embedded Smart Cameras: Performance Analysis And Their Application To Fall Detection For Eldercare., Alvaro Pinto Jul 2011

Wireless Embedded Smart Cameras: Performance Analysis And Their Application To Fall Detection For Eldercare., Alvaro Pinto

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Wireless Embedded Smart Camera Networks has received a lot of attention from academia and industry because they are small in size and easy to deploy, and they offer a multitude of attractive applications. They can be used for embedded single unit applications, or can be networked for multi-camera applications.

We first analyze three different operation scenarios for a wireless vision sensor network wherein different levels of local processing is performed. A detailed quantitative comparison of three operation scenarios are presented in terms of energy consumption and latency. This quantitative analysis provides the motivation for performing high-level local processing and decision …


Molecular Dynamics Simulation Based On Hadoop Mapreduce, Chen He Jul 2011

Molecular Dynamics Simulation Based On Hadoop Mapreduce, Chen He

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Molecular Dynamics (MD) simulation is a computationally intensive application used in multiple fields. It can exploit a distributed environment due to inherent computational parallelism. However, most of the existing implementations focus on performance enhancement. They may not provide fault-tolerance for every time-step.

MapReduce is a framework first proposed by Google for processing huge amounts of data in a distributed environment. The simplicity of the programming model and fault- tolerance for node failure during run-time make it very popular not only for commercial applications but also in scientific computing.

In this thesis, we develop a novel communication-free and each time-step fault- …


Real-Time Divisible Load Scheduling For Cluster Computing, Anwar Mamat Jul 2011

Real-Time Divisible Load Scheduling For Cluster Computing, Anwar Mamat

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Cluster computing has become an important paradigm for solving large-scale problems. However, as the size of a cluster increases, so does the complexity of resource management and maintenance. Therefore, automated performance control and re- source management are expected to play critical roles in sustaining the evolution of cluster computing. The current cluster scheduling practice is similar in sophistication to early supercomputer batch scheduling algorithms, and no consideration is given to desired quality-of-service (QoS) attributes. To fully avail the power of computational clusters, new scheduling algorithms that provides high performance, QoS assurance, fault-tolerance, energy savings and streamlined management of the cluster …


Enhancement Of Optical Emission From Laser-Induced Plasmas By Combined Spatial And Magnetic Confinement, L. B. Guo, W. Hu, B. Y. Zhang, X. N. He, C. M. Li, Y. S. Zhou, Z. X. Cai, X. Y. Zeng, Yongfeng Lu Jul 2011

Enhancement Of Optical Emission From Laser-Induced Plasmas By Combined Spatial And Magnetic Confinement, L. B. Guo, W. Hu, B. Y. Zhang, X. N. He, C. M. Li, Y. S. Zhou, Z. X. Cai, X. Y. Zeng, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Within the past decades, laser-induced breakdown spectroscopy (LIBS) has become a well-established and powerful optical emission spectroscopy (OES) analytical technique [1–5]. As a useful analytical tool, LIBS is used extensively in various areas such as remote detection, hostile environment monitoring, and cultural heritage conservation [6–10]. Researchers are paying more attention to LIBS as a diagnostic method for elemental analysis as it is characterized by fast, real-time, in situ, low invasiveness, and multi-elemental diagnosis, normally without the need for sample preparation [11,12]. However, one of its major drawbacks is its low sensitivity, which seriously hinders further improving the limit of detection …


Apparatus For Dispensing Material, Peter Werner Sutter, Eli Anguelova Sutter Jul 2011

Apparatus For Dispensing Material, Peter Werner Sutter, Eli Anguelova Sutter

Department of Electrical and Computer Engineering: Faculty Publications

An apparatus capable of dispensing drops of material with volumes on the order of Zeptoliters is described. In some embodiments of the inventive pipette the size of the droplets so dispensed is determined by the size of a hole, or channel, through a carbon shell encapsulating a reservoir that contains material to be dispensed. The channel may be formed by irradiation with an electronbeam or other high-energy beam capable of focusing to a spot size less than about 5 nanom eters. In some embodiments, the dispensed droplet remains attached to the pipette by a small thread of material, an atomic …


Quantifying Performance Of Cooperative Diversity Using The Sampling Property Of A Delta Function, Won Mee Jang Jul 2011

Quantifying Performance Of Cooperative Diversity Using The Sampling Property Of A Delta Function, Won Mee Jang

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In this paper, we present a simple approach to evaluating the performance of amplify-and-forward cooperative diversity. The �-function can be asymptotically reduced to a delta (impulse) function. We extend the result to cooperative networks in fading channels. The proposed approach introduces a simple technique to evaluate the performance of complex networks by sampling.


A Reservation-Based Smart Parking System, Hongwei Wang Jul 2011

A Reservation-Based Smart Parking System, Hongwei Wang

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

In metropolitan areas, parking management influences drivers search time and cost for parking spaces, parking revenue, and traffic congestion. The wide deployment of wireless parking meters with sensing and communications capabilities allows the parking authority to monitor the state of each parking space in real time and optimize the parking management.

In this thesis, we study state-of-the-art parking policies in smart parking systems, and show that the smart parking system needs to be "smarter". Our design goals of the smart parking systems include: (1) simplify the operations of parking systems, (2) improve drivers' satisfaction, (3) increase parking revenue, and (4) …


A Study On Facility Planning Using Discrete Event Simulation: Case Study Of A Grain Delivery Terminal., Sarah M. Asio Jul 2011

A Study On Facility Planning Using Discrete Event Simulation: Case Study Of A Grain Delivery Terminal., Sarah M. Asio

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

The application of traditional approaches to the design of efficient facilities can be tedious and time consuming when uncertainty and a number of constraints exist. Queuing models and mathematical programming techniques are not able to capture the complex interaction between resources, the environment and space constraints for dynamic stochastic processes. In the following study discrete event simulation is applied to the facility planning process for a grain delivery terminal. The discrete event simulation approach has been applied to studies such as capacity planning and facility layout for a gasoline station and evaluating the resource requirements for a manufacturing facility. To …


Study Of Cellular Phone Detection Techniques, Nicholas W. Scott Jun 2011

Study Of Cellular Phone Detection Techniques, Nicholas W. Scott

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

This thesis studies techniques for detecting cellular phones. It examines existing technology currently available on the open market, an existing design that utilizes mostly discrete components, and a design approach using a down converter in conjunction with a bandpass filter.

The existing technologies available on the open market are examined and discussed. These technologies are not adequate, because they are inaccurate and expensive.

The first signal detection technique, an existing design utilizing discrete components is difficult to implement. They are very affordable to construct, but require precision tuning. This design is analyzed and found to be inaccurate.

The second signal …


Generation Of High-Temperature And Low-Density Plasmas For Improved Spectral Resolutions In Laser-Induced Breakdown Spectroscopy, X. N. He, W. Hu, C. M. Li, L. B. Guo, Yongfeng Lu May 2011

Generation Of High-Temperature And Low-Density Plasmas For Improved Spectral Resolutions In Laser-Induced Breakdown Spectroscopy, X. N. He, W. Hu, C. M. Li, L. B. Guo, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Improved spectral resolutions were achieved in laser-induced breakdown spectroscopy (LIBS) through generation of high-temperature and low-density plasmas. A first pulse from a KrF excimer laser was used to produce particles by perpendicularly irradiating targets in air. A second pulse from a 532 nm Nd:YAG laser was introduced parallel to the sample surface to reablate the particles. Optical scattering from the first-pulse plasmas was imaged to elucidate particle formation in the plasmas. Narrower line widths (full width at half maximums: FWHMs) and weaker self-absorption were observed from time-integrated LIBS spectra. Estimation of plasma temperatures and densities indicates that high temperature and …


Campus Grids: A Framework To Facilitate Resource Sharing, Derek J. Weitzel May 2011

Campus Grids: A Framework To Facilitate Resource Sharing, Derek J. Weitzel

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

It is common at research institutions to maintain multiple clusters. These might fulfill different needs and policies, or represent different owners or generations of hard- ware. Many of these clusters are under utilized while researchers at other departments may require these resources. This may be solved by linking clusters with grid mid- dleware. This thesis describes a distributed high throughput computing framework to link clusters without changing security or execution environments. The framework initially keeps jobs local to the submitter, overflowing if necessary to the campus, and regional grid. The framework is implemented spanning two campuses at the Holland Computing …


Exploration Of Spatial Diversity In Multi-Antenna Wireless Communication Systems, Shichuan Ma May 2011

Exploration Of Spatial Diversity In Multi-Antenna Wireless Communication Systems, Shichuan Ma

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

With increasing demand on wireless internet and personal multimedia, the data rate of wireless communications is expected to increase dramatically. Future wireless networks face challenges of supporting data rates higher than one gigabits per second. Among various technologies, multi-antennas, also known as multiple-input multiple-output (MIMO), are undoubtedly the most promising to enable higher data rates. By employing the extra degrees of freedom in the spatial domain, multi-antenna techniques enhance the wireless communication systems through array gain, spatial diversity, and spatial multiplexing. Although multi-antenna systems have been utilized for more than ten years, a thorough analysis of various aspects of multi-antenna …


Protein Structure – Based Method For Identification Of Horizontal Gene Transfer In Bacteria, Swetha Billa May 2011

Protein Structure – Based Method For Identification Of Horizontal Gene Transfer In Bacteria, Swetha Billa

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Horizontal Gene Transfer is defined as the movement of genetic material from one strain of species to another. Bacteria, being an asexual organism were always believed to transfer genes vertically. But recent studies provide evidence that shows bacteria can also transfer genes horizontally.

HGT plays a major role in evolution and medicine. It is the major contributor in bacterial evolution, enabling species to acquire genes to adapt to the new environments. Bacteria are also believed to develop drug resistance to antibiotics through the phenomenon of HGT. Therefore further study of HGT and its implications is necessary to understand the effects …


Ontology For Psychophysiological Dysregulation Of Anger/Aggression, Swathi Vasanthapuram May 2011

Ontology For Psychophysiological Dysregulation Of Anger/Aggression, Swathi Vasanthapuram

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

The advancement of Information Technology in the last four decades led to the use of computers in medicine. A new area called Medical Informatics has emerged. This area comprises the application of IT to healthcare with the aim of creating tools that help healthcare personnel diagnose and treat patients more accurately and efficiently. IT not only provides tools for storing, integrating, and updating patient information base but also for processing information efficiently. One of such tools is a Clinical Decision Support System. Ontologies are an integral part of clinical decision support systems because they help formalize and integrate domain knowledge. …


Understanding User Generated Content Characteristics : A Hot-Event Perspective, Miao Wang, Guodong Li, Jie Feng, Lisong Xu, Byrav Ramamurthy, Wei Li, Xiaohong Guan Apr 2011

Understanding User Generated Content Characteristics : A Hot-Event Perspective, Miao Wang, Guodong Li, Jie Feng, Lisong Xu, Byrav Ramamurthy, Wei Li, Xiaohong Guan

CSE Conference and Workshop Papers

Nowadays, millions of Internet users watch and upload a large number of videos on User Generated Content (UGC) sites (e.g., Youtube) everyday. Moreover, online videos about hot events, such as breaking news and Olympic games, attract lots of users. In this paper, we study the characteristics of hot-event videos by collecting video traces of the largest UGC site in China for 28 days. We first empirically study statistical properties of such videos and find that hot-event videos contribute a large number of views, even though the total number of hotevent videos is relatively small. In addition, there exist extremely active …


Using Textual Features To Predict Popular Content On Digg, Paul H. Miller Apr 2011

Using Textual Features To Predict Popular Content On Digg, Paul H. Miller

Department of English: Dissertations, Theses, and Student Research

Over the past few years, collaborative rating sites, such as Netflix, Digg and Stumble, have become increasingly prevalent sites for users to find trending content. I used various data mining techniques to study Digg, a social news site, to examine the influence of content on popularity. What influence does content have on popularity, and what influence does content have on users’ decisions? Overwhelmingly, prior studies have consistently shown that predicting popularity based on content is difficult and maybe even inherently impossible. The same submission can have multiple outcomes and content neither determines popularity, nor individual user decisions. My results show …


Optimized Delay-Sensitive Multimedia Communications Over Wireless Networks, Haiyan Luo Apr 2011

Optimized Delay-Sensitive Multimedia Communications Over Wireless Networks, Haiyan Luo

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

Multimedia communication is expected to be the major application of the next-generation wireless networks. However, providing delay-sensitive, loss-tolerant and resource-guzzling multimedia services over the current resource-limited wireless networks is still a very challenging task. In addition to their heterogeneous nature and resource limitation, wireless networks also suffer from channel variations and environmental changes. In this dissertation, we study the optimization techniques for wireless multimedia communications and address the issues from different theoretical and practical perspectives.

To solve the issues resulting from the increasingly heterogeneous wireless networks, we propose a framework for error resilient source coding and distributed application-layer error control, …


Multi-Channel Peer-To-Peer Streaming Systems As Resource Allocation Problems, Miao Wang Apr 2011

Multi-Channel Peer-To-Peer Streaming Systems As Resource Allocation Problems, Miao Wang

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

In the past few years, the Internet has witnessed the success of Peer-to-Peer (P2P) streaming technology, which has attracted millions of users. More recently, commercial P2P streaming systems have begun to support multiple channels and a user in such systems is allowed to watch more than one channel at a time. We refer to such systems as multi-channel P2P streaming systems. In this dissertation, we focus on designing multi-channel P2P streaming systems with the goal of providing optimal streaming quality for all channels, termed as system-wide optimal streaming quality. Specifically, we design the systems from the perspective of how to …


Offline Optimization Of Advance Reservation Of Bandwidth Over Dynamic Circuit Networks, Pragatheeswaran Angu Apr 2011

Offline Optimization Of Advance Reservation Of Bandwidth Over Dynamic Circuit Networks, Pragatheeswaran Angu

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

E-science projects require very high-speed and reliable networks to transfer data across various destinations in the world. Dynamic Circuit Network (DCN) is a networking service to make advance reservation of bandwidth between a source and a destination in a network. In this thesis we solve the problem of advance reservation of bandwidth in next-generation wavelength-division multiplexing (WDM) networks using a simulation based approach.
We implement a greedy algorithm and a genetic algorithm in parallel, in separate threads. The request for advance reservation is processed by both but the user gets the response only from the greedy algorithm. The genetic algorithm …


Polygonal Spatial Clustering, Deepti Joshi Apr 2011

Polygonal Spatial Clustering, Deepti Joshi

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Clustering, the process of grouping together similar objects, is a fundamental task in data mining to help perform knowledge discovery in large datasets. With the growing number of sensor networks, geospatial satellites, global positioning devices, and human networks tremendous amounts of spatio-temporal data that measure the state of the planet Earth are being collected every day. This large amount of spatio-temporal data has increased the need for efficient spatial data mining techniques. Furthermore, most of the anthropogenic objects in space are represented using polygons, for example – counties, census tracts, and watersheds. Therefore, it is important to develop data mining …


Propeller: A Scalable Metadata Organization For A Versatile Searchable File System, Lei Xu, Hong Jiang, Xue Liu, Lei Tian, Yu Hua, Jian Hu Mar 2011

Propeller: A Scalable Metadata Organization For A Versatile Searchable File System, Lei Xu, Hong Jiang, Xue Liu, Lei Tian, Yu Hua, Jian Hu

CSE Technical Reports

The exponentially increasing amount of data in file systems has made it increasingly important for users, administrators and applications to be able to fast retrieve files using file-search services, instead of replying on the standard file system API to traverse the hierarchical namespaces. The quality of the file-search services is significantly affected by the file-indexing overhead, the file-search performance and the accuracy of search results. Unfortunately, the existing file-search solutions either are so poorly scalable that their performance degrades unacceptably when the systems scale up, or incur so much crawling delays that they produce acceptably inaccurate results. We believe that …