Physical Sciences and Mathematics Commons^™

New Estimators Of A Circular Median, Sauwanit Ratanaruamkarn

Dissertations

The specific properties of probability distributions on a circle require different definitions of several statistical concepts. For example, a median that can always be found for linear data not always exists on the circle. Several estimators of a circular median were proposed, lately by Otieno (2002), Otieno and Anderson - Cook (2003). Their work is, however, focused on the "preferred direction" which coincides with the median, mean and mode in the case of symmetric, unimodal distributions. This dissertation is focused on the estimators of a population median in a wider range of population distributions on a circle including distributions with …

Localization In Wireless Sensor Networks, Mark Terwilliger

Dissertations

With the proliferation of wireless sensor networks, providing location-aware technology and services to new applications have become important for developers. Localization is the problem of determining the positions of nodes in an ad hoc network. With the constrained resources of network sensors, providing robust localization services remains a fundamental research challenge facing the entire sensor network development community.

The initial localization problem that we addressed was to design and develop a working system that could locate equipment, such as a laptop or video projector. Ferret, the localization system developed, uses two different ranging techniques to help locate an object to …

Characterization And Quantum Efficiency Validation Of Ingaas Linear Focal Plane Array, Christopher Salenga Garcia

Electrical & Computer Engineering Theses & Dissertations

A 1x1024 InGaAs linear hybrid focal plane array (FPA) with CMOS readout was characterized at room temperature to analyze its electrical and optical properties and to measure its performance parameters.

The most important parameter of an FPA is the gain constant K, which allows conversion of the FPA output measurement unit from digital counts into the number of generated signal electrons. For FPAs with CMOS readout, the commonly used meanvariance method for determining K often underestimates its value. A more reliable method for finding K is the photon transfer technique, which is developed for FPAs with CCD readout. This …

A Multilane Pipelined Architecture For Real Time Enhancement Of Color Video Streams, Adam Redd Livingston

Electrical & Computer Engineering Theses & Dissertations

Video stream enhancement is a key fixture in a wide variety of applications from video surveillance, automatic navigation, medical imagery, to facial/object recognition systems. When a video stream contains non-uniform lighting it can be difficult to obtain what is in the darker regions without over enhancing brighter regions. The Adaptive and Integrated Neighborhood Dependant Approach for Nonlinear Enhancement (AINDANE) algorithm combines a tunable nonlinear transfer function, convolution by a multi-scale Gaussian kernel, and tunable contrast enhancement to address this problem for a single image. Luminance values are tuned based on the global cumulative distribution function (CDF) of an image. Contrast …

Mobius: An Omnidirectional Robotic Platform And Software Architecture For Network Teleoperation, Samuel Aaron Miller

Electrical & Computer Engineering Theses & Dissertations

The following thesis presents the results of a project to develop and test an omnidirectional robotic system (hardware and software) at NASA Langley Research Center's Robotics and Intelligent Machines Lab. The impetus for the project was the unique capabilities of omnidirectional systems. Some of the many potential benefits these systems have include improved material-handling capabilities in constrained environments (such as might be found in extraterrestrial manned habitats), efficient camera-based vehicle teleoperation, and simplified route planning for autonomous robot operations.

The project's focus was to design, build, and test a system that used Mecanum wheels to achieve omnidirectional motion. In addition …

Tuqr: A Topology Unaware Qos Routing Protocol For Manets, Ibrahim Zagli

Electrical & Computer Engineering Theses & Dissertations

In this thesis, the main purpose is to design a new Quality of Service (QoS) Routing Protocol for Mobile ad-hoc Networks that improves packet delivery ratio in QoS constrained communication in comparison to current well known protocols by using distributed multi-path routing. To accomplish that, a new approach to the QoS routing in Mobile ad hoc Networks (MANET) is developed to reduce the effects of the distrustful environment of MANET by keeping a number of suitable paths as high as possible and distributing the decision mechanism among the nodes on the path.

In most current protocols that mainly evaluate and …

Reversing Ticket Based Probing (Rtbp) Routing For Manet, Turgut Yucel

Electrical & Computer Engineering Theses & Dissertations

The delay-constrained maximum-bandwidth routing problem in MANET (Mobile Ad hoc Networks) is to find the maximum bandwidth path which satisfies a given delay constraint. The research challenge for this problem is that the networking information used for routing may be imprecise. The Ticket-Based Probing (TBP) routing algorithm provides a heuristic approach by using two types of ticket. In this thesis a Reversing Ticket-based Probing (RTBP) routing algorithm is proposed. The RTBP has two novel features compared to the original ticket based probing algorithms. The first feature is using just one type ticket, instead of two types of ticket. RTBP generates …

Whole Word Phonetic Displays For Speech Articulation Training, Fansheng Meng

Electrical & Computer Engineering Theses & Dissertations

The main objective of this dissertation is to investigate and develop speech recognition technologies for speech training for people with hearing impairments. During the course of this work, a computer aided speech training system for articulation speech training was also designed and implemented. The speech training system places emphasis on displays to improve children's pronunciation of isolated Consonant-Vowel-Consonant (CVC) words, with displays at both the phonetic level and whole word level. This dissertation presents two hybrid methods for combining Hidden Markov Models (HMMs) and Neural Networks (NNs) for speech recognition. The first method uses NN outputs as posterior probability estimators …

A Non-Linear Technique For The Enhancement Of Extremely Non-Uniform Lighting Images, Ender Oguslu

Electrical & Computer Engineering Theses & Dissertations

At night scenes, either the low intensity areas that are under poor light or the high intensity areas that are overexposed cannot be clearly seen. Various image processing techniques have been developed to recover the meaningful information under extremely low lighting conditions. Among these, the algorithms based on integrated neighborhood dependency of pixel characteristics and based on the illuminance reflectance model perform well for improving the visual quality of digital images captured under nonuniform and extremely low lighting conditions. Although these techniques perform well in low lighting conditions, they cannot perform well in overexposed regions under dark environments such as …

The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar

Electrical & Computer Engineering Theses & Dissertations

The wireless computer networks have an uncertainty in their structures aside from their big advantages for the users. The environmental conditions, changing locations of the mobile hosts and the changing components in the system can easily affect their reliability. In order to know a system capability performing its functions, keep the reliability at a certain level and/or detect the deficiency of the system, it is necessary to analyze the reliability of a computer communication network including the wired and wireless parts. But the above reasons also make the analysis and a unique solution difficult so a set of algorithms is …

Is There A Northern Lesser Antilles Forearc Block?, A. M. Lopez, S. Stein, Timothy H. Dixon, G. Sella, E. Calais, P. Jansma, J. Weber, P. Lafemina

School of Geosciences Faculty and Staff Publications

A systematic discrepancy exists between slip vectors of thrust fault earthquakes at the Lesser Antilles trench (LAT) and the predicted direction of North American‐Caribbean convergence. A possibility has been that the discrepancy resulted because neither was well constrained. Estimating Caribbean motion has been challenging owing to the limited data along the plate's complex boundaries. Similarly, earlier studies had few slip vectors because interplate thrust events are infrequent. To address these difficulties, we estimate a new Caribbean‐North America Euler vector using recently available GPS data from sites in the presumably stable interior of the Caribbean, and compare the predicted velocities to …

Realizing The Open-Closed Principle, Chong-Wei Xu, Jose Hughes

Faculty Articles

The first principle in developing large software systems is the open-closed principle (OCP). This principle seems asking for two conflict goals. How to realize the principle in the real software practice? What are the enabling technologies that can be used to implement the principle? This paper uses a case study to demonstrate the importance of the principle, the design methodology for realizing the principle, and its enabling technologies.

Tomographic Approach To Resolving The Distribution Of Lisa Galactic Binaries, Soumya Mohanty, Rajesh K. Nayak

Physics and Astronomy Faculty Publications and Presentations

The space based gravitational wave detector LISA (Laser Interferometer Space Antenna) is expected to observe a large population of Galactic white dwarf binaries whose collective signal is likely to dominate instrumental noise at observational frequencies in the range 10−4 to 10−3  Hz. The motion of LISA modulates the signal of each binary in both frequency and amplitude—the exact modulation depending on the source direction and frequency. Starting with the observed response of one LISA interferometer and assuming only Doppler modulation due to the orbital motion of LISA, we show how the distribution of the entire binary population in frequency and …

Dial 2004 Working Group Report On Acquisition Quality Control, William A. Barrett, Henry Baird, Frank Le Bourgeois, Xiaofan Lin, George Nagy, Steve Simske, Elisa H. Barney Smith

Faculty Publications

This report summarizes the discussions of the Working Group on Acquisition Quality at the International Workshop on Document Image Analysis for Libraries, Palo Alto, CA, 23-24 January 2004. Acquisition of the image is one of the most time intensive components of forming a digital library, and the quality of the acquisition will affect all later stages of the digital library project. The current state of the art in acquisition is analyzed. Problems and suggested improvements for image acquisition and storage formats and the special problems associated with acquisition from microfilm follows. A list of general suggestions was developed which was …

Separating Lines Of Text In Free-Form Handwritten Historical Documents, William A. Barrett, Douglas J. Kennard

Faculty Publications

We present an approach to finding (and separating) lines of text in free-form handwritten historical document images. After preprocessing, our method uses the count of foreground/background transitions in a binarized image to determine areas of the document that are likely to be text lines. Alternatively, an Adaptive Local Connectivity Map (ALCM) found in the literature can be used for this step of the process. We then use a min-cut/max-flow graph cut algorithm to split up text areas that appear to encompass more than one line of text. After removing text lines containing relatively little text information (or merging them with …

Crawdad: A Community Resource For Archiving Wireless Data At Dartmouth, Jihwang Yeo, David Kotz, Tristan Henderson

Dartmouth Scholarship

Wireless network researchers are seriously starved for data about how real users, applications, and devices use real networks under real network conditions. CRAWDAD, a Community Resource for Archiving Wireless Data at Dartmouth, is a new NSF-funded project to build a wireless network data archive for the research community. We host wireless data, and provide tools and documents to make it easy to collect and use wireless network data. We hope that this resource will help researchers identify and evaluate real and interesting problems in mobile and pervasive computing. This report outlines the CRAWDAD project, the kick-off workshop that was held …

Predictability Of Wlan Mobility And Its Effects On Bandwidth Provisioning, Libo Song, Udayan Deshpande, Ulaş C. Kozat, David Kotz, Ravi Jain

Dartmouth Scholarship

Wireless local area networks (WLANs) are emerging as a popular technology for access to the Internet and enterprise networks. In the long term, the success of WLANs depends on services that support mobile network clients. \par Although other researchers have explored mobility prediction in hypothetical scenarios, evaluating their predictors analytically or with synthetic data, few studies have been able to evaluate their predictors with real user mobility data. As a first step towards filling this fundamental gap, we work with a large data set collected from the Dartmouth College campus-wide wireless network that hosts more than 500 access points and …

Channel Sampling Strategies For Monitoring Wireless Networks, Udayan Deshpande, Tristan Henderson, David Kotz

Dartmouth Scholarship

Monitoring the activity on an IEEE 802.11 network is useful for many applications, such as network management, optimizing deployment, or detecting network attacks. Deploying wireless sniffers to monitor every access point in an enterprise network, however, may be expensive or impractical. Moreover, some applications may require the deployment of multiple sniffers to monitor the numerous channels in an 802.11 network. In this paper, we explore sampling strategies for monitoring multiple channels in 802.11b/g networks. We describe a simple sampling strategy, where each channel is observed for an equal, predetermined length of time, and consider applications where such a strategy might …

Extracting A Mobility Model From Real User Traces, Minkyong Kim, David Kotz, Songkuk Kim

Dartmouth Scholarship

Understanding user mobility is critical for simulations of mobile devices in a wireless network, but current mobility models often do not reflect real user movements. In this paper, we provide a foundation for such work by exploring mobility characteristics in traces of mobile users. We present a method to estimate the physical location of users from a large trace of mobile devices associating with access points in a wireless network. Using this method, we extracted tracks of always-on Wi-Fi devices from a 13-month trace. We discovered that the speed and pause time each follow a log-normal distribution and that the …

The Eclipsing Binary V1061 Cygni: Confronting Stellar Evolution Models For Active And Inactive Solar-Type Stars, Guillermo Torres, Claud H. Lacy, L. A. Marshall, Holly A. Sheets, Jeff A. Mader

Dartmouth Scholarship

We present spectroscopic and photometric observations of the eclipsing system V1061 Cyg (P = 2.35 days). A third star is visible in the spectrum, and the system is a hierarchical triple. We combine the radial velocities for the three stars, times of eclipse, and intermediate astrometric data from the Hipparcos mission (abscissa residuals) to establish the elements of the outer orbit, which is eccentric and has a period of 15.8 yr. We determine accurate values for the masses, radii, and effective temperatures of the binary components: M_Aa = 1.282 ± 0.015 M_☉, R_Aa = 1.615 …

A Knight’S Tour For All Rectangular Boards With Minimum Square Removal, Joe Demaio

Joe DeMaio

Velocity Imaging For The Liquid–Gas Interface In The Near Field Of An Atomizing Spray: Proof Of Concept, David L. Sedarsky, Megan E. Paciaroni, Mark A. Linne, James R. Gord, Terrence R. Meyer

Terrence R Meyer

We describe adaptation of ballistic imaging for the liquid core of an atomizing spray. To describe unambiguously the forces that act to break apart the liquid core in a spray, one must directly measure the force vectors themselves. It would be invaluable, therefore, to obtain velocity and acceleration data at the liquid-gas interface. We employ double-image ballistic imaging to extract velocity information through the application of image analysis algorithms. This method is shown to be effective for liquid phase droplet features within the resolution limit of the imaging system. In light of these results, it is clear that a three- …

Nonlinear Evolution Of The Plasma Beat Wave: Compressing The Laser Beat Notes Via Electromagnetic Cascading, Serguei Y. Kalmykov, Gennady Shvets

Serge Youri Kalmykov

The near-resonant beat wave excitation of an electron plasma wave (EPW) can be employed for generating the trains of few-femtosecond electromagnetic (EM) pulses in rarefied plasmas. The EPW produces a comoving index grating that induces a laser phase modulation at the difference frequency. As a result, the cascade of sidebands red and blue shifted by integer multiples of the beat frequency is generated in the laser spectrum. The bandwidth of the phase-modulated laser is proportional to the product of the plasma length, laser wavelength, and amplitude of the electron density perturbation. When the beat frequency is lower than the electron …

A Science Management Office For The U. S. Component Of The International Trans Antarctic Expedition (Us Itase Smo)Ûa Collaborative Pgrm Of Research From S. Pole To N. Victoria Land, Paul A. Mayewski, Gordon S. Hamilton

University of Maine Office of Research Administration: Grant Reports

This award supports a science management office for a pilot ice-core drilling and analysis program to test the feasibility of obtaining well-dated, high-resolution isotope and chemistry records from East Antarctica. Shallow ice cores will be obtained from two locations: 1) ~100 km from South Pole towards the Pole of Inaccessibility, as an extension of the Byrd Station-to-South Pole ITASE traverse [International Trans Antarctic Scientific Expedition]; 2) at Taylor Dome, near the original deep coring site, and (3) possibly at AGO 3 and AGO 4 as part of a logistics traverse to these sites. All of the cores collected will be …

Distinguishing Between Dirac And Majorana Neutrinos With Two-Particle Interferometry, T. Gutierrez

Physics

Two-particle interferometry, a second-order interference effect, is explored as another possible tool to distinguish between massive Dirac and Majorana neutrinos. A simple theoretical framework is discussed in the context of several gedanken experiments. The method can in principle provide both the mass scale and the quantum nature of the neutrino for a certain class of incoherent left-handed source currents.

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead-Alloys Coolant Systems: Quarterly Progress Report (01/01/06- 03/31/06), Yitung Chen

Transmutation Sciences Materials (TRP)

Research highlights:

• A cellular automaton model using method of global restructuring on the growth and corrosion during the formation of the passive layer has been developed.

• A stochastic model, which combines the surface growth and internal oxidation, has been developed to explain the oxidation mechanism of steels in liquid lead alloys.

• Two conference papers have been accepted and will be presented in 2006 International Congress on the Advances in Nuclear Power Plants (ICAPP '06).

Determining The Level Of Network Security Awareness Of Utc Students Living On Campus, Alma Cemerlic

Honors Theses

While information technology divisions in various schools often conduct surveys on general computer use, almost no studies have been done that directly targeted the level of Internet security awareness among college students. The National Cyber Security Alliance (NCSA), a not-for-profit, public-private partnership focused on increasing online security awareness, in collaboration with the Government and the Internet industry, organized a number of different projects designed to promote "safe online practices" among college students. However, since research has not been done to investigate the relationship between students' demographics and their Internet security awareness, it is not possible to tell how effective these …

Interagency Science And Research: Quarterly Progress Report, Period Ending March 31, 2006, Margaret N. Rees

Interagency Science and Research Strategy

• Interim (Phase I) Science and Research Strategy under development, with target
  completion by early May 2006.
• Interagency Science and Research Team meetings conducted approximately every two weeks
• Team extensively reviewed and approved plans, invitees, and timeline for two
  Ecosystem Health Assessment (Vital Signs) workshops scheduled for May and
  August 2006.

Lake Mead National Recreation Area Sensitive Wildlife Species Monitoring And Analysis: Quarterly Progress Report, Period Ending March 31, 2006, Margaret N. Rees

Wildlife Monitoring

• Research Assistant Professor hired to oversee NPS wildlife monitoring programs and serve as overall program coordinator for UNLV monitoring programs at Lake Mead National Recreation Area.
• Final report completed for 2004-2005 desert tortoise monitoring project.
• Final report completed for 2004-2005 relict leopard frog management.
• Recommendations for vegetation management research to improve relict leopard frog habitats at North Shore springs made to NPS Management Team
• Breeding surveys for relict leopard frog and egg collections for head-starting program completed.
• Final report completed of 2004-2005 monitoring efforts on peregrine falcons.
• Final report completed on 2004-2005 bald eagle monitoring.
• Bald eagle survey for 2006 …

Take Pride In America In Southern Nevada: Quarterly Progress Report, Period Ending March 31, 2006, Margaret N. Rees

Anti-littering Programs

• A community-based roundtable met three times this quarter to suggest goals and objectives for the anti-litter strategic plan.

• Project Manager Doug Joslin is representing the public lands on a Clark County Recycling Advisory Committee, which met twice this quarter.

• Four public service announcements were produced by UNLV students, with one selected by the team for use in the Southern Nevada messaging campaign.

• The Clint Eastwood Take Pride in America PSA aired 74 times in January 2006 and was viewed by 116,802 people.

• The interagency team has begun arrangements for paper recycling in partnership with the …