Physical Sciences and Mathematics Commons^™

Is The Subdominant Part Of The Energy Spectrum Due To Downscale Energy Cascade Hidden In Quasi-Geostrophic Turbulence?, Eleftherios Gkioulekas, Ka Kit Tung

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In systems governing two-dimensional turbulence, surface quasi-geostrophic turbulence, (more generally $\alpha$-turbulence), two-layer quasi-geostrophic turbulence, etc., there often exist two conservative quadratic quantities, one "energy''-like and one "enstrophy''-like. In a finite inertial range there are in general two spectral fluxes, one associated with each conserved quantity. We derive here an inequality comparing the relative magnitudes of the "energy'' and "enstrophy'' fluxes for finite or infinitesimal dissipations, and for hyper or hypo viscosities. When this inequality is satisfied, as is the case of 2D turbulence,where the energy flux contribution to the energy spectrum is small, the subdominant part will be effectively hidden. …

Evaluating Recruitment Of American Eel, Anguilla Rostrata, To The Potomac River (Spring 2007), Hank Brooks, Wendy A. Lowery, Aimee Halvorson, James Gartland, Marcel M. Montane

Reports

Harvests of American eel along the U.S. Atlantic Coast have declined in recent years, and similar patterns have been noted in the Canadian Maritime Provinces as well as in Europe with its congener, A. anguilla (Ciccotti et al., 4 1995). Fishery independent indices of abundance have also shown a decline in American eel populations in recent years (Richkus and Whalen, 1999; Geer, 2003; Montane and Fabrizio, 2006). Possible explanations for this decline include Gulf Stream shifts, pollution, overfishing, parasites, and barriers to fish passage (Castonguay et al., 1994; Haro et al., 2000). In addition, local factors such as unfavorable wind-driven …

The Coastal Primary Sand Dune And Beach Act, Lyle M. Varnell, C. Scott Hardaway Jr.

Reports

This document presents the supporting information and justification for the following recommendations: • Adding Middlesex County and Westmoreland County to the list of localities authorized to adopt the model ordinance of the Coastal Primary Sand Dune and Beach Act (Title 28.2, Chapter 14 of the Virginia Code) would result in the inclusion of significant dune resources into Virginia’s tidal shoreline management program. • Adding the localities of Charles City, Essex, Gloucester, Isle of Wight, James City, King and Queen, King George, Middlesex, New Kent, Newport News, Prince George, Richmond (county), Stafford, Surry, Westmoreland, and York to the list of localities …

Globally Distributed Software Development Project Performance: An Empirical Analysis, Narayanasamy Ramasubbu, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

Software firms are increasingly distributing their software development effort across multiple locations. In this paper we present the results of a two year field study that investigated the effects of dispersion on the productivity and quality of distributed software development. We first develop a model of distributed software development. We then use the model, along with our empirically observed data, to understand the consequences of dispersion on software project performance. Our analysis reveals that, even in high process maturity environments, a) dispersion significantly reduces development productivity and has effects on conformance quality, and b) these negative effects of dispersion can …

Robust Local Search And Its Application To Generating Robust Schedules, Hoong Chuin Lau, Fei Xiao, Thomas Ou

Research Collection School Of Computing and Information Systems

In this paper, we propose an extended local search framework to solve combinatorial optimization problems with data uncertainty. Our approach represents a major departure from scenario-based or stochastic programming approaches often used to tackle uncertainty. Given a value 0 < ? 1, we are interested to know what the robust objective value is, i.e. the optimal value if we allow an chance of not meeting it, assuming that certain data values are defined on bounded random variables. We show how a standard local search or metaheuristic routine can be extended to efficiently construct a decision rule with such guarantee, albeit heuristically. We demonstrate its practical applicability on the Resource Constrained Project Scheduling Problem with minimal and maximal time lags (RCPSP/max) taking into consideration activity duration uncertainty. Experiments show that, partial order schedules can be constructed that are robust in our sense without the need for a large planned horizon (due date), which improves upon the work proposed by Policella et al. 2004.

Rushes Video Summarization By Object And Event Understanding, Feng Wang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper explores a variety of visual and audio analysis techniques in selecting the most representative video clips for rushes summarization at TRECVID 2007. These techniques include object detection, camera motion estimation, keypoint matching and tracking, audio classification and speech recognition. Our system is composed of two major steps. First, based on video structuring, we filter undesirable shots and minimize the inter-shot redundancy by repetitive shot detection. Second, a representability measure is proposed to model the presence of objects and four audio-visual events: motion activity of objects, camera motion, scene changes, and speech content, in a video clip. The video …

Stellar Populations Across The Ngc 4244 Truncated Galactic Disk., Roelof De Jong, A. C. Seth, D. Radburn-Smith, E. F. Bell, T. M. Brown, J. S. Bullock, S. Courteau, J. J. Dalcanton, H. C. Ferguson, P. Goudfrooij, S. Holfeltz, Benne W. Holwerda, C. Purcell, J. Sick, D. B. Zucker

Faculty and Staff Scholarship

We use the Hubble Space Telescope ACS to study the resolved stellar populations of the nearby, nearly edgeon galaxy NGC 4244 across its outer disk surface density break. The stellar photometry allows us to study the distribution of different stellar populations and reach very low equivalent surface brightnesses. We find that the break occurs at the same radius for young, intermediate-age, and old stars. The stellar density beyond the break drops sharply by a factor of at least 600 in 5 kpc. The break occurs at the same radius independent of height above the disk, but is sharpest in the …

Stellar Population Models And Individual Element Abundances. I. Sensitivity Of Stellar Evolution Models, Aaron Dotter, Brian Chaboyer, Jason W. Ferguson, Hyun-Chul Lee

Dartmouth Scholarship

Integrated light from distant galaxies is often compared to stellar population models via the equivalent widths of spectral features—spectral indices—whose strengths rely on the abundances of one or more elements. Such comparisons hinge not only on the overall metal abundance, but also on relative abundances. Studies have examined the influence of individual elements on synthetic spectra but little has been done to address similar issues in the stellar evolution models that underlie most stellar population models. Stellar evolution models will primarily be influenced by changes in opacities. In order to explore this issue in detail, 12 sets of stellar evolution …

Ntu: Solution For The Object Retrieval Task Of The Imageclef2007, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

Object retrieval is an interdisciplinary research problem between object recognition and content-based image retrieval (CBIR). It is commonly expected that object retrieval can be solved more effectively with the joint maximization of CBIR and object recognition techniques. We study a typical CBIR solution with application to the object retrieval tasks [26,27]. We expect that the empirical study in this work will serve as a baseline for future research when using CBIR techniques for object recognition.

Practical Elimination Of Near-Duplicates From Web Video Search, Xiao Wu, Alexander G. Hauptmann, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Current web video search results rely exclusively on text keywords or user-supplied tags. A search on typical popular video often returns many duplicate and near-duplicate videos in the top results. This paper outlines ways to cluster and filter out the nearduplicate video using a hierarchical approach. Initial triage is performed using fast signatures derived from color histograms. Only when a video cannot be clearly classified as novel or nearduplicate using global signatures, we apply a more expensive local feature based near-duplicate detection which provides very accurate duplicate analysis through more costly computation. The results of 24 queries in a data …

Ontology-Enriched Semantic Space For Video Search, Xiao-Yong Wei, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Multimedia-based ontology construction and reasoning have recently been recognized as two important issues in video search, particularly for bridging semantic gap. The lack of coincidence between low-level features and user expectation makes concept-based ontology reasoning an attractive midlevel framework for interpreting high-level semantics. In this paper, we propose a novel model, namely ontology-enriched semantic space (OSS), to provide a computable platform for modeling and reasoning concepts in a linear space. OSS enlightens the possibility of answering conceptual questions such as a high coverage of semantic space with minimal set of concepts, and the set of concepts to be developed for …

Context-Based Detection Of Clone-Related Bugs, Lingxiao Jiang, Zhendong Su, Edwin Chiu

Research Collection School Of Computing and Information Systems

Studies show that programs contain much similar code, commonly known as clones. One of the main reasons for introducing clones is programmers' tendency to copy and paste code to quickly duplicate functionality. We commonly believe that clones can make programs difficult to maintain and introduce subtle bugs. Although much research has proposed techniques for detecting and removing clones to improve software maintainability, little has considered how to detect latent bugs introduced by clones. In this paper, we introduce a general notion of context-based inconsistencies among clones and develop an efficient algorithm to detect such inconsistencies for locating bugs. We have …

Difference Computation Of Large Models, Christoph Treude, Stefan Berlik, Sven Wenzel, Udo Kelter

Research Collection School Of Computing and Information Systems

Modern software engineering practices lead to large models which exist in many versions. Version management systems should offer a service to compare, and possibly merge, these models. The computation of a difference between large models is a big challenge; current algorithms are too inefficient here. We present a new technique for computing differences between models. In practical tests, this technique has been an order of magnitude faster than currently known algorithms. The main idea is to use a high-dimensional search tree for efficiently finding similar model elements. Individual elements are mapped onto a vector of numerical values using a collection …

Stellar Population Models And Individual Element Abundances. I. Sensitivity Of Stellar Evolution Models, Aaron Dotter, Brian Chaboyer, Jason W. Ferguson, Hyun Chul Lee, Guy Worthey, Darko Jevremović, E. Baron

Physics and Astronomy Faculty Publications and Presentations

Integrated light from distant galaxies is often compared to stellar population models via the equivalent widths of spectral features-spectral indices-whose strengths rely on the abundances of one or more elements. Such comparisons hinge not only on the overall metal abundance, but also on relative abundances. Studies have examined the influence of individual elements on synthetic spectra but little has been done to address similar issues in the stellar evolution models that underlie most stellar population models. Stellar evolution models will primarily be influenced by changes in opacities. In order to explore this issue in detail, 12 sets of stellar evolution …

On The Time-Resolved Optogalvanic Spectra Of Neon And Krypton, Naveed Piracha, K. Nesbett, S. Moten, P. Moeller

Naveed K. Piracha

In this work time resolved optogalvanic signals associated with transitions excited from the first metastable state of neon and krypton have been studied. These gases have similar energy state configurations and it is of significant interest to study their time resolved optogalvanic waveforms resulting from transitions belonging to the states of same quantum numbers. The experimentally observed optogalvanic signals recorded for different discharge currents have been fitted to a theoretical model to obtain parameters that determine amplitudes, instrumental time constants and decay rates of the 1s levels.

Preliminary Model Tests For The Design Of A Gliding Deep Water Elevator, Christopher Roman, T. Gregory, E. Martin, A. Sanguinetti, J. Drummond

Christopher N. Roman

This paper presents progress on the design of a "smart elevator" to be used in conjunction with deep sea ROV operations. Deep sea elevators are gravity driven untethered platforms used to deliver and or return items from the sea floor. Elevators are used when items are too large or heavy to be handled by the ROV, or when the turn around time to recover and redeploy the ROV system for sample removal is prohibitive. Unfortunately, efficiency is complicated by the precision with which elevators can be landed at a specific location on the bottom and recovered on the surface because …

Mitigation Of Biases Using The Schmidt-Kalman Filter - Art. No. 66990q, Randy Paffenroth, Roman Novoselov, Scott Danford, Marcio Teixeira, Stephanie Chan, Aubrey Poore

Randy C. Paffenroth

Fusion of data from multiple sensors can be hindered by systematic bias errors. This may lead to severe degradation in data association and track quality and may result in a large growth of redundant and spurious tracks. Multi-sensor networks will generally attempt to estimate the relevant bias values (usually, during sensor registration), and use the estimates to debias the sensor measurements and correct the reference frame transformations. Unfortunately, the biases and navigation errors are stochastic, and the estimates of the means account only for the "deterministic" part of the biases. The remaining stochastic errors are termed "residual" biases and are …

Exact P-Values For Discrete Models Obtained By Estimation And Maximisation, Chris Lloyd

Chris J. Lloyd

In constructing exact tests, one must deal with the possible dependence of the P-value on the nuisance parameter/s psi as well as discreteness of the sample space. A classical but heavy handed approach is to maximise over psi. We prove what has previously been understood informally, namely that maximisation produces the uinique and smallest possible P-value subject to the ordering induced by the underlying test statistic and test validity. On the other hand, allowing for the worst case will be more attractive when the P-value is less dependent on psi. We investigate the extent to which estimating psi under the …

Functional Principal Component Regression And Functional Partial Least Squares, Philip T. Reiss, R. Todd Ogden

Philip T. Reiss

Regression of a scalar response on signal predictors, such as near-infrared (NIR) spectra of chemical samples, presents a major challenge when, as is typically the case, the dimension of the signals far exceeds their number. Most solutions to this problem reduce the dimension of the predictors either by regressing on components--e.g. principal component regression (PCR) and partial least squares (PLS)--or by smoothing methods which restrict the coefficient function to the span of a spline basis. This paper introduces functional versions of PCR and PLS, which combine both of the above dimension reduction approaches. Two versions of functional PCR are developed, …

Mobile Information Communication Technology For Crisis Management : Understanding User Behavior, Response And Training, Elizabeth Avery Gomez

Dissertations

SMS text-messaging is an interoperable communication vehicle known to be dependable for mass media alert notifications in crisis management. SMS text-messaging also offers potential as one viable two-way communication alternative for field responders in crisis response. Both continuously changing mobile information communication technologies and the importance of precise information exchange constitute a need for communication protocol training and practice. This study introduces a technology-mediated training technique based on speech act and communicative action theories. These theories are used to inform the design of a baseline measure for task performance improvement and to suggest a model to predict communication readiness. Because …

Design And Application Of Near Infrared Tunable Filter For Atst And Nst, Jun Ma

Dissertations

This thesis includes the following sections: a general design of the Near Infrared Tunable Filter (NIRTF) of Advanced Technology Solar Telescope (ATST) project and the Near Infrared Imaging Magnetograph (IRIM) of the New Solar Telescope (NST), the design of achromatic waveplates, the narrowband continuum observation of a Sunspot at 1.56 µm using IRIM instruments, and the coronal hole observation using the Digital Vector Magnetograph (VMG) at Big Bear Solar Observatory (BBSO).

A near infrared tunable filter system is designed with detailed optical parameters for each component in the system. Among these components, the achromatic waveplates, which used to be an …

Designing Multimodal Interaction For The Visually Impaired, Xiaoyu Chen

Dissertations

Although multimodal computer input is believed to have advantages over unimodal input, little has been done to understand how to design a multimodal input mechanism to facilitate visually impaired users' information access.

This research investigates sighted and visually impaired users' multimodal interaction choices when given an interaction grammar that supports speech and touch input modalities. It investigates whether task type, working memory load, or prevalence of errors in a given modality impact a user's choice. Theories in human memory and attention are used to explain the users' speech and touch input coordination.

Among the abundant findings from this research, the …

Interaction Of Methoxyethyl Methyl Imidazolium-Based Ionic Liquids With Uranium And Its Effect On Bioreduction Of Uranium, Hao Wang

Dissertations

Ionic liquids (ILs) are new materials with unique properties such as non-measurable vapor pressure, low melting point below 100°C and tunable physical-chemical properties. These liquids demonstrate tremendous potential applications in many fields, including nuclear waste treatment.

In this study, new MOEMIM (methoxyethyl methyl imidazolium)-based ionic liquids were synthesized. Their properties were characterized by UV-Vis spectroscopy (UV-vis), Fourier transform infrared spectroscopy (ETIR), mass spectroscopy (MS) and NMR (Nuclear magnetic resonance). The interaction between ILs and uranium has been explored by various analysis techniques, including pH, potentiometric titration, UV-vis, MS and EXAFS (extended x-ray absorption fine structure). Among all the ILs studied …

Design And Implementation Of Split Tcp In The Linux Kernel, Rahul Jain

Dissertations

The Transmission Control Protocol (TCP) was designed for reliable communication between computers over networks of unpredictable quality. It has admirably succeeded in satisfying the needs of the growing internet. Yet, there are combinations of network problems too bad even for TCP. In particular, in the situation of simultaneously very high delay (e.g. a satellite link) and high loss or even fading (a low quality earthlink or wireless link) on the same connection TCP can break down.

A known solution is “Split TCP” where one or more proxies (called Helper Boxes) are introduced to break the end-to-end connection into few (almost) …

Solar Activity Detection And Prediction Using Image Processing And Machine Learning Techniques, Gang Fu

Dissertations

The objective of the research in this dissertation is to develop the methods for automatic detection and prediction of solar activities, including prominence eruptions, emerging flux regions and solar flares. Image processing and machine learning techniques are applied in this study. These methods can be used for automatic observation of solar activities and prediction of space weather that may have great influence on the near earth environment.

The research presented in this dissertation covers the following topics: i) automatic detection of prominence eruptions (PBs), ii) automatic detection of emerging flux regions (EFRs), and iii) automatic prediction of solar flares.

In …

Design, Fabrication And Testing Of A Fiber Optic Stress/Strain Sensor For Soft Stretchable Materials Using Polarization Imaging Technique, Jianjun Zheng

Dissertations

The polarization imaging technique has been used to obtain high quality surface images of turbid media. This technique can be slightly modified and used for noninvasive sensing of strain and stress in soft stretchable materials, such as latex and human tissues. Previously this sensing method was developed with free space bulk optics. In this study, a fiber optic based system is developed to investigate the potential application of this technology on the strain/stress as well as surface roughness measurements of stretchable materials. In this system, polarizers are simply attached to the fiber ends to form a polarizing three-fiber probe. Furthermore, …

Ab Initio Study Of Hydrogen Adsorption On Benzenoid Linkers In Metal–Organic Framework Materials, Yi Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We have computed the energies of adsorption of molecular hydrogen on a number of molecular linkers in metal–organic framework solid materials using density functional theory (DFT) and ab initio molecular orbital methods. We find that the hybrid B3LYP (Becke three-parameter Lee–Yang–Parr) DFT method gives a qualitatively incorrect prediction of the hydrogen binding with benzenoid molecular linkers. Both local-density approximation (LDA) and generalized gradient approximation (GGA) DFT methods are inaccurate in predicting the values of hydrogen binding energies, but can give a qualitatively correct prediction of the hydrogen binding. When compared to the more accurate binding- energy results based on the …

Education In The Environment: A Strategy For Continued Interagency Outdoor Programming: Quarterly Progress Report, Period Ending August 31, 2007, Environmental Education Strategy For Nevada

Reports (PLI Education)

During the past three months, the focus of the university’s efforts has included the following highlights:

• Three projects have been identified to meet SNAP strategic messaging needs: an anti-litter exhibit; a volunteer restoration program with educational components; and activity stations to tell the story of Lee Meadows restoration efforts.
• Interpretive planning is underway for Mountain’s Edge Explorer’s Interpretive Trail.
• A Hispanic survey and monitoring program has been identified.
• A six-week Spanish class tailored to meet the communication needs of environmental educators and interpreters will be offered beginning September 20.
• Forever Earth was scheduled for 11 days and benefited 297 individuals. …

Distributing Real Time Data From A Multi-Node Large Scale Contact Center Using Corba, Joe Goggins

Regis University Student Publications (comprehensive collection)

This thesis researches and evaluates the current technologies available for developing a system for propagation of Real-Time Data from a large scale Enterprise Server to large numbers of registered clients on the network. The large scale Enterprise Server being implemented is a Contact Centre Server, which can be a standalone system or part of a multi-nodal system. This paper makes three contributions to the study of scalable real-time notification services. Firstly, it defines the research of the different technologies and their implementation for distributed objects in today's world of computing. Secondly, the paper explains how we have addressed key design …

Hydrodynamic And Magnetohydrodynamic Computations Inside A Rotating Sphere, P. D. Mininni, D. C. Montgomery, L. Turner

Dartmouth Scholarship

Numerical solutions of the incompressible magnetohydrodynamic (MHD) equations are reported for the interior of a rotating, perfectly-conducting, rigid spherical shell that is insulator-coated on the inside. A previously-reported spectral method is used which relies on a Galerkin expansion in Chandrasekhar–Kendall vector eigenfunctions of the curl. The new ingredient in this set of computations is the rigid rotation of the sphere. After a few purely hydrodynamic examples are sampled (spin down, Ekman pumping, inertial waves), attention is focused on selective decay and the MHD dynamo problem. In dynamo runs, prescribed mechanical forcing excites a persistent velocity field, usually turbulent at modest …