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Brigham Young University

2009

Articles 1 - 30 of 115

Full-Text Articles in Physical Sciences and Mathematics

Equalization Of Loudspeakers And Enclosed Sound Fields, Xi Chen Dec 2009

Equalization Of Loudspeakers And Enclosed Sound Fields, Xi Chen

Theses and Dissertations

Equalization of loudspeakers and enclosed sound fields has been a topic of considerable interest for decades. Confusion has often arisen among audio professionals regarding the feasibility of simultaneously equalizing a loudspeaker and the enclosed field (i.e., the “room”) it excites. Because of frustrations encountered in such efforts, some have advocated abandoning simultaneous equalization altogether. This dissertation discusses the drawbacks of this approach as well as traditional in situ equalization methods. It demonstrates that many problems with traditional equalization stem from the use of measured acoustic pressure at a discrete point in a sound field as the system output. The dissertation …

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Carbon Coated Tellurium For Optical Data Storage, Jonathan D. Abbott Dec 2009

Carbon Coated Tellurium For Optical Data Storage, Jonathan D. Abbott

Theses and Dissertations

A highly durable optical disk has been developed for data archiving. This optical disk uses tellurium as the write layer and carbon as a dielectric and oxidation prevention layer. The sandwich style CTeC film was deposited on polycarbonate and silicon substrates by plasma sputtering. These films were then characterized with SEM, TEM, EELS, ellipsometry, ToF-SIMS, etc, and were tested for writability and longevity. Results show the films were uniform in physical structure, are stable, and able to form permanent pits. Data was written to a disk and successfully read back in a commercial DVD drive.

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Measured Optical Constants Of Copper From 10 Nm To 35 Nm, David D. Allred, Nicole Brimhall, Nicholas Herrick, Justin Peatross, R. Steven Turley, Michael Ware Dec 2009

Measured Optical Constants Of Copper From 10 Nm To 35 Nm, David D. Allred, Nicole Brimhall, Nicholas Herrick, Justin Peatross, R. Steven Turley, Michael Ware

Faculty Publications

We use laser high-order harmonics and a polarization-ratioreflectance technique to determine the optical constants of copper and oxidized copper in the wavelength range 10-35 nm. This measurement resolves previously conflicting data sets, where disagreement on optical constants of copper in the extreme ultraviolet most likely arises from inadvertent oxidation of samples before measurement.

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Progress Toward The Total Synthesis Of Lyconadin A, Yu Zhang Dec 2009

Progress Toward The Total Synthesis Of Lyconadin A, Yu Zhang

Theses and Dissertations

Lyconadin A is a pentacyclic Lycopodium alkaloid isolated from the club moss Lycopodium complanatum with antitumor properties. We have developed a novel 7-exo/6-exo acyl radical cascade cyclization as a method of making the bicyclo[5.4.0]undecane ring system of lyconadin A. The model products are trans-fused ring systems, while a cis-fused ring system is needed in lyconadin A. We have discovered a method to convert the trans-fused model cascade cyclization product into the desired cis isomer. Based on Donohoe's pyridone synthesis, we developed a method for the construction of 5-alkyl and 3,5-dialkyl-6-carbomethoxy-2-pyridones, the former of which …

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Analysis Of Electromagnetic And Seismic Geophysical Methods For Investigating Shallow Sub-Surface Hydrogeology, Eric M. Parks Dec 2009

Analysis Of Electromagnetic And Seismic Geophysical Methods For Investigating Shallow Sub-Surface Hydrogeology, Eric M. Parks

Theses and Dissertations

An integrated electromagnetic (EM) and seismic geophysical study was performed to evaluate non-invasive approaches to estimate depth to shallow groundwater in arid environments with elevated soil salinity where the installation of piezometers would be impractical or prohibited. Both methods were tested in two study areas (semi-arid and arid respectively), one in Palmyra, Utah, USA near the shore of Utah Lake where groundwater is shallow and unconfined in relatively homogeneous lacustrine sediments. The other area is Carson Slough, Nevada, USA near Ash Meadows National Wildlife Refuge in Amargosa Valley. The area is underlain by valley fill, with generally variable shallow depths …

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Bisecting Document Clustering Using Model-Based Methods, Aaron Samuel Davis Dec 2009

Bisecting Document Clustering Using Model-Based Methods, Aaron Samuel Davis

Theses and Dissertations

We all have access to large collections of digital text documents, which are useful only if we can make sense of them all and distill important information from them. Good document clustering algorithms that organize such information automatically in meaningful ways can make a difference in how effective we are at using that information. In this paper we use model-based document clustering algorithms as a base for bisecting methods in order to identify increasingly cohesive clusters from larger, more diverse clusters. We specifically use the EM algorithm and Gibbs Sampling on a mixture of multinomials as the base clustering algorithms …

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Interactive Football Summarization, Brandon B. Moon Dec 2009

Interactive Football Summarization, Brandon B. Moon

Theses and Dissertations

Football fans do not have the time to watch every game in its entirety and need an effective solution that summarizes them the story of the game. Human-generated summaries are often too short, requiring time and resources to create. We utilize the advantages of Interactive TV to create an automatic football summarization service that is cohesive, provides context, covers the necessary plays, and is concise. First, we construct a degree of interest function that ranks each play based on detailed, play-by-play game events as well as viewing statistics collected from an interactive viewing environment. This allows us to select the …

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Fused Visible And Infrared Video For Use In Wilderness Search And Rescue, Dennis Eggett, Michael A. Goodrich, Bryan S. Morse, Nathan Rasmussen Dec 2009

Fused Visible And Infrared Video For Use In Wilderness Search And Rescue, Dennis Eggett, Michael A. Goodrich, Bryan S. Morse, Nathan Rasmussen

Faculty Publications

Mini Unmanned Aerial Vehicles (mUAVs) have the potential to assist Wilderness Search and Rescue groups by providing a bird’s eye view of the search area. This paper proposes a method for augmenting visible-spectrum searching with infrared sensing in order to make use of thermal search clues. It details a method for combining the color and heat information from these two modalities into a single fused display to reduce needed screen space for remote field use. To align the video frames for fusion, a method for simultaneously pre-calibrating the intrinsic and extrinsic parameters of the cameras and their mount using a …

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Noninvasive Estimation Of Pulmonary Artery Pressure Using Heart Sound Analysis, Aaron W. Dennis Dec 2009

Noninvasive Estimation Of Pulmonary Artery Pressure Using Heart Sound Analysis, Aaron W. Dennis

Theses and Dissertations

Right-heart catheterization is the most accurate method for estimating pulmonary artery pressure (PAP). Because it is an invasive procedure it is expensive, exposes patients to the risk of infection, and is not suited for long-term monitoring situations. Medical researchers have shown that PAP influences the characteristics of heart sounds. This suggests that heart sound analysis is a potential noninvasive solution to the PAP estimation problem. This thesis describes the development of a prototype system, called PAPEr, which estimates PAP noninvasively using heart sound analysis. PAPEr uses patient data with machine learning algorithms to build models of how PAP affects heart …

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An Adaptive Bayesian Approach To Dose-Response Modeling, Thomas J. Leininger Dec 2009

An Adaptive Bayesian Approach To Dose-Response Modeling, Thomas J. Leininger

Theses and Dissertations

Clinical drug trials are costly and time-consuming. Bayesian methods alleviate the inefficiencies in the testing process while providing user-friendly probabilistic inference and predictions from the sampled posterior distributions, saving resources, time, and money. We propose a dynamic linear model to estimate the mean response at each dose level, borrowing strength across dose levels. Our model permits nonmonotonicity of the dose-response relationship, facilitating precise modeling of a wider array of dose-response relationships (including the possibility of toxicity). In addition, we incorporate an adaptive approach to the design of the clinical trial, which allows for interim decisions and assignment to doses based …

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Gpu-Accelerated Hierarchical Dense Correspondence For Real-Time Aerial Video Processing, Stephen Cluff, Bryan S. Morse, Jonathan D. Cohen, Mark Duchaineau Dec 2009

Gpu-Accelerated Hierarchical Dense Correspondence For Real-Time Aerial Video Processing, Stephen Cluff, Bryan S. Morse, Jonathan D. Cohen, Mark Duchaineau

Faculty Publications

Video from aerial surveillance can provide a rich source of data for many applications and can be enhanced for display and analysis through such methods as mosaic construction, super-resolution, and mover detection. All of these methods require accurate frame-to-frame registration, which for live use must be performed in real time. In many situations, scene parallax may make alignment using global transformations impossible or error-prone, limiting the performance of subsequent processing and applications. For these cases, dense (per-pixel) correspondence is required, but this can be computationally prohibitive. This paper presents a hierarchical dense correspondence algorithm designed for implementation on graphics processing …

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Open Access Fiber To The Home Networking, Roger E. Timmerman Dec 2009

Open Access Fiber To The Home Networking, Roger E. Timmerman

Theses and Dissertations

The concept of open-access networks appeals to communities that want to invest in and improve their access to modern telecommunications services. By investing in, or building their own open-access telecommunications networks, communities can create an environment where several telecommunications service providers can co-exist on a common open-access infrastructure. This model promotes innovation and competition among several smaller service providers rather than having a monopoly or oligopoly from those companies that can afford the investment of infrastructure in the community. This research provides an analysis of two large open-access fiber-to-the-home networks in Utah to determine a set of recommendations and best-practices …

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Using Operator Teams For Supervisory Control, Jonathan M. Whetten Nov 2009

Using Operator Teams For Supervisory Control, Jonathan M. Whetten

Theses and Dissertations

Robots and other automated systems have potential use in many different fields. As the scope of robot applications that robots are used for increases, there is a growing desire to have human operators manage multiple robots. Typical methods of enabling operators to multi-task in this way involve some combination of user interfaces that support human cognition and advanced robot autonomy. Our research explores a complementary method of managing multiple robots by utilizing operator teams. The evidence suggests that for appropriate task scenarios, two cooperating operators can be more than twice as effective as one operator working alone.

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Dinosaurian Faunas Of The Cedar Mountain Formation And La-Icp-Ms Detrital Zircon Ages For Three Stratigraphic Sections, Hirotsugu Mori Nov 2009

Dinosaurian Faunas Of The Cedar Mountain Formation And La-Icp-Ms Detrital Zircon Ages For Three Stratigraphic Sections, Hirotsugu Mori

Theses and Dissertations

The Cedar Mountain Formation contains the most diverse record of Early Cretaceous dinosaurs in the western hemisphere. However, analyses of its faunas have been hindered because 1) most taxa are based on incomplete/fragmentary materials or incomplete descriptions, 2) most sites and some horizons preserve few taxa, and 3) the stratigraphy and geochronology are poorly understood. To help resolve these stratigraphic and correlation problems U-Pb LA-ICP-MS detrital zircon ages were obtained at significant sites and horizons. These dates indicate all sites at or near the base of the formation are no older than 122 to 124 Ma, thus all basal stratigraphic …

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Hokua – A Wavelet Method For Audio Fingerprinting, Steven S. Lutz Nov 2009

Hokua – A Wavelet Method For Audio Fingerprinting, Steven S. Lutz

Theses and Dissertations

In recent years, multimedia identification has become important as the volume of digital media has dramatically increased. With music files, one method of identification is audio fingerprinting. The underlying method for most algorithms is the Fourier transform. However, due to a lack of temporal resolution, these algorithms rely on the short-time Fourier transform. We propose an audio fingerprinting algorithm that uses a wavelet transform, which has good temporal resolution. In this thesis, we examine the basics of certain topics that are needed in understanding audio fingerprinting techniques. We also look at a brief history of work done in this field. …

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An Empirical Study Of Instance Hardness, Michael Reed Smith Nov 2009

An Empirical Study Of Instance Hardness, Michael Reed Smith

Theses and Dissertations

Most widely accepted measures of performance for learning algorithms, such as accuracy and area under the ROC curve, provide information about behavior at the data set level. They say nothing about which instances are misclassified, whether two learning algorithms with the same classification accuracy on a data set misclassify the same instances, or whether there are instances misclassified by all learning algorithms. These questions about behavior at the instance level motivate our empirical analysis of instance hardness, a measure of expected classification accuracy for an instance. We analyze the classification of 57 data sets using 9 learning algorithms. Of …

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Synthesis And Evaluation Of N6,5'-Bis-Ureido-5'-Amino-5'-Deoxyadenosine Derivatives: Novel Nucleosides With Antiproliferative And Protein Kinase Binding Activities, Marcelio Oliveira Nov 2009

Synthesis And Evaluation Of N6,5'-Bis-Ureido-5'-Amino-5'-Deoxyadenosine Derivatives: Novel Nucleosides With Antiproliferative And Protein Kinase Binding Activities, Marcelio Oliveira

Theses and Dissertations

A new series of N6,5'-bis-ureido-5'-amino-5'-deoxyadenosine derivatives was prepared and evaluated for anticancer activities using the NCI 60 panel of human cancers. Certain of the derivatives showed promising activities (low micromolar GI50's) against several of the representative cancers. These included cell lines from the following general cell types in the NCI 60: Leukemia, Breast, Central Nervous System, Non-Small Cell Lung, Ovarian, Prostate, Renal, and Colon cancers. Select compounds were also screened for their affinities for protein kinases. The synthesis of the compounds was straightforward and involved N6 acylation with arylisocyanates, preceded by activation and nucleophilic substitution of the 5'-position to give …

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Growth And Geodesics Of Thompson's Group F, Jennifer L. Schofield Nov 2009

Growth And Geodesics Of Thompson's Group F, Jennifer L. Schofield

Theses and Dissertations

In this paper our goal is to describe how to find the growth of Thompson's group F with generators a and b. Also, by studying elements through pipe systems, we describe how adding a third generator c affects geodesic length. We model the growth of Thompson's group F by producing a grammar for reduced pairs of trees based on Blake Fordham's tree structure. Then we change this grammar into a system of equations that describes the growth of Thompson's group F and simplify. To complete our second goal, we present and discuss a computer program that has led to some …

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Feature-Based Interactive Terrain Sketching, Daniel B. Adams Nov 2009

Feature-Based Interactive Terrain Sketching, Daniel B. Adams

Theses and Dissertations

Procedural generation techniques are able to quickly and cheaply produce large areas of terrain. However, these techniques produce results that are not easily directable and often require artists to edit the results by hand to achieve the desired layout. This paper proposes a sketch-based system for controlling fractal terrain that allows for a wide variety of terrain feature types. Artists sketch features rather than constrained points or elevations. The system is interactive, provides quick on-demand previews of the terrain, and allows for iterative design modifications. Interaction between features is handled in a realistic fashion. An arbitrary vertex insertion order midpoint …

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A La-Icpms Sr Isotope And Trace Element Study Of Plagioclase And Clinopyroxene Of The Higganum Dike, Connecticut: Determining The Magma Source Of The Central Atlantic Magmatic Province, Caprise Steadman Harper Nov 2009

A La-Icpms Sr Isotope And Trace Element Study Of Plagioclase And Clinopyroxene Of The Higganum Dike, Connecticut: Determining The Magma Source Of The Central Atlantic Magmatic Province, Caprise Steadman Harper

Theses and Dissertations

The Higganum dike of Connecticut is one of the earliest basaltic dikes of the Central Atlantic Magmatic province and is geochemically representative of the widespread low-Ti basaltic lavas (~1 wt % TiO2) that make up the majority of the province in North America. Liquid compositions calculated from Cr-rich clinopyroxene cores from the Higganum dike are significantly more primitive than the bulk rock with average Mg# s of 0.63 compared to the Higganum dike which has Mg #'s ~ 0.55. However, the negative Nb and positive Pb anomalies that are seen in trace element patterns of the low-Ti group are also …

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Parameter Estimation For The Lognormal Distribution, Brenda Faith Ginos Nov 2009

Parameter Estimation For The Lognormal Distribution, Brenda Faith Ginos

Theses and Dissertations

The lognormal distribution is useful in modeling continuous random variables which are greater than or equal to zero. Example scenarios in which the lognormal distribution is used include, among many others: in medicine, latent periods of infectious diseases; in environmental science, the distribution of particles, chemicals, and organisms in the environment; in linguistics, the number of letters per word and the number of words per sentence; and in economics, age of marriage, farm size, and income. The lognormal distribution is also useful in modeling data which would be considered normally distributed except for the fact that it may be more …

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Classifying Sentence-Based Summaries Of Web Documents, Yiu-Kai D. Ng, Maria Soledad Pera Nov 2009

Classifying Sentence-Based Summaries Of Web Documents, Yiu-Kai D. Ng, Maria Soledad Pera

Faculty Publications

Text classification categorizes Web documents in large collections into predefined classes based on their contents. Unfortunately, the classification process can be time-consuming and users are still required to spend considerable amount of time scanning through the classified Web documents to identify the ones that satisfy their information needs. In solving this problem, we first introduce CorSum, an extractive single-document summarization approach, which is simple and effective in performing the summarization task, since it only relies on word similarity to generate high-quality summaries. Hereafter, we train a Naïve Bayes classifier on CorSum-generated summaries and verify the classification accuracy using the summaries …

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Chemalign: Biologically Relevant Multiple Sequence Alignment Using Physicochemical Properties, Hyrum Carroll, Mark J. Clement, Quinn O. Snell, David Mcclellan Nov 2009

Chemalign: Biologically Relevant Multiple Sequence Alignment Using Physicochemical Properties, Hyrum Carroll, Mark J. Clement, Quinn O. Snell, David Mcclellan

Faculty Publications

We present a new algorithm, ChemAlign, that uses physicochemical properties and secondary structure elements to create biologically relevant multiple sequence alignments (MSAs). Additionally, we introduce the Physicochemical Property Difference (PPD) score for the evaluation of MSAs. This score is the normalized difference of physicochemical property values between a calculated and a reference alignment. It takes a step beyond sequence similarity and measures characteristics of the amino acids to provide a more biologically relevant metric. ChemAlign is able to produce more biologically correct alignments and can help to identify potential drug docking sites.

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Mcc: A Runtime Verification Tool For Mcapi User Applications, Eric G. Mercer, Ganesh Gopalakrishnan, Jim Holt, Subodh Sharma Nov 2009

Mcc: A Runtime Verification Tool For Mcapi User Applications, Eric G. Mercer, Ganesh Gopalakrishnan, Jim Holt, Subodh Sharma

Faculty Publications

We present a dynamic verification tool MCC for Multicore Communication API applications – a new API for communication among cores. MCC systematically explores all relevant interleavings of an MCAPI application using a tailormade dynamic partial order reduction algorithm (DPOR). Our contributions are (i) a way to model the non-overtaking message matching relation underlying MCAPI calls with a high level algorithm to effect DPOR for MCAPI that controls the lower level details so that the intended executions happen at runtime; and (ii) a list of default safety properties that can be utilized in the process of verification. To our knowledge, this …

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Isotopic Evaluation Of Carbon Dioxide In Soil Gas In Utah For A More Accurate Input Variable In Groundwater Age Determining Models, Rachelle Hart Oct 2009

Isotopic Evaluation Of Carbon Dioxide In Soil Gas In Utah For A More Accurate Input Variable In Groundwater Age Determining Models, Rachelle Hart

Theses and Dissertations

In order to achieve a more accurate input value for groundwater age determining models, δ13CVPDB values for soil gas were evaluated at 50 cm depths in locations throughout Utah in order to define correlations between δ13C and environmental parameters. 16 sites were chosen that exploited large changes in elevation and latitude which provided variations in climate, precipitation, plant community, etc. Gas samples were collected over 1-1½ years, and soil samples were collected at depth during installations. Field and laboratory studies were also used to evaluate CO2 and δ13C change with depth. It was discovered that in mountainous recharge areas, the …

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Development And Comparison Of Methods For Measuring Directional Sound Arrivals In Rooms, Brian Trevor Thornock Oct 2009

Development And Comparison Of Methods For Measuring Directional Sound Arrivals In Rooms, Brian Trevor Thornock

Theses and Dissertations

In room acoustics, the directional information of sound arrivals at a listening location can be used to diagnose the origins of problematic reflections so offending surfaces or other features can be properly treated. It can also be used for other purposes, including the study of psychoacoustic indicators. Many methods have been developed in the past to derive directional information, but despite their benefits, each has had significant drawbacks that have necessitated further research into their properties and development of an improved method. This thesis presents a review of past methods, their benefits and shortcomings. It discusses many theoretical and practical …

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Livecut: Learning-Based Interactive Video Segmentation By Evaluation Of Multiple Propagated Cues, Bryan S. Morse, Brian L. Price, Scott Cohen Oct 2009

Livecut: Learning-Based Interactive Video Segmentation By Evaluation Of Multiple Propagated Cues, Bryan S. Morse, Brian L. Price, Scott Cohen

Faculty Publications

Video sequences contain many cues that may be used to segment objects in them, such as color, gradient, color adjacency, shape, temporal coherence, camera and object motion, and easily-trackable points. This paper introduces LIVEcut, a novel method for interactively selecting objects in video sequences by extracting and leveraging as much of this information as possible. Using a graph-cut optimization framework, LIVEcut propagates the selection forward frame by frame, allowing the user to correct any mistakes along the way if needed. Enhanced methods of extracting many of the features are provided. In order to use the most accurate information from the …

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Versatile Reactive Navigation, Robert P. Burton, Luther A. Tychonievich, Louis P. Tychonievich Oct 2009

Versatile Reactive Navigation, Robert P. Burton, Luther A. Tychonievich, Louis P. Tychonievich

Faculty Publications

Most autonomous mobile agents operate in a highly constrained environment. Despite significant research, existing solutions are limited in their ability to handle heterogeneous constraints within highly dynamic or uncertain environments. This paper presents a novel maneuver selection technique suited for both 2D and 3D environments with highly dynamic maneuvering constraints and multiple mobile obstacles. Agents may have any arbitrary set of nonholonomic control variables; maneuvers can be constrained by a broad class of function inequalities, including time-dependent constraints involving nonlinear relationships between controlled and agent-state variables. The resulting algorithm has been implemented to run in real time using only a …

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Uav Intelligent Path Planning For Wilderness Search And Rescue, Michael A. Goodrich, Lanny Lin Oct 2009

Uav Intelligent Path Planning For Wilderness Search And Rescue, Michael A. Goodrich, Lanny Lin

Faculty Publications

In the priority search phase of Wilderness Search and Rescue, a probability distribution map is created. Areas with higher probabilities are searched first in order to find the missing person in the shortest expected time. When using a UAV to support search, the onboard video camera should cover as much of the important areas as possible within a set time. We explore several algorithms (with and without set destination) and describe some novel techniques in solving this problem and compare their performances against typical WiSAR scenarios. This problem is NP-hard, but our algorithms yield high quality solutions that approximate the …

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Pore Size Characterization Of Monolithic Capillary Columns Using Capillary Flow Porometry, Yan Fang Sep 2009

Pore Size Characterization Of Monolithic Capillary Columns Using Capillary Flow Porometry, Yan Fang

Theses and Dissertations

A simple capillary flow porometer (CFP) was assembled for pore structure characterization of monolithic capillary liquid chromatography columns based on ASTM standard F316-86. Determination of differential pressures and flow rates through dry and wet samples provided the necessary information to determine the through-pore throat diameter, bubble point pore diameter, mean flow pore diameter, and pore distribution. Unlike measurements in bulk using traditional techniques to provide indirect information about the pore properties of monolithic columns, monoliths can be characterized in their original chromatographic forms with this system. The performance of the new CFP was first evaluated by characterizing the pore size …

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