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Interval Computations As A Particular Case Of A General Scheme Involving Classes Of Probability Distributions, Scott Ferson, Lev Ginzburg, Vladik Kreinovich, Harry Schulte Mar 2001

Interval Computations As A Particular Case Of A General Scheme Involving Classes Of Probability Distributions, Scott Ferson, Lev Ginzburg, Vladik Kreinovich, Harry Schulte

Departmental Technical Reports (CS)

Traditionally, in science and engineering, measurement uncertainty is characterized by a probability distribution; however, we don't know this probability distribution exactly, so we must consider classes of probability distributions. Interval computations deal with a very specific type of such classes: classes of all distributions which are located on a given interval. We show that in general, we need all convex classes of probability distributions.

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1st Order, 2nd Order, What Next? Do We Really Need Third-Order Descriptions: A View From A Realistic (Granular) Viewpoint, Vladik Kreinovich, Hung T. Nguyen Mar 2001

1st Order, 2nd Order, What Next? Do We Really Need Third-Order Descriptions: A View From A Realistic (Granular) Viewpoint, Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

To describe experts' uncertainty in a knowledge-based system, we usually use numbers from the interval [0,1] (subjective probabilities, degrees of certainty, etc.). The most direct way to get these numbers is to ask the expert; however, the expert may not be 100\% certain what exactly number describes his uncertainty; so, we end up with a second-order uncertainty - a degree of certainty describing to what extent a given number d adequately describes the expert's uncertainty about a given statement A. At first glance, it looks like we should not stop at this second order: the expert is probably as uncertain …

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On The Solution Of A Class Of Large Body Problems With Partial Circular Symmetry (Multiple Asymmetries) By Using A Hybrid-Dimensional Finite-Difference Time-Domain (Fdtd) Method, Dean Arakaki, Wenhua Yu, Raj Mittra Mar 2001

On The Solution Of A Class Of Large Body Problems With Partial Circular Symmetry (Multiple Asymmetries) By Using A Hybrid-Dimensional Finite-Difference Time-Domain (Fdtd) Method, Dean Arakaki, Wenhua Yu, Raj Mittra

Electrical Engineering

This paper presents an efficient method to solve a large body scattering problem, viz. a paraboloid reflector antenna system, with only partial circular symmetry. The asymmetry in the system is introduced by two factors, viz. the microstrip feed and an inhomogeneous radome. The paper presents a novel approach, based on the equivalence and reciprocity principles and the “equivalent” aperture theory, to overcome the asymmetry problem. The technique thereby enables substantial computational efficiencies by analyzing the majority of the three-dimensional (3-D) computational domain in an effective two-dimensional (2-D) simulation, with the remainder being analyzed using a 3-D algorithm.

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Flight Physician - March, 2001, Civil Aviation Medical Association Mar 2001

Flight Physician - March, 2001, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A seventeen page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

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The Use Of Systems Engineering Processes And Tools To Develop A System Dynamic Simulation Model Of Engineering Support During The Development Phase Of An Acquisition Program, Jason E. Bartolomei Mar 2001

The Use Of Systems Engineering Processes And Tools To Develop A System Dynamic Simulation Model Of Engineering Support During The Development Phase Of An Acquisition Program, Jason E. Bartolomei

Theses and Dissertations

Due to the increase of system complexity and the existing draw down of manpower allocations, today's acquisitions environment desperately needs a systems approach to decision making. Many studies have been performed to model the entire government acquisition environment. Due to the high degree of aggregation, front line decision-makers have had no use for the information these models provide. This research focuses on the Air Force's largest functional support element in aircraft systems development, engineering. I will only consider one phase of the government acquisition cycle the Engineering, Manufacturing, and Development (EMD). This is the development cycle, which begins with initial …

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Optical And Etching Studies Of Native Aluminum Oxide Layers For Use In Microcavity Photonic Devices, William L. Bernhard Mar 2001

Optical And Etching Studies Of Native Aluminum Oxide Layers For Use In Microcavity Photonic Devices, William L. Bernhard

Theses and Dissertations

Optical communication and computing systems are required to meet future information transfer and processing needs. Microcavity devices serve as an enabling technology to implement and integrate optoelectronic systems. It is important to understand the optical and mechanical properties of materials utilize within microcavity devices. Only then is it possible to accurately model and analyze structures. Microcavity structures incorporating a high aluminum content AlGaAs layers are designed, grown, processed, and measured. The processing of these devices includes the conversion of high aluminum-content AlGaAs layers to native aluminum oxide (AlO) layers through the process of thermal oxidation. This selective conversion of microcavity …

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The Effect Of External Safeguards On Human-Information System Trust In An Information Warfare Environment, Gregory S. Fields Mar 2001

The Effect Of External Safeguards On Human-Information System Trust In An Information Warfare Environment, Gregory S. Fields

Theses and Dissertations

This research looks at how human trust in an information system is influenced by external safeguards in an Information Warfare (1W) domain. Information systems are relied upon in command and control environments to provide fast and reliable information to the decision-makers. The degree of reliance placed in these systems by the decision-makers suggests a significant level of trust. Understanding this trust relationship and what effects it is the focus of this study. A model is proposed that predicts behavior associated with human trust in information systems. It is hypothesized that a decision-maker's belief in the effectiveness of external safeguards will …

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Numerical Study Of Optical Delay In Semiconductor Multilayer Distributed Bragg Reflector And Tunable Microcavity Structures, Michael I. K. Etan Mar 2001

Numerical Study Of Optical Delay In Semiconductor Multilayer Distributed Bragg Reflector And Tunable Microcavity Structures, Michael I. K. Etan

Theses and Dissertations

The Air Force has a growing need for the greater bandwidth, speed, and flexibility offered by optical communication links. Future space systems and airborne platforms will most likely use optical signals for efficient power transmission and to minimize the possibility of spoofing and eavesdropping. Tunable optical delays play an important role in the implementation of free space optical communication links. The primary challenge in implementing these systems is the active maintenance of coherent wave fronts across the system's optical aperture. For space applications, this aperture may he hundreds of meters in diameter. Spatial segmentation of a large aperture into smaller …

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Influence Of Feedback And Comment Labels On Information Sharing In A Computer Mediated Collaborative Environment, Gary D. Denney Mar 2001

Influence Of Feedback And Comment Labels On Information Sharing In A Computer Mediated Collaborative Environment, Gary D. Denney

Theses and Dissertations

A group support system (GSS) uses a combination of networked personal computers, software, and human facilitation to improve the group decision-making process. Group support Systems are being used in the Air Force today in a variety of capacities and in particular by the Warner-Robins Air Logistics Center (WR-ALC) to assess acquisition risks. Prior GSS research has found that certain structural and social dimensions of GSS designs might influence whether optimal process improvements take place. However, the dimensions that positively influence group performance have continued to be a matter of debate. This thesis looked at several structural and social contingencies to …

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Using Direct-Sequenced Spread Spectrum In A Wired Local Area Network, Robert J. Bonner Mar 2001

Using Direct-Sequenced Spread Spectrum In A Wired Local Area Network, Robert J. Bonner

Theses and Dissertations

Code division multiple access provides an ability to share channel bandwidth amongst users at the same time. Individual user performance is not degraded with the addition of more users, unlike traditional Ethernet. Using direct sequenced spread spectrum in a wired local area network, network performance is improved. For a network in overload conditions, individual station throughput is increased by nearly 212% while mean end-to-end delay was reduced by 800%. The vast improvement demonstrated by this research has the capability to extend legacy-cabling infrastructures for many years to come while easily accommodating new bandwidth intensive multimedia applications.

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A Low Power Application-Specific Integrated Circuit (Asic) Implementation Of Wavelet Transform/Inverse Transform, Daniel N. Harvala Mar 2001

A Low Power Application-Specific Integrated Circuit (Asic) Implementation Of Wavelet Transform/Inverse Transform, Daniel N. Harvala

Theses and Dissertations

A unique ASIC was designed implementing the Haar Wavelet transform for image compression/decompression. ASIC operations include performing the Haar wavelet transform on a 512 by 512 square pixel image, preparing the image for transmission by quantizing and thresholding the transformed data, and performing the inverse Haar wavelet transform, returning the original image with only minor degradation. The ASIC is based on an existing four-chip FPGA implementation. Implementing the design using a dedicated ASIC enhances the speed, decreases chip count to a single die, and uses significantly less power compared to the FPGA implementation. A reduction of RAM accesses was realized …

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Weapon System Environmental Life Cycle Cost Methodologies And Models, William H. Kale Iii Mar 2001

Weapon System Environmental Life Cycle Cost Methodologies And Models, William H. Kale Iii

Theses and Dissertations

Major Defense Acquisition Programs (MDAP) cost billions of dollars and have 30 to 50 year life spans. Numerous (federal, state, etc.) laws, Environmental Protection Agency regulations, and Executive Orders have driven DoD to develop and implement significant environmental policies within the past ten to fifteen years. Congressional mandate now requires each MDAP to evaluate its environmental life cycle cost (ELCC) to minimize these costs. This research focuses on the current methodologies and models used to predict and calculate the ELCC of a MDAP. This thesis analyzed the difficulties associated with using ELCC methodologies and models and examined several case studies …

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Utility Of Experimental Design In Automatic Target Recognition Performance Evaluation, James M. Higdon Mar 2001

Utility Of Experimental Design In Automatic Target Recognition Performance Evaluation, James M. Higdon

Theses and Dissertations

This research investigates current practices in test and evaluation of classification algorithms, and recommends improvements. We scrutinize the evaluation of automatic target recognition algorithms and rationalize the potential for improvements in the accepted methodology. We propose improvements through the use of an experimental design approach to testing. We demonstrate the benefits of improvements by simulating algorithm performance data and using both methodologies to generate evaluation results. The simulated data is varied to test the sensitivity of the benefits to a broad set of outcomes. The opportunities for improvement are threefold. First, the current practice of 'one-at-a-time factor variation (only one …

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Influence Of Personality Type And Anonymity On Participation In A Group Support System, Robert E. Hartmann Mar 2001

Influence Of Personality Type And Anonymity On Participation In A Group Support System, Robert E. Hartmann

Theses and Dissertations

A group support system (GSS) uses a combination of networked personal computers, software that collects, manipulates, and aggregates member's individual input, and human facilitation to improve the group decision-making process. A GSS has been promoted as a means of improving the quantity and quality of ideas within a decision-making meeting. Research into GSS has focused on the benefits of providing anonymity to improve participation. Anonymity in a GSS meeting has been offered as a means to improve participation, which in turn improves decision quality. To date this has not been proven through research. In fact, there is conflicting evidence as …

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A Delphi Assessment Of The Digital Rosetta Stone Model, Don M. Kelley Mar 2001

A Delphi Assessment Of The Digital Rosetta Stone Model, Don M. Kelley

Theses and Dissertations

Information that is stored digitally can only be used if it can be retrieved and interpreted. if the methods to retrieve the information are lost, it may be difficult, if not impossible, to recreate them. The knowledge to interpret the bitstream is also at risk. The Digital Rosetta Stone (DRS) Model was developed as a framework for capturing and maintaining the methods necessary to retrieve and display digital information stored on obsolete media or using obsolete software. However, this conceptual model had not yet been assessed by the community of professionals for its practical efficacy. This thesis began the assessment …

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Malicious Hackers: A Framework For Analysis And Case Study, Laura J. Kleen Mar 2001

Malicious Hackers: A Framework For Analysis And Case Study, Laura J. Kleen

Theses and Dissertations

Recent years have seen an increase in the number and severity of Information Operations (IO) attacks upon DoD resources. At a higher level, the US as a whole has come under cyber attack by individuals and groups seeking thrills, monetary gain, publicity for their causes, and myriad other goals. This effort develops a first cut model of individual hacker mentality that can be utilized to improve threat assessment, mitigate Information Assurance (IA) vulnerabilities, and improve risk assessment. Further, it is a first step toward automated characterization of Information Warfare (IW) attacks based upon hacker types. All hackers are not the …

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Wavelet-Based Audio Embedding & Audio/Video Compression, Michael J. Mendenhall Mar 2001

Wavelet-Based Audio Embedding & Audio/Video Compression, Michael J. Mendenhall

Theses and Dissertations

With the decline in military spending, the United States relies heavily on state side support. Communications has never been more important. High-quality audio and video capabilities are a must. Watermarking, traditionally used for copyright protection, is used in a new and exciting way. An efficient wavelet-based watermarking technique embeds audio information into a video signal. Several highly effective compression techniques are applied to compress the resulting audio/video signal in an embedded fashion. This wavelet-based compression algorithm incorporates bit plane coding, first difference coding, and Huffman coding. To demonstrate the potential of this audio embedding audio/video compression system, an audio signal …

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Chromate Content Bias As A Function Of Particle Size In Aircraft Primer Paint Overspray, David B. Novy Mar 2001

Chromate Content Bias As A Function Of Particle Size In Aircraft Primer Paint Overspray, David B. Novy

Theses and Dissertations

Spray painting operations using chromate-containing primer paints produce particles which may expose workers to strontium chromate. Chromate contains hexavalent chromium (Cr(VI)) which is a confirmed human carcinogen. It is suspected that the smaller particles contain disproportionately less Cr(VI) than larger particles. In order to determine if a bias in chromate content exists, paint particles were collected and separated based on particle size and the Cr(VI) concentration was determined. Aviation primer paint from the DeSoto and Deft companies was sprayed in a booth and seven-stage cascade impactors were used to separate particles.

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Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker Mar 2001

Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker

Theses and Dissertations

Subsurface contamination by industrial chemicals is one of the most prevalent and costly environmental problems facing the United States government. This contamination problem must be managed to protect human health and the environment. Two basic strategies are used to deal with subsurface contamination: source removal and contaminant containment. While much cost and performance data are available for individual technologies associated with each of these strategies, there have been very few studies that have examined the benefits of implementing source removal technologies in order to reduce contaminant containment (and hopefully total) costs. This study examines the tradeoff between extent of source …

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Modeling Chlorinated Ethene Removal In The Methanogenic Zone Of Constructed Wetlands: A System Dynamics Approach, Randall L. Roberts Mar 2001

Modeling Chlorinated Ethene Removal In The Methanogenic Zone Of Constructed Wetlands: A System Dynamics Approach, Randall L. Roberts

Theses and Dissertations

The purpose of this study is to gain understanding of the dynamics of the processes that degrade Perchloroethene (PCE) to ethene, within the confines of the methanogenic zone of a constructed wetland. A system dynamics modeling approach is used. This model is focused on determining conditions that will enhance contaminant degradation. The chemical and biological processes within the methanogenic zone of a wetland system are extremely complex and dynamic processes. The model is broken up into three simultaneous processes: dechlorination, methanogenesis, and fermentation. The system behavior of the methanogenic zone can be adequately described by the classical formulations of representative …

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Infosphere Project: An Overview, Calton Pu, Jonathan Walpole Mar 2001

Infosphere Project: An Overview, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

We describe the Infosphere project, which is building the systems software support for information-driven applications such as digital libraries and electronic commerce. The main technical contribution is the Infopipe abstraction to support information flow with quality of service. Using building blocks such as program specialization, software feedback, domain-specific languages, and personalized information filtering, the Infopipe software generates code and manage resources to provide the specified quality of service with support for composition and restructuring.

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A Model For Palladium Catalyzed Destruction Of Chlorinated Ethenes In Contaminated Groundwater, Christopher M. Stoppel Mar 2001

A Model For Palladium Catalyzed Destruction Of Chlorinated Ethenes In Contaminated Groundwater, Christopher M. Stoppel

Theses and Dissertations

Groundwater contamination by chlorinated ethenes is a widespread environmental problem. Conventional remediation technologies have shortcomings that have prompted further research into the development of novel treatment technologies. A palladium/ alumina catalyst in the presence of dissolved molecular hydrogen (referred to hereafter as a PD/H2 system) has been demonstrated to rapidly destroy chlorinated ethene contaminated groundwater. First-order kinetics have been used to model chlorinated ethene destruction in a PD/H2 reactor. However, catalyst deactivation and regeneration are important processes that also need to be modeled in order to better understand their effect on treatment efficiency. This study presents a model …

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Gss Technology As A Moderator Of Influence And Perceived Expertise, Kevin V. Thompson Mar 2001

Gss Technology As A Moderator Of Influence And Perceived Expertise, Kevin V. Thompson

Theses and Dissertations

Group Support System (355) research has found this content and process anonymity influence problem solving groups. However, previous studies report mixed results on how OSS technology changes social influence processes and recognition of expertise which affect group performance. This thesis explored content and process anonymity's affect on influence and perceived expertise using three treatments to derive possible explanations for the mixed results found in previous GSS research. The study developed a theoretical model of influence, perceived expertise, and performance. Using structural equation modeling the study tested the relationships between expertise and participation rates, and overall group performance. An experiment was …

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An Analysis Of Civil Engineer Officer Contingency Training, Rusty J. Vaira Mar 2001

An Analysis Of Civil Engineer Officer Contingency Training, Rusty J. Vaira

Theses and Dissertations

The primary objective of this research was to investigate the current overall civil engineer officer contingency training program and determine if civil engineer officers think it is adequately preparing them to perform in a contingency environment. In accomplishing this objective, this research explored the perceptions that officers have about the contingency training that is available through three primary training programs (Home Station Training, Silver Flag training, and Civil Engineer and Services School training). The overall intent of the author was to gauge how the officers feel about their contingency training and offer some suggestions on how to improve the training. …

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Quantitative Validation Of A Model Of Chlorinated Ethene Natural Attenuation, Harold C. Young Mar 2001

Quantitative Validation Of A Model Of Chlorinated Ethene Natural Attenuation, Harold C. Young

Theses and Dissertations

Chlorinated ethenes are among the most prevalent groundwater contaminants at hazardous waste sites nationwide. In an attempt to manage the risks posed by these contaminants, while controlling costs, monitored natural attenuation (MNA) is being considered as a remediation strategy at many sites. MNA relies on naturally occurring physical, chemical, and biological processes in the subsurface to reduce the risk posed by the contamination. The implementation of MNA, however, requires a detailed understanding of these processes, and how they impact contamination at a particular site. One way to gain this understanding is through contaminant fate and transport modeling. In this study, …

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Electrochemical Impedance Spectroscopy Studies On Inhibitive Performance Of Aluminum Triphosphate Pigment, Yong-Gui Liao, Zhi-Jun Gu, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su Feb 2001

Electrochemical Impedance Spectroscopy Studies On Inhibitive Performance Of Aluminum Triphosphate Pigment, Yong-Gui Liao, Zhi-Jun Gu, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su

Journal of Electrochemistry

The epoxy coatings on A3 steel sheets containing calcite or aluminum triphosphate (AlTP), were investigated by Electrochemical Impedance Spectroscopy (EIS). The results showed that calcite pigment is not an inhibitor, but an extender pigment, and that AlTP pigment can considerably enhance the protective performance of epoxy coating. The triphosphate ion at the interface between the steel substrate and the coating can complex with the corrosion product, such as ferric and ferrous ions, and form a compact protective film which effectively separates the steel substrate from the aggressive media.

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How Can Direct Mthanol Fuel Cell Benefit From Carbonate Media, Lin Zhuang, Yang Wang, Jun-Tao Lu Feb 2001

How Can Direct Mthanol Fuel Cell Benefit From Carbonate Media, Lin Zhuang, Yang Wang, Jun-Tao Lu

Journal of Electrochemistry

The kinetics of methanol oxidation and oxygen reduction in 0.5 mol/L K2CO3 were compared with those in 0.5 mol/L H2SO 4. Experiments revealed that carbonate media could be more beneficial to direct methanol fuel cell(DMFC). Firstly, both electrode reactions show better performance in the carbonate than in the acid; secondly, materials other than noble metals become possible to be used as the anodic and cathodic catalysts; thirdly, the potential dectease caused by methanol crossover could be depressed by using metal oxide catalysts not stable in acid, such as MnO2.

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Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode Ii. Eqcm And In-Situ Ftir Spectroscopic Studies In Acid Media, Guo-Liang Chen, Sheng-Pei Chen, Zhi-You Zhou, Chun-Hua Zhen, Shi-Gang Sun Feb 2001

Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode Ii. Eqcm And In-Situ Ftir Spectroscopic Studies In Acid Media, Guo-Liang Chen, Sheng-Pei Chen, Zhi-You Zhou, Chun-Hua Zhen, Shi-Gang Sun

Journal of Electrochemistry

The adsorption and oxidation of ethanol on nm Pt/GC electrode in acid solutions containing 0.1 mol·L -1 H2SO4 +0.1 mol·L -1 CH3CH2OH was investigated by using cyclic voltammetry, EQCM and in situ FTIR spectroscopy. The experimental results demonstrated that the oxidation of CH3CH2OH is closely relaed to solution acidity and oxygen species on electrode surface; CH3CH2OH was oxidized on nm Pt/GC electrode in acidic media via a dual path reaction mechanism, i.e . CH3CH2OH may be oxidized into CO2 through …

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Michaelis–Menten Kinetics For Enzymatic Depolymerization Of A Linear Polyester Synthesized From Z-Protected Glutamic Acid, R. M. Tadros, Hossein Noureddini, Delmar C. Timm Feb 2001

Michaelis–Menten Kinetics For Enzymatic Depolymerization Of A Linear Polyester Synthesized From Z-Protected Glutamic Acid, R. M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomaterials

A biodegradable polyester resin was polymerized from N-benzyloxycarbonyl-L-glutamic acid and ethylene glycol. Rhizopus delemar lipase was used as a biocatalyst for the rupture of ester bonds during the hydrolysis studies. Depoly-merization was observed to followa Michaelis–Menten mechanism, with the maximumrate of monomer formation dP/dtmax = 1.12 x 10-8 mol/s and the rate constant Km x 2.03 x 10-4 mol. Subject to initial conditions described by the most probable distribution and Michaelis–Menten–type depolymerization rate expressions, population density distribution dynamics of the polymeric molecules that formed the resin were explicitly described using a deterministic approach.

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Semiautomated Skeletonization Of The Pulmonary Arterial Tree In Micro-Ct Images, Christopher C. Hanger, Steven Thomas Haworth, Robert C. Molthen, Christopher A. Dawson Feb 2001

Semiautomated Skeletonization Of The Pulmonary Arterial Tree In Micro-Ct Images, Christopher C. Hanger, Steven Thomas Haworth, Robert C. Molthen, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

We present a simple and robust approach that utilizes planar images at different angular rotations combined with unfiltered back-projection to locate the central axes of the pulmonary arterial tree. Three-dimensional points are selected interactively by the user. The computer calculates a sub- volume unfiltered back-projection orthogonal to the vector connecting the two points and centered on the first point. Because more x-rays are absorbed at the thickest portion of the vessel, in the unfiltered back-projection, the darkest pixel is assumed to be the center of the vessel. The computer replaces this point with the newly computer-calculated point. A second back-projection …

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