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1999

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Full-Text Articles in Physical Sciences and Mathematics

Piezoelectric And Pyroelectric Properties Of Ferroelectric Langmuir-Blodgett Polymer Films, A.V. Bune, Chuanxing Zhu, Stephen Ducharme, L.M. Blinov, V.M. Fridkin, S.P. Palto, N.N. Petukhova, S.G. Yudin Jun 1999

Piezoelectric And Pyroelectric Properties Of Ferroelectric Langmuir-Blodgett Polymer Films, A.V. Bune, Chuanxing Zhu, Stephen Ducharme, L.M. Blinov, V.M. Fridkin, S.P. Palto, N.N. Petukhova, S.G. Yudin

Stephen Ducharme Publications

The piezoelectric and pyroelectric responses of ferroelectric Langmuir–Blodgett polymer films are less than the largest values measured with bulk films of the same composition. The films of the crystalline copolymer poly(vinylidene fluoride trifluoroethylene) fabricated by the Langmuir–Blodgett technique are 30 ML thick (15 nm) and are highly crystalline and oriented with polarization perpendicular to the film. Both piezoelectric and pyroelectric measurements show reversible ferroelectric switching. The films are suitable for use in pyroelectric infrared imaging and in piezoelectric acoustic transducers.


Interactions Between Bicrystal Josephson Junctions In A Multilayer Structure, H.Q. Li, R.H. Ono, L.R. Vale, D.A. Rudman, Sy_Hwang Liou Jun 1999

Interactions Between Bicrystal Josephson Junctions In A Multilayer Structure, H.Q. Li, R.H. Ono, L.R. Vale, D.A. Rudman, Sy_Hwang Liou

Sy-Hwang Liou Publications

We have fabricate and studied a variety of devices based on stacked YBa2Cu3Ox bicrystal Josephson junctions in a multilayer structure. The proximity of the junctions in the two layers produces a large number of effects based on interactions between the junctions. Voltage locking and current locking were observed in the stacked junctions. The voltage locking is due to the ac path provided by a SrTiO3 layer between the stacked junctions. The current locking is likely the result of a Josephson vortex interaction.


A Comprehensive Approach For Evaluation Of Groundwater Vulnerability To Contamination, Shafiul H. Chowdhury Jun 1999

A Comprehensive Approach For Evaluation Of Groundwater Vulnerability To Contamination, Shafiul H. Chowdhury

Dissertations

Groundwater vulnerability to contamination from surface sources was evaluated for Nottawa Creek Watershed, Calhoun County Michigan using AQUIPRO and DRASTIC vulnerability methods. A geographic information system (GIS) was used to analyze and map the data. Forty groundwater samples were collected following a statistical sampling protocol from private wells. Samples were analyzed for nitrate-N and atrazine. Atrazine was not detected (detection limit 0.1 ppb) in any of the samples. Five samples contained detectable nitrate-N (detection limit 0.05 mg/L). Due to insufficient chemical data, the relative AQUIPRO and DRASTIC vulnerability scores could not be compared with the frequency of occurrences o f …


Considerations For An Effective Telecommunications-Use Policy, Michael E. Whitman, Anthony M. Townsend, Robert J. Aalberts Jun 1999

Considerations For An Effective Telecommunications-Use Policy, Michael E. Whitman, Anthony M. Townsend, Robert J. Aalberts

Faculty Articles

Recent changes in federal telecommunications legislation have underscored the importance of an up-to-date and effective telecommunications-use policy in business organizations. With the proliferation of the Internet, intranets, and email as commonplace business tools, the potential for misuse and subsequent liability has become an increasing concern. Even though the recent Supreme Court decision struck down the obscenity provisions of the Communications Decency Act (CDA), it left intact legislation that effectively mandates development of a sound telecommunications-use policy. In addition to potential liability for systems misuse, organizations have also had to address issues of individual employee privacy within the new systems.

This …


Comment On "Relativistic Correction Of The Generalized Oscillator Strength Sum Rules", P.T. Leung, Scott M. Cohen Jun 1999

Comment On "Relativistic Correction Of The Generalized Oscillator Strength Sum Rules", P.T. Leung, Scott M. Cohen

Physics Faculty Publications and Presentations

Romero and Aucar [Phys. Rev. A 57, 2212 (1998)] have found a vanishing result for the relativistic correction to the dipole sum rule ∆S1 for a one-electron system. They have given a result for the dipole sum rule ∆S2 as well. We argue that these results are both incorrect and show explicitly that their approach yields a nonvanishing result for ∆S1. The corrected result is in agreement with that which we have obtained in a recent paper, in which we present explicit expressions for ∆S1, ∆S2, and several other more general sum rules.


Investigating Measures For Pairwise Document Similarity, Jeffrey D. Isaacs Jun 1999

Investigating Measures For Pairwise Document Similarity, Jeffrey D. Isaacs

Dartmouth College Undergraduate Theses

The need for a more effective similarity measure is growing as a result of the astonishing amount of information being placed online. Most existing similarity measures are defined by empirically derived formulas and cannot easily be extended to new applications. We present a pairwise document similarity measure based on Information Theory, and present corpus dependent and independent applications of this measure. When ranked with existing similarity measures over TREC FBIS data, our corpus dependent information theoretic similarity measure ranked first.


Improved Computer Detection And Mapping Of Cerebral Oxygenation, David H. Kung Jun 1999

Improved Computer Detection And Mapping Of Cerebral Oxygenation, David H. Kung

Dartmouth College Undergraduate Theses

Near-infrared (NIR) optical image reconstruction that incorporates blood oxygen level dependant (BOLD) magnetic resonance imaging has the potential to improve both quantifiable measurement of oxygenation and the spatial resolution involved in such mapping. My thesis continues some preliminary work in this area through development of an analytic diffusion parameter estimation algorithm for use with a NIR imaging array and development of a finite element mesh utility to read a priori BOLD images and tag them with property elements for NIR image resolution improvement.


Fast Out-Of-Core Sorting On Parallel Disk Systems, Matthew D. Pearson Jun 1999

Fast Out-Of-Core Sorting On Parallel Disk Systems, Matthew D. Pearson

Dartmouth College Undergraduate Theses

This paper discusses our implementation of Rajasekaran's (l,m)-mergesort algorithm (LMM) for sorting on parallel disks. LMM is asymptotically optimal for large problems and has the additional advantage of a low constant in its I/O complexity. Our implementation is written in C using the ViC* I/O API for parallel disk systems. We compare the performance of LMM to that of the C library function qsort on a DEC Alpha server. qsort makes a good benchmark because it is fast and performs comparatively well under demand paging. Since qsort fails when the swap disk fills up, we can only compare these algorithms …


Sketch-Based Image Queries In Topographic Databases, James Carswell Jun 1999

Sketch-Based Image Queries In Topographic Databases, James Carswell

Articles

In this paper we present the development of a system prototype for sketch-based queries for the content-based retrieval of digital images from topographic databases. We discuss our overall strategy and associated algorithmic and implementation aspects, and present associated database design issues. The query tools devised in this research are employing user-provided sketches of the shape and spatial configuration of the object(s) which should appear in the images to be retrieved. Our matching tool is inspired by least-squares matching (lsm), and represents an extension of lsm to function with a variety of raster representations. Our strategy makes use of a hierarchical …


Scan-It: A Computer Vision Model Motivated By Human Physiology And Behavior, John G. Keller Jun 1999

Scan-It: A Computer Vision Model Motivated By Human Physiology And Behavior, John G. Keller

Theses and Dissertations

This dissertation details the development of a new computational vision model motivated by physiological and behavioral aspects of the human visual system. Using this model, intensity features within an artificial visual field of view are extracted and transformed into a simulated cortical representation, and a saccadic guidance system scans this field of view over an object within an image to memorize that object. The object representation is thus stored as a sequence of feature matrices describing sub-regions of the object. A new image can then be searched for the object (possibly scaled and rotated), where evidence of its presence is …


Period-Doubling Behavior In Frontal Polymerization Of Multifunctional Acrylates, Jonathan Masere, Felicia Stewart, Timothy Meehan, John A. Pojman Jun 1999

Period-Doubling Behavior In Frontal Polymerization Of Multifunctional Acrylates, Jonathan Masere, Felicia Stewart, Timothy Meehan, John A. Pojman

Faculty Publications

Front dynamics in the frontal polymerization of two multifunctional acrylate monomers, 1,6-hexanediol diacrylate (HDDA) and trimethylolpropane ethoxylate triacrylate (TMPTA), with Lupersol 231 [1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane] as the initiator, are studied. In most frontal polymerization systems, the dynamics are associated with a planar front propagating through the sample. However, in some cases, front behavior can be altered: the front becomes nonplanar characterized by complex patterns like spin modes and pulsations. To determine how these periodic and aperiodic modes arise, reactant solutions consisting of HDDA diluted with diethyl phthalate (DEP) and TMPTA diluted with dimethyl sulfoxide (DMSO) were used in the study. …


Final Environmental Impact Statement: Ferron Natural Gas Project, United States Department Of The Interior, Bureau Of Land Management, Utah, Usda Forest Service, Utah Division Of Oil, Gas, And Mining Jun 1999

Final Environmental Impact Statement: Ferron Natural Gas Project, United States Department Of The Interior, Bureau Of Land Management, Utah, Usda Forest Service, Utah Division Of Oil, Gas, And Mining

Elusive Documents

Anadarko Petroleum Corporation, Chandler and Associates, LLC, and Texaco Exploration and Production, Inc. propose to develop two separate areas northeast and southwest of Price, Utah and extract natural gas. Questar Pipeline Company proposes to develop a new natural gas transmission pipeline as part of the Proposed Action. With the pipeline corridor, the Proposed Action encompasses a total of about 111 ,781 acres. The developments would involve drilling a maximum of 285 natural gas wells on Federal, State and private lands, constructing roads and gathering pipelines for natural gas and produced water, drilling wells for disposing of produced water, and construction …


Dynamics Of Formation Of Soliton Conductivity In A 2 D-Array Of Linear Chains Containing Commensurate Charge Density Waves Near The Contact With A Normal Metal, Yuriy V. Pershin Dr, Alexander S. Rozhavsky Jun 1999

Dynamics Of Formation Of Soliton Conductivity In A 2 D-Array Of Linear Chains Containing Commensurate Charge Density Waves Near The Contact With A Normal Metal, Yuriy V. Pershin Dr, Alexander S. Rozhavsky

Faculty Publications

We make a numerical study of the conversion of conduction electrons into charge density wave (CDW) topological solitons at the interface between a normal metal and a 2D-array of the CDW-carrying linear chains. The interplay of commensurability potential, interchain interaction, and electric field on the dynamics of soliton formation is studied. When the interchain interaction exceeds the commensurability energy, the dynamic mechanism of creation of fractionally charged solitons near the contact is suppressed and specific contact nonlinearity in transport current is not observed.


Multiscale Image Registration Using Scale Trace Correlation, Bruce B. Hansen, Bryan S. Morse Jun 1999

Multiscale Image Registration Using Scale Trace Correlation, Bruce B. Hansen, Bryan S. Morse

Faculty Publications

This paper presents a method for registering images at different magnifications (scales) by treating the problem not only as one of scaling the image coordinates but also as one inherently involving multiresolution information. While some existing methods for multiresolution registration do consider the way the resolution (scale) affects the image, they often consider the image one scale at a time, using geometric properties within that scale. Others use multiscale information, usually to produce more robust results, but only to register same-magnification images (e.g., stereo). A scale trace is the set of values that a single pixel takes on as magnification …


Toboggan-Based Intelligent Scissors With A Four-Parameter Edge Model, William A. Barrett, Eric N. Mortensen Jun 1999

Toboggan-Based Intelligent Scissors With A Four-Parameter Edge Model, William A. Barrett, Eric N. Mortensen

Faculty Publications

Intelligent Scissors is an interactive image segmentation tool that allows a user to select piece-wise globally optimal contour segments that correspond to a desired object boundary. We present a new and faster method of computing the optimal path by over-segmenting the image using tobogganing and then imposing a weighted planar graph on top of the resulting region boundaries. The resulting region-based graph is many times smaller than the previous pixel-based graph, thus providing faster graph searches and immediate user interaction. Further, tobogganing provides an new systematic and predictable framework for computing edge model parameters, allowing subpixel localization as well as …


Removal Of Trace Contaminants From Wastewater Effluents Using Local Adsorbents, Kasim Ghulam Haider Ghulam Jun 1999

Removal Of Trace Contaminants From Wastewater Effluents Using Local Adsorbents, Kasim Ghulam Haider Ghulam

Theses

Wastewater reclamation must ensure removal of residual pollutants to a high degree so as to make the water acceptable for the designated reuse. There has been a growing interest worldwide to employ cost-effective treatment methods for polishing secondary treatment wastewater effluents. Carbon adsorption has proved to be an effective method for effluent polishing but treatment costs are relatively high.

AI-Ain wastewater treatment plant at Zakher has a design capacity of 54,000 m3/day and incorporates preliminary treatment, followed by extended aeration and dual-media filtration for effluent polishing before water reuse in irrigation. The chemical quality of the treated effluent …


Growth And Performance Of Some Forage And Landscape Species Directly Irrigated With Saline Water, Mohammed Abdul Muhsen Ali Salem Jun 1999

Growth And Performance Of Some Forage And Landscape Species Directly Irrigated With Saline Water, Mohammed Abdul Muhsen Ali Salem

Theses

This work aimed to study the growth and physiological performance of SIX forage and

landscape species grown in Nahshalah farm , Zayed International Agricultural and Environmental Research Program Among these species 4 mangrove plants were first Introduced to U. A. E cli mate and soils In addition, Acacia ampliceps and Atriplex amnicola The study covered 1- 7 years plants were irrigated With 25 ppt . Saline water. The study investigated also the changes in the soil chemical characteristics and mineral composition during the 1 -9 years direct irrigation with saline water

The growth performance was measured based on the sufficient …


Effect Of Culturing Time And Hormonal Combinations On Organogenesis Of Date Palm (Phoenix Dactylifera L., Cv. Khnazi) In Vitro, Helal Homaid S. Al-Kaabi Jun 1999

Effect Of Culturing Time And Hormonal Combinations On Organogenesis Of Date Palm (Phoenix Dactylifera L., Cv. Khnazi) In Vitro, Helal Homaid S. Al-Kaabi

Theses

Date palm (Phoenix dactylifera L.) monocotyledon dioecious tree is one of the most important fruit crop trees in the Arabian Gulf region in general and in the UAE in particular.

Date palm is propagated sexually by seeds or vegetative by offshoots. Seed propagation is not appropriate for commercial production because of the high genetic heterozygosity, which resulted in not true-to-type male and female seedlings. The vegetative propagation utilizing offshoots is slow and inefficient for rapidly growing demands of the date industry. Therefore, it seems essential to use plant tissue culture techniques for propagating and producing date palms.

The present …


Methodology For Integrating The Scenario Databases Of Simulation Systems, Emilia M. Colonese Jun 1999

Methodology For Integrating The Scenario Databases Of Simulation Systems, Emilia M. Colonese

Theses and Dissertations

The use of many different simulation systems by the United States Department of Defense has resulted in many different scenario data representations contained in heterogeneous databases. These heterogeneous databases all represent the same data concept, but have different semantics due to intrinsic variations among the data models. In this research, I describe a unified scenario database to allow interoperability and reuse of the scenario data components while avoiding the problems of data redundancy. Using the object oriented approach, the data and schema of the scenario databases, represented in an object oriented model, are integrated into a global database also represented …


Estimation And Goodness-Of-Fit In The Case Of Randomly Censored Lifetime Data, David M. Reineke Jun 1999

Estimation And Goodness-Of-Fit In The Case Of Randomly Censored Lifetime Data, David M. Reineke

Theses and Dissertations

A new continuous distribution function estimator for randomly censored data is developed, discussed, and compared to existing estimators. Minimum distance estimation is shown to be effective in estimating Weibull location parameters when random censoring is present. A method of estimating all 3 parameters of the 3-parameter Weibull distribution using a combination of minimum distance and maximum likelihood is also given. Cramer-von Mises and Anderson-Darling goodness-of-fit test statistics are modified to measure the discrepancy between the maximum likelihood estimate and the Kaplan-Meier product-limit estimate of the distribution function of the random variable of interest. These modified test statistics are used to …


Quality Assurance And The Scientific Method, Ray T. Sterner Jun 1999

Quality Assurance And The Scientific Method, Ray T. Sterner

United States Department of Agriculture Wildlife Services: Staff Publications

As all RMRCSQA members know, during the 1980s the Environmental Protection Agency (EPA) and the Food a d Drug Administration (FDA) implemented 40 Code of Federal Regulations (CFR) Parts 160/792 and 21 CFR Part 58, respectively. These regulations outlined GLPs for data data collections needed to register pesticides, toxic substances, and drugs in the U.S.; QA concepts fix study oversight Were also described in these parts (see Sterner and Fagerstone, 1997). What you may not have considered is the relationship of these regulations to the scientific method.


The John Muir Newsletter, Summer 1999, The John Muir Center For Regional Studies Jun 1999

The John Muir Newsletter, Summer 1999, The John Muir Center For Regional Studies

Muir Center Newsletters (1981-2015)

NEW Reconstructing John Muir's First Public Lecture, Sacramento, 1876 by Steve Pauly, Pleasant Hill, California (Editor's Note: This is the third section of Steve Mauley's article which began with the Winter issue.) rock about two miles west of Lake Tenaya has a train of boulders derived from it. The boulders are scattered along a level ridge, where they have not ben disturbed in any appreciable degree since they came to rest toward the close of a glacial period. An examination of the rock proves conclusively that not only were they - rnany of which are twelve feet in diameter - …


Influence Of Nitrogen Rate And Sampling Date On Soil Analysis Values Of Highbush Blueberries, John R. Clark, Ronald W. Mcnew, Richard C. Maples Jun 1999

Influence Of Nitrogen Rate And Sampling Date On Soil Analysis Values Of Highbush Blueberries, John R. Clark, Ronald W. Mcnew, Richard C. Maples

Research Reports and Research Bulletins

Three studies were conducted on nitrogen (N) fertilization effects on soil of highbush blueberries in Arkansas. Objectives included: 1) determination of varying N rate effects on the standard soil analysis variables, 2) determination of date of soil sampling effects on soil analyses, 3) evaluation of the interactions of N rate and time of sampling, and 4) determination of changes in soil content over years. This research was done in two of the more important highbush blueberry production areas in Arkansas: the Arkansas River Valley where blueberries are grown on sandy loam soils, and northwest Arkansas where production is more common …


Parallel Digital Signal Processing On A Network Of Personal Computers Case Study: Space-Time Adaptive Processing, Fernando Silva Jun 1999

Parallel Digital Signal Processing On A Network Of Personal Computers Case Study: Space-Time Adaptive Processing, Fernando Silva

Theses and Dissertations

Network based parallel computing using personal computers is currently a popular choice for concurrent scientific computing. This work evaluates the capabilities and the performance of the AFIT Bimodal Cluster (ABC); a heterogeneous cluster of PCs connected by switched fast Ethernet and using MPICH 1.1 for interprocess communication for parallel digital signal processing using Space Time Adaptive Processing (STAP) as the case study. The MITRE RT_STAP Benchmark version 1.1 is ported and executed on the ABC, as well as on a cluster of six Sun SPARC workstations connected by a Myrinet network (the AFIT NOW), and on a IBM SP for …


Complete View Of Stark Wave-Packet Evolution, M. B. Campbell, Thomas J. Bensky, Robert R. Jones Jun 1999

Complete View Of Stark Wave-Packet Evolution, M. B. Campbell, Thomas J. Bensky, Robert R. Jones

Physics

Picosecond laser pulses have been used to produce Rydberg wave packets in calcium atoms in the presence of a strong static electric field. The dynamics of the Stark wave packets have been observed by measuring the momentum-space probability distribution as a function of time. The full precession of the electronic orbital angular momentum, the appearance of a large-amplitude, linear oscillation of the electronic dipole moment, and a pronounced, periodic up-down asymmetry in the momentum distribution are all observed directly.


Two Algorithms For Performing Multidimensional, Multiprocessor, Out-Of-Core Ffts, Lauren M. Baptist Jun 1999

Two Algorithms For Performing Multidimensional, Multiprocessor, Out-Of-Core Ffts, Lauren M. Baptist

Dartmouth College Undergraduate Theses

We show two algorithms for computing multidimensional Fast Fourier Transforms (FFTs) on a multiprocessor system with distributed memory when problem sizes are so large that the data do not fit in the memory of the entire system. Instead, data reside on a parallel disk system and are brought into memory in sections. We use the Parallel Disk Model for implementation and analysis. The first method is a straightforward out-of-core variant of a well-known method for in-core, multidimensional FFTs. It performs 1-dimensional FFT computations on each dimension in turn. This method is easy to generalize to any number of dimensions, and …


Evolution Of Recurrent Cascade Correlation Networks With Ditributed Collaborative Species, Ghada Nasr Aly Jun 1999

Evolution Of Recurrent Cascade Correlation Networks With Ditributed Collaborative Species, Ghada Nasr Aly

Archived Theses and Dissertations

No abstract provided.


Routing And Caching Mechanisms For Mobile Ip Networks, Baher Ali Esmat Jun 1999

Routing And Caching Mechanisms For Mobile Ip Networks, Baher Ali Esmat

Archived Theses and Dissertations

No abstract provided.


Visual Constraint Programming Environment For Configuration Problems, Rania A/Hamid El Sayed Jun 1999

Visual Constraint Programming Environment For Configuration Problems, Rania A/Hamid El Sayed

Archived Theses and Dissertations

No abstract provided.


Parallel Dassf Discrete-Event Simulation Without Shared Memory, James D. Chalfant Jun 1999

Parallel Dassf Discrete-Event Simulation Without Shared Memory, James D. Chalfant

Dartmouth College Undergraduate Theses

The Dartmouth implementation of the Scalable Simulation Framework (DaSSF) is a discrete-event simulator used primarily in the simulation of networks. It achieves high performance through parallel processing. DaSSF 1.22 requires shared memory between all processors in order to operate. This limits the number of processors available and the hardware platforms that can exploit parallelism. We are interested in extending parallel DaSSF operation to architectures without shared memory. We explore the requirements of this by implementing parallel DaSSF using MPI as the sole form of interaction between processors. The approaches used to achieve this can be abstracted and applied to the …