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2003

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Articles 301 - 330 of 3319

Full-Text Articles in Physical Sciences and Mathematics

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 195 Bridge On The West Fork Of The White River, Marc Nelson, Wade Cash Nov 2003

Water Quality Sampling, Analysis And Annual Load Determinations For Tss, Nitrogen And Phosphorus At The Washington County Road 195 Bridge On The West Fork Of The White River, Marc Nelson, Wade Cash

Arkansas Water Resources Center Technical Reports

A water quality sampling station was installed at the Washington County Road 195 Bridge on the West Fork of the White River just above the confluence of the three main forks of the Upper White River in December 2001. The Quality Assurance Project Plan (QAPP) was approved by EPA Region Six on March 2002 and sampling was begun at that time. This station is coordinated with a USGS gauging station at the same location. This station was instrumented to collect samples at sufficient intervals across the hydrograph to accurately estimate the flux of total suspended solids, nitrogen and phosphorus into …


2002 Pollutant Loads Kings River Near Berryville, Arkansas, Marc Nelson, Wade Cash Nov 2003

2002 Pollutant Loads Kings River Near Berryville, Arkansas, Marc Nelson, Wade Cash

Arkansas Water Resources Center Technical Reports

An automatic sampler and a USGS gauging station were established in 1998 and water quality sampling was begun in 1999 on the Kings River near Berryville, Arkansas. Continuous stage and discharge measurements and frequent water quality sampling have been used to determine pollutant concentrations and loads in the river. This report presents the results from the sampling and analysis for January 1, 2002 to December 31, 2002.


Fisheries Research Report No. 146 - Catch Composition Of The Western Australian Temperate Demersal Gillnet And Demersal Longline Fisheries, 1994 To 1999, Rory Mcauley, Colin Simpfendorfer Nov 2003

Fisheries Research Report No. 146 - Catch Composition Of The Western Australian Temperate Demersal Gillnet And Demersal Longline Fisheries, 1994 To 1999, Rory Mcauley, Colin Simpfendorfer

Fisheries Research Reports

Catch composition data were collected from Western Australia’s temperate demersal gillnet and demersal longline fisheries, between Eucla and Geraldton, over a five-year period from July 1994 to June 1999. Results were compared to Department of Fisheries catch records compiled from fishers’ monthly catch returns. Discarded bycatch of several species was estimated by bootstrapping their observed catch rates. Dusky shark, Carcharhinus obscurus, gummy shark, Mustelus antarcticus, whiskery shark, Furgaleus macki, and Port Jackson shark, Heterodontus portusjacksoni, were identified as the main components of the fisheries’ catch, however, catches were found to vary regionally. School shark, Galeorhinus galeus, dogfish of the family …


Acid-Base Properties Of Aluminum In A Hardwood Forest Soil (Or: Acid Rain Is Dead…), Chris E. Johnson Nov 2003

Acid-Base Properties Of Aluminum In A Hardwood Forest Soil (Or: Acid Rain Is Dead…), Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.


Geosciences Newsletter- 2003, Department Of Geosciences Nov 2003

Geosciences Newsletter- 2003, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 1, No. 28

  • Dear Alumni and Friends
  • Faculty News
  • Department News
  • Awards and Graduations
  • Alumni News
  • Field Trips
  • Donations


Semantic E-Workflow Composition, Jorge Cardoso, Amit P. Sheth Nov 2003

Semantic E-Workflow Composition, Jorge Cardoso, Amit P. Sheth

Kno.e.sis Publications

Systems and infrastructures are currently being developed to support Web services. The main idea is to encapsulate an organization's functionality within an appropriate interface and advertise it as Web services. While in some cases Web services may be utilized in an isolated form, it is normal to expect Web services to be integrated as part of workflow processes. The composition of workflow processes that model e-service applications differs from the design of traditional workflows, in terms of the number of tasks (Web services) available to the composition process, in their heterogeneity, and in their autonomy. Therefore, two problems need to …


Review Of "Liquid Crystals: Fundamentals" By S. Singh, Peter J. Collings Nov 2003

Review Of "Liquid Crystals: Fundamentals" By S. Singh, Peter J. Collings

Physics & Astronomy Faculty Works

No abstract provided.


Hypsometry, Volume And Physiography Of The Arctic Ocean And Their Paleoceanographic Implications, Martin Jakobsson, Ron Macnab, Arthur Grantz, Yngue Kristoffersen Nov 2003

Hypsometry, Volume And Physiography Of The Arctic Ocean And Their Paleoceanographic Implications, Martin Jakobsson, Ron Macnab, Arthur Grantz, Yngue Kristoffersen

Center for Coastal and Ocean Mapping

Recent analyses of the International Bathymetric Chart of the Arctic Ocean (IBCAO) grid model include: Hypsometry (the distribution of surface area at various depths); ocean volume distribution; and physiographic provinces [Jakobsson 2002; Jakobsson et al., in press]. The present paper summarizes the main results from these recent studies and expands on the paleoceanographic implications for the Arctic Ocean, which in this work is defined as the broad continental shelves of the Barents, Kara, Laptev, East Siberian and Chukchi Seas, the White Sea and the narrow continental shelves of the Beaufort Sea, the Arctic continental margins off the Canadian Arctic Archipelago …


Sorption Of Phosphorus By Soils : How It Is Measured In Western Australia, Michael D A Bolland, D G. Allen, N J. Barrow Nov 2003

Sorption Of Phosphorus By Soils : How It Is Measured In Western Australia, Michael D A Bolland, D G. Allen, N J. Barrow

Bulletins 4000 -

Most soils used for agriculture in Western Australia had insufficient indigenous native phosphorus P for the introduced agricultural plant species used in the region so fertiliser P had to be applied. This bulletin covers how water-soluble P WSP fertilisers are made, and how the P in the fertilisers dissolves and reacts with soil in the year of application and in the years after application, how soils sorb P and procedures and soil tests used to estimate the capacity of soils to sorb P.


Remote Sensing Of Sediment Characteristics By Optimized Echo-Envelope Matching, Daniel D. Sternlicht, Christian De Moustier Nov 2003

Remote Sensing Of Sediment Characteristics By Optimized Echo-Envelope Matching, Daniel D. Sternlicht, Christian De Moustier

Center for Coastal and Ocean Mapping

A sediment geoacoustic parameter estimation technique is described which compares bottom returns, measured by a calibrated monostatic sonar oriented within 15° of vertical and having a 10°–21° beamwidth, with an echo envelope model based on high-frequency (10–100 kHz) incoherent backscattertheory and sediment properties such as: mean grain size, strength, and exponent of the power law characterizing the interface roughness energy density spectrum, and volume scattering coefficient. An average echo envelope matching procedure iterates on the reflection coefficient to match the peak echo amplitude and separate coarse from fine-grain sediments, followed by a global optimization using a combination of simulated annealing …


Using Cesium 137 To Understand Recent In Cave Sedimentation In The Tongass National Forest, Southeast Alaska, William Curry Nov 2003

Using Cesium 137 To Understand Recent In Cave Sedimentation In The Tongass National Forest, Southeast Alaska, William Curry

Masters Theses & Specialist Projects

Removal of vegetation and subsequent erosion in karst regions such as central Kentucky or southeastern Alaska often leads to increased sedimentation in karst features such as caves and dolines. This sedimentation can impact the ground water by altering flow paths and the bio-geochemistry of the karst aquifer itself. Various methodologies have been used to obtain quantitative erosion and sedimentation rates for surface areas in karst and non-karst settings, but few quantitative studies have taken place in caves. The purpose of this study is to examine the effects of timber harvesting and development upon the caves and karst of southeastern Alaska …


Time Dependent Seafloor Acoustic Backscatter (10-100khz), Daniel D. Sternlicht, Christian De Moustier Nov 2003

Time Dependent Seafloor Acoustic Backscatter (10-100khz), Daniel D. Sternlicht, Christian De Moustier

Center for Coastal and Ocean Mapping

A time-dependent model of the acoustic intensity backscattered by the seafloor is described and compared with data from a calibrated, vertically oriented, echo-sounder operating at 33 and 93 kHz. The model incorporates the characteristics of the echo-sounder and transmitted pulse, and the water column spreading and absorption losses. Scattering from the water–sediment interface is predicted using Helmholtz–Kirchhoff theory, parametrized by the mean grain size, the coherent reflection coefficient, and the strength and exponent of a power-law roughness spectrum. The composite roughness approach of Jackson et al. [J. Acoust. Soc. Am. 79, 1410–1422 (1986)], modified for the finite duration of …


Towards (Semi-) Automatic Generation Of Bio-Medical Ontologies, Vipul Kashyap, Cartic Ramakrishnan, Thomas Rindflesch Nov 2003

Towards (Semi-) Automatic Generation Of Bio-Medical Ontologies, Vipul Kashyap, Cartic Ramakrishnan, Thomas Rindflesch

Kno.e.sis Publications

The design and construction of domain specific ontologies and taxonomies requires allocation of huge resources in terms of cost and time. These efforts are human intensive and we need to explore ways of minimizing human involvement and other resources. In the biomedical domain, we seek to leverage resources such as the UMLS1 Metathesaurus and NLP-based applications such as MetaMap2 in conjunction with statistical clustering techniques, to (partially) automate the process. This is expected to be useful to the team involved in developing MeSH and other biomedical taxonomies to identify gaps in the existing taxonomies, and to be able to quickly …


Evidence Of The Zn Vacancy Acting As The Dominant Acceptor In N-Type Zno, F. Tuomisto, V. Ranki, K. Saarinen, David C. Look Nov 2003

Evidence Of The Zn Vacancy Acting As The Dominant Acceptor In N-Type Zno, F. Tuomisto, V. Ranki, K. Saarinen, David C. Look

Physics Faculty Publications

We have used positron annihilation spectroscopy to determine the nature and the concentrations of the open volume defects in as-grown and electron irradiated (Eel=2   MeV, fluence 6×1017   cm-2) ZnO samples. The Zn vacancies are identified at concentrations of [VZn]≃2×1015   cm-3 in the as-grown material and [VZn]≃2×1016   cm-3 in the irradiated ZnO. These concentrations are in very good agreement with the total acceptor density determined by temperature dependent Hall experiments. Thus, the Zn vacancies are dominant acceptors in both as-grown and irradiated ZnO.


Aerobic Denitrification Of Pseudomonas Aeruginosa Monitored By Online Nad(P)H Fluorescence, Fan Chen, Qing Xia, Lu-Kwang Ju Nov 2003

Aerobic Denitrification Of Pseudomonas Aeruginosa Monitored By Online Nad(P)H Fluorescence, Fan Chen, Qing Xia, Lu-Kwang Ju

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Continuous cultures of Pseudomonas aeruginosa (ATCC 9027) maintained at different dissolved oxygen concentrations (DO) were studied for the effects of DO on various culture properties, especially aerobic respiration and denitrification. The DO was varied from 0 mg/liter (completely anoxic conditions) to 1.3 mg/liter and measured with optical sensors that could accurately determine very low DO based on oxygen-quenched luminescence. The strain was found to perform aerobic denitrification; while the specific rate decreased with increasing DO, denitrification persisted at approximately 1/8 of the maximum rate (1.7 mmol/g of cells/h) even at relatively high DO (1 to 1.3 mg/liter). In the presence …


Fortune Cookies, Measurement Error, And Experimental Design, Greogry R. Hancock Nov 2003

Fortune Cookies, Measurement Error, And Experimental Design, Greogry R. Hancock

Journal of Modern Applied Statistical Methods

This article pertains to the theoretical and practical detriments of measurement error in traditional univariate and multivariate experimental design, and points toward modern methods that facilitate greater accuracy in effect size estimates and power in hypothesis testing.


Correcting Publication Bias In Meta-Analysis: A Truncation Approach, Guillermo Montes, Bohdan S. Lotyczewski Nov 2003

Correcting Publication Bias In Meta-Analysis: A Truncation Approach, Guillermo Montes, Bohdan S. Lotyczewski

Journal of Modern Applied Statistical Methods

Meta-analyses are increasingly used to support national policy decision making. The practical implications of publications bias in meta-analysis are discussed. Standard approaches to correct for publication bias require knowledge of the selection mechanism that leads to publication. In this study, an alternative approach is proposed based on Cohen’s corrections for a truncated normal. The approach makes less assumptions, is easy to implement, and performs well in simulations with small samples. The approach is illustrated with two published meta-analyses.


Comparison Of Viral Trajectories In Aids Studies By Using Nonparametric Mixed-Effects Models, Chin-Shang Li, Hua Liang, Ying-Hen Hsieh, Shiing-Jer Twu Nov 2003

Comparison Of Viral Trajectories In Aids Studies By Using Nonparametric Mixed-Effects Models, Chin-Shang Li, Hua Liang, Ying-Hen Hsieh, Shiing-Jer Twu

Journal of Modern Applied Statistical Methods

The efficacy of antiretroviral therapies for human immunodeficiency virus (HIV) infection can be assessed by studying the trajectory of the changing viral load with treatment time, but estimation of viral trajectory parameters by using the implicit function form of linear and nonlinear parametric models can be problematic. Using longitudinal viral load data from a clinical study of HIV-infected patients in Taiwan, we described the viral trajectories by applying a nonparametric mixed-effects model. We were then able to compare the efficacies of highly active antiretroviral therapy (HAART) and conventional therapy by using Young and Bowman’s (1995) test.


Deconstructing Arguments From The Case Against Hypothesis Testing, Shlomo S. Sawilowsky Nov 2003

Deconstructing Arguments From The Case Against Hypothesis Testing, Shlomo S. Sawilowsky

Journal of Modern Applied Statistical Methods

The main purpose of this article is to contest the propositions that (1) hypothesis tests should be abandoned in favor of confidence intervals, and (2) science has not benefited from hypothesis testing. The minor purpose is to propose (1) descriptive statistics, graphics, and effect sizes do not obviate the need for hypothesis testing, (2) significance testing (reporting p values and leaving it to the reader to determine significance) is subjective and outside the realm of the scientific method, and (3) Bayesian and qualitative methods should be used for Bayesian and qualitative research studies, respectively.


Ecotoxicological Research At Dit, Maria Davoren, Colm O'Dowd, Sharon Ni Shuilleabhain Nov 2003

Ecotoxicological Research At Dit, Maria Davoren, Colm O'Dowd, Sharon Ni Shuilleabhain

Articles

The term ecotoxicology first defined by Rene Truhart in 1969, essentially describes the study of the harmful effects of chemicals upon ecosystems.


Statistics Of Transmission In One-Dimensional Disordered Systems: Universal Characteristics Of States In The Fluctuation Tails, Lev I. Deych, Mikhail V. Erementchouk, Alexander A. Lisyansky, Alexey Yamilov, Hui Cao Nov 2003

Statistics Of Transmission In One-Dimensional Disordered Systems: Universal Characteristics Of States In The Fluctuation Tails, Lev I. Deych, Mikhail V. Erementchouk, Alexander A. Lisyansky, Alexey Yamilov, Hui Cao

Physics Faculty Research & Creative Works

We numerically study the distribution function of the conductance (transmission) in the one-dimensional tight-binding Anderson and periodic-on-average superlattice models in the region of fluctuation states where single parameter scaling is not valid. We show that the scaling properties of the distribution function depend upon the relation between the system's length L and the length ls determined by the integral density of states. For long enough systems, L ≫ ls, the distribution can still be described within a new scaling approach based upon the ratio of the localization length lloc and ls. In an intermediate …


Statistical Pronouncements Ii, Shlomo S. Sawilowsky Nov 2003

Statistical Pronouncements Ii, Shlomo S. Sawilowsky

Theoretical and Behavioral Foundations of Education Faculty Publications

No abstract provided.


Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2002), Daniel M. Dauer Nov 2003

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2002), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

A study of the macrobenthic communities of the Elizabeth River watershed was initiated in summer 1999. This report presents the data from the fourth year of sampling in 2002. The three objectives of the Benthic Biological Monitoring Program of the Elizabeth River watershed are: (1) To characterize the health of the tidal waters of the Elizabeth River watershed as indicated by the structure of the benthic communities. ( 2) To conduct trend analyses on long-term data at 14 fixed-point stations to relate temporal trends in the benthic communities to changes in water and/or sediment quality. Trend analyses will …


University Of Nebraska-Lincoln School Of Natural Resources Review: Final Report, December 2003, Michael O'Neill, Phaedra Budy, Stephen Degloria, Ed Kanemasu, Jamie Robertson, Derrel Martin, Anne K. Vidaver, Tylr Naprstek, Donna Woudenberg Nov 2003

University Of Nebraska-Lincoln School Of Natural Resources Review: Final Report, December 2003, Michael O'Neill, Phaedra Budy, Stephen Degloria, Ed Kanemasu, Jamie Robertson, Derrel Martin, Anne K. Vidaver, Tylr Naprstek, Donna Woudenberg

School of Natural Resources: Documents and Reviews

In July 2003, the School of Natural Resource Sciences was merged with the Conservation and Survey Division and the Water Center Nebraska State Survey. This merger produced the School of Natural Resources (hereafter referred to as the "School") in its current form. The University of Nebraska-Lincoln requested a ten-year review of the School's programs and activities. The review was administered by the Cooperative State Research, Education and Extension Service (CSREES) in cooperation with the University of Nebraska-Lincoln's Institute of Agriculture and Natural Resources, the College of Agriculture, and the School.

The review document is divided into nine sections. The first …


A Critical Examination Of The Use Of Preliminary Tests In Two-Sample Tests Of Location, Kimberly T. Perry Nov 2003

A Critical Examination Of The Use Of Preliminary Tests In Two-Sample Tests Of Location, Kimberly T. Perry

Journal of Modern Applied Statistical Methods

This paper explores the appropriateness of testing the equality of two means using either a t test, the Welch test, or the Wilcoxon-Mann-Whitney test for two independent samples based on the results of using two classes of preliminary tests (i.e., tests for population variance equality and symmetry in underlying distributions).


Confidence Intervals For P(X Less Than Y) In The Exponential Case With Common Location Parameter, Ayman Baklizi Nov 2003

Confidence Intervals For P(X Less Than Y) In The Exponential Case With Common Location Parameter, Ayman Baklizi

Journal of Modern Applied Statistical Methods

The problem considered is interval estimation of the stress - strength reliability R = P(Xθ and λ respectively and a common location parameter μ . Several types of asymptotic, approximate and bootstrap intervals are investigated. Performances are investigated using simulation techniques and compared in terms of attainment of the nominal confidence level, symmetry of lower and upper error rates, and expected length. Recommendations concerning their usage are given.


Approximate Bayesian Confidence Intervals For The Variance Of A Gaussian Distribution, Vincent A. R. Camara Nov 2003

Approximate Bayesian Confidence Intervals For The Variance Of A Gaussian Distribution, Vincent A. R. Camara

Journal of Modern Applied Statistical Methods

The aim of the present study is to obtain and compare confidence intervals for the variance of a Gaussian distribution. Considering respectively the square error and the Higgins-Tsokos loss functions, approximate Bayesian confidence intervals for the variance of a normal population are derived. Using normal data and SAS software, the obtained approximate Bayesian confidence intervals will then be compared to the ones obtained with the well known classical method. The Bayesian approach relies only on the observations. It is shown that the proposed approximate Bayesian approach relies only on the observations. The classical method, that uses the Chi-square statistic, does …


A Comparison Of Equivalence Testing In Combination With Hypothesis Testing And Effect Sizes, Christopher J. Mecklin Nov 2003

A Comparison Of Equivalence Testing In Combination With Hypothesis Testing And Effect Sizes, Christopher J. Mecklin

Journal of Modern Applied Statistical Methods

Equivalence testing, an alternative to testing for statistical significance, is little used in educational research. Equivalence testing is useful in situations where the researcher wishes to show that two means are not significantly different. A simulation study assessed the relationships between effect size, sample size, statistical significance, and statistical equivalence.


Theoretical Investigation Of The Surface Vibrational Modes In Germanium Nanocrystals, Shang-Fen Ren, Wei Cheng, Peter Y. Yu Nov 2003

Theoretical Investigation Of The Surface Vibrational Modes In Germanium Nanocrystals, Shang-Fen Ren, Wei Cheng, Peter Y. Yu

Faculty publications – Physics

We have used a microscopic lattice dynamical model to study phonon modes in germanium (Ge) NC with size varying between 47 to 7289 atoms (diametersimilar to6.8 nm). By separating these atoms into bulk and surface atoms we have found that surface modes can exist in Ge NC both at low frequencies (<50>cm(-1)) and at high frequency (similar to260 cm(-1)). The latter mode is a resonant mode which occurs in the "pseudogap" between the acoustic and optical phonon branches in bulk Ge. From the low frequency surface modes we have been able to reconstruct the spheroidal and torsional Lamb modes …


Melanoma And Seborrheic Keratosis Differentiation Using Texture Features, Srinivas V. Deshabhoina, Scott E. Umbaugh, William V. Stoecker, Randy Hays Moss, Subhashini K. Srinivasan Nov 2003

Melanoma And Seborrheic Keratosis Differentiation Using Texture Features, Srinivas V. Deshabhoina, Scott E. Umbaugh, William V. Stoecker, Randy Hays Moss, Subhashini K. Srinivasan

Chemistry Faculty Research & Creative Works

Purpose: To explore texture features in two-dimensional images to differentiate seborrheic keratosis from melanoma.

Methods: A systematic approach to consistent classification of skin tumors is described. Texture features, based on the second-order histogram, were used to identify the features or a combination of features that could consistently differentiate a malignant skin tumor (melanoma) from a benign one (seborrheic keratosis). Two hundred and seventy-one skin tumor images were separated into training and test sets for accuracy and consistency. Automatic induction was applied to generate classification rules. Data analysis and modeling tools were used to gain further insight into the feature space. …