Physical Sciences and Mathematics Commons^™

Assessing The Performance Of Closed-Form Approximations To The Reml Estimator Of Heritability, Brent D. Burch, Ian R. Harris

Conference on Applied Statistics in Agriculture

For many researchers the restricted maximum likelihood (REML) method of estimation is the procedure of choice for estimating heritability. In most applications the REML estimate can only be obtained via an iterative method. In some cases the algorithm used to compute the REML estimate may be slow or fail to converge. These predicaments have provided the motivation to develop closed-form approximations to the REML estimator of heritability in mixed linear models having two variance components. These estimators are compared to the REML estimator by considering their large and small sample properties. We provide guidance on how to select the closed-form …

Comparing Binomial Bootstrap And Bayesian Estimation Methods In Assessing The Agreement Between Classified Images And Ground Truth Data., Bahman Shafii, William J. Price

Conference on Applied Statistics in Agriculture

The degree of agreement between classification and ground truth in remotely sensed data is often quantified with an error matrix and summarized using agreement measures such as Cohen's kappa. In the case of ground truth however, the kappa statistic can be shown to be a transformation of the marginal proportions commonly referred to as omissional and commissional error rates. A more meaningful statistical interpretation of remote sensing results and less ambiguous conclusions can be obtained via direct utilization of these measures. Several estimation techniques have been suggested for these marginal proportions. In this study, we will develop the exact binomial, …

Papadakis Nearest Neighbor Analysis Of Yield In Agricultural Experiments, Radha G. Mohanty

Conference on Applied Statistics in Agriculture

Papadakis analysis, originally proposed by Papadakis in 1937 belongs to a larger class of methodologies called the nearest neighbor analysis which is primarily based on the fact that plots in close proximity ("neighbors") are exposed to similar environmental conditions and therefore, for a given plot, information from its neighboring plots could be used for adjustment of its response for spatial variability. The basic theory behind the application of Papadakis methodology to field trials is relatively simple. It is based on an analysis of covariance where the covariate is an index of fertility environment), and the response is some observable trait …

Enumeration Of Mixed Linear Models And A Sas Macro For Computation Of Confidence Intervals For Variance Components, Ann Hess, Hari Iyer

Conference on Applied Statistics in Agriculture

It is well known that there is a one-to-one correspondence between fixed effects ANOVA models involving both crossed and nested factors, and combinatorial objects called "posets". The enumeration of nonisomorphic posets is an interesting and nontrivial combinatorial problem for which answers are available for posets of order 14 or less, i.e. for fixed effects ANOVA models with 14 or fewer factors. Such an enumeration problem does not appear to have been considered for mixed effects models. In this paper we study this problem and obtain a list of nonisomorphic mixed effects models involving five or fewer factors. For instance, it …

A Statistical Model Using Reference Evapotranspiration And Weather Data To Predict The Economic Optimal Irrigation Level For Corn Production In The Texas Panhandle, W. Arden Colette, Clay Robinson, Lal Khan Almas

Conference on Applied Statistics in Agriculture

Corn yield and evapotranspiration (ET) data obtained from weighing lysimeters is accumulated from nine experiments over six years and used to estimate a response function. The quadratic response function of corn yield as a function of water use by the plants indicates that yield increases at a decreasing rate as ET increases. Extending the analysis to water application data by commercial producers in a thirteen county area in the Texas Panhandle provides a response function of yield as a function of water application to meet ET needs. The best estimate of the relationship is a quadratic function. The response function …

Simulation Study Of Spatial-Poisson Data Assessing Inclusion Of Spatial Correlation And Non-Normality In The Analysis, Rebecca A. Hensberry, David B. Marx, Daryl Travnicek, Stephen Kachman

Conference on Applied Statistics in Agriculture

Spatial correlation and non-normality in agricultural, geological, or environmental settings can have a significant effect on the accuracy of the results obtained in the statistical analyses. Generalized linear mixed models, spatial models, and generalized linear models were compared in order to assess how critical the inclusion of non-normality and spatial correlation is to the analysis. Spatially correlated data with a Poisson distribution were generated in a completely randomized design (CRD) with 2 treatments and 18 repetitions. Four analyses: spatial Poisson, non-spatial Poisson, spatial normal, and non-spatial normal, were conducted on the simulated data to compare their power functions. The degree …

From Farms To Pharmaceuticals: Multiple Comparisons Enters The 21st Century, Peter H. Westfall

Conference on Applied Statistics in Agriculture

The subject of multiple comparisons has early roots in statistical methods that were applied in agricultural sciences, often using simple methods with questionable properties popularized by no less than R.A. Fisher. More recently, problems of multiple comparisons have surfaced in the pharmaceutical sciences. In the extremely competitive and highly regulated pharmaceutical environment, it has become essential to take multiple comparisons more seriously, and to use more sophisticated methods. In this paper I describe the need for considering multiple comparisons, with special reference to the recent shift in approach to multiple comparisons in the pharmaceutical industry. I also offer speculations about …

Editor's Preface, Table Of Contents, And List Of Attendees, George A. Milliken

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented in the thirteenth annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, April 29-May 1, 2001.

Monitoring Relative Abundance Of American Shad In Virginia’S Rivers 2000 Annual Report, John E. Olney, John M. Hoenig

Reports

Since the moratorium, there have been no monitoring programs that provided direct assessment of stock recovery until this project began in 1998. The ban on in-river fishing in Virginia remained in effect, creating a dilemma for managers who needed reliable information in order to make a rational decision on when the in-river ban could safely be lifted. To address this deficiency, we proposed a method of scientific monitoring to estimate catch rates relative to those recorded before the prohibition of in-river fishing in 1994. This monitoring program began in 1998 and consisted of sampling techniques and locations that were consistent …

Some Problem In Homogenization., M. Rajesh Dr.

Doctoral Theses

No abstract provided.

Engineering Production Function And Choice Of Technique., N. S. S. Narayana Dr.

Doctoral Theses

This study deala wi th the selection of technological al ternaid ves of production, a problom referred to as choice of techninues" in ecommie theory. Selection of an appropriate technique (or a technolo gical al ternative) haa to be Bede with ro spe et to speci fied objectives and avail phle reDurces. Selection of proper techniques from smong many avall ablo el ternatives ha boen one of the min tasks whilu planni ng for econonio development. Generally develooping co untries like India are handi capped by problema of BCerci ty of on-lebour reaources, abundant labour force, lini ted foreign-aid, 1inited …

Energy Gaps In “Metallic” Single-Walled Carbon Nanotubes, Min Ouyang, Jin-Lin Huang, Chin Li Cheung, Charles Lieber

Barry Chin Li Cheung Publications

Metallic single-walled carbon nanotubes have been proposed to be good one-dimensional conductors. However, the finite curvature of the graphene sheet that forms the nanotubes and the broken symmetry due to the local environment may modify their electronic properties. We used low-temperature atomically resolved scanning tunneling microscopy to investigate zigzag and armchair nanotubes, both thought to be metallic. “Metallic” zigzag nanotubes were found to have energy gaps with magnitudes that depend inversely on the square of the tube radius, whereas isolated armchair tubes do not have energy gaps. Additionally, armchair nanotubes packed in bundles have pseudogaps, which exhibit an inverse dependence …

Introduced Wildlife Of Oregon And Washington , Gary W. Witmer, Jeffrey C. Lewis

United States Department of Agriculture Wildlife Services: Staff Publications

Each species of wildlife occurs as part of an ecosystem, interacting in many ways with other plant and animal species in that system as well as with the abiotic components such as soil, air, water, and other substrates. The array of wildlife species around the globe has been shaped by geological and climatological events as well as by eons of evolution and natural selection. Species have come and gone and those remaining have, in most cases, co-evolved or co-adapted with many other species so that relatively stable, and often complex, relationships exist. Usually, a great many niches have been carved …

The Vacuum Excitation And Squeezing Properties Of Two Quantum Oscillators With Delta-Kicked Interactions, J Y. Ji, David Peak

All Physics Faculty Publications

The vacuum excitation and squeezing of two harmonic oscillators with delta-kicked interactions for four types of elementary coupling are studied. The exact quantum motion for the Heisenberg operators and the explicit form of squeezing operators are found. The variances are calculated to study the squeezing properties for position, momentum and generalized quadrature operators.

Velocity Field Distributions Due To Ideal Line Vortices, Thomas D. Levi, David C. Montgomery

Dartmouth Scholarship

We evaluate numerically the velocity field distributions produced by a bounded, two-dimensional fluid model consisting of a collection of parallel ideal line vortices. We sample at many spatial points inside a rigid circular boundary. We focus on “nearest-neighbor” contributions that result from vortices that fall (randomly) very close to the spatial points where the velocity is being sampled. We confirm that these events lead to a non-Gaussian high-velocity “tail” on an otherwise Gaussian distribution function for the Eulerian velocity field. We also investigate the behavior of distributions that do not have equilibrium mean-field probability distributions that are uniform inside the …

A Greek Cross Dodecaphenylene: Sparteine-Mediated Asymmetric Synthesis Of Chiral D2-Symmetric Π-Conjugated Tetra-O-Phenylenes, Andrzej Rajca, Hua Wang, Pavel Bolshov, Suchada Rajca

Andrzej Rajca Publications

The asymmetric synthesis of a chiral, nonracemic π-conjugated system with D₂ point group of symmetry, dodecaphenylene 4 is described. In the key step, (−)-sparteine- and Cu(II)-mediated oxidation of 2,2′-dilithio-1,1′-biaryls in ether gives the corresponding dimers, tetra-o-phenylenes, in 80% isolated yields and 50–60% ee’s. X-Ray crystallography confirms the structure of rac-4 and its molecular shape of a Greek cross. The torsional angles between the benzene rings in the tetra-o-phenylene core of rac-4 are in the 56.5–71.0° range. However, CD and UV spectra of 4 in CH₂Cl₂ are consistent with significant conjugation between the …

Marine Biological Monitoring In Broward County, Florida: Year 1 Annual Report, David S. Gilliam, Richard E. Dodge, Richard E. Spieler, Susan L. Thornton, Lance K. B. Jordan

Marine & Environmental Sciences Faculty Reports

No abstract provided.

Quasi-Model-Independent Search For New High PT Physics At D0, B. Abbott, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We apply a quasi-model-independent strategy (“Sleuth”) to search for new high p_T physics in ≈100 pb^-1 of pp̅ collisions at √s = 1.8 TeV collected by the D0 experiment during 1992–1996 at the Fermilab Tevatron. We systematically analyze many exclusive final states and demonstrate sensitivity to a variety of models predicting new phenomena at the electroweak scale. No evidence of new high p_T physics is observed.

Formation Of Rydberg Atoms In An Expanding Ultracold Neutral Plasma, Scott D. Bergeson, T. C. Killian, M. J. Lim, S. Kulin, R. Dumke, S. L. Rolston

Faculty Publications

We study the formation of Rydberg atoms in expanding plasmas at temperatures of 1–1000 K and densities from 10^5–10^10 cm^-3. Up to 20% of the initially free charges recombine in about 100 us, and the binding energy of the Rydberg atoms approximately equals the increase in the kinetic energy of the remaining free electrons. Three-body recombination is expected to dominate in this regime, yet most of our results are inconsistent with this mechanism.

What Determines The Emission Peak Energy Of The Blue Luminescence In Highly Mg-Doped P-Gan?, John S. Colton, P. Y. Yu

Faculty Publications

We report a study of the 2.8 eV blue luminescence (BL) in heaviliy Mg-doped p-GaN via resonant excitation with a tunable blue dye laser. The dependence of the BL on the excitation photon energy (Eex) is unlike that of the yellow luminescence found in n-type GaN. An Urbach-type band tail, with Urbach parameter of 33 meV is observed in the vicinity of the BL energy. We propose that the peak energy of the BL marks the transition from localized states to delocalized states within this band tail.

Helium Emission From Classical T Tauri Stars: Dual Origin In Magnetospheric Infall And Hot Wind, Georgina Beristain, Suzan Edwards, John Kwan

Astronomy: Faculty Publications

High-resolution emission-line profiles of He I and He II in 31 classical T Tauri stars are analyzed with the aim of probing the environs of the star-disk interface in accreting low-mass young stars. The diagnostic power of the helium lines lies in their high-excitation potentials, which restrict their formation to a region either of high temperature or close proximity to a source of ionizing radiation. The He I profiles are decomposed into kinematic components that support the paradigm of magnetically controlled accretion from the disk onto the stellar surface but also require a significant contribution from a hot wind. A …

Iowa Academy Of Science President's Banquet, 113th Session, Iowa Academy Of Science

Iowa Academy of Science Documents

Banquet Program:

Awards - Distinguished Iowa Science Teaching: Dr. Paul L. Garvin
Awards - Distinguished Iowa Science Teaching: Dr. Mark Schneider
Awards - Distinguished Iowa Scientist: Dr. Richard G. Baker
Awards - Distinguished Service Award: Dr. Wayne I. Anderson
General Session II: Dr. Kamlesh Lulla, "The International Space Station: New Opportunities for Research and Education Outreach"

113th Session Iowa Academy Of Science Awards Luncheon, April 20, 2001, Iowa Academy Of Science

Iowa Academy of Science Documents

Program:

--- Introductions - Charles Martinson, President
--- Recognition of students participating in various statewide activities - Ernie Schiller, Chair, Student Programs Committee
--- Presentation of scholarship winners and 2002 AJAS representatives - Larry Schwinger, Director, Iowa Junior Academy of Science
--- Presentation of Excellence in Science Teaching Awards - Jeff Weld, Director, ESTA Program

Program Abstracts, 113th Session, Iowa Academy Of Science, April 20-21, 2001, Iowa Academy Of Science

Iowa Academy of Science Documents

Presentation abstracts from the annual meeting of the Iowa Academy of Science

Affinity For Scalar Fields To Dissipate, Arjun Berera, Rudnei O. Ramos

Dartmouth Scholarship

The zero-temperature effective equation of motion is derived for a scalar field interacting with other fields. For a broad range of cases, involving interaction with as few as one or two fields, dissipative regimes are found for the scalar field system. The zero-temperature limit constitutes a baseline effect that will be prevalent in any general statistical state. Thus, the results found here provide strong evidence that dissipation is the norm not the exception for an interacting scalar field system. For application to inflationary cosmology, this provides convincing evidence that warm inflation could be a natural dynamics once proper treatment of …

Conversion Of Virulent Cryphonectria Parasitica From The Lula Lake Land Trust To Hypovirulent Strains, Pearl Hwang

Honors Theses

For almost a century, the fungus, Cryphonectria parasitica has existed in the United States as a wound parasite to American chestnut (Castanea dentata) trees. However, hypovirulence, evidence of spontaneous healing in Italy and Michigan, has given the American chestnut trees hope to one day be restored into its natural range. Viruses were the cause of such spontaneous healings. My hypothesis was that a viruscontaining hypovirulent strain of C. parasitica (in a brown background) would share alleles that control anastomoses with the local virulent strains, so a virus that causes hypovirulence could be transmitted into local virulent strains in vitro. Fifty …

Building A Sustainable Future For Portland, City Club Of Portland (Portland, Or.)

City Club of Portland

No abstract provided.

Dependence Of 13C Nmr Chemical Shifts On Conformations Of Rna Nucleosides And Nucleotides, Mohsen Ebrahimi, Paolo Rossi, Christopher Rogers, Gerard S. Harbison

Gerard Harbison Publications

Cross-polarization magic-angle spinning solid-state NMR spectroscopy has been used to investigate the dependence of ¹³C sugar chemical shifts on specific conformational parameters of a variety of ribonucleotides and ribonucleosides. Solid-state NMR is a valuable tool for nucleoside and nucleotide structural studies since it provides the means to acquire spectra that correspond to single conformations, as opposed to ¹³C solutionNMRmethods. The distinct effects of sugar puckering on the C1′, C4′, and C5′ resonances of C2′ endo (S type) and C3′ endo (N type) furanoid conformations allow us to separate them into two groups. Further analysis of each group reveals …

Large-Scale Synchrony In Weakly Interacting Automata, Eric J. Friedman, Adam S. Landsberg

WM Keck Science Faculty Papers

We study the behavior of two spatially distributed (sandpile) models which are weakly linked with one another. Using a Monte Carlo implementation of the renormalization-group and algebraic methods, we describe how large-scale correlations emerge between the two systems, leading to synchronized behavior.

Ecotones: The Heartbeat Of Huxley, 2001, April 16, Kate Koch, Huxley College Of The Environment, Western Washington University

Historical Collection of Huxley Newsletters

No abstract provided.