Physical Sciences and Mathematics Commons^™

On The Power Function Of Bayesian Tests With Application To Design Of Clinical Trials: The Fixed-Sample Case, Lyle Broemeling, Dongfeng Wu

Journal of Modern Applied Statistical Methods

Using a Bayesian approach to clinical trial design is becoming more common. For example, at the MD Anderson Cancer Center, Bayesian techniques are routinely employed in the design and analysis of Phase I and II trials. It is important that the operating characteristics of these procedures be determined as part of the process when establishing a stopping rule for a clinical trial. This study determines the power function for some common fixed-sample procedures in hypothesis testing, namely the one and two-sample tests involving the binomial and normal distributions. Also considered is a Bayesian test for multi-response (response and toxicity) in …

Right-Tailed Testing Of Variance For Non-Normal Distributions, Michael C. Long, Ping Sa

Journal of Modern Applied Statistical Methods

A new test of variance for non-normal distribution with fewer restrictions than the current tests is proposed. Simulation study shows that the new test controls the Type I error rate well, and has power performance comparable to the competitors. In addition, it can be used without restrictions.

Manifestation Of Differences In Item-Level Characteristics In Scale-Level Measurement Invariance Tests Of Multi-Group Confirmatory Factor Analyses, Bruno D. Zumbo, Kim H. Koh

Journal of Modern Applied Statistical Methods

If a researcher applies the conventional tests of scale-level measurement invariance through multi-group confirmatory factor analysis of a PC matrix and MLE to test hypotheses of strong and full measurement invariance when the researcher has a rating scale response format wherein the item characteristics are different for the two groups of respondents, do these scale-level analyses reflect (or ignore) differences in item threshold characteristics? Results of the current study demonstrate the inadequacy of judging the suitability of a measurement instrument across groups by only investigating the factor structure of the measure for the different groups with a PC matrix and …

Some Guidelines For Using Nonparametric Methods For Modeling Data From Response Surface Designs, Christine M. Anderson-Cook, Kathryn Prewitt

Journal of Modern Applied Statistical Methods

Traditional response surface methodology focuses on modeling responses using parametric models with designs chosen to balance cost with adequate estimation of parameters and prediction in the design space. Using nonparametric smoothing to approximate the response surface offers both opportunities as well as problems. This article explores some conditions under which these methods can be appropriately used to increase the flexibility of surfaces modeled. The Box and Draper (1987) printing ink study is considered to illustrate the methods.

Multiple Imputation For Missing Ordinal Data, Ling Chen, Marian Toma-Drane, Robert F. Valois, J. Wanzer Drane

Journal of Modern Applied Statistical Methods

Simulations were used to compare complete case analysis of ordinal data with including multivariate normal imputations. MVN methods of imputation were not as good as using only complete cases. Bias and standard errors were measured against coefficients estimated from logistic regression and a standard data set.

Letter To The Editor, Jmasm Editors

Journal of Modern Applied Statistical Methods

No abstract provided.

Evidence For A Weak Galactic Center Magnetic Field From Diffuse Low Frequency Nonthermal Radio Emission, Ted N. Larosa, C. L. Brogan, S. N. Shore, T. J. Lazio, N. E. Kassim, M. E. Nord

Faculty Articles

New low-frequency 74 and 330 MHz observations of the Galactic center (GC) region reveal the presence of a large-scale (6° × 2°) diffuse source of nonthermal synchrotron emission. A minimum-energy analysis of this emission yields a total energy of ~(4/7f3/7) × 1052 ergs and a magnetic field strength of ~6(/f)2/7 μG (where is the proton to electron energy ratio and f is the filling factor of the synchrotron emitting gas). The equipartition particle energy density is 1.2(/f)2/7 eV cm-3, a value consistent with cosmic-ray data. However, the derived magnetic field is several orders of …

Architectures For Rule Processing Intrusion Detection And Prevention Systems, Michael E. Attig

All Computer Science and Engineering Research

High-performance intrusion detection and prevention systems are needed by network administrators in order to protect Internet systems from attack. Researchers have been working to implement components of intrusion detection and prevention systems for the highly popular Snort system in reconfigurable hardware. While considerable progress has been made in the areas of string matching and header processing, complete systems have not yet been demonstrated that effectively combine all of the functionality necessary to perform intrusion detection and prevention for real network systems. In this thesis, three architectures to perform rule processing, the heart of intrusion detection and prevention, are presented. The …

Refuge Update – May/June 2005, Volume 2, Number 3

RefugeUpdate (USFWS-NWRS)

Table of Contents:
Friends Flourish, page 3
Yukon Delta Refuge Hosts Major Shorebird Research, pages 4-5
Focus on…Nature Photography, pages 8-14
Learning a New Language, pages 18-19

Retesting A Model Of The Deming Management Method, Jesse Barfield, Caroline Fisher, Jing Li, Rajiv Mehta

Business and Information Technology Faculty Research & Creative Works

Anderson et al. (1994) developed a model of the theory of quality management underlying the Deming management method; Anderson et al. (1995) tested that model using path analysis. They used data from an existing database collected from 41 manufacturing plants in the electronics, machinery, and transportation industries with 100 or more employees. In this study, which retests their model, data were gathered from over 100 manufacturing and service companies of all sizes across the US and Canada. The measures used in the original study were modified to apply to both service and manufacturing organizations. The data were analysed using similar …

Temperature Dependence Of Homogeneous Nucleation Rates For Water: Near Equivalence Of The Empirical Fit Of Wölk And Strey, And The Scaled Nucleation Model, Barbara N. Hale

Physics Faculty Research & Creative Works

It is pointed out that the temperature fitting function of Wölk and Strey [J. Phys. Chem. 105, 11683 (2001)], recently shown to convert the Becker-Döring [Ann. Phys. (Leipzig) 24, 719 (1935)] nucleation rate into an expression in agreement with much of the experimental water nucleation rate data, also converts the Becker-Döring rate into a form nearly equivalent with the scaled nucleation rate model, J_scaled=J_oc exp[-16πΩ³(T_c/T-1)³/3(ln S)²]. In the latter expression J_oc is the inverse thermal wavelength cubed/sec, evaluated at T_c.

Mercury And C2B10 Icosahedra Interaction, Carolina C. Ilie, Petru Lunca-Popa, Jiandi Zhang, Bernard Doudin, Peter A. Dowben

Peter Dowben Publications

We contrast the interaction of mercury with adsorbed orthocarborane films and semiconducting (dehydrogenated) boron carbide. Photoemission spectra reveal small shifts in orthocarborane (C₂B₁₀H₁₂) molecular orbital binding energies as well as the shift in mercury 5d_5/2 shallow core level binding energies, suggesting only small interaction between mercury and the molecular film. Mercury does, however, interact with decomposed orthocarboranes i.e. semiconducting boron carbide.

Approaches To Uniform-Morphology: Polymer-Based Sers Substrates, Kathleen Sue Giesfeldt

Doctoral Dissertations

Polymer-nano-metallic-particle composites have demonstrated technological potential due to their unique optical and electrical properties. We report on composites prepared via physical vapor deposition of silver and gold onto pliable polydimethlysiloxane (PDMS) polymer. Rapid metal diffusion and nano-metallic-particle formation in a phase-separated surface layer of the PDMS creates unique sub-surface-based composites that vary in properties based on rate of deposition and average metal thickness. In addition, nano-metallicparticle spacing can be altered with fair reproducibility and reversibility by physically manipulating the composite. A practical technological characteristic of these composite materials arises from their potential to be molded into functional devices. Surface enhanced …

Testing The Goodness Of Fit Of Multivariate Multiplicative-Intercept Risk Models Based On Case-Control Data, Biao Zhang

Journal of Modern Applied Statistical Methods

The validity of the multivariate multiplicative-intercept risk model with I +1 categories based on casecontrol data is tested. After reparametrization, the assumed risk model is equivalent to an (I +1) -sample semiparametric model in which the I ratios of two unspecified density functions have known parametric forms. By identifying this (I +1) -sample semiparametric model, which is of intrinsic interest in general (I +1) -sample problems, with an (I +1) -sample semiparametric selection bias model, we propose a weighted Kolmogorov-Smirnov-type statistic to test the validity of the multivariate multiplicativeintercept risk model. Established are some asymptotic results …

Coverage Properties Of Optimized Confidence Intervals For Proportions, John P. Wendell, Sharon P. Cox

Journal of Modern Applied Statistical Methods

Wardell (1997) provided a method for constructing confidence intervals on a proportion that modifies the Clopper-Pearson (1934) interval by allowing for the upper and lower binomial tail probabilities to be set in a way that minimizes the interval width. This article investigates the coverage properties of these optimized intervals. It is found that the optimized intervals fail to provide coverage at or above the nominal rate over some portions of the binomial parameter space but may be useful as an approximate method.

Bias Affiliated With Two Variants Of Cohen’S D When Determining U1 As A Measure Of The Percent Of Non-Overlap, David A. Walker

Journal of Modern Applied Statistical Methods

Variants of Cohen’s d, in this instance dt and d_{adj, has the largest influence on U1 measures used with smaller sample sizes, specifically when n1 and n2 = 10. This study indicated that bias for variants of d, which influence U1 measures, tends to subside and become more manageable, in terms of precision of estimation, around 1% to 2% when n1 and n2 = 20. Thus, depending on the direction of the influence, both dt and dadj are likely to manage bias in the U1 measure quite well for smaller to …}

Tosa: A Near-Optimal Scheduling Algorithm For Multi-Channel Data Broadcast, Baihua Zheng, Xia Xu, Xing Jin, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Wireless broadcast is very suitable for delivering information to a large user population. In this paper, we concentrate on data allocation methods for multiple broadcast channels. To the best of our knowledge, this is the first allocation model that takes into the consideration of items' access frequencies, items' lengths. and bandwidth of different channels. We first derive the optimal average expected delay for multiple channels for the general case where data access frequencies, data sizes, and channel bandwidths can all be non-uniform. Second, we develop TOSA, a multi-channel allocation method that does not assume a uniform broadcast schedule for data …

Secure Human Communications Based On Biometrics Signals, Yongdong Wu, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

User authentication is the first and probably the most challenging step in achieving secure person-to-person communications. Most of the existing authentication schemes require communicating parties either share a secret/password or know each other's public key. In this paper we suggest a novel user authentication scheme that is easy to use and overcomes the requirements of sharing password or public keys. Our scheme allows two human users to perform mutual authentication and have secure communications over an open channel by exchanging biometrics signals (e. g., voice or video signals). In addition to user authentication, our scheme establishes a secret session key …

Identifying Temporal Trends In Treated Sagebrush Communities Using Remotely Sensed Imagery, Eric D. Sant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The sagebrush shrub steppe ecosystem is of great concern to researchers, conservationists, and the general public because of the documented declines associated with it. Monitoring in the past has generally been point-based and lacking in long-term data. To overcome these deficiencies, an automated method of monitoring was developed using GIS and remote sensing.

Geospatial layers of vegetation, soils, fire history, roads, streams, and springs were acquired and processed to characterize selected monitoring locations. A temporal set of Landsat satellite imagery for the past 30 years was normalized to reduce the effects of sun angle, haze, and sensor change. After normalization, …

Humic And Fulvic Acids: Effects On Plant Nutrition And Growth, Jason Tew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humic substances are reported to improve plant growth and nutrient uptake, with iron the most studied nutrient. The most common forms of iron in soils are iron oxides, which are stable under aerobic conditions and unavailable for plant uptake. Iron deficient plants become chlorotic, which reduces growth and yield. To determine if humic substances can reduce iron chlorosis, five commercially available organic acids were tested on maize grown in sand columns at high pH. The dry granular humic acid from Aldrich Chemical Company applied at 84.4 g/liter of sand by volume (5% by mass) and 1 g/liter added with irrigation …

Relating Bedrock Strength To Hydraulic Driving Forces Along The Large-Scale Profile Of The Colorado River In Glen And Grand Canyons, Rob D. Mackley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The role of bedrock on the longitudinal profile of the Colorado River has intrigued workers for over a century. The river's profile exhibits large-scale (10 to 100 km) variations in geomorphology that are qualitatively associated with changes in rock type. This study provides the first bedrock-strength data to quantitatively test the relation of bedrock-resisting to hydraulic-driving forces in Glen and Grand canyons. The intent of this study is to explore the role, if any, that bedrock has on large-scale geomorphic variations along the profile of the Colorado River. Rock-strength data collected at 84 sites along the river corridor in Glen …

The Quaternary Tectonic And Structural Evolution Of The San Felipe Hills, California, Stefan M. Kirby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We examine the transition between extension and strike-s lip in the San Felipe Hills, western Salton Trough, southern California using new and compiled geologic mapping, measured stratigraphic sections, magnetostratigraphy, and structural analysis. A 625 m measured section describes the Borrego, Ocotillo , and Brawley formations in the SE San Felipe Hills and constrains a regional disconformity and correlative angular unconformity at ~ 1 Ma. Sedimentation rates for the Brawley Formation above the disconformity range from 1.0 to 1.2 mm/yr, palcoflow was to the ENE. The Brawley Formation consists of three interbeddcd lithofac ics; (I) fluvial and fluvio-d eltaic, (2) lacustrinc, …

Characteristics Of Ungulate Behavior And Mortality Associated With Wire Fences, Justin L. Harrington

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied the characteristics of fence mortality in pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus), and elk (Cervus elaphus) along roads in Colorado and Utah from June 2004 to June 2005. I defined a direct-fence mortality as a carcass caught directly in a fence and an indirect-fence mortality as a carcass on the ground within 10 m of a fence. I estimated an average annual direct mortality occurrence of 0.25 mortalities/km (0.078 mule deer mortalities/km, 0.113 pronghorn mortalities/km, and 0.061 elk mortalities/km). The highest fence-mortality rates for ungulates occurred during August, which coincided with …

Examination Of Exhumed Faults In The Western San Bernardino Mountains, California: Implications For Fault Growth And Earthquake Rupture, Joseph R. Jacobs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The late Miocene Cedar Springs fault system is a high-angle transpressional system in the Silverwood Lake area, western San Bernardino Mountains, southern California. This thesis presents the study of oblique-slip faults with modest amounts of slip, which represent the early stages of fault development by using slip as a proxy for maturity. A structural and geochemical characterization is provided for six fault zones ranging from 39 m of slip to 3.5 km of offset in order to develop a model of fault zone geometry and composition. Basic geometric and kinematic results are provided for an additional 29 small-displacement (cm- to …

Stratigraphic And Structural Analysis Of Coals In The Ferron Sandstone Member Of The Mancos Shale And Fruitland Formation: Relationship To Coal Reservoir Permeability And Coalbed Methane Production, Jason Lynn Kneedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coal reservoir quality in the Ferron Sandstone Member of the Mancos Shale, and in the Fruitland Formation is dependent on coal cleat characteristics. Coal reservoir permeability increases as a result of high cleat density. From careful outcrop examination, we were able to identify several factors that increase cleat density. Vitrain coal typically has the highest fracture density as a result of having well-developed face cleats and conchoidal fractures. Clarain coal contains face and butt cleats. Cleat density in clarain is also controlled by mechanical layer thickness. As mechanical layer thickness decreases, cleat density increases. Durain and fusain coals typically contain …

Measurements Of The Secondary Electron Emission Properties Of Insulators, Clint D. Thomson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Measurements of the electron-induced electron emission properties of insulators are important to many applications including spacecraft charging, scanning electron microscopy, electron sources, and particle detection technology. However, these measurements are difficult to make since insulators can charge either negatively or positively under charge particle bombardment that in turn alters insulator emissions. In addition, incident electron bombardment can modify the conductivity, internal charge distribution, surface potential, and material structure in ways that are not well understood. A primary goal of this dissertation work has been to make consistent and accurate measurements of the uncharged electron yields for insulator materials using innovative …

Simulated Browsing Impacts On Aspen Sucker's Survival And Growth, Koketso Tshireletso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Western forests dominated by aspen (Populus tremuloides Michx.) are highly regarded by most resource managers for their ability to provide a variety of benefits (Bartos and Mueggler 1982, Mueggler 1988). They noted aspen to be beneficial for production of livestock forage, wildlife habitat, and scenic beauty, and they are a potentially valuable source of wood products. However, in the West, communities are concerned about the dwindling acreage of aspen. The decline of aspen has been partly attributed to excessive ungulate browsing (Smith et al. 1972, Collins and Urness 1983, Bartos and Campbell 1998). Long-term grazing exclosures have also revealed …

X-Ray Generation From Metal Targets Coated With Wavelength-Scale Spheres, D. R. Symes, H. A. Sumeruk, I. V. Churina, Thomas D. Donnelly, J. Landry, T. Ditmire

All HMC Faculty Publications and Research

X-ray yield measurements from targets coated with wavelength-scale spheres are compared with measurements from polished targets. Evidence for a hotter resonant electron temperature due to field enhancements from Mie resonances in the spheres is investigated.

Wavelet Analysis Of Magnetometer Data, Inga Maslova

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The wavelet analysis of the ground-based magnetograms' records is performed in this project. We explore the records from low, medium and high latitude stations during a calm period and a stormy one. Different methods for detecting and estimating the tail index of heavy-tailed distributions are compared. A detailed analysis of the properties of the distributions of the discrete wavelet transform coefficients of magnetometer data is presented. Conclusions on the tail index estimation techniques and the distribution of the discrete wavelet transform coefficients are made.

Experimental Studies Of Intra- And Intermolecular Chemical Structure, Cara Lynn Nygren

Doctoral Dissertations

The purpose of this study was two fold. The determination of hydrogen atom positions by X-ray diffraction methods is widely underused. With advances in instrument and computing technology, the use of X-ray diffraction experiments to accurately image the electron density associated with a hydrogen bond has become feasible. Secondly, general crystallographic computing programs analyze diffraction data by employing a spherical atom model. However, no such atom can be defined solely by a sphere when bound in a molecule. The use of spherical harmonics to model diffraction data enables a more complete description of the electron density in a molecular system. …