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2003

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Articles 1501 - 1530 of 3876

Full-Text Articles in Physical Sciences and Mathematics

A Different Future For Social And Behavioral Science Research, Shlomo S. Sawilowsky May 2003

A Different Future For Social And Behavioral Science Research, Shlomo S. Sawilowsky

Journal of Modern Applied Statistical Methods

The dissemination of intervention and treatment outcomes as effect sizes bounded by conf idence intervals in order to think meta-analytically was promoted in a recent article in Educational Researcher. I raise concerns with unfettered reporting of effect sizes, point out the con in confidence interval, and caution against thinking meta-analytically. Instead, cataloging effect sizes is recommended for sample size estimation and power analysis to improve social and behavioral science research.


Jmasm6: An Algorithm For Generating Exact Critical Values For The Kruskal-Wallis One-Way Anova, Todd C. Headrick May 2003

Jmasm6: An Algorithm For Generating Exact Critical Values For The Kruskal-Wallis One-Way Anova, Todd C. Headrick

Journal of Modern Applied Statistical Methods

A Fortran 77 subroutine is provided for computing exact critical values for the Kruskal-Wallis test on k independent groups with equal or unequal samples sizes. The subroutine requires the user to provide sorting and ranking routines and a uniform pseudo-random number generator. The program is available from the author on request.


A Recursive Algorithm For Fractionally Differencing Long Data Series, Joseph Mccarthy, Robert Disario, Hakan Saraoglu May 2003

A Recursive Algorithm For Fractionally Differencing Long Data Series, Joseph Mccarthy, Robert Disario, Hakan Saraoglu

Journal of Modern Applied Statistical Methods

We propose a recursive algorithm to fractionally difference time series data. The algorithm eliminates the need to evaluate the gamma function directly, and hence avoids the overflow problem that arises when fractionally differencing a long data series. The proposed algorithm can be implemented using any general matrix programming language. An implementation using SAS is presented. The algorithm and the code provide a practical approach to including fractional differencing as part of a time series data analysis.


Reply To “Comment On ‘Classical Density Functional Theory Of Freezing In Simple Fluids: Numerically Induced False Solutions’ ”, M. Valera, F. J. Pinski, Duane D. Johnson May 2003

Reply To “Comment On ‘Classical Density Functional Theory Of Freezing In Simple Fluids: Numerically Induced False Solutions’ ”, M. Valera, F. J. Pinski, Duane D. Johnson

Duane D. Johnson

Recently we solved, via discrete numerical grids, the Ramakrishna-Yossouff density-functional theory equations for the freezing transition and obtained an intricate phase diagram of hard-sphere mixtures. Even though such methods provide more variational freedom than basis-set methods, we found that the thermodynamic quantities were sensitive to the spacing of numerical grids employed and observed numerically induced false minima. Dasgupta and Valls have commented that these false minima were due to our use of k-space methods and, hence, their early works based on a fully r-space approach are qualitatively correct, despite also being sensitive to the mesh granularity. Here, we clarify the …


The Global Dynamics Of Isothermal Chemical Systems With Critical Nonlinearity, Yi Li, Yuanwei Qi May 2003

The Global Dynamics Of Isothermal Chemical Systems With Critical Nonlinearity, Yi Li, Yuanwei Qi

Yi Li

In this paper, we study the Cauchy problem of a cubic autocatalytic chemical reaction system u1,t = u1,xxuα1 uβ2, u2,t = du2,xx+ uα1 uβ2 with non-negative initial data, where the exponents α,β satisfy 1<α,β<2, α+β = 3 and the constant d>0 is the Lewis number. Our purpose is to study the global dynamics of solutions under mild decay of initial data as |x|→. We show the exact large time behaviour of solutions which is universal.


Σary, Minnesota State University Moorhead, Mathematics Department May 2003

Σary, Minnesota State University Moorhead, Mathematics Department

Math Department Newsletters

No abstract provided.


Stability Of Hyperbolic And Nonhyperbolic Fixed Points Of One-Dimensional Maps, Fozi M. Dannan, Saber Elaydi, Vadim Ponomarenko May 2003

Stability Of Hyperbolic And Nonhyperbolic Fixed Points Of One-Dimensional Maps, Fozi M. Dannan, Saber Elaydi, Vadim Ponomarenko

Mathematics Faculty Research

We present a complete theory for the stability of non-hyperbolic fixed points of one-dimensional continuous maps. As well as we give simple criteria for the global stability of general maps without using derivatives.


Dielectric Constant And Proton Order And Disorder In Ice Ih: Monte Carlo Computer Simulations, Steven W. Rick May 2003

Dielectric Constant And Proton Order And Disorder In Ice Ih: Monte Carlo Computer Simulations, Steven W. Rick

Chemistry Faculty Publications

The dielectric properties of ice Ih are studied using a Monte Carlo algorithm for sampling over proton configurations. The algorithm makes possible the calculation of the dielectric constant and other properties of the proton-disordered crystal. Results are presented for three classical models of water, two commonly used nonpolarizable models (SPC/E and TIP4P) and a polarizable model
(TIP4P-FQ).


Optimal Beam Splitters For The Division-Of-Amplitude Photopolarimeter, R. M.A. Azzam, A. De May 2003

Optimal Beam Splitters For The Division-Of-Amplitude Photopolarimeter, R. M.A. Azzam, A. De

Electrical Engineering Faculty Publications

Optimal optical parameters of the beam splitter that is used in the division-of-amplitude photopolarimeter are determined. These are (1) 50%–50% split ratio of the all-dielectric beam splitter, (2) differential phase shifts in reflection and transmission Δr and Δt that differ by ±π/2, and (3) ellipsometric parameters (ψr, ψt)= (27.368°, 62.632°) or (62.632°, 27.368°). It is also shown that for any nonabsorbing beam splitter that splits incident unpolarized light equally, the relationship ψrt=π/2 is always satisfied.


The Global Dynamics Of Isothermal Chemical Systems With Critical Nonlinearity, Yi Li, Yuanwei Qi May 2003

The Global Dynamics Of Isothermal Chemical Systems With Critical Nonlinearity, Yi Li, Yuanwei Qi

Mathematics and Statistics Faculty Publications

In this paper, we study the Cauchy problem of a cubic autocatalytic chemical reaction system u1,t = u1,xxuα1 uβ2, u2,t = du2,xx+ uα1 uβ2 with non-negative initial data, where the exponents α,β satisfy 1<α,βd>0 is the Lewis number. Our purpose is to study the global dynamics of solutions under mild decay of initial data as |x|→. We show the exact large time behaviour of solutions which is universal.


Finite Element Studies In Metal Cutting, Suhail Ahmed May 2003

Finite Element Studies In Metal Cutting, Suhail Ahmed

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

AdvantEdge is a finite element software package that integrates advanced dynamics, thermo-mechanically coupled finite element numerics and material modelling appropriate for machining processes. AdvantEdge allows users to specify the workpiece material, tool geometry and cutting conditions. It then provides accurate estimates of thermo-mechanical properties of machining processes such as cutting forces, chip morphology, machined surface residual stresses and temperature behavior of the tool and the workpiece. We will use AdvantEclge to investigate two areas of interest in metal cutting: process clamping via crushing of workpiece material and drilling of metal stacks.


Test Suite For Multiobjective Optimization And Results Using Normal Boundary Intersection (Nbi) In Design Explorer, Siva Kumar Natarajan May 2003

Test Suite For Multiobjective Optimization And Results Using Normal Boundary Intersection (Nbi) In Design Explorer, Siva Kumar Natarajan

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

Several methods have been developed to solve multiobjective optimization problems (MOP's). One of these, Normal Boundary Intersection (NBI), is a method developed by John Dennis and Indraneel Das. NBI is used at The Boeing Company as a tool to solve MOP's. This report presents a test suite of MOP's that I developed for Boeing during me internship in summer 2003.

The problems in the test suite were chosen to represent the different types of multiobjective optimization problems that could arise in practice and the complexities involved in solving them. These problems range from those that have nice convex Pareto surfaces …


Sequential Traitor Tracing, R. Safavi-Naini, Yejing Wang May 2003

Sequential Traitor Tracing, R. Safavi-Naini, Yejing Wang

Faculty of Informatics - Papers (Archive)

We consider a new type of traitor tracing scheme, called sequential traitor tracing, that protects against rebroadcasting of decrypted content. Sequential traceability (TA) schemes trace all up to c traitors and remove the shortcomings of dynamic tracing schemes. We give two general constructions and show the relationship between c-TA codes and sequential tracing schemes.


Running Linux On Back-End Computers In The Xinu Lab, Douglas E. Comer, Xuxian Jiang May 2003

Running Linux On Back-End Computers In The Xinu Lab, Douglas E. Comer, Xuxian Jiang

Department of Computer Science Technical Reports

No abstract provided.


Energy-Efficient Routing Schemes For Sensor Networks, Maleq Khan, Gopal Pandurangan, Bharat Bhargava May 2003

Energy-Efficient Routing Schemes For Sensor Networks, Maleq Khan, Gopal Pandurangan, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.


Economics Of A Collaborative Peer-To- Peer Infrastructure For Content Distribution, Mohamed Hefeeda, Philipp Afeche, Bharat Bhargava May 2003

Economics Of A Collaborative Peer-To- Peer Infrastructure For Content Distribution, Mohamed Hefeeda, Philipp Afeche, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.


Collectcast: A Peer-To-Peer Service For Media Streaming, Mohamed Hefedda, Ahsam Habib, Dongyan Xu, Bharat Bhargava, Boyan Botev May 2003

Collectcast: A Peer-To-Peer Service For Media Streaming, Mohamed Hefedda, Ahsam Habib, Dongyan Xu, Bharat Bhargava, Boyan Botev

Department of Computer Science Technical Reports

No abstract provided.


Idioms In Ovm, C. Flack, Antony L. Hosking, Jan Vitek May 2003

Idioms In Ovm, C. Flack, Antony L. Hosking, Jan Vitek

Department of Computer Science Technical Reports

No abstract provided.


Dipole-Bound Anions, Nathanael Isaac Hammer May 2003

Dipole-Bound Anions, Nathanael Isaac Hammer

Doctoral Dissertations

Any molecule with a dipole moment above approximately 2.5 Debye can form a stable negative ion (dipole-bound anion). These anions are best produced by “resonance” charge exchange from atoms in high Rydberg states (Rydberg electron transfer, RET). RET to form dipole-bound anions occurs over a narrow range of effective principle quantum number, n*. Dipole-bound anions for 32 molecules with dipole moments between 2.5 and 6.0 Debye have been studied. The excess electron in such an anion is very diffuse and weakly bound. Binding energies (electron affinities, EAs) are estimated from the narrow range of n* at which charge exchange occurs …


Sr3Mgpto6, Mark D. Smith, Hans Conrad Zur Loye May 2003

Sr3Mgpto6, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

Single crystals of the mixed alkaline earth platinate, tristrontium magnesium platinum hexaoxide, Sr3MgPtO6, were grown from a KOH flux at 1273 K. The compound adopts the rhombohedral K4CdCl6 structure type, featuring chains of face-shared, distorted MgO6 trigonal prisms (Mg site symmetry 32) and PtO6 octahedra (Pt site symmetry ) surrounded by columns of Sr2+ ions (Sr site symmetry 2).


Sequence Stratigraphy And Depositional Facies Of Lower Ordovician Cyclic Carbonate Rocks, Southern Missouri, U.S.A., Robert Brandon Overstreet, Francisca Oboh-Ikuenobe, Jay M. Gregg May 2003

Sequence Stratigraphy And Depositional Facies Of Lower Ordovician Cyclic Carbonate Rocks, Southern Missouri, U.S.A., Robert Brandon Overstreet, Francisca Oboh-Ikuenobe, Jay M. Gregg

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Lower Ordovician cyclic carbonate strata of southern Missouri were deposited in a warm, shallow, epeiric sea on a fully aggraded carbonate platform. Sedimentological characteristics distinguish the Jefferson City and Cotter dolomites from the underlying Gasconade and Roubidoux formations. Mixed carbonate-siliciclastic sedimentation characterizes the Roubidoux Formation, with sandstones accounting for up to 60% of sedimentation. The Gasconade, Jefferson City, and Cotter dolomites exhibit an increased occurrence of chalcedonic chert nodules in very similar shape and texture to the gypsum and anhydrite nodules common on modern sabkha supratidal flats. Casts of halite and ghosts of gypsum laths also exist in the Jefferson …


Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls May 2003

Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls

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

The ability to ensure uniformity of temperature within a given finite physical region is an essential element in the success of many scientific processes, especially those that involve extreme fluctuation in temperature. Such a process is performed in an instrument called the LightTyper developed by Idaho Technology, Inc. of Salt Lake City Utah. This paper details the development and results of a scheme intended to obtain a heating design that ensures a high degree of temperature uniformity within the Idaho Technology instrument. Due to the experiments performed during this project, we were able to answer many questions that concerned finding …


Modeling Correlated Time-Varying Covariate Effects In A Cox-Type Regression Model, Mourad Tighiouart May 2003

Modeling Correlated Time-Varying Covariate Effects In A Cox-Type Regression Model, Mourad Tighiouart

Journal of Modern Applied Statistical Methods

In this paper, I extend the proposed model by McKeague and Tighiouart (2000) to handle time-varying correlated covariate effects for the analysis of survival data. I use the conditional predictive ordinates (CPO’s) for model comparison and the methodology is illustrated by an application to nasopharynx cancer survival data. A reversible jump MCMC sampler to estimate the CPO’s will be presented.


Incorporating Sampling Weights Into The Generalizability Theory For Large-Scale Analyses, Christopher W. T. Chiu, Ronald S. Fesco May 2003

Incorporating Sampling Weights Into The Generalizability Theory For Large-Scale Analyses, Christopher W. T. Chiu, Ronald S. Fesco

Journal of Modern Applied Statistical Methods

Large scale studies frequently use complex sampling procedures, disproportionate sampling weights, and adjustment techniques to account for potential bias due to nonresponses and to ensure that results from the sample can be generalized to a larger population. Survey researchers are concerned about measurement error and the use of weights in developing models. Consequently, multiple weighting factors are used and these weighting factors are manifested as a final survey (composite) weight available for analysis. We developed a method to incorporate an external weighting factor like this for analyses of measurement errors in the theory of generalizability to provide researchers with a …


A More Efficient Way Of Obtaining A Unique Median Estimate For Circular Data, B. Sango Otieno, Christine M. Anderson-Cook May 2003

A More Efficient Way Of Obtaining A Unique Median Estimate For Circular Data, B. Sango Otieno, Christine M. Anderson-Cook

Journal of Modern Applied Statistical Methods

The procedure for computing the sample circular median occasionally leads to a non-unique estimate of the population circular median, since there can sometimes be two or more diameters that divide data equally and have the same circular mean deviation. A modification in the computation of the sample median is suggested, which not only eliminates this non-uniqueness problem, but is computationally easier and faster to work with than the existing alternative.


A Semiparametric Regression Model For Oligonucleotide Arrays, Jianhua Hu, Guosheng Yin May 2003

A Semiparametric Regression Model For Oligonucleotide Arrays, Jianhua Hu, Guosheng Yin

Journal of Modern Applied Statistical Methods

A semiparametric model incorporating the spline smoothing technique is proposed to study oligonucleotide gene expression data. No specific parametric functional form is assumed for mismatch probe intensities, which allows much more flexibility in the fitted model. The new approach improves the model fitting, hence the estimation of expression indexes. The method is applied to a data set of 18 HuGeneFL arrays.


The Way Ahead In Qualitative Computing, Tom Richards, Lyn Richards May 2003

The Way Ahead In Qualitative Computing, Tom Richards, Lyn Richards

Journal of Modern Applied Statistical Methods

Specialized computer programs for Qualitative Research in social sciences have greatly changed ways of doing QR, the reliability and comprehensiveness of results, the ability to inspect and challenge a researcher’s working, and the relationship with quantitative methods in social research. This article explores these claims in the context of N6 (NUD*IST) and NVivo, the two programs designed by the authors; and considers possible future developments in the field.


Substrate Dependent Bonding Of Chemisorbed 1,1’-Biphenyl-4,4’-Dimethanethiol, A. N. Caruso, R. Rajesekaran, Jody G. Redepenning, Yaroslav B. Losovyj, Peter A. Dowben May 2003

Substrate Dependent Bonding Of Chemisorbed 1,1’-Biphenyl-4,4’-Dimethanethiol, A. N. Caruso, R. Rajesekaran, Jody G. Redepenning, Yaroslav B. Losovyj, Peter A. Dowben

Peter Dowben Publications

We compare the adsorption of 1,1’-biphenyl-4,4’-dimethanethiol (BPDMT) on gold and cobalt surfaces. The molecular orbitals, identified from combined photoemission and inverse photoemission studies, exhibit shifts in binding energies with different deposition methods and substrates. These shifts indicate that this potential molecular dielectric exhibits stronger bonding to cobalt surfaces than gold surfaces.


Predicting Mountain Pine Beetle Development With The Extended Von Foerster Model, Jeffrey Tullis Leek May 2003

Predicting Mountain Pine Beetle Development With The Extended Von Foerster Model, Jeffrey Tullis Leek

Undergraduate Honors Capstone Projects

The mountain pine beetle (Dendroctonus ponderosae Hopkins) represents a significant threat to ponderosa pine and lodgepole pine stands in the western United States, and has the potential to threaten commercially valuable jack pine in both the United States and Canada. The success of the mountain pine beetle is based on synchronization of developmental events to time cold-hardened life stages for extreme winter temperatures and to facilitate mass attack and overwhelm the defenses of the host. This paper presents a solution methodology for an extended McKendrick - von Foerster model for the development of the mountain pine beetle in varying …


Field Testing Of Abrasion Resistant Carbides, Kevin C. Orme May 2003

Field Testing Of Abrasion Resistant Carbides, Kevin C. Orme

Undergraduate Honors Capstone Projects

Chromium, tungsten, titanium, and vanadium carbides were investigated to determine relative cost of operation for each in an agricultural environment. For use on a ripper plow, these carbides were field tested in two different soil types; one soil having a matrix of gravel and cobblestones, and the other consisting of hard dirt and large underground rocks. Each alloy was applied to a high carbon plow point using an arc welding process. Along with the welded points, cast chromium carbide was tested. The results are given in price per acre and not solely longevity of the point. It was concluded that …