Digital Commons Network^™

November 2004, Syracuse Department Of Economics

Economics - All Scholarship

No abstract provided.

Stressing Concepts And Teaching In The Classroom: A Low-Technology Approach Using Concept Tests And Classroom Polls, Walter S. Borowski

EKU Faculty and Staff Scholarship

Electronic student response technologies can be used effectively to increase learning in the classroom. Although these systems are not terribly expensive, their purchase may be out of reach for many departments and institutions. Here we model a low-technology approach that stresses active learning, peer teaching, and testing student understanding of key concepts by using think-pair-share sessions and in-class responses to key concept-test questions.

Questions used in class are chosen carefully to emphasize a concept essential to understanding some aspect of geoscience in an introductory geology course. Each class involves the introduction of a key concept question or questions followed by: …

A Maximal Chain Approach For Scheduling Tasks In A Multiprocessor Systems, Sachin Pawaskar, Hesham Ali

Computer Science Faculty Proceedings & Presentations

Scheduling dependent tasks is one of the most challenging versions of the scheduling problem in parallel and distributed systems. It is known to be computationally intractable in its general form as well as several restricted cases. As a result, researchers have studied restricted forms of the problem by constraining either the task graph representing the parallel tasks or the computer model. Also, in an attempt to solve the problem in the general case, a number of heuristics have been developed. In this paper, we study the scheduling problem for a fixed number of processors m. In the proposed work, we …

Assessing Treatment Effects In Randomized Longitudinal Two-Group Designs With Missing Observations, James Algina, H. J. Keselman

Journal of Modern Applied Statistical Methods

SAS’s PROC MIXED can be problematic when analyzing data from randomized longitudinal two-group designs when observations are missing over time. Overall (1996, 1999) and colleagues found a number of procedures that are effective in controlling the number of false positives (Type I errors) and are yet sensitive (powerful) to detect treatment effects. Two favorable methods incorporate time in study and baseline scores to model the missing data mechanism; one method was a single-stage PROC MIXED ANCOVA solution and the other was a two-stage endpoint analysis using the change scores as dependent scores. Because the twostage approach can lack sensitivity to …

Type I Error Rates For A One Factor Within-Subjects Design With Missing Values, Miguel A. Padilla, James Algina

Journal of Modern Applied Statistical Methods

Missing data are a common problem in educational research. A promising technique, that can be implemented in SAS PROC MIXED and is therefore widely available, is to use maximum likelihood to estimate model parameters and base hypothesis tests on these estimates. However, it is not clear which test statistic in PROC MIXED performs better with missing data. The performance of the Hotelling- Lawley-McKeon and Kenward-Roger omnibus test statistics on the means for a single factor withinsubject ANOVA are compared. The results indicate that the Kenward-Roger statistic performed better in terms of keeping the Type I error close to the nominal …

Size And Power Of The Reset Test As Applied To Systems Of Equations: A Bootstrap Approach, Ghazi Shukur, Panagiotis Mantalos

Journal of Modern Applied Statistical Methods

The size and power of various generalization of the RESET test for functional misspecification are investigated, using the “Bootsrap critical values”, in systems ranging from one to ten equations. The properties of 8 versions of the test are studied using Monte Carlo methods. The results are then compared with another study of Shukur and Edgerton (2002), in which they used the asymptotic critical values instead and found that in general only one version of the tests works well regarding size properties. In our study, when applying the bootstrap critical values, we find that all the tests exhibits correct size even …

Front Matter, Jmasm Editors

Journal of Modern Applied Statistical Methods

No abstract provided.

Variance Stabilizing Power Transformation For Time Series, Victor M. Guerrero, Rafael Perera

Journal of Modern Applied Statistical Methods

A confidence interval was derived for the index of a power transformation that stabilizes the variance of a time-series. The process starts from a model-independent procedure that minimizes a coefficient of variation to yield a point estimate of the transformation index. The confidence coefficient of the interval is calibrated through a simulation.

Multivariate Contrasts For Repeated Measures Designs Under Assumption Violations, Lisa M. Lix, Aynslie M. Hinds

Journal of Modern Applied Statistical Methods

Conventional and approximate degrees of freedom procedures for testing multivariate interaction contrasts in groups by trials repeated measures designs were compared under assumption violation conditions. Procedures were based on either least-squares or robust estimators. Power generally favored test procedures based on robust estimators for non-normal distributions, but was influenced by the degree of departure from non-normality, definition of power, and magnitude of the multivariate effect size.

Interval Estimation For The Scale Parameter Of Burr Type X Distribution Based On Grouped Data, Amjad D. Al-Nasser, Ayman Baklizi

Journal of Modern Applied Statistical Methods

The application of some bootstrap type intervals for the scale parameter of the Burr type X distribution with grouped data is proposed. The general asymptotic confidence interval procedure (Chen & Mi, 2001) is studied. The performance of these intervals is investigated and compared. Some of the bootstrap intervals give better performance for situations of small sample size and heavy censoring.

An Algorithm And Code For Computing Exact Critical Values For The Kruskal-Wallis Nonparametric One-Way Anova, Sikha Bagui, Subhash Bagui

Journal of Modern Applied Statistical Methods

In this article, an algorithm and code to compute exact critical values (or percentiles) for Kruskal-Wallis test on k independent treatment populations with equal or unequal sample sizes using Visual Basic (VB.NET) is provided. This program has the ability to calculate critical values for any k , sample sizes (n_i ) , and significance level (α ) . An exact critical value table for k = 4 is also developed. The table will be useful to practitioners since it is not available in standard nonparametric statistics texts. The program can also be used to compute any other …

Pseudo-Random Number Generation In R For Commonly Used Multivariate Distributions, Hakan Demirtas

Journal of Modern Applied Statistical Methods

An increasing number of practitioners and applied statisticians have started using the R programming system in recent years for their computing and data analysis needs. As far as pseudo-random number generation is concerned, the built-in generator in R does not contain multivariate distributions. In this article, R routines for widely used multivariate distributions are presented.

Special Section: Commemorating The Retirement Of R. Clifford Blair, Jmasm Editors

Journal of Modern Applied Statistical Methods

This Special Section, "Commemorating the Retirement of R. Clifford Blair," contains five articles united by this section theme (also included individually above).

Confidence Intervals On Subsets May Be Misleading, Juliet Popper Shaffer

Journal of Modern Applied Statistical Methods

A combination of hypothesis testing and confidence interval construction is often used in social and behavioral science studies. Sometimes confidence intervals are computed or reported only if a null hypothesis is rejected, perhaps to see whether the range of values is of practical importance. Sometimes they are constructed or reported only if a null hypothesis is accepted, in order to assess the range of plausible nonnull values due to inadequate power to detect them. Even if always computed, they are interpreted differently, depending on whether the null value is or is not included. Furthermore, many studies in which the null …

Mentoring Doctoral Students: A Personal Perspective, Bruce W. Hall

Journal of Modern Applied Statistical Methods

In this brief essay, I reflect on the mentoring process based on advising over thirty doctoral students in measurement, evaluation, and research. There is considerable cause for optimism, and it is among the professors’ highest honor to mentor the doctoral student.

On A Simple Method For Analyzing Multivariate Survival Data Using Sample Survey Methods, Pingfu Fu, J. Sunil Rao

Journal of Modern Applied Statistical Methods

A simple technique is illustrated for analyzing multivariate survival data. The data situation arises when an individual records multiple survival events, or when individuals recording single survival events are grouped into clusters. Past work has focused on developing new methods to handle such data. Here, we use a connection between Poisson regression and survival modeling and a cluster sampling approach to adjust the variance estimates. The approach requires parametric assumption for the marginal hazard function, but avoids specification of a joint multivariate survival distribution. A simulation study demonstrates the proposed approach is a competing method of recent developed marginal approaches …

Monte Carlo Evaluation Of Ordinal D With Improved Confidence Interval, Du Feng, Norman Cliff

Journal of Modern Applied Statistical Methods

This article reports a Monte Carlo evaluation of ordinal statistic d with modified confidence intervals (CI) for location comparison of two independent groups under various conditions. Type I error rate, power, and coverage of CI of d were compared to those of the Welch's t-test.

Confidence Elicitation And Anchoring In The Respondent-Generated Intervals (Rgi) Protocol, Liping Chu, S. James Press, Judith M. Tanur

Journal of Modern Applied Statistical Methods

The Respondent-Generated Intervals protocol (RGI) has been used to have respondents recall the answer to a factual question by giving not only a point estimate but also bounds within which they feel it is almost certain that the true value of the quantity being reported upon falls. The RGI protocol is elaborated in this article with the goal of improving the accuracy of the estimators by introducing cueing mechanisms to direct confident (and thus presumably accurate) respondents to give shorter intervals and less confident (and thus presumably less accurate) respondents to give longer ones.

A Note On Extending Scheffé’S Modified Multiple-Comparison Procedure To Other Analysis Situations, Xinyue Zhou, Joel R. Levin

Journal of Modern Applied Statistical Methods

This article extends Scheffé’s modified (sequential) multiple-comparison procedure in one-way analysisof- variance to other analysis situations, including interaction comparisons in factorial ANOVA designs, tests of partial regression coefficients in multiple-regression analysis, and comparisons of means in onefactor multivariate analyses of variance. Researchers who are concerned with maintaining familywise Type I error rates while increasing statistical power relative to the original (simultaneous) Scheffé-based procedures are encouraged to consider these improved multiple-comparison methods.

A Modification Of The Em Algorithm To Estimate An Andersen-Gill Gamma Frailty Model For Multivariate Failure Time Data, Maria Antònia Barceló, Marc Saez

Journal of Modern Applied Statistical Methods

A modification of the Andersen-Gill gamma shared frailty model is presented. The variance of the frailty is directly modeled by means of a generalized linear model, the EM algorithm is modified in order to simultaneously estimate a semiparametric model for the failure times and a model for the variance of the frailty. A simulation study is conducted to evaluate the performance of the proposed algorithm (EMB algorithm) and compared with other methods, a marginal model, and a conditional model. Multivariate data from a nosocomial infection study is used to illustrate the methods. The EMB fit turned out to be better …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 3, November 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Ists E-Newsletter, November 2004, Iowa Academy Of Science

ISTS Newsletter

In this issue:

--Notes from Your President

--ISTS Fall '04 Conference Comments

--Announcements—a slew of opportunities

--Your ISTS Leadership Team

Theoretical Study Of The Magnetic Ordering In Rare-Earth Compounds With Face-Centered-Cubic Structure, Chun-Gang Duan, Renat F. Sabirianov, Jianjun Liu, Wai-Ning Mei, Peter A. Dowben, John R. Hardy

Physics Faculty Publications

We present a detailed theoretical study of the magnetic ordering in heavy rare-earth compounds with a face-centered-cubic structure. In addition to the exchange interactions which are counted up to the third nearest neighbors, the effect of the dipolar interactions and magnetic anisotropic effect are also included in our model Hamiltonian. The interactions parameters are obtained from first-principles band-structure calculations by fitting the total energies of different magnetic configurations to the Heisenberg Model. Thus from utilizing the Monte Carlo simulations, we explained the formation of different magnetic structures in the rare-earth compounds.

Checking If There Exists A Monotonic Function That Is Consistent With The Measurements: An Efficient Algorithm, Kavitha Tupelly, Vladik Kreinovich, Karen Villaverde

Departmental Technical Reports (CS)

In many problems in science and engineering ranging from astrophysics to geosciences to financial analysis, we know that a physical quantity y depends on the physical quantity x, i.e., y=f(x) for some function f(x), and we want to check whether this dependence is monotonic. Specifically, finitely many measurements of xi and yi=f(xi) have been made, and we want to check whether the results of these measurements are consistent with the monotonicity of f. An efficient parallelizable algorithm is known for solving this problem when the values xi are known precisely, while the values yi are known with interval uncertainty. In …

Probabilistic Approach To Trust: Ideas, Algorithms, And Simulations, Pattama Jaksurat, Eric A. Freudenthal, Martine Ceberio, Vladik Kreinovich

Departmental Technical Reports (CS)

In traditional security systems, for each task, we either trust an agent or we don't. If we trust an agent, we allow this agent full access to this particular task. This agent can usually allow his trusted sub-agents the same access, etc. If a trust management system only uses "trust" and "no trust" options, then a person should trust everyone in this potentially long chain. The problem is that trust is rarely a complete trust, there is a certain probability of distrust. So, when the chain becomes long, the probability of a security leak increases. It is desirable to keep …

Computing The Cube Of An Interval Matrix Is Np-Hard, Olga Kosheleva, Vladik Kreinovich, Guenter Mayer, Hung T. Nguyen

Departmental Technical Reports (CS)

In many practical applications, we are interested in computing the product of given matrices and/or a power of a given matrix. In some cases, the initial matrices are only known with interval uncertainty. It turns out that under this uncertainty, there is a principal difference between the product of two matrices and the product of three (or more) matrices:

on the one hand, it is more or less known that the problems of computing the exact range for the product of two matrices -- and for the square of a matrix -- are computationally feasible;

on the other hand, we …

Foundations Of Statistical Processing Of Set-Valued Data: Towards Efficient Algorithms, Hung T. Nguyen, Vladik Kreinovich, Gang Xiang

Departmental Technical Reports (CS)

Due to measurement uncertainty, often, instead of the actual values xi of the measured quantities, we only know the intervals [Xi]=[Xi-Di,Xi+Di], where Xi is the measured value and Di is the upper bound on the measurement error (provided, e.g., by the manufacturer of the measuring instrument). These intervals can be viewed as random intervals, i.e., as samples from the interval-valued random variable. In such situations, instead of the exact value of a sample statistic such as covariance C(x,y), we can only have an interval [C](x,y) of possible values of this statistic.

In this paper, we extend the foundations of traditional …

Deep-Sea Image Processing, Yuri Rzhanov, Larry A. Mayer, D J. Fornari

Center for Coastal and Ocean Mapping

High-resolution seafloor mapping often requires optical methods of sensing, to confirm interpretations made from sonar data. Optical digital imagery of seafloor sites can now provide very high resolution and also provides additional cues, such as color information for sediments, biota and divers rock types. During the cruise AT11-7 of the Woods Hole Oceanographic Institution (WHOI) vessel R/V Atlantis (February 2004, East Pacific Rise) visual imagery was acquired from three sources: (1) a digital still down-looking camera mounted on the submersible Alvin, (2) observer-operated 1-and 3-chip video cameras with tilt and pan capabilities mounted on the front of Alvin, and (3) …

A Tail-Recursive Machine With Stack Inspection, John Clements, Mathias Felleisen

Computer Science and Software Engineering

Security folklore holds that a security mechanism based on stack inspection is incompatible with a global tail call optimization policy; that an implementation of such a language must allocate memory for a source-code tail call, and a program that uses only tail calls (and no other memory allocating construct) may nevertheless exhaust the available memory. In this article, we prove this widely held belief wrong.We exhibit an abstract machine for a language with security stack inspection whose space consumption function is equivalent to that of the canonical tail call optimizing abstract machine. Our machine is surprisingly simple and suggests that …

Improvement Of Parameter Estimation For Non-Linear Hysteretic Systems With Slip By A Fast Bayesian Bootstrap Filter, S. J. Li, Yoshiyuki Suzuki, Mohammad N. Noori

Office of the Dean (CENG) Scholarship

Modeling and identification of non-linear hysteretic systems are widely encountered in the structural dynamics field, especially for the hysteresis with slip. A model, called SL model, which can describe the pinching of most practical hysteresis loops perfectly was proposed by Baber and Noori (J. Eng. Mech. 111 (1985) 1010). A method of estimating the parameters of SL model on the basis of input–output data based on bootstrap filter was proposed by the writers. Bootstrap filter is a filtering method based on Bayesian state estimation and Monte Carlo method, which has the great advantage of being able to handle any functional …