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Full-Text Articles in Statistics and Probability

Jacques Salomon Hadamard And The Use Of Symbols In Teaching Differential Calculus, Daniel S. Drucker, Claude Schochet, John Cuzzocrea, Shlomo Sawilowsky May 2008

Jacques Salomon Hadamard And The Use Of Symbols In Teaching Differential Calculus, Daniel S. Drucker, Claude Schochet, John Cuzzocrea, Shlomo Sawilowsky

Journal of Modern Applied Statistical Methods

Scripta Universitatis, edited by Albert Einstein and first published in 1923, played a significant role in the establishment of Hebrew University in Jerusalem. Articles appeared on the left half of the journal in the author’s chosen language and they were translated into Hebrew on the right half. The inaugural issue contained an article by the French mathematician Jacques Hadamard (8 December 1865 – 17 October 1963). Y. Wolfson of Kharkov translated it into Hebrew. An English translation is presented here, along with scans of the original first pages that were published in French and Hebrew. Documents pertaining to the …


On Measuring The Relative Importance Of Explanatory Variables In A Logistic Regression , D. Roland Thomas, Pengcheng Zhu, Bruno D. Zumbo, Shantanu Dutta May 2008

On Measuring The Relative Importance Of Explanatory Variables In A Logistic Regression , D. Roland Thomas, Pengcheng Zhu, Bruno D. Zumbo, Shantanu Dutta

Journal of Modern Applied Statistical Methods

A search is described for valid methods of assessing the importance of explanatory variables in logistic regression, motivated by earlier work on the relationship between corporate governance variables and the issuance of restricted voting shares (RSF). The methods explored are adaptations of Pratt’s (1987) approach for measuring variable importance in simple linear regression, which is based on a special partition of R2. Pseudo-R2 measures for logistic regression are briefly reviewed, and two measures are selected which can be partitioned in a manner analogous to that used by Pratt. One of these is ultimately selected for the variable …


Using Exploratory Factor Analysis For Locating Invariant Referents In Factor Invariance Studies, W. Holmes Finch, Brian F. French May 2008

Using Exploratory Factor Analysis For Locating Invariant Referents In Factor Invariance Studies, W. Holmes Finch, Brian F. French

Journal of Modern Applied Statistical Methods

Model identification in multi-group confirmatory factor analysis (MCFA) requires an equality constraint of referent variables across groups. Invariance assumption violations make it difficult to locate parameters that actually differ. Suggested procedures for locating invariant referents are cumbersome, complex, and provide imperfect results. Exploratory factor analysis (EFA) may be an alternative because of its ease of use, yet empirical evaluation of its effectiveness is lacking. EFAs accuracy for distinguishing invariant from non-invariant referents was examined.


Probability Of Coverage And Interval Length For Two-Group Techniques Assessing The Median And Trimmed Mean, S. Jonathan Mends-Cole May 2008

Probability Of Coverage And Interval Length For Two-Group Techniques Assessing The Median And Trimmed Mean, S. Jonathan Mends-Cole

Journal of Modern Applied Statistical Methods

The purpose of the present study was to assess the probability of coverage and interval length of selected statistical techniques that have a higher finite sample breakdown point than the mean and appropriate levels of probability of coverage when using Bradley’s (1978) criterion. The techniques were examined using real education and psychology datasets (Sawilowsky & Fahoome, 2003, Sawilowsky & Blair, 1992). Welch’s test exhibited appropriate coverage for the smooth symmetric, mass at zero, digit preference, and extreme bimodal distributions. Yuen’s technique performed well under an extreme bimodal distribution. Results concerning the Maritz-Jarrett and the McKean-Schrader techniques are also presented.


Test For Spatio-Temporal Counts Being Poisson, Haiyan Chen, Howard H. Stratton May 2008

Test For Spatio-Temporal Counts Being Poisson, Haiyan Chen, Howard H. Stratton

Journal of Modern Applied Statistical Methods

The new Log-Linear Test (TL) is proposed to identify when the Poisson model fails for a collection of count random variables. TL is shown to have better rejection rate with small sample size and essentially the same power compared to a classical Fisher-Bohning’s Statistic TF for standard alternatives to Poisson.


Measuring Overall Heterogeneity In Meta-Analyses: Application To Csf Biomarker Studies In Alzheimer’S Disease, Chengjie Xiong, Feng Gao, Yan Yan, Jingqin Luo, Yunju Sung, Gang Shi May 2008

Measuring Overall Heterogeneity In Meta-Analyses: Application To Csf Biomarker Studies In Alzheimer’S Disease, Chengjie Xiong, Feng Gao, Yan Yan, Jingqin Luo, Yunju Sung, Gang Shi

Journal of Modern Applied Statistical Methods

The interpretations of statistical inferences from meta-analyses depend on the degree of heterogeneity in the meta-analyses. Several new indices of heterogeneity in meta-analyses are proposed, and assessed the variation/difference of these indices through a large simulation study. The proposed methods are applied to biomakers of Alzheimer’s disease.


When Sensitivity Is A Function Of Age And Time Spent In The Preclinical State In Periodic Cancer Screening, Dongfeng Wu, Ricolindo L. Cariño, Xiaoqin Wu May 2008

When Sensitivity Is A Function Of Age And Time Spent In The Preclinical State In Periodic Cancer Screening, Dongfeng Wu, Ricolindo L. Cariño, Xiaoqin Wu

Journal of Modern Applied Statistical Methods

Probability models are extended for periodic cancer screening trials to model sensitivity when it is changing with an individual’s age and time spent in the preclinical state. Wu et al. (2005) showed that sensitivity is monotone increasing with age, but intuitively, sensitivity is also a function of the time one has spent in the preclinical stage. This allows us to infer sensitivity at a late stage, just before symptoms manifest. We developed the probability model and applied Bayesian inference to the HIP study group data. The methodology we developed is also applicable to other kinds of chronic diseases.


Log-Linear Model To Assess Socioeconomic And Environmental Factors With Childhood Diarrhea Using Hospital Based Surveillance, Krishnan Rajendran, Thandavarayan Ramamurthy, Sujit Kumar Bhattacharya May 2008

Log-Linear Model To Assess Socioeconomic And Environmental Factors With Childhood Diarrhea Using Hospital Based Surveillance, Krishnan Rajendran, Thandavarayan Ramamurthy, Sujit Kumar Bhattacharya

Journal of Modern Applied Statistical Methods

Categorical outcomes with environment factors analyzed by log linear model are frequent in the environmental epidemiological literature. Epidemiological and socio-economical factors were obtained on 1,119 children below the age of 5 from Infectious Diseases Hospital (IDH) at the Kolkata, India. Significant associations of diarrhea were observed in the rural areas with family income, father’s occupation as a daily labor, literacy of parents, non-cemented floor and wall constructed of mud, and type of storage (wide mouthed earthen pot). The results of the study with specific Log linear model confirm environmental factors were important implications for childhood diarrhea in the rural community. …


Robust General Linear Models And Graphics Via A User Interface (Web Rglm), Kimberly Crimin, Asheber Abebe, Joseph W. Mckean May 2008

Robust General Linear Models And Graphics Via A User Interface (Web Rglm), Kimberly Crimin, Asheber Abebe, Joseph W. Mckean

Journal of Modern Applied Statistical Methods

Rank-based procedures provide superior estimation and testing techniques when the data deviate from normality or contain gross outliers. However, these robust techniques are rarely incorporated in a nonparametric statistics or methods courses due to the lack of computational tools. One reason for this is the existence of certain unavoidable complexities in the numerical methods due to the absence of a closedform solution for the rank estimation problem. This article introduces a user interface, Web RGLM, which may be used to perform rank-based analyses of linear models across the World Wide Web. These models include simple location problems to complicated ANOVA …


Effect On Recreation Benefit Estimates From Correcting For On-Site Sampling Biases And Heterogeneous Trip Overdispersion In Count Data Recreation Demand Models (Stata), Roberto Martínez-Espiñeira, Joseph M. Hilbe May 2008

Effect On Recreation Benefit Estimates From Correcting For On-Site Sampling Biases And Heterogeneous Trip Overdispersion In Count Data Recreation Demand Models (Stata), Roberto Martínez-Espiñeira, Joseph M. Hilbe

Journal of Modern Applied Statistical Methods

Correction procedures (STATA commands NBSTRAT and GNBSTRAT) are applied to simultaneously account for zero-truncation, endogenous stratification, and overdispersion, and also consider heterogeneity in the overdispersion parameter. Their effect is shown on welfare estimates from previous studies, confirming that the routines perform the appropriate correction and only when endogenous stratification is expected.


Computing Multivariate Process Capability Indices (Excel), Michele Scagliarini, Raffaele Vermiglio May 2008

Computing Multivariate Process Capability Indices (Excel), Michele Scagliarini, Raffaele Vermiglio

Journal of Modern Applied Statistical Methods

In manufacturing industry there is growing interest in measures of process capability under multivariate setting. Although there are many statistical packages to assess univariate capability, a current problem with the multivariate measures of capability is the shortage of user friendly software. In this article a Visual Basic program has been developed to realize an Excel spreadsheet that may be used to compute two multivariate measures of capability. The aim of this article is to provide a useful tool for practitioners dealing with multivariate capability assessment problems. The features of the program include easy data entry and clear report format.


Logit Estimation Using Warner’S Randomized Response Model, Zawar Hussain, Javid Shabbir May 2008

Logit Estimation Using Warner’S Randomized Response Model, Zawar Hussain, Javid Shabbir

Journal of Modern Applied Statistical Methods

A modified hidden logit estimation procedure is presented based on Warner (1965) randomized response model. Monte Carlo simulations explore the behavior of this estimator and compare its performance with the ordinary logits estimator. Warner’s model is more protective and less jeopardizing.


Estimation Of Covariance Matrix In Signal Processing When The Noise Covariance Matrix Is Arbitrary, Madhusudan Bhandary May 2008

Estimation Of Covariance Matrix In Signal Processing When The Noise Covariance Matrix Is Arbitrary, Madhusudan Bhandary

Journal of Modern Applied Statistical Methods

An estimator of the covariance matrix in signal processing is derived when the noise covariance matrix is arbitrary based on the method of maximum likelihood estimation. The estimator is a continuous function of the eigenvalues and eigenvectors of the matrix Σ̂11/2S∗Σ̂11/2, where S∗ is the sample covariance matrix of observations consisting of both noise and signals and Σ̂1 is the estimator of covariance matrix based on observations consisting of noise only. Strong consistency and asymptotic normality of the estimator are briefly discussed.


On The Length Of Nhl Shootouts, W. J. Hurley May 2008

On The Length Of Nhl Shootouts, W. J. Hurley

Journal of Modern Applied Statistical Methods

When NHL teams are tied after 60 minutes of regulation time and 5 minutes of sudden-death overtime, they go to a shootout to determine who gets the overtime point. Teams alternate shots until a winner is determined. The probability of observing shootouts of various lengths is calculated.


Mechanistic Home Range Models And Resource Selection Analysis: A Reconciliation And Unification, Paul R. Moorcroft, Alex Barnett Apr 2008

Mechanistic Home Range Models And Resource Selection Analysis: A Reconciliation And Unification, Paul R. Moorcroft, Alex Barnett

Dartmouth Scholarship

In the three decades since its introduction, resource selection analysis (RSA) has become a widespread method for analyzing spatial patterns of animal relocations obtained from telemetry studies. Recently, mechanistic home range models have been proposed as an alternative framework for studying patterns of animal space-use. In contrast to RSA models, mechanistic home range models are derived from underlying mechanistic descriptions of individual movement behavior and yield spatially explicit predictions for patterns of animal space-use. In addition, their mechanistic underpinning means that, unlike RSA, mechanistic home range models can also be used to predict changes in space-use following perturbation. In this …


Medical Progress Depends On Animal Models - Doesn't It?, Robert A. J. Matthews Feb 2008

Medical Progress Depends On Animal Models - Doesn't It?, Robert A. J. Matthews

Validation of Animal Experimentation Collection

Animal models are widely recognized as being essential to the progress of medical science. In countering the critics’ arguments of the use of animals in medicine, one statement has acquired almost talismanic importance:

‘Virtually every medical achievement of the last century has depended directly or indirectly on research with animals.’

In this essay, the origins and justification of this oft-repeated statement are examined. Despite its endorsement by leading academic bodies, it is far from clear that the statement has been, or even could be, formally validated.


Infant Feeding Decisions Among Pregnant Black Wic Participants And The Role Of Peer Support, Astrid D. Mickens Feb 2008

Infant Feeding Decisions Among Pregnant Black Wic Participants And The Role Of Peer Support, Astrid D. Mickens

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the important factors that impact infant feeding decisions among Black women, and to determine whether peer support influences the relationship among theoretical constructs of the social learning theory. A convenience sample of 110 Black pregnant women, ages 18-45, attending Women, Infant and Children (WIC) clinics throughout Riverside and San Bernardino Counties were recruited to participate in the study through the Nutrition Services Department. Eligible participants included pregnant Black WIC clients in any stage of pregnancy.

The survey questions contained information about perceived support, cognitive knowledge, abilities and beliefs regarding breastfeeding. The goal …


Differences In The Performance Of Knowledge Transfer Across Projects: A Study Of Gender And Role Of Key Project Stakeholders, Rafael E. Landaeta, Catherine Vergopia, Rey N. Diaz Jan 2008

Differences In The Performance Of Knowledge Transfer Across Projects: A Study Of Gender And Role Of Key Project Stakeholders, Rafael E. Landaeta, Catherine Vergopia, Rey N. Diaz

Engineering Management & Systems Engineering Faculty Publications

This investigation contributes empirical results of differences identified in key project stakeholders with respect to their use of knowledge transferred across projects. Gender and role were the two individual characteristics investigated. Project managers and members of project teams were the key stakeholders analyzed. Data was collected from 71 closed projects using a survey composed of closed-ended questions. The data collected was cross tabulated and statistically analyzed using Friedman's test and Spearman's correlation. The results provide evidence of the association of the performance of knowledge transfer across projects with (a) the individual factors of gender and role of key project stakeholders …


Multi-Algorithmic Cryptography Using Deterministic Chaos With Applications To Mobile Communications, Jonathan Blackledge Jan 2008

Multi-Algorithmic Cryptography Using Deterministic Chaos With Applications To Mobile Communications, Jonathan Blackledge

Articles

In this extended paper, we present an overview of the principal issues associated with cryptography, providing historically significant examples for illustrative purposes as part of a short tutorial for readers that are not familiar with the subject matter. This is used to introduce the role that nonlinear dynamics and chaos play in the design of encryption engines which utilize different types of Iteration Function Systems (IFS). The design of such encryption engines requires that they conform to the principles associated with diffusion and confusion for generating ciphers that are of a maximum entropy type. For this reason, the role of …


Changes In Poverty And Educational Attainment, 2000 To 2007 Poverty Rates Increasing For Those With College Education, Too, Mark Salling Jan 2008

Changes In Poverty And Educational Attainment, 2000 To 2007 Poverty Rates Increasing For Those With College Education, Too, Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.


Hispanics And Asians Increase In Numbers In Cuyahoga County An Analysis Of 2007 County Population Estimates, Mark Salling Jan 2008

Hispanics And Asians Increase In Numbers In Cuyahoga County An Analysis Of 2007 County Population Estimates, Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.


Application Of The Fractal Market Hypothesis For Modelling Macroeconomic Time Series, Jonathan Blackledge Jan 2008

Application Of The Fractal Market Hypothesis For Modelling Macroeconomic Time Series, Jonathan Blackledge

Articles

This paper explores the conceptual background to financial time series analysis and financial signal processing in terms of the Efficient Market Hypothesis. By revisiting the principal conventional approaches to market analysis and the reasoning associated with them, we develop a Fractal Market Hypothesis that is based on the application of non-stationary fractional dynamics using an operator of the type
∂2 / ∂x2 − σq(t) * ∂ q(t)/ ∂tq(t)

where σ−1 is the fractional diffusivity and q is the Fourier dimension which, for the topology considered, (i.e. the one-dimensional case) is related to the Fractal …


The Cleveland-Akron-Elyria Region Doing Well: More Persons Attending College And Getting Degrees, 2000 To 2007, Mark Salling Jan 2008

The Cleveland-Akron-Elyria Region Doing Well: More Persons Attending College And Getting Degrees, 2000 To 2007, Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

Discussions of economic development and job availability in northeast Ohio often lament the unavailability of a qualified workforce in some sectors. Workforce training and attracting more educated population to the region are sited as important, even critical, objectives for the region. While a more detailed study of the regions’ workforce by The Center for Community Solutions is nearing completion, the release of new data by the Census Bureau provides some enlightening observations about college enrollments and educational attainment in the region.


Ohio Continues To Lag In Population Growth And Comments On Prospects For The Future An Analysis Of 2007 State Population Estimates, Mark Salling Jan 2008

Ohio Continues To Lag In Population Growth And Comments On Prospects For The Future An Analysis Of 2007 State Population Estimates, Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

No abstract provided.


Wrongly Accused Redux: How Race Contributes To Convicting The Innocent: The Informants Example, Andrew E. Taslitz Jan 2008

Wrongly Accused Redux: How Race Contributes To Convicting The Innocent: The Informants Example, Andrew E. Taslitz

School of Law Faculty Publications

This article analyzes five forces that may raise the risk of convicting the innocent based upon the suspect's race: the selection, ratchet, procedural justice, bystanders, and aggressive-suspicion effects. In other words, subconscious forces press police to focus more attention on racial minorites, the ratchet makes this focus every-increasing, the resulting sense by the community of unfair treatment raises its involvment in crime while lowering its willingness to aid the police in resisting crime, innocent persons suffer when their skin color becomes associated with criminality, and the police use more aggressive techniques on racial minorities in a way that raises the …


Systematic Reviews Of Animal Experiments Demonstrate Poor Human Clinical And Toxicological Utility, Andrew Knight Dec 2007

Systematic Reviews Of Animal Experiments Demonstrate Poor Human Clinical And Toxicological Utility, Andrew Knight

Experimentation Collection

The assumption that animal models are reasonably predictive of human outcomes provides the basis for their widespread use in toxicity testing and in biomedical research aimed at developing cures for human diseases. To investigate the validity of this assumption, the comprehensive Scopus biomedical bibliographic databases were searched for published systematic reviews of the human clinical or toxicological utility of animal experiments. In 20 reviews in which clinical utility was examined, the authors concluded that animal models were either significantly useful in contributing to the development of clinical interventions, or were substantially consistent with clinical outcomes, in only two cases, one …


On The Total Duration Of Negative Surplus Of A Risk Process With Two-Step Premium Function, Pavlina Jordanova Dec 2007

On The Total Duration Of Negative Surplus Of A Risk Process With Two-Step Premium Function, Pavlina Jordanova

Applications and Applied Mathematics: An International Journal (AAM)

We consider a risk reserve process whose premium rate reduces from cd to cu when the reserve comes above some critical value v. In the model of Cramer-Lundberg with initial capital u ≥ 0, we obtain the probability that ruin does not occur before the first up-crossing of level v. When u < v, following H. Gerber and E. Shiu (1997), we derive the probability that starting with initial capital u ruin occurs and the severity of ruin is not bigger than v. Further we express the probability of ruin in the two step premium function model - ψ (u,v), by the last two probabilities. Our assumptions imply that the surplus process will go to infinity almost surely. This entails that the process will stay below zero only temporarily. We derive the distribution of the total duration of negative surplus and obtain its Laplace transform and mean value. As a consequence of these results, under certain conditions in the Model of Cramer-Lundberg we obtain the expected value of the severity of ruin. In the end of the paper we give examples with exponential claim sizes.


Efficacy Of Cognitive Therapy And Pharmacotherapy In Depression: A Meta-Analysis, Daniel B. Michel Dec 2007

Efficacy Of Cognitive Therapy And Pharmacotherapy In Depression: A Meta-Analysis, Daniel B. Michel

Loma Linda University Electronic Theses, Dissertations & Projects

A meta-analysis comparing the long-term effectiveness of cognitive behavioral therapy (CBT) and pharmacotherapy in preventing relapse following treatment discontinuation was performed using published studies of depressed participants. Twenty-three articles met inclusionary criteria and were included in the analyses. Weighted effect sizes and moderators, treatment type, were calculated using statistical analysis software. Initially, fixed effects models were applied to the data, but due to significant between-group heterogeneity that could not be fully explained by treatment type, mixed effect models were used to account for the residual heterogeneity. Results indicated that overall, depressed individuals treated to remission with CBT evidence decreased relapse …


A Study Of The Relationship Between American Evangelicals And Human Rights, Amy Rachel Timmons Stumpf Dec 2007

A Study Of The Relationship Between American Evangelicals And Human Rights, Amy Rachel Timmons Stumpf

Loma Linda University Electronic Theses, Dissertations & Projects

Human rights violations and abuses affect every region of the globe. The most recent Amnesty International Annual Report details violations in 149 countries. While there are no simple solutions to a problem of this magnitude and complexity, the support of powerful social groups can help in providing relief to the victims, pressure on abusive governments, legal consequences for abusers, and other resources in combating the violence that seems to chronically plague over our world. One of the most powerful groups, with tremendous social capital, is American evangelicals. Evangelicalism, even given the loose and informal organizational structures, is one of the …


An Omnibus Test When Using A Regression Estimator With Multiple Predictors, Rand R. Wilcox Nov 2007

An Omnibus Test When Using A Regression Estimator With Multiple Predictors, Rand R. Wilcox

Journal of Modern Applied Statistical Methods

In quantile regression, the goal is to estimate theγ quantile of Y given values for p predictors. Methods for making inferences about the individual slope parameters have been proposed, some of which have been found to perform very well in simulations. But for an omnibus test that all slope parameters are zero, it appears that little is known about how best to proceed. For the special case γ =.5, a drop-in-dispersion test has been recommended, but it requires a large sample size to control the probability of a Type I error and it assumes that the usual error term is …