Statistics and Probability Commons^™

A Note On The Sub-Optimality Of Rank Ordering Of Objects On The Basis Of The Leading Principal Component Factor Scores, Sudhanshu K. Mishra

Sudhanshu K Mishra

This paper demonstrates that if we intend to optimally rank order n objects (candidates) each of which has m rank-ordered attributes or rank scores have been awarded by m evaluators, then the overall ordinal ranking of objects by the conventional principal component based factor scores turns out to be suboptimal. Three numerical examples have been provided to show that principal component based rankings do not necessarily maximize the sum of squared correlation coefficients between the individual m rank scores arrays, X(n,m), and overall rank scores array, Z(n).

Corso Di Analisi Delle Serie Storiche A.A 2008/2009- Laboratorio Di Stata: Lezione 3 –Analisi Classica Delle Serie Storiche I (Formato Pdf), Carlo Drago

Carlo Drago

No abstract provided.

Corso Di Analisi Delle Serie Storiche A.A 2008/2009- Laboratorio Di Stata: Lezione 2 - Costruzione Di Datasets Temporali, Trasformazioni E Analisi Grafica (Formato Pdf), Carlo Drago

Carlo Drago

No abstract provided.

Choosing Among Unequals: A Statistical Solution To A Stalemate, Durgesh Chandra Pathak

Durgesh Chandra Pathak

In Uttar Pradesh, a new tradition has been started of selecting B.Ed degree holders for a job in Primary Schools and it has been named "Vishisht BTC". Applying their own logic, the ruling governments use variuos criterion to select the candidates. The basic problem is that they have to choose candidates on the basis of merit of their marks in various exams. Now, it is well-established fact that marking is not similar in all universities/colleges. So for a same exam, there can be much inter-university as well as intra-university variation in marks given to students. The point is that student …

More Powerful Exact Noninferiority And Equivalence Tests Based On Binary Matched Pairs, Chris Lloyd

Chris J. Lloyd

Assessing the therapeutic noninferiority or equivalence of one medical treatment compared to another is often based on the difference of response rates from a matched binary pairs design. This paper develops new exact unconditional tests for noninferiority and equivalence that are more powerful than available alternatives. There are three new elements presented in this paper. First we introduce the LR statistic as an alternative to the previously proposed score statistic of Nam (1997). Second, we eliminate the nuisance parameter by estimation followed by maximization as an alternative to the partial maximization of Berger and Boos (1994) or traditional full maximization. …

Corso Di Analisi Delle Serie Storiche A.A 2008/2009- Laboratorio Di Stata: Lezione 1 - Operazioni Di Base (Formato Pdf), Carlo Drago

Carlo Drago

No abstract provided.

Finding Recurrent Regions Of Copy Number Variation: A Review, Oscar M. Rueda, Ramon Diaz-Uriarte

Ramon Diaz-Uriarte

Copy number alterations (CNA) in genomic DNA are linked to a variety of human diseases. Although many methods have been developed to analyze data from a single subject, disease-critical genes are more likely to be found in regions that are common or recurrent among diseased subjects. Unfortunately, finding recurrent CNA regions remains a challenge. We review existing methods for the identification of recurrent CNA regions. Methods differ in their working definition of ``recurrent region'', the type of input data, the statistical and computational methods used to identify recurrence, and the biological considerations they incorporate (which play a role in the …

Regressing Scalar Outcomes On Image Predictors Via Functional Principal Component Regression, Philip T. Reiss

Philip T. Reiss

No abstract provided.

Survival Unchanged Five Months After Implementing The 2005 Aha Cpr And Ecc Guidelines For Out-Of-Hospital Cardiac Arrest., Blair L. Bigham, Kent M. Koprowicz, John Stouffer, Tom P. Aufderheide, Stuart Donn, Judy Powell, Dan Davis, Sarah Nafziger, Brian Suffoletto, Ahamed Idris, Mike Helbock, Laurie J. Morrison

Kent M Koprowicz

Introduction: To improve survival from out of hospital cardiac arrest (OHCA), the American Heart Association released guidelines in 2005. We examined the effect of these guidelines on survival in the Resuscitation Outcomes Consortium (ROC) Epistry – Cardiac Arrest. We hypothesized that survival would increase after guideline implementation. Methods: 174 EMS agencies from 8 of the 10 ROC sites were surveyed to determine 2005 AHA guideline implementation, or crossover, date. Two sites with 2005 compatible treatment algorithms prior to guideline release were not included. Patients with OHCA secondary to a non cardiac cause, EMS witnessed events, patients <18 years>old, and patients with …

Una Comparazione Tra Le Reti Di Amministratori Nelle Principali Societa Quotate In Italia, Francia E Gran Bretagna, Paolo Santella, Carlo Drago, Andrea Polo, Enrico Gagliardi

Carlo Drago

The purpose of the present paper is to contribute to the empirical literature on country interlocks by illustrating and analysing the interlocking directorships in the first 40 Italian, French and British Blue Chips as of December 2007 (Italy)/March 2008 (France and uk). The theoretical literature identify two possible explanations for interlocking directorships, on the one hand the collusion among players in the same market or in general among enterprises that have business relations among themselves; on the other hand the interest for enterprises to have on their boards bankers, suppliers, and clients so as to reduce information asymmetries. Our findings …

Asymptotic Behavior Of Linearized Viscoelastic Flow Problem, Yinnian He, Yi Li

Yi Li

In this article, we provide some asymptotic behaviors of linearized viscoelastic flows in a general two-dimensional domain with certain parameters small and the time variable large.

Composite Endpoint Analysis For Assessing Surrogacy With Censored Data, Debashis Ghosh

Debashis Ghosh

Background: There is great interest in the development of surrogate endpoints using new technologies in medical research. The promise of such endpoints is that they would allow for faster completion of clinical trials and would be potentially cost-effective.

Purpose: In determining surrogacy, it is important to distinguish the roles of surrogate from the true endpoint. The latter should be thought of as the gold standard. We discuss a framework in which the utility of a surrogate endpoint is based on whether or not as part of a composite endpoint, it yields treatment effects that associate with that on the true …

The Economic Value Of Improved Environmental Health In Victorian Rivers, Chris Lloyd

Chris J. Lloyd

The non market valuation technique known as choice modelling was used to general benefit estimates for a selection of hypothetical environmental improvements Victorian Rivers. Monetary values were estimated for four attributed of improvements. The relevance of the approach to management and policy issues is demonstrated.

Estimated P-Values In Discrete Models: Asymptotic And Non-Asymptotic Effects, Chris Lloyd

Chris J. Lloyd

The exact null distribution of a P-value typically depends on nuisance parameters unspecified under the null. For discrete models and standard approximate P-values, this dependence can be quite strong. The estimated (or bootstrap) P-value is the exact probability of the P-value being no larger than its observed value, with the null estimate of the nuisance parameter substituted. For continuous models, it is known that such `bootstrap' P-values deviate from uniformity by terms of order m^{-3/2}, where m is a measure of sample size. The main difficulty with discrete models is the breakdown of asymptotics near the boundary. The aim of …

More Powerful Exact Tests Of Equivalence, Chris Lloyd

Chris J. Lloyd

In randomized clinical trials, it is often required to demonstrate that a new medical treatment is neither substantially worse nor better than a standard reference treatment. Formal testing of such `equivalence hypotheses' is typcialyl done by combining two one-sided tests (TOST). A quite diferent strand of research has demonstrated that maximising P-values over nuisance parameters produces optimal tests (Rohmel and Mansmann (1999) and Lloyd (2008a)). In this paper we point out that, even if the one-sided tests are exact and optimal, the TOST will generally be conservative and requires a further adjustment to remove this conservatism. The appropriate procedure is …

Factors Influencing Farmers’ Willingness To Protect Groundwater From Nonpoint Sources Of Pollution In The Lower Bhavani River Basin, Tamil Nadu, India, Sacchidananda Mukherjee

Sacchidananda Mukherjee

Farmers' perceptions about groundwater and drinking water quality are important, which influence their willingness to adopt protection measures either individually or collectively. This study attempts to capture the factors influencing farmers’ perceptions and their willingness to protect groundwater from nonpoint sources of pollution, and their willingness to support the local government to supply drinking water through alternative arrangements. Six villages are identified in the Lower Bhavani River Basin, Tamil Nadu, India on the basis of their long-term groundwater nitrate concentrations and sources of irrigation. A pre-structured questionnaire survey (face-to-face interviews) has been administered to 395 farm-households across six villages during …

Worldwide Variation In The Doubling Time Of Alzheimer's Disease Incidence Rates, Kathryn Ziegler-Graham, Ron Brookmeyer, Elizabeth Johnson, H. Michael Arrighi

Ron Brookmeyer

Background The doubling time is the number of chronological years for the age-specific incidence rate to double in magnitude. Doubling times describe the rate of increase of the risk of Alzheimer's disease (AD) with advancing age. Estimates of doubling times of AD assist in understanding disease etiology and forecasting future disease prevalence. The objective of this study was to investigate regional and gender differences in the doubling of AD age-specific incidence rates.

Methods We identified all studies in the peer review literature that reported age-specific incidence rates for AD. We modeled the logarithm of the incidence rate as a linear …

Simultaneous Confidence Bands For The Coefficient Function In Functional Regression, Philip T. Reiss

Philip T. Reiss

No abstract provided.

A One-Hour Training Seminar On Bayesian Statistics For Nursing Graduate Students, Byron J. Gajewski, Stephen D. Simon

Byron J Gajewski

In this paper we discuss one-way ANOVA with the goal of introducing Bayesian statistics to nursing graduate students in a one-hour seminar. We use ANOVA as it is arguably one of the most widely used statistical models in practice, and that its Bayesian treatment has interesting ties to the classical ANOVA, creating a smooth transition for students in a frequentist-based course to be introduced to Bayesian ideas. We discuss the limitations of this seminar in the context of our assumptions of what the students can or cannot do. An example from nursing research is used throughout the seminar.

Significant Figures, Tony Badrick, Peter Hickman

Tony Badrick

For consistency of reporting the same number of significant figures should be used for results and reference intervals. The choice of the reporting interval should be based on analytical imprecision (measurement uncertainty).

Inferring Group Differences In Brain Connectivity From Functional Magnetic Resonance Images, Philip T. Reiss

Philip T. Reiss

No abstract provided.

Reliability Of Functional Connectivity Networks: How Can We Assess It?, Philip T. Reiss

Philip T. Reiss

No abstract provided.

On Correcting The Overestimation Of The Permutation Based False Discovery Rate Estimator., Shuo Jiao, Shunpu Zhang

Shuo Jiao

Motivation: Recent attempts to account for multiple testing in the analysis of microarray data have focused on controlling the false discovery rate (FDR), which is defined as the expected percentage of the number of false positive genes among the claimed significant genes. As a consequence, the accuracy of the FDR estimators will

be important for correctly controlling FDR. Xie et al. found that the standard permutation method of estimating FDR is biased and proposed to delete the predicted differentially expressed (DE) genes in the estimation of FDR for one-sample comparison. However, we notice that the formula of the FDR used …

Locally Adaptive Nonparametric Binary Regression, Sally Wood, Martin Tanner, Wenxin Jiang, Robert Kohn, Remy Cottet

Sally Wood

No abstract provided.

Is Reporting On Interventions A Weak Link In Understanding How And Why They Work? A Preliminary Exploration Using Community Heart Health Exemplars, Barbara Riley, Joanne Macdonald, Omaima Mansi, Anita Kothari, Donna Kurtz, Linda Vontettenborn, Nancy Edwards

Anita Kothari

Background: The persistent gap between research and practice compromises the impact of multi-level and multi-strategy community health interventions. Part of the problem is a limited understanding of how and why interventions produce change in population health outcomes. Systematic investigation of these intervention processes across studies requires sufficient reporting about interventions. Guided by a set of best processes related to the design, implementation, and evaluation of community health interventions, this article presents preliminary findings of intervention reporting in the published literature using community heart health exemplars as case examples.

Methods: The process to assess intervention reporting involved three steps: selection of …

Economic Valuation Of A Wetland In West Bengal, India, Sacchidananda Mukherjee

Sacchidananda Mukherjee

In the Gangetic flood plain of West Bengal, wetlands are used for multiple purposes, and have significant role in the livelihoods of the local people. Over the years, these Multiple Use Systems (MUSs) are getting converted to single use systems due to economic and social pressure from dominant stakeholders, which are higher than that in single use systems. Economic and ecological functions of MUS changes over time and space. These dynamic aspects of MUS are often not fully appreciated. Attempts to classify wetlands according to their uses across ecological zones and to do their economic valuation are very limited. Based …

Docketology, District Courts, And Doctrine, David A. Hoffman, Alan J. Izenman, Jeffrey R. Lidicker

David A Hoffman

Empirical legal scholars have traditionally modeled judicial opinion writing by assuming that judges act rationally, seeking to maximize their influence by writing opinions in politically important cases. Support for this hypothesis has reviewed published opinions, finding that civil rights and other “hot” topics are more to be discussed than other issues. This orthodoxy comforts consumers of legal opinions, because it suggests that opinions are largely representative of judicial work. The orthodoxy is substantively and methodologically flawed. This paper starts by assuming that judges are generally risk averse with respect to reversal, and that they provide opinions when they believe that …

Bayesian Identification, Selection And Estimation Of Functions In High-Dimensional Additive Models, Anastasios Panagiotelis, Michael Smith

Michael Stanley Smith

In this paper we propose an approach to both estimate and select unknown smooth functions in an additive model with potentially many functions. Each function is written as a linear combination of basis terms, with coefficients regularized by a proper linearly constrained Gaussian prior. Given any potentially rank deficient prior precision matrix, we show how to derive linear constraints so that the corresponding effect is identified in the additive model. This allows for the use of a wide range of bases and precision matrices in priors for regularization. By introducing indicator variables, each constrained Gaussian prior is augmented with a …

Proceedings From Scientific Conference On Green Energy And It, Dr. Erik Dahlquist

Dr. Erik Dahlquist

This conference is part of the annual Energitinget, a national arena for energy in Sweden, with some 2500 participants. The focus with this session is to give a forum for researchers to present scientific results, and also to discuss these with other researchers. It contains papers in the area of Energy and IT as well as Green energy generally

Efficient Mean Estimation In Log-Normal Linear Models, Haipeng Shen, Zhengyuan Zhu

Zhengyuan Zhu