A Power Comparison of Robust Tests for Monotonic Trends in Recurrent Events

A Power Comparison of Robust Tests for Monotonic Trends in Recurrent Events PDF Author: Jiajia Yue
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The analysis of the existence and form of time trends in repairable systems is an important issue in reliability studies. Hence, many trend tests have been proposed and studied in the literature. There has been a recent interest in the use of robust trend tests based on estimating functions to test the absence of time trends in the rate functions of recurrent event processes. These tests are appealing because they do not require strong assumptions about the nature of the processes, and are powerful in a wide range of settings. In this study, we consider monotone time trends in recurrent event data from repairable systems, and develop a robust trend test based on rate functions of the power law processes. Our main goal is to discuss the power of robust trend tests as well as to compare their power with other well-known trend tests under various settings. We therefore conducted extensive Monte Carlo simulations to compute and compare the power of these tests under various scenarios. Finally, we analyze two data sets from industry to illustrate the methodology.

A Power Comparison of Robust Tests for Monotonic Trends in Recurrent Events

A Power Comparison of Robust Tests for Monotonic Trends in Recurrent Events PDF Author: Jiajia Yue
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
The analysis of the existence and form of time trends in repairable systems is an important issue in reliability studies. Hence, many trend tests have been proposed and studied in the literature. There has been a recent interest in the use of robust trend tests based on estimating functions to test the absence of time trends in the rate functions of recurrent event processes. These tests are appealing because they do not require strong assumptions about the nature of the processes, and are powerful in a wide range of settings. In this study, we consider monotone time trends in recurrent event data from repairable systems, and develop a robust trend test based on rate functions of the power law processes. Our main goal is to discuss the power of robust trend tests as well as to compare their power with other well-known trend tests under various settings. We therefore conducted extensive Monte Carlo simulations to compute and compare the power of these tests under various scenarios. Finally, we analyze two data sets from industry to illustrate the methodology.

Statistical Methods in Water Resources

Statistical Methods in Water Resources PDF Author: D.R. Helsel
Publisher: Elsevier
ISBN: 0080875084
Category : Science
Languages : en
Pages : 539

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Book Description
Data on water quality and other environmental issues are being collected at an ever-increasing rate. In the past, however, the techniques used by scientists to interpret this data have not progressed as quickly. This is a book of modern statistical methods for analysis of practical problems in water quality and water resources. The last fifteen years have seen major advances in the fields of exploratory data analysis (EDA) and robust statistical methods. The 'real-life' characteristics of environmental data tend to drive analysis towards the use of these methods. These advances are presented in a practical and relevant format. Alternate methods are compared, highlighting the strengths and weaknesses of each as applied to environmental data. Techniques for trend analysis and dealing with water below the detection limit are topics covered, which are of great interest to consultants in water-quality and hydrology, scientists in state, provincial and federal water resources, and geological survey agencies. The practising water resources scientist will find the worked examples using actual field data from case studies of environmental problems, of real value. Exercises at the end of each chapter enable the mechanics of the methodological process to be fully understood, with data sets included on diskette for easy use. The result is a book that is both up-to-date and immediately relevant to ongoing work in the environmental and water sciences.

Statistical Methods for Trend Detection and Analysis in the Environmental Sciences

Statistical Methods for Trend Detection and Analysis in the Environmental Sciences PDF Author: Richard Chandler
Publisher: John Wiley & Sons
ISBN: 111999196X
Category : Mathematics
Languages : en
Pages : 348

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Book Description
The need to understand and quantify change is fundamental throughout the environmental sciences. This might involve describing past variation, understanding the mechanisms underlying observed changes, making projections of possible future change, or monitoring the effect of intervening in some environmental system. This book provides an overview of modern statistical techniques that may be relevant in problems of this nature. Practitioners studying environmental change will be familiar with many classical statistical procedures for the detection and estimation of trends. However, the ever increasing capacity to collect and process vast amounts of environmental information has led to growing awareness that such procedures are limited in the insights that they can deliver. At the same time, significant developments in statistical methodology have often been widely dispersed in the statistical literature and have therefore received limited exposure in the environmental science community. This book aims to provide a thorough but accessible review of these developments. It is split into two parts: the first provides an introduction to this area and the second part presents a collection of case studies illustrating the practical application of modern statistical approaches to the analysis of trends in real studies. Key Features: Presents a thorough introduction to the practical application and methodology of trend analysis in environmental science. Explores non-parametric estimation and testing as well as parametric techniques. Methods are illustrated using case studies from a variety of environmental application areas. Looks at trends in all aspects of a process including mean, percentiles and extremes. Supported by an accompanying website featuring datasets and R code. The book is designed to be accessible to readers with some basic statistical training, but also contains sufficient detail to serve as a reference for practising statisticians. It will therefore be of use to postgraduate students and researchers both in the environmental sciences and in statistics.

The R Book

The R Book PDF Author: Michael J. Crawley
Publisher: John Wiley & Sons
ISBN: 9780470515068
Category : Mathematics
Languages : en
Pages : 953

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Book Description
The high-level language of R is recognized as one of the mostpowerful and flexible statistical software environments, and israpidly becoming the standard setting for quantitative analysis,statistics and graphics. R provides free access to unrivalledcoverage and cutting-edge applications, enabling the user to applynumerous statistical methods ranging from simple regression to timeseries or multivariate analysis. Building on the success of the author’s bestsellingStatistics: An Introduction using R, The R Book ispacked with worked examples, providing an all inclusive guide to R,ideal for novice and more accomplished users alike. The bookassumes no background in statistics or computing and introduces theadvantages of the R environment, detailing its applications in awide range of disciplines. Provides the first comprehensive reference manual for the Rlanguage, including practical guidance and full coverage of thegraphics facilities. Introduces all the statistical models covered by R, beginningwith simple classical tests such as chi-square and t-test. Proceeds to examine more advance methods, from regression andanalysis of variance, through to generalized linear models,generalized mixed models, time series, spatial statistics,multivariate statistics and much more. The R Book is aimed at undergraduates, postgraduates andprofessionals in science, engineering and medicine. It is alsoideal for students and professionals in statistics, economics,geography and the social sciences.

Mathematical and Statistical Methods in Reliability

Mathematical and Statistical Methods in Reliability PDF Author: Bo Lindqvist
Publisher: World Scientific
ISBN: 9812383212
Category : Mathematics
Languages : en
Pages : 569

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Book Description
This book contains extended versions of carefully selected and reviewed papers presented at the Third International Conference on Mathematical Methods in Reliability, held in Norway in 2002. It provides an overview of current research activities in reliability theory. The authors are all leading experts in the field. Readership: Graduate students, academics and professionals in probability & statistics, reliability analysis, survival analysis, industrial engineering, software engineering, operations research and applied mathematics research.

Time Series Modelling of Water Resources and Environmental Systems

Time Series Modelling of Water Resources and Environmental Systems PDF Author: K.W. Hipel
Publisher: Elsevier
ISBN: 0080870368
Category : Technology & Engineering
Languages : en
Pages : 1053

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Book Description
This is a comprehensive presentation of the theory and practice of time series modelling of environmental systems. A variety of time series models are explained and illustrated, including ARMA (autoregressive-moving average), nonstationary, long memory, three families of seasonal, multiple input-single output, intervention and multivariate ARMA models. Other topics in environmetrics covered in this book include time series analysis in decision making, estimating missing observations, simulation, the Hurst phenomenon, forecasting experiments and causality. Professionals working in fields overlapping with environmetrics - such as water resources engineers, environmental scientists, hydrologists, geophysicists, geographers, earth scientists and planners - will find this book a valuable resource. Equally, environmetrics, systems scientists, economists, mechanical engineers, chemical engineers, and management scientists will find the time series methods presented in this book useful.

Multiple Comparisons Using R

Multiple Comparisons Using R PDF Author: Frank Bretz
Publisher: CRC Press
ISBN: 1420010905
Category : Mathematics
Languages : en
Pages : 202

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Book Description
Adopting a unifying theme based on maximum statistics, Multiple Comparisons Using R describes the common underlying theory of multiple comparison procedures through numerous examples. It also presents a detailed description of available software implementations in R. The R packages and source code for the analyses are available at http://CRAN.R-project.org After giving examples of multiplicity problems, the book covers general concepts and basic multiple comparisons procedures, including the Bonferroni method and Simes’ test. It then shows how to perform parametric multiple comparisons in standard linear models and general parametric models. It also introduces the multcomp package in R, which offers a convenient interface to perform multiple comparisons in a general context. Following this theoretical framework, the book explores applications involving the Dunnett test, Tukey’s all pairwise comparisons, and general multiple contrast tests for standard regression models, mixed-effects models, and parametric survival models. The last chapter reviews other multiple comparison procedures, such as resampling-based procedures, methods for group sequential or adaptive designs, and the combination of multiple comparison procedures with modeling techniques. Controlling multiplicity in experiments ensures better decision making and safeguards against false claims. A self-contained introduction to multiple comparison procedures, this book offers strategies for constructing the procedures and illustrates the framework for multiple hypotheses testing in general parametric models. It is suitable for readers with R experience but limited knowledge of multiple comparison procedures and vice versa. See Dr. Bretz discuss the book.

Statistical Methods for Environmental Pollution Monitoring

Statistical Methods for Environmental Pollution Monitoring PDF Author: Richard O. Gilbert
Publisher: John Wiley & Sons
ISBN: 9780471288787
Category : Technology & Engineering
Languages : en
Pages : 354

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Book Description
This book discusses a broad range of statistical design and analysis methods that are particularly well suited to pollution data. It explains key statistical techniques in easy-to-comprehend terms and uses practical examples, exercises, and case studies to illustrate procedures. Dr. Gilbert begins by discussing a space-time framework for sampling pollutants. He then shows how to use statistical sample survey methods to estimate average and total amounts of pollutants in the environment, and how to determine the number of field samples and measurements to collect for this purpose. Then a broad range of statistical analysis methods are described and illustrated. These include: * determining the number of samples needed to find hot spots * analyzing pollution data that are lognormally distributed * testing for trends over time or space * estimating the magnitude of trends * comparing pollution data from two or more populations New areas discussed in this sourcebook include statistical techniques for data that are correlated, reported as less than the measurement detection limit, or obtained from field-composited samples. Nonparametric statistical analysis methods are emphasized since parametric procedures are often not appropriate for pollution data. This book also provides an illustrated comprehensive computer code for nonparametric trend detection and estimation analyses as well as nineteen statistical tables to permit easy application of the discussed statistical techniques. In addition, many publications are cited that deal with the design of pollution studies and the statistical analysis of pollution data. This sourcebook will be a useful tool for applied statisticians, ecologists, radioecologists, hydrologists, biologists, environmental engineers, and other professionals who deal with the collection, analysis, and interpretation of pollution in air, water, and soil.

Analysis of Climate Variability

Analysis of Climate Variability PDF Author: Hans v. Storch
Publisher: Springer Science & Business Media
ISBN: 3662031671
Category : Science
Languages : en
Pages : 336

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Book Description
EUROPEAN SCHOOl OF CLiMATOlOGY AND NATURAL HAZARDS The training of scientific and technical personnel and the development of highly qualified scientists are, and have always been, among the important concerns of the European Commission. Advanced training is an important requirement for the implementation of a common EU policy in science and technology. The European School of Climatology and Natural Hazards was started as apart of the training and education activities of the European Programme on Climatology and Natural Hazards (EPOCH), and is continued under the subsequent research programme (ENVIRONMENT 1990-1994). The school consists of annual courses on specialised subjects within re search in climatology and natural hazards, and is open to graduating, grad uate and post graduate students in these fields. Each of the courses is organized in cooperation with a European Institu tion involved in the current research programme, and is aimed at giving to the students formal lectures and participation in informal discussions with leading researchers. The present volume is based on the lectures given at the course held on the island of Elba from the 30th October to the 6th of November 1993 on Statistical Analysis of Climate Variability. It features selected and extended presentations, and represents an important contribution to advanced studies in climate statistical analysis, supplementing more traditional texts. I trust that all those involved in research related to climate change and climate variability will appreciate this work and will benefit from the com prehensive and state-of-the-art information it provides.

Advances in Time Series Methods and Applications

Advances in Time Series Methods and Applications PDF Author: Wai Keung Li
Publisher: Springer
ISBN: 1493965689
Category : Business & Economics
Languages : en
Pages : 298

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Book Description
This volume reviews and summarizes some of A. I. McLeod's significant contributions to time series analysis. It also contains original contributions to the field and to related areas by participants of the festschrift held in June 2014 and friends of Dr. McLeod. Covering a diverse range of state-of-the-art topics, this volume well balances applied and theoretical research across fourteen contributions by experts in the field. It will be of interest to researchers and practitioners in time series, econometricians, and graduate students in time series or econometrics, as well as environmental statisticians, data scientists, statisticians interested in graphical models, and researchers in quantitative risk management.