n =10,220 observations. Smaller samples analyzed here to illustrate sample size effect.
|
|
- Cory Carr
- 5 years ago
- Views:
Transcription
1 Chapter 7 Parametric Likelihood Fitting Concepts: Chapter 7 Parametric Likelihood Fitting Concepts: Objectives Show how to compute a likelihood for a parametric model using discrete data. Show how to compute a likelihood for samples containing right censored observations and left censored observations. William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University Copyright W. Q. Meeker and L. A. Escobar. Based on the authors text Statistical Methods for Reliability Data, John Wiley & Sons Inc December 14, h 9min 7-1 Use a parametric likelihood as a tool for data analysis and inference. Illustrate the use of likelihood and normal-approximation methods of computing confidence intervals for model parameters and other quantities of interest. Explain the appropriate use of the density approximation for observations reported as exact failures. 7-2 Example: Between α-particle Emissions of Americium-241 (Berkson 1966) Berkson (1966) investigates the randomness of α-particle emissions of Americium-241, which has a half-life of about 458 years. Data: Interarrival times (units: 1/5000 seconds). n =10,220 observations. Data binned into intervals from 0 to 4000 time units. Interval sizes ranging from 25 to 100 units. Additional interval for observed times exceeding 4,000 time units. Smaller samples analyzed here to illustrate sample size effect. We start the analysis with n =200. Data for α-particle Emissions of Americium-241 Interarrival s Interval Endpoint All s Random Sample of s lower upper n = n = Histogram of the n = 200 Sample of α-particle Interarrival Data Exponential Probability Plot of the n = 200 Sample of α-particle Interarrival Data. The Plot also Shows Approximate 95% Simultaneous Nonparametric Confidence Bands. Frequency Probability
2 Parametric Likelihood Probability of the Data Using the model Pr(T t) = F(t;) for continuous T, the likelihood (probability) for a single observation in the interval (t i 1,t i ] is L i (;data i ) = Pr(t i 1 < T t i ) = F(t i ;) F(t i 1 ;). Can be generalized to allow for explanatory variables, multiple sources of variability, and other model features. and Likelihood for Interval Data Data: α-particle emissions of americium-241 The exponential distribution is ( F(t;) = 1 exp t ), t > 0. = E(T), the mean time between arrivals. The total likelihood is the joint probability of the data. Assuming n independent observations n L() = L(;DATA) = C L i (;data i ). i=1 Want to estimate and g(). We will find to make L() large. 7-7 The interval-data likelihood has the form n 8 [ L() = L i () = F(tj ;) F(t j 1 ;) ] d j i=1 j=1 8 [ ( = exp t ) ( j 1 exp t )] dj j j=1 where d j is the number of interarrival times in the jth interval (i.e., times between t j 1 and t j ). 7-8 R() = L()/L( ) for the n = 200 α-particle Interarrival Data. Vertical Lines Give an Approximate 95% Likelihood-Based Confidence Interval for Exponential Probability Plot for the n = 200 Sample of α-particle Interarrival Data. The Plot Also Shows Parametric Exponential ML Estimate and 95% Confidence Intervals for F(t). <- estimate of mean using all n=10220 times n=200 -> Probability ML Fit 95% Pointwise Confidence Intervals Example. α-particle Pseudo Data Constructed with Constant Proportion within Each Bin R() = L()/L( ) for the n = 20, 200, and 2000 Pseudo Data. Vertical Lines Give Corresponding Approximate 95% Likelihood-Based Confidence Intervals Interarrival s Interval Endpoint Samples of s lower upper n=20000 n=2000 n=200 n= <- estimate of mean using all n=20000 times n=20 -> n=200 -> <- n=
3 Example. α-particle Random Samples Interarrival s Interval Endpoint All s Random Samples of s lower upper n = n = 2000 n = 200 n=20 R() = L()/L( ) for the n = 20, 200, and 2000 Samples from the α-particle Interarrival Data. Vertical Lines Give Corresponding Approximate 95% Likelihood-Based Confidence Intervals. estimate of mean using all n=10220 times -> n=2000 n=20 n= Likelihood as a Tool for Modeling/Inference What can we do with the (log) likelihood? n L() = log[l()] = L i (). i=1 Likelihood as a Tool for Modeling/Inference (Continued) Regions of high likelihood are credible; regions of low likelihood are not credible (suggests confidence regions for parameters). Study the surface. Maximize with respect to (ML point estimates). Look at curvature at maximum (gives estimate of Fisher information and asymptotic variance). Observe effect of perturbations in data and model on likelihood (sensitivity, influence analysis) If the length of is > 1 or 2 and interest centers on subset of (need to get rid of nuisance parameters), look at profiles (suggests confidence regions/intervals for parameter subsets). Calibrate confidence regions/intervals with χ 2 or simulation (or parametric bootstrap). Use reparameterization to study functions of for Simulated Exponential ( = 5) Samples of Size n = 3 for Simulated Exponential ( = 5) Samples of Size n = 1000 Profile Likelihood Profile Likelihood theta theta
4 Large-Sample Approximate Theory for Likelihood Ratios for a Scalar Parameter Relative likelihood for is R() = L() L( ). If evaluated at the true, then, asymptotically, 2 log[r()] follows, a chisquare distribution with 1 degree of freedom. An approximate 100(1 α)% likelihood-based confidence region for is the set of all values of such that Normal-Approximation Confidence Intervals for A 100(1 α)% normal-approximation (or Wald) confidence interval for is [, ] = ±z (1 α/2) ŝe. where ŝe = [ d 2 L()/d 2] 1 is evaluated at. Based on = NOR(0,1) Z ŝe 2log[R()] < χ 2 (1 α;1) or, equivalently, the set defined by R() > exp [ χ 2 (1 α;1) /2]. General theory in the Appendix. From the definition of NOR(0, 1) quantiles Pr [ ] z (α/2) < z Z (1 α/2) 1 α implies that Pr [ z (1 α/2) < ŝe +z (1 α/2) ŝe ] 1 α Normal-Approximation Confidence Intervals for (continued) A 100(1 α)% normal-approximation (or Wald) confidence interval for is [, ] = [ /w, w] where w = exp[z (1 α/2) ŝe / ]. This follows after transforming (by exponentiation) the confidence interval [log(), log()] = log( )±z (1 α/2) ŝe log( ) which is based on Z log( ) = log( ) log() ŝe log( ) NOR(0,1) Because log( ) is unrestricted in sign, generally Z log( ) is Comparisons for α-particle Data All s Sample of s n =10,220 n = 200 n=20 ML Estimate Standard Error ŝe % Confidence Intervals for Based on Likelihood [585, 608] [498, 662] [289, 713] Z log( ) NOR(0,1) [585, 608] [496, 660] [281, 690] NOR(0,1) [585, 608] [491, 654] [242, 638] Z ML Estimate λ Standard Error ŝe λ % Confidence Intervals for λ 10 5 Based on Likelihood [164, 171] [151, 201] [140, 346] Z log( λ) NOR(0,1) [164, 171] [152, 202] [145, 356] NOR(0,1) [164, 171] [149, 200] [125, 329] Z λ closer to an NOR(0,1) distribution than is Z Density Approximation for Exact Observations Confidence Intervals for Functions of For one-parameter distributions, confidence intervals for can be translated directly into confidence intervals for monotone functions of. The arrival rate λ = 1/ is a decreasing function of. [λ, λ] = [1/, 1/ ] = [.00151,.00201]. F(t;) is a decreasing function of [F (t e), F(t e)] = [F(t e; ), F(t e; )]. If t i 1 = t i i, i > 0, and the correct likelihood F(t i ;) F(t i 1 ;) = F(t i ;) F(t i i ;) can be approximated with the density f(t) as ti [F(t i ;) F(t i i ;)] = f(t)dt f(t i;) i (t i i ) then the density approximation for exact observations may be appropriate. L i (;data i ) = f(t i ;) For most common models, the density approximation is adequate for small i. There are, however, situations where the approximation breaks down as i
5 ML Estimates for the Mean Based on the Density Approximation With r exact failures and n r right-censored observations the ML estimate of is = TTT ni=1 t i = r r TTT = n i=1 t i, total time in test, is the sum of the failure times plus the censoring time of the units that are censored. Confidence Interval for the Mean Life of a New Insulating Material A life test for a new insulating material used 25 specimens which were tested simultaneously at a high voltage of 30 kv. The test was run until 15 of the specimens failed. The 15 failure times (hours) were recorded as: Using the observed curvature in the likelihood: [ ] 1 = ŝe d2 L() 2 d 2 = r = r. If the data are complete or failure censored, 2TTT/ χ 2 2r. Then an exact 100(1 α)% confidence interval for is [, ] = 2(TTT) 2(TTT) χ 2, χ (1 α/2;2r) 2. (α/2;2r) , 3.16, 10.38, 10.75, 12.53, 16.74, 22.54, 25.01, 33.02, 33.93, 36.17, 39.06, 44.56, 46.65, Then TTT = = 958hours. The ML estimate of and a 95% confidence interval are: = 958/15 = hours [ ], = 2(958) χ 2, 2(958) χ (.975;30) 2 = (.025;30) = [48, ]. [ , ] Exponential Analysis With Zero Failures ML estimate for the Exponential distribution mean cannot be computed unless the available data contains one or more failures. For a sample of n units with running times t 1,...,t n and an assumed exponential distribution, a conservative 100(1 α)% lower confidence bound for is = 2(TTT) χ 2 = 2(TTT) 2log(α) = TTT log(α). (1 α;2) The lower bound can be translated into an lower confidence bound for functions like t p for specified p or a upper confidence bound for F(t e) for a specified t e. This bound is based on the fact that under the exponential failure-time distribution, with immediate replacement of failed units, the number of failures observed in a life test with a fixed total time on test has a Poisson distribution Analysis of the Diesel Generator Fan Data (Assuming Removal After 200 Hours of Service) Here we do the analysis of the fan data after 200 hours of testing when all the fans were still running. Thus TTT =14,000 hours. A conservative 95% lower confidence bound on is = 2(TTT) χ 2 = = (.95;2) Using the entire data set, = 28,701 and a likelihoodbased approximate 95% lower confidence bound is = 18,485 hours. A conservative 95% upper confidence bound on F(10000; ) is F(10000) = F(10000; ) = 1 exp( 10000/4674) =.882. This shows how little information comes from a short test with zero or few failures Other Topics in Chapter 7 Inferences when there are no failures. 7-29
Chapter 9. Bootstrap Confidence Intervals. William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University
Chapter 9 Bootstrap Confidence Intervals William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University Copyright 1998-2008 W. Q. Meeker and L. A. Escobar. Based on the authors
More informationChapter 17. Failure-Time Regression Analysis. William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University
Chapter 17 Failure-Time Regression Analysis William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University Copyright 1998-2008 W. Q. Meeker and L. A. Escobar. Based on the authors
More informationUnit 10: Planning Life Tests
Unit 10: Planning Life Tests Ramón V. León Notes largely based on Statistical Methods for Reliability Data by W.Q. Meeker and L. A. Escobar, Wiley, 1998 and on their class notes. 11/2/2004 Unit 10 - Stat
More informationThe Relationship Between Confidence Intervals for Failure Probabilities and Life Time Quantiles
Statistics Preprints Statistics 2008 The Relationship Between Confidence Intervals for Failure Probabilities and Life Time Quantiles Yili Hong Iowa State University, yili_hong@hotmail.com William Q. Meeker
More informationChapter 15. System Reliability Concepts and Methods. William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University
Chapter 15 System Reliability Concepts and Methods William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University Copyright 1998-2008 W. Q. Meeker and L. A. Escobar. Based on
More informationStatistical Prediction Based on Censored Life Data. Luis A. Escobar Department of Experimental Statistics Louisiana State University.
Statistical Prediction Based on Censored Life Data Overview Luis A. Escobar Department of Experimental Statistics Louisiana State University and William Q. Meeker Department of Statistics Iowa State University
More informationSample Size and Number of Failure Requirements for Demonstration Tests with Log-Location-Scale Distributions and Type II Censoring
Statistics Preprints Statistics 3-2-2002 Sample Size and Number of Failure Requirements for Demonstration Tests with Log-Location-Scale Distributions and Type II Censoring Scott W. McKane 3M Pharmaceuticals
More informationSTAT 6350 Analysis of Lifetime Data. Failure-time Regression Analysis
STAT 6350 Analysis of Lifetime Data Failure-time Regression Analysis Explanatory Variables for Failure Times Usually explanatory variables explain/predict why some units fail quickly and some units survive
More informationCOPYRIGHTED MATERIAL CONTENTS. Preface Preface to the First Edition
Preface Preface to the First Edition xi xiii 1 Basic Probability Theory 1 1.1 Introduction 1 1.2 Sample Spaces and Events 3 1.3 The Axioms of Probability 7 1.4 Finite Sample Spaces and Combinatorics 15
More informationData: Singly right censored observations from a temperatureaccelerated
Chapter 19 Analyzing Accelerated Life Test Data William Q Meeker and Luis A Escobar Iowa State University and Louisiana State University Copyright 1998-2008 W Q Meeker and L A Escobar Based on the authors
More informationSTATISTICAL INFERENCE IN ACCELERATED LIFE TESTING WITH GEOMETRIC PROCESS MODEL. A Thesis. Presented to the. Faculty of. San Diego State University
STATISTICAL INFERENCE IN ACCELERATED LIFE TESTING WITH GEOMETRIC PROCESS MODEL A Thesis Presented to the Faculty of San Diego State University In Partial Fulfillment of the Requirements for the Degree
More informationACCELERATED DESTRUCTIVE DEGRADATION TEST PLANNING. Presented by Luis A. Escobar Experimental Statistics LSU, Baton Rouge LA 70803
ACCELERATED DESTRUCTIVE DEGRADATION TEST PLANNING Presented by Luis A. Escobar Experimental Statistics LSU, Baton Rouge LA 70803 This is jointly work with Ying Shi and William Q. Meeker both from Iowa
More informationBayesian Life Test Planning for the Weibull Distribution with Given Shape Parameter
Statistics Preprints Statistics 10-8-2002 Bayesian Life Test Planning for the Weibull Distribution with Given Shape Parameter Yao Zhang Iowa State University William Q. Meeker Iowa State University, wqmeeker@iastate.edu
More informationStatistical Inference on Constant Stress Accelerated Life Tests Under Generalized Gamma Lifetime Distributions
Int. Statistical Inst.: Proc. 58th World Statistical Congress, 2011, Dublin (Session CPS040) p.4828 Statistical Inference on Constant Stress Accelerated Life Tests Under Generalized Gamma Lifetime Distributions
More informationNotes largely based on Statistical Methods for Reliability Data by W.Q. Meeker and L. A. Escobar, Wiley, 1998 and on their class notes.
Unit 2: Models, Censoring, and Likelihood for Failure-Time Data Notes largely based on Statistical Methods for Reliability Data by W.Q. Meeker and L. A. Escobar, Wiley, 1998 and on their class notes. Ramón
More informationMISCELLANEOUS TOPICS RELATED TO LIKELIHOOD. Copyright c 2012 (Iowa State University) Statistics / 30
MISCELLANEOUS TOPICS RELATED TO LIKELIHOOD Copyright c 2012 (Iowa State University) Statistics 511 1 / 30 INFORMATION CRITERIA Akaike s Information criterion is given by AIC = 2l(ˆθ) + 2k, where l(ˆθ)
More informationPractice Problems Section Problems
Practice Problems Section 4-4-3 4-4 4-5 4-6 4-7 4-8 4-10 Supplemental Problems 4-1 to 4-9 4-13, 14, 15, 17, 19, 0 4-3, 34, 36, 38 4-47, 49, 5, 54, 55 4-59, 60, 63 4-66, 68, 69, 70, 74 4-79, 81, 84 4-85,
More informationA Tool for Evaluating Time-Varying-Stress Accelerated Life Test Plans with Log-Location- Scale Distributions
Statistics Preprints Statistics 6-2010 A Tool for Evaluating Time-Varying-Stress Accelerated Life Test Plans with Log-Location- Scale Distributions Yili Hong Virginia Tech Haiming Ma Iowa State University,
More informationStatistics - Lecture One. Outline. Charlotte Wickham 1. Basic ideas about estimation
Statistics - Lecture One Charlotte Wickham wickham@stat.berkeley.edu http://www.stat.berkeley.edu/~wickham/ Outline 1. Basic ideas about estimation 2. Method of Moments 3. Maximum Likelihood 4. Confidence
More informationAccelerated Destructive Degradation Tests: Data, Models, and Analysis
Statistics Preprints Statistics 03 Accelerated Destructive Degradation Tests: Data, Models, and Analysis Luis A. Escobar Louisiana State University William Q. Meeker Iowa State University, wqmeeker@iastate.edu
More informationAccelerated Destructive Degradation Test Planning
Accelerated Destructive Degradation Test Planning Ying Shi Dept. of Statistics Iowa State University Ames, IA 50011 yshi@iastate.edu Luis A. Escobar Dept. of Experimental Statistics Louisiana State University
More informationReliability prediction based on complicated data and dynamic data
Graduate Theses and Dissertations Graduate College 2009 Reliability prediction based on complicated data and dynamic data Yili Hong Iowa State University Follow this and additional works at: http://lib.dr.iastate.edu/etd
More informationMaximum-Likelihood Estimation: Basic Ideas
Sociology 740 John Fox Lecture Notes Maximum-Likelihood Estimation: Basic Ideas Copyright 2014 by John Fox Maximum-Likelihood Estimation: Basic Ideas 1 I The method of maximum likelihood provides estimators
More informationSimultaneous Prediction Intervals for the (Log)- Location-Scale Family of Distributions
Statistics Preprints Statistics 10-2014 Simultaneous Prediction Intervals for the (Log)- Location-Scale Family of Distributions Yimeng Xie Virginia Tech Yili Hong Virginia Tech Luis A. Escobar Louisiana
More informationWarranty Prediction Based on Auxiliary Use-rate Information
Statistics Preprints Statistics 2009 Warranty Prediction Based on Auxiliary Use-rate Information Yili Hong Virginia Polytechnic Institute and State University William Q. Meeker Iowa State University, wqmeeker@iastate.edu
More informationAccelerated Testing Obtaining Reliability Information Quickly
Accelerated Testing Background Accelerated Testing Obtaining Reliability Information Quickly William Q. Meeker Department of Statistics and Center for Nondestructive Evaluation Iowa State University Ames,
More informationSTAT 6350 Analysis of Lifetime Data. Probability Plotting
STAT 6350 Analysis of Lifetime Data Probability Plotting Purpose of Probability Plots Probability plots are an important tool for analyzing data and have been particular popular in the analysis of life
More informationA Simulation Study on Confidence Interval Procedures of Some Mean Cumulative Function Estimators
Statistics Preprints Statistics -00 A Simulation Study on Confidence Interval Procedures of Some Mean Cumulative Function Estimators Jianying Zuo Iowa State University, jiyizu@iastate.edu William Q. Meeker
More informationStatistical Prediction Based on Censored Life Data
Editor s Note: Results following from the research reported in this article also appear in Chapter 12 of Meeker, W. Q., and Escobar, L. A. (1998), Statistical Methods for Reliability Data, New York: Wiley.
More informationChapter 18. Accelerated Test Models. William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University
Chapter 18 Accelerated Test Models William Q. Meeker and Luis A. Escobar Iowa State University and Louisiana State University Copyright 1998-2008 W. Q. Meeker and L. A. Escobar. Based on the authors text
More informationEmpirical Power of Four Statistical Tests in One Way Layout
International Mathematical Forum, Vol. 9, 2014, no. 28, 1347-1356 HIKARI Ltd, www.m-hikari.com http://dx.doi.org/10.12988/imf.2014.47128 Empirical Power of Four Statistical Tests in One Way Layout Lorenzo
More informationA Statistical Journey through Historic Haverford
A Statistical Journey through Historic Haverford Arthur Berg University of California, San Diego Arthur Berg A Statistical Journey through Historic Haverford 2/ 18 The Dataset Histograms Oldest? Arthur
More informationThe exponential distribution and the Poisson process
The exponential distribution and the Poisson process 1-1 Exponential Distribution: Basic Facts PDF f(t) = { λe λt, t 0 0, t < 0 CDF Pr{T t) = 0 t λe λu du = 1 e λt (t 0) Mean E[T] = 1 λ Variance Var[T]
More informationCox s proportional hazards model and Cox s partial likelihood
Cox s proportional hazards model and Cox s partial likelihood Rasmus Waagepetersen October 12, 2018 1 / 27 Non-parametric vs. parametric Suppose we want to estimate unknown function, e.g. survival function.
More informationFULL LIKELIHOOD INFERENCES IN THE COX MODEL
October 20, 2007 FULL LIKELIHOOD INFERENCES IN THE COX MODEL BY JIAN-JIAN REN 1 AND MAI ZHOU 2 University of Central Florida and University of Kentucky Abstract We use the empirical likelihood approach
More informationTesting Hypothesis. Maura Mezzetti. Department of Economics and Finance Università Tor Vergata
Maura Department of Economics and Finance Università Tor Vergata Hypothesis Testing Outline It is a mistake to confound strangeness with mystery Sherlock Holmes A Study in Scarlet Outline 1 The Power Function
More informationUnderstanding and Addressing the Unbounded Likelihood Problem
Statistics Preprints Statistics 9-2013 Understanding and Addressing the Unbounded Likelihood Problem Shiyao Liu Iowa State University Huaiqing Wu Iowa State University William Q. Meeker Iowa State University,
More informationStat 5101 Lecture Notes
Stat 5101 Lecture Notes Charles J. Geyer Copyright 1998, 1999, 2000, 2001 by Charles J. Geyer May 7, 2001 ii Stat 5101 (Geyer) Course Notes Contents 1 Random Variables and Change of Variables 1 1.1 Random
More informationQuantile POD for Hit-Miss Data
Quantile POD for Hit-Miss Data Yew-Meng Koh a and William Q. Meeker a a Center for Nondestructive Evaluation, Department of Statistics, Iowa State niversity, Ames, Iowa 50010 Abstract. Probability of detection
More informationAnalysis of Time-to-Event Data: Chapter 4 - Parametric regression models
Analysis of Time-to-Event Data: Chapter 4 - Parametric regression models Steffen Unkel Department of Medical Statistics University Medical Center Göttingen, Germany Winter term 2018/19 1/25 Right censored
More informationST495: Survival Analysis: Hypothesis testing and confidence intervals
ST495: Survival Analysis: Hypothesis testing and confidence intervals Eric B. Laber Department of Statistics, North Carolina State University April 3, 2014 I remember that one fateful day when Coach took
More informationInterval Estimation for Parameters of a Bivariate Time Varying Covariate Model
Pertanika J. Sci. & Technol. 17 (2): 313 323 (2009) ISSN: 0128-7680 Universiti Putra Malaysia Press Interval Estimation for Parameters of a Bivariate Time Varying Covariate Model Jayanthi Arasan Department
More informationUnit 20: Planning Accelerated Life Tests
Unit 20: Planning Accelerated Life Tests Ramón V. León Notes largely based on Statistical Methods for Reliability Data by W.Q. Meeker and L. A. Escobar, Wiley, 1998 and on their class notes. 11/13/2004
More informationBayesian Methods for Accelerated Destructive Degradation Test Planning
Statistics Preprints Statistics 11-2010 Bayesian Methods for Accelerated Destructive Degradation Test Planning Ying Shi Iowa State University William Q. Meeker Iowa State University, wqmeeker@iastate.edu
More informationStep-Stress Models and Associated Inference
Department of Mathematics & Statistics Indian Institute of Technology Kanpur August 19, 2014 Outline Accelerated Life Test 1 Accelerated Life Test 2 3 4 5 6 7 Outline Accelerated Life Test 1 Accelerated
More informationSemiparametric Regression
Semiparametric Regression Patrick Breheny October 22 Patrick Breheny Survival Data Analysis (BIOS 7210) 1/23 Introduction Over the past few weeks, we ve introduced a variety of regression models under
More informationOPTIMUM DESIGN ON STEP-STRESS LIFE TESTING
Libraries Conference on Applied Statistics in Agriculture 1998-10th Annual Conference Proceedings OPTIMUM DESIGN ON STEP-STRESS LIFE TESTING C. Xiong Follow this and additional works at: http://newprairiepress.org/agstatconference
More informationEXAMINATIONS OF THE ROYAL STATISTICAL SOCIETY
EXAMINATIONS OF THE ROYAL STATISTICAL SOCIETY GRADUATE DIPLOMA, 00 MODULE : Statistical Inference Time Allowed: Three Hours Candidates should answer FIVE questions. All questions carry equal marks. The
More informationUsing Accelerated Life Tests Results to Predict Product Field Reliability
Statistics Preprints Statistics 6-2008 Using Accelerated Life Tests Results to Predict Product Field Reliability William Q. Meeker Iowa State University, wqmeeker@iastate.edu Luis A. Escobar Louisiana
More informationBayesian Life Test Planning for the Log-Location- Scale Family of Distributions
Statistics Preprints Statistics 3-14 Bayesian Life Test Planning for the Log-Location- Scale Family of Distributions Yili Hong Virginia Tech Caleb King Virginia Tech Yao Zhang Pfizer Global Research and
More informationOptimum Test Plan for 3-Step, Step-Stress Accelerated Life Tests
International Journal of Performability Engineering, Vol., No., January 24, pp.3-4. RAMS Consultants Printed in India Optimum Test Plan for 3-Step, Step-Stress Accelerated Life Tests N. CHANDRA *, MASHROOR
More informationMAS3301 / MAS8311 Biostatistics Part II: Survival
MAS330 / MAS83 Biostatistics Part II: Survival M. Farrow School of Mathematics and Statistics Newcastle University Semester 2, 2009-0 8 Parametric models 8. Introduction In the last few sections (the KM
More informationOverview of Extreme Value Theory. Dr. Sawsan Hilal space
Overview of Extreme Value Theory Dr. Sawsan Hilal space Maths Department - University of Bahrain space November 2010 Outline Part-1: Univariate Extremes Motivation Threshold Exceedances Part-2: Bivariate
More informationSTT 843 Key to Homework 1 Spring 2018
STT 843 Key to Homework Spring 208 Due date: Feb 4, 208 42 (a Because σ = 2, σ 22 = and ρ 2 = 05, we have σ 2 = ρ 2 σ σ22 = 2/2 Then, the mean and covariance of the bivariate normal is µ = ( 0 2 and Σ
More informationEstimating a parametric lifetime distribution from superimposed renewal process data
Graduate Theses and Dissertations Iowa State University Capstones, Theses and Dissertations 2013 Estimating a parametric lifetime distribution from superimposed renewal process data Ye Tian Iowa State
More informationA hidden semi-markov model for the occurrences of water pipe bursts
A hidden semi-markov model for the occurrences of water pipe bursts T. Economou 1, T.C. Bailey 1 and Z. Kapelan 1 1 School of Engineering, Computer Science and Mathematics, University of Exeter, Harrison
More informationExamination paper for TMA4275 Lifetime Analysis
Department of Mathematical Sciences Examination paper for TMA4275 Lifetime Analysis Academic contact during examination: Ioannis Vardaxis Phone: 95 36 00 26 Examination date: Saturday May 30 2015 Examination
More informationAnalysis of Type-II Progressively Hybrid Censored Data
Analysis of Type-II Progressively Hybrid Censored Data Debasis Kundu & Avijit Joarder Abstract The mixture of Type-I and Type-II censoring schemes, called the hybrid censoring scheme is quite common in
More informationSTAT331. Cox s Proportional Hazards Model
STAT331 Cox s Proportional Hazards Model In this unit we introduce Cox s proportional hazards (Cox s PH) model, give a heuristic development of the partial likelihood function, and discuss adaptations
More informationInference on reliability in two-parameter exponential stress strength model
Metrika DOI 10.1007/s00184-006-0074-7 Inference on reliability in two-parameter exponential stress strength model K. Krishnamoorthy Shubhabrata Mukherjee Huizhen Guo Received: 19 January 2005 Springer-Verlag
More information3 Joint Distributions 71
2.2.3 The Normal Distribution 54 2.2.4 The Beta Density 58 2.3 Functions of a Random Variable 58 2.4 Concluding Remarks 64 2.5 Problems 64 3 Joint Distributions 71 3.1 Introduction 71 3.2 Discrete Random
More informationMaximum Likelihood (ML) Estimation
Econometrics 2 Fall 2004 Maximum Likelihood (ML) Estimation Heino Bohn Nielsen 1of32 Outline of the Lecture (1) Introduction. (2) ML estimation defined. (3) ExampleI:Binomialtrials. (4) Example II: Linear
More informationSubject CS1 Actuarial Statistics 1 Core Principles
Institute of Actuaries of India Subject CS1 Actuarial Statistics 1 Core Principles For 2019 Examinations Aim The aim of the Actuarial Statistics 1 subject is to provide a grounding in mathematical and
More informationChapter 2. Models, Censoring, and Likelihood for Failure-Time Data
Chaper 2 Models, Censoring, and Likelihood for Failure-Time Daa William Q. Meeker and Luis A. Escobar Iowa Sae Universiy and Louisiana Sae Universiy Copyrigh 1998-2008 W. Q. Meeker and L. A. Escobar. Based
More informationComparisons of Approximate Confidence Interval Procedures for Type I Censored Data
Statistics Preprints Statistics 6-6-999 Comparisons of Approximate Confidence Interval Procedures for Type I Censored Data Shuen-Lin Jeng Ming-Chuan University William Q. Meeker Iowa State University,
More informationChapter 6. Estimation of Confidence Intervals for Nodal Maximum Power Consumption per Customer
Chapter 6 Estimation of Confidence Intervals for Nodal Maximum Power Consumption per Customer The aim of this chapter is to calculate confidence intervals for the maximum power consumption per customer
More informationWeibull Reliability Analysis
Weibull Reliability Analysis = http://www.rt.cs.boeing.com/mea/stat/scholz/ http://www.rt.cs.boeing.com/mea/stat/reliability.html http://www.rt.cs.boeing.com/mea/stat/scholz/weibull.html Fritz Scholz (425-865-3623,
More informationTesting Statistical Hypotheses
E.L. Lehmann Joseph P. Romano Testing Statistical Hypotheses Third Edition 4y Springer Preface vii I Small-Sample Theory 1 1 The General Decision Problem 3 1.1 Statistical Inference and Statistical Decisions
More informationApproximation of Survival Function by Taylor Series for General Partly Interval Censored Data
Malaysian Journal of Mathematical Sciences 11(3): 33 315 (217) MALAYSIAN JOURNAL OF MATHEMATICAL SCIENCES Journal homepage: http://einspem.upm.edu.my/journal Approximation of Survival Function by Taylor
More informationGeneralized Linear Models
York SPIDA John Fox Notes Generalized Linear Models Copyright 2010 by John Fox Generalized Linear Models 1 1. Topics I The structure of generalized linear models I Poisson and other generalized linear
More informationBayesian Inference. Chapter 2: Conjugate models
Bayesian Inference Chapter 2: Conjugate models Conchi Ausín and Mike Wiper Department of Statistics Universidad Carlos III de Madrid Master in Business Administration and Quantitative Methods Master in
More informationβ j = coefficient of x j in the model; β = ( β1, β2,
Regression Modeling of Survival Time Data Why regression models? Groups similar except for the treatment under study use the nonparametric methods discussed earlier. Groups differ in variables (covariates)
More informationWeibull Reliability Analysis
Weibull Reliability Analysis = http://www.rt.cs.boeing.com/mea/stat/reliability.html Fritz Scholz (425-865-3623, 7L-22) Boeing Phantom Works Mathematics &Computing Technology Weibull Reliability Analysis
More informationInterval Estimation III: Fisher's Information & Bootstrapping
Interval Estimation III: Fisher's Information & Bootstrapping Frequentist Confidence Interval Will consider four approaches to estimating confidence interval Standard Error (+/- 1.96 se) Likelihood Profile
More informationNew Developments in Econometrics Lecture 16: Quantile Estimation
New Developments in Econometrics Lecture 16: Quantile Estimation Jeff Wooldridge Cemmap Lectures, UCL, June 2009 1. Review of Means, Medians, and Quantiles 2. Some Useful Asymptotic Results 3. Quantile
More informationLifetime prediction and confidence bounds in accelerated degradation testing for lognormal response distributions with an Arrhenius rate relationship
Scholars' Mine Doctoral Dissertations Student Research & Creative Works Spring 01 Lifetime prediction and confidence bounds in accelerated degradation testing for lognormal response distributions with
More informationDistribution Theory. Comparison Between Two Quantiles: The Normal and Exponential Cases
Communications in Statistics Simulation and Computation, 34: 43 5, 005 Copyright Taylor & Francis, Inc. ISSN: 0361-0918 print/153-4141 online DOI: 10.1081/SAC-00055639 Distribution Theory Comparison Between
More informationParametric Evaluation of Lifetime Data
IPN Progress Report 42-155 November 15, 2003 Parametric Evaluation of Lifetime Data J. Shell 1 The proposed large array of small antennas for the DSN requires very reliable systems. Reliability can be
More informationSTAT 135 Lab 3 Asymptotic MLE and the Method of Moments
STAT 135 Lab 3 Asymptotic MLE and the Method of Moments Rebecca Barter February 9, 2015 Maximum likelihood estimation (a reminder) Maximum likelihood estimation Suppose that we have a sample, X 1, X 2,...,
More informationMahdi karbasian* & Zoubi Ibrahim
International Journal of Industrial Engineering & Production Research (010) pp. 105-110 September 010, Volume 1, Number International Journal of Industrial Engineering & Production Research ISSN: 008-4889
More informationTwo-stage Adaptive Randomization for Delayed Response in Clinical Trials
Two-stage Adaptive Randomization for Delayed Response in Clinical Trials Guosheng Yin Department of Statistics and Actuarial Science The University of Hong Kong Joint work with J. Xu PSI and RSS Journal
More informationTheory and Methods of Statistical Inference. PART I Frequentist theory and methods
PhD School in Statistics cycle XXVI, 2011 Theory and Methods of Statistical Inference PART I Frequentist theory and methods (A. Salvan, N. Sartori, L. Pace) Syllabus Some prerequisites: Empirical distribution
More informationHazard Function, Failure Rate, and A Rule of Thumb for Calculating Empirical Hazard Function of Continuous-Time Failure Data
Hazard Function, Failure Rate, and A Rule of Thumb for Calculating Empirical Hazard Function of Continuous-Time Failure Data Feng-feng Li,2, Gang Xie,2, Yong Sun,2, Lin Ma,2 CRC for Infrastructure and
More informationPRINCIPLES OF STATISTICAL INFERENCE
Advanced Series on Statistical Science & Applied Probability PRINCIPLES OF STATISTICAL INFERENCE from a Neo-Fisherian Perspective Luigi Pace Department of Statistics University ofudine, Italy Alessandra
More informationChapter 1 Statistical Inference
Chapter 1 Statistical Inference causal inference To infer causality, you need a randomized experiment (or a huge observational study and lots of outside information). inference to populations Generalizations
More informationGeneralized additive modelling of hydrological sample extremes
Generalized additive modelling of hydrological sample extremes Valérie Chavez-Demoulin 1 Joint work with A.C. Davison (EPFL) and Marius Hofert (ETHZ) 1 Faculty of Business and Economics, University of
More informationTheory and Methods of Statistical Inference
PhD School in Statistics cycle XXIX, 2014 Theory and Methods of Statistical Inference Instructors: B. Liseo, L. Pace, A. Salvan (course coordinator), N. Sartori, A. Tancredi, L. Ventura Syllabus Some prerequisites:
More informationPart III. Hypothesis Testing. III.1. Log-rank Test for Right-censored Failure Time Data
1 Part III. Hypothesis Testing III.1. Log-rank Test for Right-censored Failure Time Data Consider a survival study consisting of n independent subjects from p different populations with survival functions
More informationEstimation of Quantiles
9 Estimation of Quantiles The notion of quantiles was introduced in Section 3.2: recall that a quantile x α for an r.v. X is a constant such that P(X x α )=1 α. (9.1) In this chapter we examine quantiles
More informationStatistics. Lecture 2 August 7, 2000 Frank Porter Caltech. The Fundamentals; Point Estimation. Maximum Likelihood, Least Squares and All That
Statistics Lecture 2 August 7, 2000 Frank Porter Caltech The plan for these lectures: The Fundamentals; Point Estimation Maximum Likelihood, Least Squares and All That What is a Confidence Interval? Interval
More informationPrediction of remaining life of power transformers based on left truncated and right censored lifetime data
Statistics Preprints Statistics 7-2008 Prediction of remaining life of power transformers based on left truncated and right censored lifetime data Yili Hong Iowa State University William Q. Meeker Iowa
More informationIntroduction to Statistics and Error Analysis II
Introduction to Statistics and Error Analysis II Physics116C, 4/14/06 D. Pellett References: Data Reduction and Error Analysis for the Physical Sciences by Bevington and Robinson Particle Data Group notes
More informationPrediction of remaining life of power transformers based on left truncated and right censored lifetime data
Center for Nondestructive Evaluation Publications Center for Nondestructive Evaluation 2009 Prediction of remaining life of power transformers based on left truncated and right censored lifetime data Yili
More informationMath 494: Mathematical Statistics
Math 494: Mathematical Statistics Instructor: Jimin Ding jmding@wustl.edu Department of Mathematics Washington University in St. Louis Class materials are available on course website (www.math.wustl.edu/
More informationHANDBOOK OF APPLICABLE MATHEMATICS
HANDBOOK OF APPLICABLE MATHEMATICS Chief Editor: Walter Ledermann Volume VI: Statistics PART A Edited by Emlyn Lloyd University of Lancaster A Wiley-Interscience Publication JOHN WILEY & SONS Chichester
More informationLecture 3. Truncation, length-bias and prevalence sampling
Lecture 3. Truncation, length-bias and prevalence sampling 3.1 Prevalent sampling Statistical techniques for truncated data have been integrated into survival analysis in last two decades. Truncation in
More informationExercise 5.4 Solution
Exercise 5.4 Solution Niels Richard Hansen University of Copenhagen May 7, 2010 1 5.4(a) > leukemia
More informationTheory and Methods of Statistical Inference. PART I Frequentist likelihood methods
PhD School in Statistics XXV cycle, 2010 Theory and Methods of Statistical Inference PART I Frequentist likelihood methods (A. Salvan, N. Sartori, L. Pace) Syllabus Some prerequisites: Empirical distribution
More informationST745: Survival Analysis: Nonparametric methods
ST745: Survival Analysis: Nonparametric methods Eric B. Laber Department of Statistics, North Carolina State University February 5, 2015 The KM estimator is used ubiquitously in medical studies to estimate
More informationCOMPETING RISKS WEIBULL MODEL: PARAMETER ESTIMATES AND THEIR ACCURACY
Annales Univ Sci Budapest, Sect Comp 45 2016) 45 55 COMPETING RISKS WEIBULL MODEL: PARAMETER ESTIMATES AND THEIR ACCURACY Ágnes M Kovács Budapest, Hungary) Howard M Taylor Newark, DE, USA) Communicated
More information