Browsing Research Report by Title
Now showing items 83-102 of 130
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Relative Efficiency of a Quantile Method for Estimating Parameters in Censored Two-Parameter Weibull Distributions
(University of Gothenburg, 2010-11-01)In simulation studies the computer time can be much reduced by using censoring. Here a simple method based on quantiles (Q method) is compared with the Maximum Likelihood (ML) method when estimating the parameters in ... -
Repeated measurement designs for models with self and mixed carryover effects
(University of Gothenburg, 1998-09-01)We study the problem of design and analysis of two-period repeated measurement (crossover or changeover) designs based on two or more treatments. In our model we allow the appearance of two types of carryovers (residuals) ... -
RESAMPLING PROCEDURES IN LINEAR MODELS
(University of Gothenburg, 1993-03-01)We will study here different resampling procedures for creating confidence sets in linear models. A special technique called abstract resampling makes it possible to use the true residuals and the true model for resampling. ... -
SATURATED DESIGNS FOR SECOND ORDER MODELS
(University of Gothenburg, 1994-09-01)Construction of saturated designs for different types of second order models are discussed. Also a comparison between two types of saturated designs for the full second order model is presented. -
Screening-related prevalence and incidence for non-recurrent diseases
(University of Gothenburg, 1997-02-01)Expressions for prevalence (P) and incidence (I) in open dynamic populations are derived. When screenings are performed every s:th year, P and I will be functions of s. It is shown how the true values of P and l, which ... -
Semiparametric estimation of outbreak regression
(2008-07-02)A regression may be constant for small values of the independent variable (for example time), but then a monotonic increase starts. Such an “outbreak” regression is of interest for example in the study of the outbreak of ... -
Semiparametric surveillance of outbreaks
(2008-07-02)The detection of a change from a constant level to a monotonically increasing (or decreasing) regression is of special interest for the detection of outbreaks of, for example, epidemics. A maximum likelihood ratio statistic ... -
SEPARATION OF SYSTEMATIC AND RANDOM ERRORS IN ORDINAL RATING SCALES
(University of Gothenburg, 1992-04-01)The aim of this paper is to introduce a new rank method which enables us to separate the inconsistency of repeated measurements into random and systematic differences and to quantify this lack of consistency in a few ... -
SEQUENTIAL ANALYSIS OF SIMPLE HYPOTHESES WHEN USING PLAY-THE-WINNER ALLOCATION
(University of Gothenburg, 1996-01-01)Play-the-winner allocations aim to place more subjects on the better treatment. The subjects enter the study sequentially. In this paper, a method for analyzing a dichotomous response, when using the randomized play-the-winner ... -
Sequential probability ratio tests when using randomized play-the-winner allocation
(University of Gothenburg, 1997-01-01)In many clinical experiments there is a conflict between ethical demands to provide the best possible medical care for the patients and the statisticians desire to obtain an efficient experiment. Play-the-winner allocations ... -
Similarities and differences between statistical surveillance and certain decision rules in finance
(2007-12-13)Financial trading rules have the aim of continuously evaluating available information in order to make timely decisions. This is also the aim of methods for statistical surveillance. Many results are available regarding ... -
Similarities and differences between statistical surveillance and certain decision rules in finance
(University of Gothenburg, 2003-04-01)this paper we consider prospective decision rules that aim at extracting early signals about what decision to make, e.g. sell an asset. The decision rules are based on prospective monitoring of a statistic in order to ... -
Simple conservative confidence intervals for comparing matched proportions
(University of Gothenburg, 2011-01-01)Unconditional confidence intervals (CIs) for the difference between marginal proportions in matched pairs data have essentially been based on improvements of Wald’s large-sample statistic. The latter are approximate and ... -
Some aspects of wavelet anal ysis in time series
(University of Gothenburg, 2000-04-01)The first paper describes an alternative approach for testing the existence of trend among time series. The test method has been constructed using wavelet analysis which have the ability to decompose a time series into low ... -
Some interaction models for clustered point patterns
(University of Gothenburg, 1998-08-01)We introduce a class of spatial point processes, interacting neighbour processes, where the density of the process can be written by means of local interactions between a point and subsets of its neighbourhood but where ... -
Some power aspects of methods for detecting different shifts in the mean
(University of Gothenburg, 1999-07-01)We study, by means of simulations, the performance of the Shewhart method, the Cusum method, the Shiryaev-Roberts method and the likelihood ratio method in the case when the true shift differs from the shift for which the ... -
Some principles for surveillance adopted for multivariate processes with a common change point
(University of Gothenburg, 1996-02-01)The surveillance of multivariate processes has received growing attention during the last decade. Several generalizations of well-known methods such as Shew hart , CUSUM and EWMA charts have been proposed. Many of these ... -
Some statistical aspects on methods for detection of turning points in business cycles
(University of Gothenburg, 2002-07-01)Statistical and practical aspects on methods for on-line turning point detection in business cycles are discussed. When a method is used on a real data set, there are a number of special data problems to be considered. ... -
Statistical issues in public health monitoring - A review and discussion
(University of Gothenburg, 2001-02-01)A review of methods, suggested in the literature, for sequential detection of changes in public health surveillance data is presented. Many authors have noticed the need for prospective methods and there has been an increased ... -
Statistical measures for evaluation of methods for syndromic surveillance
(2003-11-01)Introduction In syndromic surveillance there is a need for continual observation of one or more time series, with the goal of detecting an important change in the underlying process as soon as possible after it has ...