bluuebunny/crossref_metadata_2025_split huggingface dataset:
ASYMPTOTIC PROPERTIES OF RESTRICTED MAXIMUM LIKELIHOOD (REML) ESTIMATES FOR HIERARCHICAL MIXED LINEAR MODELS
Authors: RICHARDSON A.M. , WELSH A.H. 
Published: February 2008

SummaryThis paper explores the asymptotic distribution of the restricted maximum likelihood estimator of the variance components in a general mixed model. Restricting attention to hierarchical models, central limit theorems are obtained using elementary arguments with only mild conditions on the covariates in the fixed part of the model and without having to assume that the data are either normally or spherically symmetrically distributed. Further, the REML and maximum likelihood estimators are shown to be asymptotically equivalent in this general framework, and the asymptotic distribution of the weighted least squares estimator (based on the REML estimator) of the fixed effect parameters is derived.
SHOULD WE ESTIMATE THE PROBABILITY OF CORRECT SELECTION?
Authors: BOFINGER EVE 
Published: February 2008

SummaryVarious authors, given k location parameters, have considered lower confidence bounds on (standardized) dserences between the largest and each of the other k ‐ 1 parameters. They have then used these bounds to put lower confidence bounds on the probability of correct selection (PCS) in the same experiment (as was used for finding the lower bounds on differences). It is pointed out that this is an inappropriate inference procedure. Moreover, if the PCS refers to some later experiment it is shown that if a non‐trivial confidence bound is possible then it is already possible to conclude, with greater confidence, that correct selection has occurred in the first experiment. The short answer to the question in the title is therefore ‘No’, but this should be qualified in the case of a Bayesian analysis.
ASYMPTOTIC EXPANSIONS APPLIED TO F‐TEST CRITERIA
Authors: GOVINDARAJULU Z. , HOWARD H.C. 
Published: February 2008

SummaryUsing asymptotic expansions of the Kummer hypergeometric function, the sequential. F‐test criterion is evaluated asymptotically in terms of the sample size. The continuation region inequalities for the test are inverted and expressed in terms of known test criteria. A rapidly converging algorithm for carrying out the sequential procedure is provided. This makes the F‐test easier for the practitioner to use. Almost sure finite termination of the sequential. F‐test is asserted by appealing to the continuation inequalities and a heuristic asymptotic expansion of the test criterion. Average stopping times of the sequential procedure for a variety of population means and population number configurations are tabulated. The computer symbolic manipulation program MAPLE was used to derive some formulae.
A STOCHASTIC MODEL FOR TEAM GOLF COMPETITIONS WITH APPLICATIONS TO HANDICAPPING
Authors: Tallis G.M. 
Published: February 2008

SummaryThis paper examines the current handicapping systems for team golf competitions. Ambrose, foursomes, Canadian foursomes and Pinehurst events are analysed. Statistical models are built to capture the stochastic features of these events, and to allow new handicapping systems to be developed. Some substantial discrepancies between the new and the old systems are noted.
ON CONFIDENCE REGIONS OF EMBEDDED MODELS IN REGULAR PARAMETRIC FAMILIES (A GEOMETRIC APPROACH)
Authors: Wei Bo‐Cheng 
Published: February 2008

SummaryRegular parametric families are commonly encountered in statistical problems (e.g. Cox & Hinkley, 1974). In this paper, we propose a differential geometric framework for the embedded models in these families. Our framework may be regarded as an extension of that presented by Bates & Watts (1980) for nonlinear regression models. As an application, we use this geometric framework to derive three kinds of improved approximate confidence regions for the parameter and parameter subsets in terms of curvatures. The results obtained by Hamiltonet al.(1982) and Hamilton (1986) are extended to embedded models in regular parametric families.
PROBABILITY APPROXIMATIONS FOR DIVISIBLE DISCRETE DISTRIBUTIONS
Authors: Quine M.P. 
Published: February 2008

SummaryIf an integer‐valued random variable can be represented as a sum of independent random variables, then powerful tools exist to derive approximations to its distribution. We apply this idea to examples in some of which it is not clear how to give a physical interpretation to the independent sum‐mands. We consider bounds on the accuracy of single term approximations, Edgeworth expansions and saddlepoint approximations for both individual probabilities and cumulative probabilities.
LOCATION OF THE OPTIMAL SAMPLING POINT FOR THE QUALITY ASSESSMENT OF CONTINUOUS STREAMS
Authors: Barnett Neil S. , Gomm Ian S. , Armour Len 
Published: February 2008

SummaryThe paper makes an appraisal of the most appropriate sampling point for situations where a single sample must be used to estimate the mean flow of a continuous stream during a set time interval. Taking ‘optimal’ to mean the point at which the estimation error variance is minimised, optimal sampling locations are obtained for constant, linear and exponential flow rates when the process variogram is assumed linear or exponential. Numerical results illustrate the significance of failing to sample at the optimal point.
SMOOTH TESTS FOR THE BIVARIATE POISSON DISTRIBUTION
Authors: Rayner J.C.W. , Best D.J. 
Published: February 2008

SummaryA theorem of Rayner & Best (1989) is generalised to permit the construction of smooth tests of goodness of fit without requiring a set of orthonormal functions on the hypothesised distribution. This result is used to construct smooth tests for the bivariate Poisson distribution. The test due to Crockett (1979) is similar to a smooth test that assesses the variance structure under the bivariate Poisson model; the test due to Loukas & Kemp (1986) is related to a smooth test that seeks to detect a particular linear relationship between the variances and covariance under the bivariate Poisson model. Using focused smooth tests may be more informative than using previously suggested tests. The distribution of the Loukas & Kemp (1986) statistic is not well approximated by the x2distribution for larger correlations, and a revised statistic is suggested.
ROBUST VARIABLE SELECTION IN REGRESSION IN THE PRESENCE OF OUTLIERS AND LEVERAGE POINTS
Authors: Sommer Suzanne , Staudte Robert G. 
Published: February 2008

SummaryIn linear regression, outliers and leverage points often have large influence in the model selection process. Such cases are downweighted with Mallows‐type weights here, during estimation of submodel parameters by generalised M‐estimation. A robust version of Mallows's Cp (Ronchetti &. Staudte, 1994) is then used to select a variety of submodels which are as informative as the full model. The methodology is illustrated on a new dataset concerning the agglomeration of alumina in Bayer precipitation.
SOME PROPERTIES OF A FOLDOVER DESIGN
Authors: Diamond Neil T. 
Published: February 2008

SummaryThe foldover design of the 12‐run Plackett‐Burman design is shown to give a 24and 24‐1design in every set of four factors, and to be resolutionVin every set of five factors. In addition, the design allows the search and estimation of up to two non‐zero interactions.
THE OPTIMAL CRITICAL VALUE OF A PRE‐TEST FOR AN INEQUALITY RESTRICTION IN A MIS‐SPECIFIED REGRESSION MODEL
Authors: Wan Alan T.K. 
Published: February 2008

SummaryOptimal critical values are derived for a pre‐test of an inequality restriction in a model where relevant regressors are unwittingly omitted. The criterion adopted is either that of the minimum average relative risk, or that of the mini‐max regret. The latter approach yields an optimal critical value which is sensitive to the degree of model mis‐specification, while the former criterion always leads to the choice of the unrestricted estimator.
QUALITY ISSUES IN TELEPHONE SURVEYS: COVERAGE, NON‐RESPONSE and QUOTA SAMPLING
Authors: Steel David , Vella Joe , Harrington Peter 
Published: February 2008

SUMMARYThe quality of a telephone survey is affected by several factors: telephone coverage, non‐response, the methods used to select households and persons, and the quality of responses obtained from respondents. Data are provided which show that a large proportion of Australian households have telephone connections. However, telephone coverage is not uniform and some subgroups of the population have much lower connection rates. This paper reviews evidence of the effect of non‐response and the effectiveness of repeated call backs, and reports the results of a new study. The use of quota sampling to select respondents from randomly selected households is also examined. The results suggest that telephone surveys under‐represent older persons and the unemployed, and over‐represent middle‐aged persons. It is shown that while call backs can increase the response rate, the effect on the composition of the sample and resulting estimates is minimal. The main effects are due to refusals and variation in coverage rates.
CHANCE OF MISCLASSIFICATION IN THE CASE OF SEVERAL NORMAL POPULATIONS
Authors: Paek Pil S. , Kshirsagar AnantM. 
Published: February 2008

SUMMARYWhen a new observation is to be classified into one of several multivariate normal populations with different means and the same covariance matrix, by Rao's method of scoring, the chance of misclassification is expressed as a multiple integral. This paper gives a practical method of obtaining reasonable approximations to this integral by using tables prepared by Gibbons, Olkin & Sobel (1977) for a different task.
A NEW MEASURE OF ROTATABILITY OF RESPONSE SURFACE DESIGNS
Authors: Kshirsagar AnantM. , Chung‐inCheng Joanna 
Published: February 2008

SUMMARYThis paper proposes a new measure of rotatability of a response surface design. It is based on a comparison between the design moments of a given design and the design moments of a rotatable design closest to the given design in the least squares sense. This measure is easier to calculate than Khurľs measure. An alternative easier non‐geometrical way of deriving Khuri's measure is also presented. Both measures are calculated to illustrate some designs considered by Khuri.
MULTIPERIOD FORECASTING ANALYSIS OF A DYNAMIC MODEL FOR A SMALL SAMPLE
Authors: Hoque Asraul 
Published: February 2008

SummaryIn this paper we derive the formulae for the bias and mean squared forecast error (MSFE) of the least squares forecast several periods ahead in the context of a dynamic model. Since the expressions are in terms of integrals, we have also obtained the numerical value of the bias and MSFE for different values of parameters and different disturbance structures. The results confirm some earlier studies (based on the AR(1) model), for example Lahiri (1975) and Hoque et al. (1988).
COMPONENTS OF VARIANCE MODELS WITH TRANSFORMATIONS
Authors: Taylor Jeremy M.G. , Cumberland William G. , Meng Xiangyi 
Published: February 2008

SummaryPower transformations are a popular way to improve the agreement between the observations and the assumptions in a statistical model. In this paper it is assumed that the data, after appropriate power transformation Λ, satisfies a variance components model, with independent Gaussian components. The focus is on inference for quantities which have an interpretation regardless of the choice of Λ (Carroll & Ruppert, 1981) – in particular the intraclass correlation coefficient ρ, the predicted probability of a new observation being less than a specified value and the predicted quantile. It is shown that, in the case Λ= 0, the asymptotic variance of ρ is the same, whether or not one treats Δ as estimated or as known. This supports an empirical conjecture of Solomon (1985). For predicted probabilities and predicted quantiles the variance when A is estimated is shown to be only slightly greater than the variance assuming Δ is known, except in the tails of the distribution where there can be substantial difference between the two variances.
HITTING LINES and CIRCLES WITH DIFFUSION PROCESSES
Authors: Lefebvre Mario , Labib Richard 
Published: February 2008

SummaryFor (x(t),y(t)), a diffusion process starting from (x(0),y(0)) = (x,y), the problem of computing the moment generating function of the first passage time T(x, y) to a given subset D of IR2is considered. A particular case of the method of similarity solutions is used. The problems that can be solved explicitly are those for which D is either a straight line or a circle.
DISPERSION CONTROL FOR MULTIVARIATE PROCESSES
Authors: Tang Pak F. , Barnett Neil S. 
Published: February 2008

SummaryThis paper presents some techniques for monitoring and controlling the dispersion of multivariate normal processes based on subgroup data. The procedures involve use of independent statistics resulting from the decomposition of the covariance matrix. Those that do not depend on prior estimates of the process covariance matrix are particularly attractive to short‐run or low volume manufacturing environments.
ON THE GENERALIZED RAO‐RUBIN CONDITION and SOME VARIANTS
Authors: Sapatinas Theofanis 
Published: February 2008

SummaryThis paper gives a characterization of some members of the compound Poisson family of distributions based on the generalized Rao‐Rubin condition. By considering some variants of this condition and using power series arguments, characterizations of the Poisson distribution are also obtained.
INFLUENCE DIAGNOSTICS IN PROPER DISPERSION MODELS
Authors: Paula Gilberto A. 
Published: February 2008

SummaryThis paper discusses the application of influence diagnostic methods in univariate proper dispersion models. This class includes, in particular, continuous generalized linear models as well as other subclasses of continuous regression models. We emphasize the study of the local influence on the likelihood displacement and predictions from the models. Some of the diagnostics are illustrated by an example on directional data.
RANDOM THRESHOLD MODELS APPLIED TO INFLATED ZERO CLASS DATA
Authors: Saei Ayoub , McGilchrist C.A. 
Published: February 2008

summaryFor a random component threshold model, the threshold parameters are functions of a linear combination of fixed and random components. This paper describes estimation procedures in terms of composite link functions. The models give a good fit to the frequency of use of medical procedures in the different counties of Washington State, USA. Suitable models for studying change in county effects in successive years are developed.
ASSESSING ERROR RATE ESTIMATORS: THE LEAVE‐ONE‐OUT METHOD RECONSIDERED
Authors: Krzanowski W.J. , Hand D.J. 
Published: February 2008

summaryMany comparative studies of the estimators of error rates of supervised classification rules are based on inappropriate criteria. In particular, although they fix the Bayes error rate, their summary statistics aggregate a range of true error rates. This means that their conclusions about the performance of classification rules cannot be trusted. This paper discusses the general issues involved, and then focuses attention specifically on the leave‐one‐out estimator. The estimator is investigated in a simulation study, both in absolute terms and in comparison with a popular bootstrap estimator. An improvement to the leave‐one‐out estimator is suggested, but the bootstrap estimator appears to maintain superiority even when the criteria are adjusted.
EMPIRICAL LIKELIHOOD‐BASED KERNEL DENSITY ESTIMATION
Authors: Chen Song Xi 
Published: February 2008

summaryThis paper considers the estimation of a probability density function when extra distributional information is available (e.g. the mean of the distribution is known or the variance is a known function of the mean). The standard kernel method cannot exploit such extra information systematically as it uses an equal probability weight n‐1 at each data point. The paper suggests using empirical likelihood to choose the probability weights under constraints formulated from the extra distributional information. An empirical likelihood‐based kernel density estimator is given by replacing n‐1 by the empirical likelihood weights, and has these advantages: it makes systematic use of the extra information, it is able to reflect the extra characteristics of the density function, and its variance is smaller than that of the standard kernel density estimator.
CONDITIONING AND CONCENTRATION OF PRINCIPAL COMPONENTS
Authors: Jensen D.R. 
Published: February 2008

summaryThis paper uses various gauges to construct principal variables that satisfy criteria of maximal scatter. The solutions coincide with Hotelling's (1933) principal components in structured ensembles and mixtures, including heavy‐tailed distributions not having moments. Thus, normal‐theory tests are exact in level and power under nonstandard models allowing for correlated vector observations and for certain mixtures having neither moments nor unimodal marginals.
STEPWISE TESTS WHEN THE TEST STATISTICS ARE INDEPENDENT
Authors: Liu Wei 
Published: February 2008

summaryConsider the problem of simultaneously testing a nonhierarchical finite family of hypotheses based on independent test statistics. A general stepwise test is defined, of which the well known step‐down and step‐up tests are special cases. The step‐up test is shown to dominate the other stepwise tests, including the step‐down test, for situations of practical importance. When testing against two‐sided alternatives, it is pointed out that if the step‐up test is augmented to include directional decisions then the augmented step‐up test controls the type I and III familywise error jointly at the original level q. The definition of the adjusted p values for the step‐up test is justified. The results are illustrated by a numerical example.
Molecular biomarkers monitoring human skeletal muscle fibres and microvasculature following long‐term bed rest with and without countermeasures
Authors: Salanova M. , Schiffl G. , Püttmann B. , Schoser B. G. , Blottner D. 
Published: February 2008

AbstractThe cellular mechanisms of human skeletal muscle adaptation to disuse are largely unknown. The aim of this study was to determine the morphological and biochemical changes of the lower limb soleus and vastus lateralis muscles following 60 days of head‐down tilt bed rest in women with and without exercise countermeasure using molecular biomarkers monitoring functional cell compartments. Muscle biopsies were taken before (pre) and after bed rest (post) from a bed rest‐only and a bed rest exercise group (n = 8, each). NOS1 and NOS3/PECAM, markers of myofibre ‘activity’ and capillary density, and MuRF1 (E3 ubiquitin‐ligase), a marker of proteolysis, were documented by confocal immunofluorescence and immunoblot analyses. Morphometrical parameters (myofibre cross‐sectional area, type I/II distribution) were largely preserved in muscles from the exercise group with a robust trend for type II hypertrophy in vastus lateralis. In the bed rest‐only group, the relative NOS1 immunostaining intensity was decreased at type I and II myofibre membranes, while the bed rest plus exercise group compensated for this loss particularly in soleus. In the microvascular network, NOS3 expression and the capillary‐to‐fibre ratio were both increased in the exercise group. Elevated MuRF1 immunosignals found in subgroups of atrophic myofibres probably reflected accelerated proteolysis. Immunoblots revealed overexpression of the MuRF1 protein in the soleus of the bed rest‐only group (> 35% vs. pre). We conclude that exercise countermeasure during bed rest affected both NOS/NO signalling and proteolysis in female skeletal muscle. Maintenance of NO signalling mechanisms and normal protein turnover by exercise countermeasure may be crucial steps to attenuate human skeletal muscle atrophy and to maintain cell function following chronic disuse.
Climate‐ and resource‐driven long‐term changes in dormice populations negatively affect hole‐nesting songbirds
Authors: Adamík P. , Král M. 
Published: February 2008

AbstractGlobal climate change has been shown to cause variable shifts in phenology in a variety of animals and unexpected outcomes across food chains are to be found. Here we examined how rising annual spring temperatures affected the interactions between seed masting, cavity nesting birds and dormice using long‐term data from Eastern Czech Republic. We have shown that climate change was associated with unequal shifts in the phenology of two cavity‐breeding groups: dormice and birds. Rising spring temperatures have progressively advanced the termination of hibernation for the edible dormouse Glis glis, a common bird predator, leading to an increasing overlap in the use of nesting boxes between dormice and birds. In contrast, only the collared flycatcher Ficedula albicollis, of the four cavity‐nesting bird species, advanced its breeding dates in response to rising temperatures. At the same time, favourable weather conditions, coupled with good seed masting years, have been associated with a substantial rise in dormice numbers. Concurrent with the increasing dormice abundance, the number of bird nests destroyed significantly increased in three out of four bird species. We showed that while there was a significant change in the date that the dormice emerged from hibernation during the course of the study, it did not significantly contribute to predation levels when controlling for their abundance and timing of breeding in birds. We found that the increasing dormice abundance was the main factor causing high brood losses in birds, while the timing of breeding in birds had a variable effect between bird species. This study illustrates how changes in climate might affect organisms at various trophic levels with often unexpected outcomes. Limited evidence from other study organisms suggests that species most at risk are those at different trophic levels that do not shift at the same rate or in the same direction as their food resources, predators or competitors.
Variations in the echolocation calls of the European free‐tailed bat
Authors: Bayefsky‐Anand S. , Skowronski M. D. , Fenton M. B. , Korine C. , Holderied M. W. 
Published: February 2008

AbstractThe echolocation calls of Tadarida teniotis were studied in an outdoor flight enclosure (captive individuals) and in the wild using single microphones or an array of four microphones. Calls were characterized by measures of 10 call variables. Comparison of individual calls recorded on four microphones arrayed in a tetrahedron with 1 m between each microphone revealed that all calls were not equally detectable by all microphones but that there were no significant differences in call features obtained from calls recorded on all four microphones. A comparison of 47 calls recorded by all four microphones showed no significant differences in the features of the four recordings of each call. Analysis of calls of five individuals flying individually in an outdoor flight cage revealed significant individual differences in call features. In the field, T. teniotis used long, narrowband search‐phase calls, usually without harmonics. Analysis of 1876 search‐phase echolocation calls of T. teniotis recorded in the field in Israel and Greece in 2002, 2005 and 2006 showed significant year‐to‐year and site‐to‐site differences in some call features. When flying in the presence of conspecifics, T. teniotis changed their echolocation calls. We found a range of different buzzes in the wild, and based on their structure we attempted to classify them as feeding and social buzzes. The features of individual calls comprising buzzes differed significantly among buzzes, and yet there were no consistent differences between what we classified as feeding and social buzzes.