cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Fitting Generalized Linear Mixed Effects Models for Longitudinal Binary Data Using Different Correlation Structures
Creators: name: Cabral, M. Salomé
name: Gonçalves, M. Helena
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: The generalized linear mixed effects model (GLMM) approach is widely used to analyze longitudinal binary data when the goal of the study is a subject-specific interpretation because it allows missing values on the response, provided they are missing at random (MAR), and accounts the correlation among the repeated observations of the same subject by the inclusion of random effects in the linear predictor. However, in GLMM it is assumed that the observations of the same subject are independent conditional to the random effects and covariates which may be not true. To overcome this problem [9] extended this model using binary Markov chains as the basic stochastic mechanism. The aim of this paper is to give a statistical assessment of both approaches in terms of properties such as efficiency and coverage probability, as well as, to give some guidelines for the choice of the statistical approach to an applied researcher. Both procedures are described and a simulation study is carried out to compare their performance. An analysis of a longitudinal binary data set illustrates the performance of both procedures in a practical example. The R packages lme4 and bild are used.
description: REVSTAT-Statistical Journal, Vol. 16 No. 4 (2018): REVSTAT-Statistical Journal
Highly D-Efficient Weighing Designs for an Even Number of Objects
Creators: name: Ceranka, Bronisław
name: Graczyk, Małgorzata
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: In this paper we formulate how to add a = 1, 2, 3 runs to a near D-optimal weighing design to get a highly D-efficient weighing design when the number of objects p is even.
description: REVSTAT-Statistical Journal, Vol. 16 No. 4 (2018): REVSTAT-Statistical Journal
Parametric Tests of Perfect Judgment Ranking Based on Ordered Ranked Set Samples
Creators: name: Zamanzade, Ehsan
name: Vock, Michael
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: We develop parametric and location-scale free tests of perfect judgment ranking based on ordered ranked set samples. The tests are based on the differences between the elements of the ordered ranked set samples and those of the original ranked set samples. We compare our proposed tests with the best existing tests of perfect judgment ranking in the literature by using Monte Carlo simulation. Our simulation results show that the proposed tests behave favorably in comparison with their leading competitors, especially under the fraction of neighbor rankings model. In comparison to the nonparametric competitors, the proposed tests have the advantage of not needing randomization to attain a specific size.
description: REVSTAT-Statistical Journal, Vol. 16 No. 4 (2018): REVSTAT-Statistical Journal
Bayesian Robustness Modelling Using the Floor Distribution
Creators: name: A. A. Andrade, J.
name: Omey, Edward
name: M. Aquino, C. T.
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: In Bayesian analysis, the prior distribution and the likelihood can conflict, in the sense that they can carry diverse information about the parameter of interest. The most common form of conflict is the presence of outliers in the data. Usually, problems of conflicts are solved by assigning heavy-tailed distributions to that source of information which may be causing the conflict. However, the class of heavy-tailed distributions is not well defined, therefore there are many ways to define heavy tails. The class O-regularly varying distributions is rather unknown in Statistics, it basically embraces those distributions whose tails decay oscillating between two power functions. In this work we study a new distribution which has this property and, as a consequence, yields robust models for location and for scale parameter models separately. We provide explicit expressions for some relevant quantities concerning the distribution, such as the moments, distribution function, etc. Besides, we show how conflicts can be resolved using this distribution.
description: REVSTAT-Statistical Journal, Vol. 16 No. 4 (2018): REVSTAT-Statistical Journal
Parameter Estimation for the Log-Logistic Distribution Based on Order Statistics
Creators: name: Ahsanullah, Mohammad
name: Alzaatreh, Ayman
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: In this paper, we discuss the moments and product moments of the order statistics in a sample of size n drawn from the log-logistic distribution. We provide more compact forms for the mean, variance and covariance of order statistics. Parameter estimation for the log-logistic distribution based on order statistics is studied. In particular, best linear unbiased estimators (BLUEs) for the location and scale parameters for the log-logistic distribution with known shape parameter are studied. Hill estimator is proposed for estimating the shape parameter.
description: REVSTAT-Statistical Journal, Vol. 16 No. 4 (2018): REVSTAT-Statistical Journal
Comparison of the Average Kappa Coefficients of Binary Diagnostic Tests Done on the Same Subjects
Creators: name: Roldán-Nofuentes, José Antonio
name: Olvera-Porcel, Carmen
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: The average kappa coefficient of a binary diagnostic test is a chance corrected index between the binary diagnostic test and the gold standard, and it depends on the sensitivity and the specificity of the diagnostic test and on the disease prevalence. In this article, several hypothesis tests are studied to compare the average kappa coefficients of two (o more) binary diagnostic tests done on the same subjects. Simulation experiments were carried out to study the type I errors and the powers of the hypothesis tests studied. A program in R was written to solve the problem studied and it can be freely downloaded from the Internet. The results were applied to a real example on the diagnosis of coronary disease.
description: REVSTAT-Statistical Journal, Vol. 16 No. 4 (2018): REVSTAT-Statistical Journal
Likelihood Ratio Test for the Hyper-Block Matrix Sphericity Covariance Structure
Creators: name: R. Correia, Bárbara
name: A. Coelho, Carlos
name: J. Marques, Filipe
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: In this paper the authors introduce the hyper-block matrix sphericity test which is a generalization of both the block-matrix and the block-scalar sphericity tests and as such also of the common sphericity test. This test is a tool of crucial importance to verify elaborate assumptions on covariance matrix structures, namely on meta-analysis and error covariance structures in mixed models and models for longitudinal data. The authors show how by adequately decomposing the null hypothesis of the hyper-block matrix sphericity test it is possible to easily obtain the expression for the likelihood ratio test statistic as well as the expression for its moments. From the factorization of the exact characteristic function of the logarithm of the statistic, induced by the decomposition of the null hypothesis, and by adequately replacing some of the factors with an asymptotic result, it is possible to obtain near-exact distributions that lie very close to the exact distribution. The performance of these near-exact distributions is assessed through the use of a measure of proximity between distributions, based on the corresponding characteristic functions.
description: REVSTAT-Statistical Journal, Vol. 16 No. 3 (2018): REVSTAT-Statistical Journal
Investigating the influence of institutions, politics, organizations, and governance on the COVID-19 response in British Columbia, Canada: a jurisdictional case study protocol
Creators: name: Brubacher, Laura Jane
name: Hasan, Md Zabir
name: Sriram, Veena
name: Keidar, Shelly
name: Wu, Austin
name: Cheng, Michael
name: Lovato, Chris Y.
name: Berman, Peter A.
Publisher: name: BioMed Central
Year: 2022

description: Background Research on public health responses to COVID-19 globally has largely focused on understanding the virus’ epidemiology, identifying interventions to curb transmission, and assessing the impact of interventions on outcomes. Only recently have studies begun to situate their findings within the institutional, political, or organizational contexts of jurisdictions. Within British Columbia (BC), Canada, the COVID-19 response in early 2020 was deemed highly coordinated and effective overall; however, little is understood as to how these upstream factors influenced policy decisions. Methods Using a conceptual framework we developed, we are conducting a multidisciplinary jurisdictional case study to explore the influence of institutional (I), political (P), organizational (O), and governance (G) factors on BC’s COVID-19 public health response in 2020–2021. A document review (e.g. policy documents, media reports) is being used to (1) characterize relevant institutional and political factors in BC, (2) identify key policy decisions in BC’s epidemic progression, (3) create an organizational map of BC’s public health system structure, and (4) identify key informants for interviews. Quantitative data (e.g. COVID-19 case, hospitalization, death counts) from publicly accessible sources will be used to construct BC’s epidemic curve. Key informant interviews (n = 15–20) will explore governance processes in the COVID-19 response and triangulate data from prior procedures. Qualitative data will be analysed using a hybrid deductive–inductive coding approach and framework analysis. By integrating all of the data streams, our aim is to explore decision-making processes, identify how IPOG factors influenced policy decisions, and underscore implications for decision-making in public health crises in the BC context and elsewhere. Knowledge users within the jurisdiction will be consulted to construct recommendations for future planning and preparedness. Discussion As the COVID-19 pandemic evolves, governments have initiated retrospective examinations of their policies to identify lessons learned. Our conceptual framework articulates how interrelations between IPOG contextual factors might be applied to such analysis. Through this jurisdictional case study, we aim to contribute findings to strengthen governmental responses and improve preparedness for future health crises. This protocol can be adapted to and applied in other jurisdictions, across subnational jurisdictions, and internationally.
Residual Analysis with Bivariate INAR(1) Models
Creators: name: M. Popović, Predrag
name: S. Nastić, Aleksandar
name: M. Ristić, Miroslav
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: In this paper we analyze forecasting errors made by random coefficients bivariate integer-valued autoregressive models of order one. These models are based on the thinning operator to support discreteness of data. In order to achieve a comprehensive analysis, we introduce a model that implements a binomial as well as a negative binomial thinning operator. There are two components of the model: survival and innovation. Forecasting errors made by each of these two sources of uncertainty are unobservable in the classic way. Thus, we derive predictive distributions from which we obtain the expected value of each component of the model. We provide an example of residual analysis on real data.
description: REVSTAT-Statistical Journal, Vol. 16 No. 3 (2018): REVSTAT-Statistical Journal
Distribution of a Quadratic Form in Normal Variates
Creators: name: Zhang, Jin
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: It is a well-known theorem in linear models that the idempotency of a matrix is a sufficient and necessary condition for a quadratic form in normal variates to have a chisquare distribution, but its proofs in the early literature were incorrect or incomplete. Driscoll (1999) provided an improved proof, and this article presents a simple proof. More importantly, we establish and prove a generalized theorem.
description: REVSTAT-Statistical Journal, Vol. 16 No. 3 (2018): REVSTAT-Statistical Journal
Which Effect Size Measure is Appropriate for One-Way and Two-Way ANOVA Models?
Creators: name: Yigit, Soner
name: Mendes, Mehmet
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: It is very important to report some effect size measures that will show if the observed differences among the groups are also of practical significance along with statistical significance while reporting statistical analysis results. Performances of four commonly used effect size measures (Eta-Squared, Partial Eta Squared, Omega Squared and Epsilon Squared) were compared for one and two-way ANOVA models under 3000 different conditions. Results of simulation runs showed that the Epsilon and Omega-Squared estimates were quite unbiased when compared to Eta and Partial Eta-Squared which are directly reported by commonly used statistical packages while reporting ANOVA results. Thus, it could be concluded that reporting Epsilon or Omega-Squared is more appropriate to evaluate the practical significance of observed differences along with P-values.
description: REVSTAT-Statistical Journal, Vol. 16 No. 3 (2018): REVSTAT-Statistical Journal
Two-Factor Experiments with Split Units Constructed by Cyclic Designs and Square Lattice Designs
Creators: name: Ozawa, Kazuhiro
name: Mejza, Iwona
name: Mejza, Stanisław
name: Kuriki, Shinji
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: We consider nested row-column designs with split units for a two-factor experiment. The most optimal design in this case is that of using for the whole plots a Latin square while for the subplot treatments with a completely randomized design for each whole plot. Such a design, in fact optimal, utilizes many experimental units and quite a large space. Hence to construct new designs of reduced size of the experiment we use a cyclic design for the whole plot treatments and a square lattice design for the subplot treatments. The proposed designs are generally balanced and they allow for giving the stratum efficiency factors, especially useful to design of experiments.
description: REVSTAT-Statistical Journal, Vol. 16 No. 3 (2018): REVSTAT-Statistical Journal
Association Measures in the Bivariate Correlated Frailty Model
Creators: name: C. Gupta, Ramesh
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: This paper deals with a general bivariate correlated frailty model. This includes the multiplicative as well as the additive frailty effect. The association parameter is studied for the shared as well as the general correlated model. The results for the gamma, the inverse Gaussian and the stable frailty models are derived.
description: REVSTAT-Statistical Journal, Vol. 16 No. 2 (2018): REVSTAT-Statistical Journal
Semi-Parametric Likelihood Inference for Birnbaum–Saunders Frailty Model
Creators: name: Balakrishnan, N.
name: Liu, Kai
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: Cluster failure time data are commonly encountered in survival analysis due to different factors such as shared environmental conditions and genetic similarity. In such cases, careful attention needs to be paid to the correlation among subjects within same clusters. In this paper, we study a frailty model based on Birnbaum–Saunders frailty distribution. We approximate the intractable integrals in the likelihood function by the use of Monte Carlo simulations and then use the piecewise constant baseline hazard function within the proportional hazards model in frailty framework. Thereafter, the maximum likelihood estimates are numerically determined. A simulation study is conducted to evaluate the performance of the proposed model and the method of inference. Finally, we apply this model to a real data set to analyze the effect of sublingual nitroglycerin and oral isosorbide dinitrate on angina pectoris of coronary heart disease patients and compare our results with those based on other frailty models considered earlier in the literature.
description: REVSTAT-Statistical Journal, Vol. 16 No. 2 (2018): REVSTAT-Statistical Journal
Improving Bayesian Mixture Models for Multiple Imputation of Missing Data Using Focused Clustering
Creators: name: P. Reiter, Jerome
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: We present a joint modeling approach for multiple imputation of missing continuous and categorical variables using Bayesian mixture models. The approach extends the idea of focused clustering, in which one separates variables into two sets before estimating the mixture model. Focus variables include variables with high rates of missingness and possibly other variables that could help improve the quality of the imputations. Non-focus variables include the remainder. In this way, one can use a rich sub-model for the focus set and a simpler model for the non-focus set, thereby concentrating fitting power on the variables with the highest rates of missingness. We present a procedure for specifying which variables with low rates of missingness to include in the focus set. We examine the performance of the imputation procedure using simulation studies based on artificial data and on data from the American Community Survey.
description: REVSTAT-Statistical Journal, Vol. 16 No. 2 (2018): REVSTAT-Statistical Journal
Modified Systematic Sampling with Multiple Random Starts
Creators: name: Gupta, Sat
name: Khan, Zaheen
name: Shabbir, Javid
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: Systematic sampling has been facing two problems since its beginning; situational complications, e.g., population size N not being a multiple of the sample size n, and unavailability of unbiased estimators of population variance for all possible combinations of N and n. These problems demand a sampling design that may solve the said problems in a practicable way. In this paper, therefore, a new sampling design is introduced and named as, “Modified Systematic Sampling with Multiple Random Starts”. Linear systematic sampling and simple random sampling are the two extreme cases of the proposed design. The proposed design is analyzed in detail and various expressions have been derived. It is found that the expressions for linear systematic sampling and simple random sampling may be extracted from these expressions. Finally, a detailed efficiency comparison is also carried out in this paper.
description: REVSTAT-Statistical Journal, Vol. 16 No. 2 (2018): REVSTAT-Statistical Journal
Nonparametric Predictive Inference for Reproducibility of Two Basic Tests Based on Order Statistics
Creators: name: P.A. Coolen, Frank
name: N. Alqifari, Hana
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: Reproducibility of statistical hypothesis tests is an issue of major importance in applied statistics: if the test were repeated, would the same overall conclusion be reached, that is rejection or non-rejection of the null hypothesis? Nonparametric predictive inference (NPI) provides a natural framework for such inferences, as its explicitly predictive nature fits well with the core problem formulation of a repeat of the test in the future. NPI is a frequentist statistics method using relatively few assumptions, made possible by the use of lower and upper probabilities. For inference on reproducibility of statistical tests, NPI provides lower and upper reproducibility probabilities (RP). In this paper, the NPI-RP method is presented for two basic tests using order statistics, namely a test for a specific value for a population quantile and a precedence test for comparison of data from two populations, as typically used for experiments involving lifetime data if one wishes to conclude before all observations are available.
description: REVSTAT-Statistical Journal, Vol. 16 No. 2 (2018): REVSTAT-Statistical Journal
title: Kontrol`nye cpiski dlja izucenija i ocenki sostojanija promyslennych ob'jektov, imejuscich vescestva, pregstavljajuscie opacnost' dlja vodnych resurcov
title: Контрольный список № 4: Совместное хранение
titleType: AlternativeTitle
Creators: name: Winkelmann-Oei, Gerhard
name: Platkowski, Jörg
Publisher: name: My University
Year: 2016
Subjects: subject: Gewässerschutz
subject: Risikomanagement
subject: Leitfaden
subject: water protection
subject: installation-related
subject: water pollution
subject: water pollutants
subject: risk management
subject: checklist
subject: guideline
subject: Chemikalien
subject: Chemicals

description: Опираясь на рекомендации международных комиссий по речным бассейнам и водным ресурсам, была разработана концепция контрольных листов, позволяющая эффективно оценить состояние промышленных установок, содержащих вредные для водных ресурсов материалы и растворы. Она включает в себя обзор потенциальных сфер деятельности, а также специальные контрольные листы, распределенные по функциональным единицам, отраслям и областям риска.
Computationally Efficient Goodness-of-Fit Tests for the Error Distribution in Nonparametric Regression
Creators: name: Rivas-Martínez, G.I.
name: Jiménez-Gamero, Maria Dolores
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: Several procedures have been proposed for testing goodness-of-fit to the error distribution in nonparametric regression models. The null distribution of the associated test statistics is usually approximated by means of a parametric bootstrap which, under certain conditions, provides a consistent estimator. This paper considers a goodness-of-fit test whose test statistic is an L2 norm of the difference between the empirical characteristic function of the residuals and a parametric estimate of the characteristic function in the null hypothesis. It is proposed to approximate the null distribution through a weighted bootstrap which also produces a consistent estimator of the null distribution but, from a computational point of view, is more efficient than the parametric bootstrap.
description: REVSTAT-Statistical Journal, Vol. 16 No. 1 (2018): REVSTAT-Statistical Journal
Heuristic Tools for the Estimation of The Extremal Index
Creators: name: Ferreira, Marta
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: Clustering of exceedances of a critical level is a phenomenon that concerns risk managers in many areas. The extremal index θ measures the propensity of the large observations in a dataset to cluster. Thus the estimation of θ is an important issue recurrently addressed in literature. Besides a declustering parameter, inference also depends on a threshold. This choice is actually a crucial topic and is transversal to many other extremal parameters. In this paper we analyze a threshold-free heuristic procedure. We also make comparisons with other heuristic procedures already developed within the extremal index estimation. Our study is based on simulation. We illustrate with an application to environmental data.
description: REVSTAT-Statistical Journal, Vol. 16 No. 1 (2018): REVSTAT-Statistical Journal
Maternal epigenetic clocks measured during pregnancy do not predict gestational age at delivery or offspring birth outcomes: a replication study in metropolitan Cebu, Philippines
Creators: name: Ryan, Calen P.
name: Rege, Raviraj J.
name: Lee, Nanette R.
name: Carba, Delia B.
name: Kobor, Michael S. (Geneticist)
name: MacIsaac, Julia L.
name: Lin, David Tse-Shen, 1982-
name: Atashzay, Parmida
name: Kuzawa, Christopher
Publisher: name: BioMed Central
Year: 2022

description: Adverse birth outcomes, such as early gestational age and low birth weight, can have lasting effects on morbidity and mortality, with impacts that persist into adulthood. Identifying the maternal factors that contribute to adverse birth outcomes in the next generation is thus a priority. Epigenetic clocks, which have emerged as powerful tools for quantifying biological aging and various dimensions of physiological dysregulation, hold promise for clarifying relationships between maternal biology and infant health, including the maternal factors or states that predict birth outcomes. Nevertheless, studies exploring the relationship between maternal epigenetic age and birth outcomes remain few. Here, we attempt to replicate a series of analyses previously reported in a US-based sample, using a larger similarly aged sample (n = 296) of participants of a long-running study in the Philippines. New pregnancies were identified prospectively, dried blood spot samples were collected during the third trimester, and information was obtained on gestational age at delivery and offspring weight after birth. Genome-wide DNA methylation was assessed with the Infinium EPIC array. Using a suite of 15 epigenetic clocks, we only found one significant relationship: advanced age on the epigenetic clock trained on leptin predicted a significantly earlier gestational age at delivery (β = − 0.15, p = 0.009). Of the other 29 relationships tested predicting gestational age and offspring birth weight, none were statistically significant. In this sample of Filipino women, epigenetic clocks capturing multiple dimensions of biology and health do not predict birth outcomes in offspring.
Weibull Lindley Distribution
Creators: name: Asgharzadeh, A.
name: Nadarajah, S.
name: Sharafi, F.
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: A new distribution is introduced based on compounding Lindley and Weibull distributions. This distribution contains Lindley and Weibull distributions as special cases. Several properties of the distribution are derived including the hazard rate function, moments, moment generating function, and Lorenz curve. An estimation procedure by the method of maximum likelihood and a simulation study to assess its performance are given. Three real data applications are presented to show that the new distribution fits better than known generalizations of the Lindley distribution.
description: REVSTAT-Statistical Journal, Vol. 16 No. 1 (2018): REVSTAT-Statistical Journal
Modelling Spatially Sampled Proportion Processes
Creators: name: Paradinas, Iosu
name: Pennino, Maria Grazia
name: López-Quílez, Antonio
name: Marín, Marcial
name: Bellido, José María
name: Conesa, David
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: Many ecological processes are measured as proportions and are spatially sampled. In all these cases the standard procedure has long been the transformation of proportional data with the arcsine square root or logit transformation, without considering the spatial correlation in any way. This paper presents a robust regression model to analyse this kind of data using a beta regression and including a spatially correlated term within the Bayesian framework. As a practical example, we apply the proposed approach to a spatio-temporally sampled fishery discard dataset.
description: REVSTAT-Statistical Journal, Vol. 16 No. 1 (2018): REVSTAT-Statistical Journal
q-Generalized Extreme Value Distribution
Creators: name: B. Provost, Serge
name: Saboor, Abdus
name: M. Cordeiro, Gauss
name: Mansoor, Muhammad
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: Asymmetrical models such as the Gumbel, logistic, Weibull and generalized extreme value distributions have been extensively utilized for modeling various random phenomena encountered for instance in the course of certain survival, financial or reliability studies. We hereby introduce q-analogues of the generalized extreme value and Gumbel distributions, the additional parameter q allowing for increased modeling flexibility. These extended models can yield several types of hazard rate functions, and their supports can be finite, infinite as well as bounded above or below. Closed form representations of some statistical functions of the proposed distributions are provided. It is also shown that they compare favorably to three related distributions in connection with the modeling of a certain hydrological data set. Finally, a simulation study confirms the suitability of the maximum likelihood method for estimating the model parameters.
description: REVSTAT-Statistical Journal, Vol. 16 No. 1 (2018): REVSTAT-Statistical Journal
Supplementary document for 3d virtual histology of the Cerebral Cortex based on Phase-Contrast X-ray tomography - 5505259.pdf
Creators: name: Eckermann, Marina
name: van der Meer, Franziska
name: Cloetens, Peter
name: Ruhwedel, Torben
name: Moebius, Wiebke
name: Stadelmann-Nessler, Christine
name: Salditt, Tim
Publisher: name: Optica Publishing Group
Year: 2025
Subjects: Uncategorized

description: Supplemental Information and Figures
Finding the Optimal Threshold of a Parametric ROC Curve Under a Continuous Diagnostic Measurement
Creators: name: Hwang, Yi-Ting
name: Hung, Yu-Han
name: Chao Wang, Chun
name: Terng, Harn-Jing
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: The accuracy of a binary diagnostic test can easily be assessed by comparing the sensitivity and specificity with the status of respondents. When the result of a diagnostic test is continuous, the assessment of accuracy depends on a specified threshold. The receiver operating characteristic (ROC) curve, which includes all possible combinations of sensitivity and specificity, provides an appropriate measure for evaluating the overall accuracy of the diagnostic test. Nevertheless, in practice, a cutoff value is still required to make easier its clinical usage easier. The determination of a proper cutoff value depends on how important the practitioner views the specificity and sensitivity. Given particular values of specificity and sensitivity, this paper derives the optimal cutoff value under two parametric assumptions on the outcomes of the diagnostic test. Because the optimal cutoff value does not have a closed form, the numerical results are tabulated for some parameter settings to find the optimal cutoff value. Finally, real data are employed to illustrate the use of the proposed method.
description: REVSTAT-Statistical Journal, Vol. 16 No. 1 (2018): REVSTAT-Statistical Journal
Finding primary care : Repurposing physician registration data to generate a regionally accurate list of primary care clinics : Development and validation of an open-source algorithm
Creators: name: Cooper, Ian R.
name: Lindsay, Cameron
name: Fraser, Keaton
name: Hill, Tiffany T.
name: Siu, Andrew
name: Fletcher, Sarah
name: Klimas, Jan
name: Hamilton, Michee-Ana
name: Frazer, Amanda D.
name: Humphrys, Elka
name: Koepke, Kira
name: Hedden, Lindsay
name: Price, Morgan
name: McCracken, Rita
Publisher: name: JMIR Formative Research
Year: 2023

description: Background: Some Canadians have limited access to longitudinal primary care, despite its known advantages for population health. Current initiatives to transform primary care aim to increase access to team-based primary care clinics. However, many regions lack a reliable method to enumerate clinics, limiting estimates of clinical capacity and ongoing access gaps. A region-based complete clinic list is needed to effectively describe clinic characteristics and to compare primary care outcomes at the clinic level. Objective: The objective of this study is to show how publicly available data sources, including the provincial physician license registry, can be used to generate a verifiable, region-wide list of primary care clinics in British Columbia, Canada, using a process named the Clinic List Algorithm (CLA). Methods: The CLA has 10 steps: (1) collect data sets, (2) develop clinic inclusion and exclusion criteria, (3) process data sets, (4) consolidate data sets, (5) transform from list of physicians to initial list of clinics, (6) add additional metadata, (7) create working lists, (8) verify working lists, (9) consolidate working lists, and (10) adjust processing steps based on learnings. Results: The College of Physicians and Surgeons of British Columbia Registry contained 13,726 physicians, at 2915 unique addresses, 6942 (50.58%) of whom were family physicians (FPs) licensed to practice in British Columbia. The CLA identified 1239 addresses where primary care was delivered by 4262 (61.39%) FPs. Of the included addresses, 84.50% (n=1047) were in urban locations, and there was a median of 2 (IQR 2-4, range 1-23) FPs at each unique address. Conclusions: The CLA provides a region-wide description of primary care clinics that improves on simple counts of primary care providers or self-report lists. It identifies the number and location of primary care clinics and excludes primary care providers who are likely not providing community-based primary care. Such information may be useful for estimates of capacity of primary care, as well as for policy planning and research in regions engaged in primary care evaluation or transformation.
Common in Research Software, Hardware and Data: the experience of the SEEKCommons project (slides)
Creators: name: R. Murillo, Luis Felipe
Publisher: name: Zenodo
Year: 2024

description: These are the slides for a keynote address delivered by Luis Felipe R. Murillo, professor of anthropology at University of Notre Dame, on August 1st, 2024, at the Ethical Open Science for Past Global Change Data 2024 Symposium, in Keshena, Wisconsin, on the lands of the Menominee Nation.
The changing role of historic town of Rhodes in the scenario
Creators: name: Maglio, Emma
Publisher: name: Eikonocity. History and Iconography of European Cities and Sities
Year: 2016
Subjects: Architectural heritage, propaganda, iconography.

description: Rhodes was the Hospitaller stronghold until the early modern age. It went through an urban and architectural evolution under the Ottoman and Italian rules. Iconography until the twentieth century shows the search for medieval souvenirs in the Islamic town, the creation of a travel destination and the shifting of the symbolic-geographic idea of city, linked to a new attitude towards built heritage. We will trace the changing role of the historic town in Turkish and Italian ideology and practice.
description: Eikonocity. History and Iconography of European Cities and Sities, Vol 1, No 1 (2016)
Statistical Properties and Sensitivity of a New Adaptive Sampling Method for Quality Control
Creators: name: Do Carmo, Manuel
name: Infante, Paulo
name: M. Mendes, Jorge
Publisher: name: REVSTAT-Statistical Journal
Year: 2018

description: We present a new adaptive sampling method for statistical quality control. In this method, called LSI (Laplace sampling intervals), we use the probability distribution function of the Laplace standard distribution to obtain the sampling instants, depending on a k parameter that allows control of sampling costs. Several algebraic expressions concerning the statistical properties of the LSI method are presented. We compare the LSI method with fixed sampling intervals (FSI) and variable sampling intervals (VSI) methods using a Shewhart X-bar control chart and evaluate the sensitivity of these sampling methods when the lower sampling interval is truncated. The results obtained show that the new method is a viable alternative in various critical contexts and situations.
description: REVSTAT-Statistical Journal, Vol. 16 No. 1 (2018): REVSTAT-Statistical Journal
BDBS + Gaia EDR3: astrometric cleaning of the Milky Way bulge CMDs
Creators: name: Marchetti, Tommaso
name: Johnson, Christian I.
name: Joyce, Meridith
name: Rich, R. Michael
name: Simion, Iulia T.
name: Young, Michael D.
name: Clarkson, William
name: Pilachowski, Catherine A.
name: Michael, Scott
name: Kunder, Andrea
name: Koch-Hansen, Andreas J.
Publisher: name: Zenodo
Year: 2022

description: The Blanco DECam Bulge Survey (BDBS) has imaged more than 200 square degrees of the Southern Galactic bulge, providing photometry in the ugrizY filters for ~250 million unique stars. An accurate cross-match of BDBS with the latest data release (EDR3) of Gaia results in more than 140 million sources with BDBS photometry and Gaia EDR3 photometry and astrometry. In this talk, I will show how Gaia EDR3 parallaxes and proper motions can be used to statistically remove foreground sources, allowing us to produce clean color-magnitude diagrams (CMDs) and transverse kinematic maps for stars in the bulge. We observe kinematic patterns consistent with the X-shaped nature of the bulge, and rotation signatures due to the presence of the bar. I will present cleaned CMDs for over a hundred individual Southern Galactic bulge fields, showing no evidence for a conspicuous young population of stars in the bulge, but confirming previous studies identifying a mean age for the bulge stars of ~10 Gyr. Finally, I will conclude by discussing the implications of our findings in the context of possible formation scenarios for the Milky Way bulge, and the improvements from future Gaia data releases that will allow more precise identification of bulge members.
Transmuted Birnbaum–Saunders Distribution
Creators: name: Bourguignon, Marcelo
name: Leão, Jeremias
name: Leiva, Víctor
name: Santos-Neto, Manoel
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: The Birnbaum–Saunders distribution has been largely studied and applied because of its attractive properties. We introduce a transmuted version of this distribution. Various of its mathematical and statistical features are derived. We use the maximum likelihood method for estimating its parameters and determine the score vector and Hessian matrix for inference and diagnostic purposes. We evaluate the performance of the maximum likelihood estimators by a Monte Carlo study. We illustrate the potential applications of the new transmuted Birnbaum–Saunders distribution by means of three real-world data sets from different areas.
description: REVSTAT-Statistical Journal, Vol. 15 No. 4 (2017): REVSTAT-Statistical Journal
Reliability Estimation in Multistage Ranked Set Sampling
Creators: name: Mahdizadeh, M.
name: Zamanzade, Ehsan
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: A nonparametric reliability estimator based on multistage ranked set sampling is developed. It is shown that the estimator is unbiased and its efficiency relative to the simple random sampling rival is increasing in the number of stages. Numerical experiments are used to illustrate the theoretical findings. The suggested procedure is applied on a sport data set.
description: REVSTAT-Statistical Journal, Vol. 15 No. 4 (2017): REVSTAT-Statistical Journal
Confidence Intervals for Exceedance Probabilities with Application Tto Extreme Ship Motions
Creators: name: Glotzer, Dylan
name: Pipiras, Vladas
name: Belenky, Vadim
name: Campbell, Bradley
name: Smith, Timothy
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: Statistical inference of a probability of exceeding a large critical value is studied in the peaks-over-threshold (POT) approach. The focus is on assessing the performance of the various confidence intervals for the exceedance probability, both for the generalized Pareto distribution used above a selected threshold and in the POT setting for general distributions. The developed confidence intervals perform well in an application to extreme ship motion data. Finally, several approaches to uncertainty reduction are also considered.
description: REVSTAT-Statistical Journal, Vol. 15 No. 4 (2017): REVSTAT-Statistical Journal
Discriminating Between Normal and Gumbel Distributions
Creators: name: Qaffou, Abdelaziz
name: Zoglat, Abdelhak
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: The normal and Gumbel distributions are much alike in practical engineering, in flood frequency and they are similar in appearance, especially for small samples. So the aim of this paper is to discriminate between these two distributions. Considering the logarithm of the ratio of the maximized likelihood (RML) as test statistic, its asymptotic distribution is found under both normal and Gumbel distributions, which can be used to compute the probability of correct selection (PCS). Finally, Monte Carlo (MC) simulations are performed to examine how the asymptotic results work for finite sample sizes.
description: REVSTAT-Statistical Journal, Vol. 15 No. 4 (2017): REVSTAT-Statistical Journal
Estimating Renyi Entropy of Several Exponential Distributions Under an Asymmetric Loss Function
Creators: name: Kayal, Suchandan
name: Kumar, Somesh
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: The present paper takes into account the estimation of the Renyi entropy of several exponential distributions under a linex loss function. The models under study are (i) several exponential distributions with a common scale parameter and unknown but unequal location parameters and (ii) several exponential distributions with a common location parameter and unknown but unequal scale parameters. Improvements over the best affine equivariant estimator are obtained for the first model considering unrestricted and restricted parameter spaces. For the second model, sufficient conditions for improvement over affine and scale equivariant estimators are obtained and consequently, improvements over the maximum likelihood estimator and the uniformly minimum variance unbiased estimator are proposed. Sections on numerical studies have been included after each model to present comparative study of the relative risk performance of the proposed improved estimators.
description: REVSTAT-Statistical Journal, Vol. 15 No. 4 (2017): REVSTAT-Statistical Journal
Estimation Through Array-Based Group Tests
Creators: name: Martins, João Paulo
name: Felgueiras, Miguel
name: Santos, Rui
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: Pooling individual samples for batch testing is a common procedure for reducing costs. The recent use of multidimensional array algorithms, due to the emergence of robotic pooling, is an innovative way of pooling. We show that the two-dimensional arraybased group tests can provide accurate estimates for the prevalence rate even for situations in which the traditional estimators, applied to one-dimensional arrays, are not valid. Hence, a computational script was developed to determine which prevalence rate estimate minimizes the sum of the squared deviations between the number of observed and expected rows and columns whose pooled sample had a positive test result.
description: REVSTAT-Statistical Journal, Vol. 15 No. 4 (2017): REVSTAT-Statistical Journal
Gamma-Admissibility in a Non-Regular Family with Squared-Log Loss Function
Creators: name: Moradi Zahraie, Shirin
name: Zakerzadeh, Hojatollah
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: Review the admissibility of estimators under a vague prior information leads to the concept of gamma-admissibility. In this paper, the problem of estimation in a nonregular family of distributions under a squared log error loss function is considered. We find sufficient condition for a generalized Bayes estimator of a parametric function to be gamma-admissible. Some examples are given.
description: REVSTAT-Statistical Journal, Vol. 15 No. 4 (2017): REVSTAT-Statistical Journal
Optimal B-Robust Estimators for the Parameters of the Generalized Half-Normal Distribution
Creators: name: Zehra Doğru, Fatma
name: Murat Bulut, Y.
name: Arslan, Olcay
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: The purpose of this study is to propose robust estimators by using optimal B-robust (OBR) estimation method (Hampel et al. [5]) for the parameters of the generalized half-normal (GHN) distribution. After given the robust estimators, we provide a small simulation study to compare its performance with the estimators obtained from maximum likelihood (ML) estimation method. We also give a real data example to illustrate the performance of the proposed estimators.
description: REVSTAT-Statistical Journal, Vol. 15 No. 3 (2017): REVSTAT-Statistical Journal
Highly D-Efficient Designs with Nonnegatively Correlated Observations
Creators: name: Katulska, Krystyna
name: Smaga, Lukasz
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: In the most difficult case where the number of observations n ≡ 3 (mod 4), high D-efficiency of certain chemical balance weighing designs under completely symmetric covariance matrix of errors is shown. It is also proved that D-optimal design may depend on the values of the correlation coefficient.
description: REVSTAT-Statistical Journal, Vol. 15 No. 3 (2017): REVSTAT-Statistical Journal
Supplementary document for 3d virtual histology of the Cerebral Cortex based on Phase-Contrast X-ray tomography - 5505259.pdf
Creators: name: Eckermann, Marina
name: van der Meer, Franziska
name: Cloetens, Peter
name: Ruhwedel, Torben
name: Moebius, Wiebke
name: Stadelmann-Nessler, Christine
name: Salditt, Tim
Publisher: name: Optica Publishing Group
Year: 2021
Subjects: Uncategorized

description: Supplemental Information and Figures
Modified Borel–Tanner (Mbt) Regression Model
Creators: name: Gómez-Déniz, Emilio
name: Vázquez-Polo, Francisco J.
name: García, Victoriano
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: A new one-parameter family of discrete distributions is presented. It has some advantages against the Poisson distribution as a suitable model for modelling data with a high frequencies of zeros and showing over-dispersion (variance larger than the mean). The distribution is obtained from a simple modification of the Borel–Tanner distribution, which has not received attention from the statistical community in the past. We also propose a generalized regression model which can be used for a count dependent variable, when the above features are observed, as an alternative to the well-known Poisson regression model, among others. Maximum likelihood estimation is investigated and illustrated with an example of interrelation between fatalities in trucks accidents on American roads and some covariates considered.
description: REVSTAT-Statistical Journal, Vol. 15 No. 3 (2017): REVSTAT-Statistical Journal
Some Inadmissibility Results for Estimating Quantile Vector of Several Exponential Populations with a Common Location Parameter
Creators: name: Ranjan Tripathy, Manas
name: Kumar, Somesh
Publisher: name: REVSTAT-Statistical Journal
Year: 2017

description: Suppose independent random samples are taken from k (≥ 2) exponential populations with a common and unknown location parameter “µ” and possibly different unknown scale parameters σ1,σ2,...,σk respectively. The estimation of θ = (θ1,θ2,...,θk); where θi is the quantile of the i th population, has been considered with respect to either a sum of squared error loss functions or sum of quadratic losses. Estimators based on maximum likelihood estimators (MLEs) and uniformly minimum variance unbiased estimators (UMVUEs) for each component θi have been obtained. An admissible class of estimators has been obtained. Improvement over an estimator based on UMVUEs is obtained by an application of the Brewster–Zidek technique. Further, classes of equivariant estimators are derived under affine and location groups of transformations and some inadmissibility results are proved. Finally, a numerical comparison of risk performance of all proposed estimators has been done and the recommendations are made for the use of these estimators.
description: REVSTAT-Statistical Journal, Vol. 15 No. 3 (2017): REVSTAT-Statistical Journal