A new bivariate exponential distribution for modeling moderately negative dependence

This paper introduces a new bivariate exponential distribution, called the Bivariate Affine-Linear Exponential distribution, to model moderately negative dependent data. The construction and characteristics of the proposed bivariate distribution are presented along with estimation procedures for the model parameters based on maximum likelihood and objective Bayesian analysis. We derive Jeffreys prior and discuss its frequentist properties based on a simulation study and MCMC sampling techniques. A real data set of mercury concentration in largemouth bass from Florida lakes is used to illustrate the methodology.     

Minimal circular balanced repeated measurement designs in unequal period sizes

Abstract

Repeated measurement designs (RMDs) are widely used in medicine, pharmacology, animal sciences and psychology. In these fields, there are several situations where these designs should be used in periods of different sizes. With the use of RMD, residual effects or carry over effects may arise and balanced RMDs are solution to this problem. In this article, therefore, some infinite series are developed through method of cyclic shifts to obtain circular balanced repeated measurements designs in periods of two different sizes.     

Multiple dependent state repetitive sampling plans based on one-sided process capability indices

In this research, multiple dependent state and repetitive group sampling are used to design a variable sampling plan based on one-sided process capability indices, which consider the quality of the current lot as well as the quality of the preceding lots. The sample size and critical values of the proposed plan are determined by minimizing the average sample number while satisfying the producer's risk and consumer's risk at corresponding quality levels. In addition, comparisons are made with the existing sampling plans [Pearn and Wu (2006a Pearn, W. L., and C. W. Wu. 2006a. Critical acceptance values and sample sizes of a variables sampling plan for very low fraction of defectives. Omega: International Journal of Management Science 34 (1):90–101.[Crossref], [Web of Science ®] , [Google Scholar]), Yen et al. (2015 Yen, C. H., C. H. Chang, and M. Aslam. 2015. Repetitive variable acceptance sampling plan for one-sided specification. Journal of Statistical Computation and Simulation 85 (6):1102–16.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar])] in terms of average sample number and operating characteristic curve. Finally, an example is provided to illustrate the proposed plan.     

Issues in intervention with battered women in collectivist societies

Over the past three decades, several models for individual and group intervention with battered women have been developed. The common assumption underlying all of these models is that violence and abuse are never appropriate in an intimate relationship, and that battered women have a basic right to safety, which is not negotiable. Because almost all of those models were developed in the individualistic contexts of Western societies, some questions and concerns have been raised as to their suitability for intervention with battered women in collectivist contexts. In this article, we explore the characteristics of collectivist societies based on the conceptual framework of Triandis, Brislin, and Hui, (1988) which focuses on five dimensions: the self, attitudes, values, activities, and behaviors. Furthermore, we explore each of those dimensions and their relevance to various aspects of wife abuse in collectivist societies, such as the way that battered women cope with violence against them, and possibilities for professional intervention.     

Extending the Bradley–Terry model for paired comparisons to accommodate weights

In the method of paired comparisons (PCs), treatments are compared on the basis of qualitative characteristics they possess, in the light of their sensory evaluations made by judges. However, there may emerge the situations where in addition to qualitative merits/worths, judges may assign quantitative weights to reflect/specify the relative importance of the treatments. In this study, an attempt is made to reconcile the qualitative and the quantitative PCs through assigning quantitative weights to treatments having qualitative merits using/extending the Bradley–Terry (BT) model. Behaviors of the existing BT model and the proposed weighted BT model are studied through the test of goodness-of-fit. Experimental and simulated data sets are used for illustration.     

Savings–Investment Correlation and Capital Outflow: The Case of Pakistan

This study explores the savings–investment relationship in the context of financial liberalization and flexible exchange rate regime in Pakistan. Ng–Perron test is employed to examine the order of integration of the variables used in the model. For long-run analysis, ARDL bounds testing approach is used and short-run dynamics are captured from error correction model (ECM). Time series data are utilized covering the period 1976–2006. Empirical findings indicate that in the case of Pakistan, there is a weak correlation between savings and investment. The study suggests that in the presence of inadequate capital mobility within the country, domestic investors have financed investment projects from international market. Furthermore, devaluation and inflation have stimulated investment activities in the country and significantly contributed in closing the gap between domestic savings and investment.     

On the identification of extreme outliers and dragon-kings mechanisms in the upper tail of income distribution

The presence of extreme outliers in the upper tail data of income distribution affects the Pareto tail modeling. A simulation study is carried out to compare the performance of three types of boxplot in the detection of extreme outliers for Pareto data, including standard boxplot, adjusted boxplot and generalized boxplot. It is found that the generalized boxplot is the best method for determining extreme outliers for Pareto distributed data. For the application, the generalized boxplot is utilized for determining the exreme outliers in the upper tail of Malaysian income distribution. In addition, for this data set, the confidence interval method is applied for examining the presence of dragon-kings, extreme outliers which are beyond the Pareto or power-laws distribution.     

Time-truncated attribute sampling plans using EWMA for Weibull and Burr type X distributions

Acceptance sampling, widely used in various production industries, is a very vital tool of quality control. In this paper, a new attribute acceptance-sampling plan is developed based on the exponentially weighted moving average statistic under a time-truncated life test when the product lifetime follows the Weibull distribution or the Burr type X distribution. The performance measures such as the probability of acceptance and the average sample number are derived. Tables are constructed for the selection of optimal parameters of the proposed sampling plan so as to minimize the average sample number satisfying the producer's and the consumer's risks. Illustrative example is also given for the application of the proposed plan. It is also shown that the proposed plan requires a smaller sample size compared to the single sampling plan.     

Specific niche requirements drive long-term survival and growth of translocated epiphytic orchids in an urbanised tropical landscape

Urbanisation is expanding at an unprecedented rate, affecting multiple taxa the world over. Ex situ conservation practices in urban areas (e.g. managed relocation) can help mitigate species extinction. However, systematic evaluations of ex situ practices and quantification of niche spaces, especially in urban areas, are largely lacking. Using epiphytic orchids as a study system, we translocated 13 propagated native species (2251 individuals) on 99 host trees across six urban sites. After 5 years, 12 of 13 species showed survival rates above 50% and 9 of 11 species exhibited positive growth. Generalised linear mixed models revealed that species and presence of humus corresponded to orchid survival, whereas the fork microsite and height from ground corresponded to orchid growth. Species-wise, the biophysical factors that were associated with survival and growth varied widely, with 7 of 11 species showing distinct interactions with more than one factor. Notably, the presence of humus and relative humidity influenced the survival of 4 of 11 species. This study suggests that managed relocation can serve as a viable conservation strategy for native orchids and possibly other epiphytes as well. We propose that species-specific niche requirements are identified and integrated into intervention actions.