A group sequential test for the inverse Gaussian mean

The present paper deals with the development of a group sequential test when response variable has an inverse Gaussian distribution with known scale parameter.     

Max Weinreich,assimilation and the social politics of Jewish nation-building

Through an analysis of the methodological and theoretical writings of Max Weinreich that were devoted to the inter-war Jewish youth research programme at the Jewish Scientific Institute (YIVO), this article discusses the ideological and political assumptions that lay behind this scientific project. Deconstructing the main research categories of the project, the author presents ways in which Weinreich and his associates constructed the Jewish nation and its place in the new inter-war political and social reality. This reality was seen in a complex manner, as a simultaneous chance for Jewish modernisation, upward mobility, productivisation, and as a response to the threat of modern state institutions that were introducing discriminatory policies, and, most importantly, assimilation. The last process was seen as the biggest danger, which could fragment and finally even dissolve the essentialist, secular and national model of Jewish community as envisioned by Max Weinreich and YIVO. The author shows how the essentialist vision of the nation omnipotent in inter-war Poland (among both Polish and Jewish communities) introduced unresolved tension between the need for social and cultural integration of the Jews, which was important for Weinreich and his circle, and the simultaneous aim of building a culturally and politically coherent Jewish nation. Further discussion shows how this kind of perception of social reality transformed a scientific research project into a kind of social intervention and nation-building programme, comparable to the ideologies of Jewish national secularist political parties. While presenting itself as a universal, national institution and addressing its call to all Jewish youth, YIVO promoted a particular political view of the Jewish nation and its tradition, history and religion. By engaging Jewish youth in a research programme devoted to its “personality,” one of the hidden aims of the project was to influence the political and social consciousness of Eastern Europe's Jewish youth.     

Amphibians in an urban environment: a case study from a central European city (Wrocław,Poland)

Urban Ecosystems - In 2016, we studied the occurrence of amphibians in 231 selected ponds in the city of Wroc?aw (Lower Silesia, Poland) and confirmed the occurrence of 10 species: Bombina...     

A Bayesian Approach to the Estimation of Expected Cell Counts by Using Log-Linear Models

ABSTRACT

In this article, Bayesian estimation of the expected cell counts for log-linear models is considered. The prior specified for log-linear parameters is used to determine a prior for expected cell counts, by means of the family and parameters of prior distributions. This approach is more cost-effective than working directly with cell counts because converting prior information into a prior distribution on the log-linear parameters is easier than that of on the expected cell counts. While proceeding from the prior on log-linear parameters to the prior of the expected cell counts, we faced with a singularity problem of variance matrix of the prior distribution, and added a new precision parameter to solve the problem. A numerical example is also given to illustrate the usage of the new parameter.     

Disruptions in tightly coupled supply chain networks: the case of the US offshore oil industry

Managers have paid increasing attention to the exposure of their supply chains to disruptions and seek ways to mitigate supply chain vulnerability. The interconnectedness of tightly coupled supply chain networks makes this a challenging task, because interconnectedness and tight coupling of nodes in the network lead to an amplification of the actual risk exposure. This phenomenon can be attributed to the propagation of losses through the network, which exhibits certain dynamics. In order to investigate this mechanism, we studied the complex supply chain network of the oil industry in the Gulf of Mexico. Our results provide an estimate of the economic impact of eventual random and hurricane-related disruptions and can be used as a decision support tool for risk management of supply disruptions in interconnected supply chain networks.     

Autoregressive Model with Partial Forgetting within Rao-Blackwellized Particle Filter

The authors are concerned with Bayesian identification and prediction of a nonlinear discrete stochastic process. The fact that a nonlinear process can be approximated by a piecewise linear function advocates the use of adaptive linear models. They propose a linear regression model within Rao-Blackwellized particle filter. The parameters of the linear model are adaptively estimated using a finite mixture, where the weights of components are tuned with a particle filter. The mixture reflects a priori given hypotheses on different scenarios of (expected) parameters' evolution. The resulting hybrid filter locally optimizes the weights to achieve the best fit of a nonlinear signal with a single linear model.     

A generalized Gumbel distribution and its parameter estimation

ABSTRACT

In this article, main characteristics of a generalized Gumbel (GG) distribution are derived. Parameter estimation with method of moments, maximum likelihood, and Bayesian approaches are demonstrated. Due to the ranges of its skewness and kurtosis, it is satisfactory for fitting a wide variety of datasets. Also, it can be used to model block maxima or minima data due to its close connection with the standard Gumbel distribution. It is demonstrated that the GG distribution fits more accurately than both of the standard Gumbel and generalized extreme value distributions to block maxima data under specific conditions.     

Estimating potential output in developing countries

This paper describes a parsimonious methodology employed by the World Bank for estimating potential output using the production function method. Despite the necessity of strong assumptions, sensitivity analysis suggests the reported estimates for 159 countries are robust to alternative specifications. Moreover, for the majority of countries estimated output gaps are positively correlated with inflation acceleration and negatively correlated with current account balances. An examination of estimated output gaps and post-crisis economic developments in several middle-income countries suggest that the methods can play a useful role in guiding macroeconomic policy.