Optimal experimental plan for multi-level stress testing with Weibull regression under progressive Type-II extremal censoring

In the design of constant-stress life-testing experiments, the optimal allocation in a multi-level stress test with Type-I or Type-II censoring based on the Weibull regression model has been studied in the literature. Conventional Type-I and Type-II censoring schemes restrict our ability to observe extreme failures in the experiment and these extreme failures are important in the estimation of upper quantiles and understanding of the tail behaviors of the lifetime distribution. For this reason, we propose the use of progressive extremal censoring at each stress level, whereas the conventional Type-II censoring is a special case. The proposed experimental scheme allows some extreme failures to be observed. The maximum likelihood estimators of the model parameters, the Fisher information, and asymptotic variance–covariance matrices of the maximum likelihood estimates are derived. We consider the optimal experimental planning problem by looking at four different optimality criteria. To avoid the computational burden in searching for the optimal allocation, a simple search procedure is suggested. Optimal allocation of units for two- and four-stress-level situations is determined numerically. The asymptotic Fisher information matrix and the asymptotic optimal allocation problem are also studied and the results are compared with optimal allocations with specified sample sizes. Finally, conclusions and some practical recommendations are provided.     

Developing a restricted two-parameter Liu-type estimator: A comparison of restricted estimators in the binary logistic regression model

In the context of estimating regression coefficients of an ill-conditioned binary logistic regression model, we develop a new biased estimator having two parameters for estimating the regression vector parameter β when it is subjected to lie in the linear subspace restriction Hβ = h. The matrix mean squared error and mean squared error (MSE) functions of these newly defined estimators are derived. Moreover, a method to choose the two parameters is proposed. Then, the performance of the proposed estimator is compared to that of the restricted maximum likelihood estimator and some other existing estimators in the sense of MSE via a Monte Carlo simulation study. According to the simulation results, the performance of the estimators depends on the sample size, number of explanatory variables, and degree of correlation. The superiority region of our proposed estimator is identified based on the biasing parameters, numerically. It is concluded that the new estimator is superior to the others in most of the situations considered and it is recommended to the researchers.     

Feminist Politics in Contemporary Turkey: Neoliberal Attacks,Feminist Claims to the Public

This article aims to offer a critical reading of the feminist claims to the public sphere in Turkey in the 2000s when there was transformation in the way public and private spheres are defined. We try to link the feminist claims to the public with the shifts in the patriarchal regime of the country in the decade. The main argument of the article is that feminist politics of the 2000s had the potential for an alternative imagination of the public and that they also faced the risk of assimilation into the de-/re-publicization process of the same period. The article starts with a brief outline of the post-1980 period, which hosted both the emergence of independent feminist organizing and the neoliberal restructuration of Turkey’s politics. It continues with the analysis of the Justice and Development Party’s terms in government, as the consolidation of neoliberal restructuration process. We conclude with the (possible) feminist interventions to the new mode of patriarchy that emerges out of this process.     

Export, Import and Economic Growth: The Case of Transition Economies

This study analyses the relationships between export, import and economic growth for the 13 transition economies. Empirical results show that there is a unidirectional causality from economic growth to export. Empirical findings show that the growth-led export hypothesis is valid in those countries and growth is rather shaped by increase in import demand.

Traces of the Second Demographic Transition in Four Selected Countries in Central and Eastern Europe: Union Formation as a Demographic Manifestation

Using data from the first round of the national Gender and Generations Surveys of Russia, Romania, and Bulgaria, and from a similar survey of Hungary, which were all collected in recent years, we study rates of entry into marital and non-marital unions. We have used elements from the narrative of the Second Demographic Transition (SDT) as a vehicle to give our analysis of the data from the four countries some coherence, and find what can be traces of the SDT in these countries. The details vary by country; in particular, latter-day developments in union formation patterns did not start at the same time in all the countries, but in our assessment it began everywhere before communism fell, that is, before the societal transition to a market economy got underway in 1990.

The role of emotions during the Arab Spring in Tunisia and Egypt in light of repertoires

ABSTRACT

This article examines the role of emotions during the Arab Spring in Tunisia and Egypt in the context of collective level emotions in mobilizations. Emotions are understood as a catalyst whose mechanism of action is performed through repertories. This article seeks to answer how emotions, having a triggering role, are performed through repertoires while accelerating mobilization against authoritarian orders, creating the intersection of individual and collective level emotions in public spheres of Tunisia and Egypt, and thus affecting the transnational diffusion of emotions. The significant reason to address emotions is to explain what stimulated the Arab Spring and how it spread over the region starting from Tunisia and Egypt. This article synthesizes two literatures: International Relations (IR) and social movements studies in light of emotions and components of repertoires which are as follows: collective action, collective identity, symbolic politics, network society and information politics.     

Gender Inequalities in Academic Innovation and Enterprise: A Bourdieuian Analysis

This paper demonstrates that engagement in innovation and enterprise activity in SET departments within three UK universities is, in part, gendered. A Bourdieuian approach is adopted to identify underlying structures and practices that have causal powers to generate gender‐based inequalities. Drawing on empirical research with 52 participants, this study reveals gendered science enterprise experiences, characterized by a field that is considered strong in shaping the habitus and presenting stark options to women in pursuit of their careers. It demonstrates the multilayered nature of the fields that shape gendered experiences and resultant inequalities by taking into account individual dispositions of academics and their habitus, including their science enterprise experience and the wider commercial field beyond the university, and generates a number of implications for practice and policy.     

RCEV heteroscedasticity test based on the studentized residuals

All the usual heteroscedasticity tests in the statistics and econometrics literature are based on raw residuals. Although the raw residuals are heteroscedastic, studentized residuals can still be homoscedastic. In this study, the version of Çelik’s RCEV heteroscedasticity test which is based on studentized residuals is introduced.