Some reliability characteristics and stochastic ordering of series and parallel systems of bivariate generalized exponential distribution

In this paper, the reliability properties of two-component parallel and series systems are considered for bivariate generalized exponential (BVGE) distribution introduced by Kundu and Gupta [Bivariate generalized exponential distribution. J Multivar Anal. 2009;100:581–593]. For this model, the moments and mean residual life functions of these systems and the regression mean residual life function are derived. Stochastic comparisons of series and parallel systems of BVGE distribution are investigated. Moreover, various ordering results for the comparisons of series and parallel systems arising from BVGE random vectors are obtained with respect to the usual stochastic, reversed hazard rate and likelihood ratio orderings.     

A test statistic to choose between Liu-type and least-squares estimator based on mean square error criteria

In this study, the necessary and sufficient conditions for the Liu-type (LT) biased estimator are determined. A test for choosing between the LT estimator and least-squares estimator is obtained by using these necessary and sufficient conditions. Also, a simulation study is carried out to compare this estimator against the ridge estimator. Furthermore, a numerical example is given for defined test statistic.     

Reactions to cyberbullying among high school and university students

In this study, behavioral and emotional reactions to cyberbullying were investigated by surveying 567 undergraduate-level university students and 211 high school students. Among the study participants, 170 of the undergraduates (29.98%) and 120 of the high school students (56.87%) reported that they had recently been cyberbullied. A four-factor scale with 37 items was used to investigate the behavioral cyberbullying reactions of victimized students. The four factors were revenge, countermeasure, negotiation and avoidance. An additional two-factor scale with 11 items was used to classify victimized students’ emotional reactions as either internalizing or externalizing. Explained variance values of both scales were above 50%, and the factors were found to have acceptable internal consistency coefficients. Behavioral and emotional reactions varied according to gender and school level. Computer self-efficacy and internet use were associated with different reaction types.     

On residual lifetime of coherent systems after the rth failure

In this article we study the residual lifetime of a coherent system after the rth failure, i.e. the time elapsed from the rth failure until the system failure given that the system operates at the time of the rth failure. We provide a mixture representation for the corresponding residual lifetime distribution in terms of signature. We also obtain some stochastic ordering results for the residual lifetimes.     

A Midsummer Night’s Coup: Performance and Power in Turkey’s July 15 Coup Attempt

Occurring at a time when military interventions appeared to be a matter of the past, the coup attempt of July 15, 2016 left a major mark on Turkish society and politics. This article approaches the July 15 coup attempt as a contingent and transformative event and investigates how symbolic processes helped determine its immediate outcome as well as its cultural, social, and political consequences. Linking the sociological literature on events with social performance theory, the study argues that the putschists’ ineffectiveness in projecting legitimacy and power in the critical hours of the coup attempt significantly contributed to its failure. The retrospective construction of an authoritative “Narrative of July 15” in the following weeks, on the other hand, enabled the government to implement specific institutional changes in the cultural, economic, and political domains. The study proposes a two-step analysis for the cultural construction of political events and suggests that social performance theory provides useful analytical tools for tracing the course and explaining the outcome of this process.     

Robust trading mechanisms over 0/1 polytopes

The problem of designing a trade mechanism (for an indivisible good) between a seller and a buyer is studied in the setting of discrete valuations of both parties using tools of finite-dimensional optimization. A robust trade design is defined as one which allows both traders a dominant strategy implementation independent of other traders’ valuations with participation incentive and no intermediary (i.e., under budget balance). The design problem which is initially formulated as a mixed-integer non-linear non-convex feasibility problem is transformed into a linear integer feasibility problem by duality arguments, and its explicit solution corresponding to posted price optimal mechanisms is derived along with full characterization of the convex hull of integer solutions. A further robustness concept is then introduced for a central planner unsure about the buyer or seller valuation distribution, a corresponding worst-case design problem over a set of possible distributions is formulated as an integer linear programming problem, and a polynomial solution procedure is given. When budget balance requirement is relaxed to feasibility only, i.e., when one allows an intermediary maximizing the expected surplus from trade, a characterization of the optimal robust trade as the solution of a simple linear program is given. A modified VCG mechanism turns out to be optimal.     

An Examination of Factors Affecting Economic Status and Finances Satisfaction of Families: A Comparison of Metropolitan and Rural Areas

Research on the family financial management behavior has gained a great impetus over 30 years. There has been a growing interest in the question of how families organize or manage their economic resources and financial satisfaction. The main purpose of this study is to examine factors affecting financial behaviors and financial satisfaction of families who live in metropolitan and rural areas. Participants in the study consist of women who are married and dwelling in Ankara and Karabuk cities of Turkey. A total of 3,046 female (with an approximate 87 % participation rate) are participated in the study on a voluntary (Ankara n = 1,300; Karabuk n = 1,746). Results indicated that 45.4 % of females have determined that economic decision making are always shared by couples (Ankara 41.9 %; Karabuk 47.9 %). Among women who lived in Ankara (62.3 %) have not saving their income, while the group of Karabuk (51.4 %) have sometimes saving. Similar results have been found in terms of the expenditure behaviors among the families who are living in both of the metropolitan and rural areas. The rates of the families living both in Ankara and Karabuk who state that they have become indebted due to various reasons (Ankara 56.5 %; Karabuk 72.9 %) is higher compared to those who state they have not become indebted. Among the females who stated that they are “very dissatisfied” from their savings behavior, “satisfied” with their expenditure behaviors and “dissatisfied” with their debt behaviors are higher percentage (50.6 %, 47.9 %, and 48.3 % respectively).     

Measuring and Understanding Urban Parks’ Contribution to Quality of Life in Istanbul

This study details an application of an improved Water Poverty Index (iWPI) to investigate and assess state of water resources in 53 African countries for the period 2000–2012 with a special focus on an international comparison of water poverty among northern and sub-Saharan countries. A multi-faceted approach that combines physical estimates of water availability with socio-economic drivers of poverty and environmental factors, has been used to do such comparison. It is with this in mind that the iWPI was developed based on the theoretical foundations and recent development of the water poverty approach. This would permit an inclusive comprehension of the crosscutting nature of water issues and their impacts on human wellbeing and environment. The results highlight an obvious dissimilarity of water poverty situation between more developed, but water-poor countries located principally in North Africa with that of lower-income and water-rich countries in sub-Saharan region. This can be used to inform policy makers, governments, donors and other stakeholders to assist in prioritization of appropriate policies to be taken towards better service delivery and sustainable water management across space and time.     

Efficiency evaluations with context-dependent and measure-specific data envelopment approaches: An application in a World Bank supported project

We evaluate the efficiency of decision making units (DMUs) in a World Bank supported Social Risk Mitigation Project (SRMP) in Turkey through context-dependent and measure-specific data envelopment analysis (DEA) approaches. The results suggest that the efficiency evaluations with context-dependent and measure-specific DEA play various roles in an organization such as setting attainable targets to DMUs, setting long and short term targets to DMUs separately, grouping of DMUs, and improving internal competition between DMUs. Four main contributions of this study can be summarized as follows. Firstly, the study shows the applicability of context-dependent and measure-specific DEA methodologies in a World Bank supported large scale project to increase the effectiveness of the project. Secondly, it outlines some important managerial conclusions of context-dependent DEA clustering approach. Moreover, we propose an alternative approach for attractiveness scores computations in case of exogenous group formations. Finally, the study proposes and applies measure-specific version of context-dependent DEA approach.