An alternative method correcting BDR type of heteroskedasticity by the weighting re-estimated absolute residuals

The aim of this paper is to introduce a new method which corrects residual variances for the butterfly distributed residuals (BDR). Distribution theory, confidence intervals, and tests of hypotheses are valid and meaningful only if the standard regression assumptions are satisfied. Heteroskedasticity is one of the violations of these assumptions and BDR is another type of heteroskedasticity. This study reveals an alternative approach to correct the BDR type of heteroskedasticity by the weighting re-estimated absolute residuals (WRAR). After giving brief information about heteroskedasticity and BDR type of heteroskedasticity, WRAR is introduced. WRAR and the usual variance stabilizing techniques are compared on multiple and simple regression models.     

Organizational refinements of Nash equilibrium

Theory and Decision - Strong Nash equilibrium (see Aumann, 1959) and coalition-proof Nash equilibrium (see Bernheim et al., 1987) rely on the idea that players are allowed to form coalitions and...     

Reliability of semi-Markov missions

We consider a device that is designed to perform missions consisting of a random sequence of phases or stages with random durations. The mission process is described by a Markov renewal process and the system is a complex one consisting of a number of components whose lifetimes depend on the phases of the mission. We discuss models and tools to compute system, mission, and phase reliabilities using Markov renewal theory. A simplified model involving a mission-based system with maximal repair is analyzed first, and the results are then extended to the case where there is no repair using intrinsic aging concepts. Our objective is to focus on computation of system reliability for these two possible extreme cases.     

Variance Estimation for Fractional Brownian Motions with Fixed Hurst Parameters

Some real-world phenomena in geo-science, micro-economy, and turbulence, to name a few, can be effectively modeled by a fractional Brownian motion indexed by a Hurst parameter, a regularity level, and a scaling parameter σ², an energy level. This article discusses estimation of a scaling parameter σ² when a Hurst parameter is known. To estimate σ², we propose three approaches based on maximum likelihood estimation, moment-matching, and concentration inequalities, respectively, and discuss the theoretical characteristics of the estimators and optimal-filtering guidelines. We also justify the improvement of the estimation of σ² when a Hurst parameter is known. Using the three approaches and a parametric bootstrap methodology in a simulation study, we compare the confidence intervals of σ² in terms of their lengths, coverage rates, and computational complexity and discuss empirical attributes of the tested approaches. We found that the approach based on maximum likelihood estimation was optimal in terms of efficiency and accuracy, but computationally expensive. The moment-matching approach was found to be not only comparably efficient and accurate but also computationally fast and robust to deviations from the fractional Brownian motion model.     

Quantal models: a review with additional methodological development

Analysis of quantal models is a particular aspect of the general problem of investigating multimodality. The distinction is that the spacings between modes are integral multiples of some unspecified fundamental unit and that the number of modes is not defined. Such semi-structured models arise in a wide variety of contexts such as biology, cosmology, archaeology and molecular physics. This paper presents a brief review of their historical development in such areas as an aid to their recognition in other contexts as well as giving guidance to their analysis from the statistical viewpoint. The available methodology for their analysis is collated into a coherent and self-contained account, establishing various optimality properties under particular parametric distributional assumptions. An illustrative power study shows how dependence on sample size and failure of assumptions such as underlying distribution, origin of measurements and independence affect the power of various analyses. These aspects are illustrated by an example from developmental biology.     

National conceptions,transnational solidarities: Turkey,Islam and Europe

In this article, I examine the interplay between the institutionalization of Islam in Europe and the transnationalism of Turkey's Directorate for Religious Affairs (Diyanet). Based on extensive fieldwork in Turkey, Austria, Belgium, France and Germany, I demonstrate not only the salience of the nation‐state prerogative on the part of both European states and the Turkish state but also the tension between national conceptions of Muslim identity on both sides amid transnational solidarities. I also argue that, to a certain extent, European policies of detransnationalizing the Muslim field in Europe also intersect with the Diyanet's transnational politics vis‐à‐vis Turkish/Muslim immigrants in their common resistance to the deculturalization of Muslims in Europe. While European countries try to nationalize their respective Muslim communities into their cultural and juridical framework through reterritorialization, the Diyanet has increasingly deterritorialized its activities to preserve a Muslim identity engrained in Turkishness – hence, the coexistence of both a tension and mutual accommodation between Europe and Turkey.     

A novel feature selection scheme for high-dimensional data sets: four-Staged Feature Selection

Classification of high-dimensional data set is a big challenge for statistical learning and data mining algorithms. To effectively apply classification methods to high-dimensional data sets, feature selection is an indispensable pre-processing step of learning process. In this study, we consider the problem of constructing an effective feature selection and classification scheme for data set which has a small number of sample size with a large number of features. A novel feature selection approach, named four-Staged Feature Selection, has been proposed to overcome high-dimensional data classification problem by selecting informative features. The proposed method first selects candidate features with number of filtering methods which are based on different metrics, and then it applies semi-wrapper, union and voting stages, respectively, to obtain final feature subsets. Several statistical learning and data mining methods have been carried out to verify the efficiency of the selected features. In order to test the adequacy of the proposed method, 10 different microarray data sets are employed due to their high number of features and small sample size.     

Difficulties in Diagnosing Sexual Abuse in Children with Condyloma Acuminata in Turkey

Human papillomavirus is responsible for anogenital warts and could be regarded as an indicator of possible sexual abuse in children. A genital wart was detected during an investigation of anti–hepatitis C virus positivity in a four-year-old male patient. No pathological findings of another sexually transmitted disease were found except complete cleft palate and circumferential lesions in the perianal region. No family member was anti-hepatitis C virus positive, but the patient's uncle and his wife had genital condylomata. Although detailed physical examination uncovered no other findings indicative of sexual abuse, suspicion of abuse could not be eliminated. Therefore, we wanted to draw the attention of health professionals to the association of anogenital warts and sexual abuse.     

“Are We Doing Fine?” The Views on Poverty Reduction Strategies Among Front-Line Workers in the Field of Social Assistance in Turkey

ABSTRACT

This research highlights the views of front-line workers in the social assistance system in Turkey about the strategies of poverty reduction and the effectiveness of the assistance given by Social Assistance and Solidarity Foundations (SASFs) to the poor. The data were gathered from 33 employees from the 8 SASF offices in Ankara, Turkey. The results show that the majority of the participants agree with governmental efforts to create employment opportunities as the most important method. Although the participants felt the services they provided were effective at the individual and family level, they thought such services were extremely insufficient in terms of poverty reduction on a macro scale. The findings were discussed within the framework of the changing nature of poverty and the recent agenda on poverty reduction in Turkey. Future research based upon larger samples from different parties in the field of social assistance is needed to fully determine the positions taken by the agents.     

Mediator role of intergroup anxiety in relationship between the social contact,intercultural sensitivity and attitudes towards Syrians among Turkish local society

Turkey is the country with the highest Syrian refugee population hosted in the world. Social acceptance of immigrants by the local community is as important as the social cohesion of immigrants regarding the social integration process. The aim of the current study was to examine the role of social contact, intercultural sensitivity, intergroup anxiety, gender, age, education, abroad experience and city on attitudes of Turkish local society towards Syrians. In this regard, data were collected from 207 local community members living in Ankara and Adana provinces of Turkey. According to the analysis, qualitative social contact, intercultural sensitivity and intergroup anxiety predicted the attitudes of the local community towards Syrians. In addition, intergroup anxiety had a mediating role between qualitative social contact, intercultural sensitivity and attitudes towards Syrians. When close social contact and intercultural sensitivity of Turkish local society increase, intergroup anxiety decreases and it increases positive attitudes towards Syrians. Lastly, while there was no gender difference in attitude towards Syrians, females were higher in intercultural sensitivity than males.