A comparison of different procedures for principal component analysis in the presence of outliers

Principal component analysis (PCA) is a popular technique that is useful for dimensionality reduction but it is affected by the presence of outliers. The outlier sensitivity of classical PCA (CPCA) has caused the development of new approaches. Effects of using estimates obtained by expectation–maximization – EM and multiple imputation – MI instead of outliers were examined on the artificial and a real data set. Furthermore, robust PCA based on minimum covariance determinant (MCD), PCA based on estimates obtained by EM instead of outliers and PCA based on estimates obtained by MI instead of outliers were compared with the results of CPCA. In this study, we tried to show the effects of using estimates obtained by MI and EM instead of outliers, depending on the ratio of outliers in data set. Finally, when the ratio of outliers exceeds 20%, we suggest the use of estimates obtained by MI and EM instead of outliers as an alternative approach.     

A Monte Carlo simulation study on partially adaptive estimators of linear regression models

This paper presents a comprehensive comparison of well-known partially adaptive estimators (PAEs) in terms of efficiency in estimating regression parameters. The aim is to identify the best estimators of regression parameters when error terms follow from normal, Laplace, Student's t, normal mixture, lognormal and gamma distribution via the Monte Carlo simulation. In the results of the simulation, efficient PAEs are determined in the case of symmetric leptokurtic and skewed leptokurtic regression error data. Additionally, these estimators are also compared in terms of regression applications. Regarding these applications, using certain standard error estimators, it is shown that PAEs can reduce the standard error of the slope parameter estimate relative to ordinary least squares.     

Profust reliability of linear and circular type F and G systems having two failure criteria under Markov dependency

In this study, the profust reliabilities of (n, f, k): F(G) and < n, f, k > : F(G) systems for Markov dependent components are investigated. Having two failure criteria are the common features of these four systems. The usage of both fuzzy approach and two failure criteria in the same system provides us more realistic approach to evaluate the reliability of more complex systems. The component configurations are examined for both linear and circular sequences and the working principle of systems are studied for both F and G systems. Under all these assumptions, the profust reliabilities of (n, f, k): F(G) and < n, f, k > : F(G) systems are obtained using the distribution of run statistics. Also a new membership function different from the linear membership function which is generally used in the literature is proposed. Some numerical results which allow the comparison of the systems from various perspectives and various figures for both linear and circular type systems are presented. Some special cases (between Markov – iid assumption, conventional – profust reliability) are also considered.     

Political participation beyond borders: a comparative analysis of Turkish youth living in home country,Germany and Belgium

Drawing on data from a large-scale international study [PIDOP – Processes Influencing Democratic Ownership and Participation. 2009–2012. Accessed August 10. http://www.fahs.surrey.ac.uk/pidop/index.htm], the present research examined psychological and demographic factors related to civic and political participation among adolescents and young adults (from 16 to 26 years of age) with a Turkish origin and residing in Belgium (n?=?153), Germany (n?=?204) and Turkey (n?=?253). MANCOVA and one-way ANOVA were employed to address how types of civic, direct and online participation differ by socio-demographic variables. The results indicate that citizenship status was not related with the types of participation, while age, gender and country were significantly related with the type of participation in various degrees. Interaction between all the variables showed that older (20–26), foreign national, male Turkish German sample is significantly more involved in civic participation activities. Results are discussed in light of the naturalization processes of migrant groups abroad and extensive religious involvement of Turkish German sample.     

An Overview of a Hospital-Based Child Advocacy Center’s Experience from Turkey

The purpose of the present study was to investigate sociodemographic variables, features of sexual abuse (SA), and first psychiatric evaluation results of abused children, and to analyze the relation of the psychiatric evaluation results to the children’s age and gender, type and duration of abuse, abuser–child relationship, and marital status of the children’s parents, at one of the most experienced Child Advocacy Centers (CACs) in Turkey. All data were obtained from reports prepared by child and adolescent psychiatrists. The sample of this study consists of 436 child sexual abuse (CSA) cases who admitted ?zmir CAC between April 2014 and November 2015. The statistical analyses yielded significant relations between psychiatric symptoms and chronic abuse, the gender of the children, and type of abuse. Suicidal ideation and behaviors due to sexual abuse (SA) were also examined. According to our results, it is fair to say that children exposed to SA benefit from immediate psychiatric help because of their vulnerability for psychiatric disorders due to abuse. In this context, CACs are very important multidisciplinary establishments to determine children’s multiple needs to ease their trauma with collaborative teamwork. Psychiatric evaluation should be part of this multidisciplinary context.     

Socio-Economic Disparities in the Development of the Romania’s Border Areas

The Romanian border areas include 898 Local Administrative Units 2 (LAU2), of which 88 are urban and 810 rural. Romania has borderline with the following countries: Bulgaria, Republic of Moldova, Serbia, Ukraine, Hungary, of which 63.5 % is Non-European Union boundary. According to the population structure, 51.6 % of the total population is urban and the rest of 48.4 % is rural. In order to assess the socio-economic territorial disparities in the development of the urban space of Romanian border areas, several research stages were carried out: selecting 22 relevant statistical indicators, analyzing territorial disparities, standardizing the absolute values of the indicators, grouping the elementary indicators by 7 multiple indicator clusters (secondary indexes) in order to reflect the main socio-economic development aspects: (1) housing, (2) public utilities infrastructure and green areas, (3) health, (4) labour market, (5) demography, (6) education and (7) local economy. Finally, the authors were able to compute secondary indexes and the Index of Socio-Economic Development as Hull Score with a mean of 50 and a standard deviation of 14, revealing the levels of socio-economic development (high, average and low). Generally, the outcomes of the current study are in line with Romania’s complex socio-economic disparities, rooted in the historic background of the country. Spatially, the economic development follows a West–East direction, the less developed areas being concentrated in the Eastern and Southern part of the country.     

Wage Inequality and Wage Mobility in Turkey

Social Indicators Research - This paper investigates wage inequality and wage mobility in Turkey using the surveys on income and living conditions. Providing the first evidence on wage mobility for...     

Uniform trade rules for uncleared markets

We analyze markets in which the price of a traded commodity is such that the supply and the demand are unequal. Under standard assumptions, the agents then have single peaked preferences on their consumption or production choices. For such markets, we propose a class of Uniform trade rules each of which determines the volume of trade as the median of total demand, total supply, and an exogenous constant. Then these rules allocate this volume “uniformly” on either side of the market. We evaluate these “trade rules” on the basis of some standard axioms in the literature. We show that they uniquely satisfy Pareto optimality, strategy proofness, no-envy, and an informational simplicity axiom that we introduce. We also analyze the implications of anonymity, renegotiation proofness, and voluntary trade on this domain.     

Economic Crisis and Marital Problems in Turkey: Testing the Family Stress Model

This paper applied the family stress model to the case of Turkey in the wake of the 2001 economic crisis. Using structural equation modeling and a nationally representative urban sample of 711 married women and 490 married men, we tested whether economic hardship and the associated family economic strain on families resulted in greater marital problems. Our results showed a modified family stress model applies to Turkey. In contrast to most previous research, economic strain had a direct effect on marital problems, and the indirect effect of strain, via emotional distress, was only significant for women. The results were interpreted in light of social and cultural factors that condition how economic distress affects marital relations.     

Tracking public relations history in 1960s’ Turkey: The prevalence and reflections of development discourse

This study is based on a historical research, which focuses on the institutionalization of public relations in Turkey during the 1960s, and interprets this process in the frame of planned development discourse. Primary written sources collected from archive research and oral narratives generated from fourteen semi-structured interviews conducted with the pioneers in Turkey are analyzed through categorization and thematization. Findings of the historical research indicated that similar themes and orientations guided public relations practices in public and private sector in this period. Accordingly public relations education provided necessary intellectual background and human resources.