A novel approach based on multiple correspondence analysis for monitoring social networks with categorical attributed data

In in most cases, the distribution of communications is unknown and one may summarize social network communications with categorical attributes in a contingency table. Due to the categorical nature of the data and a large number of features, there are many parameters to be considered and estimated in the model. Hence, the accuracy of estimators decreases. To overcome the problem of high dimensionality and unknown communications distribution, multiple correspondence analysis is used to reduce the number of parameters. Then the rescaled data are studied in a Dirichlet model in which the parameters should be estimated. Moreover, two control charts, Hotelling’s T² and multivariate exponentially weighted moving average (MEWMA), are developed to monitor the parameters of the Dirichlet distribution. The performance of the proposed method is evaluated through simulation studies in terms of average run length criterion. Finally, the proposed method is applied to a real case.     

Analysis of covariance under inverse Gaussian model

This paper considers the problem of analysis of covariance (ANCOVA) under the assumption of inverse Gaussian distribution for response variable. We develop the essential methodology for estimating the model parameters via maximum likelihood method. The general form of the maximum likelihood estimator is obtained in color closed form. Adjusted treatment effects and adjusted covariate effects are given, too. We also provide the asymptotic distribution of the proposed estimators. A simulation study and a real world application are also performed to illustrate and evaluate the proposed methodology.     

Testing the equality of two independent regression models

In some situations, for example in agriculture, biology, hydrology, and psychology, researchers wish to determine whether the relationship between response variable and predictor variables differs in two populations. In other words, we are interested in comparing two regression models for two independent datasets. In this work, we will use the parametric and nonparametric methods to establish hypothesis testing for the equality of two independent regression models. Then the simulation study is provided to investigate the performance of the proposed method.     

Stress and Leadership Tendencies of Respondents from Iran: Exploring Similarities and Differences Based on Age and Gender

The leadership tendencies of people are likely to be influenced by their cultural contexts. For example, it is expected that people from high-context cultures are likely to be more focused on relationships. To explore the behavioral tendencies of working adults in the cities of Tehran and Kerman, this pilot study focused on comparing the leadership and stress perceptions of 228 Iranian respondents based on their age and gender. These respondents have a significantly higher score on relationship orientation. On the other side, the younger respondents from Iran had a significantly higher score on the stress overload perception. Practical suggestions for expatriates and implications for future studies are presented.     

Outcomes of parental mental illness on children: a qualitative study from Iran

Children of parents with mental illness are a substantial, yet marginalized group. This study, as part of a more extensive research project, used grounded theory to explore the outcomes of parental mental illness on their children. Seventeen informants were interviewed at a mental hospital in the city of Qazvin, Iran. The participants were selected using purposeful and theoretical sampling. Interviews were analyzed using Strauss and Corbin's method. It was revealed that parental mental illness leads to five major outcomes that involve communication, mental, educational, economic, and extra roles factors. As such, it is suggested that these children should be considered within health care plans and that policy makers, nurses, and other health care providers use these findings for preventive and educational purposes.     

Goodness-of-Fit Tests Based on Correcting Moments of Entropy Estimators

In this article, we consider the entropy estimator introduced by Alizadeh Noughabi and Arghami (2010) and derive the nonparametric distribution function corresponding to our estimator as a piece-wise uniform distribution. We use the results to introduce goodness-of-fit tests for the normal and the exponential distributions. The critical values and powers for some alternatives are obtained by simulation. The powers of the proposed tests under various alternatives are compared with the competitors.     

Hybrid test for the hypothesis of symmetry

In recent years, McWilliams and Tajuddin have proposed new and more powerful non-parametric tests of symmetry for continuous distributions about a known center. In this paper, we propose a simple non-parametric two-stage procedure based on the sign test and a percentile-modified two-sample Wilcoxon test. The small-sample properties of this test, Tajuddin's test, McWilliams' test and a modified runs test of Modarres and Gastwirth are investigated in a Monte Carlo simulation study. The simulations indicate that, for a wide variety of asymmetric alternatives in the lambda family, the hybrid test is more powerful than are existing tests in the literature.     

Effects of Class Positions of Parents on Educational Attainment of Daughters and Sons*

Cet article évalue les effets de l'appartenance de la mère et du père à une classe - déterminée selon la théorie marxiste des classes -sur le niveau d'instruction de leurs enfants, garçons et filles, au Canada. Les données sont tirées d'un échantillon représentatif de Canadiens et de Canadiennes. Les analyses multivariables mon-trent que l'appartenance du père et de la mère à une classe influe sur le niveau d'instruction des enfants des deux sexes. Que le père ou la mère soit issu de la bourgeoisie, de la classe des dirigeants ou de la classe des spécialistes, l'enfant aura un niveau d'instruction plus élevé que celui dont les parents appartiennent à une autre classe. On a toutefois observé que seuls certains effets de l'appartenance à une classe étaient directs; les effets liés à l'appartenance à une classe semblent ne se manifester que partiellement dans les differences de niveau d'instruction des parents, qui sont liées à la classe à laquelle ils appartiennent. Les niveaux d'instruction de la mere et du père influent directement sur le niveau d'instruction des enfants des deux sexes, une fois neutralisés les effets de l'appartenance sociale des parents. De plus, les effets du niveau d'instruction du père et de la mère ont tendance à différer selon le sexe de l'enfant (le niveau d'études de la mère influe davantage sur celui de la fille et à l'inverse celui du père influe davantage sur celui du fils). Toutefois, cette tendance ne se vérifie pas en ce qui concerne les effets de l'appartenance des parents à une classe. Les analyses qui comparent les sous-échantillons d'âges indiquent que la double influence de l'appartenance des parents à une classe et de leur niveau d'instruction a diminué après les années soixante compara-tivement aux années précédentes. Les résultats sont interprétés à la lumière de la théorie du capital culturel. This paper assesses the effects of mothers' and fathers' class positions—measured in terms of Marxist class categories—on the educational attainment of male and female offspring in Canada. Our data are from a national representative sample of Canadians. Multivariate analyses show that, for offspring of both genders, the class positions of fathers and mothers influence educational attainment. Where either parent was a member of the bourgeois, managerial or expert class categories, this meant more education for the offspring than other class backgrounds. Only some proportions of the class effects were direct; the effects of class background appear to partially operate through differences in educational attainment of parents that are associated with parents' class positions. Mothers' and fathers' education levels continue to have comparatively strong positive relationships with educational attainment for offspring of both genders after controls for class categories of parents. Further, the effects of paternal and maternal education tend to be “same-sex directed” (mothers' education levels have stronger effects for daughters than for sons and vice versa for fathers' education). However, a similar pattern does not hold for the effects of parental class positions. Analyses comparing age sub-samples indicate that the influences of both parental class positions and parental education levels upon educational attainment of offspring have decreased in the post-1960 period compared with earlier years. The results are interpreted in terms of the theory of cultural capital.     

Change Point Estimation of Multivariate Linear Profiles Under Linear Drift

In this paper, maximum likelihood estimators (MLE) for both step and linear drift changes in the regression parameters of multivariate linear profiles are developed. Performance of the proposed estimators is compared under linear drift changes in the regression parameters when a combined MEWMA and Chi-square control charts method signals an out-of-control condition. The effect of smoothing parameter of MEWMA control charts, missing data, and multiple drift changes on the performance of the both estimators is also evaluated. The application of the proposed estimators is also investigated thorough a numerical example resulted from a real case.