Analysis of censored data

Analyzing events over time is often complicated by incomplete, or censored, observations. Special non-parametric statistical methods were developed to overcome difficulties in summarizing and comparing censored data. Life-table (actuarial) method and Kaplan-Meier method are described with an explanation of survival curves. For the didactic purpose authors prepared a workbook based on most widely used Kaplan-Meier method. It should help the reader understand how Kaplan-Meier method is conceptualized and how it can be used to obtain statistics and survival curves needed to completely describe a sample of patients. Log-rank test and hazard ratio are also discussed.     

Approximation based on orthogonal and almost orthogonal functions

In this paper, we define a class of almost orthogonal rational functions of Legendre type in a new manner. Relations of these functions with classical exponentional functions orthogonal over interval (0, ∞), as well as classical polynomials orthogonal over (0, 1) are explained. Defining relations of these functions can be used for designing almost orthogonal filters. These filters are generators of orthogonal signals and can be successfully applied in finding the best signal approximation in the sense of the mean square error. The filters orthogonal property enables building of physical (in this case electrical) models of dynamical systems (the sources of signals to be approximated) either with less components for the same model accuracy or higher accuracy for the same number of components than the other known models. New filters represent further improvement of previously designed filters, by the same authors, in the sense of simplicity, higher accuracy, lesser approximation time and even a possibility to approximate signals generated by systems with built-in imperfections. Series of experiments were performed to analyze the dependence of approximation accuracy and the number of filters sections.     

Extending the understanding of mobile banking adoption: When UTAUT meets TTF and ITM

Mobile banking (mBanking) enables customers to carry out their banking tasks via mobile devices. We advance the extant body of knowledge about mBanking adoption by proposing a model for understanding the importance and relationship between the user perception of mBanking, initial trust in mBanking services, and the fit between the technology and mBanking task characteristics. We synergistically combine the strengths of three IS theories – task technology fit (TTF) model, unified theory of acceptance and usage of technology (UTAUT), and initial trust model (ITM). The model was tested in a study conducted in Portugal, one of the European Union (EU) countries with the highest mobile phone adoption. Based on the sample of 194 individuals we applied partial least squares (PLS) to test the conceptual model propose. The path significance levels were estimated using the bootstrapping method (500 resamples). The study found that facilitating conditions and behavioral intentions directly influence mBanking adoption. Initial trust, performance expectancy, technology characteristics, and task technology fit have total effect on behavioral intention. The paper offers valuable insights to decision-makers involved in the implementation and deployment of mBanking services. For researchers, the paper highlights the usefulness of integrating TTF, UTAUT and ITM in the development of a decision support framework to study the adoption of new technologies.     

THE INTERNATIONALIZATION OF HIGHER EDUCATION: A POINT OF VIEW FROM A DEVELOPING COUNTRY

This article takes a close analytical look at the internationalization of higher education, asking penetrating questions with regard to its basis, its forms, and its results. The author is particularly concerned with problems of asymmetry with regard to the educational links, particularly at higher education level, between the developed western democracies and the developing countries. Going beyond the question of brain drain, the article probes the problem of the alienation of third world academics trained in the higher education institutions of developed countries. While on the balance the author praises the results of the internationalization of higher education and, at any rate, recognizes that it is here to stay, he cautions all those involved in it be aware of who in fact gains and who loses as a result of it.     

Das Bildungssystem der Sozialistischen Föderativen Republik Jugoslawien (SFRJ)

Ohne Zusammenfassung     

Development of Math Attitudes and Math Self-Concepts: Gender Differences,Implicit–Explicit Dissociations,and Relations to Math Achievement

Three hundred and ninety-one children (195 girls; M_age = 9.56 years) attending Grades 1 and 5 completed implicit and explicit measures of math attitudes and math self-concepts. Math grades were obtained. Multilevel analyses showed that first-grade girls held a strong negative implicit attitude about math, despite no gender differences in math grades or self-reported (explicit) positivity about math. The explicit measures significantly predicted math grades, and implicit attitudes accounted for additional variance in boys. The contrast between the implicit (negativity for girls) and explicit (positivity for girls and boys) effects suggest implicit–explicit dissociations in children, which have also been observed in adults. Early-emerging implicit attitudes may be a foundation for the later development of explicit attitudes and beliefs about math.     

Traditional vs. innovative uses of computers among mathematics pre-service teachers in Serbia

This study examined pre-service teachers’ intentions to use computers in traditional and innovative teaching practices in primary mathematics classrooms. It extended the technology acceptance model (TAM) by adding as external variables pre-service teachers’ experience with computers and their technological pedagogical content knowledge (TPCK). Data collected from 226 participants revealed that the proposed model had a good fit for both traditional and innovative uses of computers. Structural equation modelling suggested that the established TAM variables, together with TPCK and experience, were significant determinants of pre-service teachers’ intentions to use computers in teaching mathematics at both levels. The most dominant determinant of behavioural intention was TPCK, followed by attitude. The proposed model explained 22.7% of the variance in the use of computers in traditional teaching practices and 27.6% of the variance in the use of computers in innovative teaching practices. The implications for mathematics teaching are discussed in the final section.     

Social inequalities in access to higher education in Croatia: five decades of resilient findings

This article provides a panoramic view of research findings on social inequalities in access to higher education in Croatia since the 1960s, guided by the question of what has changed in the findings. Our review shows that there is stark continuity over the last five decades: students from better educated family backgrounds tend to be overrepresented in higher education; students from better educated and white-collar family backgrounds are more likely to enrol in academic as opposed to professional study courses; students at one Croatian university in particular stand out in terms of their more privileged social background; and medicine seems to be the prime academic field for observing social reproduction. We note that these persistent findings run parallel to a dramatically changing political, economic and social context in Croatia, including transformations in the 1990s resulting from social ownership of the means of production to widespread private ownership, as well as transformations from a one-party political system to the establishment of a multi-party political system. The article maps possible theoretical explanations for the resilience of social inequalities in access to higher education in the context of dynamic times. It also questions the role of educational policies in this process.