中沙关系回顾与展望

中国和沙特政治制度不同,但两国发展积极友好的关系没有障碍。目前,沙特是中国在西亚和非洲最大的贸易伙伴,两国经贸合作前景广阔。同时,中沙双方均奉行独立自主的外交政策,拥有良好的政治关系,未来在区域组织和联合国等国际舞台上将有更广泛的合作领域。     

The purpose in life and academic behaviour of problem students in Bangladesh

This study was conducted with a group of 30 problem students who have been identified as irregular in class attendence, non-attentive to class lectures, creating disturbances in the class, etc. The problem students were compared with a group of equal number of normal students with respect to a Purpose in Life (PIL) scale. It was found that the problem students had lower scores (M=59.87, SD=18.09) as compared to those of normals (M=87.93, SD=0.68). These scores differed significantly (t=7.230). From this study it was concluded that the problem students demonstrated such activities due to a lack of purpose in their lives, although it was granted that some causality probably runs in both directions. It is hypothesised that counseling may be helpful in order to improve such behaviour.     

A New Generalized Exponential Geometric Distribution

In this article, another version of the generalized exponential geometric distribution different to that of Silva et al. (2010 Silva , R. B. , Barreto-Souza , W. , Cordeiro , G. M. ( 2010 ). A new distribution with decreasing, increasing and upside-down bathtub failure rate. Computat. Statist. Data Anal. 54: 935–944 . [Google Scholar]) is proposed. This new three-parameter lifetime distribution with decreasing, increasing, and bathtub failure rate function is created by compounding the generalized exponential distribution of Gupta and Kundu (1999 Gupta , R. D. , Kundu , D. ( 1999 ). Generalized exponential distributions . Austral. NZ J. Statist. 41 ( 2 ): 173 – 188 .[Crossref], [Web of Science ®] , [Google Scholar]) with a geometric distribution. Some basic distributional properties, moment-generating function, rth moment, and Rényi entropy of the new distribution are studied. The model parameters are estimated by the maximum likelihood method and the asymptotic distribution of estimators is discussed. Finally, an application of the new distribution is illustrated using the two real data sets.     

Selecting a Good Stochastic System for the Large Number of Alternatives

In this article, we present the problem of selecting a good stochastic system with high probability and minimum total simulation cost when the number of alternatives is very large. We propose a sequential approach that starts with the Ordinal Optimization procedure to select a subset that overlaps with the set of the actual best m% systems with high probability. Then we use Optimal Computing Budget Allocation to allocate the available computing budget in a way that maximizes the Probability of Correct Selection. This is followed by a Subset Selection procedure to get a smaller subset that contains the best system among the subset that is selected before. Finally, the Indifference-Zone procedure is used to select the best system among the survivors in the previous stage. The numerical test involved with all these procedures shows the results for selecting a good stochastic system with high probability and a minimum number of simulation samples, when the number of alternatives is large. The results also show that the proposed approach is able to identify a good system in a very short simulation time.     

An empirical study of the type I error rate and power for some selected normal-theory and nonparametric tests of the independence of two sets of variables

Normal-theory tests of the hypothesis of no relationship among two sets of variables require assumptions of independence, hamoscedasticity, and normality. If, however, the assumption of normality is not tenable, there are few guidelines for properly using these tests. Historically, the lack of a comprehensive hypothesis-testing framework in the nonparametric case has provided few alternatives to normal-theory procedures. Fortunately, this situation has changed with the introduction of nonparametric, general linear model-based tests that can be used with existing computing packages. Multivariate-nonparametric tests due to Puri and Sen (1969, 1971, 1985) and Conover and Iman (1981) are outlined, and the results of a simulation study of the performance of three nonparametric and one normal-theory test of the hypothesis of no relationship among two sets of variables are presented. These results suggest that multivariate-nonparametric tests should be considered for a variety of data conditions. especially heavy-tailed and badly skewed data for small samples and a large number of variates.     

Trends in cardiovascular diseases and associated risks in sub-Saharan Africa: a review of the evidence for Ghana,Nigeria, South Africa,Sudan and Tanzania

Background: Sub-Saharan Africa (SSA) countries are facing an epidemiological shift from infectious disease to chronic diseases, such as cardiovascular diseases (CVDs). CVDs incidence in SSA are frequently attributed to the prevalence of hypertension, diabetes, and overweight/obesity. Nevertheless, some researchers contend that CVDs are not a priority public health problem in SSA.

Method: This paper systematically reviews the evidence on CVDs and their relation with hypertension, diabetes mellitus and obesity/overweight in Ghana, Nigeria, South Africa, Sudan and Tanzania. The publication’s content was analyzed qualitatively using the directed content analysis method and the results were presented in a tabular format.

Result: The paper illustrates the rising prevalence of CVDs as well as the three related risk conditions in the selected SSA countries.

Conclusion: The review indicates a poor health system response to the increasing risk of CVDs in SSA. The conditions and major drivers that contribute to this underlying increasing trend need to be further studied.     

A new double sampling control chart for monitoring process mean using auxiliary information

Statistical quality control charts have been widely accepted as a potentially powerful process monitoring tool because of their excellent speed in tracking shifts in the underlying process parameter(s). In recent studies, auxiliary-information-based (AIB) control charts have shown superior run length performances than those constructed without using it. In this paper, a new double sampling (DS) control chart is constructed whose plotting-statistics requires information on the study variable and on any correlated auxiliary variable for efficiently monitoring the process mean, namely AIB DS chart. The AIB DS chart also encompasses the classical DS chart. We discuss in detail the construction, optimal design, run length profiles, and the performance evaluations of the proposed chart. It turns out that the AIB DS chart performs uniformly better than the DS chart when detecting different kinds of shifts in the process mean. It is also more sensitive than the classical synthetic and AIB synthetic charts when detecting a particular shift in the process mean. Moreover, with some realistic beliefs, the proposed chart outperforms the exponentially weighted moving average chart. An illustrative example is also presented to explain the working and implementation of the proposed chart.     

Maternal,prenatal and traditional practice factors associated with perinatal mortality in Yemen

Background

Perinatal mortality remains a major international problem responsible for nearly six million stillbirths and neonatal deaths.

Effects of Macroeconomic Uncertainty on Investment and Economic Growth: Evidence from Pakistan

The relationship between macroeconomic uncertainty, investment and economic growth is an empirical issue in developing countries. This paper investigates the effects of macroeconomic uncertainty on investment and economic growth in Pakistan for the period 1975–2008 by using the accelerator model of investment and endogenous growth model. The conditional variances, directly estimated through the Generalized Autoregressive Conditional Heteroscedasticity (GARCH) model is utilized for erecting the uncertainty variables related to fiscal policy, openness and foreign capital inflows. The results clearly indicate that the macroeconomic uncertainty have significant negative effects on investment and per capita income of Pakistan. We conclude that a reduction in macroeconomic uncertainty through appropriate fiscal and monetary policy, stability in capital inflows and improved trade performance could result in high investment and sustainable economic growth in the country.