准格尔旗退耕还林工程影响下农户农牧系统能值变化

退耕还林工程对农户生产生活影响引起广泛关注,根据2011年准格尔旗农户调查数据,运用能值分析的方法,探讨了4户典型农户退耕还林工程前后农牧系统能值变化。研究表明:在退耕还林工程与农户耦合作用下,农户耕作面积普遍减少,大部分农户的放牧行为得到有效控制;农户的农牧业生产对自然资源投入的依赖程度减少,而化肥、农药、机械等工业辅助能明显增加;农户农牧系统转变的潜在问题是农牧产品竞争力下降、环境负载率增加等。     

Modeling the growth and policy implications of Global System for Mobile Telecommunication （GSM） in Nigeria

This paper investigated the growth and policy implications of Global System for Mobile Communication in Nigeria. Stochastic economic modeling was used to analyze Nigeria＇s time series data. The models were adjudged reliable before they were used. The components of the model were defined and a prior expectation of the relationship among the variables explained for the purpose of giving the reviewers and users a deep insight into the phenomenon under study. The secondary data used for the study were processed using the E-View for windows electronic packages. The outcome of the empirical and stochastic investigations shows that Global System for Mobile Communication has a positive relationship with output growth in Nigeria. The impact is of a higher magnitude. The usage of Global System for Mobile Telecommunication led to 17 percent rise in the output growth. The findings suggest the need for the Nigerian Communication Commission （NCC） and the federal government of Nigeria to expand tele-density and directly make telephone communications cheap and accessible. To achieve this goal, more licenses should be given to GSM operators in order to allow for healthy competition among them. This will lead to improved quality of services, quality of product and consequently sustain the growth and development of the country.