箱须图在识别统计数据异常值中的作用及R语言实现

从统计图形的角度探讨识别统计数据中的异常值,即箱须图在识别统计数据中的异常值中具有的重要的作用。在R语言的环境下,结合箱须图的程序语言的应用具体实例,说明异常值不能对四分位标准施加影响;而箱线图识别异常值的结果比较客观,在识别异常值方面具有一定的优越性。     

Rethinking the area approach: Immigrants and the labor market in California

A framework that uses a Constant Elasticity of Substitution (CES) production function with skill differentiation and integrated national labor markets has predictions for the employment effect of immigrants at the local level. The employment (rather than wage) response to immigration by skill in a state reveals the production substitutability-complementarity between native and immigrant labor. This, in turn, reveals the degree to which immigrants stimulate or depress the demand for native labor. To estimate this elasticity, I use a novel instrument based on demographic characteristics of total Central American migrants or of the Mexican Population to predict immigration by skill level within California. Looking at immigration to California between 1960 and 2005 these estimates support the assumption of a nationally integrated labor market by skill and they support the hypothesis that natives and immigrants in the same education-experience group are not perfectly substitutable. This explains the counter-intuitive fact that there is a zero correlation between immigration and wage and employment outcomes of natives in the state.     

矿业城市循环经济技术支撑体系研究

矿业城市是随着矿产资源的开发而形成和发展起来的,矿业城市为我国持续快速经济增长提供大量物质保障的同时,其自身的资源、环境及发展问题也更加突出。着眼于矿业城市的持续发展,论文分析了矿业城市资源、环境问题的技术选择导向,构建了矿业城市循环经济的＂5R＂原则及相应的技术支撑体系,并对该体系的具体内容及实现途径进行了探讨。研究认为：①从技术角度而言,资源、环境外部性导向和追求劳动生产率的技术选择,是矿业城市资源、环境和发展问题的主要原因;②基于资源产业运行中对区域资源、环境的强干扰特征,矿业城市循环经济系统应包含开源化、减量化、再使用、再循环、再恢复五个方面（＂5R）＂原则,产业提升过程中＂5R＂原则不断耦合与互动,实现矿业城市的持续发展;③围绕矿业城市循环经济系统的运行,应建立包括＂5R＂及产业提升六个方面的技术支撑体系;④技术支撑体系的实现,需要企业、产业链、生态园区、产业集群体、行业协会及矿业城市等不同层次在技术引进、技术创新、技术整合等方面的协调运行。     

GMSK调制器电路设计与FPGA实现

分析了GMSK调制原理,设计了GMSK调制器的一种全数字实现电路。该电路采用查表 法实现高斯滤波功能,采用CORDIC算法完成正交调制信号输出,具有电路规模小、精度可调 、应用灵活等特点。该电路通过了FPGA验证并成功应用于TETRA集群通信系统。     

融资约束、代理成本与企业研发效率——基于中国工业上市公司的实证研究

本文以2004~2012年我国工业上市公司中已披露研发费用的企业为样本,采用随机前沿分析方法研究融资约束和代理成本对企业研发效率的影响,主要得出以下结论:融资约束对企业研发效率有显著的正向影响;而代理成本与企业研发效率之间呈现出显著的负向关系;企业的融资约束可以缓解代理成本对企业研发效率的负向作用。此外,本文的实证结果还表明,国有控股企业的研发效率低于非国有控股企业的研发效率,而且企业研发并没有随着研发强度的提高而产生规模效应。     

区域R&D活动投入结构差异的比较研究

R&D活动是拥有自主知识产权的科技活动,其投入状况影响着区域科技创新的发展。科学、合理的R&D投入结构是提升区域科技创新的有效路径。本文以国家统计局公布的《第二次R&D资源清查主要数据公报》为依据,从R&D活动类型角度建立了R&D投入因子模型,根据因子得分将各省市的R&D投入分为高,中,低投入区,分析了不同的投入区里省市R&D活动在投入结构上的差异及利弊,并提出相关建议,为省市自治区科技创新投入的政策完善,缩小区域间科技创新活动的差距提供参考依据。     

企业家精神、寻租活动与企业研发投入

文章通过一个最优化数理模型刻画了企业家精神与企业RD投入间的关系,并认为随着寻租力度的增大,企业家精神对企业研发投入促进作用会逐步减弱,1998-2012年的中国省际面板数据验证了这一结论。为此,政府应加强腐败治理,增大企业家寻租风险,从而降低寻租的期望收益,并更多地让位于市场配置资源,引导形成合理的相对报酬结构,促进企业家更多地投身于企业的生产性和RD活动中。     

Regional technical efficiency and technology gaps in rural China: evidence from CHIP surveys

This paper uses household-level datasets called Chinese Household Income Project (CHIP) surveys to investigate the regional technical efficiency, technology gap, and their determinants in rural China. A metafrontier production function approach is employed to fit the values of the technical efficiency and the technology gap ratio of rural households in six regions of China. The findings indicate that the technical efficiency improved remarkably from 1988 to 2002, but the technology gap ratio among regions changed slightly in the same period. The findings also show a negative relationship between the technology gap ratio and the regional technical efficiency for all regions except the northwest that has the lowest value of both the technical efficiency and the technology gap ratio. Next, the Tobit model is employed to discern the sources of efficiency and technology gaps. The results show that quality of agricultural labor, agricultural infrastructure, natural conditions, and farmer's political status have significant effects on farms' technical efficiency and technology gap ratio.     

分形市场中的汇率协整关系

本文将混沌与分形运用到汇率研究中,运用R/S方法研究了外汇收益率的长记忆性,并将传统的协整理论推广到广义的分数维协整,研究了时间序列之间的长期均衡关系,并以外汇市场中的欧元和新加坡元兑美元的汇率为例进行了实证分析,指出这两种货币收益率服从分形分布,具有相同的分整阶数且二者存在分数维协整关系。     

Welfare consequences of water supply alternatives in rural Tunisia

Many economic studies have addressed the issue of inefficiency of public water supply in rural areas and the potential for improved service by private companies. Many of these analyses focused on identifying either willingness to pay or comparing average service costs and prices paid by customers. This paper performs a welfare analysis of two water supply systems—public and self owned—in rural Tunisia. The paper calculates consumer and producer surplus and compares the performance of the two systems from a social point of view. Results suggest that both systems are inefficient, mainly because of a production level that is low compared with production capacity.