基于认知无线电的脉冲陷波UWB窄带干扰抑制

提出了一种基于认知无线电的自适应超宽带（UWB）窄带干扰抑制方法。为了使UWB对变化的 干扰环境具有自适应调节能力,引入了认知无线电技术。通过频谱感知和认知引擎技术提取 窄带干扰频谱特征作为陷波器的设计依据。以高斯脉冲为例,对陷波器的陷波性能进行检验 。最后,就陷波前、后脉冲的通信性能进行比较。仿真结果表明：认知陷波脉冲具有良 好的窄带干扰抑制能力,能够自适应的随着感知结果而动态地规避授权用户,从而实现UWB 系 统与其它通信系统的共存,且此方法不需要在整个频段范围内降低UWB脉冲功率,实现简单 灵活,为提高UWB脉冲发射功率、增大UWB系统的通信距离提供了一种可行的方案。     

新时代中国国际政治经济学研究:问题与方向

国际形势的迅速变化为国际政治经济学研究提供了更为广阔的研究视野,但面对复杂多变的世界经济和政治形势,单纯的经济学研究往往无法解释现实,经济学、政治学以及社会学等诸多学科间的分立与隔绝状态不利于国际政治经济学的深入发展.中国的国际政治经济学研究需要关注五个方面的问题:第一,打破经济学尤其是国际经济学研究的专业壁垒;第二,...     

中国农村减贫成效测度、分解及影响因素研究——基于分布动态学框架的CFPS数据分析

测算农村减贫成效并考察减贫成效的影响因素对我国打赢"脱贫攻坚战"具有重要的现实意义。本文基于覆盖我国东、中、西和东北四大地区的CFPS调查数据,在Quah(1997)的分布动态学(Distribution dynamics)基础上构建了完整的减贫成效分析框架。首先测算出各地区农村家庭贫困内部状态的Markov转移概率矩阵,并在此基础上构建了可分解的绝对、相对减贫指数,以综合考察各地区的农村减贫成效,随后本文通过首次构造的"条件Markov模型"进一步考察了减贫成效的影响因素。研究结果发现:(1)样本考察期内,我国各地区的农村贫困状况随着时间的积累逐渐变好,贫困发生率均有所下降;(2)减贫过程中仍存在着脱贫又返贫的现象,农村家庭的深度贫困固化问题比轻度贫困问题更加严重,意味着扶贫开发工作正式进入攻坚时期,扶贫难度加大;(3)家庭成年成员特征、家庭特征以及收入类型对农村减贫成效的影响显著性情况存在着时段和区域的异质性。其中,家庭成年成员受教育水平、家庭中是否有成员从事有薪酬的农业劳动、工资性和营业性收入对家庭的贫困状态变动具有更显著的影响。基于此,政府应贯彻落实精准扶贫,将扶贫重点放在中西部地区和处于深度贫困的家庭,另外应再调整和倾斜扶贫资源与扶贫政策,将提高农民受教育水平、增加非农业就业机会作为主要减贫途径,将促进农村工资性和营业性收入增长作为主要的政策倾斜方向。     

中国农村特色扶贫开发道路的制度分析：基于产权的视角

研究目标：借鉴马克思及西方产权理论主要思想,研究揭示中国农村特色扶贫开发道路的制度选择及经验。研究方法：基于产权理论对经济事实进行逻辑推演,并采用1978~2012年中国农村统计数据进行检验。研究发现：中国农村特色扶贫开发道路主要体现在农村资源（土地和人力）的产权制度改革上,由此形成的资源产权激励效应和正向扩散效应,正是中国农村人口发生大规模减贫的最重要原因及主要经验,并构成了中国特色社会主义制度的一部分。研究创新：本文基于产权理论的研究为减贫提供一个新的微观制度视角解释。研究价值：总结提炼中国农村特色扶贫开发道路的一般性理论经验,对今后减贫事业推进具有借鉴意义。     

Local poverty reduction in Chile and Mexico: The role of food manufacturing growth

This paper analyzes the relationship between local poverty and food manufacturing growth in Chile and Mexico using propensity score matching, differences in differences and spatial econometrics methods. We focus on food manufacturing as a sector with a number of characteristics that make it potentially pro-poor, and whose incentives for spatial distribution may either strengthen or dampen its poverty reduction potential. The overall results indicate growth in food manufacturing employment contributes to local poverty reduction.     

圈闭勘探开发综合评价决策方法及其应用

圈闭勘探开发是一项高投资、高技术、高风险的工作。许多评价因素的不确定性给决策者带来诸多不便,造成了对圈闭含油气性及其优劣程度判断的模糊映象。而模糊数学综合评判法可以把这些模糊映象用数学方法处理,从而可对圈闭含油气性及其优劣程度进行定量分析评价     

Matching food security and malnutrition indicators: evidence from Southeast Asia

This article aims to understand the relation between household food security and individual undernutrition. The multitude of indicators available raises the question which aspects of food security are captured by the respective indicator. In our analysis, we first assess the relation between the dimensions of food security and households’ socioeconomic characteristics. Second, we examine whether household indicators detect undernutrition in children. Finally, we investigate the role of individual‐specific characteristics for child undernutrition. The analysis is based on a novel data set of 1,200 rural households from Cambodia and Lao PDR, which combines household‐ and individual‐level data. We capture household food security by three indicators including a dietary diversity score, a consumption behavior measure, and an experiential measure. Individual nutrition status is measured via anthropometric indicators. Our results show that different household‐level indicators capture fundamentally different aspects of food security. Moreover, household food security fails to explain stunting for children under five. Dietary diversity indicators, however, explain underweight in children to a small extent. We call for more research on intrahousehold allocation of food and stress the implications of our research for the design and targeting of food and nutrition support programs.     

Asset‐based poverty transition and persistence in rural China

This article tests empirically for transition and persistence of poverty in rural China based on the theory of asset‐based poverty traps. It proposes an analytical framework mitigating the problem of endogenous switching between accumulation regimes and disentangling the true state‐dependence of poverty. Specifically, a dynamic asset threshold separating households into downward and upward mobility regimes is identified after taking households’ unobserved characteristics and observed regime‐differentiated accumulation strategies into account. The static analysis identifies causality running from settling into a downward mobility regime to the probability of poverty measured by consumption. Furthermore, allowing for endogenous initial poverty status, the dynamic analysis finds strong true state‐dependence in poverty. Households with the same characteristics are nearly twice as likely to be poor as if they had not previously switched to the accumulation regime. Assets below the dynamic threshold serve as a conduit through which poverty propagates itself. Factors that help to break this vicious circle are identified.     

解决能力贫困是青海新农村建设的切入点

新农村建设是一项惠及亿万农民的世纪工程,其建设的长期性、艰巨性和复杂性,是由我国农村人口基数大、收入水平低、发展不平衡决定的.青海省作为西部经济欠发达省份的典型代表,新农村建设与经济发达的地区的新农村建设既不在一个起点上,也不可能达到同样的水平.青海省农村贫困的根源不是收入或消费的匮乏,而是由于教育、社会保障、健康和机会等方面的贫困而导致的“能力贫困“,新农村建设的切入点就是尽快解决农民的能力贫困问题.