基于到达角误差约束的稳健宽带波束合成算法

针对阵列天线存在系统误差的情况,在Frost结构的基础上提出了一种改进的稳健宽 带波束合成算法。该算法以信号到达角（DOA）误差为约束条件合成期望信号,并把滤波器 优化设计转化为凸优化问题,使用内点迭代法有效解决,进一步使得期望的信号响应具有一 定的波动性,从而使得更多的自由度应用在干扰和噪声的抑制上,达到优化加权制的目的。 仿真结果表明,当系统存在一定的DOA误差、幅相误差和位置误差时,所提出的宽带波束合 成算 法获得的信干噪比（SINR）比worst-case约束算法提高约1～3 dB。     

基于迭代FFT算法的平面稀疏阵列优化方法

提出了一种基于迭代FFT算法的优化方法来实现平面稀疏阵列的峰值旁瓣电平优化 ,并给出了详细的优化步骤。在给定的旁瓣约束条件下,利用阵列因子与阵元激励之间存在 的傅里叶变换关系,对不同的初始随机阵元激励分别进行迭代循环,就可以降低稀疏阵列的 旁瓣电平。在迭代过程中,根据稀疏率将阵元激励按幅度大小置1置0来完成阵列稀疏。仿真 实验证明了该方法的高效性和稳健性。     

国有企业经营者报酬契约模型研究

随着现代企业制度在我国的建立和发展,作为现代公司治理的重要内容和公司长远发展的关键因素,激励约束机制引起了学界的广泛关注。与发达的市场经济下的企业组织相比,由于体制原因和历史遗留问题,国有企业激励约束机制的构建面临着多方面的特殊因素,存在诸多困难。本文主要分析了国有企业委托代理关系的特殊性和复杂性,通过建立国企经营者激励约束的报酬契约模型,为国企激励约束机制的改进提供一个新的思路和方法。     

水资源刚性约束下黄河流域高质量发展研究进展

黄河流域生态保护和高质量发展是重要的国家战略,水资源的刚性约束关系高质量发展成败。通过梳理黄河流域高质量发展的相关研究文献,从概念体系研究、水资源承载力研究、资源约束下的经济增长研究等3个范式切入,分析现有黄河流域高质量发展研究进展与不足。结果显示,现有研究集中高质量发展概念体系构建、水资源承载力与经济增长耦合、资源约束下的经济增长等议题,但尚未有研究阐明水资源刚性约束下高质量发展的机制。在阐释了水资源最大刚性约束作用机制的基础上,提出水资源约束高质量发展、高质量发展提升水资源承载力、统筹安全和发展的水资源约束机制,认为应建立起水资源刚性约束下的自然环境资源和社会经济增长的动态联系,并对可能的研究提出展望。     

Impact of the Sloping Land Conversion Program on rural household income: An integrated estimation

The objective of this study is to identify the pathways of the potential impacts of the Sloping Land Conversion Program (SLCP) on household income and quantify these impacts along the identified pathways. We fulfill this objective by developing an integrated analytic framework and using data collected from Wuqi county of Shaanxi for the period 2004–2010. This integrated analytic framework enables us to formulate a structural equation model for testing hypotheses regarding the direct and indirect impacts of the SLCP. It is found that the direct effect of the SLCP on household income is positive but very small and insignificant, suggesting that retiring cropland has, at least, not reduced income from farming. Moreover, the SLCP has had a much higher and even increasing indirect impact on household income through promoting labor transfer and relaxing liquidity constraints. Overall, the SLCP's total impact on household income ranged from 3% in 2004 to 9% in 2010 excluding the insignificant direct impact. The research and policy implications of our work are discussed.     

Heterogeneous Risk Preferences,Discount Rates and Land Contract Choice in Ethiopia

This paper analyses the role of risk and rate of time preference in the choice of land contracts. The analysis builds on the risk‐sharing and imperfect market explanations of contract choice. Unique data from Ethiopia, which contain land contract information and experimental risk and rate of time preference measures on matched landlord–tenant partners, are employed in the empirical analysis. The results show that landlord and tenant time preferences are significant determinants of contract choice. For landlords (but not tenants), risk preference is also significant, indicating the importance of financial constraints and production risk in the determination of contract choice. The results are of particular relevance to land market policy in Ethiopia, where production is risk‐prone, financial markets are imperfect, and where there is a major need for the development of vibrant land rental markets.     

Incentives for motivated agents under an administrative constraint

Consider an agent who has an expertise in producing a non-marketable good. This good is valued by a single principal, and there is a verifiable measure of the agent’s performance. Crucially, the agent is intrinsically motivated due to ‘warm glow altruism’. In addition, the agent’s budget, which is controlled by the principal, must not be less than the monetary performance-cost faced by the agent. This gives rise to a limited-liability constraint. It also restricts the agent’s ability to under-report costs. In such environment, we determine the link between the agent’s budget and performance. Our results come in contrast to the received solution of the principal-agent problem and to most in the literature on mission-motivated organisations and public services provision.     

Exchange rates and ownership structure of Japanese multinational firms

This paper investigates the determinants of Japanese multinationals’ ownership structures. Unlike most previous studies that neglect the impact of financial constraints on ownership, we add the exchange rate as a measure of wealth and test whether exchange rates affect the ownership share of foreign direct investment projects. After controlling for other variables that affect ownership, we find that exchange rates have a significant effect on the likelihood of wholly owned subsidiaries. We also discuss several other explanations for the link between exchange rates and foreign direct investment and provide evidence that the link stems from capital-market imperfections.     

唐山市农村劳动力资源现状分析及其开发对策

文章在对河北省唐山市2007年农村劳动力资源现状监测调查和分析评价的基础上,总结了唐山市加快农村剩余劳动力资源分流转移的主要做法,分析了农村劳动力资源开发利用制约因素,提出了促进劳动力资源开发利用与分流转移的对策和建议。     

A note on a semiparametric approach to estimating financing constraints in firms

In this paper, we present a novel approach to modeling financing constraints of firms. Specifically, we adopt an approach in which firm-level investment is a nonparametric function of some relevant firm characteristics, cash flow in particular. This enables us to generate firm-year specific measures of cash flow sensitivity of investment. We are therefore able to draw conclusions about financing constraints of individual firms as well as cohorts of firms without having to split our sample on an ad hoc basis. This is a significant improvement over the stylized approach that is based on comparison of point estimates of cash flow sensitivity of investment of the average firm of ad hoc sub-samples of firms. We use firm-level data from India to highlight the advantages of our approach. Our results suggest that the estimates generated by this approach are meaningful from an economic point of view and are consistent with the literature.