具有控制时滞的滞后型Lurie控制系统的绝对稳定性判据

通过构造适当的Lyapunov泛函,结合不等式分析的技巧,得到了具有控制时滞的滞后型Lurie控制系统绝对稳定的时滞无关和时滞相关条件,这些条件用线性矩阵不等式表示,易于验证且保守性低,最后通过实例验证了所得结果的有效性.     

高阶非线性时滞差分系统渐近常数解的存在性

利用Schauder-Tychonoff不动点定理,研究了一类高阶时滞差分系统,获得了一组渐近常数解存在的充分性条件.     

浅析农村土地流转对劳动力市场的要求

农村土地流转必然会造成剩余农村劳动力向非农领域转移,现有的城乡分割的劳动力市场却无法促进转移,因而建立一个统一、开放、竞争有序的城乡一体化的劳动力市场就成为一种基本诉求。构建城乡一体化的劳动力市场,要抓好城乡二元户籍制度、义务教育与农民后续教育制度、劳动力市场制度的改革,规范劳动力让渡的中介环节。     

Politics and performance: the implications of emerging governance arrangements for urban management approaches and information systems

Challenges to traditional public sector approaches to urban government have had an impact on various aspects of governance and management, including political arrangements, decision making processes, ways of ensuring accountability, the allocation of roles and responsibilities between public sector agencies and other potential service providers and between different levels of government, and the mobilisation and allocation of financial resources for urban development. These are discussed, drawing in particular on recent research on urban poverty and governance in ten cities in the South. The changing approaches to urban government and management have been accompanied by attempts to define criteria by which urban governance arrangements and performance can be assessed, which are summarised and critically evaluated. Finally, the potential value of a particular set of tools (GIS) for emerging approaches to urban governance is assessed. Their potential for improving the information available to all governance actors is recognised. However, because of their cost and technological and managerial demands, as well as the limited effectiveness of spatial planning and inequalities in access to information, plans for their use must be financially, institutionally and politically realistic.     

What's Driving Brazil‐Japan Migration? The Making and Remaking of the Brazilian Niche in Japan

Abstract: Since the late 1980s the Brazilian population in Japan has steadily increased, despite the long‐term recession in the late 1990s. In this paper we will examine the mechanism of the constant increase of Brazilians in Japan, focusing on the institutional context of their incorporation into the Japanese labor market. On the demand side, Brazilians solved an acute labor shortage in the economic boom period, but long‐term recession and casualization of the labor market made them compete with other peripheral workers such as Japanese women and the aged. Thus Brazilians have been marginalized within the secondary labor market since the late 1990s. On the supply side, recruiting agencies and labor contractors established a “just‐in‐time” labor delivery system, which enabled “flexible staffing” in a highly fluctuating labor market. As a result, demand and supply for Brazilian workers is still on the increase. Working in Japan is getting less attractive for Japanese Brazilians but is more of a viable option for them, driving further migration from Brazil to Japan.     

空气压缩机节能技术的研究

论述了气动系统中空气压缩机变速运行的技术。导出了管网工作压力及工作流量与电机转速之间的控制数学模型。利用电机无功功率信号控制调频调压逆变器供电的感应电机的磁通,使其保持恒定、則气路系统在宽流量变化范围內能实现压力自动调节及电机节能。     

制度与农业发展

制度与经济发展有着内在的联系,是经济发展的重要变量.中国农业发展的曲折历程,实质上是中国农业制度选择的曲折.制度对农业发展有着决定性的影响作用,以制度建设为中心就成为解决中国三农问题的必然选择.     

正方程组正解的存在性

本文推广了文[1]的结果,给出了正方程组存在正解的某些新条件.     

A note on sequential ML estimates and their asymptotic covariances

A marginal and sequential maximum likelihood estimation method is described which can be used instead of full information maximum likelihood estimation if the latter method is unfeasible. It is shown that the sequential procedure yields strongly consistent and asymptotically normal estimates under relatively general regularity conditions. It is shown that the covariance matrix of the sequential ML estimator does not coincide with the inverse of the Fisher information matrix. Hence, the corrected covariance matrix is derived. The application of the sequential procedure to the multivariate probit model with dichotomous, ordered categorical, single-sided censored and double-sided censored endogenous variables is included. This research was partially supported by a dissertation grant of theStudienstiftung des Deutschen Volkes. Comments and suggestions on earlier drafts by Gerhard Arminger, Giorgio Calzolari, Bernd Kortzen and an anonymous referee are gratefully acknowledged.     

时频高频信道对数据通信性能的影响

多普勒散布及多径展宽等时频特性会使高频数据通信系的的误码率产生一个不可减小的误码率,根据短波授时自动收测系统和多次包络法测多普勒展宽和多径展宽的测量结果,本文重点讨论二者的时频特性及其对数据通信系统性能的影响。