透平平面叶栅大负攻角分离流的研究

为了研究透平叶栅大负攻角分离流动的性质,在平面叶栅风洞上对叶栅流道内部及出口半叶高处的流场作了细致的测量,并测得了相应叶高处的叶型表面静压分布。用流动显示方法确定了叶型压力面上的分离区,初步拟出了分离流流型,并用二维时间推进法计算了无分离及有分离时的流场,得到了与实测值较为吻合的叶型表面静压分布及其它流动参数的分布。     

Philosophical Views and Basic Theories of System Dynamics

System dynamics, founded by professor Forrester at Massachusetts Institute of Technology in 1956, is a discipline which analyzes and studies the system of information feedback. Basic views of theories of system dynamics distinctively show its dialectical characteristics. More attention should be paid to the features of complicated nonlinear systems. The model simulation of system dynamics is a kind of structure-function simulation. One of the remarkable advantages of system dynamics is that it can handle problems of high order, nonlinear and multiplefeedback system.     

Live-in Foreign Domestic Workers and their Impact on Hong Kong’s Middle Class Families

This paper discusses the impact of foreign domestic workers (FDWs) on parental roles and family dynamics of Hong Kong’s middle class families. The increase in married women’s labor force participation in Hong Kong has led to a greater demand for childcare, which has been filled by FDWs. Based on interviews with 15 dual-earner couples in middle class nuclear families employing FDWs, how FDWs affect the mother’s gender role and family dynamics is discussed. Boundary work is used by parents in their daily interaction with their children and their FDWs so as to reconcile the perceived indispensability of these workers on the one hand, and the challenges they pose to the definition of parenthood on the other. This research was funded by a Lingnan University Social Sciences Program Research Grant RES/SOC010/978. I am grateful to the guest editors and two anonymous reviewers for their valuable comments.     

Some aspects of modern population mathematics

The purpose of this paper is to survey a number of the technical tools and models that have found use in the study of human and other populations, and to indicate some problems of current interest. These tools and models are varied: integral equations, nonlinear oscillations, differential geometry, dynamical systems, nonlinear operations, bifurcation theory, semigroup theory, martingale theory, Markov processes, diffusion processes, branching processes, ergodic theory, prediction theory and state-space models. A fairly extensive bibliography is provided. Also an Appendix has been added describing the analysis of a classical entomological data set.     

基于进化博弈的专利联盟形成研究

专利联盟作为高新技术产业发展的主导范式,对技术标准的建立有重要的作用。但是多数情况下提高社会福利的联盟却难以形成,这就是所谓专利联盟的形成困境问题。从专利权人的有限理性和重复博弈角度分析专利联盟的形成,分别建立对称和非对称专利联盟形成的进化博弈模型,得到不同条件下的进化稳定策略,并探讨影响联盟形成的条件和因素。研究结果表明,专利联盟更容易在弹性高、竞争激烈的市场环境中形成;与事实标准建立以后相比,在事前组建的专利联盟形成可能性更大;通过多方途径保护和提高加入联盟的专利权人的利润,同时抑制阻碍联盟的专利权人的利润,是促进联盟形成的关键;与专业R&D企业相比,纵向一体化企业有更强的动机加入联盟。健全和完善相关法规及配套服务对联盟形成也是有益的。     

基于系统动力学的“互联网+健康医疗”体系模型

“互联网+健康医疗”模式已然成为我国健康医疗产业发展的一个新方向,为解决传统医疗行业中存在的诸多问题提供了新思路。在分析“互联网+健康医疗”对传统医疗的影响及其发展机制的基础上,利用存量流量图等工具构建“互联网+健康医疗”体系模型,运用Vensim软件对我国“互联网+健康医疗”发展情况进行仿真,并模拟相关政策的干预效果。结果表明:“互联网+健康医疗”在降低潜在医疗需求(PMD)、促进分级诊疗中具有重要作用,保障医疗保险能够较好地嵌入“互联网+健康医疗”就诊流程中对降低PMD最有意义,而降低整体门诊价格对于优化就医结构、促进分级诊疗最为有效。     

基于SEM模型的流动人口迁移意愿研究

流动人口迁移意愿一直是流动人口研究的热点问题。首次将结构方程模型应用到流动人口迁移意愿影响因素的研究中,通过选取经济条件、生活环境、社会福利保障、迁移意愿4个潜在变量,采用问卷调查获取数据,构建流动人口迁移意愿SEM模型。结果表明:基于SEM的流动人口迁移意愿影响因素分析模型拟合效果较好,为流动人口服务管理相关政策的制定,提供了更加科学的依据。     

Distribution of busy period in stochastic fluid models

We consider the busy period in a stochastic fluid flow model with infinite buffer where the input and output rates are controlled by a finite homogeneous Markov process. We derive an explicit expression for the distribution of the busy period and we obtain an algorithm to compute it which exhibits nice numerical properties.

     

旅游城镇化驱动乡村振兴的影响效应研究

旅游城镇化作为新型城镇化的一种典型模式,是新发展阶段实现乡村振兴的有效路径。以张家界武陵源区为例,紧扣旅游城镇化驱动乡村振兴的关键影响因素和传导路径,基于系统动力学方法对旅游城镇化驱动乡村振兴的影响效应进行仿真模拟。研究发现,旅游城镇化对乡村振兴的驱动是一个复杂的动态过程,需精准分析旅游城镇化作用乡村振兴的不同路径及其影响效应;武陵源区目前的自然发展模式虽能创造较好的经济增长效应,但会造成结构性失业、资源破坏和环境污染等问题;在5种仿真模式中,兼顾经济-社会-环境的协同发展路径是推进乡村振兴的最佳模式;旅游政策影响因子在不同仿真模式中均成为重要的政策因子,印证了武陵源区旅游发展在乡村振兴战略中的重要地位。实现旅游城镇化对乡村振兴的最佳驱动必须从经济增长、社会文化与生态优化三个层面联合发力,以系统化的协同发展路径促进乡村振兴。研究有助于进一步理解旅游城镇化与乡村振兴的多元内在关系,为我国乡村地区尤其是西部民族地区的乡村振兴提供借鉴。