德国移民法有关条款设计

德国移民法规定,三类“高级专业人才”通过技术移民可以立即获得落户许可,即通常说的“绿卡”,或者说是永久居留权;而投资移民者,无论投资超过规定标准多少倍,首次只能获得有期限的居留许可。     

论中国的绿色发展与林业经济策略

绿色技术经济和林业经济两个领域随着融合发展,研究界限日益模糊,尤其是在生物能源、环境保护和社会经济等方面交叉点日益增多,导致学者难以正确判定这两个领域的独立性和相互关系。为探究两个领域的演化与融合,在Web of Science核心合集数据库进行检索,分别选取绿色技术经济领域文献12 710篇、林业经济领域文献22 990篇进行文献计量分析。通过CiteSpace软件对绿色技术经济领域、林业经济领域进行知识图谱分析,使用Pajek软件对两个领域的演化及融合进行主路径分析。研究结果表明,绿色技术经济领域和林业经济领域研究成果总体上呈逐年增加趋势;绿色技术经济、林业经济研究的演化主要经历了萌芽、探索、发展三个阶段;两者的融合发展体现在碳储存和生物质能源、以森林为基础的生物经济、林业生产中的循环经济三个方面。

     

Solving the minimum M-dominating set problem by a continuous optimization approach based on DC programming and DCA

We propose a new optimization approach based on DC (Difference of Convex functions) programming and DCA (DC Algorithm) to the so-called Minimum M-Dominating Set problem in graphs. This problem is beforehand re-casted as a polyhedral DC program with the help of exact penalty in DC programming. The related DCA is original and computer efficient because it consists of solving a few linear programs and converges after a finite number of iterations to an integer solution while working in a continuous domain. Numerical simulations show the efficiency and robustness of DCA and its superiority with respect to standard methods.     

A New Proposal to Gauge Intergenerational Mobility: Educational Mobility in Europe as a Case Study

This paper is aimed at presenting a new intergenerational mobility index that (a) combines the intergenerational elasticity and the R-squared of the intergenerational regression and (b) enables the expression of the total degree of mobility as the weighted sum of mobility with respect to both parents. As a case study, we apply our proposal to investigate the intergenerational mobility of education in several European countries and its changes across birth cohorts. The results derived from the proposed index indicate that Nordic countries display higher levels of educational mobility than Southern countries, whereas continental countries are in an intermediate position. Moreover, it appears that the degree of mobility increases over time only in those countries with low initial levels and remains stable for the most mobile countries. Finally, for most of the countries the proposed methodology can prove that the degree of educational mobility with respect to each parent tends to converge to the same level over the course of time.     

基于社会网络分析的意见领袖网结构

微博中的意见领袖主导了大量的信息流动,通过分析他们之间的关系,可以理解微博平台的传播结构。用两阶聚类分析法对新浪微博中的数据进行分析,识别出具有社交网络特征的意见领袖群体,再用社会网络分析方法将识别出来的群体构建成意见领袖网,分析该网络在中心度、密度等方面的特征。实证分析表明:网络中的成员连接关系紧密度不高,网络中没有直接关系的成员要建立联系的平均距离较近,网络中位于核心位置的成员中心化程度不高。     

如何实现企业人力资源的合理配置

企业人力资源配置包括个体和整体配置。个体配置是在工作岗位分析、评价和分类的基础上,一方面以事为中心,为事择人;另一方面以人为中心,     

读《对女性／社会性别学的再思考》

女性／社会性别学;西方女性主义理论;西方女性主义第二波;女性／社会性别学方法论;女性主义历史的“三波论”     

唐朝的潭水

唐朝的那池潭水,越千年了,依旧清且涟漪.昨日发现,那潭水经雾雨雪霜几多形态变化,已从永州流到辽西朝阳,我的舍畔.只是潭中原来那百许头鱼已不见踪影,恍惚的还闪两尾亮儿,疑是柳宗元游移的目光.     

A Computational Framework for Prime Implicants Identification in Noncoherent Dynamic Systems

Dynamic reliability methods aim at complementing the capability of traditional static approaches (e.g., event trees [ETs] and fault trees [FTs]) by accounting for the system dynamic behavior and its interactions with the system state transition process. For this, the system dynamics is here described by a time‐dependent model that includes the dependencies with the stochastic transition events. In this article, we present a novel computational framework for dynamic reliability analysis whose objectives are i) accounting for discrete stochastic transition events and ii) identifying the prime implicants (PIs) of the dynamic system. The framework entails adopting a multiple‐valued logic (MVL) to consider stochastic transitions at discretized times. Then, PIs are originally identified by a differential evolution (DE) algorithm that looks for the optimal MVL solution of a covering problem formulated for MVL accident scenarios. For testing the feasibility of the framework, a dynamic noncoherent system composed of five components that can fail at discretized times has been analyzed, showing the applicability of the framework to practical cases.