实数域及四元数除环上有平方根的方阵

给出了实数域及实四元数除环上方阵有平方根的充分必要条件．     

Weakly implementable social choice rules

Previous investigations have shown that a social choice function which is partially implementable must be characterized by pervasive veto power. This paper investigates how much additional latitude in the design of social choice functions, and how much relief from this vetoers result, can be achieved by examining multi-valued social choice rules and relaxing the requirement of partial implementability to a requirement that we call weak partial implementability. We find that the power structures which characterize partially implementable social choice functions, including the veto properties, also characterize weakly partially implementable social choice rules. The conclusion is that invoking multi-valuedness and implementation of appealing social choice rules in strong Nash equilibria. Our results apparently exhaust the possibilities for implementation in strong Nash equilibrium. If any implementation possibility results are to be achieved, they can apparently come only by weakening the equilibrium requirement.     

Les transformations de l'intégration par l'emploi: Regards croisés : France métropolitaine - île de La Réunion

Against a background of mass unemployment and the increasing precariousness of employment, the current changes in the labour market demand that we examine the previously central role of paid employment in social integration. If the individual now deprived of employment or having a temporary contract is by dint of this fact less included in society or is less secure by not having a permanent salary, is it to say that he embodies the face of the de-affiliated, of those who miss out on social benefits? Taking the example of the Reunion Island which has the highest level of unemployment and population covered by the minimum income (RMI: Revenu Minimum d'Insertion) in the country, this article endeavours to explain and understand how, in the context of a protective society and increasingly flexible employment market, new methods of social integration without and resulting from paid employment are being formed.     

论科技期刊的品牌资本

科技期刊的品牌资本是其生存和发展的关键因素,品牌资本体现了社会效益与经济效益的同一性。品牌资本的价值回归是一个缓慢但却是相当稳定的过程。通过抽样调查和方差分析,定量说明了上述论点的正确性。     

随机型细胞神经网络的稳定性

借助于李雅谱洛夫理论、矩阵分析方法和It?公式,结合不等式分析技巧,研究了随机细胞神经网络系统的均方指数稳定性,给出了系统的解的二阶矩Liapunov指数估计式和均方指数稳定的充分条件。     

贫困地区低保动态管理探析

本文从贫困人口需求获得经济利益与主体管理部门动态性控制二者的矛盾入手,对贫困地区低保动态管理的内涵进行了探析,并将低保动态管理分为三个类型:一是对象平行动态,二是实行标准上下动态,三是需求类型变化动态,进而提出了解决低保动态管理问题的路径及措施.     

多元线性回归方程及其应用

通过建立多元线性回归的数学模型,利用最小二乘估计得到正规方程组并进行相关性检验,从而解决相关实际问题。     

Making ends meet: perceptions of poverty in Sweden

During the era after the Second World War, Sweden has built a welfare system based on labor market participation and income maintenance. Low unemployment and decent wages are supposed to guarantee people a labor market income or income maintenance, which in turn should provide a proper standard for everyone. However, a rapid increase in unemployment and economic problems have made the future of the Swedish welfare state more uncertain than ever. These circumstances have, among other things, led to the suggestion that Sweden should abandon the income maintenance policy and create a social policy system with the more limited ambition of guaranteeing everyone a minimum income. In that case, one central question must be answered: what constitutes a decent minimum income in today's Sweden? Where should we draw the poverty line under which people will not be forced to live? These questions are central in the current debate. The consensual poverty line method is used in this article to derive a poverty line relevant for today's Sweden. The results shows that more than every fifth household has an income below the consensual poverty line. That is, they have an income that most Swedes would argue is too low to make ends meet. The level of the consensual poverty line was compared with the National Board of Health and Welfare's guidelines for social assistance. The consensual poverty line was shown to be more generous to small households and the norm for social assistance was more generous to larger households. Finally, the expenditure for guaranteeing all Swedish household a minimum income equal to the consensual poverty line was estimated: more than SEK 25 billion per year. The results in the article casts serious doubt on the ability of the Swedish welfare state to secure a decent income to all citizens.     

基于复杂网络的投资组合优化研究

本文基于复杂网络的局部聚类系数改进了传统的全局最小方差投资组合模型。首先通过股票对数收益率的相关系数矩阵构造股票关联网络,然后计算股票关联网络的局部聚类系数,最后通过全局最小方差模型确定最佳投资组合。将改进后的模型应用于A股市场,经过夏普比率、信息比率和欧米茄比率的对比分析得出改进后的投资组合模型在样本外的表现优于传统的全局最小方差投资组合模型。     

资源环境约束下中国TFP增长的空间差异和影响因素

运用DDF模型和ML生产率指数,对中国分省资源环境约束下的区域全要素生产率进行测算,采用Theil指数测算资源环境约束下中国全要素生产率增长的地区差异并按照多种空间尺度进行区域分解;构建空间面板数据模型,采用广义空间面板自回归最小二乘法对资源环境约束下全要素生产率增长的影响因素进行实证研究。研究结果表明,在2010年之前,资源环境约束下中国全要素生产率增长的空间差异总体上呈下降态势,地区内而非地区间差距是造成总体空间差异的主要来源。空间计量模型回归估计结果表明,资源环境约束下全要素生产率增长存在显著的正向空间溢出效应,经济发展水平、贸易开放和科技创新水平对资源环境约束下全要素生产率增长存在显著的促进作用,产业结构、能源结构和要素禀赋结构等结构因素对全要素生产率增长存在显著的负向影响,外商直接投资和环境规制水平对全要素生产率增长的影响在统计上并不显著。