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.     

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.     

全速范围直接转矩控制新型建模与研究

提出了一种适合于全速范围的直接转矩控制系统仿真模型。针对PI参数对系统的影响,改进了PI速度调节器的设计,改善了系统的磁链和转矩控制性能。同时给出了基于MATLAB/SIMULINK的系统仿真模型,仿真结果表明了该方法的正确性,能实现六边形磁链轨迹和近似圆形磁链轨迹的平滑切换。     

一类非线性混合整规划的无约束连续化解法

将整系数多项式 0 - 1混合整规划问题化成无约束多项式规划问题。通过解该问题 ,能得到原问题的近似解。处理方法的特点是能够直接处理不等式约束情形 ,而不需要先将不等式约束化成等式约束再来处理     

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。     

两级供应链Stackelberg主从对策的优化模型及其应用

本文研究了供应链的协调订货模式及其特例,提出了两级供应链Stackelberg主从对策问题模型,其中卖方作为主方给出最小补充期策略,买方作为从方以最优库存策略响应。建立了求解Stackelberg主从对策问题的成本优化模型,并考虑了累积价格折扣激励和买方库存成本合理化。对一个石油分销系统Stackelberg主从对策问题应用遗传算法离线仿真计算,得出Stackelberg均衡解,达到帕累托最优。     

最低收购价政策对小麦市场价格波动影响的实证分析

为了估计最低收购价政策对小麦市场价格波动的直接影响,利用2009年1月4日至2016年12月30日小麦现货与期货价格日数据,通过将政策作为虚拟变量引入GARCH模型,实证研究政策对平抑小麦期现货价格波动的作用,并从政策执行区和非执行区的视角比较政策在不同地区维护小麦市场价格稳定方面的效果,对模型结果和价格传导路径进行验证和分析。结果表明,政策对小麦期现货价格波动产生了明显的影响,能够显著降低小麦现货市场的波动程度,并通过期现货市场间的联系对期货市场产生影响,但政策对期货价格波动的作用方向则相反;政策在平抑小麦价格波动方面的效果具有空间上的溢出效应,通过区域间的市场联系从执行区传导到非执行区,导致非执行区价格波动程度的下降。     

MSE performance of the weighted average estimators consisting of shrinkage estimators when each individual regression coefficient is estimated

In this paper, we analytically derive the exact formula for the mean squared error (MSE) of two weighted average (WA) estimators for each individual regression coefficient. Further, we execute numerical evaluations to investigate small sample properties of the WA estimators, and compare the MSE performance of the WA estimators with the other shrinkage estimators and the usual OLS estimator. Our numerical results show that (1) the WA estimators have smaller MSE than the other shrinkage estimators and the OLS estimator over a wide region of parameter space; (2) the range where the relative MSE of the WA estimator is smaller than that of the OLS estimator gets narrower as the number of explanatory variables k increases.