基于LUC密码体制防欺诈的秘密共享方案

基于LUC密码体制,提出一种防欺诈的(t,n)门限秘密共享方案。在秘密恢复过程中,任何参与者能够对其他参与者所出示的子秘密进行验证,不仅能有效地阻止敌手窃取秘密,也能有效地防止内部成员之间的相互欺骗;各参与者的子秘密长度与秘密长度相同,方案的信息率为1,是一个理想的方案。该方案的安全性是基于LUC密码体制和Shamir的(t,n)门限秘密共享方案的安全性。     

Between reform and inertia: Bolivia's employment and social protection policies over the past 20 years

With the coming to power in 2006 of Evo Morales' Movement Toward Socialism, Bolivia entered a new stage in its history: a period of ambitious political and economic reform aiming to transcend the neo‐liberal development model in place since 1985 and to renew the State on the basis of its new Constitution, drawn up in 2008. Against this background, this article examines changes in labour law and social protection during the 1980s and 1990s and takes stock of the challenges of implementing a development strategy focusing on full employment and equity.     

高等院校物流管理专业实习实训方案的设计

随着我国社会经济的不断发展,物流领域出现了专业人才匮乏的现象。在社会对物流人才需求旺盛的情况下,很多高等院校相继开设了物流管理专业,以期通过大量培养物流管理专业的人才来满足相关企业的需求。但是在实践中,很多物流管理专业的学生在实习工作中缺少应变能力,实践能力弱,不能达到物流企业的用人标准。对目前高等院校物流管理专业实习实训方案进行了分析探讨,以期设计出一个相对完善、创新的物流管理专业实习实训方案,促进物流管理人才的培养,有效满足当前物流管理人才供不应求的紧张局面,促进我国整个物流领域更好更快地发展。     

Schematic saturated orthogonal arrays obtained by using the contractive replacement method

This paper presents a general method of constructing schematic saturated orthogonal arrays of strength two. We consider a class of mixed saturated orthogonal arrays produced from saturated symmetric orthogonal arrays by using the contractive replacement method, study the Hamming distances of the rows, construct their association schemes, and prove that they are schematic. Some examples are given to illustrate this construction method.     

The challenge of pension reform in Georgia: Non‐contributory pensions and elderly poverty

Georgia's national social security system offers almost universal non‐contributory basic pension coverage. The basic pension has, to date, proved effective in dealing with old‐age poverty. But Georgia's fiscal constraints and ageing population also highlight the importance of improving the pension system, in order to ensure its sustainability. This article presents policy reform choices, which suggest that, in Georgia, pension reform might include increasing the statutory retirement ages and reducing the generosity of benefits through means testing. The case of the Georgian non‐contributory basic pension might hold value for some low‐ and middle‐income countries that are considering the implementation of, or expanding coverage under, a non‐contributory pension programme.     

The gender gap in pensions in Latin America

Lower female lifetime labour market participation rates, greater interruptions during their working lives, and wage gaps contribute to create gender gaps in pensions at the time of retirement. The design of social security systems may reinforce or attenuate these gaps. This article provides new evidence on gender gaps in access to pensions and in pension income in four Southern Cone countries in Latin America and analyses their evolution between 2000 and 2013, showing significant improvements in both gaps, with differential patterns by countries. The decrease in the gender gap in pension income has been particularly significant in Argentina and Brazil. In both cases, the largest increases in pension values during the period correspond to the lowest income percentiles, where women are overrepresented. The application of redistributive policies in these countries, aimed at reducing poverty and inequality but not necessarily focused on gender equity, has had positive and probably unintended consequences in terms of reduction in gender gaps in pensions.     

Pension reforms in EU11 countries: An evaluation of post‐socialist pension policies

This article evaluates the pension policy pathways of the 11 former state socialist nations that have joined the European Union since 2004. Focusing primarily on the post‐2004 period, the analysis discusses the most important measurable outcomes of these countries’ pension reforms, in terms of poverty alleviation, pension adequacy and fiscal sustainability. Going beyond the quantifiable concepts, we also investigate the quality of the 11 countries’ pension systems in terms of equity as well as efficiency, emphasizing the less conspicuous design errors present in these systems. Although these errors have received little attention to date, they may harm pension schemes along several dimensions, including their fiscal sustainability.     

Can the minimum living standard guarantee scheme enable the poor to escape the poverty trap in rural China?

The rural Minimum Living Standard Guarantee (Dibao) Scheme is the most important social assistance programme in rural China. However, how the rural Dibao programme affects household expenditures and whether it can enable the poor to escape the poverty trap are questions that remain largely unexplored. This study used data from the 2012 Rural Household Survey in China to investigate the impact of the rural Dibao programme on household expenditures. We found that the programme significantly improved the well‐being of low‐income households. Particularly, the programme significantly increased household expenditures on housing, education and health; furthermore, the impact was greater for households with educated household heads. However, the programme did not significantly affect household expenditures on food, transportation or farming inputs. The results imply that participation in the rural Dibao programme induces household investment in human capital, which could help to break the inter‐generational transmission of poverty and raise long‐run welfare.     

Variable selection for semiparametric proportional hazards model under progressive Type-II censoring

Variable selection is an effective methodology for dealing with models with numerous covariates. We consider the methods of variable selection for semiparametric Cox proportional hazards model under the progressive Type-II censoring scheme. The Cox proportional hazards model is used to model the influence coefficients of the environmental covariates. By applying Breslow’s “least information” idea, we obtain a profile likelihood function to estimate the coefficients. Lasso-type penalized profile likelihood estimation as well as stepwise variable selection method are explored as means to find the important covariates. Numerical simulations are conducted and Veteran’s Administration Lung Cancer data are exploited to evaluate the performance of the proposed method.