中国对“一带一路”沿线国家出口持续期及影响因素研究

“一带一路”倡议提出后,中国对沿线国家的出口贸易总量已经有所突破。与此同时产品出口是否也变得更加稳定？出口贸易的稳定性决定贸易联系的长期发展,稳定的贸易联系有利于中国企业的稳定发展。本文利用高度细分且重复观测的出口纵向生存数据,利用Cox随机效应混合模型进行两种时期的对比研究,并在模型中考虑交互作用。研究发现,“一带一路”倡议提出后,总体上,向沿线各国出口贸易更加稳定,各地区差距明显缩小,高技术产品出口稳定性显著提升,技术型产品与非技术型产品拉开了差距,出口产品结构有所优化。同时,倡议的提出对于GDP或人均GDP较低国家的出口稳定性推动最明显,尤其体现在技术型产品上。“一带一路”倡议提出后,出口贸易几乎不受汇率波动影响,倡议的提出在一定程度上削弱了远距离对出口的不利影响,且较大的初始贸易额所带来的优势对高技术产品出口稳定性的促进作用最明显。双边贸易联系的紧密性体现得更明显,而且双边贸易联系越紧密越有利于技术型产品出口。     

System reliability under δ-shock model

δ-shock model is one of the widely studied shock models in reliability. Under this model, the system fails when the time between two consecutive shocks falls below a fixed threshold δ. In this paper, the survival function and the mean time to failure of the system are obtained when the times between successive shocks follow proportional hazard rate model.     

我国医疗保障事业发展的历程和经验

我国医疗保障事业建立、改革、发展经过了计划经济体制下的单位保障、市场化改革背景下的医疗保险、全面建设小康社会目标中的全民医疗保障。发展我国的医疗保障事业必须以科学发展观为指导,将保障人民健康作为根本宗旨;医疗保障事业建设必须立足国情,与经济发展水平相适应;各项医疗保障必须要协调发展,积极推进医疗保障制度一体化;医疗保障与医药卫生服务体系建设必须要全面推进,深化医药卫生体制改革。     

农村社区养老:模式、问题与对策

老龄化使得农村养老服务需求增加与供给短缺的矛盾日益突出,农村社会传统的养老模式受到冲击。农村社区养老以其功能优越性提供了一种解决农村养老服务供需矛盾的路径。     

失地农民问题研究述评

随着城市化进程的不断加快,失地农民问题已扩展为全国性的社会问题,严重影响到我国社会经济发展和和谐社会的构建。如何妥善处理好失地农民问题,不仅成为实践操作的需要,更成为学界关注的热点。本文对已有文献进行整理后,梳理出失地农民四大热点问题,对每个问题都作了简要述评,指出了现有研究的不足及需要改进的地方。     

农村计生家庭中老年父母养老现状调研

通过对江苏、江西、山西、贵州四省五县980位农村计生家庭50岁以上中老年父母经济状况、生活状况、健康情况、社会支持、亲子关系以及心理情绪等方面的调查发现,这一特殊群体近90％的人靠种地和打零工为生,缺少稳定的经济来源,半数以上家庭年收入在3000元以下,仍处于贫困阶段,自我养老能力十分有限,在未来的岁月中由于年龄增长自我提升的可能性较小,加上子女赡养能力不足,所患疾病以障碍型慢性病为主,社会保障压力势必表现出渐进性加大的态势,据此,政府和社会应成为对这部分老年人提供养老相关保障的主要担当力量。     

和谐社会理念下的城市公共安全体系建设探讨

我国正处于经济社会转型的关键时期,也正是城市发展的＂矛盾凸显与不稳定＂时期。近几年来城市各类突发性事件频频发生已折射出城市公共安全体系建设的重要性和紧迫性。＂非典＂事件过后,以北京、上海和深圳为代表的城市对公共安全管理模式作了较为有效的探索。但我国城市整体公共安全体系建设仍处于初步阶段,存在着不少问题与不足。应以＂三个代表＂重要思想、科学发展观和和谐社会理念为指导,加强公共安全组织系统、预警系统、应急处理系统、信息系统以及法律法规系统等几个子系统建设。     

提高农民种粮经济收益是确保国家粮食安全的关键

提高农民种粮经济收益是确保国家粮食安全的关键.粮食的自然、社会与经济特性决定了农民种粮经济收益偏低;较低的种粮经济收益驱使农民的主体行为选择不利于国家粮食安全;同时,发达国家粮食生产经验也表明确保国家粮食安全必须提高农民种粮经济收益,增强其种粮积极性.我国粮食总产量与粮食人均占有量均呈"N"形波动,呈现非稳定状态,表明我国粮食安全存在问题,其根本原因是我国种粮经济收益低且呈明显下降趋势.为缓解这一趋势,切实提高种粮经济效益,确保国家粮食安全,就需创建以控制种粮成本、降低种粮风险、提高粮食产品价值为核心的三维框架体系.     

A Bayesian hierarchical mixture model for platelet-derived growth factor receptor phosphorylation to improve estimation of progression-free survival in prostate cancer

Summary.  Advances in understanding the biological underpinnings of many cancers have led increasingly to the use of molecularly targeted anticancer therapies. Because the platelet-derived growth factor receptor (PDGFR) has been implicated in the progression of prostate cancer bone metastases, it is of great interest to examine possible relationships between PDGFR inhibition and therapeutic outcomes. We analyse the association between change in activated PDGFR (phosphorylated PDGFR) and progression-free survival time based on large within-patient samples of cell-specific phosphorylated PDGFR values taken before and after treatment from each of 88 prostate cancer patients. To utilize these paired samples as covariate data in a regression model for progression-free survival time, and be cause the phosphorylated PDGFR distributions are bimodal, we first employ a Bayesian hierarchical mixture model to obtain a deconvolution of the pretreatment and post-treatment within-patient phosphorylated PDGFR distributions. We evaluate fits of the mixture model and a non-mixture model that ignores the bimodality by using a supnorm metric to compare the empirical distribution of each phosphorylated PDGFR data set with the corresponding fitted distribution under each model. Our results show that first using the mixture model to account for the bimodality of the within-patient phosphorylated PDGFR distributions, and then using the posterior within-patient component mean changes in phosphorylated PDGFR so obtained as covariates in the regression model for progression-free survival time, provides an improved estimation.     

Visualizing uncertainty in reliability functions with application to aero engine overhaul

Summary.  We propose an approach for estimating the date of lost confidence of jet engines, which are devices with multiple components subject to disruption. A mixed Weibull distribution is estimated from a large data set subject to censoring at various times. Parametric uncertainty is derived analytically and mapped visually onto the functions of use in reliability theory, including the hazard function. We demonstrate the use of the method on a database of disruption times for components in 325 jet engines.