On a control chart for the Gini index with simulations

In this work we suggest the use of the Gini index on control charts. The asymptotic properties of Gini index are presented and the control charts based on appropriate confidence intervals are constructed. The suitability of the proposed charts are investigated by means of extensive simulations.     

Prediction of future failures times based on Type-I hybrid censored samples of random sample sizes

In this article, we consider the prediction of future failure times based on Type-I hybrid censored samples. Point predictors and prediction intervals using different procedures are discussed for a general model. The exponential and Rayleigh distributions are used as illustrative examples to show the most simplified forms of the so obtained predictors as well as prediction intervals. Intensive simulation study and a real life dataset are presented to illustrate our findings and results.     

Social health protection in Cambodia: Challenges of policy design and implementation

The Government of Cambodia is implementing ambitious reform initiatives to improve the country's social health protection system. In January 2018, it was announced that the Health Equity Fund (HEF), which is fully subsidized by a joint government‐donor initiative for the reimbursement of user fees for the poor at public health facilities, is to be expanded to some segments of informal workers belonging to associations, as well as to commune and village chiefs. Since 2017, the National Social Security Fund (NSSF) has provided social health insurance for formal economy workers in enterprises with eight employees or more. In January 2018, it was expanded to civil servants and all employees regardless of the size of the enterprise. However, this article highlights that the new ambitious reforms are not accompanied by careful planning as regards funding, service delivery, human resources and institutional design. This article therefore aims to examine key policy issues and challenges for Cambodia's ambitious reform of its social health protection system in terms of resource generation, population coverage, strategic purchasing and governance.     

Modeling stereotypes and negative self‐stereotypes as a function of interactions among groups with power asymmetries

Stereotypes is one of the most researched topics in social psychology. Within this context, negative self‐stereotypes pose a particular challenge for theories. In the current work, we propose a model that suggests that negative self‐stereotypes can theoretically be accounted for by the need to communicate in a social system made up by groups with unequal power. Because our theory is dynamic, probabilistic, and interactionist, we use a computational simulation technique to show that the proposed model is able to reproduce the phenomenon of interest, to provide novel accounts of related phenomena, and to suggest novel empirical predictions. We describe our computational model, our variables' dynamic behavior and interactions, and link our analyses to the literature on stereotypes and self‐stereotypes, the stability of stereotypes (in particular, gender and racial stereotypes), the effects of power asymmetries, and the effects of intergroup contact.     

远海岛礁冷链物流体系优化模型及其集成算法

为研究远海岛礁渔获冷链物流的运行方案,本文选择了岛礁冷库储存中转和海上直接收购等两种不同的渔获运输方式,同时考虑了中转冷库选址、中转运输和直接收购船舶配备、航线配置、在渔场停留时间和渔获运输损耗等诸多复杂问题,构建了远海冷链物流体系组合优化模型。求解时,提出了一种以遗传算法（GA）为外部框架,以改进的模拟植物生长算法（PGSA）为内部模块,通过信息传递实现内外连接交互的集成算法。最后,以我国南海远海岛礁及渔场为实例进行分析,取得了较好效果。通过与传统遗传算法对比,本文优化结果、稳定性及计算速度等均有明显提高,从而证明了本文所建模型与算法的合理性和有效性。     

考虑项目关联关系的R&D网络风险传播建模与仿真

考虑同一企业内不同项目间关联关系的情况下,基于研发项目的数量将研发网络分为不同子网络。借鉴SIS模型构建了R&D网络风险传播动力学模型,并对该模型进行了数理解析与仿真分析。结果表明：R&D网络风险传播阈值是由不同子网络的拓扑结构以及企业内不同项目间的关联程度共同决定的;考虑项目关联的研发网络风险传播阈值小于不考虑关联关系的研发网络风险传播阈值;项目间关联关系的企业个数及项目间的关联程度对风险在不同子网络上的传播速度与传播范围均具有影响。该研究成果对于提高研发网络抗风险能力具有重要意义。     

复合期权在R＆D项目投资评价中的应用

如何评价R&D项目投资已成为目前理论界关注的一个热点。对R&D项目投资的基本评价方法———贴现现金流法 (DCF)已越来越不能适应R&D项目管理的复杂性和不确定性 ,而实物期权方法以其能够灵活评价不确定性条件下的投资项目未来的增长机会的特点 ,受到越来越多的关注。借鉴了Geske提出的复合期权模型 ,将R&D项目看作一个复合期权 ,建立了R&D项目的投资评价模型     

中国手机媒体发展前景分析

分析了日本I-MODE取得巨大成功的原因和不足之处,指出无论是从技术上还是从企业模式上,手机媒体在中国的发展都不可能直接拷贝I-MODE模式,只能以I-MODE为借鉴。中国电信发展迅速,手机媒体在中国现阶段发展的重点是手机短信,手机短信市场巨大,但在发展中也存在着一些问题,主要有虚假与不良信息传播、侵犯个人隐私、信息垃圾、信息安全等。然而可以预见,随着3G在中国的逐渐普及以及相关法规的完善,手机媒体将实现网络化、宽带化,将带来一个巨大的媒体市场。     

垂直性研究与开发合作联盟的博弈模型新探

修改了Banerjee和Lin (2 0 0 1)提出的博弈模型 ,在考虑了组成研究与开发 (R&D)成本因素的条件下 ,重新考察了产业内形成垂直的R&D合作联盟的动机 ,得出上游 (或下游 )企业的利润与下游企业的数目之间并不存在特定的关系 ,根据CassimanBrano (2 0 0 0 )的研究结论 ,认为应该对产业中的基础研究工作给予R&D补贴     

三维有机超分子晶体：3-氨基-2-羧基吡嗪

通过溶液法培养了3-氨基-2-羧基吡嗪的单晶,利用单晶X-射线衍射法测定了其晶体结构。同时利用元素分析、红外光谱对其进行了表征。晶体学数据：单斜晶系,P2（1）/c空间群,a=3.7629（7）Ao,b=14.2098（3）Ao,c=10.9212（19）A°^,α=90°,β=99.182（3）°,γ=90°,V=576.47（18）A°^ 3,Z=4,ρcalc=1.603 g·cm^-3,R1=0.0527,WR2=0.1368。结构分析表明,3-氨基-2-羧基吡嗪分子通过氢键作用和π-π堆积作用连接成三维超分子网络结构。