The covariance of the number of renewals in a fixed time and the ensuing excess life

The covariance of the number of renewals in a fixed time N ^t and the ensuing excess life time Y ^t is derived using matrix-analytic methods for the stationary PH-renewal process. Specific results for the Erlang and hyperexponential processes are provided to illustrate the ease of computation. Properties concerning the sign and the behavior of the covariance as t→∞ are provided throughout. Parameter estimation for renewal processes which cannot be fully observed serves as the motivation for our derivations. These statistical applications as well as links to estimation for service time distributions in queues shed light on the type of problems for which the covariance is useful.     

美国第二轮量化宽松货币政策影响分析

随着金融危机的不断蔓延和影响的逐渐深化,美国采取第二轮量化宽松货币政策来稳定和刺激经济,此种非常规货币政策将对全球经济产生深远影响,对作为全球第二大经济体的中国也将产生不利影响。针对第二轮量化宽松货币政策可能对中国经济产生的不利影响,从第二轮量化宽松政策的启动入手,通过分析第二轮量化宽松货币政策所采取的主要措施及其传导机制,在分析量化宽松货币政策对全球经济影响的基础上,提出中国的对策,以期为中国相关经济政策的制定提供一定的参考。     

The economic effects of common agricultural policy on Mediterranean montado/dehesa ecosystem

The decoupling of CAP payments leads production decisions and resources allocation to be more dependent on market prices and competitive advantages. The objective of this paper is to assess the effects of CAP trends on the montado/dehesa traditional ecosystem of Mediterranean regions in terms of farm income, land, labour and capital. A positive mathematical supply model disaggregated by the montado agro-forestry production systems of the Alentejo region in southern Portugal is developed. The results show that decoupling payments of CAP have negative economic effects on agricultural activities and resource use. Agricultural income increases with single farm payments but the foreseen increases in prices do not compensate the loss of the Agenda 2000 area payments in terms of competitiveness. These results reinforce the need to promote alternative agricultural and non-agricultural activities and policies in Mediterranean rural European areas and regions.     

Inclusive innovation and the role of technological capability-building: The social business Grameen Danone Foods Limited in Bangladesh

This article examines how a least developed country-based social business first creates operational capabilities (OCs) and then, over time, builds innovative capabilities (ICs) to fulfil a social need, be self-sustainable and achieve inclusive innovation. This relationship is examined in Bangladesh's Grameen Danone Foods Limited (GDFL) by integrating the technological capability and inclusive innovation theoretical frameworks and by using data gathered through extensive fieldwork. Broadly, our findings show how GDFL built and accumulated basic and intermediate ICs to undertake innovative activities in all areas of operation. Specifically, our findings scrutinize the process in which a social business develops and organizes its resources to initially build OCs and engage in the creation of ICs through various learning mechanisms to deliver inclusive innovation. From this process, we also observe a set of unpredicted positive spillovers to the community, which expands the inclusiveness effect. The findings also suggest that having a social orientation, triggers the use of different resources from within and outside the firm to achieve inclusive innovation. We conclude by discussing the study's implications for scholars, policy-makers and managers of multinational's social businesses. We also highlight future research areas, and crucially those related to key emerging conceptual limitations of inclusive innovation and development.     

Social norms, cognitive dissonance and the timing of marriage

We present a model of courtship in which the timing of marriage is affected by the cognitive dissonance between perceived norms and personal aims. We argue that as long as the family has been the main provider of social protection, marriage has been favoured by strongly felt social norms, and thus people accepted less-than-ideal partners early on in their search in order to minimise the dissonance caused by the non-adherence to the custom. Once the Welfare state has replaced the family, these norms have lost their strength, so that agents can afford the luxury of searching their preferred partners at length without feeling at odds with their social duties. The model yields predictions in line with relevant stylised facts: the raising age of marriage, the prevalence of assortative mating and the common occurrence of divorce in the early years of marriage. We finally discuss the impact of late marriages on fertility, and argue that there need not be negative consequences if the declining role of the family becomes socially accepted, and alternative arrangements are made possible and indeed encouraged by means of an appropriate family policy.     

H2O2催化湿式氧化酸性红B染料废水的研究

以自制的复合氧化物Fe2O3-NiO-CeO2/γ-Al2O3为催化剂氧化降解酸性红B染料废水,考察了进水pH值、反应温度、氧化剂及催化剂用量对COD去除率的影响。结果表明,在反应温度为90℃,进水pH为7,催化剂投入量2g（300mL废水）,双氧水用量18mL时,酸性红B的COD去除率可达到87.6%。     

Go/NoGo实验下NoGo-N2、P3效应分析

在Go/NoGo实验范式下用事件相关电位研究反应抑制脑机制时,传统的研究结果显示在大脑前额区NoGo任务下的N2、P3成份分别相对于Go任务有负向、正向的偏移,即NoGo-N2效应和NoGo-P3效应。由于在Go任务中行为反应引发了运动相关成份的叠加效果,可能导致真实的NoGo-N2、P3效应被掩盖。为了恢复真实NoGo-N2、P3效应,采用刺激、反应成份分解算法消除Go条件下运动相关成份的影响。结果表明,NoGo-P3效应来自运动相关成份的叠加效果,有可能与反应抑制过程无关,而NoGo-N2效应则反映了反应抑制过程。     

脱钙模拟椎体骨质疏松体外模型的建立

目的 利用乙二胺四乙酸二钠盐(EDTA-Na2)体外脱钙模拟椎体骨质疏松,测量猪3联椎体骨密度和生物力学的特性,探讨一种短期制造骨质疏松性椎体压缩骨折模型的方法.方法 取49个新鲜猪胸腰椎3联体,随机分成7组,记为A.B.C.D.E.F.G每组7个标本.然后把B.C.D.E.F.G标本侵入0.4916 mmol/L的EDTA-Na2脱钙液体中,分别在0、5、7、9、11、13、15天分别行A.B.c.D.E.F.G骨密度、生物力学、Mcro-ct检查及每组取一个标本大体剖开.结果 随着脱钙时间的延长,大体观察可见各组标本骨小梁逐渐变细、间隙增宽,骨密度检测结果显示逐渐减低的趋势,并且各组脱钙前后骨密度变化均有明显的差异性(P=0.0000).随着脱钙时间的延长椎体压缩强度逐渐降低,脱钙前后相比压缩强度均有显著性差异(P=0.0000).Micro-CT检测脱钙13天椎体及棘突骨矿物质密度、组织骨密度、骨体积分数、结构模型指数、欧拉数、骨小梁连结密度均有明显的变化(P≤0.02).结论 采用0.4916 mmol/L EDTA-Na,脱钙11～13天可模拟中、重度骨质疏松性椎体压缩骨折,是一种快速、可行、重复性高的方法.     

Assessing Short-Term Fertility Intentions and Their Realisation Using the Generations and Gender Survey: Pitfalls and Challenges

The use of fertility intention questions to study individual childbearing behaviour has developed rapidly in recent decades. In Europe, the Generations and Gender Surveys are the main sources of cross-national data on fertility intentions and their realisation. This study investigates how an inconsistent implementation of a question about wanting a child now affects the cross-country comparability of intentions to have a child within the next three years and their realisation. We conduct our analysis separately for women and men at prime and late reproductive ages in Austria, France, Italy and Poland. The results show that the overall share of respondents intending to have a child at some point in their life is similar in all four analysed countries. However, once the time horizon and the degree of certainty of fertility intentions are included, substantial cross-country differences appear, particularly in terms of proceptive behaviour and, consequently, the realisation of fertility intentions. We conclude that the inconsistent questionnaire adaptation makes it very difficult to assess the role of country context in the realisation of childbearing intentions.     

高校数字化校园建设研究

在阐述了数字化校园的概念内涵后，对数字化校园结构模型进行了分析，并对高校数字化校园建设实现技术进行了详细探讨。