Optimal investment with vintage capital: Equilibrium distributions

The paper concerns the study of equilibrium points, or steady states, of economic systems arising in modeling optimal investment with vintage capital, namely, systems where all key variables (capitals, investments, prices) are indexed not only by time but also by age. Capital accumulation is hence described as a partial differential equation (briefly, PDE), and equilibrium points are in fact equilibrium distributions in the variable of ages. A general method is developed to compute and study equilibrium points of a wide range of infinite dimensional, infinite horizon, optimal control problems. We apply the method to optimal investment with vintage capital, for a variety of data, deriving existence and uniqueness of equilibrium distribution, as well as analytic formulas for optimal controls and trajectories in the long run. The examples suggest that the same method can be applied to other economic problems displaying heterogeneity. This shows how effective the theoretical machinery of optimal control in infinite dimension is in computing explicitly equilibrium distributions. To this extent, the results of this work constitute a first crucial step towards a thorough understanding of the behavior of optimal paths in the long run.     

超声波技术在食品检测中的应用

超声波技术因其具备适应性强、操作简单、设备投资低等优势而被广泛应用于食品检测领域。本文介绍了超声波技术检测食品的原理和在食品检测中的应用价值,并详细阐述了该技术在食品检测中的具体应用,为超声波技术更好的应用于食品检测领域提供参考。     

私家车从事网约车运营保险争议分析及应对

私家车辆从事网约车载客行为而引起了大量纠纷,结合法院判决和其中事实判断涉及诸多争议。私家车“变脸”网约车进行载客不一定都使得危险显著增加,有些只是兼职网约车司机,风险程度不符合危险显著增加的三个特性,重要性、持续性和未曾估价性。网约车载客与交通事故发生不是必然的因果关系,只是路线不确定和行驶频率增加造成事故风险增加,让保险公司承担全部责任显然违反合同和不符合法律规定,但保险公司直接拒赔商业险也有违对价平衡原则,显失公允。而采用比例原则较为合理,对于网约车这一新兴事物,相关的法律应该既是规制法也是促进法。横向考察域外有较为成熟的网约车保险,UBI车险可以考虑引入,将“人”的因素引入车险定价,具体而言,将考虑事故发生时被保险车辆的状态,以确定保险公司是否承担赔偿责任。     

违反合作原则所产生的幽默效果

幽默在我们日常生活中会起到调节气氛和拉近关系的作用。本文以格莱斯的合作原则为理论支撑,对情景喜剧《老友记》中的幽默效果进行分析,旨在讨论《老友记》的作者是如何通过违反合作原则的方式来创作言语幽默的,尤其是对量的准则和质的准则的违反。     

基于粗糙主成分分析法的铁路网客运节点重要度决策

通过阐述铁路网客运节点的定义和节点重要度的概念,建立客运节点重要度评价指标体系,利用粗糙集理论与主成分分析法的结合,提出利用主成分分析法和基于信息量方法,计算客运节点的客观权重,结合主观权重得到科学合理的客运节点综合权重。经过实例分析,表明了基于粗糙主成分分析法的客运节点评判结果的有效性。     

建筑施工安全管理的原则及其实施措施

本文通过分析建筑施工安全管理的六个原则及当前现状,提出相应的实施措施.     

环渤海区域知识产权保护合作机制研究

在知识经济时代,知识产权和科技进步在我国区域经济发展中的作用日益明显。完善的区域知识产权制度对推动环渤海区域高新技术产业发展和产业结构调整有着中要的作用,也关系到环渤海区域与世界接轨与合作的问题。因此,在实施国家知识产权战略的大背景下,不断完善和规范环渤海渔区知识产权合作机制,把知识产权保护纳入区域经济发展的中心环节,进一步提升科技创新水平,对促进环渤海地区经济可持续发展、提高区域经济竞争力有着重要的意义。     

Risk-based decision analysis in support of precautionary policies

A decision-analytic model for avoiding a risky activity is presented. The model considers the benefit and cost of avoiding the activity, the probability that the activity is unsafe, and scientific tests or studies that could be conducted to revise the probability that the activity is unsafe. For a single decision maker, thresholds are identified for his or her current subjective probability that the activity is unsafe. These thresholds indicate whether the preferred course of action is avoiding the activity without further study, engaging in the activity without further study, or conducting a test or research programme to obtain additional information and following the result. When these thresholds are low, precautionary action is more likely to be warranted. When there are multiple stakeholders, differences in their perceptions of the benefit and cost of avoidance and differences in their perceptions of the accuracy of the additional information provided by the test or research programme combine to create differences in their decision thresholds. Thus, the model allows for the rational expression of differences among parties in a way that highlights disagreements and possible paths to conflict resolution. The model is illustrated with an application to phytosanitary standards in international trade and examined in terms of recent empirical research on lay perceptions of risks, benefits, and trust. Further research is suggested to improve the elicitation of model components, as a way of fostering the legitimate application of risk-based decision analysis in precautionary policy making.     

浅谈合作原则与英语幽默——以美国室内情景喜剧《老友记》为例

Grice的合作原则对幽默的产生机制做出了比较合理的解释，本文力图从四个方面分别加以分析，并结合《老友记》中的相关语料举例说明，试图达到探索言语幽默的语用机制的基本目的。     

Commentary: Morality and workability ­ a rejoinder to O'Riordan

This paper is about understanding the rhetoric of precaution and the practice of decision-making in areas of environmental controversy. It untangles the rhetoric, as established in documented agreements referring to precaution, from the constituent ideas that embody it, as characterized by those who deliberate on its application. By analysing the ways in which the rhetoric of precaution is framed within these documents it is possible to identify different elements that make up the principle in theory. By focussing on the constituent ideas behind the precautionary principle it is possible to move forward from the stalemate of rhetoric that could become the focus of attention itself.