基于复杂网络理论的应急物流网络可靠性仿真研究

首先介绍了复杂应急物流网络的内涵及其统计特征,提出了复杂应急物流网络连通可靠性的评价指标,构建了复杂应急物流网络的拓扑模型并给出攻击仿真方法,最后以某应急物流网络为例,通过在Visual Basic平台下开发的程序,分别对两种攻击模式下该网络连通可靠性进行了仿真分析,得到了相应攻击模式下应急配送时间及有效需求点比例的变化曲线,验证了应急物流网络的复杂网络特性,分析了不同攻击模式对应急物流网络可靠性的影响。     

供应链"公差-配合合作伙伴关系"模型

引入公差配合的概念,系统地研究了供应链体系中的配合选择问题,在分析合作伙伴评估因素和供应链结构的基础上,提出了应用“公差-配合合作伙伴关系”模型描述供应链节点企业间匹配关系的方法,并阐述了该模型的应用方法和应用实例。     

Ecological Fallacy and Covariates: New Insights based on Multilevel Modelling of Individual Data

The paper provides a new and more explicit formulation of the assumptions needed by the ordinary ecological regression to provide unbiased estimates and clarifies why violations of these assumptions will affect any method of ecological inference. Empirical evidence is obtained by showing that estimates provided by three main ecological inference methods are heavily biased when compared with multilevel logistic regression applied to a unique set of individual data on voting behaviour. The main findings of our paper have two important implications that can be extended to all situations where the assumptions needed to apply ecological inference are violated in the data: (i) only ecological inference methods that allow one to model the effect of covariates have a chance to produce unbiased estimates, and (ii) there are certain data generating mechanisms producing a kind of bias in ecological estimates that cannot be corrected by modelling the effect of covariates.     

“十三五”期间我国科研软件发展现状与对策

“十三五”国家创新规划发布以来,我国软件行业取得了巨大的进展。科研软件作为软件行业中的一个细分分支,是科学研究中不可或缺的工具,是引领新一轮科技革命和产业变革的关键力量。因此有必要摸清我国科研软件发展现状和突出问题,研究影响科研软件发展的关键因素。本文通过梳理国家基金委资助项目、国家发布的相关政策、行业现状、人才队伍结构等情况,结合科研软件研发和使用者的特点,分析了科研软件发展中存在的问题,提出了科研软件发展建议等,以期为科研软件的发展及创新提供一定借鉴。     

论保险利益原则的时间效力

保险利益原则的时间效力应区分财产保险和人身保险分别规定。在财产保险合同中，应坚持保险利益是维持合同效力的要件原则，规定有投保时和索赔时都必须存在，只需在索赔时存在的做法只能是货运险的例外。在人身保险合同中，可以规定储蓄投资性的寿险保单及健康保险的保险利益在投保时存在即可，但对于非储蓄性投资性的意外险及定期寿险的保单则可严格要求利益在投保时和保险事故发生时都应存在。     

基于环境价值链的企业管理模式创新

随着资源耗竭、环境危机的频现,＂资源节约、环境友好＂的理念逐步为消费者关注与认同,环保也日益成为企业竞争的焦点,针对这一变化,企业在经营管理过程中必须进行系统的创新以适应变化的市场环境。据此,在对环境价值链阐述的基础上,提出企业管理应从战略、制度、文化三方面进行创新,以提高企业的环保竞争力。     

基于种养结合的种植户粪肥支付意愿研究

[目的]种植户的施用粪肥意愿对降低农业面源污染,提高养殖废弃物综合利用率,保护农村环境意义重大。[方法]利用CVM方法和Tobit模型分析北京市种植户的粪肥支付意愿及影响因素。[结果]98.07%的种植户愿意接受粪肥还田,对粪肥的平均支付意愿为82.99元/m~3。种植户不施用粪肥的主要原因是没有获取渠道与施用粪肥过程繁琐。种植户决策人性别为男性、加入专业合作社、年收入高、接受有机肥补贴、参加过施用粪肥培训、认可粪肥肥效长于化肥、认识到施用粪肥能提高农产品产量对种植户的粪肥支付意愿有显著正向影响。而种植规模大、农田肥力好、认为施用粪肥有助于农产品价格提高对种植户的粪肥支付意愿有显著负向影响。[结论]可以从以下3方面提高种植户的粪肥支付意愿:(1)帮助建立、巩固粪肥交易关系;(2)强化政府职能,提高对施用粪肥的帮扶力度;(3)加强对种植户的粪肥功能认知及环境保护宣传教育。     

Productivity and efficiency with discrete variables and quadratic cost function

We propose an index of productivity based on a quadratic cost function and developed for discrete data including technical and allocative inefficiency, jointly with technical change and returns to scale, as determinants of Total Factor Productivity. This new index is applied to Spanish stevedoring industry so as to identify the sources of change in the productivity of a multiproductive activity, where some companies do not produce some of the outputs. In this context, the functional quadratic form and the productivity index proposed prove particularly useful.     

Is There an Image Crisis in the Spanish Vegetables?

Abstract

The Spanish horticultural sector has been adversely affected by recurring crises in the last years, showing a significant economic impact upon demand. These crises have different sources (internal and external) and origins (food safety, social, and environmental issues). However, research devoted to analyzing the nature and scope of these events and their influence on consumers’ perception is scarce. For this purpose, this research provides a conceptual framework that defines and classifies the main image crises that have affected the sector. Consequently, an exploratory study is conducted to analyze to what extent European consumers know the sector and to determine how consumer knowledge influences the Spanish product-country image. Data were analyzed using a Logit Model. Results suggest that crises have seriously affected the demand of Spanish vegetables and consumers’ perceived image. Factors affecting the sector’s image through consumer knowledge are different depending on consumers’ country-of-origin (national vs. foreign countries).     

The international transmission of monetary shocks across developed countries: The role of imported raw materials

This paper analyzes the implications of a production technology in developed countries (DC) characterized by the share of imported raw materials coming from the less developed countries (LDC). We focus on the question of how this richer productive structure affects the international transmission of a monetary shock across developed countries. In this context, it is shown that (i) the share of raw materials and/or its low substitutability is a source of exchange rate volatility. (ii) Welfare transmission depends critically on the extent of their share in production. (iii) Sufficiently high shares of imported raw materials in the DC production functions explain better positive co-movements between DC outputs.