基于Python平台通过单因子指标法进行地下水质量评价

水质评价关系到水质质量,常见的评价方法有层次分析法、综合评价法等,这些方法评价过程非常复杂,单因子评价方法相比具有操作容易.实际中单因子进行评价时存在概念理解难、计算容易出错等问题.为解决单因子计算问题,本文提出采用Python编程语言进行单因子评价.本文详细分析了Python进行单因子评价流程,从数据采集、数据清洗、数据处理、系统实现进行分析.应用结果表明基于Python编程的单因子评价方法具有评价效率高、准确度高优点.     

Pricing practices and firms' market power in international cellular markets, an empirical study

Previous studies on international marketing have typically asked the question: “how is the demand characterized across countries?” Such analysis is then used to provide guidelines for firms to enter new markets and/or to allocate marketing resources across countries. To provide such normative guidelines, however, one also needs to analyze the supply-side of the problem, i.e., ask: “what is the likely market power that firms will be able to command in different countries?” Building on the New Empirical Industrial Organization (NEIO) framework, recent research in marketing provides marketers with a variety of models to explore competitive interactions among firms in the context of a single market. The goal of this paper is to extend this literature to a multimarket/multinational context to help international marketers assess the likely market power they face when entering new countries. We illustrate the proposed method on the mobile telecommunications industry, using price and quantity data from 10 countries around the world, estimating firms' market power as a function of a number of country characteristics.The results indicate that, while the simple presence of competition diminishes firms' market power, it does not lead to perfect competition. Interestingly, a higher number of competitors in a country does not seem to have significant incremental effect on market power. In contrast, the country's commitment to a severe antitrust policy has a significant negative effect, while the monopolist's lead-time before competition is allowed has a significant positive effect on market power. These findings, together with a change in price elasticities as a result of competition, suggest that market power in different countries may originate from two sources: (i) collusive pricing among cellular operators and (ii) consumers' switching costs across service providers. For international marketers, the findings imply that the attractiveness of wealthier countries (with usually faster diffusion rates and larger market potential) may be mitigated by higher levels of competition (as a result of developed antitrust regulation and more consumer exposure to competitive marketing practices). From a policy point of view, it suggests that (in contrast to the conventional wisdom) simple deregulation may not be enough to reduce prices to competitive levels. In addition, a severe antitrust policy is crucial to achieve this goal.     

从“大萧条”看中美两国应对当前金融危机之策

本文站在历史的角度，审视与检讨中关两国政府在应对当前由次贷风暴引发的金融危机中的得与失。历史是一面镜子，发生在20世纪30年代的世界性大萧条与今日美国金融危机在很多方面具有相似之处。以史为鉴，在百年一遇的危机面前，各国政府应携手并进，同舟共济，避免陷入更深的困境。当前的局势为中国充分展示负责任大国的形象提供了契机。     

An analysis of EU wine trade: A gravity model approach

In this research study, a gravity model approach was used in order to analyze the main factors affecting the trade flows of wine in the EU. The empirical model was applied using data for the first twelve EU countries for the period 1989–97. It has been clearly shown in the empirical literature that gravity models can be successfully applied to a single commodity market. The present study utilized pooled cross-sectional and time series data in a one-way fixed effects model that accounted for country-pair heterogeneity. The results revealed that wine trade was positively influenced by an increase in GDP per capita, since greater income promotes trade. The remoteness of one country from another influenced exports positively and imports negatively, and the quantities traded did not prove to be very sensitive to wine prices. The depreciation of EU currencies and the high production of wine in the EU increased exports and reduced imports, while EU integration enhanced trade among members.     

己内酰胺浓缩工艺初探

文章通过对己内酰胺精制装置改扩建项目的对比分析,探讨改用“环己酮氨肟化技术”后,己内酰胺浓缩部分采用新工艺去杂的可能性,提出适合新技术条件下的己内酰胺浓缩工艺,并运用流程模拟软件“ASPEN”对新老工艺进行模拟计算,分析新工艺去除杂质的可行性。     

长沙市地下管线测量数字化的更新、软件升级及应用

地下管线的主要特点是隐蔽性,地下分布纵横交错,年代已久的原有手工数据几乎无参考价值且存档不便、使用复杂、工作量大。使用自主开发升级后的计算机程序软件,不仅可以大大提高地下管线测量数据的更新、规划设计及施工的效率,而且可以通过CAD图形分析对特殊地段重要管线是否保留利用作出决定。     

Are generalized call-spreads efficient?

In order to explain coexistence of a deductible for low values of the loss and an upper limit for high values of the loss in insurance contracts, we consider the exchange of risk between two rank dependent expected utility maximizers. It is shown that if the insurer (insured) takes more into account the lowest outcomes – hence maximal losses – than the insured (insurer), then the optimal contract has an upper limit (includes a deductible for high values of the loss). If furthermore, the insured (insurer) neglects the highest outcomes while the insurer (insured) does not, the optimal contract includes a deductible (full insurance) for low values of the loss.     

VMI模式下最优订货点的仿真研究

通过VMI模式下订货流程的模拟,根据客户订货前置期的历史统计数据或分布函数,利用Arena软件求解配送中心最优订货点。研究表明,仿真分析能获得比常规数学方法更科学合理的最优订货点。     

论以构建旅游形象为导向的城市景观规划设计——以广东肇庆市为例

高质量的城市景观规划设计对旅游形象的构建般城市景观规划设计在原理、方法上是相通的,但在城市总体形象定位、游客的需求、游赏行为、生态保护和城市景观的经济价值导向性作用下,有其自身的独特性.以广东肇庆市为例,阐释了以构建旅游形象为导向的城市景观规划设计的独特性.