基于人工神经网络的地铁施工招标综合评估模型

广州地铁工程是国内数个重要的大型城市基础建设项目之一。目前对于这种复杂的大型工程项目,迫切需要一个成熟可靠的公开招标评估系统。根据广州地铁工程的实际招标评标数据,提出应用人工神经网络(ANN)建立地铁施工招标综合评估模型。BP神经网络具有很强的自学习和自适应能力,可以精确地迫近复杂的非线性动态函数。经过训练网络,基于BP网络的模型成功量化了主观和定性的技术评估指数,得出较满意的评估结果。该模型可以通过增加样本提高精度,从而应用在地铁和其他类似建设项目招标中。     

A theoretical framework to evaluate different margin‐setting methodologies

The margin system is the first line of defense against the default risk of a clearinghouse. From the perspectives of a clearinghouse, the utmost concern is to have a prudential system to control the default exposure. Once the level of prudentiality is set, the next concern will be the opportunity cost of the investors, because high opportunity cost discourages people from hedging futures, and thus defeats the function of a futures market. In this article, we first develop different measures of prudentiality and opportunity cost. We then formulate a statistical framework to evaluate different margin‐setting methodologies, all of which strike a balance between prudentiality and opportunity cost. Three margin‐setting methodologies, namely, (1) using simple moving averages; (2) using exponentially weighted moving averages; (3) using a GARCH approach, are applied to the Hang Seng Index futures. Keeping the same prudentiality level, it is shown that the one using a GARCH approach by and large gives the lowest average overcharge. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:117–145, 2004     

The index futures markets: Is screen trading more efficient?

This article uses a nonparametric test based on the arc‐sine law (see, e.g., Feller, 1965 ), which involves comparing the theoretical distribution implied by an intraday random walk with the empirical frequency distribution of the daily high/low times, in order to address the question of whether the abandonment of pit trading has been associated with greater market efficiency. If market inefficiencies result from flaws in the market microstructure of pit trading, they ought to have been eliminated by the introduction of screen trading. If, on the other hand, the inefficiencies are a reflection of investor psychology, they are likely to have survived, unaffected by the changeover. We focus here on four cases. Both the FTSE‐100 and CAC‐40 index futures contracts were originally traded by open outcry and have moved over to electronic trading in recent years, so that we are able to compare pricing behavior before and after the changeover. The equivalent contracts in Germany and Korea, on the other hand, have been traded electronically ever since their inception. Our results overwhelmingly reject the random‐walk hypothesis both for open‐outcry and electronic‐trading data sets, suggesting there has been no increase in efficiency as a result of the introduction of screen trading. One possible explanation consistent with our results would be that the index futures market is characterized by intraday overreaction. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:337–357, 2004     

An empirical analysis of the relationship between the hedge ratio and hedging horizon: A simultaneous estimation of the short‐ and long‐run hedge ratios

This article analyzes the effects of the length of hedging horizon on the optimal hedge ratio and hedging effectiveness using 9 different hedging horizons and 25 different commodities. We discuss the concept of short‐ and long‐run hedge ratios and propose a technique to simultaneously estimate them. The empirical results indicate that the short‐run hedge ratios are significantly less than 1 and increase with the length of hedging horizon. We also find that hedging effectiveness increases with the length of hedging horizon. However, the long‐run hedge ratio is found to be close to the naïve hedge ratio of unity. This implies that, if the hedging horizon is long, then the naïve hedge ratio is close to the optimum hedge ratio. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:359–386, 2004     

QUADRATIC TERM STRUCTURE MODELS FOR RISK-FREE AND DEFAULTABLE RATES

In this paper, quadratic term structure models (QTSMs) are analyzed and characterized in a general Markovian setting. The primary motivation for this work is to find a useful extension of the traditional QTSM, which is based on an Ornstein–Uhlenbeck (OU) state process, while maintaining the analytical tractability of the model. To accomplish this, the class of quadratic processes, consisting of those Markov state processes that yield QTSM, is introduced. The main result states that OU processes are the only conservative quadratic processes. In general, however, a quadratic potential can be added to allow QTSMs to model default risk. It is further shown that the exponent functions that are inherent in the definition of the quadratic property can be determined by a system of Riccati equations with a unique admissible parameter set. The implications of these results for modeling the term structure of risk-free and defaultable rates are discussed.     

中国企业到美国跨国并购的方法与技巧(上)

中国企业到美国跨国并购成了国际媒体热门话题。但怎样并购、如何规避并购风险等问题，中国企业却心中无数。如何提高跨国并购的成功率，是摆在中国企业面前的一道难题。本文主要论述中国企业到美国跨国并购的具体操作方法和技巧。     

双旋Y切石英振子厚度模式的频温特性的研究

本文利用描述固体中弹性声波的克里斯托费尔方程,建立了双旋Y切石英振子厚度模式的频温特性分析方法,并编制了相应的计算机程序。该程序可给出双旋Y切石英振子在任意切角(ф_3ф_1)下的厚度模(a、b、c模)的频率温度特性曲线。文中给出了单旋AT切、BT切(b模)、双旋SC切(b、c模)、FC切、IT切、LC切、NL_1切、NL_2切、AK切等各已知切型的频温特性曲线。对石英谐振器的切角灵敏度和切角误差进行了分析。     

外贸服务公司如何开展质量管理体系审核

旧版（９４版）IS０９００１标准采用的结构是供方产品质量环形成的２０个要素的编排方式，强调体系要素对应的符合性。服务业实施此标准，对某些要素不好把握。２０００版IS０９００１标准以“过程方式”为基础构架了质量管理体系，引导组织以满足顾客要求和符合法律法规为基本出发点，把PDCA循环融入每一个过程的管理之中，适合了服务业产品／服务的提供过程。我国在加入WTO三年后，外贸将放开经营，实施登记许可制度。因此随着外贸垄断格局的进一步打破，专业外贸公司在融资能力、专业人才等方面的优势不复存在。上述的外因、内因使…     

在虚拟的刀光剑影中游走

阴霾的天气容易让人想不开，城市的纷乱，多少有些无奈。而有些人可以抛弃环境的影响，逃遁或者投入到美妙的图景中。     

国有商业银行经营发展战略思考

中国加入WTO后,金融业特别是银行业所面临的经营环境将发生很大变化,国有商业银行如何改进自身经营存在的问题,不断地适应经营环境的变化,在与外资银行前所未有的竞争中求得生存与发展,是我们必须面对与认真思考的问题,本文试从国有商业银行经营组织架构、经营规模、经营范围及经营体制等方面来探讨相关问题。 一、经营组织架构——从行政区域分支行架构模式到扁平化架构模式