解读杰克·韦尔奇

最近在各种场合听到不少企业家说要做中国的杰克·韦尔奇.这个话题很有意思.这种"朝圣"般的心情不难理解--被歌颂为"20世纪最伟大的职业经理人"的杰克·韦尔奇,的确是当代西方经理人的个中翘楚.     

城市商业中心地的形成与发展研究

在现实生活中,城市不同等级商业中心地的形成与发展主观上似乎遵循着某种规律,而客观上又呈现出无规则分布的特征.在城市不同等级商业中心地形成与发展过程中,有两个关键性因素,即交易成本和徒劳交易系数.这两个因素的变化情况,影响和制约了城市不同等级商业中心地的形成和发展.因此,在城市商业中心地的建设以及促进城市交易的活动过程中,节省交易成本支出、降低徒劳交易系数的制度安排、经营环境和信息流通空间就是非常重要的.     

改进后的PERT方法在进度风险分析中的应用

风险分析是进度控制中的重要内容。针对经典PERT网络的假设和计算过程,分析出它存在的三方面缺陷。并提出解决问题的三种具体措施,从概率论与数理统计的角度,对关键线路和关键工作进行了重新定义和确定的方法。     

烧结模糊控制系统的设计与实现

设计了一个烧结模糊控制系统，进而构建了一个基于模糊控制的自适应脉宽控制器，对煤气阀、换向阀开关时间进行控制；利用模糊控制器的模糊推理能力来实现煤气阀门开度在线调整，以达到优化控制的目的。运行结果表明，这种控制器与常规比值控制器相比可以取得较好的控制效果。     

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     

Contract modifications and the basis behavior of live cattle futures

The purpose of this study was to assess the basis behavior of the Live Cattle Futures contract at the Chicago Mercantile Exchange (CME) before and after the 1995 contract changes. Additionally, an alternative method of basis calculation utilizing weighted mean futures prices versus settlement futures prices was compared to determine which method provides a better representation of the basis level. Within a regression model with heteroskedascity error framework, we found that the level of nearby basis in the period after June 1995 has shifted lower and the average monthly open interest of net commercial long positions has substantially increased after the contract modifications. These empirical results are consistent with the notion that more long activity entered the market in response to the contract modifications. Additionally, an alternative (new) measure of basis calculation (cash price minus weighted mean futures price) produced similar results to two other commonly used measures. In conclusion, the 1995 contract changes have neither increased nor decreased the volatility of live cattle basis. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:557–590, 2004     

迷上酒吧的理由

有人比喻酒吧是水泥城市的天窗，“人们迫不及待地探出头，试图逃脱逼仄的空间，哪怕得到片刻的欢娱。”而在成都，在迷上——一个酒吧，富有想象力的名字将欢娱变成了前戏：人们夜夜笙歌，长久缠绵悱恻。[编者按]     

青岛，爱上你的N个理由

一月,青岛收到了2006年的第一份快乐和喜悦。在全国主流网络媒体新浪网的网络评选中,青岛,以绝对性的优势赢得广大网民心目中的“2005年度中国最具风情城市”。非官方的评比,没有专家团参与论证,甚至,没有严格的评选标准明细…… 100多万网民投票评选,足以证明它的分量。不靠宣传、不靠造势、不靠吹捧,一个城市用它的魅力感染着越来越多的人。不能不说这是一个城市最好的成绩单。青岛,有着让人们深深爱恋的N个理由。