在网络拍卖里(如eBay),有三种主要的交易制度,一是一口价,二是一般的拍卖,三是立即购买拍卖(auction with buy-it-now).本文利用一个简单的理论,说明这三种制度,其实是卖家在同一个最适化问题下的三种不同的解.换句话说,eBay里,卖家对...在网络拍卖里(如eBay),有三种主要的交易制度,一是一口价,二是一般的拍卖,三是立即购买拍卖(auction with buy-it-now).本文利用一个简单的理论,说明这三种制度,其实是卖家在同一个最适化问题下的三种不同的解.换句话说,eBay里,卖家对上述三种上架方式的策略选择,可以在一个统一的理论模型下去内生化(endogenize).其中的关键在于底价及立即购买价之间的相对关系,尤以底价的角色最重要.在这个理论下,本文证明这三种交易制度下的底价的相对大小,有一个固定的排序.我们利用eBay的iPod上架数据,来证实这个排序.展开更多
At present,the regular inspection of power poles is just a visual inspection based on the inspector’s experience.Thus,overlook of the deteriorated poles can come off.In order to avoid an accident due to the overlook ...At present,the regular inspection of power poles is just a visual inspection based on the inspector’s experience.Thus,overlook of the deteriorated poles can come off.In order to avoid an accident due to the overlook of the deteriorated poles,the authors propose a simple and easy health monitoring method for power poles using‘i Pod’.Since the applicability of‘i Pod’as a vibration sensor in this purpose was not clear,it was examined in the following procedure.First,the authors proposed a tool to fix the‘i Pod’to a power pole,and the performance of‘i Pod’as a vibration measurement device was compared with a conventional acceleration sensor.As a result,it was confirmed that‘i Pod’could give almost the same response with the conventional sensor in terms of the observed predominant frequency.Next,vibration measurements were conducted at power poles in a field.As a result,the observed predominant frequency corresponded to the calculated 2nd natural frequency of power poles.Although some power poles were supported by some additional wires from the ground,the measurements were successful at almost all the sites.Hence,the authors confirmed that the‘i Pod’based health monitoring is possible.展开更多
文摘在网络拍卖里(如eBay),有三种主要的交易制度,一是一口价,二是一般的拍卖,三是立即购买拍卖(auction with buy-it-now).本文利用一个简单的理论,说明这三种制度,其实是卖家在同一个最适化问题下的三种不同的解.换句话说,eBay里,卖家对上述三种上架方式的策略选择,可以在一个统一的理论模型下去内生化(endogenize).其中的关键在于底价及立即购买价之间的相对关系,尤以底价的角色最重要.在这个理论下,本文证明这三种交易制度下的底价的相对大小,有一个固定的排序.我们利用eBay的iPod上架数据,来证实这个排序.
基金The Electric Technology Research Foundation of Chugoku
文摘At present,the regular inspection of power poles is just a visual inspection based on the inspector’s experience.Thus,overlook of the deteriorated poles can come off.In order to avoid an accident due to the overlook of the deteriorated poles,the authors propose a simple and easy health monitoring method for power poles using‘i Pod’.Since the applicability of‘i Pod’as a vibration sensor in this purpose was not clear,it was examined in the following procedure.First,the authors proposed a tool to fix the‘i Pod’to a power pole,and the performance of‘i Pod’as a vibration measurement device was compared with a conventional acceleration sensor.As a result,it was confirmed that‘i Pod’could give almost the same response with the conventional sensor in terms of the observed predominant frequency.Next,vibration measurements were conducted at power poles in a field.As a result,the observed predominant frequency corresponded to the calculated 2nd natural frequency of power poles.Although some power poles were supported by some additional wires from the ground,the measurements were successful at almost all the sites.Hence,the authors confirmed that the‘i Pod’based health monitoring is possible.
