鉴于可再生能源出力及负荷需求的不确定性会对配电网储能配置效果造成不利影响,该文构建了基于分类概率机会约束信息间隙决策理论(information gap decision theory,IGDT)的配电网储能鲁棒优化配置模型;该模型不仅利用IGDT提高了配置方...鉴于可再生能源出力及负荷需求的不确定性会对配电网储能配置效果造成不利影响,该文构建了基于分类概率机会约束信息间隙决策理论(information gap decision theory,IGDT)的配电网储能鲁棒优化配置模型;该模型不仅利用IGDT提高了配置方案的鲁棒性,还通过引入分类概率机会约束机制消除了常规IGDT需预先设定偏差因子的主观性,同时充分体现了风电、光伏和负荷不确定性分布的概率差异性。根据不确定理论将机会约束转化为等价确定性约束,并采用非劣排序复合微分进化,实现模型求解。算例应用表明,所提出的储能优化配置方法在经济性、电压改善效果、鲁棒性、灵活性和高效性等方面具有优越性。展开更多
提出了一种基于分布式群组移动的事件分类传输策略GMED(distributed group mobility adaptive event delivery).通过有效地发现和利用传感器节点在运动过程中形成的群组,建立基于群组的事件分类传输模型,改善数据传输性能.其中,群组的...提出了一种基于分布式群组移动的事件分类传输策略GMED(distributed group mobility adaptive event delivery).通过有效地发现和利用传感器节点在运动过程中形成的群组,建立基于群组的事件分类传输模型,改善数据传输性能.其中,群组的转发是依据各自与汇聚点的机会概率按照多副本方式进行的;而群内的事件传输则是基于各成员的稳定邻居集建立传输路径,并以单副本方式进行.队列管理则根据事件的优先级决定递交的顺序和丢弃原则.此外,引入冗余副本控制机制,优化副本管理,降低网络负载.模拟实验结果表明,与现有的几种DTMSN(delay tolerant mobile sensor networks)数据传输算法相比,GMED能以较低的数据传输能耗和传输延迟获得较高的数据传输成功率,且网络寿命相对较长.展开更多
The problem of the firm bankruptcy prediction was investigated by foreign researchers in the 1930s and it still remains relevant. Since the publishing of Altman＇s （1968） major work, based on multiple discriminant a...The problem of the firm bankruptcy prediction was investigated by foreign researchers in the 1930s and it still remains relevant. Since the publishing of Altman＇s （1968） major work, based on multiple discriminant analysis （MDA）, this methodological area has considerably changed. Taking into consideration that new data have appeared in the course of time, companies＇ average size has changed, and the accounting standards have changed （Altman, Haldeman, ＆ Narayanan, 1977）, methods and models should be renewed so as to be appropriate for current situation. The purpose of this paper1 is to reveal factors causing bankruptcy and use models appropriate for prediction bankruptcy in the area of a construction industry during the financial crisis. This investigation has been carried out on the basis of logit and probit analysis. The main reasons of bankruptcy revealed in the course of this investigation are the following： （1） non-optimal capital structure formation; （2） ineffective liquidity management; （3） decrease in assets profitability; and （4） decrease in short-term assets turnover. The most reliable indicators which give warning of bankruptcy ahead of others are financial instability and liquidity ratios.展开更多
文摘鉴于可再生能源出力及负荷需求的不确定性会对配电网储能配置效果造成不利影响,该文构建了基于分类概率机会约束信息间隙决策理论(information gap decision theory,IGDT)的配电网储能鲁棒优化配置模型;该模型不仅利用IGDT提高了配置方案的鲁棒性,还通过引入分类概率机会约束机制消除了常规IGDT需预先设定偏差因子的主观性,同时充分体现了风电、光伏和负荷不确定性分布的概率差异性。根据不确定理论将机会约束转化为等价确定性约束,并采用非劣排序复合微分进化,实现模型求解。算例应用表明,所提出的储能优化配置方法在经济性、电压改善效果、鲁棒性、灵活性和高效性等方面具有优越性。
文摘提出了一种基于分布式群组移动的事件分类传输策略GMED(distributed group mobility adaptive event delivery).通过有效地发现和利用传感器节点在运动过程中形成的群组,建立基于群组的事件分类传输模型,改善数据传输性能.其中,群组的转发是依据各自与汇聚点的机会概率按照多副本方式进行的;而群内的事件传输则是基于各成员的稳定邻居集建立传输路径,并以单副本方式进行.队列管理则根据事件的优先级决定递交的顺序和丢弃原则.此外,引入冗余副本控制机制,优化副本管理,降低网络负载.模拟实验结果表明,与现有的几种DTMSN(delay tolerant mobile sensor networks)数据传输算法相比,GMED能以较低的数据传输能耗和传输延迟获得较高的数据传输成功率,且网络寿命相对较长.
文摘The problem of the firm bankruptcy prediction was investigated by foreign researchers in the 1930s and it still remains relevant. Since the publishing of Altman＇s （1968） major work, based on multiple discriminant analysis （MDA）, this methodological area has considerably changed. Taking into consideration that new data have appeared in the course of time, companies＇ average size has changed, and the accounting standards have changed （Altman, Haldeman, ＆ Narayanan, 1977）, methods and models should be renewed so as to be appropriate for current situation. The purpose of this paper1 is to reveal factors causing bankruptcy and use models appropriate for prediction bankruptcy in the area of a construction industry during the financial crisis. This investigation has been carried out on the basis of logit and probit analysis. The main reasons of bankruptcy revealed in the course of this investigation are the following： （1） non-optimal capital structure formation; （2） ineffective liquidity management; （3） decrease in assets profitability; and （4） decrease in short-term assets turnover. The most reliable indicators which give warning of bankruptcy ahead of others are financial instability and liquidity ratios.
