Learning cycles in Bertrand competition with differentiated commodities and competing learning rules

This paper stresses the importance of heterogeneity in learning. We consider a Bertrand oligopoly with firms using either least squares learning or gradient learning for determining the price. We demonstrate that convergence properties of the rules are strongly affected by heterogeneity. In particular, gradient learning may become unstable as the number of gradient learners increases. Endogenous choice between the learning rules may induce cyclical switching. Stable gradient learning gives higher average profit than least squares learning, making firms switch to gradient learning. This can destabilize gradient learning which, because of decreasing profits, makes firms switch back to least squares learning.     

OPPC在220kV线路的应用与分裂导线的粘连问题

光纤复合相线（Optical Phase Conductor,OPPC）,是在传统的相线结构中嵌入光纤单元的一种新型特种光缆。用OPPC代替三相中的一相,解决电网通信问题,OPPC在220kV及以上线路中应用时,可以通过多种方式避免分裂导线互相粘连的问题。文章通过分析分裂导线粘连的原因并对比各种解决方法的优劣,给出工程应用当中的建议,对指导日后工程具有积极的贡献。     

基于景观生态安全格局的泥石流多发城镇防灾、减灾体系构建--以昆明市东川区为例

通过对泥石流灾害形成原因及对城镇造成危害的调查分析,提出泥石流多发城镇的灾害防御应首先从土地资源的保护和利用以及景观的战略布局着手,在城市避难疏散系统的构建中统筹兼顾各类城市灾害的危害性.采取灾害测报系统及布局、生命线保障系统规划,救灾设施及布局、抗灾防灾工程建设和疏散及避难通道规划等五项工程性措施,通过防灾救灾组织指挥体系建设、救灾队伍建设、灾害应急预案的制定、防灾救灾的宣传教育和灾害政策法规建设等五项非工程性措施的支撑,从根本上达到防灾减灾的目标,构建生态安全的城市.