Wave scattering by undulating bed topography in a two-layer ocean

The problem of wave scattering by undulating bed topography in a two-layer ocean is investigated on the basis of linear theory. In a two-layer fluid with the upper layer having a free surface, there exist two modes of waves propagating at both the free surface of the upper layer and the interface between the two layers. Due to a wave train of a particular mode incident on an obstacle which is bottom-standing on the lower layer, reflected and transmitted waves of both modes are created by the obstacle. For small undulations on the bottom of the lower layer, a perturbation method is employed to obtain first-order reflection and transmission coefficients of both modes for incident wave trains of again both modes in terms of integrals involving the bed-shape function. For sinusoidal undulations, numerical results are presented graphically to illustrate the energy transfer between the waves of different modes by the undulating bed. U. BASU was born in 1949. She is a professor in the Department Applied Mathematics, Calcutta University, India. Her current research interests include water wave problems, continuum mechanics, etc.     

BFS搜索策略在供电联锁装置中的应用研究

供电联锁装置是船舶供电系统安全运行的重要保障装置。随着船舶供电网络结构的日益复杂，如何识别当前网络结构成为供电联锁装置控制程序的设计关键。文章针对联锁装置网络识别的实际需求改进BFS策略并提出一种准确、有效、通用的网络结构识别算法，并将其应用到供电联锁装置中。联锁装置将采集到断路器状态转换为各个母线节点的邻居矩阵，以其作为算法的输入，将算法的输出矩阵转化结合联锁控制策略对每一个开关进行联锁、分断控制。通过软件仿真以及半实物测试实验测试算法程序的准确性。对于供电联锁装置，该方法可以解决复杂供电网络结构识别问题。     

Submerged Geosynthetic Reef as Shore Protection Measure for Islands

The Sagar Island, located north of the Bay of Bengal, intercepts the flow in the Hoogly estuary that comprises a network of several estuarine distributaries and...