关于抗撞桥墩设计与计算问题

分析了影响河道发生事故的概率和损坏桥梁概率的各种因素，给出概率的数学模型以判断桥梁在该河道上发生碰撞的可能性，其次，对影响船舶撞击力的因素：船舶撞击能量，标准船舶的选择，撞击力，撞击力作用点及撞击速度等进行了分析和讨论，给出了撞击力的计算方法，同时对，如何增强桥梁自身的防撞能力和采取的防撞措施进行了具体建议。     

船舶外加电流阴极保护用辅助阳极组件

阴极保护和优质涂层相结合是防止海水中金属结构物腐蚀的有效方法。在船舶外加电流阴极保护系统中 ,辅助阳极组件是其中的关键组成部分。介绍了船舶外加电流阴极保护用辅助阳极组件的研究发展及工程经验 ,评述了铅银阳极、铂阳极和混合金属氧化物阳极的性能特点。     

An integrated approach to hydrogen economy in Sicilian islands

CNR–ITAE is developing several hydrogen and fuel cell demonstration and research projects, each intended to be part of a larger strategy for hydrogen communities settling in small Sicilian islands. These projects involve vehicle design, hydrogen production from renewable energy sources and methane, as well as implementation strategies to develop a hydrogen and renewable energy economy. These zero emission lightweight vehicles feature regenerative braking and advanced power electronics to increase efficiency. Moreover, to achieve a very easy-to-use technology, a very simple interface between driver and the system is under development, including fault-recovery strategies and GPS positioning for car-rental fleets. Also marine applications have been included, with tests on PEFC applied on passenger ships and luxury yacht as power system for on-board loads. In marine application, it is under study also an electrolysis hydrogen generator system using seawater as hydrogen carrier. For stationary and automotive applications, the project includes a hydrogen refuelling station powered by renewable energy (wind or/and solar) and test on fuel processors fed with methane, in order to make the power generation self-sufficient, as well as to test the technology and increase public awareness toward clean energy sources.     

多孔钢板在双轴受压与边缘剪力荷载共同作用下的极限强度

作为作者系列研究成果[Paik J K．Ultimate strength of perforated steel plates under edge shear loading．Thin-Walled Structures，2007，45：301-6，Paik J K．Ultimate strength of perforated steel plates under axial compressive loading along short edges．Ships Offshore Struct，2007，2（3）：（inpress）]的终结篇，与前期论文在边缘剪力或单轴压力荷载方面进行了对比，目的是研究双轴受压和边缘剪力作用下多孔钢板的极限强度特点，这是船舶和船舶型海洋结构在货物和水压作用下的一个典型受力模式。板的约束考虑为四边简支，中心区域为圆形孔。一系列ANSYS非线性有限元分析中考虑了不同的板尺寸（厚度）。在有限元分析基础上，推导出组合荷载下多孔板的极限强度交互关系公式，可用于可靠性分析或规范中极限强度的预测。     

国外舰用柴油机的发展及启示

论述了柴油机在舰船动力中的重要地位,分析了国外舰船动力装置发展趋势、国外舰用柴油机技术水平及发展趋势;提出了有关提高我国柴油机整体技术水平的建议;最后,阐述了国外舰用柴油机发展给我们带来的启示,提出了我国舰用柴油机需要突破的关键技术及应采取的技术措施。     

Ultimate strength of perforated steel plates under edge shear loading

The aim of the present study is to investigate the ultimate strength characteristics of perforated steel plates under edge shear loading, which is a primary action type arising from cargo weight and water pressure in ships and ship-shaped offshore structures. The plates are considered to be simply supported along all (four) edges and kept straight. The cutout is circular and located at the center of the plate. A series of ANSYS nonlinear finite element analyses (FEA) are undertaken with varying the cutout size (diameter) as well as plate dimensions (plate aspect ratio and thickness). By the regression analysis of the FEA results obtained, a closed-form empirical formula for predicting the ultimate shear strength of perforated plates, which can be useful for first-cut strength estimations in reliability analyses or code calibrations, is derived. The accuracy of the ultimate strength formula developed is verified by a comparison with more refined nonlinear FEA results.     

基于SAR子孔径序列图像配准的海洋动态信息获取

合成孔径雷达(SAR)在海洋遥感中发挥着重要的作用。海洋的动态信息如洋流的运动和海浪的传播等是海洋信息中的重要组成部分。但是通常的SAR海洋图像信息处理是将SAR图像作为海面的瞬时状态进行处理,无法获取海洋的动态信息。该文采用子孔径分割的方法获取海面的具有连续时间间隔的序列图像,通过改进的相位相关法对序列图像间的对应部分进行亚像素级配准,获取了海面各个部分的海浪纹理信息运动的速度大小和方向。仿真实验表明改进的配准方法具有1/10像素精度和极强的噪声鲁棒性。对序列图像间相同的舰船目标,分别采用该文提出的配准法与较成熟的"尾迹法"计算的舰船速度基本一致,证明了该文方法的有效性。     

Idealisation of ships with large hatch openings by a thin-walled rod of open section on many elastic supports

The open part of the ship's hull with large hatch openings is considered as a prismatic thin-walled rod of open section on many elastic supports subjected to torsion. The stiffness of deck strips and the ship's sides in the deck plane is taken into account by elastic supports. Internal forces and displacements of the open part of the hull and deck strips are obtained in an analytical form, using the method of initial parameters. Stresses and displacements can be presented numerically and graphically, in a form suitable for preliminary calculations. A numerical example is given.     

Blind separation of partially overlapping data packets

The paper discusses the separation of partially overlapping data packets by an antenna array in narrowband communication systems. This problem occurs in asynchronous communication systems and several transponder systems such as Radio Frequency Identification (RFID) for wireless tags, Automatic Identification System (AIS) for ships, and Secondary Surveillance Radar (SSR) and Automatic Dependent Surveillance—Broadcast (ADS—B) for aircraft. Partially overlapping data packages also occur as inter-cell interference in mutually unsynchronized communication systems. Arbitrary arrival times of the overlapping packets cause nonstationary scenarios and makes it difficult to identify the signals using standard blind beamforming techniques. After selecting an observation interval, we propose subspace-based algorithms to suppress partially present (interfering) packets, as a preprocessing step for existing blind beamforming algorithms that assume stationary (fully overlapping) sources. The proposed algorithms are based on a subspace intersection, computed using a generalized singular value decomposition (GSVD) or a generalized eigenvalue decomposition (GEVD). In the second part of the paper, the algorithm is refined using a recently developed subspace estimation tool, the Signed URV algorithm, which is closely related to the GSVD but can be computed non-iteratively and allows for efficient subspace tracking. Simulation results show that the proposed algorithms significantly improve the performance of classical algorithms designed for block stationary scenarios in cases where asynchronous co-channel interference is present. An example on experimental data from the AIS ship transponder system confirms the effectiveness of the proposed algorithms in a real application.     

A study on the modeling of transitional lateral force acting on the berthing ship by CFD

To evaluate the unsteady motion in laterally berthing maneuver, it is necessary to estimate clearly the magnitudes and properties of hydrodynamic forces acting on ship hull in shallow water. A numerical simulation has been performed to investigate quantitatively the hydrodynamic force according to water depth for Wigley model using the CFD (Computational Fluid Dynamics) technique. By comparing the computational results with the experimental ones, the validity of the CFD method was verified. The numerical solutions successfully captured some features of transient flow around the berthing ship. The transitional lateral force in a state ranging from the rest to the uniform motion is modeled by using the concept of circulation.