基于港口船舶识别的高分二号卫星遥感影像融合方法比较          下载免费PDF全文

赵益智  朱海天  李修楠  杨劲松  陈鹏 《海洋学研究》2022,40(4):90-96

在卫星遥感影像识别中,相较于海上单一环境的船舶识别,港口船舶识别由于存在集装箱、码头等大量干扰目标,显得更为困难。采用强度-色度-饱和度(Intensity-Hue-Saturation,IHS)变换、Brovey变换(Brovey Transform,BT)、ESRI全色锐化变换、简单均值变换和施密特正交变换法(Gram-Schmidt,GS)等5种融合算法,进行高分二号卫星全色和多光谱影像的融合试验,通过定性和定量评价选出适用于港口船舶影像的最优方法。结果显示GS融合方法在增加影像空间信息的同时维持了光谱保真性,其均方根误差、峰值信噪比、结构相似性等指标均优于其他4种融合方法,可用于港口船舶识别。  相似文献   

Risk assessment on a pipeline passing through a ship mooring area     

闫澍旺  霍知亮  孙立强  刘润 《中国海洋工程》2014,28(2):207-214

It is very common that a submarine pipeline has to pass through a ship mooring area near a harbor zone in the Bohai Bay, China. The risk assessment of accidental events induced by the potential anchoring ships is carried out, which will lead to external interference with the pipeline. A procedure to calculate the probability for the anchoring activity in the ship mooring area to damage the underlying pipeline is proposed. The adopted methodology is based on the recommendations suggested by the DNV Codes. The same philosophy is also applied to estimate the damage probability that is concerned with sinking ships.  相似文献   

Hydrodynamic characteristics of ship sections in shallow water with complex bottom geometry     

S. Sutulo 《Ocean Engineering》2010,37(10):947-958

The method of boundary integral equation developed by the authors was applied for computing inertial and damping characteristics of ship sections for the cases of multi-stepped and inclined bottoms. Comparative calculations for three typical ship hull sections were performed and analyzed. The frequency-dependent data computed for these ship sections can be used to assess the bottom geometry's influence onto the ship motions in waves by means of the strip theory. Limiting values of the same characteristics corresponding to the close-to-zero frequency can also be used for estimation of hydrodynamic forces in manoeuvring over shallow and confined waterways.  相似文献   

我国实施大洋钻探工程的初步设想          下载免费PDF全文

叶建良  张伟  谢文卫 《探矿工程》2019,46(2):1-8

约占地球面积71%的海洋里蕴藏着海量的地质、生物、气候等信息和丰富的资源,我国“十三五”国家科技创新规划中,将“深海、深地、深空、深蓝科学研究”列为战略性前瞻性重大科学问题,并将“国际大洋发现计划（IODP）列为5项国际大科学计划和大科学工程之一。但在深海钻探,作业环境和条件都较陆地上更加复杂,对钻探船、钻探工艺、环保措施、施工组织管理等都是严峻的考验。本文在概述大洋钻探的意义和成果,回顾世界大洋钻探的演进史和工程实施概况以及我国参加大洋钻探情况的基础上,针对大洋钻探的钻井特点和地层条件,探讨了海洋科学钻探取心技术、超深水条件的重入钻孔技术、跟管钻进下套管技术、超深水条件的泥浆循环等关键技术问题,提出了我国实施大洋钻探工程的初步设想。  相似文献   

Assessing the accuracy of thin ice thickness retrieval by Arctic ship observations          下载免费PDF全文

Ma Xueyi  Zhao Xi  Qu Meng  Cheng Zian 《极地研究》1988,31(4):431

  相似文献   

Predicting Global Seafloor Topography Using Multi-Source Data     

Min zhang Hu  Jian cheng Li  Hui Li  Chong Yang Shen  Tao yong Jin  Le lin Xing 《Marine Geodesy》2013,36(2):176-189

A new one-minute global seafloor topography model was derived from vertical gravity gradient anomalies (VGG), altimetric gravity anomalies, and ship soundings. Ship soundings are used to constrain seafloor topography at wavelengths longer than 200 km and to calibrate the topography to VGG (or gravity) ratios at short wavelengths area by area. VGG ratios are used to predict seafloor topography for wavelength bands of 100–200 km and to suppress the effect of crust isostasy. Gravity anomalies are used to recover seafloor topography at wavelengths shorter than 100 km. The data processing procedure is described in detail in this paper. The accuracy of the model is evaluated using ship soundings and existing models, including General Bathymetric Charts of the Oceans (GEBCO), DTU10, ETOPO1, and SIO V15.1. The results show that, in the discussed regions, the accuracy of the model is better than ETOPO1, GEBCO, and DTU10. Additionally, the model is comparable with V15.1, which is generally believed to have the highest accuracy. In the north-central Pacific Ocean, the accuracy of the model increased by approximately 29.5% compared with the V15.1 model. This indicates that a more accurate seafloor topography model can be formed by combining gravity anomalies, VGG, and ship soundings.  相似文献   

MOSES软件在系泊浮体运动计算中的应用研究     

李怀亮  徐慧  谢维维  董璐  高巍 《海洋工程》2013,31(6):16-21

采用MOSES软件计算某起重船迎浪下的水动力性能和运动响应,并对该船进行缩尺比为1:50的模型试验。通过软件计算结果和试验结果的对比,分析计算模型的网格划分、二阶波浪力计算方法和粘性阻尼等关键参数的选取对MOSES计算系泊浮体运动的影响,为MOSES软件在系泊下运动计算方面提出建议。  相似文献   

Buckling and postbuckling of composite ship panels stiffened with preform frames     

Sarah E. Mouring 《Ocean Engineering》1999,26(8):793

The U.S. shipbuilding industry recently has started incorporating composite materials in the construction of both military and commercial ships due to the advantages of composite construction. These advantages include the reduction in total life costs, corrosion resistance, high strength- and stiffness-to-weight ratios, and improved stealth for military applications. One disadvantage is the higher costs of composites compared to steel and other conventional materials. Therefore, new higher quality materials with lower costs and new fabrication methods need to be developed before composite materials will be fully accepted for the construction of large ships. A new composite preform framing technology shows promise in the reduction of fabrication costs for large ship construction. There already has been significant cost savings using this framing technology in the construction of small recreational boats and large yachts. This framing technology involves casting a dry glass fiber-reinforced plastic (GRP) fabric into shape in a closed mold with a foam core. One unresolved issue using this framing technology is the orientation of the fiber for the frames. This paper summarizes experimental results of the testing of composite panels stiffened with preform frames under in-plane uniaxial compressive loads. Biaxial (0,90), quadaxial (0,90,+45,−45), and triaxial (+45,−45,0) laminates were used in the frames.  相似文献   

承船厢吊耳的局部应力分析研究   总被引：1，自引：0，他引：1  

张世联  徐汉涛  杨文华  韦疑男 《海洋工程》1999,17(3)

承船厢是升船机系统中的一个重要结构物,该结构物中的关键结构吊耳是否有足够的强度,应力分布是否合理将直接影响升船机系统工作的可靠性。在对吊耳进行光弹性试验基础上,对吊耳的光弹性模型进行有限元分析,通过结果的分析比较,确定承船厢吊耳的局部结构的计算可靠程度  相似文献   

非通航孔桥墩自适应拦截网防撞装置实船拦截试验与水动力计算   总被引：1，自引：0，他引：1       下载免费PDF全文

王贝壳  陈涛  杨黎明  刘军  董新龙  周风华  王永刚 《海洋工程》2017,35(1):90-96

针对非通航孔桥墩,研发了一种自适应拦截网防船舶撞击装置,主要由系泊大浮体、系泊锚链和固定锚、自适应小浮筒、拦截网、恒阻力缆绳以及触发钢索所组成。阐述了该防撞装置设计原理,即偏航船舶撞击该防撞装置,小浮筒会带动拦截网自适应地从水平状态竖起展开,包裹住来撞船首,再通过相连浮体的运动阻力和恒阻力缆绳来吸收船舶动能,拦截住船舶,保护非通航孔桥墩安全。随后介绍在福建平潭海峡大桥引桥附近海域实施的实船撞击自适应拦截网防撞装置的大型试验,试验结果显示:自适应拦截网成功升起,船舶被安全拦截,从而实验证实了设计原理与设计方案的可行性和可靠性。最后,采用大型水动力分析软件AQWA对防撞装置拦截船舶过程进行数值模拟,模拟结果与实验结果基本一致,说明了数值仿真具有较好的计算精度和可靠性,能够为该防撞装置的结构设计与优化提供重要的参考。  相似文献