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261.
以信息化带动勘察设计行业现代化,是勘察设计行业始终不渝的追求。"十一五"期间在中国勘察设计协会的领导下,行业单位的信息化工作取得了显著成绩。笔者结合近年来本单位的信息化工作实践以及行业会议和调研等行业信息化工作经历,对勘察设计单位"十一五"期间的信息化建设情况进行总结,并对"十二五"的发展思路提出相关建议。 相似文献
262.
Wave run-up on foundations is a very important factor in the design of entrance platforms for offshore wind turbines. When the Horns Reef 1 wind turbine park in Denmark was designed the vertical wave run-up phenomenon was not well known in the industry, hence not sufficiently considered in the design of Horns Reef 1. As a consequence damage was observed on the platforms. This has been the situation for several sites and design tools for platform loads are lacking. As a consequence a physical model test study was initiated at Aalborg University to clarify wave run-up on cylindrical piles for different values of diameter to water depth ratios (D/h) and different wave heights to water depth ratios (H/h) for both regular and irregular waves. A calculation model is calibrated based on stream function theory for crest kinematics and velocity head stagnation theory. Due to increased velocities close to the pile an empirical factor is included on the velocity head. The evaluation of the calculation model shows that an accurate design rule can be established even in breaking wave conditions. However, calibration of a load model showed that it was necessary to increase the run-up factor on the velocity head by 40% to take into account the underestimation of run-up for breaking or nearly breaking waves given that they produce thin run-up wedges and air entrainment, two factors not coped with by the measurement system. 相似文献
263.
A study on quantifying offshore pipeline resistance during vertical penetration and axial walking is presented, based on coupled pore pressure and displacement finite element analysis with the Modified Cam Clay model. Following the validation of the numerical method against published centrifuge test results and limit analysis solutions, we present the findings of a detailed parametric study on the response of partially-embedded pipelines under vertical and axial movements, employing 2-D plain strain and full 3-D soil–pipeline models. Emphasis is put on practical findings, and on proposing simplified expressions for the estimation of the contact enhancement factor and of the equivalent friction factor, that can be used at least for preliminary design purposes. 相似文献
264.
This paper presents a simple regression to predict settlement of a single floating pile supported by a homogeneous elastic soil and subjected to a vertical load. The regression, which is calibrated by a finite element model, allows the direct computation of the pile length required for serviceability limit state design of deep foundations. 相似文献
265.
贺盛瑜 《成都信息工程学院学报》1997,(2)
从软件工程学的角度出发,详细地分析了干部信息管理系统的需求并进行了设计;着重阐述了该系统的数据流图、数据词典以及系统的模块结构图 相似文献
266.
本文通过两个实例讨论水产试验设计的结果数据在SAS系统上实施统计分析的方法。实例一考察不同温度和盐度对鲻鱼总孵化百分率的影响的带有4个丢失单元的5×6因子设计,调用RSRES过程作二次响应曲面回归分析,结果表明当温度为27.04℃、盐度为31.95‰可获得最大总孵化百分率99.07%;实例二调用NLIN过程拟合罗氏沼虾的生长曲线,由SAS系统直接输出实测值对出生天数和预测值对出生天数的重迭散布图。 相似文献
267.
268.
The design of Human Occupied Vehicle (HOV) is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience dependence and improve the design, a new Multidisciplinary Design Optimization (MDO) method “Bi-Level Integrated System Collaborative Optimization (BLISCO)” is applied to the conceptual design of an HOV, which consists of hull module, resistance module, energy module, structure module, weight module, and the stability module. This design problem is defined by 21 design variables and 23 constraints, and its objective is to maximize the ratio of payload to weight. The results show that the general performance of the HOV can be greatly improved by BLISCO. 相似文献
269.
针对当前航海图书产品应用领域的不断拓展及其在不同应用领域的多样化需求,以及新的技术条件下海图制图手段的飞速发展,探讨了航海图书产品保障模式的转变,提出了构建面向知识层次的主动式保障模式的思想;从保障产品的多样性、快速保障的可行性以及远程保障的必要性等方面,研究了航海图书产品保障的发展趋势,为下一步海图制图与应用的发展提出了新的构想。 相似文献
270.
Nigel R. L. Gooding 《Marine Geodesy》2013,36(3-4):197-203
Abstract The historical development of positioning in relation to the nautical chart is described. Present nautical charts are largely based on geodetic surveys which date from the nineteenth and early twentieth centuries. This gave rise to the use of many local datums and there has been a need to provide the mariner with information to enable him to transfer his position from one chart to an adjacent one on a different datum. The availability of the Global Positioning System (GPS) and the World Geodetic System 1984 (WGS84) datum enables positioning on a single worldwide datum to become a reality. The important factors affecting the adoption of WGS84 as the datum for nautical charts—namely, data availability and the practical and political considerations—are discussed. New developments in the use of nautical charts, the electronic chart display and information systems, and the delineation of international boundaries and territorial limits all give rise to the requirement for improved positional accuracies. Recent experience in the use of GPS both in the provision of control for shore stations of electronic position‐fixing systems and the provision of position for hydrographic surveys is briefly discussed. 相似文献