Study on short-range numerical forecasting of ocean current in the East China Sea Ⅱ. Three-dimensional diagnostic model and its application in the Bohai Sea

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Three-Dimensional Model Test for Port Engineering with Multi-Directional Waves

-The necessity of using irregular waves, especially multi- directional waves to conduct three-dimensional model tests for port engineering and the test method are described in this paper through an example of model test for a port. The test results show that a deep navigation channel has a large effect on the waves in front of the breakwater near the port entrance and on the wave condition in the port.     

Numerical Simulation of Saline Intrusion and Purging in Long Sea Outfalls with Three-Dimensional Model

1.IntroductionMarine sewage disposal has been applied widely in recent years.Saline intrusion into outfallsgreatly decreases the efficiency of such projects.Duringthe periods of lowdischarge,for example,atthe initial stage of operation of outfalls or at t…     

Wind influence on water exchange between the ria of Ferrol (NW Spain) and the shelf

The wind-induced water exchange between the ria of Ferrol (NW Spain) and the adjacent shelf is analyzed by means of a three-dimensional hydrodynamic model (MOHID2000). Since thermohaline measurements indicate that the estuary can be considered vertically homogeneous a barotropic version of the model has been used. Real in situ wind measurements have been used for model calibration and further analysis. The approach to study the wind effect on water exchange through the ria strait consisted in subtracting the signal calculated with only tidal forcing (T_s) from the one with wind and tidal forcing (WT_s). This shows the existence of a residual circulation, with water flowing in wind direction along surfaces layers and a counter current flowing in the opposite direction at bottom layers. The flux across the strait of Ferrol has shown to increase linearly on wind strength, with a correlation larger than 96% and reaching values close to 20 m³ s⁻¹ under real wind forcing.     

空间点集卷包裹算法的优化实现

凸包计算是计算几何研究中的基本问题之一 ,在许多领域均有应用。本文对求解空间点集凸包的卷包裹算法的实现问题进行了讨论。提出了 2点优化措施 ,并解决了实现中可能出现的共面点及由此带来的退化问题。     

基于旋翼无人机雷达的船只目标成像与类型识别研究进展综述

载有成像雷达的旋翼无人机具有成本低廉、对起降条件要求低、飞行姿态灵活多样等优点，可以在热点区域进行普查、详查或长时间悬停凝视等多模式成像监测，现已成为海上船只目标监测识别的重要手段。本文分别从旋翼无人机雷达硬件系统、无人机载雷达动目标成像、船只目标类型识别和目标三维结构特征提取等四方面开展国内外研究进展综述。总结分析发现当前利用旋翼无人机雷达进行船只目标成像和类型识别，尚存在运动船只成像散焦、三维结构重建难度大、类型识别精度低等问题，迫切需要推动相关技术的发展。     

基于等角度变比例投影的矿体轮廓线自动匹配方法研究

详细讨论了基于矿体轮廓线的三维建模方法中涉及的匹配对应、分支和构面建模等主要问题.针对轮廓线匹配问题提出了一种以矿体整体走向为投影方向,以相邻剖面中轮廓线总面积之比为缩放比例的等角度变比例投影算法,将不共面的轮廓线投影到同一平面中以完成共面轮廓线的匹配拓扑分析,从而解决轮廓线的对应问题.为了解决轮廓线的分支问题,设计了一种距离反比加权平均和样条函数相结合的自适应插值算法.最后通过采用实际矿山数据建模,对本文所提出的方法进行了有效性验证.     

Collapse loads for rectangular foundations by three-dimensional upper bound limit analysis using radial point interpolation method

A three-dimensional kinematic limit analysis approach based on the radial point interpolation method (RPIM) has been used to compute collapse loads for rectangular foundations. The analysis is based on the Mohr-Coulomb yield criterion and the associated flow rule. It is understood that the internal plastic power dissipation function and flow rule constraints can be expressed entirely in terms of plastic strain rates without involving stresses. The optimization problem has been solved on basis of the semidefinite programming (SDP) by using highly efficient primal-dual interior point solver MOSEK in MATLAB. The results have been presented in terms of the variation of the shape factors with changes in the aspect ratio (L/B) of the footing for different values of soil internal friction angle (ϕ). Computations have revealed that the shape factors, s_c and s_q, due to effects of cohesion and surcharge increase continuously with (1) decrease in L/B and (2) increase in ϕ. On the other hand, the shape factor s_γ, due to the effect of soil unit weight, increases very marginally with an increase in L/B up to (1) ϕ = 25° for a rough footing and (2) ϕ = 35° for a smooth footing. Thereafter, for greater values of ϕ, the variation of s_γ with L/B has been found to be quite similar to that of the factors s_c and s_q. The variations of (1) nodal velocity patterns, (2) plastic power dissipation, and (3) maximum plastic shear strain rates have also been examined to interpret the associated failure mechanism.     

地震效应下三维非均质土坡稳定性极限分析

基于极限分析上限定理,采用拟动力法研究了地震效应下非均质土坡的三维稳定性,并通过重度加大法（GIM）推导出边坡安全系数的显式表达式。此外,采用遗传算法进行优化,将所得结果进行对比验证,详细分析了地震条件下相关参数对边坡稳定性的影响。分析结果表明：边坡高度一定时,宽高比、边坡倾角的增大以及土体内摩擦角、非均质系数的减小均会造成安全系数的降低;拟静力法获得的结果相比于拟动力法较大,两种方法结果的差值会随着水平地震系数、有效内摩擦角的增大而增大,随着边坡倾角的增大而减小;土体放大系数的增大会导致安全系数减小,而地震波周期及波速的变化几乎对安全系数没有影响;滑动面轨迹受水平地震系数的影响较大,而受非均质系数的影响相对较小。     

云南普朗铜矿三维地质建模与深部找矿预测

云南普朗铜矿位于滇西北迪庆藏族自治州东部,已查明矿床铜金属量达大型规模,并具有超大型的远景。通过对普朗铜矿成矿地质背景的分析及基础地质资料的搜集,利用三维可视化建模技术构建普朗铜矿的三维地质模型,确定有利控矿要素并构建找矿预测模型。将证据权法与信息量法相结合进行综合成矿预测,最终圈定找矿靶区2处,为普朗铜矿的下一步找矿勘查工作提供参考。