公路软基沉降函数干涉神经网络预测模型   总被引：3，自引：0，他引：3  

樊琨  杨涛  李国维 《岩土力学》2004,25(2):301-303

建立了基于函数干涉神经网络的公路软基沉降预测模型。工程实例表明,所建议的模型外延性好,而且,可以由较短预压期内沉降观测资料预测远期沉降发展,与传统沉降预测模型相比具有显著的优越性,工程应用前景广阔。  相似文献   

Observed characteristics of flow,water mass,and turbulent mixing in the Preparis Channel     

Ruijie Ye  Feng Zhou  Xiao Ma  Dingyong Zeng  Feilong Lin  Hongliang Li  Chenggang Liu  Soe Moe Lwin  Hlaing Swe Win  Soe Pyae Aung 《海洋学报(英文版)》2023,42(2):83-93

Preparis Channel is the very important exchange path of energy and materials between the northern Bay of Bengal and Andaman Sea(AS). A set of hydrographic measurements, a microstructure profiler, and a deep mooring were used to determine the characteristics of water masses, turbulent mixing, and flows in the Preparis Channel. The unprecedented short-term mooring data reveal that a deep current in the deep narrow passage(below 400 m) of the Preparis Channel flows toward the Bay of Bengal(BoB) wit...  相似文献   

Investigation of exhaust gas dispersion in the near-wake region of a light-duty vehicle     

Hong-di?He  Wei?Shi  Wei-Zhen?LuEmail author 《Stochastic Environmental Research and Risk Assessment (SERRA)》2017,31(3):775-783

The air pollution induced by urban traffic has addressed much attention in recent years as the rapid urbanization and the fast increase of vehicle number in urban area. In this study, we attempted to investigate the dispersion behavior of exhaust gas from exhaust pipe using computational fluid dynamics approach. The time-averaged CO₂ concentration, velocity and temperature profiles along the centerline of the vehicular exhaust plume were simulated in varied situations. The computational results showed good agreement with the experimental data and the numerical model was validated to be an effective method to investigate the pollutant dispersion in the near-wake region of a vehicle. Based on it, the numerical simulations were extended to explore the impacts of the emit concentration, the emit direction and the incoming velocity on the flow dynamics and CO₂ dispersion. The outputs indicated that the emit concentration could change the pollution level in the near-wake region of a vehicle and the emit direction may alter the spreading direction of the vehicular exhaust plume. The incoming velocity was found to have dominant influence on the dispersion of pollutant due to induced vortices and turbulence behind the vehicle. These findings are expected to provide important insight into evaluating the design and control strategies for alleviating mobile source emissions.  相似文献   

赤道印度洋上层环流辐合辐散的年际变异成因分析     

陈瑞莹  何卓琪  王卫强  高郭平 《海洋与湖沼》2019,50(4):765-776

印度洋上层海气相互作用对印度洋和太平洋气候系统有重要影响。目前针对印度洋气候态环流特征已有较为全面的研究,但针对印度洋环流的年际变化及其季节性差异的特征分析和具体作用机制,仍缺乏深入的研究。本文利用1979—2007年Simple Ocean Data Assimilation(SODA)再分析资料研究了赤道印度洋表层辐合辐散的年际变异及其季节依赖性。结果表明,以赤道为中心,印度洋上层异常海流,在经向上形成显著的辐合(辐散)现象,究其原因主要是赤道纬向风异常形成的Ekman流所导致。进一步分析表明,热带印度洋异常纬向风的成因与太平洋-印度洋的热力强迫过程作用有关,并且不同的热力强迫过程呈现出显著的季节差异性。此热力强迫过程,具体可分为3种类型:第一类是太平洋纬向海表热力差异的遥强迫作用,主要发生在冬末春初,热带太平洋的纬向热力差异通过调节Walker环流,在印度洋激发出一个异常的次级环流,对应的大气低层形成纬向风异常;第二类是东-西印度洋海表热力差异的局地强迫作用导致的局地环流,使赤道印度洋上空形成纬向风异常,此过程在春末夏初较为显著;第三类是太平洋-印度洋热力差协同作用的结果,使赤道印度洋盛行异常的纬向风,此过程在秋季起主导作用。  相似文献   

上海外高桥港区停泊船聚类分析与异常检测     

郑海林  胡勤友  杨春  陈金海  梅强 《地球信息科学学报》2018,20(5):640-646

停泊船空间分布规律挖掘,在海事监管、港口管理和航运公司船队管理方面有着重要意义。现有研究主要针对船舶停泊点进行空间聚类以识别码头和锚地,缺乏对码头、锚地内船舶停泊特征分析,及码头和锚地外的异常停船的检测。因此,利用海量船舶自动识别系统（AIS）数据探索船舶停泊规律显得很有必要,且具备可行性。根据海况设定停泊速度阈值和停泊位置变化量阈值,建立停船判定模型。按港区、船型筛选,获取2016年1至11月外高桥港区集装箱船停泊记录。根据类中心点密度和聚类数量,设定邻域半径（ε）和邻域密度（MinPts）,采用密度聚类（DBSCAN）算法对船舶停泊点进行密度聚类,并将聚类结果与外高桥港区码头、锚地分布图进行比较,生成可疑停船列表。对比船舶历史轨迹,明确可疑停船列表中船舶真实停泊记录,筛选出异常停船。研究发现,2016年1至11月外高桥港区船舶异常停泊点位于圆圆沙锚地至吴淞口锚地间的南港水道和江亚南沙锚地附近的南港水道航段。船舶停泊前、后位置变化幅度小,而速度变化幅度大,推测船舶突发故障是其异常停泊的原因。海事主管部门（MSA）可根据船舶水上移动通信业务识别码（MMSI）快速锁定航运公司,加强岸上船舶安全管理。船舶停泊位置和时间能够记录船舶发生故障地点及其持续时间,为船队管理提供重要依据。  相似文献   

Impact of narrow plates on broader liquid bodies     

《Applied Ocean Research》2019

Analytical leading-order solutions are given for liquid bodies that hit a rigid plate in impulsive incompressible impact. The liquid bodies are broader than the impacting plate which causes a mixed boundary condition. The initial velocity field, the corresponding pressure impulse field, and the associated virtual masses are calculated. The following liquid body geometries are studied: 2D rectangles hit symmetrically by the plate, including a case with impermeable sidewalls, asymmetric hit of a 2D rectangle, and symmetric hit of a 3D rectangular box, and of a circular cylinder. A plausible estimate for liquid impact is that a marine structure can never be struck by a greater force impulse than the momentum of incoming liquid perpendicular to its own cross section. By comparing the virtual mass with the total projected fluid mass above the plate for the different liquid body geometries, it is found that the estimate holds for all the computed cases.  相似文献   

Particle Swarm-Based Translation Control for Immersed Tunnel Element in the Hong Kong–Zhuhai–Macao Bridge Project     

Jun-jun Li  Xiao-jun Yang  Ying-jie Xiao  Bo-wei Xu  Hua-feng Wu 《中国海洋工程》2018,32(1):32-40

Immersed tunnel is an important part of the Hong Kong–Zhuhai–Macao Bridge(HZMB) project. In immersed tunnel floating, translation which includes straight and transverse movements is the main working mode. To decide the magnitude and direction of the towing force for each tug, a particle swarm-based translation control method is presented for non-power immersed tunnel element. A sort of linear weighted logarithmic function is exploited to avoid weak subgoals. In simulation, the particle swarm-based control method is evaluated and compared with traditional empirical method in the case of the HZMB project. Simulation results show that the presented method delivers performance improvement in terms of the enhanced surplus towing force.  相似文献   

Dynamic Response of 6MW Spar Type Floating Offshore Wind Turbine by Experiment and Numerical Analyses     

Meng  Long  He  Yan-ping  Zhao  Yong-sheng  Yang  Jie  Yang  He  Han  Zhao-long  Yu  Long  Mao  Wen-gang  Du  Wei-kang 《中国海洋工程》2020,34(5):608-620

China Ocean Engineering - The floating offshore wind turbine (FOWT) is widely used for harvesting marine wind energy. Its dynamic responses under offshore wind and wave environment provide...  相似文献   

视频影像增强虚拟三维场景的注册与渲染方法研究   总被引：1，自引：1，他引：0  

周凡 《测绘学报》2019,48(6):801-801

  相似文献   

Energy saving performance analysis of contra-rotating azimuth propulsor. Part 2: Optimal matching investigation in model scale     

《Applied Ocean Research》2019

The propulsive efficiency maximization of contra-rotating azimuth propulsor (CRAP) at model scale is investigated through searching the optimal matching rotational speeds of the forward propeller (FP) and rear propeller (RP) of CRAP based on the potential-based panel method. The hydrodynamic performance of CRAP with changing rotational speeds (FP and RP may have different rotational speeds) are calculated. When the inflow velocity is certain, the cubic spline interpolation method is used to get the equal thrust points at which CRAP has the same thrust with the corresponding conventional propeller (CP). Then, the delivered powers at these equal thrust points are further obtained through cubic spline interpolation method. The rotational speeds of FP and RP at the equal thrust point corresponding to the minimal delivered power are the optimal matching rotational speeds of CRAP. The optimal matching calculations are carried out at different inflow velocities. The results of the optimal matching investigation show that CRAP has the lowest delivered powers when FP and RP have the optimal matching rotational speeds and that the energy saving level decreases with the increase of inflow velocity. The optimal matching rotational speed ratio decreases with the increase of inflow velocity. In general, the delivered powers of CRAP having optimal matching rotational speeds at different inflow velocities are obviously smaller than those of CP.  相似文献