肇庆海事:敬业护航 惠企利民

正2017年,肇庆海事局以"三化"建设为引领,紧紧围绕广东海事局八项工作任务,着力抓好"两个安全"和"三大战役",扎实做好"六个推进",维护了辖区安全形势的持续稳定。全力以赴打好广东海事局"三大战役"2017年广东海事局全面打响"三大战役"("平安西江"建设、安全大巡察、防治船碰桥)。肇庆海事局严格按照广东海事局部署,全面推动"三大战役"的贯彻落实。一年来,肇庆海事局积极开展"平安西江"建设。8月8日"平安西江"启动仪式在肇庆顺利进行,西江沿江6地市政府、省相关政府职能部门     

基于引力搜索算法参数优化的改进PCNN遥感图像分割

为了提高遥感图像目标分割的精度,提出了一种基于引力搜索算法参数优化的改进脉冲耦合神经网络(pulse coupled neural network,PCNN)遥感图像分割算法.首先对经典PCNN模型进行改进,重新描述神经元之间的激励和抑制关系,改进连接输入项和动态阈值.然后利用新颖的PCNN模型对输入图像进行点火处理,并从其输出结果中提取图像熵和能量的比值作为引力搜索算法的适应度函数,且将熵的变化值作为引力搜索算法的收敛依据,利用引力搜索算法的全局搜索能力寻找PCNN模型中影响分割效果的关键参数的最优值.最终通过Matlab仿真,将该方法与OTSU方法、最大熵直方图分割算法和PCNN分割方法进行对比,结果证明文中方法具有较好的分割效果,更适用于遥感图像的分割.     

Numerical analysis of the soil compaction degree under multi-location tamping

Dynamic compaction (DC) is an efficient soil improvement technique. The previous numerical studies mainly focus on the soil response of single location tamping, but ignore the soil compaction degree under multilocation tamping. In this study, a numerical investigation of multi-location tamping in granular soils is carried out using three-dimensional (3D) finite element model (FEM). The behaviors of the granular soils are described by means of the viscoplastic cap model. The constitutive relationship of the soils is implemented into LS-DYNA and is integrated with 3D FEM for numerical investigation. Then utilizing the field data from the previous studies, we investigate the soil compaction degree at different stages by a case of two basic patterns, and discuss the cause of soil response. Lastly, we evaluate the effect of construction parameters on soil compaction. The simulation results show that the previous tamping affects the soil compaction degree beneath the adjacent tamping location, and the effect is greater near the side of previous location. Meanwhile, the soil compaction degree around the existing tamping crater weakens due to the adjacent tamping. Moreover, the rational selection of DC construction parameters can improve the soil compaction degree, and some hints on the effect of soil compaction are given.     

基于WinCE平台的船舶数据记录仪监控系统开发

以基于WinCE平台的嵌入式工控机与PC机组成的局域网为核心,以EVC/VC为工具,采用WinCE所支持的多线程操作、数据库、WinSock通信等技术,开发出了专门记录船舶航行过程中各设备工况的监控系统,它可对船舶各设备信息进行现场数据采集、存储、监控、加密与传输,为船舶事故调查与船舶设备故障诊断提供科学依据.经实际调试与运行,该系统运行稳定,性能可靠,实时性好,安全性高,在船舶行业具有很好的应用前景.     

企业竞争力评价的系统模型及方法

当前有关竞争力评价的研究由于缺乏企业竞争优势的系统观念，往往在评价过程中过于片面，对企业的战略实践缺乏有益的指导。本试图通过在对企业竞争力形成机制理解的基础上，建立一个企业竞争力评价模型，并系统地对企业的竞争力进行评估，为企业的竞争和战略的制定及实施提供有益的工具。     

The settlement characteristic of underground urban complex in Shanghai

The effects of excavation unloading, construction reloading and underground water on basal heave of excavation projects were presented and analyzed based on the measurement results of an underground urban complex which was located in Shanghai. The effects on water pressure and building settlements were analyzed as well. The numerical analyses by finite element method (FEM) were conducted. It showed that the soil under the excavation base continued to heave during the following certain construction stage. It also found that the bearing capacity of uplift piles which supported the buildings affected the structure quality significantly. The conclusions can be applied in future projects. Foundation item: the National Natural Science Foundation of China (No. 50679041)     

采用双DSP控制的并联型有源电力滤波器

为满足三相四线制电力用户在滤除谐波的同时进行无功功率补偿的需要,采用基于三相瞬时无功功率理论的ip-iq检测法,结合无差拍PWM控制方法,通过双DSP芯片控制的主功率电路实现谐波抑制和无功补偿的功能.首先对有源电力滤波器的基本工作原理作了描述,然后对检测和控制算法做了相应的推导论证,并用MATLAB-SIMULINK工具进行了仿真验证,最后在以TMS320LF2407A和TMS320VC33两块DSP芯片为核心控制部件的试验样机上进行了试验.仿真和实验结果表明,这种有源电力滤波器能够实时、动态地抑制谐波和补偿无功功率,因而可以在三相四线制电力系统中推广应用.     

集装箱船外飘砰击载荷的CFD数值分析

基于黏流CFD方法研究迎浪工况下波长和波高对KCS船运动和外飘砰击的影响,分析砰击压力的时空分布及其与船舶垂向运动的关系。基于开源造波工具waves2Foam建立三维数值水池,采用naoe-FOAM-SJTU求解器中的重叠网格技术求解船舶在波浪中的运动。计算结果表明,船舶运动幅值随波长和波高的增大而增大,波长船长比为1时外飘砰击压力最大,外飘砰击压力随波高增大呈线性增大规律。集装箱船应尽量避免在波长接近船长的海况下航行。这项研究可为波浪中的船舶砰击载荷预报提供参考。     

在服务构建新发展格局中加快推进珠江水运高质量发展

2020年是极不平凡的一年. 面对国际国内形势的深刻复杂变化,特别是突如其来的新冠肺炎疫情,我们在交通运输部党组的坚强领导下,与珠江水系各级交通运输管理部门和港航企业同舟共济,以一往无前的奋斗姿态、风雨无阻的精神状态,统筹做好疫情防控和珠江水运发展工作,在不平凡之年取得了不平凡的成就.     

舰载雷达多路径效应仿真研究

文章着重研究了海面反射产生的多路径效应对舰用电子支援措施(ESM)中雷达的影响,推导了多路径效应的信号模型,并在MATLAB中模拟ESM的密集电磁脉冲环境,分析了多路径效应的频域特性,建立了多路径效应的仿真模型.