排序方式: 共有45条查询结果,搜索用时 250 毫秒
1.
2.
3.
4.
The radiation directivity of a complicated conformal array of underwater acoustic transducers is presented based on the boundary "element method. It includes the element directivity of each transducer, the natural beam pattern and the controlled beam pattern of the transducer array. At first, the boundary element model of the conformal array is built up, and then the boundary condition is exerted on the model according to the design and environment in which the transducer array is used, and the radiation directivity of the conformal array is calculated. An experiment has been done to measure the directivity in an anechoic water tank. The calculated and the experimental results are compared and analyzed. They are consistent to each other. It is shown that the boundary element method together with the detailed calculations is successful to simulate and predict the radiation directivity of an underwater acoustic transducer array. 相似文献
5.
Two vertical-cavity surface-emitting lasers(VCSELs) are mutually coupled through a partially transparent mirror (PTM) placed in the pathway. The PTM plays the role of external mirror,which controls the feedback strength and coupling strength.We numerically simulate this system by establishing a visible SIMULINK model.The results demonstrate that the anticipation synchronization is achieved and it can tolerate some extent frequency detuning.Moreover,the system shows similar chaos-pass filtering effect on unidirectionally coupled system even both VCSELs are modulated.This system allows simultaneously bidirectional secure message transmission on public channels. 相似文献
6.
本文介绍利用电阻网格模拟轴对称场的原理和方法。并把模拟实验结果与数值计算结果对比,证明模拟实验的精确性比较好,克服了用电解槽法模拟所特有的误差。 相似文献
7.
POT模型中GPD估计方法选择及金融风险测度 总被引:3,自引:0,他引:3
极大似然、矩、概率加权矩估计是GPD参数估计的主要方法.用蒙特卡罗模拟技术产生大量GPD数据,用三种方法估计参数.通过BIAS和RMSE判断估计方法优劣,研究其随样本量和形状参数变化的差异,得到估计方法选择的标准. 相似文献
8.
软件可靠性模型的Bayes推断及Gibbs算法 总被引:4,自引:0,他引:4
作为重要的软件可靠性模型,JM模型的研究具有重要意义.论文研究了JM模型Bayes估计及其Gibbs算法.在先验分布确定的情况下,给出了Bayes估计的Gibbs算法,并证明了其收敛性.最后通过模拟分析发现:在1≥100,k〉600时,所得到的参数Bayes估计与初始值几乎无关.从而说明Gibbs算法的可行性. 相似文献
9.
10.
EFP模拟弹丸侵彻陶瓷复合靶的数值模拟研究 总被引:1,自引:1,他引:0
运用LS_DYNA程序中描述陶瓷本构关系的JHC模型和二维轴对称拉格朗日算法,对EFP模拟弹丸侵彻不同厚度99氧化铝陶瓷块/金属复合靶试验进行了数值模拟,获得了侵彻过程中陶瓷的损伤演化和分布以及在A3钢背板中的侵彻深度,与实验结果进行了比对,总的侵彻深度基本相符。数值模拟和试验所得残余侵彻深度与陶瓷厚度之间基本上都呈一种良好的线性关系,因此所得质量防护系数和差分防护系数都随着陶瓷厚度的增加而增加。通过分析侵彻过程中的陶瓷损伤与演化发现:陶瓷块尺寸过小时会由于稀疏波作用使陶瓷抗弹性能下降。 相似文献