期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
基于相位信息的非均匀包络未知脉冲边沿估计方法
1
作者 孙敬雲 徐嘉岑 +1 位作者 范花玉 刘泉华 《信号处理》 CSCD 北大核心 2017年第12期1647-1651,共5页
对脉冲边沿的估计一直是雷达、电子侦察等领域的重要课题,其结果直接影响雷达特征的提取。本文针对接收脉冲未知且包络非均匀、有剧烈起伏的情况,提出了一种基于相位信息的未知脉冲边沿估计方法。该方法利用信号和噪声相位的统计特性不... 对脉冲边沿的估计一直是雷达、电子侦察等领域的重要课题,其结果直接影响雷达特征的提取。本文针对接收脉冲未知且包络非均匀、有剧烈起伏的情况,提出了一种基于相位信息的未知脉冲边沿估计方法。该方法利用信号和噪声相位的统计特性不同,通过计算接收信号的分段相位标准差将信号段和噪声段区分开来,从而得到脉冲边沿的粗估计;然后在粗估计范围内对信号段进行滑窗检测,进而得到脉冲边沿的精确估计。理论分析和仿真结果表明,当脉冲包络起伏剧烈时,该算法可以有效解决传统脉冲边沿估计方法存在的脉冲分裂问题,且具有运算量小,精度较高的特点。 展开更多
关键词 非均匀包络 脉冲边沿估计 相位标准差 门限检测 滑窗检测
下载PDF
Capacities and Failure Modes of Suction Bucket Foundation with Internal Bulkheads 被引量:4
2
作者 XIAO Zhong GE Borui WANG Yan 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第4期627-634,共8页
Suction bucket foundations can be divided into four compartments by cruciform internal bulkheads,thereby yielding better capacity in certain conditions than those without internal bulkheads.As yet,no systematic study ... Suction bucket foundations can be divided into four compartments by cruciform internal bulkheads,thereby yielding better capacity in certain conditions than those without internal bulkheads.As yet,no systematic study has been conducted regarding the effects of cruciform internal bulkheads on the capacities of suction bucket foundations.In this study,we established a large number of finite element models of suction bucket foundations with and without cruciform internal bulkheads and of solid embedded circular foundations.We found the uniaxial capacities and failure modes of suction bucket foundations with various depth ratios to remain basically unaffected by internal bulkheads in uniform clays.However,in inhomogeneous clay with high strength heterogeneity,we observed the uniaxial moment and horizontal capacities and corresponding failure modes of suction bucket foundations with a low depth ratio to be obviously affected by internal bulkheads.In this case,the uniaxial moment capacities,in particular,as well as the horizontal capacities of suction bucket foundations with cruciform internal bulkheads become obviously greater than those without internal bulkheads.Under combined loading,we found the failure envelopes of suction bucket foundations with and without cruciform internal bulkheads and of solid circular foundation to also be basically consistent in uniform clays.However,in inhomogeneous clay with high strength heterogeneity,cruciform internal bulkheads can obviously change the shapes of the failure envelopes of bucket foundations with a small depth ratio.We conclude that when the acting vertical load or foundation depth is relatively small,suction bucket foundations with cruciform internal bulkheads can be subjected to larger moment and horizontal loads in soft clays with high strength heterogeneity. 展开更多
关键词 capacity bucket foundation internal bulkheads undrained clay failure modes
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部