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PHASE UNWRAPPING WITH HYBRID PARTICLE SWARM OPTIMIZATION ALGORITHM
基于混合微粒群算法的相位解缠

Fan Hongdong,Deng Kazhong,Xue Jiqun,Zhu Chuanguang,
范洪冬
,邓喀中,薛继群,祝传广

大地测量与地球动力学 , 2010,
Abstract: 针对Goldstein枝切线及蚁群解缠方法存在的问题,提出一种基于混合微粒群算法的相位解缠方法。该算法首先对奇异点进行预处理,将其分为偶极点、边界点和内部点;然后,利用相干图对内部点分区,并采用混合微粒群算法生成各自区域内的最短路径;最后,将这些最短路径分割成电荷平衡的小段枝切线,并对边界点和剩余未连接的奇异点按照窗口扩展法生成枝切线。实验表明,该算法比传统枝切线解缠方法更加有效。
一种新的INSAR相位解缠方法  [PDF]
孙学宏,于向明,刘丽萍,曾志民,张成
- , 2016, DOI: 10.13190/j.jbupt.2016.02.002
Abstract: 摘要 针对Goldstein枝切线法存在的问题,根据残差点的分布特点,提出了一种新的干涉合成孔径雷达相位解缠方法.该方法首先对邻近偶极子对进行预处理,生成独立且长度很短的枝切线,使用自适应遗传模拟退火算法计算剩余正负残差点的优化组合,不仅在短时间内设置出总体长度较短的枝切线,且有效地避免了大面积"孤岛"出现.实验结果表明,相比于几种典型的相位解缠算法,该方法在时间和精度上具有优越性.
Due to disadvantages of Goldstein's branch cut algorithm, a new phase unwrapping method for interferometric synthetic aperture radar (INSAR) was proposed according to distribution characteristics of residue. Firstly, the neighbor dipoles preprocessing algorithm was performed to establish independent and short branch cuts. Secondly, the adaptive genetic simulated annealing algorithm was performed to calculate optimized combination of remaining residues. Ultimately, the branch cuts with short length was generated in a short time, and large "isolated island" phenomenon was avoided. Experiment shows that the proposed method has advantages in precision and operation time compared with some typical phase unwrapping algorithm.
CONVERGENCE PROPERTIES OF A HYBRID CONJUGATE GRADIENT METHODS WITH GOLDSTEIN LINE SEARCH
Goldstein线搜索下混合共轭梯度法的全局收敛性

Jiao Baocong,Chen Lanping,Pan Cuiying,
焦宝聪
,陈兰平,潘翠英

计算数学 , 2007,
Abstract: In this paper, we propose a hybrid of conjugate gradient methods for unconstrained optimization based on Fletcher-Reeves Algorithm and Dai-Yuan Algorithm, which had taken the advantages of two Algorithms. The convergence of the new methods is proved with the Goldstein line search and without the descent condition . Numerical experiments show that the algorith is efficient.
Goldstein线搜索下混合共轭梯度法的全局收敛性  [PDF]
焦宝聪,陈兰平,潘翠英
计算数学 , 2007,
Abstract: 本文结合FR算法和DY算法,给出了一类新的杂交共轭梯度算法,并结合Goldstein线搜索,在较弱的条件下证明了算法的收敛性.数值实验表明了新算法的有效性.
基于改进人工势场法的多机动态改航路径规划  [PDF]
张兆宁,赵召娜
武汉理工大学学报 , 2015,
Abstract: ?危险天气会影响航班的正常飞行,因此需要研究危险天气影响下的航班改航路径规划的问题。改进了传统人工势场法中的斥力势函数,将航空器与其对应的目标点之间的距离以及航空器与障碍物的运动速度考虑在内,建立了改进人工势场法的多机动态改航路径规划模型。该模型解决了航空器因受力不为零而徘徊运动的现象,并且适应动态运行环境。算例验证了该模型的有效性和可行性。
优化的区域增长InSAR相位解缠算法  [PDF]
郭春生
中国图象图形学报 , 2006, DOI: 10.11834/jig.2006010230
Abstract: 在区域增长的干涉合成孔径雷达(InSAR)相位解缠算法中,种子的选择和种子相位值的确定是之一.本文研究了优化的区域增长2维相位解缠方法,包括合适的种子选取和种子相位值的优化处理,提出了将干涉相位图中相位跳变导致的边缘曲线作为种子,通过分析边缘曲线之间的相邻关系,基于遗传算法优化种子的相位值.仿真结果表明,该算法的计算量与干涉相位图的像素点数成近似线性关系,同时由于该算法属于局部算法,可以通过并行处理进一步提高计算效率.优化的区域增长2维相位解缠算法与其他2维相位解缠算法相比较,其解缠后的相位条纹与原始干涉相位图相位条纹的一致性非常好.该算法的处理结果与最小成本网络流相位解缠法相当,但其计算量却远远小于最小成本网络流相位解缠法的计算量.
热点应力法进行钢桥疲劳检算  [PDF]
王亚飞,徐海鹰
铁道工程学报 , 2012,
Abstract: ?研究目的:随着钢桥的重载化和整体化,桥梁钢结构中出现了较多无法明确其名义应力、现行规范也无对应细节的复杂构造。在实践中,对于该类细节多采用原形疲劳试验的方法进行验证。但疲劳试验的长周期和高费用,制约了该类细节的快速应用和推广。本文旨在用热点应力进行钢桥疲劳检算,实现在设计阶段尽可能准确地评估复杂细节的疲劳性能的目的。研究结论:本文分析计算了多种接头的热点应力集中系数,采用热点应力集中系数法推导了钢桥疲劳检算的热点应力shot~n曲线。bs5400规范多种构造细节的名义应力疲劳强度与导出的热点应力疲劳强度的对比表明,热点应力疲劳强度明显比名义应力法的离散性小,热点应力法适合桥梁工程应用。
SAR干涉图滤波与相位解缠算法比较研究  [PDF]
李陶,张诗玉,周春霞
大地测量与地球动力学 , 2007,
Abstract: ?在LP范数框架下,对经典的相位解缠算法的数学模型进行了研究,将解缠算法分为3类,并利用多种解缠方法对伊朗Bam地区的地形SAR干涉图进行了实验分析。结果表明:Goldstein滤波方法有效地减少了残点和枝切线的分布,提高了干涉图的视觉效果和信噪比。基于网络流的L1范数方法可以得到最优的全局解,但运算效率较低;L2范数方法也能得到较好的全局解,运算效率较高;L0范数方法不能得到很好的解缠结果,存在较多的断点和不确定性,但是运算速度极快。
Taylor-Goldstein equation and stability  [PDF]
Aravind Banerjee
Physics , 2005,
Abstract: Taylor-Goldstein equation (TGE) governs the stability of a shear-flow of an inviscid fluid of variable density. It is investigated here from a rigorous geometrical point of view using a canonical class of its transformations. Rayleigh's point of inflection criterion and Fjortoft's condition of instability of a homogenous shear-flow have been generalized here so that only the profile carrying the point of inflection is modified by the variation of density. This fulfils a persistent expectation in the literature. A pair of bounds exists such that in any unstable flow the flow-curvature (a function of flow-layers) exceeds the upper bound at some flow-layer and falls below the lower bound at a higher layer. This is the main result proved here. Bounds are obtained on the growth rate and the wave numbers of unstable modes, in fulfillment of longstanding predictions of Howard. A result of Drazin and Howard on the boundedness of the wave numbers is generalized to TGE. The results above hold if the local Richardson number does not exceed 1/4 anywhere in the flow, otherwise a weakening of the conditions necessary for instability is seen. Conditions for the propagation of neutrally stable waves and bounds on the phase speeds of destabilizing waves are obtained. It is also shown that the set of complex wave velocities of normal modes of an arbitrary flow is bounded. Fundamental solutions of TGE are obtained and their smoothness is examined. Finally sufficient conditions for instability are suggested.
COMPARISON AMONG DIFFERENT QUALITY MAPS USED FOR PHASE UNWRAPPING
不同质量图在相位解缠算法中的比较分析

肖枫,伍吉仓,刘朝功,张磊
大地测量与地球动力学 , 2010,
Abstract: 质量图指导算法是以相位质量图作为指导,从高质量的像素点开始解缠逐渐扩展到低质量的区域,亦可从多个区域同时解缠最后达到整体解缠,此类算法的关键就是选取合适的相位质量图对解缠过程进行指导。选取3种质量图对模拟数据及真实InSAR数据进行质量图指导法解缠分析,结果表明伪相干系数图具有较好的特性。
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