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1.
富利叶交换滤波在地震勘探数字处理中的应用   总被引:1,自引:0,他引:1  
本文推出不倒地址的快变计算公式,提出编制节省计算时间程序的方法,在地震数字处 理中使用频域时变滤波方案实际计算时间与时域递归滤波相当。对二维滤波讨论了正负速度 区别解决了时域滤波产生坑席现象的问题,计算方法比时域滤波统一,简单,计算时间省。 提出的频域反滤波方案也比时域反滤波计算简单时间省。  相似文献   

2.
一种改进的中值滤波算法   总被引:2,自引:0,他引:2  
讨论了非线性滤波的特点,分析了中值滤波的属性,在阈值分解的基础上,提出一种非线性递归中值滤波的改进算法,对其在信号和图像处理中的应用进行了初步的探讨,给出了该方案的仿真结果,结果表明,改进后的中值滤波算法与传统的中值滤波算法相比,前者在去噪同时保护边缘信息方面大大优于后者。  相似文献   

3.
基于高斯滤波的稳健工程表面评定方法   总被引:6,自引:0,他引:6  
分析了高斯滤波在实际工程表面评定中存在的不足,引入稳健估计理论,提出了一种新的基于高斯滤波的稳健算法,消除了异常值对高斯滤波 效率的影响,提高了高斯滤波的稳健性,实例分析结果表明,该方法能中靠地获得了评定基准,实现表面信息的无失真提取和分析,较之传统高斯滤波,更便于工程表面评定的实际应用。  相似文献   

4.
讨论了非线性滤波的特点,分析了中值滤波的属性,在阈值分解的基础上,提出了一种非线性递归中值滤波的改进算法.对其在信号和图像处理中的应用进行了初步的探讨,给出了该方案的仿真结果,结果表明,改进后的中值滤波算法与传统的中值滤波算法相比,前者在去噪同时保护边缘信息方面大大优于后者.  相似文献   

5.
粒子滤波器作为常用的非高斯非线性的滤波方法,已成功地应用于各种工程领域。然而传统的重采样方法导致了粒子贫化的问题,严重降低了滤波估计的精度与鲁棒性。文中提出一种结合跟踪失败检测与改进差分优化融合的自复位粒子滤波方法。首先通过跟踪失败识别方法对滤波估计值进行初步检验,在正常跟踪时不启用优化策略,算法性能与标准粒子滤波无异;在跟踪失败时,通过差分算法对粒子集进行复位,复位过程中设置了粒子置信区间的上下界以防粒子过度集中,并结合检验指示值规避对粒子的多次优化,以缩短算法的估计时间。仿真结果表明,文中算法通过动态调节方式继承了标准粒子滤波和差分进化粒子滤波的优点,有效提高了滤波估计的鲁棒性与估计精度,可在滤波成功时避免启用优化策略以降低算法的整体时间复杂度,并在滤波失败时启用差分优化策略进行自我复位以提高算法估计精度;且在相同定位精度下,其所需粒子数较标准粒子滤波更少,整体时耗较差分进化粒子滤波更低,在建模不确定时也可表现出良好的效果。  相似文献   

6.
对伪彩色中的色块图像边缘平滑处理,经过比较和实验不同的滤波方法,介绍了中值滤波有着其它滤波器所没有的良好特性。对中值滤波的窗口选择进行了详细地分析和讨论,并提出了中值滤波实施中的改进方法。  相似文献   

7.
本文介绍图像信号的加权中值滤波方法,探讨了加权中值滤波的分级加权优化与算法实现问题,给出一种新的分层加权结构,使之同时具有理想的噪声滤波和边缘保持效果。在实际图像滤波中得到了满意的验证  相似文献   

8.
用傅里叶变换轮廓术测量复杂物体形状时,频谱能量分布弥散,出现频率混叠现象,滤波时难以确定截止频率。选用了3种频域滤波窗以及小波滤波4种滤波方法对傅里叶变换轮廓术中的变形光栅图进行处理,计算机模拟并比较了在有噪声和无噪声的情况下不同滤波方法的误差分布。数据分析表明,选用合适的小波基对信号进行滤波处理比其余3种滤波器的测量精度要高。  相似文献   

9.
无电容R有源滤波电路   总被引:2,自引:0,他引:2  
利用实际集成运算放大器的频率特性,给出了仅由电阻R和运算放大器组成的无电容R有源滤波电路及其理论分析,并就R有源滤波电路参数对滤波特性和电路工作的稳定性影响作了详细讨论,给出了R有源滤波电路参数的取值条件。  相似文献   

10.
微光图像中值滤波与众值滤波理论与实验研究   总被引:1,自引:0,他引:1  
中值滤波法是图像平滑技术中常用的一种方法。但中值滤波法处理微光图像时有一定的局限性。该文对此做了进一步的实验与讨论,与众值滤波法进行了比较性研究。众值滤波法是对滤波窗口内所有像素点的灰度值作数学统计,并取出现几率最大的像素灰度值为为滤波结果,累此处理过的图像更接近真实。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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