一种基于单位超球面平均的盲反卷积方法

在机器学习理论中,为消除随机影响,对样本进行平均是一种广为使用的处理手段.为此,在具有相同物理激发过程的系统中,利用黎曼梯度的概念,构造了单位超球面上的平均算子.以地震数据盲反卷积为例,结合改进型的带状独立分量分析,提出了基于单位超球面平均的盲反卷积方法.仿真实验表明了所提出方法的有效性和优越性.     

基于NBICA的盲反卷积方法

在线性系统假设下,根据地震记录估计地震子波和反射系数序列是一个典型的盲反卷积过程。针对带状独立分量分析反卷积方法对噪声敏感的缺点,提出一种的基于高斯矩的噪声带状独立分量分析反卷积方法,并利用邻近道间的相关信息实施子波提取。实验结果表明,对于带噪地震数据的盲反卷积,该算法性能更优。     

一种用于地震断层图像识别的SPD-UNet模型

断层是控制油气田形成和分布的主要因素,断层检测和识别对于油气勘探具有重要作用。基于Attention-UNet神经网络模型,构建一种面向地震断层图像识别的SPD-UNet模型。引入空洞卷积,在保证卷积核感受野大小且不损失原始图像分辨率的情况下,增强SPD-UNet模型的断层图像特征提取能力。将金字塔结构的空洞卷积组合成SPD模块,解决空洞卷积的局部信息丢失问题,提高断层信息关联性及图像识别精度。实验结果表明,SPD-UNet模型对于地震断层图像的识别精度优于SegNet与ResUNet模型,并且识别结果与实际标注的地震断层形状及位置更接近。     

离散卷积反演的W变换方法

离用卷积反演在数字信号处理中占重要地位，本文提出了离散循环与斜循环卷积反的Ｗ变换方法，结果表明，本文方法所需运算量比传统的快速傅里叶变换方法（ＦＦＴ）减少一半以上，同时证明了本文方法是弱稳定的。     

白噪声Wiener反卷积滤波器

应用现代时间序列分析方法,基于ARMA新息模型提出了白噪声Wiener反卷积滤波器。该滤波器可统一处理滤波、平滑和预报问题,可用ARMA递推滤波器实现,适用于石油地震勘探数据处理。同多项式方法和Kalman 滤波方法相比,避免了求解Diophantine方程和Riccati方程,减少了计算负担。Bernoulli-Gaussian白噪声反卷积的仿真例子说明了其有效性。     

微震震源定位算法优化研究及应用

微地震监测过程中,如何精准、实时地反演出微地震源的位置对生产应用起到了重要作用.国内外学者通过对微地震震源反演原理的研究提出很多反演方法,如纵横波时差法、模拟退火法、多个参数联合反演等,其中震源扫描叠加算法(source-scanning algorithm,SSA)由于其客观性和易用性得到广泛应用.通过研究微地震定位...     

计算机仿真技术在地震及结构振动分析中的应用

计算机仿真技术是通过对模型的计算机分析来模拟实际系统状态的变化过程，这一技术用于地震工程及结构振动分析有特殊的作用。然而由于土建工程的可统计性差，影响因素多，不信息多等等特殊原因，使得土建工程中应用计算机比其他地领域要晚些，本文针对目前由物理模型、数值方法和计算机可视化、多媒体，虚拟现实技术相结合而局长 起来的仿真作了的研究，并将其引入地震工程及结构振分析中，为结构地震动力分析了一条新的途径。     

数字反卷积中的时域正则化

本文讨论数字反卷积中的时域正则化问题。主要介绍使用复合滤波器减小噪声影响的方法,并给出一组实测数据的反卷积结果。     

适应扰动的无人直升机姿态跟踪控制

无人直升机在实际飞行过程中,会受到阵风等外界因素的干扰,并且模型不确定性也会对控制效果带来不利影响.为应对这些挑战,本文设计了一种基于扩张状态观测器的自抗扰反步控制器.首先,建立了无人直升机姿态动力学模型.随后,引入扩张状态观测器,用以实时观测由外界扰动和模型不确定性组成的总和扰动.观测得到的总和扰动估计值与基于Lyapunov函数的反步法控制器控制算法相结合,用以消除总和扰动的影响,使得无人直升机在各种飞行条件下均能对运动指令进行快速和准确的跟踪.最后,仿真研究和飞行实验验证了该控制律的有效性.与同等条件下的PID控制器相比,该控制律表现出更优的飞行性能.     

一种新的非白化滤波的自适应反卷积

提出了一种新的自适应预测反卷积的方法:基于知识的自适应滤波(NBA,knowledge based Adaptive filter).采用该法可以将先验的波形知识与自适应滤波技术相结合,实现缓变系统的自适应反卷积.与普通自适应预测反卷积相比,NBA方法由于加入了先验的波形知识,从而在输出波形失真误差上及自适应学习速度上均有很大的改善,特别是该方法不再限于仅可对白噪与线性系统的卷积才可进行反卷积的理论限制,提出了一种非白化滤波的自适应反卷积技术.本文从原理上及计算机仿真结果上证实了NBA法的有效性.     

Speech deconvolution as an inverse problem

In this paper, the problem of speech deconvolution is solved. This problem is encountered in limited-bandwidth speech communication systems such as telephone systems. Three solutions are presented for this problem. In the first solution, a Linear Minimum Mean Square Error (LMMSE) approach is used. The necessary assumptions required to reduce the computational complexity of the LMMSE solution are presented. In the second solution, an inverse filter deconvolution approach is presented. Finally, the regularization theory is used to solve this problem. The common thread between all these solutions is that they treat the speech deconvolution problem as an inverse problem considering the speech degradation model. Simulation results reveal the superiority of these solutions for solving the speech deconvolution problem.     

A Polynomial Approach to Bias Aware Fixed-Lag Smoothing Problem

In the present technical note, a solution to the problem of fixed-lag smoothing of SISO systems in presence of a dynamical bias is presented in a polynomial framework. The bias aware smoothing problem is solved in three steps, namely, the design of the general structure of the smoother, the estimation of the dynamical bias by means of a deconvolution technique and, then, the combination of the previous results to obtain the bias aware fixed-lag smoother. Applied to an example, this approach shows its efficiency.      

k-dimensional error-free deconvolution using the fermat number transform

The paper presents the generalization of the one-dimensional deconvolution algorithm using the Fermat number transform for the k-dimensional deconvolution. The problems of how to express a k-dimensional convolution system in the form of special matrix equation, how to calculate the precise value of the matrix determinant and how to remove rounding-off errors in the process of deconvolution, are solved in the paper. The results are used in the algorithm derivation.     

使用面积积分模型探究锥束CT功能成像的方法

为解决锥形束电子计算机断层扫描（CBCT）在功能成像中不能直接扫描获取体素时间-密度曲线（TDC）的问题,提出锥束CT功能成像的数学模型,得到灌注参数。首先建立模拟投影数据的面积积分模型,利用新西兰大白兔动态对比增强断层（DCE-CT）图像仿真模拟出锥束CT投影数据;利用模拟的投影数据,建立功能模型,使用最优化数值技术求解模型参数,获得各体素的近似TDC,并与实际测量的TDC对比验证模型的正确性;使用去卷积模型,利用最优化参数技术求解灌注参数。使用面积积分模型的模拟TDC与实际值的相似度达到了82.91%,使用此TDC可计算灌注参数并进行伪彩成像。利用CBCT投影数据和功能模型可得到体素近似TDC及组织的灌注参数,实现CBCT功能成像的目的。     

Elastic bar transfer functions determination using one-point strain measurements

Measurements of impulsive forces and pressures by means of the elastic bar require that the effect of waves’ dispersion in the bar on the sensor's output signal be corrected. The correction problem can be solved using deconvolution techniques. For this purpose it is necessary to determine the elastic bar's transfer functions. In this paper, an experimental method of determining the elastic bar's transfer functions in form of formulas is described, which can be used to reconstruct the input waveform. The method is based on: one-point measurement of the elastic strain waves propagating inside the bar, the spectral analysis of these waves and making use of the general solution of the equation of movement of the bar in the frequency domain. The determined transfer functions of the bar are used for impulsive strain waveform reconstruction by means of deconvolution in the frequency domain, and for the validity check of the reconstruction. The application of this method to the reconstruction of impulsive force waveforms generated by the mechanical impact of bodies is presented.     

A Novel Hybrid Model Framework to Blind Color Image Deconvolution

This paper presents a new hybrid model framework to address blind color image deconvolution. Blind color image deconvolution is a challenging problem due to the limited information on the blurring function. Conventional methods based on the single-input single-output (SISO) model experience suboptimal results as each color channel is processed independently. On the other hand, there are limitations on the practicality of using a multiinput multioutput (MIMO) model in solving this problem as the color channels are usually highly correlated. In view of these constraints, this paper proposes a novel framework to solve blind color image deconvolution by first decomposing the color channels into wavelet subbands, and performing image deconvolution using a hybrid of SISO and single-input multioutput models. The proposed method utilizes the correlation information among different color channels to alleviate the constraints imposed by the MIMO systems. Experimental results show that the method is able to achieve satisfactory restored images under different noise and blurring environments.     

Deblurring by Matching

Restoration of the photographs damaged by the camera shake is a challenging task that manifested increasing attention in the recent period. Despite of the important progress of the blind deconvolution techniques, due to the ill-posed nature of the problem, the finest details of the kernel blur cannot be recovered entirely. Moreover, the additional constraints and prior assumptions make these approaches to be relative limited.
In this paper we introduce a novel technique that removes the undesired blur artifacts from photographs taken by hand-held digital cameras. Our approach is based on the observation that in general several consecutive photographs taken by the users share image regions that project the same scene content. Therefore, we took advantage of additional sharp photographs of the same scene. Based on several invariant local feature points, filtered from the given blurred/non-blurred images, our approach matches the keypoints and estimates the blur kernel using additional statistical constraints.
We also present a simple deconvolution technique that preserves edges while minimizing the ringing artifacts in the restored latent image. The experimental results prove that our technique is able to infer accurately the blur kernel while reducing significantly the artifacts of the spoilt images.     

移动IP路由方案研究

移动IP技术使移动节点可以用一个永久的IP地址连接到任何链路上,但是也带来了三角路由的问题.路由问题一直是研究的热点,但是目前仍未能很好地解决.介绍了移动IP的工作原理、"三角路由"的成因,对移动IP技术中的几种路由方案进行了分析研究,提出了一种改进方案,并引入了安全机制.该方案较好地解决了三角路由和移动节点频繁切换所带来的延时问题.     

电磁层析成像技术的研究

本文从电磁层析成像（ＥＭＴ）技术的原理入手,对成像技术中的正问题给出了解析解,并利用Ｈｏｐｆｉｅｌｄ网络模型对其逆问题进行了定性的求解。在一定程度上为研究电磁层成像技术提供了一条可行的途径。     

Optimal Solution of Fuzzy Transportation Problem Using Octagonal Fuzzy Numbers

In this paper a fuzzy transportation problem under a fuzzy environment is solved using octagonal fuzzy numbers. The transportation problem is significant and has been widely studied in the field of applied mathematics to solve a system of linear equations in many applications in science. Systems of concurrent linear equations play a vital major role in operational research. The main perspective of this research paper is to find out the minimum amount of transportation cost of some supplies through a capacitated network formerly the availability and the demand notes are octagonal fuzzy numbers. Octagonal fuzzy numbers are used and showed a membership function. To illustrate this method, a fuzzy transportation problem is solved by using octagonal fuzzy numbers using the ranking technique. It is shown that it is the best optimal solution and it is demonstrated with a numerical example.