一种基于非线性扩散方程的SAR图像相干斑抑制方法

研究合成孔径雷达(Synthetic aperture radar,SAR)图像的相干斑抑制问题.传统的相干斑抑制方法通常会导致图像中边缘和目标的模糊.针对该问题,分析了基于非线性扩散方程的相干斑抑制方法,该方法的关键在于扩散系数的构造.通过分析SAR图像的先验信息和SAR图像不同特征区域的不同处理要求,提出了一种新的更适合SAR图像相干斑抑制的扩散系数构造方法.实验结果表明,新方法相对现有方法具有更好的相干斑抑制能力和目标边缘特征增强能力,等效视数和边缘清晰度均提高了3倍左右.     

一种新的混沌方程及其超混沌网络模型

考虑器件实现方面的简单性,提出一种新的混沌方程模型,并通过单向耦合法构成超混沌网络。通过微机模拟表明网络具有丰富的混沌、超混沌现象。进而在单向耦合法基础上,提出参数耦合法,利用此方法,构造成的二维混沌网络具有超混沌动力学特性。网络具有高效、灵活、易于器件实现的特点。这种新的混沌方程及超混沌网络模型可望在提高激光器的输出功率、保密通信等领域获得广泛应用     

A new approach to analytically solving the two-dimensional Poisson's equation and its application in short-channel MOSFET modeling

An analytical solution for the potential distribution of the two-dimensional Poisson's equation with the Dirichlet boundary conditions has been obtained for the MOSFET device by using Green's function method and a new transformation technique, in which the effects of source and drain junction curvature and depth are properly considered. Based on the calculated potential distribution, the subthreshold current considering the drain-induced barrier lowering effects has been computed by a simple current equation that considers only the diffusion component with an effective length determined by the potential distribution at the SiO2-Si interface. From the calculated subthreshold current, the threshold voltage of the MOSFET's is determined. It has been verified that the dependences of the calculated threshold voltage and subthreshold current on device channel length, drain, and substrate biases are in good agreement with those computed by whole two-dimensional numerical analysis and experimental data.     

Adaptive error diffusion and its application in multiresolutionrendering

Error diffusion is a procedure for generating high quality bilevel images from continuous-tone images so that both the continuous and halftone images appear similar when observed from a distance. It is well known that certain objectionable patterning artifacts can occur in error-diffused images. Here, we consider a method for adjusting the error-diffusion filter concurrently with the error-diffusion process so that an error criterion is minimized. The minimization is performed using the least mean squares (LMS) algorithm in adaptive signal processing. Using both raster and serpentine scanning, we show that such an algorithm produces better halftone image quality compared to traditional error diffusion with a fixed filter. Based on the adaptive error-diffusion algorithm, we propose a method for constructing a halftone image that can be rendered at multiple resolutions. Specifically, the method generates a halftone from a continuous tone image such that if the halftone is down-sampled, a binary image would result that is also a high quality rendition of the continuous-tone image at a reduced resolution. Such a halftone image is suitable for progressive transmission, and for cases where rendition at several resolutions is required. Cases for noninteger scaling factors are also considered.     

A new design algorithm for two-band orthonormal rational filterbanks and orthonormal rational wavelets

We present a new algorithm for the design of orthonormal two-band rational filter banks. Owing to the connection between iterated rational filter banks and rational wavelets, this is also a design algorithm for orthonormal rational wavelets. It is basically a simple iterative procedure, which explains its exponential convergence and adaptability under various linear constraints (e,g., regularity). Although the filters obtained from this algorithm are suboptimally designed, they show excellent frequency selectivity. After an in-depth account of the algorithm, we discuss the properties of the rational wavelets generated by some designed filters. In particular, we stress the possibility to design “almost” shift error-free wavelets, which allows the implementation of a rational wavelet transform     

改进的迭代CKF及其在GNSS/INS紧组合中的应用

为改善GNSS/INS紧组合中非线性滤波器的稳定性和精度,基于Backtracking线搜索(BLS)方法提出一种新型的迭代容积卡尔曼滤波方法(BLS-ICKF)。首先建立Sigma点滤波方法的迭代框架,采用阻尼Newton迭代改善状态初始误差较大时的滤波更新精度,同时,为提高组合系统状态预测过程的鲁棒性定义了一种简化的迭代更新结构。实验和仿真结果表明,BLS-ICKF牺牲较小的时间复杂度较CKF的航向角误差减少约59%。     

A modified nonlinear diffusion model and its application to image smoothing and edge detection

A modified version of the Cotte. Lions, Morel and Coll theory for image selective smoothing and edge detection is proposed. Comparing with their model, the most important advantage of this modification is that the convolution with Gaussian processes in the filtering process is replaced by solving an initial-boundary value problem for the heat equation, which simplifies the numerical scheme to some extent. Numerical experiments on natural images are presented for this model.     

A new twist on the Marcum Q-function and its application

A new form of the Marcum (1950) Q-function is presented that has both computational and analytical advantages. The new form is particularly useful in simplifying and rendering more accurate the analysis of the error probability performance of uncoded and coded partially coherent, differentially coherent, and noncoherent communication systems in the presence of fading. It also enables simple upper and lower bounds to be found analogous to the Chernoff bound on the Gaussian Q-function     

A new memristor emulator and its application in digital modulation

Since its inception many proposals and attempts have been reported on using the memristor in digital signal processing (DSP) circuits. Memristor-based DSP applications are mainly focusing on improving the performance of memories and in realizing synapses in neural networks. In most of the reported applications the verification of the proposed DSP circuits is made using mathematical-based memristor models. In this paper a new circuit for practical emulation of the memristor and its applications in memristor-based digital modulation is experimentally investigated.     

激光散射理论及其在计量测试中的应用

本文系统地介绍了一门新近发展起来的学科---光散射及其应用技术。文中概述了散射理论的发展历史,详细介绍了瑞利散射定律及米氏理论,分析了散射与粒度、表面轮廓形貌统计特性及晶体内部微缺陷之间的数学关系,给出了激光散射在粒度、表面粗糙度测试及微缺陷检测中的应用实例.     

一种新的扩散混合机制

本文针对扩散混合新机制扩压函数，提出了它的基本设计原则。引入了级连布尔函数的概念，给出并证明了它的一些性质，在此基础上提出了单比特扩压函数的一种构造方法，并给出了一个具体的具有良好密码学性能且结构简单易于软硬件实现的单比特扩压函数实例。     

一种新的仿射不变特征及其在平面曲线匹配中的应用

构造了一种新的仿射变换不变特征,提出了一种适合于仿射变换的曲线匹配算法。首先将整个轮廓区域进行仿射区域划分,得到一系列子区域质心点;然后将质心和子区域的质心点按规则构成三角形,计算三角形的面积比序列,并将其规范化,构造新的仿射不变特征。在该不变特征的基础上设计新的识别向量和差异度度量函数,通过计算待识别目标与模型曲线之...     

新型激光扫描仪RF620及其应用

RIFFEK公司的RF620系列二维激光位移传感器（二维轮廓扫描仪）问世以来,以其极高的性价比久负盛名。该激光轮廓扫描仪主要应用于物体轮廓、二维尺寸、二维位移的非接触测量与检验,以及目标物体的分拣。本文介绍了此系列扫描仪的原理、接口、配置及软件开发工具。     

一种新的莫尔图及其在全息标识中的应用

提出一种能放大任意图案和文字的莫尔新技术。该技术可用于作为防伪全息标识的隐型密码。这种密码的防伪质量高且具有强烈的艺术效果。对其原理进行理论分析并用实验验证了它的可行性。给出了这种莫尔图作为密码在全息标识中的制作方法     

A new hybrid forecasting algorithm and its application in economic analysis

There exists a great deal of periodic non-stationary processes in natural,social and eco- nomical phenomenon.It is very important to realize the dynamic analysis and real-time forecast within a period.In this letter,a wavelet-Kalman hybrid estimation and forecasting algorithm based on step-by-step filtering with the real-time and recursion property is put forward.It combines the advantages of Kalman filter and wavelet transform.Utilizing the information provided by multi- sensor effectively,this algorithm can realize not only real-time tracking and dynamic multi-step fore- casting within a period,but also the dynamic forecasting between periods,and it has a great value to the system decision-making.Simulation results show that this algorithm is valuable.     

一种新的压缩顶点传输线矩阵法及其应用

文中基于加权因子，中心差分及场技术，从Ｍａｘｗｅｌｌ方程出发导出了对称压缩顶点传输线矩阵法的一种新格式。针对这种新的传输线矩阵法，给了了其稳定性条件以及在导体表面，介质分界面上的连结条件。数值结果证明了我们所提新格式的正确性和有效笥。     

A new feature fusion method at decision level and its application

To solve the problem that using only one feature is poor for the terrestrial environment classification,a new feature fusion method at decision level is proposed in this paper.An eigenvector is obtained by using a Gaussian mixture model(GMM) firstly,and the probabilities of the eigenvector belonging to a certain class of the texture and color are computed.Then the probabilities are multiplied by different weights according to the contribution,and summed to get the maximal likelihood probability to achieve f...