钛精矿回转窑直接还原过程结圈可能性的探讨

通过煤种，入窑球冷态强度和还原过程强度，以及钛精矿与煤灰混合物的软化温度等分析探讨了钛精矿预热球团回转窑直接还原产生结圈的可能性，获得了可以避免结圈的结论。     

煤矿井下便携式电子设备电源设计要点

针对便携式电子设备的电源性能影响设备稳定运行的问题,探讨了便携式电子设备电源设计要点:介绍了电池类型的选择,指出选择锂电池作为后备电池较为理想;分析了电源安全栅的保护方式,指出先限流后截止的安全栅保护方式可有效提高电源的抗干扰能力;针对电池Boost升压电路中出现的振铃问题,给出了优化Boost变换器关键环路的解决方法,有效减小了电源纹波。     

Contourlet变换低通滤波器对图像融合算法影响的讨论

根据Contourlet变换多尺度、多方向的特性以及自然图像的频谱特点, 分析了Contourlet变换低通滤波器对图像融合算法性能和融合结果中伪轮廓的影响, 讨论了低通滤波器与分解层数选取之间的关系. 理论与实验证明, 使用带宽较窄的低通滤波器能够得到较好的融合结果, 当低通滤波器系数均为正数时融合图像的伪轮廓显著减少. 本文比较了使用不同低通滤波器和不同融合准则时得到的融合结果, 实验结果证明, 使用合适的低通滤波器, 可以在选用较简单的融合准则和分解较少层数的情况下, 得到很好的融合结果, 大大减小了融合算法的复杂度.     

某型船尾部异常噪声研究

试航中发现某型油船主机在450～600r/min时,在螺旋桨的正上方能明显听到异常噪声.通过定性分析排除了螺旋桨上有缠绕物、轴系的配合问题,定量分析排除了螺旋桨出现"谐鸣"的可能性,实船测试分析结果表明产生噪声的原因是由于螺旋桨出现了梢涡空泡现象.研究为船舶的同类现象提供参考.     

基于光纹特征的激光主动照明图像去模糊

受光学系统离焦、大气扰动、平台振动的影响,激光主动照明系统捕获的图像容易被模糊,而传统的去模糊方法难以取得良好的复原效果,故本文提出基于光纹特征的盲解卷积复原方法来实现图像去模糊。首先将模糊图像降采样,建立尺度金字塔,在尺度空间查找光纹特征图像块。随后基于激光主动照明图像饱和像素较多的特点,提出新的图像退化模型。最后针对模糊核估计、光纹参数更新、清晰图像复原3个步骤,提出适用的能量函数,迭代复原出无噪清晰图像。搭建了主动照明系统,在捕获的激光主动照明图像上进行了实验,并与现有方法进行了对比。结果表明:本文方法不仅能够复原出清晰图像,而且能有效抑制振铃效应,其客观评价指标峰值信噪比(PSNR)优于已有的其他算法。     

基于边缘分离的去振铃复原

针对模糊图像复原后常常存在的振铃现象,提出了一种基于边缘分离的去振铃复原方法。该方法首先使用基于图像质量评价的降晰函数辨识方法估计模糊图像的降晰函数尺寸,提取模糊图像中的强边缘并平滑边缘区域得到去边缘模糊图像。然后,利用估计降晰函数对去边缘模糊图像进行迭代盲复原。最后,提取边缘增强后加入到复原的去边缘图像中得到完整的复原图像,并对复原图像进行增强。复原过程中为了抑制噪声放大使用了Wiener和离散小波变换(DWT)联合去噪算法对图像的低频区域进行去噪。实验结果表明:与传统的迭代复原算法相比,本算法复原图像的振铃测度降低了34%以上,比基于Fuzzy滤波器的去振铃算法低12.5%以上;同时,本算法复原的图像质量也得到了明显提升。     

混合递归超分辨率图像重构ZHANGDi,PENGHong.Hybridrecursivesuper-

超分辨率图像重构是将多帧低分辨率图像重构成一幅高分辨率图像的过程。一般的超分辨率图像重构算法在小放大倍数时效果比较好,但当放大倍数上升时,存在两个问题:一个是计算复杂性的急剧上升,另一个是边缘振荡效应的加剧导致成像质量迅速恶化。提出了一个能同时解决这两个问题的基于POCS的混合递归重构算法,实验结果表明,该算法能够在提高重构图像质量的同时,较大地提高重构速度。     

RCC电路原理分析与设计

自激变换器(RCC)的优点非常突出,低成本、可靠性高,广泛应用于工业和民用领域,本文详细介绍了自激变换器电路的工作原理和设计步骤。     

Influence of digital audio filters on image reconstruction in MRI

This paper deals with the influence of the transient response and group delay of digital filters on the MRI signal and its aspects in image reconstruction. The consequence of digital filtration on the acquired signal will be shown in the time domain (κ-space) for three basic imaging methods-echo scan, radial scan and spiral scan. The influence of the group delay and transient response of filters will be explained and a method will be proposed which compensates both these phenomena while retaining all the advantages of digital filtration. The proposed method is based on applying the principle of signal superposition and on using the consequences of the sampling principle. The method works in the time domain. It is very simple and rapid and does not depend on the properties of the acquired signal or reconstruction algorithm. It will be shown and explained in which cases the transient response can be neglected and in which it has to be compensated. In the end, the results of the proposed methods will be shown for mentioned cases on a simulated signal in the image domain. © 1998 Elsevier Science B.V. All rights reserved.     

Design of a new restoration algorithm based on the constrained mean-square-error criterion

In this paper the joint optimization of different criteria is addressed, as a powerful means of incorporatinga priori information in linear image-restoration algorithms. Theconstrained mean-square-error (CMSE) approach is introduced, which enables the incorporation of both spatial and spectral information regarding the peculiarities of the problem. Depending on the nature of the spatial information, this approach can be interpreted as either a regularized or an adaptive scheme. As a regularized scheme, it offers an alternative to conventional approaches, in which the ringing artifacts are efficiently suppressed by means of the regularizing operator. As an adaptive scheme, the CMSE approach offers the flexibility of applying either linear Wiener filtering or inverse filtering, depending on the local signal activity. Optimal techniques for the selection of the regularization parameter in both nonadaptive and adaptive cases are introduced. The capabilities of the CMSE approach as a regularized scheme and an adaptive scheme, are demonstrated through restoration examples.