Dual-tree complex wavelet image denoising based on parental and neighboring coefficients

考虑二维双树复数小波变换(dTCWT)具有良好的平移不变性和方向选择性,基于当前系数与父系数及邻域系数间的关系,构造了dTCWT图像去噪阈值计算公式,提出了一种去噪方法,PndTCWT。该方法在对图像进行二维dTCWT变换后,利用阈值公式,根据当前系数和父系数及相邻系数计算收缩阈值,对当前系数进行去噪处理。最后,经过二维dTCWT反变换,得到去噪结果。实验结果表明,PndTCWT的噪声抑制效果明显优于各种基于dWT的去噪方法和其他dTCWT去噪方法。与基于父系数的dTCWT去噪方法相比,PndTCW的峰值信噪比(PSnr)平均提高了0.5 db左右。从视觉效果来看,PndTCW能在去噪的同时较好地保留图像细节,物体轮廓显得比较平滑,不存在传统dWT算法中的混淆现象。By considering the advantages of the 2D Dual Tree Complex Wavelet Transfer(DTCWT) in shift invariance and directionality,a threshold denoising formula based on parental and neighboring coefficients is constituted and a novel Parental and Neighboring DTCWT(PNDTCWT) image denoising method is presented.By proposed method,the shrinkage threshold of each coefficient is calculated to use in denoising for the current coefficient.After 2D DTCWT transfer to an original image, the final image is obtained by the inverse DTCWT of these denoised coefficients.Experimental results show that the denoising performance of the PNDTCWT is better than those of other denoising methods based on DWT or other DTCWT methods,and its Peak Signal Noise Ratios(PSNRs) have improves by 0.5 dB averagely as compared with that of parental coefficients based DTCWT denoising method.In terms of visual quality,PNDTCWT can get the images with more details,smooth profiles and without confusion effect.航空科学基金资助项目(No.05F07001);国家自然科学基金资助项目(No.60472081

神经导航在颅内胶质瘤显微手术的应用

目的　评价神经导航在颅内胶质瘤显微手术的应用价值。方法　应用神经导航系统进行颅内胶质瘤显微手术 30例。结果　用神经导航系统进行胶质瘤及其周围解剖结构定位准确 ,平均注册误差 (2 .5± 0 .4 )mm。术后近期复查CT或MR证实胶质瘤全切率 83.3% ,手术时间和住院日较常规开颅手术缩短。结论　 (1)神经导航定位精确 ,有助于手术计划的精确实施。 (2 )实时导航颅内胶质瘤显微手术 ,有助于达到微侵袭效果和提高胶质瘤全切除率。 (3)摸索一套减少靶点漂移的经验

稀薄大气密度涨落对高空超高速飞行器气动性能的影响

地球周围的大气环境特性,随高度的上升,显著变化。对于本文关心的高度100km附近高超声速飞行器气动特性而言,稀薄大气密度涨落影响是一个重要的问题。按照大气层划分,高度100 km属于热层。热层的下界高度约86 km,上界高度与太阳活动有关,在太阳宁静期约为200 km,太阳活动期约500 km。热层下接中间层(高度50～86 km),上连电离层(高度80～1000 km),大气研究已知,中间层主要受重力波和湍流影响,电离层主要受太阳活动和地磁效应影响。高度100 km附近空域,处在热层下界,重力波、湍流、太阳活动和地磁效应等均有影响,理论上需要Navier-Stokes方程和Maxwell方程..

Effects of La~(3+) on H~+ Transmembrane Gradient and Membrane Potential in Rice Seedling Roots

The effects of LaCl 3 on membrane potential and transmembrane proton gradient for rice ( Oryza sativa ) seedling roots were studied. Highly purified plasma membranes were isolated by aqueous two phase partitioning method. Both the gradient of transmembrane proton and membrane potential were stimulated by certain low concentration of LaCl 3 and depressed by high concentration of LaCl 3. The optimal concentration of La 3+ was around 40～60 μmol·L -1 for transmembrane proton gradient and membran...国家自然科学基金 ( 39970 438;39870 630 )资助项目 ;; 福建省自然科学基金 (C970 0 2 )资助项

Numerical Study on Tides in the Taiwan Strait and its Adjacent Areas

建立二维潮波模式,模拟了台湾海峡及其邻近海域(18~30°n,110~130°E)八个主要分潮(M2、S2、k1、O1、P1、Q1、k2、n2),并利用中国大陆及环台湾岛20多个潮位站的实测资料进行验证,计算结果与实测值吻合良好。此外,给出了八个主要分潮的同潮图,并逐个讨论了潮汐特征。结果显示:(1)台湾海峡中的潮波运动是北部蜕化了的旋转潮波系统和南部的前进潮波系统共同作用的结果。(2)半日分潮南、北两支潮波在台湾海峡中部汇合,而全日分潮则在台湾海峡南部海域汇合后继续朝西南方向传播。(3)半日分潮振幅最高值发生在福建省湄洲湾—兴化湾一带,全日分潮最高值则出现在雷州半岛以东一带近岸海域。(4)n2、k2和O1、P1、Q1分潮的振幅、迟角分布分别同M2与k1分潮的整体分布趋势相似。Diurnal and semi-diurnal tides in the Taiwan Strait and its adjacent areas are calculated by using a two-dimensional finite-difference model.Compared with data of more than 20 observation stations around the Taiwan Strait,the model-produced results agree quite well with those of previous researches using observational data from coastal tidal gauge stations.According to the results,the co-tidal and co-range charts are given.Furthermore,the characteristics of 8 major tidal constituents have been illuminated respectively.The result shows that:(1) The tide motion can be attributed to the interaction between the degenerative rotary tidal system in the north and the progressive tidal system in the south.(2) The southward and northward tidal waves of semi-diurnal tide converge in the middle of the Taiwan Strait while the diurnal tidal waves propagate southwestward through the Taiwan Strait and the Luzon Strait.(3) The maximum amplitude of semi-diurnal tides exists at the area between the Meizhou Bay and Xinghua Bay,and that of diurnal tides appears in the region to the east of the Leizhou Peninsula.(4) The patterns of co-tidal and co-range charts of N2,K2 and P1,Q1 tidal constituents are similar to those of M2,S2 and K1,O1 tidal constituents,respectively.supportedbytheNationalNaturalScienceFoundationofChinaundercontractNos.40576015;40810069004and40821063;bythekeyresearchprojectofFujianProvinceundercontractNo.2004N203;bytheFujiandemonstratingregionofthe“863”ProjectoftheMinistryofScienceandTechnologyofChin

Research of Software Architecture Based on the Temporal Logic Language XYZ/E (I)——Description of Components and Connectors

XYZ/E是世界上第一个可执行的时态逻辑语言,它既能描述抽象静态语义,又能表示程序的动态语义,这一特征恰好适合分层描述软件体系结构.本文采用XYZ/E语言刻画了软件体系结构的基本组件与连接件;它为进一步描述体系结构风格提供了一个基础

SOBER-SJ10池沸腾现象天地实验研究

SOBER-SJl0是实践十号科学实验卫星19项科学实验载荷之一，通过局部过热在固定位置预定时刻激发产生气泡，并细致观测空间微重力条件下池沸腾现象中生长气泡热动力学过程与传热特征，来揭示沸腾气泡底部细观流动以及传热特性。利用已完成的7次地面实验、1次在轨阶段空间实验以及3次留轨阶段补充实验相关数据，分析了不同过冷度下地面实验沸腾曲线，并通过对天地实验中的沸腾气泡行为及气泡底部加热面温度等结果的对比分析，探讨了微重力环境对相关过程的影响

research on image integral algorithm optimization based on opencl

图像积分图算法在快速特征检测中有着广泛的应用,通过GPU对其进行性能加速有着重要的现实意义。然而由于GPU硬件架构的复杂性和不同硬件体系架构间的差异性,完成图像积分图算法在GPU上的优化,进而实现不同GPU平台间的性能移植是一件非常困难的工作。在分析不同GPU平台底层硬件架构的基础上,从片外访存带宽利用率、计算资源利用率和数据本地化等多个角度考察了不同优化方法在不同GPU硬件平台上对性能的影响。并在此基础上实现了基于OpenCL的图像积分图算法。实验结果表明,优化后的算法在AMD和NVIDIA GPU上分别取得了11.26和12.38倍的性能加速,优化后的GPU kernel比NVIDIA NPP库中的相应函数也分别取得了55.01%和65.17%的性能提升。验证了提出的优化方法的有效性和性能可移植性。国家自然科学基金资助项目(61133005,61272136,61100073)|国家863项目(2012AA010902,2012AA010903)|ISCAS-AMD联合fusion软件中心资助Image integral algorithm is widely used in fast feature detection,and improving the performance of this algorithm through GPU has an important practical significance.However,due to the complexity of the GPU hardware architecture and the architectural differences between different GPUs,how to complete the optimization of this algorithm and achieve performance portability on different GPU platforms is still a hard work.This paper analysed the differences between theunderlying hardware architectures of GPU,and studied the effects of performance on different GPU platforms using different optimization methods from the utilization of the off-chip memory bandwidth,the utilization of the computing resource,data locality and other aspects.And based on this,we implemented the image integral algorithm based on OpenCL.Experimental results show that optimized algorithm gets 11.26 and 12.38 times speedup on AMD and NVIDIA GPU respectively,and the performance of the optimized kernel improves 55.01% and 65.17%than the CUDA version in NVIDIA NPP library,which verifies the effectiveness and cross-platform ability of optimization methods

the design and implementation of a visual software architecture description tool xyz/adl

在时态逻辑语言XYZ/E的基础上,建立一种以可视化图形表示的软件体系结构描述工具XYZ/ADL,它采用组件、连接件及交互端等基本设计单元,可同时描述软件体系结构的静态与动态行为,该语言能在统一的形式框架下完成不同抽象层次体系结构设计之间的逐步过渡,从而将模块化程序设计方法和基于规范的逐步求精方法有机地结合起来