最小值

The key to feature extraction is to select the optimal feature combination from all the features. In this study, the optimal color feature combination,{/G,(R+4G+B)/6, H variance, S variance}, is selected using genetic neural network at first. Then the main texture features including the mean, variance, energy and entropy of the cooccurrence matrix, the secondary texture features including the maximum frequency number, absolute uniform, inertia and importance of the co-occurrence matrix are extracted.

在此基础上，提出适合多阈值和小目标图像分割的免疫遗传图像分割方法，该方法借鉴了生物免疫系统自调节、抗原识别和记忆功能，并结合了遗传算法对图像进行自适应区域的阈值分割，改善了遗传算法优化复杂问题时存在收敛速度慢和易陷于局部最优的不足，克服了传统阈值分割方法对目标大小的限制，是一种新型的有效的图像分割方法。

Though comparing Canny operator and center B spline dyadic wavelet, the following conclusion is proven in this dissertation: a Center B spline function has tight support and Canny operator hasn't. b Center B spline function asymptotic convergence to Gaussian function and the derivative of Center B spline function asymptotic convergence to Canny operator. c The derivative of fourth order center spline B function is more suitable as a optimal edge detector than Canny operator. d Center B spline function can balance the smoothing and approximation of original data, and the fourth center B spline function is the only optimal solution of two order smoothing problem. e The error between the valve of time-frequency uncertainty of the fourth center B spline function and the lower bound of time-frequency uncertainty does not exceed 0.143% of the lower bound. f The derivative of center spline B function can construct a stability dyadic wavelet and can give a fast algorithm for multiscale edge detection, but Canny operator can do neither.

作者给出了Canny算子与中心B样条二进小波严格的比较证明，得出如下结论：a中心B样条函数具有紧支集，Canny算子不具有紧支集。b中心B样条函数的极限收敛于高斯函数，中心B样条函数的导数收敛于Canny算子。c四阶中心B样条函数的导数比Canny算子更接近最佳边缘检测滤波器。d中心B样条函数比高斯函数更能兼顾对原函数平滑和逼近的折中要求，并且四阶中心B样条函数是二阶逼近问题的唯一最优解。e四阶中心B样条函数的时频测不准关系值与时频测不准关系下界的逼近误差不超过0.143％。f中心B样条函数的导数可以构成稳定的二进小波，存在快速的多尺度算法；而Canny算子不构成稳定的二进小波，无法给出快速的多尺度算法。

Using wavelet transformation technology, singular value decomposition technology and good characteristics of Morlet wavelet in time domain and frequency domain, a de-noising method based on optimal Morlet wavelet and singular value decomposition is put forward.

利用小波变换技术、奇异值分解技术和Morlet小波良好的时域和频域特性，提出了基于最优Morlet小波和SVD的滤波消噪方法。

The optimal thresholds and neighboring window sizes are determined for every subband in the wavelet domain using Stein's unbiased risk estimate, and NeighShrink is also extended from orthogonal wavelet transforms to dual-tree complex wavelet transforms in this paper.

该文运用Stein的无偏风险估计，在小波域每一个子带为NeighShrink方法确定一个最优的阈值和邻域窗口，并将NeighShrink方法从正交的小波变换推广到对偶树复数小波变换。

Under the condition of small strain, the initial value of shear modulus increased along with the increment of angle θ between trail stress paths and recent stress history. If the two directions were entirely reverse, the effect of stress path circumgyration on shear modulus was the largest; if they coincided completely, the effect was very feeble.

研究表明，在小应变范围内，剪切模量的初始值随试验应力路径与近期应力历史间的夹角θ的增大而增大，当两者完全相反时，应力路径旋转对土体在小应变条件下的剪切模量影响最大；完全一致时，其影响最弱。

The method uses maximum between-class variance technique,by the optimization of the niching particle swarm optimization object function,the optimal thresholds can be gotten,and the image by use of the thresholds can be segmented.

该方法基于最大类间方差阈值分割技术，用小生境粒子群算法对适应度函数进行优化，得到最佳阈值，并用该阈值对图像进行分割。

Results After 3 months of kidney radiation by 15 Gy of Cs137 γ-rays, the changes with kidney shrank, Bowman's capsules straitened or disappeared, glomerular swelled, some epithelia denaturalized or died were observed. Mitochondria tumefied and the cristae shortened, lessened and disordered. Urine β2-MP rose evidently. It was lowered significantly the renal 25-OH-D-1α-hydroxylase activity and its mRNA expression. The dry and ash weight, BMD of femur and lumbar were significantly reduced, volume and width of bone trabecula were distinctly decreased and the space increased in model group. The Pyd / Cr increased and ALP decreased as well.

结果 15Gy 137Cs-γ射线肾局部照射3个月后肾脏体积缩小，肾小球肿大，Bowman氏囊囊腔狭窄甚至消失，部分肾小管上皮细胞变性、坏死，线粒体肿胀，体积增大，线粒体嵴变短、减少、排列紊乱；尿β2-MP显著增加；肾1α羟化酶活性及1α羟化酶mRNA基因表达量明显下降；肾辐射组股骨干重、灰重、腰椎和股骨BMD明显降低；骨小梁体积和骨小梁宽度减少，骨小梁间距增加，MAR减小；腰椎压缩和股骨三点弯最大载荷明显降低，Pyd / Cr值明显增加，ALP显著降低。

To increase the security of the watermark, a new binary image encryption algorithm based on TD-ERCS map is presented. The watermark is encrypted by a chaos sequence generated by TD-ERCS map; A novel color image watermarking algorithm is proposed based on discrete chaotic map and 2-dimensions discrete wavelet transform. The watermark is encrypted by the new binary image encryption algorithm, and the encrypted watermark is embed into four sub-bands of the most deep level of blue branch of host image by three-level wavelet transform, and the embedded positions are determined by general cat cha otic map; A novel color-image blind detection watermarking algorithm is proposed based on integer wavelet transform and subsampling. The scrambled watermark is encrypted and embed into the low sub-bands after four sub-images of the Y branch of host image is transformed by two-level wavelet transform, and the embedded positions are determined by Logistic chaotic map, this watermarking scheme can realize blind extraction.

为了提高水印图像的安全性，提出了一种基于TD-ERCS混沌映射的二值水印图像的加密算法，该算法利用TD-ERCS映射产生的混沌序列加密水印图像；将离散混沌映射和二维离散小波变换相结合，研究了彩色图像水印新算法，该算法先对混沌序列加密后的水印图像进行小波变换，再嵌入到宿主图像的蓝色分量的最深层的四个子带中，嵌入位置则由广义猫映射确定；将整数小波变换和图像子采样技术应用于数字水印，提出了一种彩色图像盲提取水印算法，水印嵌入时，先对宿主图像在YIQ色彩空间中的Y分量进行子采样，并对得到的四个子图像分别进行二级离散小波变换，然后将置乱并加密后的水印图像嵌入到小波变换后的低频子带中，其嵌入位置由Logistic混沌映射产生的混沌序列确定，实现了水印的盲提取。

The results show that,in the natural conditions,the intensity of sap flow of Populus populars was 0.088 L·cm -2 ·d -1 .The velocity of sap flow at different depths below the cambium showed the same temporal changes of Populus populars .

结果表明，在正常生长状态下，小美旱杨树干单位面积液流通量为 0 。0 88L·cm- 2· d- 1；形成层以下不同深度的树液流速具有相同的日变化趋势，在中午前后各深度流速值均达到最大，各深度流速差值亦达到最大。

A novel scheme based on wavelet transform and its reversible transform of fault recording data compression in power systems by adopting lifting algorithm is presented in this paper.

利用提升算法实现了一个基于小波变换的电网故障录波数据压缩的新方案，从采样频率的角度首次给出确定最优分解层数的公式，说明了压缩比与频率的关系；结合实际录波数据，选定误差上限后，给出了通用阈值法中参数的优化取值；对比分析了软硬阈值处理方法。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。