查询词典 variable compression ratio

The main work and innovation1 In general , a image compression method has different effect to different image . Some are fit for image which has much high frequency . Some are fit for image which has much low frequency .This paper analysis the applicability of fractal algorithm . In this dissertation , an improved algorithum is given . The basic algorithum without eight change and the joint use of quantitative coding , The compression ratio and PSNR can be adjusted , and it can get more quickly speed of coding .2 To a group of exact fractal code , the decoding image can be any resolution .With this characteristic ,choose the proper domain block and range block,this paper get an algorithum which can get higher decoding PSNR and speed than the basic fractal algorithum.3 Give a new method to calculate the scale factor . The calculation of basic algorithum is complex and enormous . The factor of scale is an important variable of the basic algorithm. Now there are two methods to calculate the factor of scale .A new method was given to calculate the factor of scale. The calculation load and complexity are reduced by the new method. Compared with the basic algorithm , the method can reduce coding time.4 The basic fractal algorithum is based on the Collage theorem and contraction mapping theorem . A mathematic model based on basic fractal algorithum is given .

本文的主要工作及创新点主要包括以下几点：1一般情况下，一种图像压缩的方法对不同特点的图像，压缩效果会有所不同，本文利用分形压缩编码对不同特点的图像进行编码，分析了分形编码对不同图像的编码适用性，利用去掉8种变换的分形编码算法与简单的均匀量化编码方案相结合，得到了一种可以调节压缩比与解码质量的分形编码方案，该提高编码速度6倍以上。2分形编码的特点之一是分形解码的分辨率无关性，即对于一组分形编码可以将其解码到任意分辨率下，本文利用分形编码的这一特点，结合不同的量化编码方案，选择合适的定义域块与值域块及适当的编解码分辨率，得到了一种提高解码质量，编码速度提高12倍以上的加速算法。3比例因子是基本分形算法中的一个重要变量，目前有两种计算比例因子的方法，文中给出了一种新的求比例因子的方法，该方法简化了求比例因子的计算，从整体上减小了基本分形算法的计算量，简化了算法4分形压缩的数学基础是不动点定理与拼贴定理，本文根据基本的自动分形编码方法，建立数学模型对其进行推导，得到了用普通数学的极限理论解释分形编码的数学表达式，从而对由基本分形编码得到的解码图像中的像素点的值给出了确定的表达式。

This represents a fundamental mathematical limit on the best possible lossless data compression of any communication: considering a certain message as a series of realisations of a certain random variable (where the random variable can be "the next letter", or "the next word", or any other subdivision of text), the shortest number of bits necessary to transmit one message is the Shannon entropy of the corresponding random variable, multiplied by the number of realisations in the original text.

当然如果各个队夺冠的几率不等的话，那么熵则不会是5。因为如果从强队开始问问题，则不需要5个问题一般就可以得到答案。而根据哈夫曼编码的启发，我们表示这32个队，不需要平均长度为5的二进制位。从另外一个角度来看，熵作为信息量的大小也是表达能力的衡量，或者是不确定度的衡量和混乱程度的表现。为什么选择log来表示熵呢？如果X的表达能力为H，Y的表达能力为H，那么X+Y的表达能力应该是二者的乘积，所以H = H + H。

The rest reside among the populations. and that about 80.98% of 12 double chromosomal variability in arm ratio existed within the populations. The rest reside among the populations. Nested random effects analysis of variance for variable the relative length, arm ratio of chromosome, the mean of ratio (largest/smallest), mean ratio of ann. As. K. and actual length of genome of chromosome. As a resuit, chromosomal structure variations was 96.36% within the populations.

结果］在相付长度方面，香水百合12对染色体变异约有88.91%来源于居群内，约有11.09%来源于居群间；在臂比方面，香水百合12对染色体变异约有80.98%来源于居群内，约有19.02%来源于居群间；在染色体长度比、平均臂比、核型不对称系数和染色体组实际长度方面，香水百合染色体变异约有96.36%来源于居群内，约有3.64%来源于居群间。

Discuss the influence of the factors of section forms(different ratios between limb length with limb width), the reinforcement that adjusts the bellyband ends, and the existence of stirrup on the limited values of axial compression ratio of the T, L shape section columns, and draw the variation law of the limited values of axial compression ratio along with the variation of theabove-mentioned factors.

讨论了截面形式、改善腹板端部的配筋、以及箍筋的存在等因素对T、L形截面柱的轴压比限值的影响，得出了轴压比限值随上述因素的变化规律。

For reducing boundary distortion area, the elevations of grid DEM are viewed as a discrete sequence under a generalized coordinate, so that the boundary problem of two-dimensional discrete wavelet transform is turned into the boundary problem of one-dimensional discrete wavelet transform, which not only greatly reduces the boundary distortion area, improves the precision of reconstructed DEM data near the boundary, but also decreases the number of zeros adding on the boundary for wavelet transform, and boosts the compression ratio. On the basis of analyzing the distribution characteristics of coefficients in low and high frequency bands, a mixed entropy coding plan is applied, and a high efficient quantizator called"self-adaptive hard threshold"is established, which is helpful for improving the precision of the reconstructed DEM data and for enhancing compression ratio.

为了减小小波变换山区格网DEM数据压缩中边界失真区域，将山区格网DEM高程值视为广义坐标下的离散随机序列，把二维离散小波变换中的边界问题转换为一维离散小波变换中的边界问题，不仅大大减少了小波变换边界失真区域，提高了重构DEM数据边界点的精度，而且减少了边界补零个数，提高了压缩比；通过对山区格网DEM数据小波变换低频区和高频区变换系数分布特点的分析，采取了霍夫曼—游程混合熵编码方案，设计了高效、低失真的"自适应硬阈值"量化器，即对低频区变换系数不进行量化，直接进行霍夫曼编码；对高频区变换系数则先用"自适应硬阈值"方法量化处理，再进行游程编码。

The results show that the chip thickness compression ratio decreases with the increase of undeformed chip thickness, and particularly, the chip thickness compression ratio is less than 1 under most experimental conditions.

第五，研究了KK合金在切削过程中的摩擦行为及其机理，发现切削时前刀面上的摩擦主要是在紧密型接触的条件下进行的。

Finally three kinds of usual methods to determinate the limit values for axial compression ratio of frame columns, their merits and shortcomings are analyzed according to comparison and in the end this paper adopts the measure of curvature ductility to determinate the limit values for axial compression ratio of the arbitrarily inequiaxial special-shaped R.C columns.

最后介绍了目前确定框架柱轴压比限值常用的三种方法，并对比了三种方法的优缺点，最终采用延性度量的方法确定了不等肢异形柱的轴压比限值，对实际工程具有很好的参考价值。

The results of this study indicate that changing the angle of the intake port has a profound effect on the flow field during the intake stroke of the engine cycle. For the case with the intake-exhaust valves canted at zero degree (the so-called vertical valves), the tumble ratio, swirl ratio, turbulent intensity, and turbulent kinetic energy in the direction perpendicular to the bisecting plane of the cylinder are at their highest levels than those obtained for the other cases. This effect is most pronounced after the compression stroke of the cycle. As a result of this study, it is observed that the behavior of the overall flow field from the intake to the completion of compression stroke has a major impact on the effectiveness of the mixing of fuel-air prior to the ignition of the engine cycle.

结果显示，改变进排气阀的倾斜角度对进气期间的流场变化有很明显的影响，其中以垂直阀(进排气阀倾斜0度)所得的 Y轴向(Y方向系垂直於将汽缸对分为二平面的方向)滚流强度、涡漩比、紊流强度、紊流动能等流场强度为最强；若以流体经活塞压缩后的流场特性进行探讨，所得结果显示压缩冲程对汽缸内流场的效应是不容忽视的；因此由进气到压缩过程结束的整体流场现象，才是影响引擎点火前的油气混合程度与燃烧品质的关键。

You can simply select DXT1 for a 1:6 compression ratio for color textures and DXT5 for a 1:4 compression ratio for textures with alpha information.

你可以为彩色的纹理选择使用DXT1格式来获得1：6的压缩率，或者为带有alpha信息的纹理使用1：4压缩率的DXT5格式。

The strengths of the plain wood rose along with the compression ratio, while the bending strength and MOE lowered as it reached the maximum compression ratio; the plain wood compressed (33%) and heated 10h with 180℃. its bending strength lowered 40%, MOE lost about 50% and hardness lowered 12% than heated 0.5h; the properties not to be compressed after impregnated with PF resin. had a slow rising with the resin concentration, and compressed (33%) after impregnated with PF resin (30%). its bending strength, MOE and hardness increased 82.9%, 98% and 152% respectively.

三倍体毛白杨素材压缩后，其静曲强度和抗弯弹性模量均随压缩率的增大而提高，但接近最大压缩率时均下降；素材压缩（压缩率为33%）后以180℃空气加热处理10 h，静曲强度比同温度压缩保温0.5 h时下降约40%，抗弯弹性模量下降近50%，表面硬度下降约12%；用PF树脂浸渍处理后不经压缩，随PF树脂含量增加木材静曲强度提高幅度不大；用30%PF树脂浸渍后，当压缩率为33%时，其静曲强度、抗弯弹性模量和表面硬度分别比未压缩素材增加82.9%，98%和152%。

Chimborazo and Cotopaxi, took me by the hand.

越过琴博腊索山和科托帕克西山。

This car is in a good condition.

这辆车的状况很好。