不使逼近

It has been deduced that the search direction remains the same but that the step length decreases in optimizing the improved cost function with the conjugate gradient algorithm from the gradient of the cost function that the FIR filter apporaches the contrary point spread function more, and that the estimated image is closer to the original one.

从代价函数的梯度入手推导出共轭梯度算法，其搜索方向保持不变而搜索步长变小，使滤波系数更加逼近于点扩展函数逆算子，从而使估计图像与原始图像更加接近。

The kernel is adding a discontinuous function for the standard approximation to account for the crack. A feasible technique is adopted for dealing with multiple cracks and intersecting cracks.

本文研究扩展有限元方法，通过改进标准有限元的单元逼近函数，使之能够表达单元内的几何不连续，从而实现切割和断裂的模拟。

In order to draw a photorealistic surface, Bidirectional Texture Functions, a 6D texture function which extends Bidirectional Reflectance Distribution Function to include the self-shadowing, self-occlusion and inter-reflection effects, has been mentioned frequently in recent years. Its main drawback is its massive data size. To solve this, Spatial Bidirectional Reflectance Function techniques compress BTFs into reflectance model parameters. However, SBRDF cannot producethe self-shadowing and self-occlusion effects in real-world surface geometry. This work is aimed to this drawback. I find how self-shadowing and self-occlusion affect the surface by additional physical-based analysis. And I rely on two physical phenomena to divide self-shadowing and self-occlusion into two independent effects. First, self-shadowing is view independent. Second, self-occlusion is independent of lighting direction changes. After these analyses, I use SBRDF and additional self-shadowing and self-occlusion I found to render a photorealistic surface as non-compressed BTFs doing.

为了把物体表面呈现的更真实，六维函数BTFs ( Bidirectional Texture Functions)目前已经被使用的相当频繁，但BTFs的资料量实在太大而没办法直接使用，为了解决资料庞大的问题，传统的SBRDF以逼近光反射模型参数，来达到资料压缩的效果，但是SBRDF对於表面的凹凸所产生的阴影及遮蔽，不能达到逼真的呈现，为了改善这个问题，我们选择从物理方面，找出资料中阴影和遮蔽等属於表面几何的资料并去除，使参数更正确，同时利用两个物理现象去区分阴影及遮蔽为两个互不干涉资料，第一是阴影不会因视角不同而改变，第二是遮蔽不因光线方向不同而改变，经过这些分析，我可以利用SBRDF加上附加的阴影及遮蔽两种独立的效应，来达到彷佛跟未压缩过的BTFs一样的真实绘图。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。