变换器

Blend various advantages of the coding project of the parameter audio frequencies in the meantime, carried on adjustment on the coder structure, have to a certain signal more the mold piece of coding result, if wave structure analytical transformation short time of the mold piece, double the composition examine and double the transformation short time mold piece etc. is an options to bring into coder, from user while coding according to small together source voice document of small together characteristics, decide whether use and how use, but these vivid constitutions can through a code flow in define several good to mark ratio in advance tell a decoding machine especially, constituting decoding machine is little with complications to without direct influence.

同时融合多种参数音频编码方案的优点，在编码器结构上进行了调整，将只对某类信号有较好编码效果的模块，如谐波结构分析模块、双变换短时成分检测与双变换短时模块等，作为选项纳入到编码器中，由使用者在编码时根据小同源声文件的小同特点，来决定是否使用和如何使用，而这些灵活的设置都可以通过码流中预先定义好的几个标示比特位来告知解码器，对解码器本身的构成与复杂度少没有直接的影响。

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。

In every period, do the following operations:# For each 8*8 block, do the discrete cosine transform, then take out direct current coefficient in each block, using the transformation above for each DC coefficient, the gold stands for the code of the spread-spectrum we use when embedding the different watermark bit in different frames, after all of the watermark information which we want to embed is embedded, then do the inverse discrete cosine transformation, and store the current frame in a new file.

于是利用DCT变换域的这点重要的几何不变性，我们可以推导出一种能够抵抗几何攻击的视频水印算法，即将所需要嵌入的水印信息以127位扩频序列作为辅助，以求和值形式嵌入到DCT变换后的每个宏块的每个DC系数当中，具体嵌入和提取算法如下：根据使用的扩频序列的长度N，基于相关的嵌入器需要选取包含N帧的视频子序列，令这N帧视频子序列作为一个嵌入周期，对于每N帧视频子序列做如下的操作，#即对于每个8×8的像素块进行DCT变换，然后取出每个DCT变换后的直流分量，对于每个DC系数，做如上所述的变换，其中gold为在第k帧中嵌入第i位水印信息时使用的扩频码字值，待将所有需要嵌入的水印信息全部嵌入后，再做反DCT变换，保存当前帧。

Synchronous rectifying teehnology is intr...

同时，介绍了能提高变换器效率的同步整流技术。

The power loss of the electrical driving system has been measured under different exciting current of the motor and duty cycle of the dc converter.

并针对不同负载下系统稳态损耗和电机励磁电流和直流变换器占空比的关系进行了实验研究。

According to this converter many new topologies are induced, and its general structure is synthesized.

在此变换器的基础上，还可以对其拓扑扩展，推导出一系列新的拓扑，总结出其三端通用结构。

First, the principle and the topologies of sin...

首先，针对单相DC/AC变换器，分析了它们的主电路拓扑结构、工作原理以及脉宽调制方式。

In chapter 2, the soft switched inverter topologies for high power multi-phase applications are studied.

在第二章中，对适用于VSCF电源的软开关变换器拓朴进行了研究。

This paper analyzes and synthesizes the current topologies of single-stage PFC DC/DC converters with the direct power transfer technology,and describes mechanism and implementation of the DPT technology.

本文对现有的应用直接功率转换技术的单级 PFC AC/DC变换器进行了深入的分析和综合，阐明了它们的直接功率转换的机理和实现方法。

The steady state of CDR converter is analyzed. The equivalent circuits and corresponding formulas are proposed in each mode of overall 12 modes.

对倍流整流的全桥移相变换器作了稳态分析，给出了12个运行模态的等效电路和电压电流公式。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐