查询词典 geometrical vector

The whole process of text representation were discussed — word segmentation, building stop words list, feature selection, weight computation and generating vector space. Aim at the influence of stop words, a list, which is fit for text categorization, is set up and makes the vector dimension reduce.

针对停用词对分类的影响，建立了适合文本分类的停用词表，使向量维数得到初步降低；对现有特征选择方法进行了介绍和对比，构造了一种适合支持向量机的特征选择函数——基于类内频率的特征选择函数。

A simulation research is conducted on the example of six-phase double star winding shifted by 30°synchronous motor.In order to investigate the control algorithm of multilevel inverter , high harmonics as well as its problems, a mathematical model of the control algorithm based on the voltage space vector is built. For the first time, the principle along boundary is introduced to confirm the chosen switch state when many switch states are corresponding to the same vector. Simulation analysis and hardware realization are conducted with the combination of diode clamped three-level inverter and five-level inverter.

建立了基于空间电压矢量控制算法的仿真模型；仿真研究中采用对偶小矢量搭配改善中点电位波动的问题；针对多个开关状态对应同一待选矢量的问题引入&循边原则&确定被选择的开关状态；对过调制问题进行了相应的处理：结合二极管嵌位式三电平逆变器和五电平逆变器进行了仿真分析和硬件实现。

Secondly, to reduce the error cumulating effect of LAG-BA, another bit-allocation algorithm was derived from the least square support vector machine, where the coding information of several similar frames was taken into account. The proposed algorithm is denoted least square support vector machine bit allocation, which further depresses the video quality fluctuation.

针对LAG-BA的误差累积效应，根据最小二乘支持向量机的原理，进一步提出了一个考虑到多个相关图像编码信息的目标比特估计算法，并用LAG-BA和LSSVM-BA取代MPEG-4 Q2方案中的比特分配算法设计了两个改进的MPEG-4 Q2方案。

In VQNN, the dynamic programming method is introduced to estimate the initial value of the speech sample vector cluster center and to determine initial weight matrix, and the code vector that is 256 quantization degrees is built.

VQNN 中引入了动态规划法估计语音样本矢量的码本类中心初值并确定网络的初始权矩阵，可构造出256 个量化等级的码本矢量。

Minimum time required for acquisition and inoculation of geminiviruses by the whitefly is 15-30 min Geminiviruses may be retained in their vector for one to several weeks, and sometimes for the entire life of the vector.

烟粉虱最短的获毒和接种时间为15~30min；双生病毒在烟粉虱体内可存留1至数周，有的终身存在。

On CHE programming, the higher coupling ratio of control-gate makes the higher electrical field across TOX in Si than Ge. Also because of the continuity of displacement vector, the higher permittivity of Ge would cause the lower electrical field at interface. We get the higher gate current in Si than Ge. On CFN programming, the higher CT in Ge would show the higher electrical field across TOX. However, the parameters of F-N tunneling are calculated and showing the gate current in Si is larger than Ge. On the same mechanism of F-N tunneling erasing, the parameters also show the higher electrical filed of Si would cause the higher erasing speed. The continuity of displacement vector also explains the higher electrical field at interface for F-N tunneling programming/erasing.

从通道热电子穿隧写入的模拟结果发现，由於控制闸极耦合电容的影响，加上电位移向量在半导体-氧化层界面连续的观念，拥有较高介电常数的锗反而得到较小的等效电场，决定了穿隧电流反倒是不如矽基板；在F-N穿隧写入的模拟中，即便锗基板拥有较大的总耦合电容，使得在浮闸的耦合电压大於矽基板，但仍旧是半导体-氧化层界面的电场扮演了穿隧电流的决定性因素，得到的结果仍旧是矽基板的写入速度高於锗基板；在F-N抹除的模拟中，运用与F-N写入相同的数学模型，仍旧看见在锗基板上未能得到速度上的改善，同时用数学的计算展示了合理的解释。

The time-history velocity response signal of pile can be decomposed by Sym wavelet. The power spectrum value can be extracted from some specified spectrum range. These values from one signal makes up the characteristic vector representing this signal. The relationship between characteristic vector of pile and pile defect type can he established by using BP artificial neural network. Abundant time-history velocity response signals of pile can be acquired by numerical simulation method.

利用Sym小波对基桩速度响应时程曲线进行小波分解，对指定频带上的信号分量进行特征值提取，提取的特征值为反映各频带范围内体现能量分布的功率谱均值，提取的特征值可构成反映信号特征的特征向量，同时利用BP人工神经网络的非线性映射特性建立特征向量和基桩缺陷类别之间的一种对应关系。

Let's take the Oryza sativa single-cross homologous recombination chloroplast expression vector pRSMGA which was constructed with seven fragments as an example, if the vector pRSMGA was constructed in using the method what had mentioned, only twice recombination and transformation would be done.

以7片段拼接的水稻单交换质体定点整合表达载体pRSMGA的构建为例，应用上述方法构建只需做两次连接、转化，且其重组、转化效率高。

The method is realized via the following steps: first to apply Isomap or LLE to get the embeddings of the original data set in the low dimensional space; then to obtain support vectors, which are the most significant and intrinsic data for the final classification result, by using support vector machine on these low dimensional embedding data; subsequently to get support vectors in the original high dimensional space based on the corresponding labels of the obtained low dimensional support vectors; finally to apply support vector machine again on these high dimensional support vectors to gain the final classification discriminant function.

数据挖掘是数据库知识发现中最重要的步骤之一，其目标是从获取的数据中高效准确地挖掘出我们所需要的信息。在实际应用中，数据往往呈现海量、高维、非线性等特性，这些特性给数据挖掘带来了很多问题，例如海量特性导致的计算效率低下问题、高维特性带来的维数灾难问题和非线性特性引起的线性模型失效问题等。幸运的是，实际中高维数据的属性之间往往存在一定的规律性和相关性，即实际数据经常存在着外在与内在两个维数。

Finally, the constructed β3AR gene antisense expression vector was identified though restriction endonuclease analysis and sequencing. RESULTS: Target gene of about 1.2 kb was successfully cloned into retroviral vector pLNCX. The sequence of cloned β3AR fulllength cDNA was identical to the reported one in GenBank.

结果：经琼脂糖凝胶鉴定，所克隆的目的基因大约为1.2 kb，并成功地连接到逆转录病毒载体pLNCX上，经测序证明，插入的目的片段其碱基序列与Genbank上报道的完全一致，且插入载体的方向完全正确。

More direct, directer ; most direct, directest

径直的，笔直的

Do you know how to use a chain saw?

你知道如何使用链锯吗？