Finally the term-document space is constructed by vector space model with term frequency weight . Secondly the latent semantic analysis is studied .

向量空间采用 词频作为权值的向量空间模型构建。其次，研究了潜在语义分析模型。

It trains the neural network ensemble with negative correlation learning method uses tf × idf ( term frequency × inverse document frequency ) system calls encoded mode as the input .

使用负相关法训练神经网络集成，采用tf× idf的系统调用编码方式作为输入。

Ultrashort term frequency forecasting control for a Hydropower Station

水电站超 短期预报 频率控制

The problem of short term frequency stability is one of the key-link techniques in Doppler-velocity measurement .

频率 短期稳定度问题是多普勒测速关键技术之一。

To improve the accuracy of term frequency SBGA employs a new method TFS which takes word sense into account while calculating term frequency .

另外，为了提高 词频计算的精度，SBGA采用了一种改进的词频计算方法TFS，将加权后词的同义词频率加到了原词频中。

This article puts forward the concept of Chinese and English dictionary with reverse term frequency .

提出了带反向 词频的中英文词典这一概念。

Retrieve the entries affect the same proportion in the document term frequency weighting term .

检索词条在文档的比重同样影响 词条的权重计算。

This paper presents the weight calculation based on term frequency by analyzing the important effects of E-mail character field in topic expression and improves the traditional probabilistic model of resemblance calculation .

分析了邮件特征域在邮件主题表达力方面的重要作用，给出了基于 特征域 词频TF的权值计算方法，并改进了传统的文本相似度计算概率模型。

We can use term frequency to have a weighted calculation and improve traditional text similarity calculation probability model in SVM algorithm .

通过利用基于 词频的权值计算，同时改进传统文本相似度计算概率模型，改进SVM算法实现邮件过滤系统。

A Novel Detective Method for Fundamental Current and Any Term Frequency Harmonic Current

基波电流和 任意 次数谐波电流检测新方法

According to the data of the atomic time within 2.25 years ( from October 1985 to December 1987 ) we compared the Joint Atomic Time of China ( JATC ) with the atomic time of various nations in the long term frequency stabilities .

根据2.25年内（从1985年10月到1987年12月）的原子时数据，本文对综合原子时（JATC）和各国原子时的 长期 频率稳定度进行了比较。

Both short and long term frequency stabilities of the simultaneous oscillations are better than several Parts 1010 .

它可使同时振荡的双波长之 频率稳定度不论短周期或长 周期都优于10－10。

Application of Weight Calculation Based on Term Frequency for E-mail Filtering

基于 词频的权值计算在邮件过滤算法中的应用

The Long Term Frequency Stability in the GPS Time Comparison

GPS时间比对的 长期 频率稳定度

In this paper the difference between the short term frequency stability of a pulse Doppler radar and that of a continuous-wave system is discussed in detail and a set of approximate formulas is presented .

文中详细讨论了脉冲测速雷达的 频率 短期稳定度与连续波时的差别，并给出近似计算公式。

Measurement of short term frequency stability and phase noise of frequency source

频率源的 短期 频率稳定度及相位噪声测量

Traditional algorithms only consider about TF ( Term Frequency ) IDF ( Inverse Document Frequency ) and so on and do not consider DI ( Distribution Information ) among and inside classes and LFHW ( Low Frequency but High Weight ) terms .

传统的特征 权重算法着重于考虑 频率和反文档频率等因素，而未考虑特征的类间、类内分布与低频高权信息。

Treatise on the problem of short term frequency stability in Doppler-velocity measurement

多普勒测速的 频率 短期稳定度问题

The paper present feature evaluating function based document frequency with minimum term frequency threshold to reduce the proportion of noise features and improving the quality of text categorization .

利用最小 词频阈值的文档频特征评估函数减少噪声特征的比例，提高文本分类的质量。

The Requirement of Short Term Frequency Stability of RF Pulse Train for COR MTI and MTD Radar

COR、MTI、MTD雷达对射频脉冲序列 频率 短稳的要求

Current feature selection algorithms are all based on term frequency and ignore the class information in the training sample set . A new feature selection algorithm based on class information was put forward .

目前的索引 词选择算法大多是基于 词频的，没有利用训练样本中的类别信息，为此提出了一种新的基于类别的特征选择算法。

In the method lexical chains are firstly constructed by calculating the semantic similarity between terms then keywords are selected through taking account of term frequency and area .

该方法考虑了 词汇之间的语义信息，能够改善关键词 标引的性能。

Based on it we doa deep research on the space distribution and time distribution from the view of term frequency mutual information and word similarity .

在此基础上，我们进行了新词特征的挖掘，从串 频、互信息和相似度等角度主要对 新词的空间分布规律和时间分布规律进行了分析。

The short term frequency stability of the phase locked oscillator was about 10-9 in 1s the long term frequency stability was about 10-7 . The output power was measured to be greater than 30 mW with more than 120 MHz reliable locked operation range .

整个锁相源的秒级频率稳定度为10~（-9）量级， 长期 频率稳定度为10~（-7）量级，能够可靠入锁的频率范围大于120MHz，输出功率大于30mW。

Therefore a text categorization algorithm based on frequent patterns with term frequency is presented .

为此，提出了基于分类规则树的带 词频的频繁模式文本分类方法。

This paper compares several feature selection methods in text categorization proposes a new feature selection method based on term frequency and inverse document frequency .

本文在分析比较几种用于文本分类的特征选择方法的基础上，提出了一种基于 术语 频率和逆文档频率的特征选择方法TDF。

This paper discusses the existent typical ranking technologies of term frequency count and hyperlink analysis in virtue of vector space model the author proposes a new ranking technique document similarity ranking with a basis on similarity of concept-semantic query term .

对现存典型的 词频统计排序技术和超链分析排序技术进行了分析，并借助向量空间模型，提出了一种基于概念语义的查询词-文档相似度排序方法。

The results show that it has better short term frequency stability and frequency drife performance with temperature .

试验表明，它具有良好的 短期 频率稳定度和温漂特性。

An ultrashort term frequency forecast of the system frequency is made for the hydropower station and the results have been applied in computer frequency control of the hydropower station .

本文对主 调频水电站进行系统频率超 短期预报，并把预报结果直接应用于水电站的计算机频率控制。

Effect of Short Term Frequency Stability of Oscillators on the Velocity Precision in a TT & C System

测控系统中 振荡器 短稳对测速精度的影响