中文摘要：

基于词的向量空间模型是文本分类中的传统的表示文本的方法。这种表示方法的一个缺点是忽略了词之间的关系。最近一些使用潜在主题文本表示的方法，如隐含狄利克雷分配LDA（Latent Diriehlet Allocation）引起了人们的注意，这种表示方法可以处理词之间的关系。但是，只使用基于潜在主题的文本表示可能造成词信息的损失。我们使用改进的随机森林方法结合基于词的和基于LDA主题的两种文本表示方法。对于两类特征分别构造随机森林，最终分类结果通过投票机制决定。在标准数据集上的实验结果表明，相比只使用一种文本特征的方法，我们的方法可以有效地结合两类特征，提高文本分类的性能。

英文摘要：

Term-based Vector Space Model （VSM） is a traditional approach to representing documents, which defects in its neglecting of the relations between terms. To capture the relations hetween the terms, some latent topicsbased document representations such as LDA （Latent Dirichlet Allocation） have arisen much attention recently. However, simple latent topic-based text representations may cause loss of information carried by terms. In this paper, we use a modified random forests method to combine the term based and the LDA latent topic based documents representation. Random forests are constructed separately for two kinds of text representations and the final classification result is decided by vote scheme. The experimental results on some standard datasets show that, compared with methods only using one set of text features, our method can efficiently combine two kinds of text representations and improve the performance of text categorization.