一种基于改进互信息的文本分类方法

用改进的互信息公式进行特征选择,通过三种文本分类方法验证了改进的公式具有较高的准确率、召回率和F1值,从而证明改进的互信息公式的有效性.     

On the predictive ability of narrative disclosures in annual reports

We investigate whether narrative disclosures in 10-K and 10K-405 filings contain value-relevant information for predicting market performance. We apply text classification techniques from computer science to machine code text disclosures in a sample of 4280 filings by 1236 firms over five years. Our methodology develops a model using documents and actual performance for a training sample. This model, when applied to documents from a test set, leads to performance prediction. We find that a portfolio based on model predictions earns significantly positive size-adjusted returns, indicating that narrative disclosures contain value-relevant information. Supplementary analyses show that the text classification model captures information not contained in document-level features of clarity, tone and risk sentiment considered in prior research. However, we find that the narrative score is not providing information incremental to traditional predictors such as size, market-to-book and momentum, but rather affects investors’ use of price momentum as a factor that predicts excess returns.     

基于SED1330液晶控制器的多种显示技术及其实现

介绍了液晶显示屏开发中的各种显示技术，实现了汉字的图形方式显示、数字及符号的文本方式显示，静态图片显示、实时曲线的动态显示等多种显示方式的软件设计，提出了一种便于观察整体趋势的曲线压缩技术及其关键编程技术，使测控系统中对被测参数的精确显示及参数趋势的形象化观察得以实现。