After loading the packages and libraries, the results of the PRJs in directory:

## [1] "Cheng and Cheng 2011.pdf"         "Cody et al. 2002.pdf"            
## [3] "Cook and Cook 2000.pdf"           "Herschel and Jones 2005.pdf"     
## [5] "Nemati et al. 2002.pdf"           "Okhuysen and Eisenhardt 2002.pdf"

Calcualte and visualize tf-idf

Calcualte and visualize Beta

Calculate and visualized Gamma

Calculate and visualize Pairwise Correlation