I. Introduction
In recent decades, data sharing over the internet has been increased rapidly. There are numbers of textual knowledge resources are available publicly. These textual sources can be journal Iconference papers, technical reports, user manuals, blogs, messages on social media and news etc. The amount of data in these resources is huge and growing quickly. An efficient methodology to access and extract information from these resources is required. Text mining is a methodology to automatically process and extract useful information from these resources. This information can be easily used by humans or further processed by other tools and web services. Using text mining approach not only knowledge given in texts could be identified and extracted but also new or implicit knowledge may also be exposed. In recent years, text mining is applied in many areas, such as finding concepts from text and their relations. End users do not have to read huge amount of text and depends only on text mining systems to extract important information from these textual resources.