جغرافي الأنظمة دولي القومي المنطقة الحرية السياسية...

جغرافي الأنظمة دولي القومي المنطقة الحرية السياسية Geographic Systems International National Area Liberty Politic (a) حرق سلاح ميليشيات مواجهات انفجار قتل عنف Burn Weapon Militias Clashes Explosion Kill Violence (b) مسؤول الشعوب حكومة شارك قرار القوى Responsible Peoples Government Share Decision Forces (c) Figure 3: (a) Some frequent words in politics documents, (b)Some frequent words in violence documents, (c)Some common in violence and politics documents These documents are located into two subfolders called "Politics" and "Violence" in a "DATA" folder and the path of this folder is passed to the next phase to start working on these documents.

Data pre-processing In this phase, documents are processed and prepared to be used by the classification phase. This phase has three main sub-phases; Tokenizer, Stemmer, and Feature extractor Tokenization Tokenizer is responsible for scanning each document word by word, and extracting words in this document. It has two main steps; tokenization and text cleaning.

In the tokenization, the Arabic Tokenizer uses White Space Tokenization because the space is the only way to separate words in Arabic language, i.e. dash and hyphen are not used to separate words in Arabic. Then in the text cleaning step, it removes the non-Arabic letters, numbers and punctuations as shown in Figure 4. Figure 4: Tokenization example It also removes the stop works such as stop words pronouns, conjunctions, and prepositions. As well, it removes numbers, and names.

In Arabic, identifying and removing names is not an easy task like that in other languages.In English for example, the capital letter are used for identifying names and abbreviations in the middle of sentences, while in Arabic, the concept of capital letters does not exist at all. Another problem is that most Arabic names actually come from verbs and could be stemmed to regular stems, also Arabic names and could be used as adjectives or other parts of the sentences.

The most suitable technique for identifying names may be based on sentence analysis. But the problem facing these techniques is the complexity of Arabic. i.e. the basic sentence structure for Arabic is very flexible and may take the form of "Subject Verb Object" , "Verb Subject Object" or "Verb Object Subject", the basic Arabic sentence can take any of these three forms. This is a simple example of the complexity of Arabic sentence structure.