Entity Knowledge Base Creation from Czech Wikipedia

C­lem t©to prce je navrhnout a implementovat syst©m pro automatickou extrakci pojmenovanch entit z text Äesk© Wikipedie, vytvoit znalostn­ bze tÄchto entit a vyhodnotit spÄnost a vsledky vytvoen©ho syst©mu. Prvn­ Äst prce vysvÄtluje zkladn­ pojmy z t©to oblasti zpracovn­ pirozen©ho jazyka a informuje o existuj­c­ch syst©mech podobn©ho charakteru. V stedn­ Ästi je popsn vlastn­ nvrh nÄkolika metod extrakce a zpsobu implementace tÄchto metod. K extrakci byly vybrny tyto entitn­ typy: osoby, m­sta, udlosti a organizace. V zvÄru jsou popsny vsledky prce, tedy spÄnost jednolitch metod u dan©ho entitn­ho typu a statistiky extrakce jednotlivch entit vztaen© k celkov©mu sloen­ Äesk© Wikipedie.The aim of this thesis is to propose and implement a system for an automatic extraction of named entities from Czech Wikipedia, to create a knowledge base consisting of these entities and to evaluate results of the created system. The first part explains basic notions of this field and discusses related work. The main part proposes several methods of extraction and details their implementation. The following types of entities are extracted: people, places, events and organizations. The final part of the thesis presents results, i.e., the success of the individual methods for each entity type and statistics on extraction of the individual entities in the whole Czech Wikipedia context.