tailieunhanh - Semantic Web Technologies phần 2

cũng có thể được sử dụng trong một số giai đoạn khác của quá trình xây dựng bản thể học bán tự động, chẳng hạn như đánh giá bản thể học hoặc sàng lọc bản thể học (giai đoạn 5 và 6, mục ), ví dụ | USING KNOWLEDGE DISCOVERY FOR ONTOLOGY LEARNING 19 learning scenario 5 in Section . Collecting data relevant for the existing ontology can also be used in some other phases of the semiautomatic ontology construction process such as ontology evaluation or ontology refinement phases 5 and 6 Section for instance via associating new instances to the existing ontology in a process called ontology grounding Jakulin and Mladenic 2005 . In the case of topic ontologies see Chapter 7 where the concepts correspond to topics and documents are linked to these topics through an appropriate relation such as hasSubject Grobelnik and Mladenic 2005a one can use the Web to collect documents on a predefined topic. In Knowledge Discovery the approaches dealing with collecting documents based on the Web data are referred in the literature under the name Focused Crawling Chakrabarti 2002 Novak 2004b . The main idea of these approaches is to use the initial seed information given by the user to find similar documents by exploiting 1 background knowledge ontologies existing document taxonomies etc. 2 web topology following hyperlinks from the relevant pages and 3 document repositories through search engines . The general assumption for most of the focused crawling methods is that pages with more closely related content are more inter-connected. In the cases where this assumption is not true or we cannot reasonably assume it we can still use the methods for selecting the documents through search engine querying Ghani et al. 2005 . In general we could say that focused crawling serves as a generic technique for collecting data to be used in the next stages of data processing such as constructing ontology learning scenario 4 in Section and populating ontologies ontology learning scenario 3 in Section . . Data Visualization Visualization of data in general and also visualization of document collections is a method for obtaining early measures of data quality content and .