Browsing by Author "Teferi, Dereje(Dr)"

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    Ontology Based Query Expansion For Enhancing The Performance of Amharic Information Retrival: The Case of Tourism Sector
    (Addis Ababa University, 2014-10-05) Janfa, Welde; Teferi, Dereje(Dr)
    The availability of a plenty of information and knowledge sources has demanded a large amount of effort in the development and enhancement of Information Retrieval techniques. Query expansion has been one of the important techniques in an information retrieval area in order to increase the efficiency and effectiveness of the search engine. Query expansion, improves the performance of the IR system by augmenting additional word to the user query from the given knowledge source. Adding additional power full words to the user query helps to generate more useful information to the user. This research focuses on automatic query expansion mechanism to increase the searching power of the user query. Many types of query expansion have been applied and tested to facilitate the information retrieval process. In this research work, an attempt is made to integrate an ontology based query expansion technique to enhance the effectiveness of the system in retrieval process. Ontologies are usually huge repositories of concepts and relations between concepts in a certain domain. Using the ontologies in information retrieval improves the retrieval goal. The aim of this research is to explore the impact of the use of ontology for query expansion to improve retrieval results. Small size domain specific corpus dependent ontology is constructed and used in the proposed query expansion model. Experiments are carried out on the system before and after integrating the proposed techniques. The results show that ontology based query expansion has resulted in a higher number of relevant documents being retrieved compared to other query expansion process. Overall, ontology based query expansion improves recall by 42% and system performance by 7%. The major challenge is constructing domain specific ontology and corpus that is an important element in this research which needs more work in the future.
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    Practices, Challenges and Prospects of Informaiton Secuirty Policy in Ethiopian Banking Industry
    (Addis Ababa University, 2015-03) Negussie, Abeselom; Teferi, Dereje(Dr)
    Information is one of the primary assets of any organization. Thus in today’s business environment any organization depends on information and information technology. Information security has become the major concerns and challenges facing any organization. Ethiopian banking industry is one of the rapidly growing industries in the country with the advancements of information technology. This thesis work assesses how Ethiopian banking industry’s information security and information security policy practices is. This research answers the following research questions: how is the current practice of information security and information security policy in Ethiopian banks? What are the challenges in formulation, implementation and compliance of information security policy in Ethiopian banks? What are the future prospects of Information security policy in Ethiopian banks? Assessing the practices of information security and identifying the challenges of information security policy helps the banking industry to formulate and implement their information security policies efficiently and effectively. It will also help to inspire researchers on the study area. For the purpose of the research qualitative type of research is selected. Both primary and secondary data are used. Primary data is collected through interviews and the researcher’s observations and secondary data is collected from journal, Internet, published statistical resources, bulletins etc. 11 banks are chosen for the study including National Bank of Ethiopia. Managements lack of awareness, lack of industry best practices and standards in the country, lack of professional in the area are among the major challenges Ethiopian banks faces