Ontology Learning requires a deep specialization on Semantic Web, Knowledge Representation, Search Engines, Inductive Learning, Natural Language Processing, Information Storage, Extraction and Retrieval. Huge amount of domain specific, unstructured on-line data needs to be expressed in machine understandable and semantically searchable format. Currently users are often forced to search manually in the results returned by the keyword-based search services. They also want to use their native languages to express what they search. In this thesis we developed an ontology based question answering system that satisfies these needs by the research outputs of the areas stated above. The system allows users to enter a question about a restricted domain by means of natural language and returns exact answer of the questions. A set of questions are collected from the users in the domain. In addition to questions, their corresponding question templates were generated on the basis of the domain ontology. When the user asks a question and hits the search button, system chooses the suitable question template and builds a SPARQL query according to this template. System is also capable of answering questions required inference by using generic inference rules defined at a rule file. Our evaluation with ten users shows that the sytem is extremely simple to use without any training resulting in very good query performance.

Vast amount of radiology reports are produced in hospitals. Being in free text format and having errors due to rapid production, it continuously gets more complicated for radiologists and physicians to reach meaningful information. Though application of ontologies into bio-medical text mining has gained increasing interest in recent years, less work has been offered for ontology based retrieval tasks in Turkish language. In this work, an information extraction and retrieval system based on SNOMED-CT ontology has been proposed for Turkish radiology reports. Main purpose of this work is to utilize semantic relations in ontology to improve precision and recall rates of search results in domain. Practical problems encountered such as spelling errors, segmentation and tokenization of unstructured medical reports has also been addressed during the work.

The workshops on (constraint) logic programming (WLP) are the annual meeting of the Society of Logic Programming (GLP e.V.) and bring together researchers interested in logic programming, constraint programming, and related areas like databases, artificial intelligence and operations research. The 23rd WLP was held in Potsdam at September 15 – 16, 2009. The topics of the presentations of WLP2009 were grouped into the major areas: Databases, Answer Set Programming, Theory and Practice of Logic Programming as well as Constraints and Constraint Handling Rules.

The workshops on (constraint) logic programming (WLP) are the annual meeting of the Society of Logic Programming (GLP e.V.) and bring together researchers interested in logic programming, constraint programming, and related areas like databases, artificial intelligence and operations research. In this decade, previous workshops took place in Dresden (2008), Würzburg (2007), Vienna (2006), Ulm (2005), Potsdam (2004), Dresden (2002), Kiel (2001), and Würzburg (2000). Contributions to workshops deal with all theoretical, experimental, and application aspects of constraint programming (CP) and logic programming (LP), including foundations of constraint/ logic programming. Some of the special topics are constraint solving and optimization, extensions of functional logic programming, deductive databases, data mining, nonmonotonic reasoning, / interaction of CP/LP with other formalisms like agents, XML, JAVA, program analysis, program transformation, program verification, meta programming, parallelism and concurrency, answer set programming, implementation and software techniques (e.g., types, modularity, design patterns), applications (e.g., in production, environment, education, internet), constraint/logic programming for semantic web systems and applications, reasoning on the semantic web, data modelling for the web, semistructured data, and web query languages.

Social movement is the primary agency to enact social change, But, might not be achieved in a short time. After 1980s, the third sector in Taiwan has grown up quickly. Following different social movements, the sector has grown several organizational fields, such as environmental protection, the elderly welfare and the disable organizational fields. Reviewing the changes in organization fields above, they are enacted by social movement and organizations. The study focuses on ¡§non-profit disable organizational field¡¨ to discuss the change from ¡§handicapped¡¨ to ¡§disabled.¡¨ Furthermore, the new organizational form ¡§social enterprise¡¨ is emerging in this field recently. The study also explore the emerging process under the historical context in the field. Based on the institutional theory, The study focus on the contest of institutional logics in the field. Conducting the historical narrative approach, the study analysis archival material and interviews and divide the changing process in to 4 stages. The first stage (1949-1979) and second stage (1980-1990) were dominated by ¡§charity and relief¡¨ institutional logic. However, the social movements organized by the handicap were framing another new logic ¡§social model¡¨. In the third stage (1991-1998) the contest of two logics was much significant. Finally, the ¡§social model¡¨ logical won the contest and become the dominated logics in the forth stage (1999-2009). The study also revels that social enterprise is the product of new institutional logic. The study reveals ¡§social enterprise¡¨ is the by-product of institutional change in the non-profit disable organizational field. The study also discusses, following the institutional change, how the new actor introduce management model to change the disabled sheltered workshop becoming social enterprise.

Description Logics (DLs) are a family of logic-based knowledge representation (KR) formalisms designed to represent and reason about static conceptual knowledge in a semantically well-understood way. On the other hand, standard action formalisms are KR formalisms based on classical logic designed to model and reason about dynamic systems. The largest part of the present work is dedicated to integrating DLs with action formalisms, with the main goal of obtaining decidable action formalisms with an expressiveness significantly beyond propositional. To this end, we offer DL-tailored solutions to the frame and ramification problem. One of the main technical results is that standard reasoning problems about actions (executability and projection), as well as the plan existence problem are decidable if one restricts the logic for describing action pre- and post-conditions and the state of the world to decidable Description Logics. A smaller part of the work is related to decidable extensions of Description Logics with concrete datatypes, most importantly with those allowing to refer to the notions of space and time.

Description logics (DL) knowledge bases are often build by users with expertise in the application domain, but little expertise in logic. To support this kind of users when building their knowledge bases a number of extension methods have been proposed to provide the user with concept descriptions as a starting point for new concept definitions. The inference service central to several of these approaches is the computation of (least) common subsumers of concept descriptions. In case disjunction of concepts can be expressed in the DL under consideration, the least common subsumer (lcs) is just the disjunction of the input concepts. Such a trivial lcs is of little use as a starting point for a new concept definition to be edited by the user. To address this problem we propose two approaches to obtain "meaningful" common subsumers in the presence of disjunction tailored to two different methods to extend DL knowledge bases. More precisely, we devise computation methods for the approximation-based approach and the customization of DL knowledge bases, extend these methods to DLs with number restrictions and discuss their efficient implementation.

Description Logics (DLs) form a family of knowledge representation formalisms which can be used to represent and reason with conceptual knowledge about a domain of interest. The knowledge represented by DLs is mainly static. In many applications, the domain knowledge is dynamic. This observation motivates the research on how to update the knowledge when changes in the application domain take place. This thesis is dedicated to the study of updating knowledge, more precisely, assertional knowledge represented in DLs. We explore whether the updated knowledge can be expressed in several standard DLs and, if so, whether it is computable and what is its size.

The study of nonmonotonic logics is one mayor field of Artificial Intelligence (AI). The reason why such kind of formalisms are so attractive to model human reasoning is that they allow to withdraw former conclusion. At the end of the 1980s the novel idea of using argumentation to model nonmonotonic reasoning emerged in AI. Nowadays argumentation theory is a vibrant research area in AI, covering aspects of knowledge representation, multi-agent systems, and also philosophical questions. Phan Minh Dung’s abstract argumentation frameworks (AFs) play a dominant role in the field of argumentation. In AFs arguments and attacks between them are treated as primitives, i.e. the internal structure of arguments is not considered. The major focus is on resolving conflicts. To this end a variety of semantics have been defined, each of them specifying acceptable sets of arguments, so-called extensions, in a particular way. Although, Dung-style AFs are among the simplest argumentation systems one can think of, this approach is still powerful. It can be seen as a general theory capturing several nonmonotonic formalisms as well as a tool for solving well-known problems as the stable-marriage problem. This thesis is mainly concerned with the investigation of metalogical properties of Dung’s abstract theory. In particular, we provide cardinality, monotonicity and splitting results as well as characterization theorems for equivalence notions. The established results have theoretical and practical gains. On the one hand, they yield deeper theoretical insights into how this nonmonotonic theory works, and on the other the obtained results can be used to refine existing algorithms or even give rise to new computational procedures. A further main part is the study of problems regarding dynamic aspects of abstract argumentation. Most noteworthy we solve the so-called enforcing and the more general minimal change problem for a huge number of semantics.

This study examines university English-medium Instruction (EMI) reform implementation approaches from a comparative organizational perspective. Over the last decade, the number of master’s degree programs instructed exclusively in English in non-Anglophone Europe increased dramatically. Europe is an interesting case as it actively promotes multilingual learning; however, many European policies over the last twenty years accelerated the rise of monolingual EMI reforms, especially at the graduate-level. The purpose of this exploratory study is to contribute to our understanding of how widespread EMI reforms impact structures and behaviors at the organizational level in European universities in ways that respond to the organization’s embedded policy contexts. This research aims to advance our understandings of comparative EMI reforms and also, drawing on the concepts of neoinstitutional theory, develop our knowledge of how these processes might be theorized and expanded. I combine the theoretical frames of translation and institutional logics to analyze empirical case studies of the implementation of the EMI reform concept in three Northern European universities in leading EMI provider countries: the University of Oslo in Norway, the University of Göttingen in Germany, and Maastricht University in the Netherlands. The theoretical concept of institutional complexity is used to analyze the contending tensions universities confront when deciding the best way to design and implement EMI reforms. The three-axis comparative framework developed in this study represents a novel approach to examining variations in EMI reform implementation. Variations in organizational EMI implementation approaches (collegial, targeted, and market) are understood by analyzing comparatively how the three universities interpreted axial tensions between institutional logics for the best way to organize their EMI reform approaches: for academic or economic purposes; cooperative or competitive purposes; and local or global purposes. This comparative case study underscores the importance of examining a university’s embedded environment (both European and local levels) to understand university response to widespread EMI reform trends and highlights the significance of contextual dynamics to European EMI program development policy. The study concludes with policy recommendations and future directions.