11 research outputs found

    Proceedings of the Joint Automated Reasoning Workshop and Deduktionstreffen: As part of the Vienna Summer of Logic – IJCAR 23-24 July 2014

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    Preface For many years the British and the German automated reasoning communities have successfully run independent series of workshops for anybody working in the area of automated reasoning. Although open to the general public they addressed in the past primarily the British and the German communities, respectively. At the occasion of the Vienna Summer of Logic the two series have a joint event in Vienna as an IJCAR workshop. In the spirit of the two series there will be only informal proceedings with abstracts of the works presented. These are collected in this document. We have tried to maintain the informal open atmosphere of the two series and have welcomed in particular research students to present their work. We have solicited for all work related to automated reasoning and its applications with a particular interest in work-in-progress and the presentation of half-baked ideas. As in the previous years, we have aimed to bring together researchers from all areas of automated reasoning in order to foster links among researchers from various disciplines; among theoreticians, implementers and users alike, and among international communities, this year not just the British and German communities

    Conditionals and modularity in general logics

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    In this work in progress, we discuss independence and interpolation and related topics for classical, modal, and non-monotonic logics

    Pseudo-contractions as Gentle Repairs

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    Updating a knowledge base to remove an unwanted consequence is a challenging task. Some of the original sentences must be either deleted or weakened in such a way that the sentence to be removed is no longer entailed by the resulting set. On the other hand, it is desirable that the existing knowledge be preserved as much as possible, minimising the loss of information. Several approaches to this problem can be found in the literature. In particular, when the knowledge is represented by an ontology, two different families of frameworks have been developed in the literature in the past decades with numerous ideas in common but with little interaction between the communities: applications of AGM-like Belief Change and justification-based Ontology Repair. In this paper, we investigate the relationship between pseudo-contraction operations and gentle repairs. Both aim to avoid the complete deletion of sentences when replacing them with weaker versions is enough to prevent the entailment of the unwanted formula. We show the correspondence between concepts on both sides and investigate under which conditions they are equivalent. Furthermore, we propose a unified notation for the two approaches, which might contribute to the integration of the two areas

    Control room agents : an information-theoretic approach

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    In this thesis, a particular class of agent is singled out for examination. In order to provide a guiding metaphor, we speak of control room agents. Our focus is on rational decision- making by such agents, where the circumstances obtaining are such that rationality is bounded. Control room agents, whether human or non-human, need to reason and act in a changing environment with only limited information available to them. Determining the current state of the environment is a central concern for control room agents if they are to reason and act sensibly. A control room agent cannot plan its actions without having an internal representation (epistemic state) of its environment, and cannot make rational decisions unless this representation, to some level of accuracy, reflects the state of its environment. The focus of this thesis is on three aspects regarding the epistemic functioning of a control room agent: 1. How should the epistemic state of a control room agent be represented in order to facilitate logical analysis? 2. How should a control room agent change its epistemic state upon receiving new information? 3. How should a control room agent combine available information from different sources? In describing the class of control room agents as first-order intentional systems hav- ing both informational and motivational attitudes, an agent-oriented view is adopted. The central construct used in the information-theoretic approach, which is qualitative in nature, is the concept of a templated ordering. Representing the epistemic state of a control room agent by a (special form of) tem- plated ordering signals a departure from the many approaches in which only the beliefs of an agent are represented. Templated orderings allow for the representation of both knowledge and belief. A control room agent changes its epistemic state according to a proposed epistemic change algorithm, which allows the agent to select between two well-established forms of belief change operations, namely, belief revision and belief update. The combination of (possibly conflicting) information from different sources has re- ceived a lot of attention in recent years. Using templated orderings for the semantic representation of information, a new family of purely qualitative merging operations is developed.School of ComputingPh. D. (Computer Science

    Formal Description of Web Services for Expressive Matchmaking

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    Community-driven & Work-integrated Creation, Use and Evolution of Ontological Knowledge Structures

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    Semantic querying and search in distributed ontologies

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    We have observed in recent years a continuous growth in the quantity of RDF data accessible on the web. This evolution is primarily based on increasing data on the web by different sectors such as governments, life science researchers, or academic institutes. RDF data creation is mainly developed by replacing existing data resources with RDF, changing relational databases into RDF. These RDF data are usually called qualified linked data URIs and endpoints of SPARQL. Continuous development that we are experiencing in SPARQL endpoints requires accessing sets of distributed RDF data repositories is getting popularity. This research has offered an extensive analysis of accessing RDF data across distributed ontologies. The existing approaches lack a broad mix of RDF indexing and retrieving of distributed RDF data in one package. In addition, the efficiency of the current methods is not so dynamic and mainly depend on manual fixed strategies for accessing RDF data from a distributed environment. The literature review has acknowledged the need for a robust, reliable, dynamic, and comprehensive accessing mechanism for distributed RDF data using RDF indexing. This thesis presents the conceptual framework that demonstrates the SPARQL query execution process, which accesses the data within distributed RDF sets across a stored index. This thesis introduces the semantic algebra involved in the conversion of traditional SPARQL query language into different phases. The proposed framework elaborates the concepts included in selecting, projection, joins, specialisation and generalisation operators. These operators are usually in assistance during the process of processing and converting a SPARQL query. This thesis introduces the algorithms behind the proposed conceptual framework, which covert the main SPARQL query into sub-queries, sending each subquery to the required distributed repository to fetch the data and merging the sub queries results. 4 This research demonstrates the testing of the proposed framework using the unit and functional testing strategies. The author developed and utilised the Museum ontology to test and evaluate the developed system. It demonstrates all how the complete developed and processed system works. Different tests have been performed in this thesis, like the algebraic operator's test (e.g., select, join, outer join, generalisation, and specialisation operators test) and test the proposed algorithm. After comprehensive testing, it shows that all developed system units worked as expected, and no errors found during the testing of all phases of the tested framework. Finally, the thesis presents implemented framework's performance and accuracy by comparing it to other similar systems. Evaluation of the implemented system demonstrated that the proposed framework could handle distributed SPARQL queries very effectively. The author selected FedX, ANAPSID and ADERIS existing frameworks to compare with developed system and described the results in a graphical format to illustrate the performance and accuracy of all systems

    PSA 2020

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    These preprints were automatically compiled into a PDF from the collection of papers deposited in PhilSci-Archive in conjunction with the PSA 2020
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