다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

An Introduction to MultiAgent Systems.

https://www.cs.ox.ac.uk/people/bernardo.cuencagrau/publications/PelletDemo.pdf

Pellet: A practical OWL-DL reasoner

Data integration is the problem of combining data residing at different sources, and providing the user with a unified view of these data. The problem of designing data integration systems is important in current real world applications, and is characterized by a number of issues that are interesting from a theoretical point of view. This document presents on overview of the material to be presented in a tutorial on data integration. The tutorial is focused on some of the theoretical issues that are relevant for data integration. Special attention will be devoted to the following aspects: modeling a data integration application, processing queries in data integration, dealing with inconsistent data sources, and reasoning on queries.

/pdf/data-integration-a-theoretical-perspective-58aesjvhuk.pdf

Data integration: a theoretical perspective

In the last years, the investigation on Description Logics (DLs) has been driven by the goal of applying them in several areas, such as, software engineering, information systems, databases, information integration, and intelligent access to the web. The modeling requirements arising in the above areas have stimulated the need for very rich languages, including fixpoint constructs to represent recursive structures. We study a DL comprising the most general form of fixpoint constructs on concepts, all classical concept forming constructs, plus inverse roles, n-ary relations, qualified number restrictions, and inclusion assertions. We establish the EXPTIME decidability of such logic by presenting a decision procedure based on a reduction to nonemptiness of alternating automata on infinite trees. We observe that this is the first decidability result for a logic combining inverse roles, number restrictions, and general fixpoints.

/pdf/reasoning-in-expressive-description-logics-with-fixpoints-4rtkbk2wah.pdf

Reasoning in expressive description logics with fixpoints based on automata on infinite trees

We study an automata-theoretic approach to planning for temporally extended goals. Specifically, we devise techniques based on nonemptiness of Buchi automata on infinite words, to synthesize sequential and conditional plans in a generalized setting in which we have that: goals are general temporal properties of desired execution; dynamic systems are represented by finite transition systems; incomplete information on the initial situation is allowed; and states are only partially observable. We prove that the techniques proposed are optimal wrt the worst case complexity of the problem. Thanks to the scalability of the nonemptiness algorithms, the techniques presented here promise to be applicable to fairly large systems, notwithstanding the intrinsic complexity of the problem.

/pdf/automata-theoretic-approach-to-planning-for-temporally-39fqocx9ui.pdf

Automata-Theoretic Approach to Planning for Temporally Extended Goals

Recent proposals to improve the quality of interaction with the World Wide Web suggest considering the Web as a huge semistructured database, so that retrieving information can be supported by the task of database querying. Under this view, it is important to represent the form of both the network, and the documents placed in the nodes of the network. However, the current proposals do not pay su‐cient attention to represent document structures and reasoning about them. In this paper, we address these problems by providing a framework where Document Type Deflnitions (DTDs) expressed in the eXtensible Markup Language (XML) are formalized in an expressive Description Logic equipped with sound and complete inference algorithms. We provide methods for verifying conformance of a document to a DTD in polynomial time, and structural equivalence of DTDs in worst case deterministic exponential time, improving known algorithms for this problem which were double exponential. We also deal with parametric versions of conformance and structural equivalence, and investigate other forms of reasoning on DTDs. Finally, we show how to take advantage of the reasoning capabilities of our formalism in order to perform several optimization steps in answering queries posed to a document base.

/pdf/representing-and-reasoning-on-xml-documents-a-description-2kse7p2npa.pdf

Representing and reasoning on XML documents: a description logic approach

DLR is an expressive Description Logic (DL) with n-ary relations, particularly suited for modeling database schemas. Although DLR has constituted one of the crucial steps for applying DL technology to data management, there is one important aspect of database schemas that DLs, including DLR, do not capture yet, namely the notion of identification constraints and functional dependencies. In this paper we introduce a DL which extends DLR and fully captures the semantics of such constraints, and we address the problem of reasoning in such a logic. We show that, verifying knowledge base satisfiability and logical implication in the presence of identification constraints and nonunary functional dependencies can be done in EXPTIME, thus with the same worst-case computational complexity as for plain DLR. We also show that adding just unary functional dependencies to DLR leads to undecidability.

/pdf/identification-constraints-and-functional-dependencies-in-2gum761p8s.pdf

Identification constraints and functional dependencies in description logics

One of the basic problems in the development of techniques for the semantic web is the integration of ontologies. In this paper we deal with a situation where we have various local ontologies, developed independently from each other, and we are required to build an integrated, global ontology as a mean for extracting information from the local ones. In this context, the problem of how to specify the mapping between the global ontology and the local ontologies is a fundamental one, and its solution is essential for establishing an ontology of integration. Description Logics (DLs) are an ideal candidate to formalize ontologies, due to their ability to express complex relationships between concepts. We argue, however, that, for capturing the mapping between different ontologies, the direct use of a DL, even a very expressive one, is not sufficient, and it is necessary to resort to more flexible mechanisms based on the notion of query. Also, we elaborate on the observation that, in the semantic web, the case of mutually inconsistent local ontologies will be very common, and we present the basic ideas in order to extend the integration framework with suitable nonmonotonic features for dealing with this case.

/pdf/ontology-of-integration-and-integration-of-ontologies-19makrhwsd.pdf

Giuseppe De Giacomo

Papers

Reasoning in expressive description logics with fixpoints based on automata on infinite trees

Automata-Theoretic Approach to Planning for Temporally Extended Goals

Representing and reasoning on XML documents: a description logic approach

Identification constraints and functional dependencies in description logics

Ontology of Integration and Integration of Ontologies.