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

Answering queries using views amounts to computing the answer to a query having information only on the extension of a set of precomputed queries (views). This problem is relevant in several fields, such as information integration, query optimization, and data warehousing, and has been studied recently in different settings. In this paper we address answering queries using views in a setting where intensional knowledge about the domain is represented using a very expressive Description Logic equipped with n-ary relations, and queries are nonrecursive datalog queries whose predicates are the concepts and relations that appear in the Description Logic knowledge base. We study the problem under different assumptions, namely, closed and open domain, and sound, complete, and exact information on view extensions. We show that under the closed domain assumption, in which the set of all objects in the knowledge base coincides with the set of objects stored in the views, answering queries using views is already intractable. We show also that under the open domain assumption the problem is decidable in double exponential time.

/pdf/answering-queries-using-views-over-description-logics-alj8m3gahu.pdf

Answering Queries Using Views over Description Logics Knowledge Bases

This chapter covers extensions of the basic Description Logics introduced in Chapter 2 by very expressive constructs that require advanced reasoning techniques. In particular, we study reasoning in Description Logics that include general inclusion axioms, inverse roles, number restrictions, reflexive-transitive closure of roles, fixpoint constructs for recursive definitions, and relations of arbitrary arity. The chapter will also address reasoning w.r.t. knowledge bases including both a TBox and an ABox, and discuss more general ways to treat objects. Since the logics considered in the chapter lack the finite model property, finite model reasoning is of interest and will also be discussed. Finally, we mention several extensions to Description Logics that lead to undecidability, confirming that the expressive Description Logics considered in this chapter are close to the boundary between decidability and undecidability.

/pdf/expressive-description-logics-58k8colb2w.pdf

Expressive description logics

In this paper, we study reasoning about actions and planning with incomplete information in a setting where the dynamic system is specified by adopting Linear Temporal Logic (ltl). Specifically, we study: (i) reasoning about action effects (i.e., projection, historical queries, etc.), in such a setting; (ii) when actions can be legally executed, assuming a non-prescriptive approach, where executing an action is possible in a given situation unless forbidden by the system specification; (iii) the problem of finding conformant plans for temporally extended goals that consist of arbitrary ltl formulas, thus allowing for expressing sophisticated dynamic requirements. For each of these problems we establish techniques and characterize the computational complexity. For the last two problems we make use of a second-order variant of ltl.

/pdf/reasoning-about-actions-and-planning-in-ltl-action-theories-2r4ylh6rg0.pdf

Reasoning about actions and planning in LTL action theories

The promise of Web Service Computing is to use Web services as fundamental elements for realizing distributed applications/solutions. When no available service satisfies a desired specification, one might check whether (parts of) available services can be composed and orchestrated in order to realize the specification. The problem of automatic composition becomes especially interesting in the presence of conversational services. Among the various frameworks proposed in the literature, here we concentrate on the so called “Roman Model”, where: (i) each service is formally specified as a transition system that captures its possible conversations with a generic client; (ii) the desired specification is a target service, described itself as a transition system; (iii) the aim is to synthesize an orchestrator realizing the target service by exploiting execution fragments of available services. The Roman Model well exemplifies what can be achieved by composing conversational services and, also, uncovers relationships with automated synthesis of reactive processes in Verification and AI Planning.

/pdf/automatic-service-composition-and-synthesis-the-roman-model-48iu486p84.pdf

Automatic Service Composition and Synthesis: the Roman Model.

There are basically two approaches for designing a data integration system. In the global-as-view (GAV) approach, one maps the concepts in the global schema to views over the sources, whereas in the local-as-view (LAV) approach, one maps the sources into views over the global schema. The goal of this paper is to relate the two approaches with respect to their expressive power. The analysis is carried out in a relational database setting, where both the queries on the global schema, and the views in the mapping are conjunctive queries. We introduce the notion of query-preserving transformation, and query-reducibility between data integration systems, and we show that, when no integrity constraints are allowed in global schema, the LAV and the GAV approaches are incomparable. We then consider the addition of integrity constraints in the global schema, and present techniques for query-preserving transformations in both directions. Finally, we show that our results imply that we can always transform any system following the GLAV approach (a generalization of both LAV and GAV) into a query-preserving GAV system.

Giuseppe De Giacomo

Papers

Answering Queries Using Views over Description Logics Knowledge Bases

Expressive description logics

Reasoning about actions and planning in LTL action theories

Automatic Service Composition and Synthesis: the Roman Model.

On the expressive power of data integration systems