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

We consider the following elusive question which has generated a lot of ad hoc research: In synthesis/planning, which constraints on traces are environment assumptions? We propose to view assumptions as sets of strategies and not, as is typical, as sets of traces, even for assumptions expressed as linear-temporal formulas on traces. This shift in perspective allows us to give a principled and conceptually clear answer to this question, as well as to reuse results and techniques for synthesis in order to solve synthesis under assumptions. Context. Reasoning about actions and planning concerns the representation of a dynamic system (Reiter 2001). Such a representation corresponds to knowledge that the agent has of the environment. In devising plans, the agent takes advantage of such a representation of the world. In other words, the agent assumes that the environment works in a certain way, and exploits such an assumption in devising its plans. A question immediately comes to mind: What is an environment assumption? Obviously the planning domain itself (including the initial state) with its preconditions and effects is an environment assumption. That is, as long as the agent sticks to its preconditions, the environment acts as described by the domain. So, the agent can exploit the effect of its actions in order to reach a certain goal (state of affairs). It is also common to assume the domain is fair, cf. (D’Ippolito, Rodrı́guez, and Sardiña 2018), or more generally that the environment’s behavior is restricted by trajectory constraints, often expressed in LTL, cf. (De Giacomo et al. 2016; Bonet et al. 2017). But, is any kind of formula on the fluents and actions of the domain a possible trajectory constraint for the environment? The answer is obviously “no” — indeed, consider a formula expressing that eventually a certain possible action must actually be performed — the agent may decide not to do it. But then we ask: Which linear-time specifications are environment as-

Synthesis under Assumptions.

In this paper, we study reasoning about actions following a model checking approach in contrast to the usual validity checking one. Specifically, we model a dynamic system as a transition graph which represents all the possible system evolutions in terms of state changes caused by actions. Such a transition graph is defined by means of a suitable process algebra associated with an explicit global store. To reason about system properties we introduce an extension of modal µ-calculus. This setting, although directly applicable only when complete information on the system is available, has several interesting features for reasoning about actions. On one hand, it inherits from the vast literature on process algebras tools for dealing with complex systems, treating suitably important aspects like parallelism, communications, interruptions, coordinations among agents. On the other hand, reasoning by model checking is typically much easier than more general logical services such as validity checking.

/pdf/reasoning-about-nondeterministic-and-concurrent-actions-a-52jgmtztgs.pdf

Reasoning about nondeterministic and concurrent actions: a process algebra approach

Decentralized data management has been addressed during the years by means of several technical solutions, ranging from distributed DBMSs, to mediatorbased data integration systems. Recently, such an issue has been investigated in the context of Peer-to-Peer (P2P) architectures. In this chapter we focus on P2P data integration systems, which are characterized by various autonomous peers, each peer being essentially an autonomous information system that holds data and is linked to other peers by means of P2P mappings. P2P data integration does not rely on the notion of global schema, as in traditional mediator-based data integration. Rather, it computes answers to users’ queries, posed to any peer of the system, on the basis of both local data and the P2P mappings, thus overcoming the main drawbacks of centralized mediator-based data integration systems and providing the foundations of effective data management in virtual organizations. In this chapter we first survey the most significant approaches proposed in the literature for both mediator-based data integration and P2P data management. Then, we focus on advanced schema-based P2P systems for which the aim is semantic integration of data, and analyze the commonly adopted approach of interpreting such systems using a first-order semantics. We show some weaknesses of this approach, and compare it with an alternative approach, based on multi-modal epistemic semantics, which reflects the idea that each peer is conceived as a rational agent that exchanges knowledge/belief with other peers. We consider several central properties of P2P data integration systems: modularity, generality, and decidability. We argue that the approach based on epistemic logic is superior with respect to all the

/pdf/data-management-in-peer-to-peer-data-integration-systems-5c09svz9dq.pdf

Data management in peer-to-peer data integration systems

We investigate an extension of Description Logics with higher-order capabilities, based on Henkin-style semantics. Our study starts from the observation that the various possibilities of adding higher-order constructs to a DL form a spectrum of increasing expressive power, including domain metamodeling, i.e., using concepts and roles as predicate arguments, and full metamodeling, providing the ability of using the language constructors and operators as predicate arguments, in the style of RDF. We argue that higher-order features of the former type are sufficiently rich and powerful for the modeling requirements arising in many relevant situations, and therefore we carry out an investigation of the computational complexity of reasoning in DLs extended with such features. In particular, we show that adding domain metamodeling capabilities to expressive DLs has no impact on the complexity of the various reasoning tasks.

/pdf/on-higher-order-description-logics-rc00ngihd9.pdf

On higher-order description logics

The emerging trend in process management and in service oriented applications is to enable the composition of new distributed processes on the basis of user requests, through (parts of) available (and often embedded in the environment) services to be composed and orchestrated in order to satisfy such requests. Here, we consider a user process as specified in terms of repeated goals that the user may choose to get fulfilled, organized in a kind of routine. Available services are suitably composed and orchestrated in order to realize such a process. In particular we focus on smart homes, in which available services are those ones offered by sensor and actuator devices deployed in the home, and the target user process is directly and continuously controlled by the inhabitants, through actual goal choices. We provide a solver that synthesizes the orchestrator for the requested process and we show its practical applicability in a real smart home use case.

https://www.dis.uniroma1.it/~degiacom/papers/2012/CoopIS12.pdf

Giuseppe De Giacomo

Papers

Synthesis under Assumptions.

Reasoning about nondeterministic and concurrent actions: a process algebra approach

Data management in peer-to-peer data integration systems

On higher-order description logics

Goal-Based Composition of Stateful Services for Smart Homes