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

Digital Twin technology is an emerging concept that has become the centre of attention for industry and, in more recent years, academia. The advancements in industry 4.0 concepts have facilitated its growth, particularly in the manufacturing industry. The Digital Twin is defined extensively but is best described as the effortless integration of data between a physical and virtual machine in either direction. The challenges, applications, and enabling technologies for Artificial Intelligence, Internet of Things (IoT) and Digital Twins are presented. A review of publications relating to Digital Twins is performed, producing a categorical review of recent papers. The review has categorised them by research areas: manufacturing, healthcare and smart cities, discussing a range of papers that reflect these areas and the current state of research. The paper provides an assessment of the enabling technologies, challenges and open research for Digital Twins.

Digital Twin: Enabling Technologies, Challenges and Open Research

Digital twin can be defined as a virtual representation of a physical asset enabled through data and simulators for real-time prediction, optimization, monitoring, controlling, and improved decision making. Recent advances in computational pipelines, multiphysics solvers, artificial intelligence, big data cybernetics, data processing and management tools bring the promise of digital twins and their impact on society closer to reality. Digital twinning is now an important and emerging trend in many applications. Also referred to as a computational megamodel, device shadow, mirrored system, avatar or a synchronized virtual prototype, there can be no doubt that a digital twin plays a transformative role not only in how we design and operate cyber-physical intelligent systems, but also in how we advance the modularity of multi-disciplinary systems to tackle fundamental barriers not addressed by the current, evolutionary modeling practices. In this work, we review the recent status of methodologies and techniques related to the construction of digital twins mostly from a modeling perspective. Our aim is to provide a detailed coverage of the current challenges and enabling technologies along with recommendations and reflections for various stakeholders.

/pdf/digital-twin-values-challenges-and-enablers-from-a-modeling-3hpoelaogn.pdf

Digital Twin: Values, Challenges and Enablers From a Modeling Perspective

Internet of Things (IoT) is reshaping the incumbent industry to smart industry featured with data-driven decision-making. However, intrinsic features of IoT result in a number of challenges, such as decentralization, poor interoperability, privacy, and security vulnerabilities. Blockchain technology brings the opportunities in addressing the challenges of IoT. In this paper, we investigate the integration of blockchain technology with IoT. We name such synthesis of blockchain and IoT as blockchain of things (BCoT). This paper presents an in-depth survey of BCoT and discusses the insights of this new paradigm. In particular, we first briefly introduce IoT and discuss the challenges of IoT. Then, we give an overview of blockchain technology. We next concentrate on introducing the convergence of blockchain and IoT and presenting the proposal of BCoT architecture. We further discuss the issues about using blockchain for fifth generation beyond in IoT as well as industrial applications of BCoT. Finally, we outline the open research directions in this promising area.

Blockchain for Internet of Things: A Survey

Recently, artificial intelligence (AI) and blockchain have become two of the most trending and disruptive technologies. Blockchain technology has the ability to automate payment in cryptocurrency and to provide access to a shared ledger of data, transactions, and logs in a decentralized, secure, and trusted manner. Also with smart contracts, blockchain has the ability to govern interactions among participants with no intermediary or a trusted third party. AI, on the other hand, offers intelligence and decision-making capabilities for machines similar to humans. In this paper, we present a detailed survey on blockchain applications for AI. We review the literature, tabulate, and summarize the emerging blockchain applications, platforms, and protocols specifically targeting AI area. We also identify and discuss open research challenges of utilizing blockchain technologies for AI.

/pdf/blockchain-for-ai-review-and-open-research-challenges-33tn3ujawh.pdf

Blockchain for AI: Review and Open Research Challenges

This work describes a generic peer to peer (P2P) simulator for service oriented networks. The tool has been designed to test different algorithms, the version presented here includes the implementation of a collaborative file sharing service, designed to simulate different user behaviours with the goal of analyzing the impact of malicious users on this kind of service. The file sharing service proposal includes a coalition formation algorithm and a reputation mechanism to ensure service equity, based on game theory.

/pdf/file-sharing-service-over-a-generic-p2p-simulator-2wsqssx9sh.pdf

File Sharing Service over a Generic P2P Simulator

P2P systems suffer from free-loaders, peers that consume many more resources or contents (bandwidth) than they contribute. One of the reasons for this is that the mechanisms used for downloading and sharing in the P2P systems, do no take selfish behavior of the peers into account at the design stage. Therefore, it is important to find mechanisms that provide incentives and encourage cooperative behavior among the peers. One possible solution could be to use an economic framework that provides them with incentives. We propose the application of a coalition formation scheme based on game theory to P2P file sharing systems. The main idea for the coalition formation scheme is based on the fact that peers that contribute more get a better quality of service. A peer that participates in a coalition lends ”bandwidth” to other peers of the coalition, in exchange for utility and consequently far greater download bandwidth. Simulation results have shown the effectiveness of the mechanism in stopping the free-riding peers and encouraging cooperation, increasing the performance of a P2P network and obtaining an improvement in time download performance.

A coalition based incentive mechanism for p2p content distribution systems

Nowadays, Peer-to-Peer is responsible for more than 60% of Internet traffic. These protocols have proved to save bandwidth and computing resources in content distribution system. But, problems related to user behaviour, such as free riding, still persist, and users must be motivated to share content. In previous work, we have designed and simulated a coalition and incentive theoretical mechanism for content distribution that aims to fight against problems in user behaviour. In this pa- per, we present a real implementation of it. Since devel- oping a peer-to-peer application from scratch is a labori- ous and error prone task, we use SMEPP, a middleware that aims to ease the development of secure distributed application, to implement it.

/pdf/coalitions-and-incentives-for-content-distribution-over-a-u5m79hkygh.pdf

Coalitions and Incentives for Content Distribution over a Secure Peer-to-Peer Middleware

In the Internet of Things (IoT) a worldwide network of sensors and actuators transmit data and actuate over the Internet. Nevertheless, the deployment of sensors and actuators usually requires tools to program and configure them before they can work, and not everyone has such access. Current smartphones are provided with a large set of sensors and actuators that can be incorporated in the IoT. With the aim of achieving seamless integration, this paper presents SocICoAP, a system that enables the sharing of sensors and actuators present in smartphones and installing custom ones at run-time in microcontrollers. In this way smartphones are integrated into the IoT, not only a sensor providing data from its built-in sensors but also as a gateway for nearby deployed sensors. Furthermore, the sensor data can also be globally shared and analysed through a cloud computing integration.

SocICoAP: Social Interaction with Supplementary Sensors and Actuators through CoAP in Smartphones

The natural selfish behavior of P2P system users, has given rise to the appearance of freeriding. These users download but don’t contribute to the system, leading to a degradation of the system, and the user experiences. It becomes mandatory to find proper mechanisms to incentive cooperation among users in these systems. In this paper we provide an incentive based coalitions to improve the system welfare and users experiences. A peer that participates in a coalition lends “bandwidth” to other peers of the coalition, in exchange for utility and consequently a far better experience. Taking concepts from game theory we provide a solid ground upon which we build our mechanism . Simulated experiments support the approach, showing how encouraging participation stops freeriding and therefore improve the system performance and the user experience.

Ana Reyna

Papers

File Sharing Service over a Generic P2P Simulator

A coalition based incentive mechanism for p2p content distribution systems

Coalitions and Incentives for Content Distribution over a Secure Peer-to-Peer Middleware

SocICoAP: Social Interaction with Supplementary Sensors and Actuators through CoAP in Smartphones

Improving File Sharing Experience with Incentive Based Coalitions