scholarly journals Scalable Dynamic Multi-Agent Practical Byzantine Fault-Tolerant Consensus in Permissioned Blockchain

2018 ◽  
Vol 8 (10) ◽  
pp. 1919 ◽  
Author(s):  
Libo Feng ◽  
Hui Zhang ◽  
Yong Chen ◽  
Liqi Lou
Keyword(s):  
Large Scale ◽  
Fault Tolerant ◽  
Autonomous Systems ◽  
Communication Costs ◽  
Financial Applications ◽  
Byzantine Fault ◽  
Wide Range ◽  
Multi Agent ◽  
Simulation Results ◽  
The Internet Of Things

The permissioned blockchain system has recently become popular in a wide range of scenarios, such as artificial intelligence, financial applications and the Internet of things, due to its dominance in terms of distribution, decentralization, reliability and security. However, the Practical Byzantine Fault-Tolerant (PBFT) algorithm, which is currently adopted in such systems, sparks communication bottlenecks when the number of consensus nodes increases sharply, which seriously hinders large-scale applications. In this paper, we propose a scalable dynamic multi-agent hierarchical PBFT algorithm (SDMA-PBFT), which reduces the communication costs from O(n2) to O( n × k × log k n ). Specifically, SDMA-PBFT forms multiple autonomous systems at each agent node in which message multicasting can be efficiently carried out and the internal voting results can be effectively collected. Therefore, the design of these agent nodes facilitates the in-and-out operations of consensus nodes in the blockchain system. Simulation results show that our proposed algorithm substantially outperforms the PBFT algorithm in terms of latency. Hence, it can be applied to the permissioned blockchain system effectively and efficiently.

scholarly journals Design and Evaluation of Large-Scale IoT-Enabled Healthcare Architecture

2021 ◽  
Vol 11 (8) ◽  
pp. 3623
Author(s):  
Omar Said ◽  
Amr Tolba
Keyword(s):  
Packet Loss ◽  
Large Scale ◽  
Performance Metrics ◽  
Medical System ◽  
Healthcare Data ◽  
High Altitude Platforms ◽  
Wide Range ◽  
Simulation Results ◽  
Healthcare Architecture ◽  
The Internet Of Things

Employment of the Internet of Things (IoT) technology in the healthcare field can contribute to recruiting heterogeneous medical devices and creating smart cooperation between them. This cooperation leads to an increase in the efficiency of the entire medical system, thus accelerating the diagnosis and curing of patients, in general, and rescuing critical cases in particular. In this paper, a large-scale IoT-enabled healthcare architecture is proposed. To achieve a wide range of communication between healthcare devices, not only are Internet coverage tools utilized but also satellites and high-altitude platforms (HAPs). In addition, the clustering idea is applied in the proposed architecture to facilitate its management. Moreover, healthcare data are prioritized into several levels of importance. Finally, NS3 is used to measure the performance of the proposed IoT-enabled healthcare architecture. The performance metrics are delay, energy consumption, packet loss, coverage tool usage, throughput, percentage of served users, and percentage of each exchanged data type. The simulation results demonstrate that the proposed IoT-enabled healthcare architecture outperforms the traditional healthcare architecture.

scholarly journals Enhancing the Reliability of Cellular Internet of Things through Agreement

2020 ◽  
Vol 10 (21) ◽  
pp. 7699
Author(s):  
Shin-Hung Pan ◽  
Shu-Ching Wang
Keyword(s):  
Internet Of Things ◽  
Large Scale ◽  
Fault Tolerant ◽  
Smart Cities ◽  
Smart Devices ◽  
The Internet ◽  
Smart Transportation ◽  
Fifth Generation ◽  
Smart Healthcare ◽  
Wide Range

Because the Internet of Things (IoT) can provide a global service network through various smart devices, the IoT has been widely used in smart transportation, smart cities, smart healthcare, and factory automation through the Internet connection. With the large-scale establishment and 5G (fifth generation) wireless networks, the cellular Internet of Things (CIoT) will continue to be developed and applied to a wide range of applications. In order to provide a reliable application of CIoT, a safe and reliable network topology MECIoT is proposed in this study. To improve the reliability and fault-tolerant capability of the network proposed, the problem of reaching agreement should be revisited. Therefore, the applications in the system can still be performed correctly even if some processing units (PUs) in the system have failed. In this study, a new protocol is proposed to allow all normal PUs in MECIoT to reach an agreement with the minimum amount of data exchanges required and the maximum number of failed PUs allowed in MECIoT. In the end, the optimality of the protocol has been proven by mathematical method.

BAMcast - byzantine fault-tolerant consensus service for Atomic Multicast in large-scale networks

2013 ◽  
Author(s):  
Marcelo Ribeiro Xavier Silva ◽  
Lau Cheuk Lung ◽  
Leandro Quibem Magnabosco ◽  
Luciana de Oliveira Rech
Keyword(s):  
Large Scale ◽  
Fault Tolerant ◽  
Byzantine Fault ◽  
Large Scale Networks

scholarly journals Byzantine fault-tolerant routing for large-scale wireless sensor networks based on fast ECDSA

2015 ◽  
Vol 20 (6) ◽  
pp. 627-633 ◽  
Author(s):  
Jiawei Xu ◽  
Keda Wang ◽  
Chao Wang ◽  
Feng Hu ◽  
Zhenhua Zhang ◽  
...  
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Large Scale ◽  
Fault Tolerant ◽  
Wireless Sensor ◽  
Byzantine Fault

scholarly journals Detection of Node Failure in Wireless Image Sensor Networks

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Arunanshu Mahapatro ◽  
Pabitra Mohan Khilar
Keyword(s):  
Fault Diagnosis ◽  
Fault Tolerant ◽  
Image Sensor ◽  
High Accuracy ◽  
Sensor Nodes ◽  
Message Complexity ◽  
Wide Range ◽  
Node Architecture ◽  
Diagnosis Model ◽  
Simulation Results

A sequenced process of fault detection followed by dissemination of decision made at each node characterizes the sustained operations of a fault-tolerant wireless image sensor network (WISN). This paper presents a distributed self-fault diagnosis model for WISN where fault diagnosis is achieved by disseminating decision made at each node. Architecture of fault-tolerant wireless image sensor nodes is presented. Simulation results show that sensor nodes with hard and soft faults are identified with high accuracy for a wide range of fault rate. Both time and message complexity of the proposed algorithm are for an -node WISN.

A Dispatcher for a Multi-Agent Control System of an Autonomous Underwater Vehicle: Structure, Algorithms, and Simulation Results

2020 ◽  
Vol 28 (3) ◽  
pp. 109-121
Author(s):  
V.S. Bykova ◽  
◽  
L.A. Martynova ◽  
A.I. Mashoshin ◽  
I.V. Pashkevich ◽  
...  
Keyword(s):  
Control System ◽  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Wide Range ◽  
Vehicle Structure ◽  
Multi Agent ◽  
Agent Control ◽  
Simulation Results

Algorithms for a dispatcher of a multi-agent control system for an autonomous underwater vehicle (AUV) are described. The algorithms are designed on a modular basis, which provides for the control of a wide range of tasks assigned to the AUV, and, in addition, makes the implementation of each algorithm simple.

scholarly journals Moist Convection and the Thermal Stratification of the Extratropical Troposphere

2008 ◽  
Vol 65 (11) ◽  
pp. 3571-3583 ◽  
Author(s):  
Tapio Schneider ◽  
Paul A. O’Gorman
Keyword(s):  
Latent Heat ◽  
Thermal Stratification ◽  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Lapse Rate ◽  
Moist Convection ◽  
Wide Range ◽  
Simulation Results ◽  
Warm Climates

Abstract Simulations with an aquaplanet general circulation model show that sensible and latent heat transport by large-scale eddies influences the extratropical thermal stratification over a wide range of climates, even in relatively warm climates with small meridional surface temperature gradients. Variations of the lapse rate toward which the parameterized moist convection in the model relaxes atmospheric temperature profiles demonstrate that the convective lapse rate only marginally affects the extratropical thermal stratification in Earth-like and colder climates. In warmer climates, the convective lapse rate does affect the extratropical thermal stratification, but the effect is still smaller than would be expected if moist convection alone controlled the thermal stratification. A theory for how large-scale eddies modify the thermal stratification of dry atmospheres is consistent with the simulation results for colder climates. For warmer and moister climates, however, theories and heuristics that have been proposed to account for the extratropical thermal stratification are not consistent with the simulation results. Theories for the extratropical thermal stratification will generally have to take transport of sensible and latent heat by large-scale eddies into account, but moist convection may only need to be taken into account regionally and in sufficiently warm climates.

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