1,720,972 research outputs found
Off-chain trading for micro grid systems
Full text linkAs micro grids and blockchain gained the interest and attention of both academia and the industry, the interaction between the two technologies seems inevitable. However, there are challenges to overcome in order to actually realize the integration between micro grids and blockchains. In this article, we review the solutions proposed to enhance micro grids with blockchains. We discuss the scalability challenges and the opportunities derived from the off-chaining computing techniques. In this context, we draft a design to implement a micro grid-based peer-to-peer local energy market, powered by an off-chain computing protocol called DIVERSITY. DIVERSITY aims to shift the computational burden from a main blockchain to an intermediate layer of nodes, aggregating data and executing smart contracts off-chain. We simulate different data logging approaches, and it is found that DIVERSITY allows an actual saving on fees and power consumption derived from using a public blockchain platform, such as Ethereum, in order to assure a truly decentralized renewable energy distribution at a lower cost
Robot Based Computing System: An Educational Experience
Full text linkRobot based computing systems have been widely investigated in the last years. One of the main issues is to solve global tasks by means of local and simple computations. Robots might be cooperative or competitive, still the algorithm designer has to detect a way to accomplish the desired task. In this paper, we propose a platform made up of small and self-propelled robots with very limited capabilities in terms of computing resources, storage and sensing. In particular, we consider cheap robots moving within a confined area. The area is suitably coloured so as to be able for a robot endowed with a light sensor to reasonably detect its position. Moreover, robots can communicate with each other by exchanging short messages. Based only on those weak capabilities, we show how it is possible to realise interesting basic tasks. Apart for the relevance in educational contexts, our platform also represents an interesting case study for the main question posed in the literature about the minimal settings under which interesting tasks can be distributively solved
Share: A Design Pattern for Dynamic Composition of IoT Services
No full textThe Internet-of-Things (IoT) is one of the modern technological revolutions that enables communication amongst a plethora of different devices. To date 30 billion devices are connected to the internet more than 75 billion devices are foreseen to be connected worldwide by 2025, a five fold increase in ten years. Devices can have different brands and developers and can be designed to function on a proprietary ecosystem, with separate applications, gateways and tools to support them. This fragmentation can be disastrous in certain industries, such as the medical ones, and limit integration between different systems. In this paper, we envision a solution to overcome this interaction problems. We propose Share a novel programming standard through a design pattern. This allows on the fly service composition of resource constrained IoT devices. To this ending, IoT devices exchange integration codes which specify the data format and the interaction protocol. The design by contract scheme (DCS) is used to make sure that the matching services verify the constraints dictated by the composition. Unlike other on the fly approaches, Share can run on very small and resource constrained devices. Share has been implemented by using LUA programming language and has been validated on the ESP30 embedded device
Applying REECHD to non-uniformly distributed heterogeneous devices
No full textHeterogeneous Wireless Sensor Networks (WSNs) are essential to implement the IoT
vision. They are a virtual skin that allows the gathering of environmental data. This can be
used to enhance human life and build innovative applications such as smart environments,
advance health care systems and smart cities. WSNs are composed of nodes that can have
dierent initial energy, dierent node transmission rate and dierent hardware. Energy
eciency is one of the most important challenges when building WSNs since nodes are
battery powered. Clustering is an extensively used approach to enhance the heterogeneous
WSN lifetime. Clustering partitions the WSN nodes into a set of clusters. Each cluster
contains a cluster head (CH) that collects data from its member nodes and forwards them
to a centralised Base Station (BS). Although a plethora of dierent clustering approaches
have been proposed CH selection is usually based on the node residual energy. Some
approaches can take into account the node transmission rate but only for cluster formation.
Rotating Energy Ecient Clustering for Heterogeneous Devices (REECHD) is our novel
clustering algorithm that considers both node residual energy and node transmission rate
for cluster head election. REECHD also proposes the introduction of the intra-trac
rate limit (ITRL). This limits the amount of intra-trac data that a CH can receive.
ITRL can improve energy eciency. In this work we apply REECHD to a WSN where
devices are not uniformly distributed. More precisely, we consider WSNs where some
subareas generate a higher volume of trac. We show how the use of ITRL improves
energy eciency by adaptively generating a dierent amount of clusters in dierent WSN
subareas. REECHD outperforms the state of art clustering protocols of 220% when rst
node die lifetime measure is considered. Our results show that REECHD enhances on
average the network lifespan when compared to the state of art protocols
Off-Chain Execution of IoT Smart Contracts
No full textModern blockchains allow the definition of smart contracts (SCs). An SC is a computer protocol designed to digitally ease, verify, or enforce the terms of agreement between users. SCs execution can require high fees when lots of computation is required or a high volume of data is stored. This is usually the case of Internet-of-Things (IoT) systems where a large amount of devices can produce a high volume of data. Off-chain contract execution is a viable solution to decrease the blockchain fees. Users can agree on an on-chain SC which is stored in the main chain. Computation can then be moved securely outside the chain to reduce fees. In this paper we propose DIVERSITY a novel approach that allows off-chain execution of SCs. DIVERSITY provides a novel model for defining on-chain contracts that can be securely executed by using a novel off-chain protocol. We have validate our approach on a novel IoT case study where fees have been greatly reduced
Blockchain and IoT Integration for Society 5.0
No full textThe integration of Blockchain and Internet of Things (IoT) will have many implications in the Society 5.0. Blockchain technology has the potential to deal with issues that are related to data ownership, data integrity and data market monopolies. Public blockchains support the implementation of the data democratisation vision where everybody has access to data and there are no gatekeepers that make use of isolated data silos. Smart contracts can be used to provide contract transparency and allow citizens to manage their own data and the deriving economic value. This paper describes a novel blockchain-based security protocol that has been applied to a bicycle rental case study. This has been designed and implemented with the Society 5.0 vision in mind. Users store their own rental data by using a public blockchain. This eliminates the need of a centralised authority, provides data immutability and allows users to agree on transparent smart contract to manage their insurance, their payments and their own rental data. The smart lock protocol has been implemented in a real industrial product that uses the Ethereum public blockchain
Energy Saving and Collision-Free Motion Planning for Oblivious Robots
No full textIn distributed computing, many tasks have been studied involving mobile entities - also called robots - with weak capabilities. A well-known scenario is that in which robots operate in Look-Compute-Move (LCM) cycles. During each cycle, a robot acquires a snapshot of the surrounding environment (Look phase), then executes an appropriate algorithm by using the obtained snapshot as input (Compute phase), and finally moves toward a desired destination, if any (Move phase). In this context, we consider robots that have to visit a partially ordered set of locations. A solution to the problem is the assignment to each robot of a trajectory to follow in order to visit the required locations. The resolution of the task is subject to two main constraints. Robots have to minimize the energy spent to accomplish an assigned trajectory, and they have to avoid collisions among each other. The minimization of the energy is expressed in terms of the number of turns a robot has to perform in between two different locations. This equals the number of bends the assigned trajectory contains in between such locations. In general, the problem is known to require Ω(n) bends per connection, with n being the number of locations, even if considering just two robots involved. We study the case where the locations that a single robot has to visit are represented as colored points in the Euclidean plane, and only two colors are provided. This means the partial order among the locations is just based on two colors per robot. In this case, we provide a constructive solution for two robots with five bends per connection
Light Communication for Controlling Industrial Robots
Full text linkOptical Wireless Communication (OWC) is regarded as an auspicious communication approach that can outperform the existing wireless technology. It utilizes LED lights, whose subtle variation in radiant intensity generate a binary data stream. This is perceived by a photodiode, that converts it to electric signals for further interpretation. This article aims at exploring the use of this emerging technology in order to control wirelessly industrial robots, overcoming the need for wires, especially in environments where radio waves are not working due to environmental factors or not allowed for safety reasons. We performed experiments to ensure the suitability and efficiency of OWC based technology for the aforementioned scope and “in vitro" tests in various Line-of-Sight (LoS) and Non-Line-of-Sight (NLoS) configurations to observe the system throughput and reliability. The technology performance in the “clear LoS" and in the presence of a transparent barrier, were also analyzed
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