A Novel Shortcut Addition Algorithm With Particle Swarm for Multisink Internet of Things

[EN] The Internet of Things integrates a large number of distributed nodes to collect or transmit data. When the network scale increases, individuals use multiple sink nodes to construct the network. This increases the complexity of the network and leads to significant challenges in terms of the existing methods with respect to the aspect of data forwarding and collection. In order to address the issue, this paper proposes a Shortcut Addition strategy based on the Particle Swarm algorithm (SAPS) for multisink network. It constructs a network topology with multiple sinks based on a small-world network. In the SAPS, we create a fitness function by combining the average path length and load of the sink node, to evaluate the quality of a particle. Subsequently, crossover and mutation are used to update the particles to determine the optimal solution. The simulation results indicate that the SAPS is superior both to the greedy model with small world and the load-balanced multigateway aware long link addition strategy in terms of the average path length, load balance, and number of added shortcuts.This work was supported by the National Natural Science Foundation of China under Grant 61672131 and Grant 61702365. Paper no. TII-19-0511.Qiu, T.; Li, B.; Zhou, X.; Song, H.; Lee, I.; Lloret, J. (2020). A Novel Shortcut Addition Algorithm With Particle Swarm for Multisink Internet of Things. IEEE Transactions on Industrial Informatics. 16(5):3566-3577. https://doi.org/10.1109/TII.2019.29250233566357716

Efficient Content Location Using Semantic Small World in Peer-to-Peer Networks

        Locating content in unstructured peer-to-peer networks is a challenging problem. This paper presents a novel semantic small world resource search mechanism to address the problem. By using vector space model to compute the semantic relevance and applying small world properties such as low average hop distance and high clustering coefficient to construct a cluster overlay. In semantic small world system, the search mechanism is divided into two parts, searching at cluster and outside cluster through inner link and short link, so that it can achieve the incremental research. It significantly reduces the average path length and query cost. Meanwhile, the simulation results show that semantic small world scheme outperforms K-random walks and flooding scheme than higher query hit rate and lower query latency

Quality-of-service in wireless sensor networks: state-of-the-art and future directions

Wireless sensor networks (WSNs) are one of today’s most prominent instantiations of the ubiquituous computing paradigm. In order to achieve high levels of integration, WSNs need to be conceived considering requirements beyond the mere system’s functionality. While Quality-of-Service (QoS) is traditionally associated with bit/data rate, network throughput, message delay and bit/packet error rate, we believe that this concept is too strict, in the sense that these properties alone do not reflect the overall quality-ofservice provided to the user/application. Other non-functional properties such as scalability, security or energy sustainability must also be considered in the system design. This paper identifies the most important non-functional properties that affect the overall quality of the service provided to the users, outlining their relevance, state-of-the-art and future research directions

Value-of-Information based Data Collection in Underwater Sensor Networks

Underwater sensor networks are deployed in marine environments, presenting specific challenges compared to sensor networks deployed in terrestrial settings. Among the major issues that underwater sensor networks face is communication medium limitations that result in low bandwidth and long latency. This creates problems when these networks need to transmit large amounts of data over long distances. A possible solution to address this issue is to use mobile sinks such as autonomous underwater vehicles (AUVs) to offload these large quantities of data. Such mobile sinks are called data mules. Often it is the case that a sensor network is deployed to report events that require immediate attention. Delays in reporting such events can have catastrophic consequences. In this dissertation, we present path planning algorithms that help in prioritizing data retrieval from sensor nodes in such a manner that nodes that require more immediate attention would be dealt with at the earliest. In other words, the goal is to improve the Quality of Information (QoI) retrieved. The path planning algorithms proposed in this dissertation are based on heuristics meant to improve the Value of Information (VoI) retrieved from a system. Value of information is a construct that helps in encoding the valuation of an information segment i.e. it is the price an optimal player would pay to obtain a segment of information in a game theoretic setting. Quality of information and value of information are complementary concepts. In this thesis, we formulate a value of information model for sensor networks and then consider the constraints that arise in underwater settings. On the basis of this, we develop a VoI-based path planning problem statement and propose heuristics that solve the path planning problem. We show through simulation studies that the proposed strategies improve the value, and hence, quality of the information retrieved. It is important to note that these path planning strategies can be applied equally well in terrestrial settings that deploy mobile sinks for data collection

A reputation-based mechanism to mitigate host misbehaviors in DTNs

Delay Tolerant Networking (DTN) is a network paradigm designed for disconnected networks. Message delivery in DTNs relies on the mobility of carriers, hosts that carry messages from a network partition to another. Context-Aware Adaptive Routing (CAR) is a routing protocol for DTNs with the aim to select the carrier with the highest chance of successful message delivery. CAR relies on the assumption that all hosts in the network are collaborative, i.e. that cooperate in the message forwarding process. In real-life environments hosts can not cooperate in such process and endanger communication among partitions. We propose RCAR, a decentralized approach based on reputation aimed to detect and exclude misbehaving hosts from the network. Simulation tests made on a human mobility model show that RCAR increases the message delivery probability of CAR in presence of misbehaving carriers. Delay Tolerant Networking (DTN) è un paradigma di comunicazione progettato per reti caratterizzate da elevati ritardi e frequenti disconnessioni. La comunicazione fra dispositivi posizionati in partizioni di rete differenti avviene sfruttando la mobilità dei cosiddetti carriers, dispositivi che trasportano fisicamente un messaggio da una partizione di rete all'altra per conto di un altro dispositivo. Context-Aware Adaptive Routing (CAR) è un protocollo di routing per DTN che seleziona il carrier avente la più elevata probabilità di corretta consegna di un messaggio. Il corretto funzionamento di CAR fa affidamento sulla collaborazione di tutti i carriers nel processo di consegna di un messaggio. In sistemi reali però i carriers possono non partecipare a tale processo, mettendo quindi a rischio la comunicazione. Questo documento presenta RCAR, un meccanismo di sicurezza basato sul concetto di reputazione volto ad individuare ed escludere i carriers non collaborativi dal processo di consegna dei messaggi. I risultati di simulazioni effettuate utilizzando un modello di mobilità realistico dei dispositivi mostrano come RCAR aumenti la percentuale di messaggi consegnati correttamente rispetto a CAR in presenza di carriers non collaborativi

A framework for the visualisation and control of ubiquitous devices, services and digital content

The General Organization for Technical Education and Vocational Training, Riyadh, Saudi Arabia, has developed a special feeding program for the students at its institutions. The effects of this program on the nutritional and health status of these students have not been evaluated yet, and since no published dietary research has been performed on Technical and Vocational young adult male students, the present work was undertaken to investigate the nutritional status of this community in Riyadh, Kingdom of Saudi Arabia. After a pilot survey, it was decided to use a selfcompleted questionnaire combined with personal interview to investigate the nutritional status of 690 students randomly selected from the study population. Dietary data was collected by two methods: usual weekly intakes "diet history" and actual daily intakes "diet diary". The nutrient intakes were calculated using the unilever Dietary Analysis Program (UNIDAP). The statistical Package for the social Science (SPSS/PC+) was employed to analyse the data; statistical significance of relationships between certain sets of data was determined by chi-square analysis. Some general factors affecting the nutritional status of these students were identified, their nutritional habits and attitudes were investigated, and the average daily intakes of energy, the macronutrients, and selected micronutrients were calculated. The main results of this study shows that the majority of the study population are adolescent, moderately active individuals, and have lower than the standard range of the Body Mass Index; anaemia is the most stated health problem; meal-skipping and eating between meals are common habits amongst the students. Regarding nutrient intake, there was an energy, polyunsaturated fat, and vitamin C deficiency; adequate intake of saturated fat, dietary fibre, retinol, and zinc; more than adequate intake of protein, total fat, cholesterol, thiamin, riboflavin, calcium, and iron. Recommendations are given which aim to improve the nutrition of technical and vocational students

'The Mula Ring': Material Flows of Circulation Through the Cuban World

This thesis explores the permeability of what is arguably one of the most politicised and reified ‘frontiers’ in the world: that between the U.S. and Cuba. Despite decades of diplomatic hostilities and economic sanctions, the border between Miami and Havana is in a state of constant flux, with ceaseless flows of both people and things moving in both directions. Drawing upon fifteen months of ethnographic research primarily in Miami and Havana (2017-2018), and also in Panama, Mexico and Guyana, this thesis traces these ‘flows’ to understand how and why these material and digital flows constitute everyday life for millions of Cubans who, notwithstanding this political rhetoric, seek to maintain personal and business relationships. The thesis presents personal stories based on these flows to examine the shifting relationship between Cuba and its diaspora. Cubans in both Miami and Cuba are negotiating materiality and digital networks within their own plural notions of cubanidad (‘Cubanness’), capitalism and socialism, and according to their own geopolitical and socioeconomic contexts. By focusing on the inconsequential objects of the everyday, and centring on notions of ‘flow’ and ‘flux’, this thesis seeks to show how a politically and economically turbulent landscape is experienced and reconfigured at a micro level by ordinary Cubans on both sides of the Florida Straits who, by the happenstance of their birth right, must negotiate extraordinary and difficult conditions on a daily basis to maintain their family connections, cultural identity, and ultimately, to live what they consider to be meaningful lives. The thesis shows how it is only through a slippage in traditional categories of ‘people’ and ‘things’ that such flows are made possible, and then positions this observation within theoretical arguments that situate rupture as crucial for the emergence of new cultural forms

Urubu: energy scavenging in wireless sensor networks

For the past years wireless sensor networks (WSNs) have been coined as one of the most promising technologies for supporting a wide range of applications. However, outside the research community, few are the people who know what they are and what they can offer. Even fewer are the ones that have seen these networks used in real world applications. The main obstacle for the proliferation of these networks is energy, or the lack of it. Even though renewable energy sources are always present in the networks environment, designing devices that can efficiently scavenge that energy in order to sustain the operation of these networks is still an open challenge. Energy scavenging, along with energy efficiency and energy conservation, are the current available means to sustain the operation of these networks, and can all be framed within the broader concept of “Energetic Sustainability”. A comprehensive study of the several issues related to the energetic sustainability of WSNs is presented in this thesis, with a special focus in today’s applicable energy harvesting techniques and devices, and in the energy consumption of commercially available WSN hardware platforms. This work allows the understanding of the different energy concepts involving WSNs and the evaluation of the presented energy harvesting techniques for sustaining wireless sensor nodes. This survey is supported by a novel experimental analysis of the energy consumption of the most widespread commercially available WSN hardware platforms.Há já alguns anos que as redes de sensores sem fios (do Inglês Wireless Sensor Networks - WSNs) têm sido apontadas como uma das mais promissoras tecnologias de suporte a uma vasta gama de aplicações. No entanto, fora da comunidade científica, poucas são as pessoas que sabem o que elas são e o que têm para oferecer. Ainda menos são aquelas que já viram a sua utilização em aplicações do dia-a-dia. O principal obstáculo para a proliferação destas redes é a energia, ou a falta dela. Apesar da existência de fontes de energia renováveis no local de operação destas redes, continua a ser um desafio construir dispositivos capazes de aproveitar eficientemente essa energia para suportar a operação permanente das mesmas. A colheita de energia juntamente com a eficiência energética e a conservação de energia, são os meios disponíveis actualmente que permitem a operação permanente destas redes e podem ser todos englobados no conceito mais amplo de “Sustentabilidade Energética”. Esta tese apresenta um estudo extensivo das várias questões relacionadas com a sustentabilidade energética das redes de sensores sem fios, com especial foco nas tecnologias e dispositivos explorados actualmente na colheita de energia e no consumo energético de algumas plataformas comercias de redes de sensores sem fios. Este trabalho permite compreender os diferentes conceitos energéticos relacionados com as redes de sensores sem fios e avaliar a capacidade das tecnologias apresentadas em suportar a operação permanente das redes sem fios. Este estudo é suportado por uma inovadora análise experimental do consumo energético de algumas das mais difundidas plataformas comerciais de redes de sensores sem fios