Design and Implementation of Lightweight Certificateless Secure Communication Scheme on Industrial NFV-Based IPv6 Virtual Networks

With the fast growth of the Industrial Internet of Everything (IIoE), computing and telecommunication industries all over the world are moving rapidly towards the IPv6 address architecture, which supports virtualization architectures such as Network Function Virtualization (NFV). NFV provides networking services like routing, security, storage, etc., through software-based virtual machines. As a result, NFV reduces equipment costs. Due to the increase in applications on Industrial Internet of Things (IoT)-based networks, security threats have also increased. The communication links between people and people or from one machine to another machine are insecure. Usually, critical data are exchanged over the IoE, so authentication and confidentiality are significant concerns. Asymmetric key cryptosystems increase computation and communication overheads. This paper proposes a lightweight and certificateless end-to-end secure communication scheme to provide security services against replay attacks, man-in-the-middle (MITM) attacks, and impersonation attacks with low computation and communication overheads. The system is implemented on Linux-based Lubuntu 20.04 virtual machines using Java programming connected to NFV-based large-scale hybrid IPv4-IPv6 virtual networks. Finally, we compare the performance of our proposed security scheme with existing schemes based on the computation and communication costs. In addition, we measure and analyze the performance of our proposed secure communication scheme over NFV-based virtualized networks with regard to several parameters like end-to-end delay and packet loss. The results of our comparison with existing security schemes show that our proposed security scheme reduces the computation cost by 38.87% and the communication cost by 26.08%

Smart city communication via social media: analysing residents’ and visitors’ engagement

This research applies a unique conceptual model and methodology incorporating popularity, commitment, and virality to measure the social media engagement with residents and visitors of smart cities and how they communicate ‘smart’ elements and their brands. Digital content analysis was applied to a sample of ten Spanish smart cities (including Barcelona, Bilbao, Madrid, Seville and Valencia, among others), with measurable and quantifiable elements of engagement (e.g., likes, shares and comments). The smart cities analysed achieved acceptable, but rudimentary, levels of engagement via social media using Facebook, Twitter and Instagram. However, they displayed weaknesses related to their image and branding as well as the effectiveness with which they communicated their smart characteristics. The main implication of this research is that these Spanish smart cities have considerable scope to improve their use of social media to enhance their communications and branding. Greater emphasis is required on delivering emotional (affective) messages and a higher priority needs to be given to business and business event travellers and those visiting friends and relatives

Single-ended limiting inductor voltage-ratio-derivative protection scheme for VSC-HVDC grids

Single-ended protection systems present the characteristics needed to fulfil the restrictive speed requirement related to high voltage direct current grids. This paper proposes a novel single-ended protection algorithm based on the DC voltage across the limiting inductors placed at each link end. Voltage measurements are taken at both terminals of the limiting inductors. The ratio between the link- and bus-side voltages enables fault discrimination between forward and backward fault conditions while providing directionality. Moreover, the derivative of the voltage-ratio is calculated in order to enable fast fault detection. The combined operation of these two algorithms avoids nuisance operations against fluctuations and close-up external faults. A trip signal is only issued to the circuit breakers when the individual criteria of both algorithms are simultaneously fulfilled. According to this, a protection scheme is developed, which covers link primary and backup as well as busbar protections. The performance of the proposed protection scheme is evaluated through simulations in a four-terminal grid. The selective, sensitive and accurate performance of the proposed protection scheme is demonstrated against faults up to 250 Ω while employing only local measurements, common limiting inductor sizes and a relatively low sampling frequency. Thus, the proposed protection scheme overcomes the sensitivity limitations related to high-resistance fault detection presented in derivative-based algorithms. Its proper operation under noise disturbances is also demonstrated.The authors gratefully acknowledge the support from the Basque Government (GISEL research group IT1522-22) and the University of the Basque Country UPV/EHU (PIF 20/06)

Short-circuit analytical model for modular multilevel converters considering DC cable capacitance

Developing analytical short-circuit models for Modular Multilevel Converters (MMC) is not straightforward due to their switching and blocking characteristics. Short-circuit models for MMCs have been developed previously in the literature. However, there is a lack of understanding regarding the dynamics in the short-circuit model when the DC cable capacitance is taken into account. Therefore, this work proposes an analytical pole-To-pole short-circuit model for half-bridge MMCs that considers the cable capacitance and terminal capacitors and accounts their contribution to fault dynamics. An approximated analytical model has been derived separating the system solutions in different natural frequencies. The proposed model provides an excellent approximation for a vast range of realistic system parameters. The analytical model reproduced the behaviour of the variables in the time domain and provided a clear basis for interpreting the dynamics of the voltages and currents involved

Artificial neural network based adaptive control of single phase Dual Active Bridge with finite time disturbance compensation

Single phase Dual Active Bridge (DAB) has found numerous applications in modern energy architectures such as direct current (DC) microgrid, electrical vehicle charging and high voltage direct current (HVDC) system. Due to the model complexities of DAB, this work proposes a model free adaptive control method based on artificial neural network (AANN) which is capable of adjusting the weights online in finite time. The finite time learning property of the proposed controller makes it perfectly robust for the compensation of the disturbances due to source and load side variations. A proportional integral (PI) controller is used to stabilize the nominal dynamics of the system along with the AANN controller. The structure of the proposed controller is as simple as PID controller and as robust as any nonlinear control method. The AANN-PI controller is implemented on TI Launchpad (TMS320F28379D) with a 50 Watts laboratory scale DAB test bench. Finally, the performance of the AANN-PI method is compared experimentally with classical PI and sliding mode controllers

Big Data Optimization : Algorithmic Framework for Data Analysis Guided by Semantics

Fecha de Lectura de Tesis: 9 noviembre 2018.Over the past decade the rapid rise of creating data in all domains of knowledge such as traffic, medicine, social network, industry, etc., has highlighted the need for enhancing the process of analyzing large data volumes, in order to be able to manage them with more easiness and in addition, discover new relationships which are hidden in them Optimization problems, which are commonly found in current industry, are not unrelated to this trend, therefore Multi-Objective Optimization Algorithms (MOA) should bear in mind this new scenario. This means that, MOAs have to deal with problems, which have either various data sources (typically streaming) of huge amount of data. Indeed these features, in particular, are found in Dynamic Multi-Objective Problems (DMOPs), which are related to Big Data optimization problems. Mostly with regards to velocity and variability. When dealing with DMOPs, whenever there exist changes in the environment that affect the solutions of the problem (i.e., the Pareto set, the Pareto front, or both), therefore in the fitness landscape, the optimization algorithm must react to adapt the search to the new features of the problem. Big Data analytics are long and complex processes therefore, with the aim of simplify them, a series of steps are carried out through. A typical analysis is composed of data collection, data manipulation, data analysis and finally result visualization. In the process of creating a Big Data workflow the analyst should bear in mind the semantics involving the problem domain knowledge and its data. Ontology is the standard way for describing the knowledge about a domain. As a global target of this PhD Thesis, we are interested in investigating the use of the semantic in the process of Big Data analysis, not only focused on machine learning analysis, but also in optimization

Cascaded- and Modular-Multilevel Converter Laboratory Test System Options: A Review

The increasing importance of cascaded multilevel converters (CMCs), and the sub-category of modular multilevel converters (MMCs), is illustrated by their wide use in high voltage DC connections and in static compensators. Research is being undertaken into the use of these complex pieces of hardware and software for a variety of grid support services, on top of fundamental frequency power injection, requiring improved control for non-traditional duties. To validate these results, small-scale laboratory hardware prototypes are often required. Such systems have been built by many research teams around the globe and are also increasingly commercially available. Few publications go into detail on the construction options for prototype CMCs, and there is a lack of information on both design considerations and lessons learned from the build process, which will hinder research and the best application of these important units. This paper reviews options, gives key examples from leading research teams, and summarizes knowledge gained in the development of test rigs to clarify design considerations when constructing laboratory-scale CMCs.This work was supported in part by The University of Manchester supported by the National Innovation Allowance project ``VSC-HVDC Model Validation and Improvement'' and Dr. Heath's iCASE Ph.D. studentship supported through Engineering and Physical Sciences Research Council (EPSRC) and National Grid, in part by the Imperial College London supported by EPSRC through the HubNet Extension under Grant EP/N030028/1, in part by an iCASE Ph.D. Studentship supported by EPSRC and EDF Energy and the CDT in Future Power Networks under Grant EP/L015471/1, in part by University of New South Wales (UNSW) supported by the Solar Flagships Program through the Education Infrastructure Fund (EIF), in part by the Australian Research Council through the Discovery Early Career Research Award under Grant DECRA_DE170100370, in part by the Basque Government through the project HVDC-LINK3 under Grant ELKARTEK KK-2017/00083, in part by the L2EP research group at the University of Lille supported by the French TSO (RTE), and in part by the Hauts-de-France region of France with the European Regional Development Fund under Grant FEDER 17007725

Embracing the future Internet of Things

All of the objects in the real world are envisioned to be connected and/or represented, through an infrastructure layer, in the virtual world of the Internet, becoming Things with status information. Services are then using the available data from this Internet-of-Things (IoT) for various social and economical benefits which explain its extreme broad usage in very heterogeneous fields. Domain administrations of diverse areas of application developed and deployed their own IoT systems and services following disparate standards and architecture approaches that created a fragmentation of things, infrastructures and services in vertical IoT silos. Coordination and cooperation among IoT systems are the keys to build “smarter” IoT services boosting the benefits magnitude. This article analyses the technical trends of the future IoT world based on the current limitations of the IoT systems and the capability requirements. We propose a hyper-connected IoT framework in which “things” are connected to multiple interdependent services and describe how this framework enables the development of future applications. Moreover, we discuss the major limitations in today’s IoT and highlight the required capabilities in the future. We illustrate this global vision with the help of two concrete instances of the hyper-connected IoT in smart cities and autonomous driving scenarios. Finally, we analyse the trends in the number of connected “things” and point out open issues and future challenges. The proposed hyper-connected IoT framework is meant to scale the benefits of IoT from local to global

New protection algorithms for HVDC grids

233 p.Los sistemas HVDC representan una alternativa prometedora para futuras expansiones del sistema eléctrico gracias a las ventajas que presentan en comparación con el transporte convencional en corriente alterna. Además, el interés por desarrollar redes HVDC multiterminales ha crecido en los últimos años, sin embargo, su implementación se ha visto ralentizada debido a la complejidad que presenta la protección ante faltas en estos sistemas. El objetivo principal de esta tesis es proponer un nuevo algoritmo de protección contra faltas, apropiado para dichas redes y capaz de superar las limitaciones presentes en algoritmos existentes. El algoritmo propuesto es un algoritmo de tensión de inductancia basado en el cálculo del ratio entre las medidas de tensión tomadas a ambos lados de la inductancia limitadora y la derivada de dicho ratio. Es capaz de detectar faltas rápidamente y de discriminar de manera selectiva entre faltas dentro y fuera de la zona de protección. También se propone una metodología para la selección del valor umbral necesario para la operación de algoritmos locales. A continuación, sedesarrolla un esquema de protección completo que se compone de protecciones de línea primaria y de respaldo, protección de barra y protección ante fallo del interruptor. Esta última protección es, así mismo, un nuevo algoritmo propuesto en la tesis, que presenta una operación más rápida que algoritmos convencionales de detección de fallo en el interruptor. Finalmente, la operación del esquema de protección propuesto es validada y analizada a través de simulaciones en un modelo de red de cuatro terminales con diferentes escenarios de falta, comparándolo con algoritmos existentes

FabLabs: The Road to Distributed and Sustainable Technological Training through Digital Manufacturing

The fast expansion of digital culture has fostered the creation of makerspaces such as fabrication laboratories (FabLabs) that, thanks to their flexibility and their use of open source tools, strengthen the sense of community and produce true transformations within those communities. Despite their relevance, few studies focus on the characterization of these environments. This paper presents the results of the FabLab Global Survey, aimed at understanding the characteristics of FabLabs through the visions of their managers, or "FabManagers". The results show an enormous diversity of approaches within the FabLab movement that cannot be extrapolated to a single characteristic element, but that allow its global compression. Their properties reveal them as transforming elements that eliminate technological and cultural barriers, empowering user communities and optimizing learning processes regarding digital technology. FabLab activities allow not only economic and industrial development thanks to innovative projects, but also a digital technology approach for young students and the inclusion of minorities at risk, thus eliminating old cultural and social barriers