Minimization of the network availability upgrade cost with geodiverse routing for disaster resilience

Telecommunication networks are a critical infrastructure of our society. Wide area backbone communication networks are based on optical networks, where each fiber has a very large capacity. These networks must offer high end-to-end availability and a high resilience to large-scale disasters. Routing with geodiversity can mitigate the impact of disasters but will result in longer paths, making it difficult to achieve the availability levels required by critical services. In this paper, we consider a given core optical network such that the current availability and the cost of upgrading it to a higher value are known for each network link (or edge). Then, the problem of selecting a set of edges to be upgraded at a minimum cost, while guaranteeing desired values of end-to-end availability and geodiversity, is considered and formulated as an arc based integer non-linear programming model. The non-linear constraints of the model are approximated and linearized, resulting in a new ILP based heuristic. A filtering procedure is proposed for decreasing (if possible) the cost and the number of upgraded edges of the solutions obtained by previously proposed greedy heuristics and also by the ILP based heuristic. The relative performance of the heuristics is evaluated using different geodiverse distances and end-to-end availability values in two reference core optical networks.publishe

Métodos de melhoria da disponibilidade e da resiliência a desastres em redes de telecomunicações

In current societies, telecommunication networks are one of its essential components, in which different services depend on. Critical service requires these networks to provide high levels of availability between their nodes and high levels of resilient to large-scale natural disasters, either by avoiding them or quickly recover from them. Different techniques can be used to reach these goals. In this dissertation, it is considered the use of geodiversity routing to reduce the impact of large-scale disasters, with the downside of utilizing longer paths which, in turn, reduces the resulting end-to-end availability. This downside can be corrected if the availability of some network elements are upgraded so that the availability required by critical services is met, while maintaining the geodiversity required to prevent the impact of disasters. In this dissertation, different upgrade strategies are implemented to efficiently identify the network elements required to be upgraded, so that the network can provide critical services with high availability and high resilience to natural disasters.As redes de telecomunicações são um dos componentes essenciais na atual sociedade, no qual vários serviços dependem da sua funcionalidade para operarem eficientemente. O suporte de serviços críticos exige que as redes ofereçam altos níveis de disponibilidade entre os seus nós e sejam altamente resilientes a desastres de larga escala, tais como os provocados por fenómenos naturais (tremores de terra, tsunamis, etc.). Algumas técnicas podem ser implementadas para atingir estes objetivos. Nesta dissertação, considera-se o uso de encaminhamento com geodiversidade para reduzir o impacto de desastres de larga escala, com a desvantagem de exigir percursos de encaminhamento mais longos, reduzindo a disponibilidade resultante entre os nós origem-destino do encaminhamento. Assim, para obter simultaneamente alta disponibilidade e alta resiliência a desastres, é necessário melhorar a disponibilidade em alguns elementos da rede. Nesta dissertação são introduzidas diferentes estratégias para identificar eficazmente os elementos da rede que precisam de ser melhorados em termos de disponibilidade, para que a rede suporte os requisitos de disponibilidade e resiliência a desastres requeridos por serviços críticos.Mestrado em Engenharia Informátic

The minimum cost D-geodiverse anycast routing with optimal selection of anycast nodes

Consider a geographical network with associated link costs. In anycast routing, network nodes are partitioned into two sets - the source nodes and the anycast (destination) nodes - and the traffic of each source node is routed towards the anycast node providing the minimum routing cost path. By considering a given geographical distance parameter D, we define an anycast routing solution as D-geodiverse when for each source node there are two routing paths, each one towards a different anycast node, such that the geographical distance between the two paths is at least D. Such a solution has the property that any disaster with a coverage diameter below D affecting one routing path (but without involving neither the source node nor its entire set of outgoing links) cannot affect the other path, enhancing in this way the network robustness to natural disasters. The selection of the anycast nodes has an impact both on the feasibility and cost of a D- geodiverse anycast routing solution. Therefore, for a desired number of anycast nodes R, we define the minimum cost D- geodiverse anycast problem (MCD-GAP) aiming to identify a set of R anycast nodes that obtain a minimum cost routing solution. The problem is defined based on integer linear programming and is extended to consider the existence of vulnerability regions in the network, i.e., by imposing the geographical distance D only between network elements belonging to the same region. We present computational results showing the tradeoff between D and R in the optimal solutions obtained with and without vulnerability regions.This paper is based upon work from COST Action CA15127 ("Resilient communication services protecting end user applications from disaster-based failures ‒ RECODIS") supported by COST Association. The work was financially supported by FCT, Portugal, under the projects CENTRO- 01-0145-FEDER-029312 and UID/EEA/50008/2013 and through the postdoc grant SFRH/BPD/ 111503/2015.publishe

Renewable energy in the food, energy, water Nexus of the Bahamas

As the global population increases, so does global demand for energy, water and food expand. Meeting this continual spike of demand presents a tremendous challenge to Small Island States, given competing needs for limited resources amid heightened climate change. In order to overcome the increasing constraints that Small Island States encounter, serious consideration must be given with respect to how Small Island States produce and consume energy, produce water and provide food to their citizens. This critical tri-partied interaction is known as the Nexus. The interlinkage between the water, energy and food supply systems is a major consideration in countries’ sustainable development strategies. Rapid economic growth, expanding populations and increasing prosperity are driving up demand for energy, water and food, especially in the Small Island States in the developing countries. Advancements in renewable energy technologies provide access to cost-effective, secure and environmentally sustainable supplies of energy. Their rapid technology advancements can have substantial spill-over effects in the water and food sectors. Yet detailed knowledge on the role renewables can play in the management of the Nexus remains limited and widely dispersed, let alone aggressively practiced or not practiced in small island countries such as the Bahamas. Renewable energy technologies could address some of the trade-offs between water, energy and food, bringing substantial benefits in all three sectors. The objective of the Thesis is to explore whether Small Island States such as the Bahamas are taking full advantage of the current technology available to manage their Nexus. The Thesis primarily uses government policies and press reporting on Bahamian renewable energy projects, and how these programs influence the water, energy and food requirements for the Bahamas. The term "energy-water-food Nexus" refers to the complex interdependencies between energy, water and agriculture that vary by geography. The Nexus refers to the web of interactions that link energy, water and food in a common system, as growing food requires water, processing water requires power, and hydro-electric power generation requires water. Depleting the natural resources of islands to the point of annihilation is verifiable in island countries such as the Easter Islands. Small islands are a microcosm of the Earth. To study small island Nexus topics is an opportunity to understand the challenges experienced all over the world

Management, Technology and Learning for Individuals, Organisations and Society in Turbulent Environments

This book presents the collection of fifty two papers which were presented on the First International Conference on BUSINESS SUSTAINABILITY ’08 - Management, Technology and Learning for Individuals, Organisations and Society in Turbulent Environments, held in Ofir, Portugal, from 25th to 27th of June, 2008. The main motive of the meeting was the growing awareness of the importance of the sustainability issue. This importance had emerged from the growing uncertainty of the market behaviour that leads to the characterization of the market, i.e. environment, as turbulent. Actually, the characterization of the environment as uncertain and turbulent reflects the fact that the traditional technocratic and/or socio-technical approaches cannot effectively and efficiently lead with the present situation. In other words, the rise of the sustainability issue means the quest for new instruments to deal with uncertainty and/or turbulence. The sustainability issue has a complex nature and solutions are sought in a wide range of domains and instruments to achieve and manage it. The domains range from environmental sustainability (referring to natural environment) through organisational and business sustainability towards social sustainability. Concerning the instruments for sustainability, they range from traditional engineering and management methodologies towards “soft” instruments such as knowledge, learning, creativity. The papers in this book address virtually whole sustainability problems space in a greater or lesser extent. However, although the uncertainty and/or turbulence, or in other words the dynamic properties, come from coupling of management, technology, learning, individuals, organisations and society, meaning that everything is at the same time effect and cause, we wanted to put the emphasis on business with the intention to address primarily the companies and their businesses. From this reason, the main title of the book is “Business Sustainability” but with the approach of coupling Management, Technology and Learning for individuals, organisations and society in Turbulent Environments. Concerning the First International Conference on BUSINESS SUSTAINABILITY, its particularity was that it had served primarily as a learning environment in which the papers published in this book were the ground for further individual and collective growth in understanding and perception of sustainability and capacity for building new instruments for business sustainability. In that respect, the methodology of the conference work was basically dialogical, meaning promoting dialog on the papers, but also including formal paper presentations. In this way, the conference presented a rich space for satisfying different authors’ and participants’ needs. Additionally, promoting the widest and global learning environment and participativeness, the Conference Organisation provided the broadcasting over Internet of the Conference sessions, dialogical and formal presentations, for all authors’ and participants’ institutions, as an innovative Conference feature. In these terms, this book could also be understood as a complementary instrument to the Conference authors’ and participants’, but also to the wider readerships’ interested in the sustainability issues. The book brought together 97 authors from 10 countries, namely from Australia, Finland, France, Germany, Ireland, Portugal, Russia, Serbia, Sweden and United Kingdom. The authors “ranged” from senior and renowned scientists to young researchers providing a rich and learning environment. At the end, the editors hope and would like that this book will be useful, meeting the expectation of the authors and wider readership and serving for enhancing the individual and collective learning, and to incentive further scientific development and creation of new papers. Also, the editors would use this opportunity to announce the intention to continue with new editions of the conference and subsequent editions of accompanying books on the subject of BUSINESS SUSTAINABILITY, the second of which is planned for year 2011.info:eu-repo/semantics/publishedVersio

Minimizing the network availability upgrade cost with geodiversity guarantees

As telecommunication networks are a critical infrastructure of our society, they must evolve to provide high end-to-end availability and high resilience to large-scale disasters. Path protection mechanisms can improve end-to-end availability but, in general, might not be enough to reach the availability required by critical services. Moreover, adding geodiversity to the routing paths (i.e., selecting path pairs with higher geographical distance between them) enhances the network disaster resilience but also makes it more challenging to reach a high end-to-end availability as the resulting paths tend to be longer. So, for a network where each link is characterized by its current availability and by the cost of upgrading its availability to a new value, this paper proposes some strategies aiming to determine a set of links to be upgraded at a minimum cost ensuring a desired level of availability and geodiversity. The problem is defined as an integer non-linear programming model, a solving algorithm based on different greedy strategies is proposed and the relative performance of the different strategies is evaluated on a set of problem instances

Best Environmental Management Practice in the Tourism Sector

The tourism sector has a large potential to reduce its environmental impacts and many measures are already effectively implemented by companies of this sector. This document describes what are the best practices employed by frontrunners in all aspects under their direct control or on which they have a considerable influence. They cover cross-cutting issues, destination management, tour operators and travel agents, water and energy consumption and waste production in accommodation, restaurant and hotel kitchens, and campsites management. The document also contains sector-specific environmental performance indicators and benchmarks of excellence. These can be used by all the actors involved in the tourism sector to monitor their environmental performance and to benchmark it against the performance of frontrunners in each given specific area. Overall, this document aims at supporting all actors in the tourism sector who intend to improve their environmental performance and seek for reliable and proven information on how best to do it.JRC.J.5-Sustainable Production and Consumptio

Hyperspectral Imaging for Fine to Medium Scale Applications in Environmental Sciences

The aim of the Special Issue “Hyperspectral Imaging for Fine to Medium Scale Applications in Environmental Sciences” was to present a selection of innovative studies using hyperspectral imaging (HSI) in different thematic fields. This intention reflects the technical developments in the last three decades, which have brought the capacity of HSI to provide spectrally, spatially and temporally detailed data, favoured by e.g., hyperspectral snapshot technologies, miniaturized hyperspectral sensors and hyperspectral microscopy imaging. The present book comprises a suite of papers in various fields of environmental sciences—geology/mineral exploration, digital soil mapping, mapping and characterization of vegetation, and sensing of water bodies (including under-ice and underwater applications). In addition, there are two rather methodically/technically-oriented contributions dealing with the optimized processing of UAV data and on the design and test of a multi-channel optical receiver for ground-based applications. All in all, this compilation documents that HSI is a multi-faceted research topic and will remain so in the future

Environmental trends in Montenegro: Land degradation neutrality

Land degradation neutrality (LDN) is an integral part of the 2030 UN Agenda for Sustainable Development. Montenegro actively works on LDN target setting process. This paper aims to present: (a) the basic principles of LDN concept, (b) global datasets provided by UNCCD, (c) SWOT analysis for the country, and (d) to discuss possible national datasets and further activities related to LDN. LDN Target indicator is measured by means of three sub-indicators: land cover, land productivity and soil organic carbon (SOC), and it could be broaden with national indicators. Country has been provided by UNCCCD with global dataset on three sub-indicators, as well as with watershed boundaries, but is encouraged to utilize their own datasets. ESA land cover data indicate the conversion of 2460 ha of forests into to croplands or shrubs. Land productivity dynamics data indicated that 74300 ha of territory have sort of negative trends in land productivity. SOC at the country level indicates average content of 125.1 t/ha. Ten potential hotspots in the country had reduction of land productivity dynamics caused by wildfires, whereas five hotspots had multiple drivers of land degradation among which fires, agricultural abandonment and urbanization are the most important. Although there is a certain inaccuracy in global datasets, the country decision is to utilize them in defining LDN baseline. The national working group defined four specific voluntary targets: (1) Avoiding, minimizing land degradation, and redirecting land use changes, (2) Increase of land productivity - reduction of soil degradation, (3), Protection of natural ecosystems from wildfires, and (4) Improvement of soil monitoring system. Accordingly, 25 associated measures are defined to achieve LDN up to 2030. They are related to enhancement of LDN baseline in Montenegro, environmental legislations, direct measures to prevent, minimize land degradation and restore degraded land, sustainable agriculture and forestry, land use changes and social