1,548 research outputs found

    Design and modeling of reliable networks (foreword)

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    Design and optimization of optical grids and clouds

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    Optical Grid Network Dimensioning, Provisioning, and Job Scheduling

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    An optical grid network reliably provides high speed communications. It consists of grid resources (e.g., computing and data servers) and huge-data paths that are connected to geographically dispersed resources and users. One of the important issues is dimensioning optical grid networks, i.e., to determine the link bandwidth utilization and amount of server resources, and finding the location of servers. Another issue is the provisioning of the job requests (maximization of services) on the capacitated networks, also referred to as Grade of Service (GoS). Additionally, job scheduling on the servers has also an important impact on the utilization of computing and network resources. Dimensioning optical grid network is based on Anycast Routing and Wavelength Assignment (ACRWA) with the objective of minimizing (min-ACRWA) the resources. The objective of GoS is maximizing the number of job requests (max-ACRWA) under the limited resources. Given that users of such optical grid networks in general do not care about the exact physical locations of the server resources, a degree of freedom arises in choosing for each of their requests the most appropriate server location. We will exploit this anycast routing principle -- i.e., the source of the traffic is given, but the destination can be chosen rather freely. To provide resilience, traffic may be relocated to alternate destinations in case of network/server failures. This thesis investigates dimensioning optical grids networks and task scheduling. In the first part, we present the link capacity dimensioning through scalable exact Integer Linear Programming (ILP) optimization models (min-ACRWA) with survivability. These models take step by step transition from the classical RWA (fixed destination) to anycast routing principle including shared path protection scheme. In the second part, we present scalable optimization models for maximizing the IT services (max-ACRWA) subject to survivability mechanism under limited link transport capacities. We also propose the link capacity formulations based on the distance from the servers and the traffic data set. In the third part, we jointly investigate the link dimensioning and the location of servers in an optical grid, where the anycast routing principle is applied for resiliency under different levels of protection schemes. We propose three different decomposition schemes for joint optimization of link dimensioning and finding the location of servers. In the last part of this research, we propose the exact task scheduling ILP formulations for optical grids (data centers). These formulations can also be used in advance reservation systems to allocate the grid resources. The purpose of this study is to design efficient tools for planning and management of the optical grid networks

    Storage Protection with Connectivity and Processing Restoration for Survivable Cloud Services

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    The operation and management of software-based communication systems and services is a big challenge for infrastructure and service providers.The challenge is mainly associated with the larger number of configurable elements and the higher dynamicity in the software-based systems compared to the classical ones. On the other hand, the modularity and programmability in software-based networks enabled by technologies like Software Defined Networking (SDN) and Network Function Virtualization (NFV) provide new opportunities for operators to realize advanced network and service management strategies beyond the classical techniques.In our work, we elaborate on these new opportunities and propose a novel strategy for the management of survivable cloud services.In particular, we leverage the flexibility of SDN and NFV to combine proactive protection and reactive restoration mechanisms and we put forward a novel strategy for enhancing the survivability of cloud services. Through comprehensive evaluations, we demonstrate that the proposed strategy offers significant benefits in terms of availability and restorability of services while reducing, at the same time, the overhead caused by the relocation of cloud services in case of failures

    Solar Photovoltaic and Thermal Energy Systems: Current Technology and Future Trends

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    Solar systems have become very competitive solutions for residential, commercial, and industrial applications for both standalone and grid connected operations. This paper presents an overview of the current status and future perspectives of solar energy (mainly photovoltaic) technology and the required conversion systems. The focus in the paper is put on the current technology, installations challenges, and future expectations. Various aspects related to the global solar market, the photovoltaic (PV) modules cost and technology, and the power electronics converter systems are addressed. Research trends and recommendations for each of the PV system sectors are also discussed.Junta de Andalucía P11-TIC-7070Ministerio de Ciencia e Innovación TEC2016-78430-

    Integrating renewable energy resources into the smart grid: recent developments in information and communication technologies

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    Rising energy costs, losses in the present-day electricity grid, risks from nuclear power generation, and global environmental changes are motivating a transformation of the conventional ways of generating electricity. Globally, there is a desire to rely more on renewable energy resources (RERs) for electricity generation. RERs reduce green house gas emissions and may have economic benefits, e.g., through applying demand side management with dynamic pricing so as to shift loads from fossil fuel-based generators to RERs. The electricity grid is presently evolving towards an intelligent grid, the so-called smart grid (SG). One of the major goals of the future SG is to move towards 100% electricity generation from RERs, i.e., towards a 100% renewable grid. However, the disparate, intermittent, and typically widely geographically distributed nature of RERs complicates the integration of RERs into the SG. Moreover, individual RERs have generally lower capacity than conventional fossil-fuel plants, and these RERs are based on a wide spectrum of different technologies. In this article, we give an overview of recent efforts that aim to integrate RERs into the SG. We outline the integration of RERs into the SG along with their supporting communication networks. We also discuss ongoing projects that seek to integrate RERs into the SG around the globe. Finally, we outline future research directions on integrating RERs into the SG

    National Conference on ‘Renewable Energy, Smart Grid and Telecommunication-2023

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    Theme of the Conference: “The challenges and opportunities of integrating renewable energy into the grid” The National Conference on Renewable Energy, Smart Grid, and Telecommunication - 2023 is a platform for industry experts, researchers, and policymakers to come together and explore the latest advancements and challenges in the fields of renewable energy, smart grids, and telecommunication. Conference Highlights: In-depth discussions on renewable energy technologies and innovations. Smart grid integration for a sustainable future. The role of telecommunication in advancing renewable energy solutions. Networking opportunities with industry leaders and experts. Presentation of cutting-edge research papers and case studies. Conference topics: Renewable Energy Technologies and Innovations Smart Grid Development and Implementation Telecommunication for Energy Systems Energy Storage and Grid Balancing Policy, Regulation, and Market Dynamics Environmental and Social Impacts of Renewable Energy Energy Transition and Future Outlook Integration of renewable energy into the grid Microgrids and decentralized energy systems Grid cybersecurity and data analytics IoT and sensor technologies for energy monitoring Data management and analytics in energy sector Battery storage technologies and applicationshttps://www.interscience.in/conf_proc_volumes/1087/thumbnail.jp

    European smart specialization for Ukrainian regional development: path from creation to implementation

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    The focus of the research is to develop recommendations of smart specialization (SS) for Ukrainian policymakers using European approaches. The authors revealed that the main SS projects are presented in such sectors as agri-food, industrial modernization and energy. More than 12 EU countries were the plot for conducted analysis of SS, as a result of which the level of activity of each country was determined. The creation of consortiums, including SMEs, associations, universities and other participants, disclosed the successful way of SS realization. The structure of SME’s innovative potential in Ukraine was identified underlining their main characteristic features like types of innovations and innovative activity, differentiation according to enterprise size, their regional distribution. The authors explored lack of innovations on regional and national level and significant territorial disparities, which could be eliminated through policy implementation of regional SS. The existing legislative norms for possibility of SS implementation in Ukraine were analyzed due to correspondence with the EU ones. The analysis provides the opportunity to consider them only as general framework documents without any action plans and sectoral prioritization at all. The weak points of these law documents are emphasized. As a result of research, the authors developed recommendations presented by direct action plan for Ukrainian policymakers, which include such activities as underlining key priorities (especially ICT applicability in every SS project) and their correspondence with the EU ones; eliminating regional imbalances by focusing on innovation development and reorientation of some regions according to SS priorities; respecting regional existing capacities; providing organizational mechanism for cooperation of stakeholders and financial mechanism for SS support through the EU structural funds
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