942 research outputs found

    Climate Change and Critical Agrarian Studies

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    Climate change is perhaps the greatest threat to humanity today and plays out as a cruel engine of myriad forms of injustice, violence and destruction. The effects of climate change from human-made emissions of greenhouse gases are devastating and accelerating; yet are uncertain and uneven both in terms of geography and socio-economic impacts. Emerging from the dynamics of capitalism since the industrial revolution — as well as industrialisation under state-led socialism — the consequences of climate change are especially profound for the countryside and its inhabitants. The book interrogates the narratives and strategies that frame climate change and examines the institutionalised responses in agrarian settings, highlighting what exclusions and inclusions result. It explores how different people — in relation to class and other co-constituted axes of social difference such as gender, race, ethnicity, age and occupation — are affected by climate change, as well as the climate adaptation and mitigation responses being implemented in rural areas. The book in turn explores how climate change – and the responses to it - affect processes of social differentiation, trajectories of accumulation and in turn agrarian politics. Finally, the book examines what strategies are required to confront climate change, and the underlying political-economic dynamics that cause it, reflecting on what this means for agrarian struggles across the world. The 26 chapters in this volume explore how the relationship between capitalism and climate change plays out in the rural world and, in particular, the way agrarian struggles connect with the huge challenge of climate change. Through a huge variety of case studies alongside more conceptual chapters, the book makes the often-missing connection between climate change and critical agrarian studies. The book argues that making the connection between climate and agrarian justice is crucial

    Enhancement of Charging Resource Utilization of Electric Vehicle Fast Charging Station with Heterogeneous EV Users

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    This thesis presents innovative charging resource allocation and coordination strategies that maximize the limited charging resources at FCS with heterogeneous EV users. It allows opportunistic EV users (OEVs) to exploit available charging resources with dynamic event-driven charging resource allocation and coordination strategies apart from primary EV users (PEVs) (registered or scheduled EV users). Moreover, developed strategies focus on the limited charging resources that are allocated for primary/ registered EV users (PEVs) of the FCS who access the FCS with specific privileges according to prior agreements. But the available resources are not optimally utilized due to various uncertainties associated with the EV charging process such as EV mobility-related uncertainties, EVSE failures, energy price uncertainties, etc. Developed strategies consider that idle chargers and vacant space for EVs at the FCS is an opportunity for further utilizing them with OEVs using innovative charging resource coordination strategies. This thesis develops an FCS-centric performance assessment framework that evaluates the performance of developed strategies in terms of charging resource utilization, charging completion and the quality of service (QoS) aspects of EV users. To evaluate QoS of EV charging process, various parameters such as EV blockage, charging process preemptage, mean waiting time, mean charging time, availability of FCS, charging reliability, etc are derived and analyzed. In addition, the developed innovative charging resource allocation and coordination strategies with resource aggregation and demand elasticity further enhance the charging resource utilization while providing a high QoS in EV charging for both PEVs and OEVs.publishedVersio

    Resilient and Scalable Forwarding for Software-Defined Networks with P4-Programmable Switches

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    Traditional networking devices support only fixed features and limited configurability. Network softwarization leverages programmable software and hardware platforms to remove those limitations. In this context the concept of programmable data planes allows directly to program the packet processing pipeline of networking devices and create custom control plane algorithms. This flexibility enables the design of novel networking mechanisms where the status quo struggles to meet high demands of next-generation networks like 5G, Internet of Things, cloud computing, and industry 4.0. P4 is the most popular technology to implement programmable data planes. However, programmable data planes, and in particular, the P4 technology, emerged only recently. Thus, P4 support for some well-established networking concepts is still lacking and several issues remain unsolved due to the different characteristics of programmable data planes in comparison to traditional networking. The research of this thesis focuses on two open issues of programmable data planes. First, it develops resilient and efficient forwarding mechanisms for the P4 data plane as there are no satisfying state of the art best practices yet. Second, it enables BIER in high-performance P4 data planes. BIER is a novel, scalable, and efficient transport mechanism for IP multicast traffic which has only very limited support of high-performance forwarding platforms yet. The main results of this thesis are published as 8 peer-reviewed and one post-publication peer-reviewed publication. The results cover the development of suitable resilience mechanisms for P4 data planes, the development and implementation of resilient BIER forwarding in P4, and the extensive evaluations of all developed and implemented mechanisms. Furthermore, the results contain a comprehensive P4 literature study. Two more peer-reviewed papers contain additional content that is not directly related to the main results. They implement congestion avoidance mechanisms in P4 and develop a scheduling concept to find cost-optimized load schedules based on day-ahead forecasts

    Cloud computing : developing a cost estimation model for customers

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    Cloud computing is an essential part of the digital transformation journey. It offers many benefits to organisations, including the advantages of scalability and agility. Cloud customers see cloud computing as a moving train that every organisation needs to catch. This means that adoption decisions are made quickly in order to keep up with the new trend. Such quick decisions have led to many disappointments for cloud customers and have questioned the cost of the cloud. This is also because there is a lack of criteria or guidelines to help cloud customers get a complete picture of what is required of them before they go to the cloud. From another perspective, as new technologies force changes to the organizational structure and business processes, it is important to understand how cloud computing changes the IT and non-IT departments and how can this be translated into costs. Accordingly, this research uses the total cost of ownership approach and transaction cost theory to develop a customer-centric model to estimate the cost of cloud computing. The Research methodology used the Design Science Research approach. Expert interviews were used to develop the model. The model was then validated using four case studies. The model, named Sunny, identifies many costs that need to be estimated, which will help to make the cloud-based digital transformation journey less cloudy. The costs include Meta Services, Continuous Contract management, Monitoring and ITSM Adjustment. From an academic perspective, this research highlights the management efforts required for cloud computing and how misleading the rapid provision potential of the cloud resources can be. From a business perspective, proper estimation of these costs would help customers make informed decisions and vendors make realistic promises.Cloud Computing ist ein wesentlicher Bestandteil der Digitalisierung. Es bietet Unternehmen viele Vorteile, wie Skalierbarkeit und Agilität. Cloud-Kunden sehen Cloud Computing als einen Zug, auf den jedes Unternehmen aufspringen muss. Das bedeutet, dass Einführungsentscheidungen schnell getroffen werden, um mit dem neuen Trend Schritt zu halten. Solche Schnellschüsse haben zu vielen Enttäuschungen bei Cloud-Kunden geführt und die Kosten der Cloud in Frage gestellt. Dies ist auch darauf zurückzuführen, dass es keine Kriterien oder Leitlinien gibt, die den Cloud-Kunden helfen, sich ein vollständiges Bild davon zu machen, was von ihnen erwartet wird, bevor sie in die Cloud gehen. Aus einem anderen Blickwinkel ist es wichtig zu verstehen, wie Cloud Computing IT- und Nicht-IT-Abteilungen verändert und wie sich dies auf die Kosten auswirkt, da neue Technologien Veränderungen in der Organisationsstruktur und den Geschäftsprozessen erzwingen. Dementsprechend werden in dieser Forschungsarbeit der Total Cost of Ownership-Ansatz und die Transaktionskostentheorie verwendet, um ein kundenorientiertes Modell zur Schätzung der Kosten von Cloud Computing zu entwickeln. Die Forschungsmethodik basiert auf dem Design Science Research Ansatz. Zur Entwicklung des Modells wurden Experteninterviews durchgeführt. Anschließend wurde das Modell anhand von vier Fallstudien validiert. Das Modell mit dem Namen Sunny identifiziert viele Kosten, die geschätzt werden müssen, um die Reise zur digitalen Transformation in der Cloud weniger wolkig zu gestalten. Zu diesen Kosten gehören Meta-Services, kontinuierliches Vertragsmanagement, Überwachung und ITSM-Anpassung. Aus akademischer Sicht verdeutlicht diese Forschung, welcher Verwaltungsaufwand für Cloud Computing erforderlich ist und wie irreführend das schnelle Bereitstellungspotenzial von Cloud-Ressourcen sein kann. Aus Unternehmenssicht würde eine korrekte Einschätzung dieser Kosten den Kunden helfen, fundierte Entscheidungen zu treffen, und den Anbietern, realistische Versprechungen zu machen

    Coordinated Optimal Voltage Control in Distribution Networks with Data-Driven Methods

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    Voltage control is facing significant challenges with the increasing integration of photovoltaic (PV) systems and electric vehicles (EVs) in active distribution networks. This is leading to major transformations of control schemes that require more sophisticated coordination between different voltage regulation devices in different timescales. Except for conventional Volt/Var control (VVC) devices such on-load tap change (OLTC) and capacitor banks (CBs), inverter-based PVs are encouraged to participate in voltage regulation considering their flexible reactive power regulation capability. With the vehicle to grid (V2G) technology and inverter-based interface at charging stations, the charging power of an EV can be also controlled to support voltages. These emerging technologies facilitate the development of two-stage coordinated optimal voltage control schemes. However, these new control schemes pursue a fast response speed with local control strategies in shorter snapshots, which fails to track the optimal solutions for the distribution system operation. The voltage control methods mainly aim to mitigate voltage violations and reduce network power loss, but they seldom focus on satisfying the various requirements of PV and EV customers. This may discourage customer-owned resources from participating in ancillary services such as voltage regulation. Moreover, model-based voltage control methods highly rely on the accurate knowledge of power system models and parameters, which is sometimes difficult to obtain in real-life distribution networks. The goal of this thesis is to propose a data-driven two-stage voltage control framework to fill the research gaps mentioned above, showing what frameworks, models and solution methods can be used in the optimal voltage control of modern active distribution systems to tackle the security and economic challenges posed by high integration of PVs and EVs

    Recommendations for customer engagement strategies

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    Customers are expected to play a fundamental role in the transition to a decarbonised and digitalised energy system. However, experience so far suggests that customer engagement in energy markets cannot be given for granted. This report investigates those barriers hindering customer engagement in flexibility markets and discusses strategies for their mitigation, aiming to unlock the untapped potential of the resources located at the customer’s premises and foster a more consumer-centric power system. Drawing from an extensive and multi-disciplinary literature review and benefiting from interactions with OneNet cluster demonstrators, this research identifies economic, behavioural, legal, and technical barriers to customer engagement in flexibility markets. Tailored recommendations are provided to surmount each of these barriers, advocating, among other things, for value stacking support, targeted awareness campaigns, regulatory adaptations, and robust infrastructure enhancements

    Energy-aware coordination of machine scheduling and support device recharging in production systems

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    Electricity generation from renewable energy sources is crucial for achieving climate targets, including greenhouse gas neutrality. Germany has made significant progress in increasing renewable energy generation. However, feed-in management actions have led to losses of renewable electricity in the past years, primarily from wind energy. These actions aim to maintain grid stability but result in excess renewable energy that goes unused. The lost electricity could have powered a multitude of households and saved CO2 emissions. Moreover, feed-in management actions incurred compensation claims of around 807 million Euros in 2021. Wind-abundant regions like Schleswig-Holstein are particularly affected by these actions, resulting in substantial losses of renewable electricity production. Expanding the power grid infrastructure is a costly and time-consuming solution to avoid feed-in management actions. An alternative approach is to increase local electricity consumption during peak renewable generation periods, which can help balance electricity supply and demand and reduce feed-in management actions. The dissertation focuses on energy-aware manufacturing decision-making, exploring ways to counteract feed-in management actions by increasing local industrial consumption during renewable generation peaks. The research proposes to guide production management decisions, synchronizing a company's energy consumption profile with renewable energy availability for more environmentally friendly production and improved grid stability

    Circular Economy and Sustainable Development: A Systematic Literature Review

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    Circular Economy put forth as an alternative to traditional linear model of extract-use-dispose along with the concept of Sustainable Development encompassing economic, environmental, and social aspects have garnered tremendous impetus among academics, practitioners and policymakers alike. The UN Sustainable Development Goals embraced by the member nations in 2015 based on the preceding Millenium Development Goals have been placed as the targets to be achieved as a part of holistic human development. In this backdrop, this paper examines the intersection of sustainability and circular economy with a focus on the three aspects of sustainable development, first the economic aspect by examining the relationship between GDP and circular economy, second the social economic aspect within the interaction of Circular Economy with Sustainable development and third the environmental-economical aspect by examining circularity and sustainability in waste management and waste valorisation. This paper achieves its objective through a systematic literature review of 1748 journal articles collected from Web of Science and SCOPUS database following PRISMA standards, network analysis of keywords, and manual review of texts. Four Research Questions are formulated: RQ1: What are the major emergent topics in Circular Economy and Sustainable Development and how are they related? RQ2: What is the relationship among CE and GDP in the CE and Sustainability? RQ3: What are the relationships between CE and Sustainability? RQ4: What are different use cases of valorisation of waste as CE tool, and can valorisation be sustainable? RQ1 is answered by presenting hotspot of research on Circular Economy and Sustainable Development through keywords occurrence network analysis using VosViewer. This study identifies three clusters and seven thematic areas of research, along with 25 most used keywords. RQ2 is attended through review of the relationship between economic growth (Gross Domestic Product) and Circular Economy and proposes based on the review that CE is still at its infancy. The paper also discusses the appropriateness of using GDP as a measure of sustainable development. This paper addresses RQ3 by examining the relationship between Circular Economy and Sustainable Development through review of literatures. The indicators used to measure CE and SD are also discussed and summarised. This review finds that achieving SDGs require greater effort, and that the present status of achievement is a bleak picture. Further, the role of waste management and potentiality of waste valorisation to aid in circular economy and sustainable development is analysed to answer RQ4. Though there are ample potential, however the recycle rate is very minimal to quench the required level of circularity. While CE and SD are related, CE cannot be a universal panacea to global challenges like emissions reduction, energy consumption, climate change, gender equality, poverty, well-being, environmental protection etc. even though the impact of CE to achieve SD can be substantial. The paper recommends avenues for future research and presents the conclusion of the study
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