45 research outputs found

    Education and training needs, methods, and tools

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    The importance of education and training in the domain of power and energy systems targeting the topics of cyber-physical energy systems/smart grids is discussed in this chapter. State-of-the art laboratory-based and simulation-based tools are presented, aiming to address the new educational needs

    An integrated pan-European research infrastructure for validating smart grid systems

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    A driving force for the realization of a sustainable energy supply in Europe is the integration of distributed, renewable energy resources. Due to their dynamic and stochastic generation behaviour, utilities and network operators are confronted with a more complex operation of the underlying distribution grids. Additionally, due to the higher flexibility on the consumer side through partly controllable loads, ongoing changes of regulatory rules, technology developments, and the liberalization of energy markets, the system’s operation needs adaptation. Sophisticated design approaches together with proper operational concepts and intelligent automation provide the basis to turn the existing power system into an intelligent entity, a so-called smart grid. While reaping the benefits that come along with those intelligent behaviours, it is expected that the system-level testing will play a significantly larger role in the development of future solutions and technologies. Proper validation approaches, concepts, and corresponding tools are partly missing until now. This paper addresses these issues by discussing the progress in the integrated Pan-European research infrastructure project ERIGrid where proper validation methods and tools are currently being developed for validating smart grid systems and solutions.This work is supported by the European Community’s Horizon 2020 Program (H2020/2014-2020) under project “ERIGrid” (Grant Agreement No. 654113). Further information is available at the corresponding website www.erigrid.eu

    A Model Predictive Control Approach to Microgrid Operation Optimization

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    Microgrids are subsystems of the distribution grid, which comprises generation capacities, storage devices, and controllable loads, operating as a single controllable system either connected or isolated from the utility grid. In this paper, we present a study on applying a model predictive control approach to the problem of efficiently optimizing microgrid operations while satisfying a time-varying request and operation constraints. The overall problem is formulated using mixed-integer linear programming (MILP), which can be solved in an efficient way by using commercial solvers without resorting to complex heuristics or decompositions techniques. Then, the MILP formulation leads to significant improvements in solution quality and computational burden. A case study of a microgrid is employed to assess the performance of the online optimization-based control strategy and the simulation results are discussed. The method is applied to an experimental microgrid located in Athens, Greece. The experimental results show the feasibility and the effectiveness of the proposed approach

    Stochastic Model Predictive Control for Economic/Environmental Operation Management of Microgrids: an Experimental Case Study

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    Microgrids are subsystems of the distribution grid which comprises generation capacities, storage devices and flexible loads, operating as a single controllable system either connected or isolated from the utility grid. In this work, microgrid management system is developed in a stochastic framework. It is seen as a constraint-based system that employs forecasts and stochastic techniques to manage microgrid operations. Uncertainties due to fluctuating demand and generation from renewable energy sources are taken into account and a two-stage stochastic programming approach is applied to efficiently optimize microgrid operations while satisfying a time-varying request and operation constraints. At the first stage, before the realizations of the random variables are known, a decision on the microgrid operations has to be made. At the second stage, after random variables outcomes become known, correction actions must be taken, which have a cost. The proposed approach aims at minimizing the expected cost of correction actions. Mathematically, the stochastic optimization problem is stated as a mixed-integer linear programming problem, which is solved in an efficient way by using commercial solvers. The stochastic problem is incorporated in a Model Predictive Control (MPC) scheme to further compensate the uncertainty through the feedback mechanism. A case study of a microgrid is employed to assess the performance of the on-line optimization-based control strategy and the simulation results are discussed. The method is applied to an experimental microgrid: experimental results show the feasibility and the effectiveness of the proposed approach

    Reporting quality of randomized-controlled trials in multiple sclerosis from 2000 to 2015, based on CONSORT statement

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    Background Randomized controlled trials (RCTs) are the best tool to evaluate the effectiveness of clinical interventions. The CONSORT (Consolidated Standards of Reporting Trials) statement is an evidence-based approach to improve the quality of RCTs reporting. Objective To evaluate the reporting quality of published RCTs concerning multiple sclerosis from 2000 to 2015 according to a checklist based on the CONSORT statement. Methods Electronic databases were searched for English-language RCTs involving patients with multiple sclerosis (MS). Trials were considered eligible when participants were randomly assigned to at least two medicinal treatment arms and included patients with MS. Quality of reporting was assessed using a 39–item questionnaire based on the CONSORT checklist. Articles were grouped in three 5-year periods and comparisons were made using descriptive statistics. Results and conclusion The search identified 102 eligible articles for analysis. 20 of the 38 items of the checklist (52.6%) were addressed in 75% or more of the studies. Reporting of more than 75% of CONSORT items (>75% CONSORT compliance) was increased during the three five-year time periods from 2000 to 2015 (p<0.05). Conclusions Quality of reporting in RCTs focusing on multiple sclerosis is showing improvement over time, but still remains unsatisfactory. Further improvement of reporting is necessary to assess the validity of clinical research. © 2016 Elsevier B.V

    Replication of chromosomal loci involved in Parkinson&apos;s disease: A quantitative synthesis of GWAS

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    Introduction: Parkinson&apos;s disease is a neurodegenerative disorder with a complex etiology coming from interactions between genetic and environmental factors. Research on Parkinson&apos;s disease genetics has been an effortful struggle, while new technologies and novel study designs served as indispensable boosters. Until now, 90 loci and 20 disease-causing gene mutations have been identified. In this study we describe a novel non-parametric approach to GWAS meta-analysis and its application in PD genetics. Methods: A literature search was conducted to identify Genome-Wide Association Studies (GWAS) regarding Parkinson&apos;s disease. We applied predefined inclusion criteria and extracted the reported SNPs and their respective position and statistical significance. We divided all chromosomes in approximately equal genetic distance segments called bins and recorded the most significant SNP from each bin and each study and ranked them in terms of their p-value. Ranks from each bin were summed, averaged and added in a heterogeneity-based analysis using the METRADISC-XL software. Weighted and unweighted analysis was performed. Results: Five-hundred and forty-three SNPs and their respective p-values from 15 studies were matched in their corresponding bins. The METRADISC-XL analysis resulted in 7 bins with a significant p-value. A bin on chromosome 4 where the SNCA gene is located found with genome-wide significant association with Parkinson&apos;s Disease. Conclusion: This is the first time a non-parametric method is applied in GWAS meta-analysis. The results add some insight on the overall understanding of Parkinson&apos;s disease genetics and serve as a first step of further convergent analysis with Genome-wide linkage studies. © 202

    Reporting quality of randomized-controlled trials in multiple sclerosis from 2000 to 2015, based on CONSORT statement

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    Background Randomized controlled trials (RCTs) are the best tool to evaluate the effectiveness of clinical interventions. The CONSORT (Consolidated Standards of Reporting Trials) statement is an evidence-based approach to improve the quality of RCTs reporting. Objective To evaluate the reporting quality of published RCTs concerning multiple sclerosis from 2000 to 2015 according to a checklist based on the CONSORT statement. Methods Electronic databases were searched for English-language RCTs involving patients with multiple sclerosis (MS). Trials were considered eligible when participants were randomly assigned to at least two medicinal treatment arms and included patients with MS. Quality of reporting was assessed using a 39–item questionnaire based on the CONSORT checklist. Articles were grouped in three 5-year periods and comparisons were made using descriptive statistics. Results and conclusion The search identified 102 eligible articles for analysis. 20 of the 38 items of the checklist (52.6%) were addressed in 75% or more of the studies. Reporting of more than 75% of CONSORT items (&gt;75% CONSORT compliance) was increased during the three five-year time periods from 2000 to 2015 (p&lt;0.05). Conclusions Quality of reporting in RCTs focusing on multiple sclerosis is showing improvement over time, but still remains unsatisfactory. Further improvement of reporting is necessary to assess the validity of clinical research. © 2016 Elsevier B.V

    Replication of chromosomal loci involved in Parkinson's disease: A quantitative synthesis of GWAS

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    Introduction: Parkinson's disease is a neurodegenerative disorder with a complex etiology coming from interactions between genetic and environmental factors. Research on Parkinson's disease genetics has been an effortful struggle, while new technologies and novel study designs served as indispensable boosters. Until now, 90 loci and 20 disease-causing gene mutations have been identified. In this study we describe a novel non-parametric approach to GWAS meta-analysis and its application in PD genetics. Methods: A literature search was conducted to identify Genome-Wide Association Studies (GWAS) regarding Parkinson's disease. We applied predefined inclusion criteria and extracted the reported SNPs and their respective position and statistical significance. We divided all chromosomes in approximately equal genetic distance segments called bins and recorded the most significant SNP from each bin and each study and ranked them in terms of their p-value. Ranks from each bin were summed, averaged and added in a heterogeneity-based analysis using the METRADISC-XL software. Weighted and unweighted analysis was performed. Results: Five-hundred and forty-three SNPs and their respective p-values from 15 studies were matched in their corresponding bins. The METRADISC-XL analysis resulted in 7 bins with a significant p-value. A bin on chromosome 4 where the SNCA gene is located found with genome-wide significant association with Parkinson's Disease. Conclusion: This is the first time a non-parametric method is applied in GWAS meta-analysis. The results add some insight on the overall understanding of Parkinson's disease genetics and serve as a first step of further convergent analysis with Genome-wide linkage studies. © 202

    Reporting quality of randomized controlled trials in restless legs syndrome based on the CONSORT statement

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    Background: Randomized controlled trials (RCTs) are the cornerstone of modern medical research, and their reporting may not always be optimal. The Consolidated Standards of Reporting Trials (CONSORT) statement is an evidence-based means to improve the quality of RCTs’ reporting by providing a checklist of recommended items. The aim of this study was to assess the reporting quality of published RCTs on the restless legs syndrome (RLS), based on a checklist arising from the CONSORT statement. Methods: Medical electronic databases were searched for RCTs involving patients with RLS. Inclusion criteria were follows: articles must have been published in English and RLS patients must have been randomized into a minimum of two treatment cohorts of different medicinal orientations. CONSORT-recommended items were marked as “reported” or “not reported,” and an overall CONSORT compliance metric was calculated. Comparisons among different time periods, CONSORT-endorsing and non-endorsing, and different levels of impact factor journals were made. Results: Fifty-four eligible trials, published in 21 different scientific journals, were found. The average CONSORT compliance score was 56.6% (23.68–84.21%). CONSORT-endorsing journals had a mean CONSORT compliance of 58.47%, whereas non-endorsing journals had a mean CONSORT compliance of 50.4%. The median CONSORT compliance for articles published in low- (IF7) journals was 52.63, 56.57, and 59.21%, respectively. Only 14 of the 38 CONSORT items (36.8%) were reported in >75% of the articles. Discussion: This study shows that the reporting of RLS-related RCTs is suboptimal, regardless of the time period, the quality of the publishing journal, and the endorsing or non-endorsing of the CONSORT statement. © 2019 Rikos et al. All rights reserved
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