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通过运行数据的性能分析评估Mewis导流罩的效率

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Journal of Marine Science and Application 2022年第2期21卷 144-158页

作者： Anastasios Zalachoris nikos Themelis School of Naval Architecture and Marine Engineering National Technical University of Athens 9 Iroon Polytechneiou15780AthensGreece

Τhe efficiency of a Mewis propeller duct by the analysis of ship operational data is examined.The analysis employs data collected with high frequency for a three-year period for two siter vessels,one of them fitted with a Mewis type duct.Our approach to the problem of identifying improvements in the operational performance of the ship equipped with the duct is two-fold.Firstly,we proceed with the calculation of appropriate Key Performance Indicators to monitor vessels performance in time for different operational periods and loading conditions.An extensive pre-processing stage is necessary to prepare a dataset free from datapoints that could impair the analysis,such as outliers,as well as the appropriate preparations for a meaningful KPI calculation.The second approach concerns the development of multiple linear regression problem for the prediction of main engine fuel oil consumption based on operational and weather parameters,such as ship’s speed,mean draft,trim,rudder angle and the wind speed.The aim is to quantify reductions due to the Mewis duct for several scenarios.Key results of the studies reveal a contribution of the Mewis duct mainly in laden condition,for lower speed range and in the long-term period after dry-docking.

关键词： Performance monitoring Energy saving device Regression models Data processing Mewis duct

Guest Editorial: Special Section on Battery Energy Storage Systems for Net-zero Power Systems and Markets

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JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY 2024年第2期12卷 321-322页

作者： Mancarella, Pierluigi Hatziargyriou, nikos Kang, Chongqing Univ Melbourne Melbourne Australia Univ Manchester Manchester England Natl Tech Univ Athens NTUA Athens Greece Tsinghua Univ Beijing Peoples R China

Battery energy storage technologies have witnessed both dramatic cost reduction and technical evolution in recent years. This is leading to widespread deployment of battery energy storage systems (BESSs) worldwide, particularly to support operation of power grids with already deep penetration of renewables. Considering the development of new battery technologies with different power-to-energy ratios and for various engineering applications, BESSs could play a strategic role towards a net-zero energy future. New opportunities are emerging for BESSs to participate in several markets, provide different grid services, and perform "value stacking", eventually allowing development of new business cases and improved BESS economics. BESS configurations that are "behind the meter", "in front of the meter", hybrid plants co-located with renewables, and so forth, are only some of the exciting propositions that are being seen in different countries and at different scales, from highly distributed (virtual power plants), to neighbourhood-level (community batteries), to utility scale.

关键词： Meters Costs Battery energy storage system Special issues and sections Net zero Stacking Virtual power plants

pH-responsive AIE-active Polyethylene-based Block Copolymers

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Chinese Journal of Polymer Science 2019年第9期37卷 930-935页

作者： Yu Jiang nikos Hadjichristidis Physical Sciences and Engineering Division KAUST Catalysis Center Polymer Synthesis Laboratory King Abdullah University of Science and Technology (KAUST)

A novel synthetic strategy towards pH-responsive aggregation-induced emission (AIE)-active tetraphenylethene (TPE)- functionalized polyethylene-based block copolymers is presented. Tris(3-(4-(l,2,2-triphenylvinyl)phenoxy)propyl)borane was used to initiate the polyhomologation of dimethylsulfoxonium methylide to afford well-defined a-TPE-ω-OH linear polyethylenes (PE). The terminal hydroxyl groups were transformed to atom transfer radical polymerization (ATRP) initiating sites by esterification with bromoisobutyryl bromide, followed by polymerization of rert-butyl acrylate (tBA) to provide TPE-PE-b-PtBA block copolymers. After hydrolysis of the rBu group to COOH group, the corresponding pH-responsive TPE-PE-b-PAA block copolymers were obtained. All synthesized block copolymers revealed AIE behavior either in solution or bulk. Due to the pH-responsivity of PAA chains, the aggregation state at different pH and consequently the fluorescence intensity changed. Also, the synthesized block copolymers exhibited ion-specificity fluorescence properties.

关键词： Polyhomologation ATRP Polyethylene-b-poly(acrylic acid) AIE pH-responsivity Ion-specificity

Optical RAM and integrated optical memories:a survey

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Light(Science & Applications) 2020年第1期9卷 1117-1132页

作者： Theoni Alexoudi George Theodore Kanellos nikos Pleros Department of Informatics Aristotle University of ThessalonikiThessalonikiGreece Department of Electrical&Electronic Engineering University of BristolBristolUK

The remarkable achievements in the area of integrated optical memories and optical random access memories(RAMs)together with the rapid adoption of optical interconnects in the Datacom and Computercom industries introduce a new perspective for information storage directly in the optical domain,enabling fast access times,increased bandwidth and transparent cooperation with optical interconnect lines.This article reviews state-of-the-art integrated optical memory technologies and optical RAM cell demonstrations describing the physical mechanisms of several key devices along with their performance metrics in terms of their energy,speed and footprint.Novel applications are outlined,concluding with the scaling challenges to be addressed toward allowing light to serve as both a datacarrying and data-storage medium.

关键词： RAM transparent scaling

Taking central nervous system regenerative therapies to the clinic: curing rodents versus nonhuman primates versus humans

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Neural Regeneration Research 2020年第3期15卷 425-437页

作者： Magdalini Tsintou Kyriakos Dalamagkas nikos Makris Departments of Psychiatry and Neurology Services Center for Neural Systems InvestigationsCenter for Morphometric AnalysisAthinoula A.Martinos Center for Biomedical ImagingMassachusetts General HospitalHarvard Medical SchoolBostonMAUSA Department of Psychiatry Psychiatry Neuroimaging LaboratoryBrigham and Women’s HospitalHarvard Medical SchoolBostonMAUSA University College of London Division of Surgery&Interventional Science Center for Nanotechnology&Regenerative MedicineUniversity College LondonLondonUK Department of Physical Medicine and Rehabilitation The University of Texas Health Science Center at HoustonHoustonTXUSA The Institute for Rehabilitation and Research Memorial Hermann Research Center The Institute for Rehabilitation and Research Memorial Hermann HospitalHoustonTXUSA Department of Anatomy&Neurobiology Boston University School of MedicineBostonMAUSA

The central nervous system is known to have limited regenerative capacity.Not only does this halt the human body’s reparative processes after central nervous system lesions,but it also impedes the establishment of effective and safe therapeutic options for such patients.Despite the high prevalence of stroke and spinal cord injury in the general population,these conditions remain incurable and place a heavy burden on patients’families and on society more broadly.Neuroregeneration and neural engineering are diverse biomedical fields that attempt reparative treatments,utilizing stem cells-based strategies,biologically active molecules,nanotechnology,exosomes and highly tunable biodegradable systems(e.g.,certain hydrogels).Although there are studies demonstrating promising preclinical results,safe clinical translation has not yet been accomplished.A key gap in clinical translation is the absence of an ideal animal or ex vivo model that can perfectly simulate the human microenvironment,and also correspond to all the complex pathophysiological and neuroanatomical factors that affect functional outcomes in humans after central nervous system injury.Such an ideal model does not currently exist,but it seems that the nonhuman primate model is uniquely qualified for this role,given its close resemblance to humans.This review considers some regenerative therapies for central nervous system repair that hold promise for future clinical translation.In addition,it attempts to uncover some of the main reasons why clinical translation might fail without the implementation of nonhuman primate models in the research pipeline.

关键词： animal models central nervous system regeneration clinical translation exosomes hydrogels neural tissue engineering nonhuman primates spinal cord injury stem cells stroke

Towards an Internet-like Power Grid

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Journal of Modern Power Systems and Clean Energy 2022年第1期10卷 1-11页

作者： Iasonas Kouveliotis-Lysikatos nikos Hatziargyriou Yanli Liu Felix Wu Department of Electrical Engineering and Computer Science KTH-Royal Institute of TechnologyTeknikringen 3310040StockholmSweden School of Electrical and Computer Engineering National Technical University of Athens15773 AthensGreece School of Electrical and Information Engineering Tianjin UniversityTianjin300072China Department of Electrical and Electronic Engineering The University of Hong KongHong KongChina Department of Electrical Engineering and Computer Sciences University of CaliforniaBerkeleyCA 94720USA

The great challenges faced by modern power systems require a fresh look at the conventional operation paradigm. The significant challenges faced by modern power systems require an innovative method for the conventional operation paradigm. We claim that the decarbonization of the power grid and extensive electrification of numerous sectors of human activity can only be fostered by a self-adaptable and smart power grid that manifests similar qualities to those of the Internet. The Internet is constructed on a layered architecture that facilitates technology innovations and its intelligence is distributed throughout a hierarchy of networks. In this paper, the fundamental differences between the network data flows and power flows are examined, and the basic requirements for an innovative operation paradigm are highlighted. The current power grid is operated in a highly inflexible, centralized manner to meet increased security goals. A new highly flexible, distributed architecture can be realized by distributing the operation responsibility in smaller areas or even in grid components that can make autonomous decisions. The characteristics of such a power grid are presented, and the key features and advances for the on-going transition to a sustainable power system are identified. Finally, a case study on distributed voltage control is presented and discussed.

关键词： Smart grid Internet distributed intelligence decentralized architecture

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种植体与基台连接的微观形态学观察

上海口腔医学 2018年第4期27卷 360-364页

作者：李晓娜 nikos Mattheos 大连市口腔医院特诊科辽宁大连116021 香港大学牙医学院口腔修复科香港999077

目的 :对种植体与原厂基台及第三方基台连接组件形态学上的微观特征进行观察,探讨形态差异与潜在并发症之间可能的关系。方法:3种基台(1个原厂装,2个来自第三方)在规定扭矩下装配到Straumann RN种植体上,种植体基台连接单元经过一系列... 详细信息

目的 :对种植体与原厂基台及第三方基台连接组件形态学上的微观特征进行观察,探讨形态差异与潜在并发症之间可能的关系。方法:3种基台(1个原厂装,2个来自第三方)在规定扭矩下装配到Straumann RN种植体上,种植体基台连接单元经过一系列包埋等程序后切割形成剖面,对剖面进行打磨,对完成的试件进行扫描电镜观察。采用图像测量软件(Image J)对获得的图片进行校准测量,比较三者之间在接触长度及接触性质之间的差异,尤其是3个重要部位即肩部、内连接及螺纹处的差异。结果:3个连接单元的所有被研究的接触面之间均存在一定的尺寸差异。3个单元中,种植体外肩部的紧密接触相似,但第三方基台内部连接的啮合,特别是抗旋转单元严重欠缺,其中1个第三方基台的螺丝啮合不良。结论:与原装基台对比,第三方基台呈现出关键性的形态差异,横断面的几何学差异导致总体接触面积有很大不同。无论从质量上,还是数量上这种差异对修复体的长期稳定性均有可能产生严重影响。

关键词：种植体基台连接微观形态学

Intelligent Voltage Control Method in Active Distribution Networks Based on Averaged Weighted Double Deep Q-network Algorithm

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Journal of Modern Power Systems and Clean Energy 2023年第1期11卷 132-143页

作者： Yangyang Wang Meiqin Mao Liuchen Chang nikos D.Hatziargyriou Research Center for Photovoltaic System Engineering Ministry of EducationSchool of Electrical Engineering and AutomationHefei University of TechnologyHefei 230009China University of New Brunswick FrederictonNB E3B 5A3Canada National Technical University of Athens Athens 15780Greece IEEE

High penetration of distributed renewable energy sources and electric vehicles(EVs)makes future active distribution network(ADN)highly variable.These characteristics put great challenges to traditional voltage control methods.Voltage control based on the deep Q-network(DQN)algorithm offers a potential solution to this problem because it possesses humanlevel control performance.However,the traditional DQN methods may produce overestimation of action reward values,resulting in degradation of obtained solutions.In this paper,an intelligent voltage control method based on averaged weighted double deep Q-network(AWDDQN)algorithm is proposed to overcome the shortcomings of overestimation of action reward values in DQN algorithm and underestimation of action reward values in double deep Q-network(DDQN)algorithm.Using the proposed method,the voltage control objective is incorporated into the designed action reward values and normalized to form a Markov decision process(MDP)model which is solved by the AWDDQN algorithm.The designed AWDDQN-based intelligent voltage control agent is trained offline and used as online intelligent dynamic voltage regulator for the ADN.The proposed voltage control method is validated using the IEEE 33-bus and 123-bus systems containing renewable energy sources and EVs,and compared with the DQN and DDQN algorithms based methods,and traditional mixed-integer nonlinear program based methods.The simulation results show that the proposed method has better convergence and less voltage volatility than the other ones.

关键词： Averaged weighted double deep Q-network(AWDDQN) deep Q learning active distribution network(ADN) voltage control electrical vehicle(EV)

基于暂态分析和系统辨识的光伏并网逆变器建模

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电工技术学报 2021年第10期36卷 2061-2071页

作者：翁公羽茆美琴张榴晨 nikos Hatziargyriou 合肥工业大学教育部光伏系统工程研究中心合肥230009 加拿大新布伦瑞克大学弗雷德里克顿E3B5A3 希腊雅典国立理工大学电气与计算机工程学院雅典15780

建立并网光伏发电系统的模型是研究其与电网交互过程的基础。光伏系统的暂态特性不仅受天气情况、电网工况等环境因素的影响,还取决于商用逆变器的内部结构以及控制策略,然而它们并不对外公开,这给系统的分析带来了困难。为了解决这个问... 详细信息

建立并网光伏发电系统的模型是研究其与电网交互过程的基础。光伏系统的暂态特性不仅受天气情况、电网工况等环境因素的影响,还取决于商用逆变器的内部结构以及控制策略,然而它们并不对外公开,这给系统的分析带来了困难。为了解决这个问题,该文提出一种基于暂态分析和系统辨识的光伏并网逆变器通用建模方法。将光伏逆变器视作内部结构以及控制算法未知的黑箱,通过先后施加扰动和测取响应并结合系统辨识的方法来建立其模型。以一个3kW的商用光伏逆变器为研究对象,搭建硬件在环实验系统来研究并验证这一建模方法。结果显示,在多种扰动对应的暂态过程中,模型的输出均准确地拟合了逆变器的实际输出,证明了这一建模方法的有效性。

关键词：光伏逆变器建模系统辨识传递函数功率硬件在环