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Journal of Computer and Communications 2020年第9期8卷 100-108页

作者： Conrad K. Simatimbe smart charles lubobya Department of Electrical and Electronic Engineering School of Engineering The University of Zambia Lusaka Zambia

This paper evaluates the performance of Internet Protocol Security (IPSec) based Multiprotocol Label Switching (MPLS) virtual private network (VPN) in a small to medium sized organization. The demand for security in data networks has been increasing owing to the high cyber attacks and potential risks associated with networks spread over distant geographical locations. The MPLS networks ride on the public network backbone that is porous and highly susceptible to attacks and so the need for reliable security mechanisms to be part of the deployment plan. The evaluation criteria concentrated on Voice over Internet Protocol (VoIP) and Video conferencing with keen interest in jitter, end to end delivery and general data flow. This study used both structured questionnaire and observation methods. The structured questionnaire was administered to a group of 70 VPN users in a company. This provided the study with precise responses. The observation method was used in data simulations using OPNET Version 14.5 Simulation software. The results show that the IPSec features increase the size of data packets by approximately 9.98% translating into approximately 90.02% effectiveness. The tests showed that the performance metrics are all well within the recommended standards. The IPSec Based MPLS Virtual private network is more stable and secure than one without IPSec.

关键词： Multiprotocol Label Switching Internet Protocol Security Virtual Private Network Video Conferencing Voice over Internet Protocol Jitter End to End Delay

Fuzzy Logic Controller-based Synchronverter in Grid-connected Solar Power System with Adaptive Damping Factor

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Chinese Journal of Electrical Engineering 2021年第2期7卷 37-49页

作者： Kah Yung Yap Chee Ming Beh charles R.Sarimuthu Department of Electrical and Computer Systems Engineering(ECSE) School of EngineeringMonash University MalaysiaSubang Jaya 47500Malaysia

In recent years,renewable energy sources,specifically solar power systems,have developed rapidly owing to their technological maturity and cost ***,its grid integration deteriorates frequency stability because of insufficient rotating masses and inertial ***,a synchronverter,which is an inverter that mimics the operation of a synchronous generator,is crucial to interface solar power in a power *** stabilizes the power grid by emulating a virtual ***,a conventional proportional-integral(PI)-based synchronverter is not equipped with an adaptive damping factor(Dp)or a digitalized smart controller to manage fast-responding solar ***,a novel fuzzy logic controller(FLC)framework is proposed such that the synchronverter can operate in a grid-connected solar power *** this study,Dp is controlled in real time using an FLC to achieve balance between speed and stability for frequency error correction based on frequency *** of four case studies performed in Matlab/Simulink show that the proposed FLC-based synchronverter can stabilize the grid frequency by reducing the frequency deviation by at least 0.2 Hz(0.4%),as compared with the conventional PI-based synchronverter.

关键词： Fuzzy logic controller(FLC) synchronverter renewable energy system(RES) grid stability solar power system

Narrowband PLC Channel Workbench to Emulate Transmission in smart Grid

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Journal of Control Science and Engineering 2016年第2期4卷 51-60页

作者： Ismail Aouichak Anouar Achouri Jean-charles Le Bunetel Yves Raingeaud Research Group on Materials Microelectronics and Acoustic Nanotechnology University of Tours Tours 37200 France

A real-time workbench able to reproduce the same behavior as an indoor network is in order. Such a tool will help researchers and industrials extend the smart grid technology indoors and have a better acknowledgment of smart Grid systems interoperability. In order to develop such a tool many approaches should be studied to choose the most suitable one by comparing the models and the technologies. The considered hardware are the embedded systems and the selected approach is the statistical one. It appears that the FIR filter is the most pertinent approach.

关键词： Embedded systems emulator power line transfer function modeling FIR (finite impulse response) filters narrowband PLC (power line communication)

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神经环路设计的普遍原则

生命科学 2008年第5期20卷 725-728页

作者： STEVENS charles F 美国Salk生物学研究所分子神经生物学实验室

该文介绍一种可以不断升级神经环路的规模的设计原则。作者将单个视网膜神经节细胞的树突区域定义为类似于数码相机CCD上的一个"像素"。决定这个像素的大小(即树突区域所占的大小)存在两种相互竞争的因素:为得到最高的分辨率,像素应越... 详细信息

该文介绍一种可以不断升级神经环路的规模的设计原则。作者将单个视网膜神经节细胞的树突区域定义为类似于数码相机CCD上的一个"像素"。决定这个像素的大小(即树突区域所占的大小)存在两种相互竞争的因素:为得到最高的分辨率,像素应越小越好;另一方面,像素越大越利于平均化输入信号,以得到信噪比精确度最高的光强度值递呈给大脑。作者列举了三种可能的策略来阐释如何设计一个视网膜像素大小,并且为进化中实际选择的策略提供了证据。

关键词：神经环路视网膜神经节细胞像素

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模糊建筑 2002瑞士世博会,瑞士

世界建筑导报 2021年第6期36卷 120-121页

作者： charles Renfro Reto Geiser David Huang Karin Ocker Andreas Quadenau Deane Simpson Lyn Rice 无不详 DS+R建筑事务所

模糊建筑整体水雾弥漫,是自然与人类的合力之作。纳沙泰尔湖(Lake Neuchatel)湖水经水泵抽出并过滤后,再由3.5万个高压喷嘴喷射成绵绵细雾。智能天气系统随时检测温度、湿度、风速、风向等不断变化的气象条件,调节各个区域的水压压力。... 详细信息

模糊建筑整体水雾弥漫,是自然与人类的合力之作。纳沙泰尔湖(Lake Neuchatel)湖水经水泵抽出并过滤后,再由3.5万个高压喷嘴喷射成绵绵细雾。智能天气系统随时检测温度、湿度、风速、风向等不断变化的气象条件,调节各个区域的水压压力。一踏入"模糊建筑",眼前雾气蔼蔼,耳旁淅淅沥沥,视觉与听觉也会变得模糊起来。沉浸式环境通过越发精湛的科学技术追求高清高保真的视觉体验。而"模糊建筑"逆道而行,极尽朦胧之所能。该展馆设计尝试摆脱周边环境的束缚。游客置身其中,活动无拘无束,目之所及似有似无,宛如梦幻。层层阶梯在水雾中若隐若现,通向蓝天。公众踏着阶梯,可登上天使甲板(Angel Deck)。这座建筑选址湖边。水不仅是其主要材料,也令游客置身其中,宛若步入瑶池,仿佛畅饮琼浆玉液。艺术大师克里斯蒂安·马克雷(Christian Marclay)还采用轻质张拉整体结构,为其内部打造了沉浸式的声学环境。该结构由四根立柱支撑,75英尺高、300英尺宽、200英尺深。

关键词：张拉整体结构高压喷嘴检测温度声学环境世博会置身其中沉浸式建筑选址

Room-temperature multiple ligands-tailored SnO_(2) quantum dots endow in situ dual-interface binding for upscaling efficient perovskite photovoltaics with high V_(OC)

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Light(Science & Applications) 2021年第12期10卷 2467-2481页

作者： Zhiwei Ren Kuan Liu Hanlin Hu Xuyun Guo Yajun Gao Patrick W.K.Fong Qiong Liang Hua Tang Jiaming Huang Hengkai Zhang Minchao Qin Li Cui Hrisheekesh Thachoth Chandran Dong Shen Ming-Fai Lo Annie Ng charles Surya Minhua Shao Chun-Sing Lee Xinhui Lu Frédéric Laquai Ye Zhu Gang Li Department of Electronic and Information Engineering Research Institute for Smart Energy(RISE)Guangdong-Hong Kong-Macao(GHM)Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and DevicesThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of Electrical and Computer Engineering Nazarbayev UniversityNur-SultanKazakhstan The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057China Hoffmann Institute of Advanced Materials Shenzhen Polytechnic7098 Liuxian BoulevardShenzhen 518055China Department of Applied Physics The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina King Abdullah University of Science and Technology(KAUST) KAUST Solar Center(KSC)Physical Sciences and Engineering Division(PSE)Material Science and Engineering Program(MSE)Thuwal 23955-6900Kingdom of Saudi Arabia Department of Physics The Chinese University of Hong KongShatin 999077 Hong KongChina Center of Super-Diamond and Advanced Films(COSDAF) Department of ChemistryCity University of Hong KongHong KongChina

The benchmark tin oxide(SnO_(2))electron transporting layers(ETLs)have enabled remarkable progress in planar perovskite solar cell(PSCs).However,the energy loss is still a challenge due to the lack of“hidden interface”*** report a novel ligand-tailored ultrafine SnO_(2) quantum dots(QDs)via a facile rapid room temperature ***,the ligand-tailored SnO_(2) QDs ETL with multi-functional terminal groups in situ refines the buried interfaces with both the perovskite and transparent electrode via enhanced interface binding and perovskite *** novel ETLs induce synergistic effects of physical and chemical interfacial modulation and preferred perovskite crystallization-directing,delivering reduced interface defects,suppressed non-radiative recombination and elongated charge carrier *** conversion efficiency(PCE)of 23.02%(0.04 cm^(2))and 21.6%(0.98 cm^(2),V_(OC) loss:0.336 V)have been achieved for the blade-coated PSCs(1.54 eV E_(g))with our new ETLs,representing a record for SnO_(2) based blade-coated ***,a substantially enhanced PCE(V_(OC))from 20.4%(1.15 V)to 22.8%(1.24 V,90 mV higher V_(OC),0.04 cm^(2) device)in the blade-coated 1.61 eV PSCs system,via replacing the benchmark commercial colloidal SnO_(2) with our new ETLs.

关键词： perovskite interface quantum

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走向“新的”阳光都市主义

风景园林 2020年第5期27卷 98-104页

作者： [美]查尔斯·瓦尔德海姆邬峻(译) 张博雅(校) 哈佛大学设计研究生院荷兰阿纳雄智慧城市基金会哈佛大学哈佛大学设计研究生院城市化办公室

关于日照朝向和城市形态的话题既是永恒的,又是应景的。"生态都市主义"的论述和实践将我们的注意力吸引到与水文网络和生态功能相关的主题。而阳光都市主义提议通过回到日照性能这一话题来修订和扩展当下生态都市主义的议程。在最近的... 详细信息

关于日照朝向和城市形态的话题既是永恒的,又是应景的。"生态都市主义"的论述和实践将我们的注意力吸引到与水文网络和生态功能相关的主题。而阳光都市主义提议通过回到日照性能这一话题来修订和扩展当下生态都市主义的议程。在最近的项目中,许多领先的建筑师和城市主义者根据日照朝向提出了城市秩序的新形式。在许多此类项目中,设计师将城市形态与复杂而矛盾的日照性能经济联系在一起。日照朝向和社会秩序、公共卫生和政治经济学等主题是许多现代规划师及其项目面临的基本问题。随着现代规划的崩溃,基于纬度和日照公平性的城市秩序单一模型已被受市场驱动的城市化新自由主义模型所取代。笔者重返城市秩序这一古老议题,并通过一系列规划政策和先例展示其潜力。不论经纬度如何,在许多文化中,晒太阳被公认为是一项古老而不可侵犯的权利。笔者重新考虑了与社会公平相关的日照获取,继而考察了源于资本积累的建筑形态与基于环境共识的采光需求之间的矛盾关系。20世纪70年代的能源危机和经济冲击引发了建筑和城市主义的一系列实验性的、反文化的实践。当前的环境危机包括对于零碳政策的应对,并将其操作规模推广到了城市形态的尺度。拉尔夫·诺尔斯(Ralph Knowles)的"日照包络体"(solar envelope)概念提出了一种设计工具,该工具预示了当代对设计参数化和关系化建模的兴趣。包络体提供了一种预测形态,从而将城市形态与日照性能相互关联。过去10年的技术发展带来了意想不到的精确度和反馈程度,也许能为这一有着半个世纪历史的创意注入新的可能。本研究从概念及预测角度出发,分析了当代计算机几何模型对该设计模式所带来的变革。

关键词：阳光都市主义日照性能日照包络体生态都市主义关系化城市建模