检索结果-南通市图书馆

Planning of distributed renewable energy systems under uncertainty based on statistical machine learning

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Protection and control of Modern Power Systems 2022年第1期7卷 619-645页

作者： Xueqian Fu Xianping Wu Chunyu Zhang Shaoqian Fan Nian Liu College of Information and Electrical Engineering China Agricultural University100083 BeijingChina Beijing Engineering and technology research Center for Internet of Things in Agriculture BeijingPeople’s Republic of China State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources North China Electric Power University102206 BeijingChina

The development of distributed renewable energy,such as photovoltaic power and wind power generation,makes the energy system cleaner,and is of great significance in reducing carbon ***,weather can affect distributed renewable energy power generation,and the uncertainty of output brings challenges to uncertainty planning for distributed renewable *** systems with high penetration of distributed renewable energy involve the high-dimensional,nonlinear dynamics of large-scale complex systems,and the optimal solution of the uncertainty model is a difficult *** the perspective of statistical machine learning,the theory of planning of distributed renewable energy systems under uncertainty is reviewed and some key technologies are put forward for applying advanced artificial intelligence to distributed renewable power uncertainty planning.

关键词： Distributed renewable energy systems Statistical machine learning Uncertainty planning Renewable energy network

controls of seed quantity and quality on seedling recruitment of smith fir along altitudinal gradient in southeastern Tibetan Plateau

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2016年第5期13卷 811-821页

作者： WANG Jing-sheng FENG Ji-guang CHEN Bao-xiong SHI Pei-li ZHANG Jun-long FANG Jiang-ping WANG Zhi-kai YAO Shuai-chen DING Lu-bin Lhasa Plateau Ecosystem research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China School of Environment and Natural Resources Renmin University of ChinaBeiing 100872China Rural Energy&Environment Agency Ministry of Agriculture of the People's Republic of ChinaBeijing 100125China National Center for Climate Change Strategy and International Cooperation Beijing 100038China TibetAgricultural andAnimal Husbandry College Tibet Linzhi 860000China

Alpine treeline ecotones are harsh environment for tree establishment due to low temperature. Tree establishment at treelines requires favorable climate, suitable microsites, and viable seeds. But most researches have been addressed treeline microclimate and its effects on tree regeneration, the knowledge of seed quantity and quality and its controls on seedling recruitment were limited. We measured seed rain, soil seed bank, seed germination rate and seedling recruitment in natural forests in combination with seed transplanting manipulation to evaluate the controls of seed quantity and quality on seedling recruitment of Abies georgei var. smithii （smith fir） along altitudinal gradient, with focus on treeline ecotone in the Sygera Mountains, southeastern Tibetan Plateau. Both seed quantity and seed quality of smith fir decreased with increasing altitude and was thereby associated with decline in seed germination rate. Seed quantity and seedling recruitment were better in north-facing slope than in south slope. The treeline ecotone above 42oo m appeared as the threshold altitude to sharply decrease seed quality and seedling recruitment. The emergence and overwintering rates of transplanting seeds from 3600-38oo m also went down remarkably above 4200 m at north-facing slope. It also underpins the fact that treeline ecotone is the bottleneck of seedling recruitment. Our results suggest that seed quantity and quality are the principal limitation of treeline upward advance. This study also provides evidence to support stable treeline position in southeastern Tibetan Plateau.

关键词： Abies georgei var. smithii Treeline Seed rain Soil seed bank Seed quality Seedling recruitment

Multi-spacecraft Intelligent Orbit Phasing control Considering Collision Avoidance

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing university of Aeronautics and Astronautics 2022年第4期39卷 379-388页

作者： LI Jian ZHANG Gang research Center of Satellite technology Harbin Institute of TechnologyHarbin 150080P.R.China

This paper proposes an intelligent low-thrust orbit phasing control method for multiple spacecraft by simultaneously considering fuel optimization and collision avoidance. Firstly,the minimum-fuel orbit phasing control database is generated by the indirect method associated with the homotopy technique. Then,a deep network representing the minimum-fuel solution is trained. To avoid collision for multiple spacecraft,an artificial potential function is introduced in the collision-avoidance controller. Finally,an intelligent orbit phasing control method by combining the minimum-fuel neural network controller and the collision-avoidance controller is proposed. Numerical results show that the proposed intelligent orbit phasing control is valid for the multi-satellite constellation initialization without collision.

关键词： orbit phasing control low thrust deep neural networks collision avoidance

An Improved Reactive Power control Strategy for Overvoltage Fluctuation of Distribution network with High Penetration of PVs

在线全文

学校读者我要写书评

暂无评论

An Improved Reactive Power Control Strategy for Overvoltage ...

A New Selective Neural network Ensemble Method Based on Error Vectorization and Its Application in High-density Polyethylene (HDPE) Cascade Reaction Process

第36届中国控制会议

作者： Jiayan Liu Yong Li Fang Liu Miao Miao Yijia Cao College of Electrical and Information Engineering Hunan University College of Information Science and Engineering Central South University

ISBN: (纸本)9781538629185

In distribution network,with the installed of photovoltaic（PV）,bought many *** of the most concerned problems is the overvoltage in the terminal bus of distribution *** is caused by the reverse power flow which brought out by the increase of the PV sources *** this paper,an improved PQ-Q（V） control strategy is proposed to alleviate such *** economic performance and the efficiency are considered in this prosed *** photovoltaic grid-connected inverter is controlled to compensate the overvoltage or under voltage by compensating the inductive and capacitive reactive power to ensure voltage are within rated *** performance is compared with a traditional control *** this basis,the influence of the method on the network is investigated,which have been found that the value of tune parameter will affect the regulate ability and the system *** this paper,the 13-bus IEEE network is used in the simulation of DIgSILENT software.

关键词： Low voltage distribution network photovoltaic permeability photovoltaic power management voltage rise stability

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2012年第6期20卷 1142-1147页

作者：朱群雄赵乃伟徐圆 College of Information Science & technology Beijing University of Chemical Technology

Chemical processes are complex, for which traditional neural network models usually can not lead to satisfactory accuracy. Selective neural network ensemble is an effective way to enhance the generalization accuracy of networks, but there are some problems, e.g., lacking of unified definition of diversity among component neural networks and difficult to improve the accuracy by selecting if the diversities of available networks are small. In this study, the output errors of networks are vectorized, the diversity of networks is defined based on the error vectors, and the size of ensemble is analyzed. Then an error vectorization based selective neural network ensemble (EVSNE) is proposed, in which the error vector of each network can offset that of the other networks by training the component networks orderly. Thus the component networks have large diversity. Experiments and comparisons over standard data sets and actual chemical process data set for production of high-density polyethylene demonstrate that EVSNE performs better in generalization ability.

关键词： high-density polyethylene modeling selective neural network ensemble diversity definition error vectorization

具有异质结构的多功能氧化石墨烯改性纳米纤维膜(ZnS-CoS@GO@CNFs)用于长期稳定的钾离子储存

在线全文

学校读者我要写书评

暂无评论

中国科学:材料科学(英文版) 2023年第8期66卷 3093-3103页

作者：楼愉康李鹏超何宏程周世强蔡勇陈宝辉张明 Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics&Devices School of Physics and ElectronicsHunan UniversityChangsha 410082China Changsha Semiconductor technology and Application Innovation research Institute College of Semiconductors(College of Integrated Circuits)Hunan UniversityChangsha 410082China College of Science Henan University of TechnologyZhengzhou 450001China State Key Laboratory of Disaster Prevention&Reduction for Power Grid Transmission and Distribution Equipment(Hunan Electric Power Corporation Disaster Prevention and Reduction Center) Changsha 410007China Engineering research Center of advanced Semiconductor technology and Application of Ministry of Education&Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education College of Semiconductors(College of Integrated Circuits)Hunan UniversityChangsha 410082China

过渡金属硫化物作为钾离子电池的高理论容量阳极,由于其电导率低、循环过程体积膨胀大,导致其倍率性能和循环稳定性较差.本文采用氧化石墨烯(GO)来控制纳米颗粒在纤维中的粒径和分布,以提高复合纤维的导电性和拉伸变形.此外,由异质结构... 详细信息

过渡金属硫化物作为钾离子电池的高理论容量阳极,由于其电导率低、循环过程体积膨胀大,导致其倍率性能和循环稳定性较差.本文采用氧化石墨烯(GO)来控制纳米颗粒在纤维中的粒径和分布,以提高复合纤维的导电性和拉伸变形.此外,由异质结构和氧化石墨烯组成的三维导电碳网络(ZnS-CoS@GO@CNFs)可以加速钾离子储存的动力学并稳定钾离子储存.作为钾离子电池的阳极材料,该复合材料在3 A g^(−1)下具有210 mA h g^(−1)的优异倍率性能.在2 A g^(−1)的大电流下经历2800次循环后仍表现出171 mA h g^(−1)的容量,容量保持率为97.7%.此外,当纳米纤维膜用作自支撑阳极时,仍然可以保持稳定的容量输出(在0.1 A g^(−1)下100次循环后容量为302 mA h g^(−1)).由钾离子混合电容器组装的可折叠袋状电池在多角度重复弯曲和最终恢复的情况下仍然可以安全地工作,并且可以提供大的能量密度(134 W h kg^(−1))和功率密度(5815 W kg^(−1)).优异的电化学性能进一步揭示了多功能氧化石墨烯复合纤维膜的应用前景.

关键词：混合电容器理论容量阳极材料异质结构氧化石墨烯过渡金属硫化物钾离子电化学性能

GJB2 (Cx26) gene mutations in Chinese patients with congenital sensorineural deafness and a report of one novel mutation

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2004年第12期17卷 1797-1801页

作者：肖自安谢鼎华 Department of Otolaryngology & Hearing research Laboratory Second Xiangya Hospital Xiangya School of Medicine Central South University Changsha 410011 China

Background Mutations in GJB2 gene are a major cause of autosomal recessive congenital hearing loss and the cause in some rare cases of the autosomal dominant form The purpose of this study was to investigate the frequency and the features of GJB2 mutations in the Chinese patients with congenital sensorineural deafness Methods Using PCR amplifying the entire coding region of GJB2 gene and direct DNA sequencing to analyze mutations in this gene among unrelated 69 cases with autosomal recessive congenital nonsyndromic deafness and 27 cases of dominant congenital deafness and 35 sporadic cases We also detected mutations in GJB2 in 100 control subjects with normal hearing Results 17 4% (12/69) of the probands in the autosomal recessive, 7 4% (2/27) of dominant families and 5 7% (2/35) of the sporadic congenital deafness patients had deafness causing mutations in GJB2, respectively Nine types of the mutations in GJB2 were detected in the recessive and sporadic group They consisted of five types of polymorphism, and four types of deafness causing mutation with homozygous 35delG in 1 sporadic (1/35), and 235delC frameshift mutation in 1 sporadic (homozygotes) and 10 recessive patients (2 heterozygotes and 8 homozygotes), and homozygous 442G→A missense mutation and homozygous 465T→A nonsense mutation in 1 different recessive proband, respectively The 465T→A that related to recessive deafness was a novel mutation found by this study The homozygous (10/69, 14 5%) and the heterozygous (2/69, 2 9%) GJB2 mutation in the recessive patients (12/69, 17 4%) and the homozygotes in the sporadic patient (2/35, 5 7%) all had congenital severe to profound sensorineural hearing loss 511G→A missense mutation and 299-300delAT frameshift mutation were found in two autosomal dominant congenital deafness families (2/27, 7 4%) The total mutation frequency of GJB2 was 12 2% (16/131) in the Chinese patients with congenital sensorineural deafness and 235delC was the most common deafness causing mut

关键词： hereditary hearing loss sensorieural genes GJB2 mutation

Current trajectory image-based protection algorithm for transmission lines connected to MMC-HVDC stations using CA-CNN

在线全文

学校读者我要写书评

暂无评论

Protection and control of Modern Power Systems 2023年第1期8卷 97-111页

作者： Yingyu Liang Yi Ren Jinhua Yu Wenting Zha School of Mechanical Electronic and Information Engineering China university of Mining and technology(Beijing) Beijing 100083China

In the presence of an MMC-HVDC system,current differential protection(CDP)has the risk of failure in operation under an internal *** addition,CDP may also incur security issues in the presence of current transformer(CT)saturation and *** this paper,a current trajectory image-based protection algorithm is proposed for AC lines connected to MMC-HVDC stations using a convolution neural network improved by a channel attention mechanism(CA-CNN).Taking the dual differential currents as two-dimensional coordinates of the moving point,the moving-point trajectories formed by differential currents have significant differences under internal and external ***,internal faults can be identified using image recognition based on *** is improved by a channel attention mechanism,data augmentation,and adaptive learning *** comparison with other machine learning algorithms,the feature extraction ability and accuracy of CA-CNN are greatly *** fault conditions like different net-work structures,operation modes,fault resistances,outliers,and current transformer saturation,are fully considered to verify the superiority of the proposed protection *** results confirm that the proposed current trajectory image-based protection algorithm has strong learning and generalizability,and can identify internal faults reliably.

关键词： Channel attention mechanism Convolutional neural network(CNN) Differential current Current trajectory image Modular multilevel converter-based high voltage direct current(MMC-HVDC)

Centralized congestion control routing protocol based on multi-metrics for low power and lossy networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2017年第5期24卷 35-43页

作者： Yao Yukun Liu Jiangbing Xu Dongliang Ren Zhi Hu Qing Chongqing Key Laboratory of Mobile Communications technology Chongqing University of Posts and Telecommunications Chongqing 400065 China

Owing to the unreliability of wireless link and the resource constraints of embedded devices in terms of energy, processing power, and memory size in low power and lossy networks （LLNs）, network congestion may occur in an emergency and lead to significant packet loss and end-to-end delay. To mitigate the effect of network congestion, this paper proposes a centralized congestion control routing protocol based on multi-metrics （CCRPM）. It combines the residual energy of a node, buffer occupancy rate, wireless link quality, and the current number of sub-nodes for the candidate parent to reduce the probability of network congestion in the process of network construction. In addition, it adopts a centralized way to determine whether the sub-nodes of the congested node need to be switched based on the traffic analysis when network congestion occurs. Theoretical analysis and extensive simulation results show that compared with the existing routing protocol, the performance of CCRPM is improved significantly in reducing the probability of network congestion, prolonging average network lifetime, increasing network throughput, and decreasing end-to-end delay.

关键词： LLNs congestion control multi-metrics centralized way routing protocol