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Analyzing the multilevel structure of the European airport network 被引量:8
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作者 Oriol Lordan Jose M.Sallan 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第2期554-560,共7页
The multilayered structure of the European airport network(EAN),composed of connections and flights between European cities,is analyzed through the k-core decomposition of the connections network.This decomposition ... The multilayered structure of the European airport network(EAN),composed of connections and flights between European cities,is analyzed through the k-core decomposition of the connections network.This decomposition allows to identify the core,bridge and periphery layers of the EAN.The core layer includes the best-connected cities,which include important business air traffic destinations.The periphery layer includes cities with lesser connections,which serve low populated areas where air travel is an economic alternative.The remaining cities form the bridge of the EAN,including important leisure travel origins and destinations.The multilayered structure of the EAN affects network robustness,as the EAN is more robust to isolation of nodes of the core,than to the isolation of a combination of core and bridge nodes. 展开更多
关键词 Air transport networks Complex networks k-core decomposition network multilevel structure Robustness
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Multilevel security model for ad hoc networks 被引量:1
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作者 Wang Changda Ju Shiguang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第2期391-397,F0003,共8页
Modern battlefield doctrine is based on mobility, flexibility, and rapid response to changing situations. As is well known, mobile ad hoc network systems are among the best utilities for battlefield activity. Although... Modern battlefield doctrine is based on mobility, flexibility, and rapid response to changing situations. As is well known, mobile ad hoc network systems are among the best utilities for battlefield activity. Although much research has been done on secure routing, security issues have largely been ignored in applying mobile ad hoc network theory to computer technology. An ad hoc network is usually assumed to be homogeneous, which is an irrational assumption for armies. It is clear that soldiers, commanders, and commanders-in-chief should have different security levels and computation powers as they have access to asymmetric resources. Imitating basic military rank levels in battlefield situations, how multilevel security can be introduced into ad hoc networks is indicated, thereby controlling restricted classified information flows among nodes that have different security levels. 展开更多
关键词 ad hoc network multilevel security model access control.
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A NEW APPROACH FOR MULTILEVEL IMAGE SEGMENTATION BASED ON FUZZY CELLULAR NEURAL NETWORK
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作者 Zhao Jianye Yu Daoheng (Department of Electronics & Center for Information Science, Peking University, Beijing 100871) 《Journal of Electronics(China)》 2000年第1期46-52,共7页
A new approach for multilevel image segmentation based on fuzzy cellular neural network(CNN) is proposed. Based on a novel fuzzy CNN, a new template is proposed for multilevel image segmentation. The result of compute... A new approach for multilevel image segmentation based on fuzzy cellular neural network(CNN) is proposed. Based on a novel fuzzy CNN, a new template is proposed for multilevel image segmentation. The result of computer simulation proves this approach is reasonable. The stability of the fuzzy neural network is also analyzed in this paper. 展开更多
关键词 multilevel image SEGMENTATION CELLULAR NEURAL network Fuzzy LOGIC
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Chemical Fermentation PoreCreation on Multilevel Bio‑Carbon Structure with In Situ Ni-Fe Alloy Loading for Superior Oxygen Evolution Reaction Electrocatalysis
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作者 Qiaoling Kang Mengfei Su +3 位作者 Yana Luo Ting Wang Feng Gao Qingyi Lu 《Nano-Micro Letters》 2025年第11期191-206,共16页
In the quest for high-efficiency and cost-effective catalysts for the oxygen evolution reaction(OER),a novel biomass-driven strategy is developed to fabricate a unique one-dimensional rod-arrays@two-dimensional interl... In the quest for high-efficiency and cost-effective catalysts for the oxygen evolution reaction(OER),a novel biomass-driven strategy is developed to fabricate a unique one-dimensional rod-arrays@two-dimensional interlaced-sheets(C_(1D@2D))network.A groundbreaking chemical fermentation(CF)pore-generation mechanism,proposed for the first time for creating nanopores within carbon structures,is based on the optimal balance between gasification and solidification.This mechanism not only results in a distinctive C_(1D@2D) multilevel network with nanoscale,intersecting and freely flowing channels but also introduces a novel concept for in situ,extensive and hierarchical pore formation.The unique architecture,combined with the homogeneous dispersion of Ni-Fe nanoparticles,facilitates easy electrolyte penetration and provides abundant active sites for the anchoring and dispersion of reactive molecules or ions.Consequently,the Ni-Fe@C_(1D@2D) porous network demonstrates an exceptional OER electrocatalytic performance,achieving a record-low overpotential of 165 mV at 10 mA cm^(−2)and maintaining long-term stability for over 90 h.Theoretical calculations reveal that the porous structure markedly strengthens the interaction between alloy nanoparticles and the carbon matrix,thereby significantly boosting their electrocatalytic activity and stability.These findings unequivocally validate the CF pore-generation mechanism as a powerful and innovative strategy for designing highly efficient functional nanostructures. 展开更多
关键词 Ni-Fe alloys multilevel porous network Chemical fermentation pore creation Ultra-low overpotential Oxygen evolution reaction electrocatalysts
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基于多电压传感器数据与深度残差网络的MMC子模块开路故障诊断
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作者 吉宇 吴家欣 +4 位作者 曹欣阳 谢金润 郭龚玺 梅军 黄灿 《传感技术学报》 北大核心 2026年第1期139-146,共8页
针对模块化多电平换流器(MMC)子模块IGBT开路故障的隐蔽性和诊断困难,提出一种基于一维深度残差网络(1D-ResNet)的智能诊断方法。首先,利用电压传感器采集子模块电容电压数据,并通过短时傅里叶变换(STFT)提取其时间-频率特征。采用滑动... 针对模块化多电平换流器(MMC)子模块IGBT开路故障的隐蔽性和诊断困难,提出一种基于一维深度残差网络(1D-ResNet)的智能诊断方法。首先,利用电压传感器采集子模块电容电压数据,并通过短时傅里叶变换(STFT)提取其时间-频率特征。采用滑动窗口技术生成大量训练样本,以降低过拟合风险。随后,构建一维深度残差网络进行特征学习与分类,其残差块和跳跃连接结构有效缓解了深层网络的梯度退化问题,增强了对微弱故障特征的捕捉能力。仿真结果表明,所提方法在分类准确率和故障定位时间上显著优于传统支持向量机(SVM)和一维卷积神经网络(1D-CNN)。对比研究进一步验证了该方法具有良好的鲁棒性和实时性,为MMC子模块的IGBT开路故障诊断提供了一种新的有效解决方案。 展开更多
关键词 模块化多电平换流器 故障诊断 卷积神经网络 残差网络 支持向量机
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无线传感器网络级联故障路由恢复算法研究
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作者 蒋秋荣 贺艳峰 冉娜 《传感技术学报》 北大核心 2026年第1期194-199,共6页
无线传感器网络发生级联故障后容易出现路由中断。为了提高无线传感器网络的可靠性和稳定性,提出无线传感器网络级联故障路由恢复算法。采用贪婪算法建链,并以节点与基站距离和剩余能量为评价指标选取链首节点,以此获取无线传感器网络... 无线传感器网络发生级联故障后容易出现路由中断。为了提高无线传感器网络的可靠性和稳定性,提出无线传感器网络级联故障路由恢复算法。采用贪婪算法建链,并以节点与基站距离和剩余能量为评价指标选取链首节点,以此获取无线传感器网络级联故障容忍度;在此基础上量化级联故障影响,当级联故障影响比较大时,通过循环生成备份拓扑子图,根据判别标准构建重要相邻节点集合进行路由恢复。仿真结果表明,正常状态下在第900轮至1000轮之间节点出现死亡情况,节点存活数量较多;级联故障状态下正常节点占比在2 s时降低至48%,实施级联故障路由恢复算法后,迅速恢复为100%且始终保持为100%,具有良好的路由恢复效果。 展开更多
关键词 无线传感器网络 路由恢复算法 多级分层链路算法 贪婪算法 级联故障
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个体水平及群体水平的同伴支持与青少年内化问题的关系:基于社会网络分析方法
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作者 王凌飞 张航 边玉芳 《心理科学》 北大核心 2026年第1期105-120,共16页
同伴支持对青少年心理健康有重要影响。为了探究个体及群体水平同伴支持与青少年内化问题的关系,本研究基于121个班级4056名中学生的调查,借助社会网络分析获取同伴支持网络的个体和群体水平指标,构建多层线性模型。结果发现:(1)学生寻... 同伴支持对青少年心理健康有重要影响。为了探究个体及群体水平同伴支持与青少年内化问题的关系,本研究基于121个班级4056名中学生的调查,借助社会网络分析获取同伴支持网络的个体和群体水平指标,构建多层线性模型。结果发现:(1)学生寻求支持关系越多,焦虑、抑郁和孤独感越低;被寻求支持关系越多,抑郁和孤独感越低;(2)同伴支持网络密度越大,学生的孤独感越低;(3)班级中同伴支持网络密度和寻求支持关系阶层性均能调节个人寻求支持关系数和孤独感之间的关系。研究结果表明,个体水平和群体水平的同伴支持均与青少年内化问题存在负相关,群体水平同伴支持能够调节个体水平同伴支持与内化问题的关系,这对寻求途径降低青少年内化问题有重要的实践意义。 展开更多
关键词 内化问题 青少年 同伴支持 多水平分析 社会网络分析
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基于MLC-YOLO的折纸动作关键目标检测方法
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作者 陈宇聪 何宏 +1 位作者 李泽旭 徐楚迪 《液晶与显示》 北大核心 2026年第2期240-252,共13页
由于简易精神状态检查(CMMSE)量表中“三步指令”的人工评分存在评分者间及自身内部差异,且过程耗时,提出一种基于MLC-YOLO的目标检测方法,旨在实现该动作的自动精准检测。首先,对人体关键部位和纸张进行多级分类目标检测,采用同类极大... 由于简易精神状态检查(CMMSE)量表中“三步指令”的人工评分存在评分者间及自身内部差异,且过程耗时,提出一种基于MLC-YOLO的目标检测方法,旨在实现该动作的自动精准检测。首先,对人体关键部位和纸张进行多级分类目标检测,采用同类极大置信度选择简化后处理,保证同类目标的唯一性;其次,设计自适应空间信道解耦模块,实现高效降采样;然后,在C3中引入幽灵卷积和小波变换,提升多尺度特征提取的效率与能力;最后,针对小目标检测层,引入空间和通道协同注意力,提高复杂场景下的准确率与召回率。实验结果表明:该方法的mAP95达61.8%,较原模型提升5.6%,参数量减少51.52%,证明了方法的有效性,为目标唯一和多级分类的目标检测问题提供了新思路,为MMSE中的“三步指令”的自动评分提供有效的目标检测方法。 展开更多
关键词 深度学习 目标检测 多级分类 轻量化网络
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基于多层注意力卷积神经网络的电缆接头故障识别方法
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作者 王晓康 边疆 +4 位作者 丁雷 马晓强 马学灵 何嘉斌 张童瑞 《绝缘材料》 北大核心 2026年第1期129-137,共9页
电缆系统非稳定性因素主要体现为电缆接头潜在故障,仅凭声音、温度或局部放电等单一信息源检测接头故障难以全面反映其内部特征。结合多参量、多维度特性指标进行特征识别,能有效提升电缆接头故障检测的准确性。本文提出一种基于多层注... 电缆系统非稳定性因素主要体现为电缆接头潜在故障,仅凭声音、温度或局部放电等单一信息源检测接头故障难以全面反映其内部特征。结合多参量、多维度特性指标进行特征识别,能有效提升电缆接头故障检测的准确性。本文提出一种基于多层注意力卷积神经网络的电缆接头故障识别方法,通过离散小波变换将多变量信号源转变为信息更为丰富的时频域多电平特征,并结合时间卷积网络(temporal convolutional network,TCN)和Transformer并行结构拟合数据间的耦合关系,并从采样方式和约束损失函数两个角度对数据集中的数据不平衡问题进行优化处理。针对电缆接头无缺陷、内部绝缘缺陷及接头受潮3种状态的多分类任务进行了实例分析,结果表明该方法能够准确识别电缆接头的故障类型,优化了不同故障类型下识别模式的鲁棒性和适应性。 展开更多
关键词 电缆接头故障 注意力卷积神经网络 多电平特征 数据不平衡
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Monthly Mean Temperature Prediction Based on a Multi-level Mapping Model of Neural Network BP Type 被引量:1
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作者 严绍瑾 彭永清 郭光 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1995年第2期225-232,共8页
In terms of 34-year monthly mean temperature series in 1946-1979,the multi-level maPPing model of neural netWork BP type was applied to calculate the system's fractual dimension Do=2'8,leading tO a three-level... In terms of 34-year monthly mean temperature series in 1946-1979,the multi-level maPPing model of neural netWork BP type was applied to calculate the system's fractual dimension Do=2'8,leading tO a three-level model of this type with ixj=3x2,k=l,and the 1980 monthly mean temperture predichon on a long-t6rm basis were prepared by steadily modifying the weighting coefficient,making for the correlation coefficient of 97% with the measurements.Furthermore,the weighhng parameter was modified for each month of 1980 by means of observations,therefore constrcuhng monthly mean temperature forecasts from January to December of the year,reaching the correlation of 99.9% with the measurements.Likewise,the resulting 1981 monthly predictions on a long-range basis with 1946-1980 corresponding records yielded the correlahon of 98% and the month-tO month forecasts of 99.4%. 展开更多
关键词 Neural network BP-type multilevel mapping model Monthly mean temperature prediction
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Formidable females redux:male social integration into female networks and the value of dynamic multilayer networks 被引量:1
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作者 Tyler R.BONNELL ChloéVILETTE +2 位作者 Christopher YOUNG Stephanus Peter HENZI ouise BARRETT 《Current Zoology》 SCIE CAS CSCD 2021年第1期49-57,共9页
The development of multilayer network techniques is a boon for researchers who wish to understand how different interaction layers might influence each other,and how these in turn might influence group dynamics.Here,w... The development of multilayer network techniques is a boon for researchers who wish to understand how different interaction layers might influence each other,and how these in turn might influence group dynamics.Here,we investigate how integration between male and female grooming and aggression interaction networks influences male power trajectories in vervet monkeys Chlorocebus pygerythrus.Our previous analyses of this phenomenon used a monolayer approach,and our aim here is to extend these analyses using a dynamic multilayer approach.To do so,we constructed a temporal series of male and female interaction layers.We then used a multivariate multilevel autoregression model to compare cross-lagged associations between a male's centrality in the female grooming layer and changes in male Elo ratings.Our results confirmed our original findings:changes in male centrality within the female grooming network were weakly but positively tied to changes in their Elo ratings.However,the multilayer network approach offered additional insights into this social process,identifying how changes in a male's centrality cascade through the other network layers.This dynamic view indicates that the changes in Elo ratings are likely to be short-lived,but that male centrality within the female network had a much stronger impact throughout the multilayer network as a whole,especially on reducing intermale aggression(i.e.,aggression directed by males toward other males).We suggest that multilayer social network approaches can take advantage of increased amounts of social data that are more commonly collected these days,using a variety of methods.Such data are inherently multilevel and multilayered,and thus offer the ability to quantify more precisely the dynamics of animal social behaviors. 展开更多
关键词 multilayer networks multilevel multivariate autoregressive model primate social dynamics social networks SOCIALITY time-aggregated networks vervet monkeys
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Multilevel Feature Moving Average Ratio Method for Fault Diagnosis of the Microgrid Inverter Switch 被引量:5
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作者 Zhanjun Huang Zhanshan Wang Huaguang Zhang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第2期177-185,共9页
Multilevel feature moving average ratio method is proposed to realize an open-switch fault diagnosis for any switch of the microgrid inverter. The main steps of the proposed method include multilevel signal decomposit... Multilevel feature moving average ratio method is proposed to realize an open-switch fault diagnosis for any switch of the microgrid inverter. The main steps of the proposed method include multilevel signal decomposition, coefficient reconstruction, absolute average ratio process and artificial neural network U+0028 ANN U+0029 classification. Specifically, multilevel signal decomposition is realized by using the means of multi resolution analysis to obtain the different frequency band coefficients of the three-phase current signal. The related coefficient reconstruction is executed to achieve signals decomposition in different levels. Furthermore, according to the obtained data, the absolute average ratio process is used to extract absolute moving average ratio of signal decomposition in different levels for the three-phase current. Finally, to intelligently classify the inverter switch fault and realize the adaptive ability, the ANN technology is applied. Compared to conventional fault diagnosis methods, the proposed method can accurately detect and locate the open-switch fault for any location of the microgrid inverter. Additionally, it need not set related threshold of algorithm and does not require normalization process, which is relatively easy to implement. The effectiveness of the proposed fault diagnosis method is demonstrated through detailed simulation results. © 2017 Chinese Association of Automation. 展开更多
关键词 Deep neural networks Electric inverters Failure analysis Frequency bands Neural networks Signal distortion Signal processing
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A Novel Multi-Level Trust Algorithm for Mobile Ad Hoc Networks
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作者 YU Genjian ZHENG Baoyu 《Wuhan University Journal of Natural Sciences》 CAS 2006年第6期1789-1792,共4页
Firstly, a multilevel trust algorithm for MANET (mobile ad hoe networks) is presented in this paper and the trust level is defined as a three-tuple type in this multilevel trust algorithm. The paper introduces the m... Firstly, a multilevel trust algorithm for MANET (mobile ad hoe networks) is presented in this paper and the trust level is defined as a three-tuple type in this multilevel trust algorithm. The paper introduces the multilevel trust into MANET, thereby controlling restricted classified information flows among nodes that have different trust levels. Secondly, the infrastructure of MANET that suit to our multi-level trust is presented, Some conclusions are given at lastly. 展开更多
关键词 MANET(mobile ad hoe networks) multilevel trust algorithm
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Stock trend prediction method coupled with multilevel indicators
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作者 Liu Yu Pan Yuting Liu Xiaoxing 《Journal of Southeast University(English Edition)》 EI CAS 2024年第4期425-431,共7页
To systematically incorporate multiple influencing factors,the coupled-state frequency memory(Co-SFM)network is proposed.This model integrates Copula estimation with neural networks,fusing multilevel data information,... To systematically incorporate multiple influencing factors,the coupled-state frequency memory(Co-SFM)network is proposed.This model integrates Copula estimation with neural networks,fusing multilevel data information,which is then fed into downstream learning modules.Co-SFM employs an upstream fusion module to incorporate multilevel data,thereby constructing a macro-plate-micro data structure.This configuration helps identify and integrate characteristics from different data levels,facilitating a deeper understanding of the internal links within the financial system.In the downstream model,Co-SFM uses a state-frequency memory network to mine hidden frequency information within stock prices,and the multifrequency patterns of sequential data are modeled.Empirical results show that Co-SFM s prediction accuracy for stock price trends is significantly better than that of other models.This is especially evident in multistep medium and long-term trend predictions,where integrating multilevel data results in notably improved accuracy. 展开更多
关键词 stock trend prediction multilevel indicators COPULA state-frequency memory network
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MSONoC: a non-blocking optical interconnection network for inter cluster communication
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作者 Jiang Lin Cui Pengfei +1 位作者 Shan Rui Wu Haoyue 《High Technology Letters》 EI CAS 2020年第3期262-269,共8页
Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and... Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and the data delay increases dramatically. With the advent of optical router, the traditional electrical interconnection mode has changed to optical interconnection mode. In the packet switched optical interconnection network, the data communication mechanism consists of 3 processes: link establishment, data transmission and link termination, but the circuit-switched data transmission method greatly limits the utilization of resources. The number of micro-ring resonators in the on-chip large-scale optical interconnect network is an important parameter affecting the insertion loss. The proposed λ-route, GWOR, Crossbar structure has a large overall network insertion loss due to the use of many micro-ring resonators. How to use the least micro-ring resonator to realize non-blocking communication between multiple cores has been a research hotspot. In order to improve bandwidth and reduce access latency, an optical interconnection structure called multilevel switching optical network on chip(MSONoC) is proposed in this paper. The broadband micro-ring resonators(BMRs) are employed to reduce the number of micro-ring resonators(MRs) in the network, and the structure can provide the service of non-blocking point to point communication with the wavelength division multiplexing(WDM) technology. The results show that compared to λ-route, GWOR, Crossbar and the new topology structure, the number of micro-ring resonators of MSONoC are reduced by 95.5%, 95.5%, 87.5%, and 60% respectively. The insertion loss of the minimum link of new topology, mesh and MSONoC structure is 0.73 dB, 0.725 dB and 0.38 dB. 展开更多
关键词 network on chip(NoC) optical interconnection wavelength division multiplexing(WDM) NON-BLOCKING multilevel switching
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中性点不接地柔直配电网的单极接地故障暂态过程分析及保护新方案 被引量:2
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作者 张艳霞 宋金孺 张子扬 《电力自动化设备》 北大核心 2025年第2期94-102,共9页
针对中性点不接地的柔直配电网分析了直流馈线发生单极接地故障的暂态过程,提出了单极接地保护新方案,能有效解决现有直流线路保护不能反应中性点不接地柔直配电网的单极接地故障问题。在单极接地故障的分析中,将故障发展过程分为子模... 针对中性点不接地的柔直配电网分析了直流馈线发生单极接地故障的暂态过程,提出了单极接地保护新方案,能有效解决现有直流线路保护不能反应中性点不接地柔直配电网的单极接地故障问题。在单极接地故障的分析中,将故障发展过程分为子模块电容放电阶段和交流重新馈入充电阶段。基于叠加原理分析了子模块电容放电阶段的电流流通路径、直流馈线暂态零模电流的电流成分和变化规律,得到故障馈线暂态零模电流主要呈现衰减非周期分量特征、非故障馈线暂态零模电流主要呈现振荡衰减分量特征的结论;利用牛顿迭代法推导了交流重新馈入充电的时刻,分析了影响因素并计算了过渡过程持续的最短时间。基于子模块电容放电开始时刻至交流重新馈入充电时刻这一段的暂态特征提出单极接地保护方案。该方案利用直流母线出现的零模电压启动保护,利用零模电压极性实现故障选极,利用故障馈线暂态零模电流绝对值的第一个积分时段值大于非故障馈线的值、且呈现衰减非周期分量特征选出故障馈线。搭建仿真模型,对故障分析结果和保护方案的有效性进行了验证。 展开更多
关键词 柔直配电网 直流中性点不接地 模块化多电平换流器 单极接地故障 暂态特性 零模分量 继电保护
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考虑枢纽平衡的干支通多层航空运输网络优化模型
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作者 姜雨 林操 +1 位作者 龙颖 薛清文 《交通运输工程学报》 北大核心 2025年第6期186-199,共14页
为推动干支通多层航空运输网络构建和高效运行,考虑轴辐式航线网络的多层级特性以及通用航空与干支运输网络的衔接规则,研究了干支通多层航空运输网络优化方法。以网络运输成本和枢纽建设成本最小、最长运输时间最小、枢纽不平衡利用率... 为推动干支通多层航空运输网络构建和高效运行,考虑轴辐式航线网络的多层级特性以及通用航空与干支运输网络的衔接规则,研究了干支通多层航空运输网络优化方法。以网络运输成本和枢纽建设成本最小、最长运输时间最小、枢纽不平衡利用率最小为目标函数,构建了考虑容量限制的r分配非严格轴辐式网络多目标优化模型;结合多目标优化模型的特点,设计VNS-NSGA-Ⅲ进行求解,引入变邻域搜索算法,设计了6种不同的邻域结构来避免陷入局部最优;选取华北地区的部分机场进行小规模与大规模干支通航线网络建模求解,验证VNS-NSGA-Ⅲ的有效性,并进行了参数灵敏度分析。研究结果表明:相同参数条件下,与其他算法相比,VNS-NSGA-Ⅲ的反向世代距离最小(0.043 78),证明其获得的Pareto解具有更好的多样性和收敛性;灵敏度分析结果表明普通枢纽数量从2增至8时,成本、时间和不平衡利用率目标分别下降了21.94%、23.20%和50.00%,中心枢纽数量从2增至5时,3个目标分别下降了13.86%、13.08%和33.52%;对于不同的分配策略,多分配模型在成本和时间目标上优于单分配模型,但多分配模型在增强路径灵活性的同时,容易增加关键枢纽负载,造成枢纽利用不均衡;枢纽选址结果、分配策略以及非枢纽连通性显著影响网络的流量分布情况和目标函数值。 展开更多
关键词 航空运输 航线网络 NSGA-Ⅲ 多目标优化 通用航空 干支通多层航空运输网络
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基于多层服务网络的铁路商品车空重混编班列开行方案优化方法 被引量:2
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作者 袁志聪 李海鹰 +2 位作者 张娜 王莹 张家瑞 《铁道学报》 北大核心 2025年第5期12-21,共10页
针对我国铁路商品车运输中重车组织和空车调配相对独立的现状,以提高班列开行比例为出发点,提出空重混编班列开行方案优化方法。分析铁路商品车运输专用车辆JSQ型车的重车运输组织过程,结合空车调配特点,提出空重混编班列开行的可行性;... 针对我国铁路商品车运输中重车组织和空车调配相对独立的现状,以提高班列开行比例为出发点,提出空重混编班列开行方案优化方法。分析铁路商品车运输专用车辆JSQ型车的重车运输组织过程,结合空车调配特点,提出空重混编班列开行的可行性;建立铁路商品车“空车-重车-班列”3层服务网络,分别刻画空车调配流程、重车运输组织和班列开行特征,并建立空重混编班列开行方案优化模型;基于实例数据,采用Gurobi求解并进行灵敏度分析,结果表明提出的方法能够生成铁路商品车空重混编班列开行方案,并给出较优的空车调配方案。实例计算结果中,重车运输时效性提高39.56%,空车调配效率提升44.44%,实现提高商品车铁路运输时效、促进满轴满编、加快车辆周转等目标。 展开更多
关键词 空重混编班列 多层服务网络 商品车 开行方案
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基于积分面积的直流配网单极接地故障选线方法 被引量:2
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作者 豆敏娜 田影 +5 位作者 王毅钊 王晓卫 屈新宇 王雪 岳阳 张志华 《电网与清洁能源》 北大核心 2025年第1期10-16,共7页
在柔性直流配电系统中,因存在低惯性、弱阻尼特性,导致系统发生单极接地故障时系统故障电流大,且故障过程发展极快,对保护方案的快速性和可靠性提出了更高要求。分析直流配电网发生单极接地故障时的故障电流特征,并根据故障发生后健全... 在柔性直流配电系统中,因存在低惯性、弱阻尼特性,导致系统发生单极接地故障时系统故障电流大,且故障过程发展极快,对保护方案的快速性和可靠性提出了更高要求。分析直流配电网发生单极接地故障时的故障电流特征,并根据故障发生后健全馈线与故障馈线的正、负极电流在大小与方向之间存在的差异,提出一种基于积分面积的直流配网单极接地故障选线方法。在电磁暂态仿真软件(power systems computer aided design,PSCAD)上搭建基于模块化多电平换流器(modular multilevel converter,MMC)单端柔直配电网,验证所述方案的有效性。仿真结果表明:该选线方案能够快速、准确、可靠地识别线路;具有一定的耐受过渡电阻、不同数据窗的能力。 展开更多
关键词 单极接地故障 直流配电网 故障选线 模块化多电平换流器
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柔性直流配电网中接地故障检测技术研究 被引量:1
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作者 郑峰 吕佳雯 +1 位作者 林燕贞 梁宁 《电机与控制学报》 北大核心 2025年第4期54-64,共11页
针对柔性直流配电系统拓扑结构复杂,故障种类多、故障识别难度大等问题,提出一种基于相对熵(K-L)散度优化变分模态分解(VMD)与结合Inception的卷积神经网络(CNN)的故障检测方法,该方法首先对故障点的正极暂态电压时域波形采用K-L VMD方... 针对柔性直流配电系统拓扑结构复杂,故障种类多、故障识别难度大等问题,提出一种基于相对熵(K-L)散度优化变分模态分解(VMD)与结合Inception的卷积神经网络(CNN)的故障检测方法,该方法首先对故障点的正极暂态电压时域波形采用K-L VMD方法提取特征分量,利用特征模态分量构造识别判据,接着对采样数据进行CNN训练,获取模型最优参数,最后利用仿真平台搭建了一个基于模块化多电平变换器(MMC)的10 kV两端直流配电网结构来验证所提方法的有效性,仿真实验表明利用K-L散度优化变分模态分解对仿真数据进行处理,具有良好的推广能力,且具备对噪声的抗干扰能力,所提出的故障检测方法有效,对于各种故障类型的识别具有较强的灵敏性,能准确识别故障类型。 展开更多
关键词 柔性直流配电网 K-L散度优化 变分模态分解 卷积神经网络 故障检测 模块化多电平变换器
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