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
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
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
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
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
针对多端柔性直流电网(multi-terminal direct current grid based on modular multilevel converter,MMC-MTDC)故障诊断存在的人工整定阈值过程复杂、高阻故障不易检测的问题,提出一种基于行波特征的诊断方法。首先,通过分析系统的故...针对多端柔性直流电网(multi-terminal direct current grid based on modular multilevel converter,MMC-MTDC)故障诊断存在的人工整定阈值过程复杂、高阻故障不易检测的问题,提出一种基于行波特征的诊断方法。首先,通过分析系统的故障特征,得出边界元件对高频信号的阻滞作用;其次,利用经验模态分解(empirical mode decomposition,EMD)对功率进行分解,得到本征模态函数(intrinsic mode function,IMF)分量,将其能量值作为故障特征量训练由卷积神经网络(convolutional neural network,CNN)和双向门控循环单元(bidirectional gated recurrent unit,BiGRU)组成的CNN-BiGRU网络;然后,采用开普勒优化算法(Kepler optimization algorithm,KOA)和注意力机制(attention mechanism,AM)对CNN-BiGRU网络进行改进,实现MMC-MTDC的故障诊断;最后,在PSCAD/EMTDC中搭建仿真模型。结果表明,该方法不仅可以实现母线故障和线路故障的检测,还可以在满足保护可靠性和速动性的前提下,解决高阻故障保护易拒动的问题。展开更多
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
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
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
基金supported by the National Natural Science Foundation of China(Grant No.22275082 and 22175084).
文摘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.
文摘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.
基金the National Natural Science Foundation of China (60773049)the Natural Science Foundationof Jiangsu Province (BK2007086)the Fundamental Research Project of Natural Science in Colleges of Jiangsu Province(07KJB520016).
文摘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.
文摘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.
基金The National Natural Science Foundation of China(No.72173018).
文摘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.
文摘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%.
基金This work was funded by NRH(South Africa)and UNISA awards(S.P.H.),NSERC(Canada)Discovery grants(L.B.,S.P.H.)the NSERC Canada Research Chair program(L.B.)+2 种基金C.Y.is the recipient of a University of Pretoria Senior Postdoctoral FellowshipT.B.has been funded by an FQNRT Post-Doctoral FellowshipT.B.and C.V.are currently funded by NSERC Canada Research Chair and Discovery Grants held by L.B.
文摘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.
基金supported by National Natural Science Foundation of China(61473070,61433004)Fundamental Research Funds for the Central Universities(N130504002)SAPI Fundamental Research Funds(2013ZCX01)
基金Supported by the National Natural Science Foun-dation of China (60372107) Doctoral Innovative Foundation ofJiangsu Province(46666001) .
文摘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.
