检索结果-南通市图书馆

Outlier Robust Feature Correspondence by Learning Based Matching Process

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第4期37卷 1351-1367页

作者： YANG Xu ZENG Shaofeng liu zhiyong State Key Laboratory of Multimodal Artificial Intelligence Systems Institute of Automation of Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China

Feature correspondence is a crucial aspect of various computer vision and robot vision *** traditional optimization-based matching techniques,researchers have recently adopted a learning-based approach for matching,but these methods face challenges in dealing with outlier *** paper presents an outlier robust feature correspondence method that employs a pruned attentional graph neural network and a matching layer to address the outlier ***,the authors introduce a modified cross-entropy matching loss to handle the outlier *** a result,the proposed method significantly enhances the performance of learning-based matching algorithms in the presence of outlier *** experiments confirm the effectiveness of the proposed approach.

关键词： Feature correspondence graph neural network optimal transport problem pointmatching

Modulation of driving signals in flow control over an airfoil with synthetic jet

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2020年第12期33卷 3138-3148页

作者： zhiyong liu Zhenbing LUO Qiang liu Yan ZHOU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China China Aerodynamics Research and Development Center Mianyang 621000China

A new skill of modulating driving signals of a synthetic jet with low frequency is introduced to enhance the control *** on dynamic mesh technique,the effect of flow control over a NACA0015 airfoil with a Synthetic Jet Actuator(SJA)has been *** SJA is located at x/c=10%,and two jet injection angles of 90°and 30°have been *** structures indicate that modulation with low frequency can reduce the dissipation rate of vortices after they shed off the *** aerodynamic performance of the airfoil could be *** the injection angle of 90°,modulation can increase the control authority of the *** to the unmodulated case,increment of lift-to-drag ratio is up to 15%.The modulating frequency corresponding to the largest increment is F_(M)^(+)≈*** the injection angle of 30°,improvement of aerodynamic forces positively relates to momentum coefficient of the *** to the decrease of effective momentum,modulation degrades the effect of flow *** opposite responses to modulation are believed to have a relationship with the variation of primary control *** jet injection angle varies from 90°to 30°,the primary mechanism changes from the interaction of vortices and waves to the direct momentum *** skill of modulation of driving signals is very useful for applications of SJA.

关键词： Airfoil Flow control Injection angle Modulation Momentum coefficient Synthetic jet

Potential effects of automated driving on vehicle travel demand: A comparison of three case cities

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 348-361页

作者： Jingchen Dai Ruimin Li zhiyong liu School of Civil Engineering Tsinghua UniversityBeijing 100084China Hang Lung Center for Real Estate Tsinghua UniversityBeijing 100084China School of Traffic and Transportation Beijing Jiaotong UniversityBeijing 100044China

Automated vehicles(AVs)hold the potential to reduce road accidents,mitigate traffic congestion,and improve travel ***,the possible countervailing impacts from the changes in underserved populations’vehicle travel demand tend to be *** determine the vehicle travel demand changes that resulted from underserved populations aged between 6 and 80,this paper explores the latent effect of AVs on vehicle kilometers traveled(VKT)in a fully AV environment using person trip survey data from the cities of Sanya,Shijiazhuang,and Shenzhen in *** paper uses the natural decline hypothesis of travel demand and proposes a regression model to investigate the difference among the cities’latent vehicle travel *** show that the average VKT of the overall population in Sanya,Shijiazhuang,and Shenzhen increased by 33.4%,47.0%,and46.8%,*** analysis of the regression model confirms that the current travel behavior of individuals can affect the degree of increase in their average *** AVs into public transport,increasing the acceptance of automated shared mobility options,transforming road space use type,and prototyping AV designs with various features and needs are potential methods to cope with the countervailing *** total VKT of the overall population increased by approximately 10%-25%depending on the *** conclusions of this paper provide informative insights into the evaluation of VKT for underserved populations and contribute to the deployment of AVs to address equity and inclusion issues.

关键词： Automated vehicles Vehicle kilometers traveled Aging population Travel behavior Natural decline hypothesis

Electrochemical studies of microbiologically influenced corrosion of X80 steel by nitrate-reducing Bacillus licheniformis under anaerobic conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第23期118卷 208-217页

作者： Jun Li Cuiwei Du zhiyong liu Xiaogang Li School of Materials Science and Engineering Chang’an UniversityXi’an 710064China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Key Laboratory for Corrosion and Protection of the Ministry of Education(MOE) Beijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China

In this work, the impact of a wild-type nitrate-reducing Bacillus licheniformis strain on the corrosion behavior of X80 steel under anaerobic conditions was studied by electrochemical tests and biofilm characterization. The bioelectrochemical, electrochemical, and chemical reactions between X80 steel and microorganisms were investigated comprehensively. The results show that B. licheniformis can accelerate the corrosion of X80 steel substrate in early immersing by two ways: biocatalytic cathodic nitrate reduction and acidification induced by bacterially-secreted acids. However, the corrosion rate of X80 steel decreased after immersing for ca. 1 week in B. licheniformis culture due to iron biomineralization. This work provides direct insights into the mechanism of microbiologically influenced corrosion of carbon steel by the nitrate-reducing bacterium.

关键词： Microbiologically influenced corrosion X80 steel Nitrate-reducing bacteria Electrochemical tests Biofilm characterization

Restricted Additive Schwarz Preconditioner for Elliptic Equations with Jump Coefficients

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2016年第6期8卷 1072-1083页

作者： zhiyong liu Yinnian He School of Mathematics and Computer Science Ningxia UniversityYinchuan 750021China Center for Computational Geosciences School of Mathematics and StatisticsXi’an Jiaotong UniversityXi’an 710049China

This paper provides a proof of robustness of the restricted additive Schwarz preconditioner with harmonic overlap(RASHO)for the second order elliptic problems with jump *** analyzing the eigenvalue distribution of the RASHO preconditioner,we prove that the convergence rate of preconditioned conjugate gradient method with RASHO preconditioner is uniform with respect to the large jump and meshsize.

关键词： Jump coefficients conjugate gradient effective condition number domain decomposition,restricted additive Schwarz.

Magic angles and flat Chern bands in alternating-twist multilayer graphene system

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 Materials Science & Technology 2022年第16期111卷 28-34页

作者： zhiyong liu Wenyuan Shi Teng Yang Zhidong Zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Western Reserve Academy 115 College Street HudsonOhio 44236United States

Based on the effective continuum model,we study alternating-twist multilayer graphene system and emergence of magic angles and flat band *** the alternating-twist multilayer graphene system(from triple layers to few layers)are found to have flat bands at magic angles where the area of AA stacking equals n-fold(n is an integer)electron cyclotron *** the pseudo-Landau-level representation,there is always an isolated Dirac band in the alternating-twist graphene system constructed by odd number of *** each pair of flat bands can be perceived as the zeroth pseudo-Landau-levels in two dimensional Dirac fermions,electron in the flat band pair can feel a pseudo-magnetic field with the same magnitude but the opposite *** Chern number for each flat band is+1(or-1)which can be tuned by twisting in the vicinity of magic angles or by *** concurrent appearance of strong correlation and band topology of flat bands in the alternating-twist multilayer graphene may pave an avenue for the new understanding of superconductivity observed in triple-layered graphene,and supply a new playground for realizing(quantum)anomalous Hall effect.

关键词： Alternating-twist multilayer graphene Magic angle Flat band Band topology

Stability of water yield in watersheds

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第2期67卷 483-496页

作者： Yu YAN zhiyong liu Xiaohong CHEN Liyan HUANG Center for Water Resources and Environment School of Civil EngineeringSun Yat-Sen UniversityGuangzhou510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519082China

The hydrological system of a watershed is intricately influenced by both underlying characteristics and climate *** the variability in water yield is essential for effective water resources management and water security in the context of changing *** this study,we adopted the Budyko framework and leveraged simulations from the CMIP6 model to investigate the compensation effects of climate and underlying characteristics on watershed water *** on Taylor expansion and Budyko framework,we estimated the sensitivity of watershed water yield to climate and underlying characteristics(the first-and second-order partial derivatives).By combining external watershed characteristics(e.g.,water yield ratios and underlying characteristics)with internal sensitivity coefficients,this study further used vine copula and principal component analysis to quantify the stability of watershed water *** findings show:(1)Water-yield changes related to underlying characteristics could be offset by climate-related water-yield changes across all climate zones,maintaining the water yield ratio steady(i.e.,the compensation effects).(2)However,global watersheds will turn more sensitive to underlying characteristics and less sensitive to climate variation in the *** climate-and underlying-related sensitivities increase in watersheds with arid climates.(3)The stability of watershed water yield will gradually diminish in the *** 1901–1950to 2051–2100,the global stability of 280 watersheds drops from 0.054 to 0.021(i.e.,stability index identified by the joint probability).Particularly,the largest change in stability of water yield reaches-0.347±0.18 in arid *** semi-arid,semihumid,and humid regions,the changes are-0.039±0.010,-0.028±0.005,and-0.005±0.002,*** findings provide a reference for the future sustainable water resources development under climate change,highlighting the vulnerability of the water resources in ari

关键词： Hydrological system stability Compensation effects on water yield Sensitivities Budyko-Fu decomposition framework Global watersheds

Effect of deteriorated microstructures on stress corrosion cracking of X70 pipeline steel in acidic soil environment

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2008年第6期15卷 707-713页

作者： zhiyong liu Guoli Zhai Xiaogang Li Cuiwei Du Corrosion and Protection Center University of Science and Technology Beijing Beijing 100083 China

In order to investigate stress corrosion cracking （SCC） of X70 pipeline steel and its weld joint area in acidic soil environ- ment in China, two simulating methods were used： one was to obtain bad microstructures in heat affected zone by annealing at 1300 ℃ for 10 min and then, quenching in water; the other was to get different simulating solutions of acidic soil in Yingtan in south- east China. The SCC susceptibilities of X70 pipeline steel before and after quenching in the simulating solutions were analyzed using slow stain rate test （SSRT） and potentiodynamic polarization technique to investigate the SCC electrochemical mechanism of different microstructures further. The results show that SCC appears in the original microstructure and the quenched microstructure as the polarization potential decreases. Hydrogen revolution accelerates SCC of the two tested materials within the range of-850 mV to -1200 mV vs. SCE. Microstructural hardening and grain coarsening also increase SCC. The SCC mechanisms are different, anodic dissolution is the key of causing SCC as the polarization potential is higher than the null current potential, and hydrogen embrittlement will play a more important role to SCC as the polarization potential lower than the null current potential.

关键词： X70 steel heat affected zone heat treatment stress corrosion cracking (SCC) acidic soil environment

New selection rule of resonant Raman scattering in MoS_(2) monolayer under circular polarization

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第7期102卷 132-136页

作者： Jianqi Huang zhiyong liu Teng Yang Zhidong Zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The first-order resonant Raman spectra of monolayer MoS_(2)are calculated under the circularly polarized *** anomalously nonzero Raman intensity of the in-plane E mode under the Z(σ+σ+)Zor Z(σ−σ−)Zgeometry,which goes against the conventional selection rule,appears under some circum-stances when optical absorption occurs at some special reciprocal points between the zone-center Γ and the zone-edge-center M *** that moment,the valley selectivity to the circular polarization is *** analysis shows that the anomalous Raman intensity of the E mode for the same circularly polarized incident and scattered light is consistent with the pseudo-angular-momentum conservation *** cal-culated E Raman tensor of monolayer MoS_(2)is found to vary with laser *** two diagonal terms of the Raman tensor change their signs from mutually opposite to the same when the relative intensity of the in-plane E mode to the out-of-plane A'_(1)mode increases,indicating the increasingly important role played by the Frölich-type electron-phonon interaction over the deformation *** study may shed new light on the understanding of the novel electron-photon process and assist in the design of new type of optoelectronic devices.

关键词： First principles calculation Resonant Raman Helicity selection rule MoS2 monolayer