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Exploring the limits of complexity: A survey of empirical studies on graph visualisation

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Visual Informatics 2018年第4期2卷 264-282页

作者： Vahan Yoghourdjian Daniel Archambault Stephan Diehl Tim Dwyer Karsten Klein Helen C.Purchase hsiang-yun wu Monash University Australia Swansea University United Kingdom University of Trier Germany University of Konstanz Germany University of Glasgow United Kingdom University of TU Wien Austria

For decades,researchers in information visualisation and graph drawing have focused on developing techniques for the layout and display of very large and complex *** involving human participants have also explored the readability of different styles of layout and representations for such *** both bodies of literature,networks are frequently referred to as being‘large’or‘complex’,yet these terms are *** a human-centred,experiment point-of-view,what constitutes‘large’(for example)depends on several factors,such as data complexity,visual complexity,and the technology *** this paper,we survey the literature on human-centred experiments to understand how,in practice,different features and characteristics of node–link diagrams affect visual complexity.

关键词： Graph visualisation Network visualisation node-link diagrams Cognitive scalability Evaluations Empirical studies

Effect of the vortical structures on the hydrodynamic performance of a pitching hydrofoil

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Journal of Hydrodynamics 2024年第2期36卷 406-420页

作者： Rui Yuan Hui-yun Hao Qin wu yun-qing Liu Biao Huang School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

The objective is to study the vortical structural behaviors of a transient pitching hydrofoil and their effects on the hydrodynamic performance. The pitching motion of the hydrofoil is set to pitch up with an almost constant rate from 5° to 15° and then back to 5°, with the Reynolds number 4.4×10^(5) and the frequency 2 Hz. The results show that the main coherent structures around the pitching hydrofoil include small-scale laminar separation bubble (LSB), large-scale second vortex (SV) and trailing edge vortex (TEV) which are all vortical. The relationship between the vortical structure and the lift is investigated with the finite-domain impulse theory. It indicates that the major part of the lift is contributed by the LSB, whereas the shedding and the formation of the SV and TEV cause the fluctuation of the lift. The proper orthogonal decomposition (POD) method is applied to capture the most energetic modes, revealing that the LSB mode occupies a large amount of energy in the flow field. The dynamic mode decomposition (DMD) method accurately extracts the dominant frequency and modal characteristics, with the first mode corresponding to the mean flow, the second mode corresponding to the LSB structure and the third and fourth modes corresponding to the vortex shedding.

关键词： Hydrodynamics vortical structures finite-domain impulse theory proper orthogonal decomposition(POD) dynamic mode decomposition(DMD) Pitching hydrofoil

Visualization Working Group at TU Wien Visible Facimus Quod Ceteri Non Possunt

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Visual Informatics 2021年第1期5卷 76-84页

作者： hsiang-yun wu Aleksandr Amirkhanov Nicolas Grossmann Tobias Klein David Kouřil Haichao Miao Laura R.Luidolt Peter Mindek Renata G.Raidou Ivan Viola Manuela Waldner M.Eduard Gröller TU Wien Austria

Building-up and running a university-based research group is a multi-faceted *** visualization working group at TU Wien(vis-group)has been internationally active over more than 25 *** group has been acting in a competitive scientific setting where sometimes contradicting multiple objectives require trade-offs and ***-wise the group has been performing basic and applied research in visualization and visual ***-wise the group has been involved in undergraduate and graduate lecturing in(medical)visualization and computer *** be scientifically competitive requires to constantly expose the group and its members to a strong international competition at the highest *** necessitates to shield the members against the ensuing pressures and demands and provide(emotional)support and ***,the vis-group has developed a unique professional and social interaction culture:work and celebrate,hard and *** has crystallized into a nested,recursive,and triangular organization model,which concretizes what it takes to make a research group *** key elements are the creative and competent vis-group members who collaboratively strive for(scientific)excellence in a socially enjoyable environment.

关键词： Vis-group Visualization Visual analytics Visual modelitics Visual datascience

A Novel CCA-NMF Whitening Method for Practical Machine Learning Based Underwater Direction of Arrival Estimation

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Journal of Beijing Institute of Technology 2024年第2期33卷 163-174页

作者： yun wu Xinting Li Zhimin Cao School of Physics and Electronic Engineering Northeast Petroleum UniversityDaqing 163318China

Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical *** to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based DOA estimation methods trained on simulated Gaussian noised array data cannot be directly applied to actual underwater DOA estimation *** order to deal with this problem,environmental data with no target echoes can be employed to analyze the non-Gaussian ***,the obtained information about non-Gaussian components can be used to whiten the array *** on these considerations,a novel practical sonar array whitening method was ***,based on a weak assumption that the non-Gaussian components in adjacent patches with and without target echoes are almost the same,canonical cor-relation analysis(CCA)and non-negative matrix factorization(NMF)techniques are employed for whitening the array *** the whitened array data,machine learning based DOA estimation models trained on simulated Gaussian noised datasets can be used to perform underwater DOA estimation *** results illustrated that,using actual underwater datasets for testing with known machine learning based DOA estimation models,accurate and robust DOA estimation performance can be achieved by using the proposed whitening method in different underwater con-ditions.

关键词： direction of arrival(DOA) sonar array data underwater disturbance machine learn-ing canonical correlation analysis(CCA) non-negative matrix factorization(NMF)

Targeting synaptic pathology in Alzheimer’s disease

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Zoological Research 2024年第4期45卷 875-876页

作者： Jing Cao yun-wu Zhang Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research Institute of NeuroscienceSchool of MedicineXiamen UniversityXiamenFujian 361102China

Alzheimer’s disease(AD)is a neurodegenerative disorder characterized by memory and cognitive *** two primary pathological hallmarks of AD include the accumulation ofβ-amyloid(Aβ)plaques and formation of neurofibrillary tangles(NFTs)composed predominantly of hyperphosphorylated tau protein(Zhang et al.,2023).Moreover,synaptic dysfunction is considered another crucial factor in AD pathogenesis and is closely associated with cognitive ***,synaptic damage,loss,and dysfunction manifest earlier than the pathological features of Aβplaques and NFTs(Knopman et al.,2021).Therefore,understanding the mechanisms underlying synaptic dysfunction in AD is vital for providing insights into disease mechanisms and developing novel therapeutic strategies.

关键词： Alzheimer Aβ tau

Representation learning: serial-autoencoder for personalized recommendation

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Frontiers of Computer Science 2024年第4期18卷 61-72页

作者： Yi ZHU Yishuai GENG yun LI Jipeng QIANG Xindong wu School of Information Engineering Yangzhou UniversityYangzhou 225127China Key Laboratory of Knowledge Engineering with Big Data(Ministry of Education of the People’s Republic of China) Hefei University of TechnologyHefei 230009China School of Computer Science and Information Engineering Hefei University of TechnologyHefei 230009China

Nowadays,the personalized recommendation has become a research hotspot for addressing information *** this,generating effective recommendations from sparse data remains a ***,auxiliary information has been widely used to address data sparsity,but most models using auxiliary information are linear and have limited *** to the advantages of feature extraction and no-label requirements,autoencoder-based methods have become quite ***,most existing autoencoder-based methods discard the reconstruction of auxiliary information,which poses huge challenges for better representation learning and model *** address these problems,we propose Serial-Autoencoder for Personalized Recommendation(SAPR),which aims to reduce the loss of critical information and enhance the learning of feature ***,we first combine the original rating matrix and item attribute features and feed them into the first autoencoder for generating a higher-level representation of the ***,we use a second autoencoder to enhance the reconstruction of the data representation of the prediciton rating *** output rating information is used for recommendation *** experiments on the MovieTweetings and MovieLens datasets have verified the effectiveness of SAPR compared to state-of-the-art models.

关键词： personalized recommendation autoencoder representation learning collaborative filtering

Electronic structural engineering of bimetallic Bi-Cu alloying nanosheet for highly-efficient CO_(2) electroreduction and Zn-CO_(2) batteries

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Nano Research 2024年第5期17卷 3684-3692页

作者： Wenbo wu Jiaye Zhu yun Tong Shuangfei Xiang Pengzuo Chen School of Chemistry and Chemical Engineering Key Laboratory of Surface and Interface Science of Polymer Materials of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China

Regulating the electronic structure of Bi-based materials by alloying engineering is promising to promote the electrocatalytic activity,but it remains some challenges to be *** this study,a facile electrochemical co-deposition strategy is developed to synthesize the bimetallic Bi_(9)Cu_(1) alloy nanosheet on carbon cloth(Bi_(9)Cu_(1)/CC),which represents a novel self-supporting electrode for the electrocatalytic carbon dioxide(CO_(2))reduction reaction(CO_(2)RR).The Bi_(9)Cu_(1)/CC catalyst has achieved a remarkable catalytic performance with high Faradaic efficiencies(FE)of over 90%for formate at wide potentials from-0.7 to-1.2 V *** hydrogen electrode(RHE).Moreover,the reversible Zn-CO_(2) battery can be driven by Bi_(9)Cu_(1)/CC cathode with a largest power density of 1.4 mW·cm^(-2),and superior operating *** systematic characterizations and electrochemical results confirm that the improved catalytic active sites,the enhanced mass/charge transport and the optimal reaction kinetics of Bi nanosheet are realized for CO_(2)RR by Cu *** situ attenuated total reflection infrared(ATR-IR)result confirms the bimetallic Bi-Cu active sites prefer to follow the^(*)OCHO conversion *** density functional theory(DFT)calculations suggest that the Cu alloying contributes to the increased density of states near the Fermi surface of Bi and the optimized adsorption of^(*)OCHO intermediates on the Bi sites,resulting in the excellent catalytic performance.

关键词： electronic regulation bismuth nanosheet copper alloying CO_(2)electroreduction Zn-CO_(2)batteries

Elevational and temporal patterns of pollination success in distylous and homostylous buckwheats(Fagopyrum)in the Hengduan Mountains

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Plant Diversity 2024年第5期46卷 661-670页

作者： Ling-yun wu Shuang-Quan Huang Ze-Yu Tong Faculty of Resources and Environmental Science Hubei UniversityWuhan 430062China Institute of Evolution and Ecology School of Life SciencesCentral China Normal UniversityWuhan 430079China

Reproductive strategies of sexually dimorphic plants vary in response to the ***,we ask whether the sexual systems of Fagopyrum species(i.e.,selfing homostylous and out-crossing distylous)represent distinct adaptive strategies to increase reproductive success in changing alpine *** answer this question,we determined how spatial and temporal factors(e.g.,elevation and peak flowering time)affect reproductive success(i.e.,stigmatic pollen load)in nine wild Fagopyrum species(seven distylous and two homostylous)among 28 populations along an elevation gradient of 1299-3315 m in the Hengduan Mountains,southwestern *** also observed pollinators and conducted hundreds of hand pollinations to investigate inter/intra-morph compatibility,self-compatibility and pollen limitation in four Fagopyrum species(two distylous and two homostylous).We found that Fagopyrum species at higher elevation generally had bigger flowers and more stigmatic pollen loads;lateflowering individuals had smaller flowers and lower pollen *** pollen deposition was more variable in distylous species than in homostylous *** seed set was not pollenlimited in all species,we found that fruit set was much lower in distylous species,which rely on frequent pollinator visits,than in homostylous species capable of autonomous *** findings that pollination success increases at high elevations and decreases during the flowering season suggest that distylous and homostylous species have spatially and temporally distinct reproductive strategies related to environment-dependent pollinator activity.

关键词： Biodiversity hotspot Elevation gradient Fagopyrum Stigmatic pollen load Temporal pattern

Infiltration,runoff,and slope stability behaviors of infinite slope with macropores based on an improved Green–Ampt model

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Journal of Mountain Science 2024年第7期21卷 2220-2235页

作者： LI Shanghui wu Guoxiong QUE yun JIANG Zhenliang CHENG Gaoyun College of Intelligent Construction Fuzhou University of International Studies and TradeFuzhou 350202China College of Civil Engineering Chongqing Jiao Tong UniversityChongqing 400074China Chongqing Vocational College of Architectural Engineering Chongqing 400072China College of Civil Engineering Fuzhou UniversityFuzhou 350000China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyHong Kong 999077China T.Y.Lin International Engineering Consulting(China)Co.Ltd Chongqing 401120China

Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is *** paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation *** show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative *** wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall ***,macropores benefit the slope stability in the early rainfall but not in the *** flow does not occur initially but becomes pronounced with increasing rainfall *** equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore *** analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows ***,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h.

关键词： Macropore slope Green–Ampt infiltration model Equivalent wetting front Ponding response time Slope stability