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Dynamic ocean inverse modeling based on differentiable rendering

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Computational Visual Media 2024年第2期10卷 279-294页

作者： Xueguang xie yang Gao Fei Hou Aimin Hao Hong qin State Key Lab of Virtual Reality Technology and Systems Beihang UniversityBeijing 100191China qingdao Research Institute Beihang UniversityQingdao 266100Chinaand Peng Cheng LabShenzhen 518000China SKLCS Institute of SoftwareChinese Academy of SciencesBeijing 100190Chinaand University of Chinese Academy of SciencesBeijing 100049China Department of Computer Science Stony Brook University(SUNY at Stony Brook)Stony BrookNew York 11794-2424USA

Learning and inferring underlying motion patterns of captured 2D scenes and then re-creating dynamic evolution consistent with the real-world natural phenomena have high appeal for graphics and *** bridge the technical gap between virtual and real environments,we focus on the inverse modeling and reconstruction of visually consistent and property-verifiable oceans,taking advantage of deep learning and differentiable physics to learn geometry and constitute waves in a self-supervised ***,we infer hierarchical geometry using two networks,which are optimized via the differentiable *** extract wave components from the sequence of inferred geometry through a network equipped with a differentiable ocean ***,ocean dynamics can be evolved using the reconstructed wave *** extensive experiments,we verify that our new method yields satisfactory results for both geometry reconstruction and wave ***,the new framework has the inverse modeling potential to facilitate a host of graphics applications,such as the rapid production of physically accurate scene animation and editing guided by real ocean scenes.

关键词： inverse modeling surface reconstruction wave modeling ocean waves differentiable rendering(DR)

Dynamic SLAM Visual Odometry Based on Instance Segmentation:A Comprehensive Review

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Computers, Materials & Continua 2024年第1期78卷 167-196页

作者： Jiansheng peng qing yang Dunhua Chen Chengjun yang Yong Xu Yong qin College of Automation Guangxi University of Science and TechnologyLiuzhou545000China Department of Artificial Intelligence and Manufacturing Hechi UniversityHechi547000China

Dynamic Simultaneous Localization and Mapping(SLAM)in visual scenes is currently a major research area in fields such as robot navigation and autonomous ***,in the face of complex real-world envi-ronments,current dynamic SLAM systems struggle to achieve precise localization and map *** the advancement of deep learning,there has been increasing interest in the development of deep learning-based dynamic SLAM visual odometry in recent years,and more researchers are turning to deep learning techniques to address the challenges of dynamic *** to dynamic SLAM systems based on deep learning methods such as object detection and semantic segmentation,dynamic SLAM systems based on instance segmentation can not only detect dynamic objects in the scene but also distinguish different instances of the same type of object,thereby reducing the impact of dynamic objects on the SLAM system’s *** article not only introduces traditional dynamic SLAM systems based on mathematical models but also provides a comprehensive analysis of existing instance segmentation algorithms and dynamic SLAM systems based on instance segmentation,comparing and summarizing their advantages and *** comparisons on datasets,it is found that instance segmentation-based methods have significant advantages in accuracy and robustness in dynamic ***,the real-time performance of instance segmentation algorithms hinders the widespread application of dynamic SLAM *** recent years,the rapid development of single-stage instance segmentationmethods has brought hope for the widespread application of dynamic SLAM systems based on instance ***,possible future research directions and improvementmeasures are discussed for reference by relevant professionals.

关键词： Dynamic SLAM instance segmentation visual odometry

A quasi-zero stiffness energy harvesting isolator with triple negative stiffness

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Acta Mechanica Sinica 2024年第8期40卷 219-238页

作者： Xiangyu Cai Tao yang Weiyang qin Zhongliang xie Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518057China Department of Engineering Mechanics Northwestern Polytechnical UniversityXi’an710072China

Vibration isolation for low frequency excitation and the power supply for low power monitoring sensors are important issues in bridge *** main problem is how to effectively combine the vibration isolator with the energy harvester to form a multi-functional *** this paper,a system called quasi-zero stiffness energy harvesting isolator(QZS-EHI)with triple negative stiffness(TNS)is *** TNS structure consists of linear springs,rigid links,sliders,and ring permanent ***’s second law and Kirchhoff’s law construct dynamic equations of the QZS-EHI,and a comparison is made to contrast it with other QZS and linear *** comparison field includes the QZS range,amplitude-frequency relationship,force transmissibility,and energy harvested *** isolator can be applied to many engineering fields such as bridges,automobiles,and railway *** paper selects bridge engineering as the main field for the dynamic analysis of this *** the multi-span beam bridge,this paper compares different situations including the bridge with QZS-EHI support,with linear stiffness isolator support,and with single beam *** results show that the QZS-EHI is not only better than the traditional isolator with linear stiffness under both harmonic and stochastic excitation,but also better than some QZS isolators with double or single negative stiffness in bridge vibration isolation and energy *** analysis is verified to correspond to the simulation analysis,which means the proposed QZS-EHI has practical application value.

关键词： Quasi-zero stiffness Triple negative stiffness Vibration isolation Energy harvesting

Full waveform inversion based on hybrid gradient

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Petroleum Science 2024年第3期21卷 1660-1670页

作者： Chuang xie Zhi-Liang qin Jian-Hua Wang peng Song Heng-Guang Shen Sheng-Qi Yu Ben-Jun Ma Xue-qin Liu qingdao Innovation and Development Base Harbin Engineering UniversityQingdao266000ShandongChina qingdao Innovation and Development Center Harbin Engineering UniversityQingdao266000ShandongChina CNOOC Research Institute Co. Ltd.Beijing100028China College of Marine Geoscience Ocean University of ChinaQingdao266100ShandongChina Weihai Sunfull Geophysical Exploration Equipment Co. Ltd.Weihai264209ShandongChina

The low-wavenumber components in the gradient of full waveform inversion(FWI)play a vital role in the stability of the ***,when FWI is implemented in some high frequencies and current models are not far away from the real velocity model,an excessive number of low-wavenumber components in the gradient will also reduce the convergence rate and inversion *** solve this problem,this paper firstly derives a formula of scattering angle weighted gradient in FWI,then proposes a hybrid *** hybrid gradient combines the conventional gradient of FWI with the scattering angle weighted gradient in each inversion frequency band based on an empirical formula derived *** weighted hybrid mode,we can retain some low-wavenumber components in the initial lowfrequency inversion to ensure the stability of the inversion,and use more high-wavenumber components in the high-frequency inversion to improve the convergence *** results of synthetic data experiment demonstrate that compared to the conventional FWI,the FWI based on the proposed hybrid gradient can effectively reduce the low-wavenumber components in the gradient under the premise of ensuring inversion *** also greatly enhances the convergence rate and inversion accuracy,especially in the deep part of the *** the field marine seismic data experiment also illustrates that the FWI based on hybrid gradient(HGFWI)has good stability and adaptability.

关键词： Full waveform inversion Hybrid gradient Scattering angle weighted Low-wavenumber component

Hydroxylated metal–organic-layer nanocages anchoring single atomic cobalt sites for robust photocatalytic CO_(2) reduction

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Nano Research 2024年第4期17卷 2410-2419页

作者： Weiyi Pan Zhihe Wei Yanhui Su Yuebin Lian Zhangyi Zheng Huihong Yuan Yongze qin Xulan xie Qianqian Bai Zhenyang Jiao Wei Hua Jinzhou Chen Wenjun yang Zhao Deng yang peng Soochow Institute for Energy and Materials Innovations College of EnergySoochow UniversitySuzhou 215006China Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province Soochow UniversitySuzhou 215006China School of Photoelectric Engineering Changzhou institute of technologyChangzhou 213032China Jiangsu Key Laboratory for Advanced Negative Carbon Technologies Soochow UniversitySuzhou 215123China

Assembly of two-dimensional(2D)metal–organic layers(MOLs)based on the hard and soft acid–base theorem represents an exquisite strategy for the construction of photocatalytic platforms in virtue of the highly exposed active sites,much improved mass transport,and greatly elevated ***,nanocages composed of MOLs are produced for the first time through a cosolvent approach utilizing zirconium-based UiO-66-(OH)2 as the structural *** endow the catalytic activity for CO_(2) conversion,single atomic Co^(2+)sites are appended to the Zr-oxo nodes of the MOL cages,demonstrating a remarkable CO yield of 7.74 mmol·g^(-1)·h^(-1) and operational stability of 97.1%product retention after five repeated *** an outstanding photocatalytic performance is mainly attributed to the unique nanocage morphology comprising enormous 2D nanosheets for augmented Co^(2+)exposure and the abundant surface hydroxyl groups for local CO_(2) *** work underlines the tailoring of both metal–organic framework(MOF)morphology and functionality to boost the turnover rate of photocatalytic CO_(2) reduction reaction(CO_(2)RR).

关键词： photocatalytic CO_(2) reduction metal–organic layer nanocage single-atom catalyst co-catalyst

Standardized Volume Power Density Boost in Frequency-Up Converted Contact-Separation Mode Triboelectric Nanogenerators

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Research 2024年第2期2023卷 691-702页

作者： Zhongjie Li Chao yang qin Zhang Geng Chen Jingyuan Xu Yan peng Hengyu Guo School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444P.R.China Institute of Artificial Intelligence Shanghai UniversityShanghai 200444P.R.China National Engineering Research Center of Turbo-Generator Vibration School of Energy and EnvironmentSoutheast UniversityNanjing 210096P.R.China institute of Microstructure Technology Karlsruhe Institute of TechnologyKarlsruhe 76344Germany Shanghai Artificial Intelligence Laboratory Shanghai 200444P.R.China Department of Applied Physics Chongqing UniversityChongqing 400044P.R.China

The influence of a mechanical structure's volume increment on the volume power density (VPD) of triboelectric nanogenerators (TENGs) is often neglected when considering surface charge density and surface power density. This paper aims to address this gap by introducing a standardized VPD metric for a more comprehensive evaluation of TENG performance. The study specifically focuses on 2 frequency-up mechanisms, namely, the integration of planetary gears (PG-TENG) and the implementation of a double-cantilever structure (DC-TENG), to investigate their impact on VPD. The study reveals that the PG-TENG achieves the highest volume average power density, measuring at 0.92 W/m^(3). This value surpasses the DC-TENG by 1.26 times and the counterpart TENG by a magnitude of 69.9 times. Additionally, the PG-TENG demonstrates superior average power output. These findings introduce a new approach for enhancing TENGs by incorporating frequency-up mechanisms, and highlight the importance of VPD as a key performance metric for evaluating TENGs.

关键词： increment neglected considering

Adaptation analysis and fusion correction method of CMIP6 precipitation simulation data on the qinghai-Tibetan Plateau

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Journal of Mountain Science 2024年第2期21卷 555-573页

作者： peng Hao qin Dahui WANG Zegen ZHANG Menghan yang Yanmei YONG Zhiwei School of Civil Engineering and Geomatics Southwest Petroleum UniversityChengdu 610500China School of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China

In order to obtain more accurate precipitation data and better simulate the precipitation on the Tibetan Plateau,the simulation capability of 14 Coupled Model Intercomparison Project Phase 6(CMIP6)models of historical precipitation(1982-2014)on the qinghai-Tibetan Plateau was evaluated in this *** indicate that all models exhibit an overestimation of precipitation through the analysis of the Taylor index,temporal and spatial statistical *** correct the overestimation,a fusion correction method combining the Backpropagation Neural Network Correction(BP)and Quantum Mapping(QM)correction,named BQ method,was *** this method,the historical precipitation of each model was corrected in space and time,*** correction results were then analyzed in time,space,and analysis of variance(ANOVA)with those corrected by the BP and QM methods,***,the fusion correction method results for each model were compared with the Climatic Research Unit(CRU)data for significance analysis to obtain the trends of precipitation increase and decrease for each *** results show that the IPSL-CM6A-LR model is relatively good in simulating historical precipitation on the qinghai-Tibetan Plateau(R=0.7,RSME=0.15)among the uncorrected *** terms of time,the total precipitation corrected by the fusion method has the same interannual trend and the closest precipitation values to the CRU data;In terms of space,the annual average precipitation corrected by the fusion method has the smallest difference with the CRU data,and the total historical annual average precipitation is not significantly different from the CRU data,which is better than BP and ***,the correction effect of the fusion method on the historical precipitation of each model is better than that of the QM and BP *** precipitation in the central and northeastern parts of the plateau shows a significant increasing *** correlation coefficients between monthly

关键词： GCM CMIP6 Precipitation correction BP-QM fusion correction Spatio-temporal characteristics

Westerlies Affecting the Seasonal Variation of Water Vapor Transport over the Tibetan Plateau Induced by Tropical Cyclones in the Bay of Bengal

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Advances in Atmospheric Sciences 2024年第5期41卷 881-893页

作者： Xiaoli ZHOU Wen ZHOU Dongxiao WANG Qiang xie Lei yang Qihua peng Key Laboratory of Polar Atmosphere-ocean-ice System for Weather and Climate Ministry of Education&Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric SciencesFudan UniversityShanghai 200438China School of Marine Sciences Sun Yat-Sen UniversityZhuhai 519082China Institute of Deep-sea Science and Engineering Chinese Academic SciencesSanya 572000China State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academic ScienceGuangzhou 510301China Scripps Institution of Oceanography University of CaliforniaSan DiegoLa JollaCalifornia 92093USA

This study investigates the activity of tropical cyclones(TCs)in the Bay of Bengal(BOB)from 1979 to 2018 to discover the mechanism affecting the contribution rate to the meridional moisture budget anomaly(MMBA)over the southern boundary of the Tibetan Plateau(SBTP).May and October–December are the bimodal phases of BOB TC frequency,which decreases month by month from October to December and is relatively low in ***,the contribution rate to the MMBA is the highest in *** seasonal variation in the meridional position of the westerlies is the key factor affecting the contribution *** relatively southern(northern)position of the westerlies in November and December(May)results in a lower(higher)contribution rate to the *** mechanism is confirmed by the momentum *** water vapor enters the westerlies near the trough line,the resultant meridional acceleration is directed *** follows that the farther north the trough is,and the farther north the water vapor can be *** water vapor enters the westerlies from the area near the ridge line,for Type-T(Type-R)TCs,water vapor enters the westerlies downstream of the trough(ridge).Consequently,the direction of the resultant meridional acceleration is directed south and the resultant zonal acceleration is directed east(west),which is not conducive to the northward transport of water *** is especially the case if the trough or ridge is relatively south,as the water vapor may not cross the SBTP.

关键词： tropical cyclone Tibetan Plateau Bay of Bengal moisture budget weste

Application of modified discontinuous deformation analysis to dynamic modelling of the Baige landslide in the Jinsha River

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Journal of Mountain Science 2024年第7期21卷 2305-2319页

作者： xie Chenxi DENG Jianhui peng Xinyan yang Zhongkang ZHAO Siyuan LI Hua State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610031China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610051China MOE Key Laboratory of Deep Earth Science and Engineering Institute for Disaster Management and ReconstructionSichuan UniversityChengdu 610031China Power China Chengdu Engineering Corporation Limited Chengdu 610031China

Accurate dynamic modeling of landslides could help understand the movement mechanisms and guide disaster mitigation and *** deformation analysis(DDA)is an effective approach for investigating ***,DDA fails to accurately capture the degradation in shear strength of rock joints commonly observed in high-speed *** this study,DDA is modified by incorporating simplified joint shear strength *** on the modified DDA,the kinematics of the Baige landslide that occurred along the Jinsha River in China on 10 October 2018 are *** violent starting velocity of the landslide is considered *** cases with different violent starting velocities are investigated to show their effect on the landslide movement ***,the landslide movement process and the final accumulation characteristics are analyzed from multiple *** results show that the violent starting velocity affects the landslide motion characteristics,which is found to be about 4 m/s in the Baige *** movement process of the Baige landslide involves four stages:initiation,high-speed sliding,impact-climbing,low-speed motion and *** accumulation states of sliding masses in different zones are different,which essentially corresponds to *** research results suggest that the modified DDA is applicable to similar high-level rock landslides.

关键词： Discontinuous deformation analysis(DDA) Baige landslide Violent starting velocity movement process Accumulation characteristics