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Empirical estimates of regional carbon budgets imply reduced global soil heterotrophic respiration

National science Review 2021年第2期8卷 60-73页

作者： Philippe Ciais Yitong Yao Thomas Gasser Alessandro Baccini Yilong Wang Ronny Lauerwald Shushi Peng Ana Bastos Wei Li Peter A.Raymond Josep G.Canadell Glen P.Peters Rob J.Andres Jinfeng Chang Chao Yue A.Johannes Dolman Vanessa Haverd Jens Hartmann Goulven Laruelle Alexandra G.Konings Anthony W.King Yi Liu Sebastiaan Luyssaert Fabienne Maignan Prabir K.Patra Anna Peregon Pierre Regnier Julia Pongratz Benjamin Poulter Anatoly Shvidenko Riccardo Valentini Rong Wang Grégoire Broquet Yi Yin Jakob Zscheischler Bertrand Guenet Daniel S.Goll Ashley-P.Ballantyne Hui Yang Chunjing Qiu Dan Zhu State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University CSIRO Oceans and Atmosphere 15. Institute for Geology CEN—Center for Earth System Research and SustainabilityUniversity of Hamburg 16. Department of Earth System ScienceStanford University 17. Department of Earth System ScienceStanford UniversityStanford 18. School of Geographical SciencesNanjing University of Information Science and Technology 19. Department of Ecological SciencesVrije Universiteit Amsterdam 20. Research Institute for Global ChangeJAMSTEC Laboratoire des Sciences du Climat et de l'Environnement CEA-CNRS-UVSQ-UPSACLAY Center for Environmental Remote Sensing Chiba University Institute of Soil Science and Agrochemistry Siberian Branch of the Russian Academy of Sciences (SB RAS) Tuva State University Republic of Tuva Max Planck Institute for Meteorology NASA Goddard Space Flight Center Biospheric Sciences Lab. 26. Department for Innovation in BiologicalAgro-food and Forest systems (DIBAF)University of Tuscia RUDN University Department of Environmental Science and Engineering Shanghai Key Laboratory of Atmospheric Particle Pollution and PreventionInstitute of Atmospheric SciencesFudan University 29. Division of Geological and Planetary SciencesCalifornia Institute of Technology 30. Climate and Environmental Physics and Oeschger Centre for Climate Change ResearchUniversity of Bern 31. Department of Ecosystem and Conservation Sci

Resolving regional carbon budgets is critical for informing land-based mitigation policy. For nine regions covering nearly the whole globe, we collected inventory estimates of carbon-stock changes complemented by satellite estimates of biomass changes where inventory data are missing. The net land–atmospheric carbon exchange(NEE) was calculated by taking the sum of the carbon-stock change and lateral carbon fluxes from crop and wood trade, and riverine-carbon export to the ocean. Summing up NEE from all regions, we obtained a global ‘bottom-up’ NEE for net land anthropogenic CO2uptake of –2.2 ± 0.6 Pg C yr-1consistent with the independent top-down NEE from the global atmospheric carbon budget during 2000–2009. This estimate is so far the most comprehensive global bottom-up carbon budget accounting, which set up an important milestone for global carbon-cycle studies. By decomposing NEE into component fluxes, we found that global soil heterotrophic respiration amounts to a source of CO2of 39 Pg C yr-1with an interquartile of 33–46 Pg C yr-1—a much smaller portion of net primary productivity than previously reported.

关键词： carbon budget human appropriation of ecosystems soil carbon

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Modeling of service correlation for service composition in cloud manufacturing 31

Modeling of service correlation for service composition in c...

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31st European Modeling and simulation Symposium, EMSS 2019

作者： Wang, Fei Laili, Yuanjun Zhang, Lin Xing, Chi Guo, Liqin School of Automation Science and Electrical Engineering Beihang University China Beijing Complex Product Advanced Manufacturing Engineering Research Center Beijing Simulation Center China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System Engineering Beijing Simulation Center China Science and Technology on Space System Simulation Laboratory Beijing Simulation Center China

ISBN: (纸本)9788885741263

Cloud manufacturing (CMfg), integrating distributed manufacturing resources as services to cloud center, aims at intelligent, green, and economic customized manufacturing. The optimal composition of services to fulfill particular manufacturing requirement is a core issue to realize efficient cloud manufacturing. Many researchers have studied the problem considering the Quality-of-Service (QoS) of independent services. However, the correlation between services is rarely considered. In this paper, the importance of service correlation is emphasized. Two kinds of service correlation, service exclusion and service collaboration, are modeled for service composition. An improved algorithm DET, which combines Differential Evolution Algorithm (DE) with a Tabu table based on service exclusive and collaborative relationships, is designed to filter composable services and find better solutions for complex tasks. Experiments have shown the effects of service correlation on the quality of composed services and demonstrated the effectiveness of the proposed method DET compared with traditional DE. © 2019 Dime Universita di Genova, DIMEG University of Calabria.

关键词： Quality of service

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An 8-Channel RF Coil based on Microstrip Yagi-antenna for 7T Magnetic Resonance Imaging

An 8-Channel RF Coil based on Microstrip Yagi-antenna for 7T...

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IEEE International Symposium on Antennas and Propagation

作者： Ke He Mengxia Yu E Zhao Guiping Li Maoyan Wang Jing Ma School of Physics University of Electronic Science and Technology of China (UESTC) Chengdu China Science and Technology on Special System Simulation Laboratory Beijing China

ISBN: (数字)9781728166704

ISBN: (纸本)9781728166704;9781728166711

A new RF coil based on microstrip Yagi-antenna for 7T magnetic resonance imaging (MRI) is presented in this paper. The RF coil element consists of a driver which is a pair of dipoles printed on the dielectric substrate and two reflectors distributed on either sides of the driver. simulation results show that the proposed 8-channel RF coil array with these elements has high magnetic field intensity and uniform magnetic field distribution in the transverse plane, and can also maintain relatively low specific absorption rate (SAR) in the human body electromagnetic model. In addition, by comparing the RF field distribution of healthy organs and diseased organs, the feasibility of 8-channel RF coil array for human body imaging in MRI system is confirmed.

关键词： Radio frequency Microstrip antenna arrays Magnetic resonance imaging Electromagnetic modeling Specific absorption rate Magnetic fields Microstrip

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A Multi-Objective Optimization Model for simulation-based Acquisition

A Multi-Objective Optimization Model for Simulation-based Ac...

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Symposium of Image, Signal Processing, and Artificial Vision (STSIVA)

作者： Xue Zhang Junjie Xue Junhua Zhou Guoqiang Shi Yan Yu School of Computer Science and Engineering Nanjing University of Science and Technology Nanjing China Beijing Complex Product Advanced Manufacturing Engineering Research Center Beijing Simulation Center Beijing China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System Engineering Beijing China Science and Technology on Space System Simulation Laboratory Beijing Simulation Center Beijing China

ISBN: (数字)9781728170862

ISBN: (纸本)9781728170879

Large-scale equipment presents the characteristics of technology-intensive, knowledge-intensive and complex, which brings high investment and high risk to equipment acquisition. This paper analyzes the various components of equipment acquisition to fully apply modeling and simulation technology to each stage of it. On the basis of multi-objective optimization theory, the objective function of the lowest risk and lowest cost of simulation-based acquisition (SBA) is proposed. Then establishing a multi-objective optimization model for simulation-based acquisition according to the corresponding constraints. The nondominated sorting genetic algorithm II (NSGA II) and multi-objective particle swarm optimization (MOPSO) algorithms are used to optimize the model, and the majority voting method is used for integration. The comparison of simulation examples proves that the multi-objective optimization model oriented to SBA designed in this paper can effectively realize the optimization of each objective of SBA under cost constraints. And the feasibility and efficiency of optimization solution are guaranteed.

关键词： Analytical models Linear programming Reliability Particle swarm optimization Optimization Sorting Investment

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Large-Scale Single Tree Information Extraction of Oil Palm in Malaysia Based on Sub-Meter Visible Light Satellite Images

SSRN

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SSRN 2024年

作者： Zhang, Sen Li, Nan Cui, Yaoping Dong, Jinwei Yu, Le Ran, Lishan Chen, Ziyue Niu, Jiqiang Yan, Wei Kanniah, Kasturi Devi Xiao, Xiangming Zhang, Yongguang Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions Henan University Ministry of Education Kaifeng475004 China College of Geography and Environmental Science Henan University Kaifeng475004 China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application International Institute for Earth System Sciences Nanjing University Nanjing210023 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Department of Earth System Science Ministry of Education Key Laboratory for Earth System Modeling Institute for Global Change Studies Tsinghua University Beijing100084 China Department of Geography The University of Hong Kong Pokfulam999077 Hong Kong State Key Laboratory of Earth Surface Processes and Resource Ecology College of Global Change and Earth System Science Beijing Normal University Beijing100875 China College of Geographic Sciences Xinyang Normal University Xinyang464000 China Department of Geoinformation Faculty of Built Environment & Surveying Universiti Teknologi Malaysia Johor Bahru81310 Malaysia Department of Microbiology and Plant Biology Center for Spatial Analysis University of Oklahoma NormanOK73019 United States College of Environment and Planning Faculty of Geoinformation and Real Estate

The distribution of specific tree species and single tree information can shift down the research scale of geography and ecology, bridging research from regional to local scales. However, efficiently and finely extracting the spatial distribution and single tree information for a tree species regionally has always been a challenge due to the constraints of data and algorithms. With sub-meter visible light satellite images (RGB bands) in 2021 to 2022, we constructed a novel method for extracting the spatial distribution and single tree information of oil palm across Malaysia, namely the Single Tree Extraction Method - Oil Palm (STEM-OP). We developed a graphic morphological algorithm based on gradient difference window detection to extract the spatial distribution of oil palms. Then, we proposed an algorithm of double ring sliding detection algorithm to identify the canopy texture features of single oil palm. Finally, an adaptive iterative erosion algorithm was employed to separate overlapping and adjacent canopies into single trees. The overall accuracy of both the spatial distribution and number of single oil palm extracted by STEM-OP exceeded 90%. Our study revealed that the total area of oil palm in Malaysia was 5.25 million hectares, with a total of 572.6 million trees and an average planting density of 109 palms per hectare. The STEM-OP addresses the computational inefficiencies of methods with training samples and limitations of satellite image bands. For the first time, our study extracts the refined spatial distribution of oil palm and obtains the planting density and single tree position on a national scale. All of these are of great value to the formulation of oil palm development policies and ecological protection measures. © 2024, The Authors. All rights reserved.

关键词： Morphology

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Revealing the Memory Effects of Climatic Factors on Global Vegetation Dynamics Using Explainable Ai

SSRN

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SSRN 2023年

作者： Hu, Zhen Zhou, Wenyu Liang, Xun Guan, Qingfeng Wen, Youyue Liao, Weilin Yan, Yuchao Han, Cuiyan School of Geography and Information Engineering China University of Geosciences Hubei Wuhan430078 China National Engineering Research Center of GIS China University of Geosciences Hubei province Wuhan430078 China South China Institute of Environmental Science Ministry of Ecology and Environment Guangzhou510535 China National Key Laboratory of Urban Ecological Environment Simulation and Protection Guangzhou510535 China Guangdong Key Laboratory for Urbanization and Geo-simulation School of Geography and Planning Sun Yat-sen University Guangzhou510275 China Institute of Carbon Neutrality Sino-French Institute for Earth System Science College of Urban and Environmental Sciences Peking University Beijing100871 China Wuhan HopeTop Technology Co. Ltd. Wuhan430223 China

Discovering how vegetation responds to climatic factors is critical for understanding terrestrial ecosystem dynamics and predicting future vegetation states. In this study, we employ Explainable Artificial Intelligence (XAI) to unravel the spatiotemporal patterns of vegetation across a global scale over 12 months. Our approach utilizes the Long Short-Term Memory (LSTM) model to capture pixel-level vegetation dynamics driven by climatic factors. By leveraging the Permutation Feature Importance (PFI) method, we unveil the spatial distribution and temporal variability of each climate factor's contribution as learned by LSTM. Our results demonstrate that considering the long-term memory effect significantly enhances the explanatory power of climate factors for vegetation ecosystems in high latitudes of the Northern Hemisphere (R2>0.8). Notably, solar radiation emerges as the dominant factor worldwide, governing vegetation growth in 71.78% of the research regions, followed by precipitation (16.56%) and temperature (11.66%) variations. Furthermore, we uncover that vegetation in terrestrial ecosystems exhibits heightened sensitivity to historical temperature from 9 to 12 months ago, historical precipitation in the last three months, and historical solar radiation from 6 to 8 months ago throughout the 12-month historical time series. These findings highlight the significant lag effect of climatic factors on vegetation greenness changes and contribute to a better understanding of the impact of global climate change on terrestrial ecosystems, facilitating the development of more effective response strategies. © 2023, The Authors. All rights reserved.

关键词： Vegetation

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Unsupervised Domain Adaptation Using Attention Network and New Loss Function

Journal of Network Intelligence

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Journal of Network Intelligence 2022年第3期7卷 704-718页

作者： Zhao, Li-Quan Zhou, Si-Ying Teng, Zi-Ming Jiang, Zi-Cong Jia, Yan-Fei Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China College of information and communication Jilin University Changchun130012 China Graduate school of Information Science and Electrical Engineering Kyushu University Fukuoka819-0395 Japan School of Electrical and Information Engineering Beihua University Jilin132013 China

An unsupervised domain adaptation method is proposed based on the step-wise adaptive feature norm method to improve transfer learning accuracy. The feature extraction network consists of channel attention and spatial attention modules, which en-hance feature extraction ability. To reduce the influence of dimension change on channel weight, a convolution layer with the same kernel size is used to replace the fully connected layer in the bottleneck layer used in the common channel attention module. In addition, a smooth loss function is also proposed. The curve of the proposed function is smoother than the L2 function that is the least square error function. The proposed function’s gradient changes more slowly than the L2 function. The proposed function is used as the activate function of classification prediction regression to reduce the risk of gradient explosion. Compared with a selection of existing methods (Resnet50, conditional domain adversarial networks method, deep adaptive network method, joint adaptation network method, domain adaptation neural network method, and stepwise adaptive feature norm method), the proposed transfer learning method has the highest accuracy than other methods on different datasets for all tasks. © 2022 Taiwan Ubiquitous Information CO LTD. All rights reserved.

关键词： Feature extraction

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Contrasting Trends and Drivers of Global Surface and Canopy Urban Heat Islands

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Geophysical Research Letters 2023年第15期50卷 e2023GL104661-e2023GL104661页

作者： Du, Huilin Zhan, Wenfeng Voogt, James Bechtel, Benjamin Chakraborty, T.C. Liu, Zihan Hu, Leiqiu Wang, Zhihua Li, Jiufeng Fu, Peng Liao, Weilin Luo, Ming Li, Long Wang, Shasha Huang, Fan Miao, Shiqi Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology International Institute for Earth System Science Nanjing University Nanjing China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing China Department of Geography Western University LondonON Canada Department of Geography Ruhr-University Bochum Bochum Germany Atmospheric Sciences and Global Change Division Pacific Northwest National Laboratory RichlandWA United States Department of Atmospheric Science University of Alabama in Huntsville HuntsvilleAL United States School of Sustainable Engineering and the Built Environment Arizona State University TempeAZ United States Center for Environment Energy and Economy HarrisburgPA United States Guangdong Key Laboratory for Urbanization and Geo-simulation School of Geography and Planning Sun Yat-sen University Guangzhou China

A comprehensive comparison of the trends and drivers of global surface and canopy urban heat islands (termed Is and Ic trends, respectively) is critical for better designing urban heat mitigation strategies. However, such a global comparison remains largely absent. Using spatially continuous land surface temperatures and surface air temperatures (2003–2020), here we find that the magnitude of the global mean Is trend (0.19 ± 0.006°C/decade, mean ± SE) for 5,643 cities worldwide is nearly six-times the corresponding Ic trend (0.03 ± 0.002°C/decade) during the day, while the former (0.06 ± 0.004°C/decade) is double the latter (0.03 ± 0.002°C/decade) at night. Variable importance scores indicate that global daytime Is trend is slightly more controlled by surface property, while background climate plays a more dominant role in regulating global daytime Ic trend. At night, both global Is and Ic trends are mainly controlled by background climate. © 2023. The Authors.

关键词： Surface properties

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Logarithm Radon-Fourier transform for high speed small target detection with atmospheric resistance effect

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Digital Signal Processing: A Review Journal 2025年 165卷

作者： Sun, Difeng Xu, He Wu, Zutang Li, Jin Wu, Youcao Li, Jianbing State Key Laboratory of Complex Electromagnetic Environmental Effects on Electronics and Information System College of Electronic Science and Technology National University of Defense Technology Changsha410073 China National Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear Technology Xi'an710024 China Academy of Military Science of the People's Liberation Army Beijing100071 China

Detecting high-speed, small targets in air is challenging due to their complex non-linear motion model and range migration effects. Traditional finite order polynomial models often fail to account for atmospheric drag accurately. This paper introduces a logarithmic relationship between range and time to model this motion, employing the Logarithmic Radon-Fourier Transform (LRFT) for accurately compensating the envelope and phase migration over extended accumulation periods. It offers both the ergodic search method and the fast implementation method for solving LRFT, along with a theoretical analysis of lobe location and amplitude. simulation results indicate that compared with traditional RFT-based methods, LRFT improves accumulation gain, enhances the main lobe's relative amplitude over sidelobes, and offers better detection performance in noisy environments. It provides more accurate recovery of target motion and improved target distinction capabilities. These benefits over traditional methods are especially evident when the product of the attenuation coefficient α, the initial velocity v0, and the total coherent accumulation time TM exceeds a specific threshold. © 2025 Elsevier Inc.

关键词： Fast Fourier transforms

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Research on evaluation method of cooperative jamming effect in cognitive confrontation 1st

Research on evaluation method of cooperative jamming effect ...

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1st EAI International Conference on Artificial Intelligence for Communications and Networks, AICON 2019

作者： Ma, Jing Shi, Bin Che, Fei Zhang, Sitong Science and Technology on Special System Simulation Laboratory Beijing100854 China Harbin Engineering University Harbin150001 China

ISBN: (纸本)9783030229702

In modern warfare, due to the increasingly complex electromagnetic environment, cognitive confrontation will become the main form of war. Effective interference with enemy radars is of great importance for taking the lead in the battlefield. The evaluation of the synergistic interference effect is an important indicator to measure the performance of the interference equipment. According to the evaluation result, the interference strategy can be changed in time to achieve the best interference revenue and provide a strong guarantee for the successful penetration of the target. In this paper, the discovery probability and positioning accuracy of radar network are used as evaluation indicators to establish an evaluation model. The interference power, interference frequency, interference timing and interference pattern are used as membership functions. The distance, false alarm probability and different interference strategies are studied. The simulation shows that proper false alarm probability, closer distance and proper interference strategy can improve the interference benefit and provide a theoretical basis for obtaining the best interference effect in the actual battlefield. © ICST Institute for Computer sciences, Social Informatics and Telecommunications Engineering 2019 Published by Springer Nature Switzerland AG 2019. All Rights Reserved.

关键词： Membership functions

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