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Biome reconstruction on the Tibetan Plateau since the Last Glacial Maximum using a machine learning method

Science China Earth Sciences 2022年第3期65卷 518-535页

作者： Feng QIN Yan ZHAO Xianyong CAO Key Laboratory ofLand Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Alpine Paleoecology and Human Adaptation(ALPHA)Group State Key Laboratory of Tibetan Plateau Earth System Science(LATPES)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Historical biome changes on the Tibetan Plateau provide important information that improves our understanding of the alpine vegetation responses to climate ***,a comprehensively quantitative reconstruction of the historical Tibetan Plateau biomes is not possible due to the lack of quantitative methods that enable appropriate classification of alpine biomes based on proxy data such as fossil pollen *** this study,a pollen-based biome classification model was developed by applying a random forest algorithm(a supervised machine learning method)based on modern pollen assemblages on and around the Tibetan Plateau,and its robustness was assessed by comparing its results with the predictions of the biomisation *** results indicated that modern biome distributions reconstructed using the random forest model based on modern pollen data generally concurred with the observed zonal *** random forest model had a significantly higher accuracy than the biomisation method,indicating the former is a more suitable tool for reconstructing alpine biome changes on the Tibetan *** random forest model was then applied to reconstruct the Tibetan Plateau biome changes from 22 ka BP to the present based on 51 fossil pollen *** reconstructed biome distribution changes on the Tibetan Plateau generally corresponded to global climate changes and Asian monsoon *** the Last Glacial Maximum,the Tibetan Plateau was mainly desert with subtropical forests distributed in the *** the last deglaciation,the alpine steppe began expanding and gradually became zonal vegetation in the central and eastern *** meadow occupied the eastern and southeastern areas of the Tibetan Plateau since the early Holocene,and the forest-meadow-steppe-desert pattern running southeast to northwest on the Tibetan Plateau was established *** the mid-Holocene,subtropical forests extended north,which reflected the“optimum”***

关键词： Biome reconstruction Random forest algorithm Biomisation method Pollen data Last Glacial Maximum Tibetan Plateau

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Target-driven Object Grasping Method for Mobile Manipulator in Clutter

Target-driven Object Grasping Method for Mobile Manipulator ...

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2022 IEEE International Conference on Unmanned systems, ICUS 2022

作者： Yu, Xinkai Gao, Yongzhuo Dong, Wei Li, Mingyang Liu, Huajian Wang, Chao Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China Beijing Institute of Control Engineering Beijing China

ISBN: (数字)9781665484565

ISBN: (纸本)9781665484565

The demand for mobile manipulator in the military field is strong, but there is no product that can achieve autonomous grasping in a cluttered environment. In this paper, a target-driven grasp pose detection algorithm is proposed, which can be used to detect the grasp pose of a specified target object in a cluttered environment. After that, based on the lightweight requirements of the military, a mobile manipulator platform is built, and the forward and inverse kinematics model of the mobile manipulator is established. At the same time, a vehicle-arm coordination algorithm is designed to make the grasping efficiency higher. Finally, we use the mobile manipulator to perform autonomous grasping in a cluttered environment to verify the system functionality. © 2022 IEEE.

关键词： Manipulators

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Speed sensorless control with neuron MRAS estimator of an induction machine

Speed sensorless control with neuron MRAS estimator of an in...

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7th International Conference on Power Electronics and Drive systems, PEDS 2007

作者： Lei, Dong Dong, Yang Xiaozhong, Liao Department of Automatic Control Engineering Beijing Institute of Technology Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education Beijing China

ISBN: (纸本)1424406455

In the high speed range, vector control of rotor flux orientation of an induction machine implements good performance. However, the performance in low speed rang deteriorates because of the inaccurate estimation of rotor flux and speed. In this paper, modified voltage model for rotor flux estimation and neuron model-reference adaptive system (MRAS) for speed estimation are used to improve the performance of speed sensorless vector control. To improve the accuracy of rotor flux estimation, the stator resistance is identified on-line. The experimental results show that the proposed scheme yields improved performance in low speed range. © 2007 IEEE.

关键词： Induction machine

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Evaluating CMIP6 models in simulating the North Pacific decadal variability in sea surface salinity

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Science China Earth Sciences 2024年第8期67卷 2661-2680页

作者： Jian CHEN Hailong LIU Pengfei LIN Wenrong BAI Chengzu BAI Lu WANG Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China State Key Laboratory of Geo-Information Engineering Xi’an 710054China Beijing Municipal Climate Center Beijing Meteorological BureauBeijing 100089China Space System Department Equipment Department Beijing 100096China

The North Pacific sea surface salinity(SSS)decadal variability(NPSDV)and its potential forcing were evaluated from 25 coupled models of the Coupled Model Intercomparison Project phase 6(CMIP6)considering the prospects for decadal climate *** results indicated that the CMIP6 models generally reproduced the spatial patterns of *** large standard deviation of the SSS anomaly over the strong current regions,such as the Kuroshio-Oyashio Extension(KOE),North Pacific Current(NPC),California Current system(CCS),and Alaskan Coastal Current(ACC),is reflected in the two leading modes of NPSDV:a dipole with out-of-phase loadings in the KOE-NPC versus CCS-ACC and a monopole with positive loading over the *** order of modes is sensitive to individual models that exhibit discrepancies,especially in temporal phases and power *** autoregressive model of order-1 was used to reconstruct the NPSDV with several forcing *** generally weaker influence of forcings in an autoregressive model of order-1 is partly related to the overestimated response time of NPSDV relative to *** NPSDV variances originate from the persistence of SSS anomalies,but the dominant forcing factors are diverse among *** model diversity for the NPSDV simulation mainly arises from the influence of the tropical El Ni?o-Southern Oscillation through teleconnection on the North Pacific Oscillation or Aleutian Low with timescale ***,models that can reproduce the NPSDV well are not dependent on those with larger impacts from the North Pacific oceanic processes.

关键词： North Pacific Sea surface salinity Decadal variability CMIP6 Leading mode

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Target Assignment Optimization of Heterogeneous Sensor Networks in Urban Environment 39

Target Assignment Optimization of Heterogeneous Sensor Netwo...

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39th Chinese Control Conference, CCC 2020

作者： Chen, Chen Zihao, Cheng Wei, Xu Beijing Institute of Technology School of Automation Beijing100081 China State Key Laboratory of Intelligent Control and Decision of Complex System Beijing100081 China

ISBN: (纸本)9789881563903

Preventing and controlling Low-Slow-Small(LSS) targets are problems to be solved due to their good concealment in urban environment. Consequently, the problem of target assignment is studied in this paper. Firstly, a target assignment model based on heterogeneous sensor networks is proposed. The characteristics of LSS targets and the influence of environmental factors such as climate and terrain are considered on this model. At the same time, the detection capabilities of different detection nodes and collaborative tracking capabilities are also considered. Secondly, an intelligent optimization algorithm GSAPSO based on PSO is proposed to maximize tracking effect of the sensors. Finally, the simulations are used to compare the GSAPSO algorithm with the traditional PSO and GAPSO algorithms. The results demonstrate that the proposed algorithm has better tracking effect. © 2020 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Particle swarm optimization (PSO)

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Network-based humanoid robot remote interaction with the actual situation Fusion Technology

Network-based humanoid robot remote interaction with the act...

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The 2011 International Conference on Advanced Materials and Information Technology Processing(AMITP 2011)

作者： YU Guochen WANG Zhiliang XIE Lun XU Jiaming State Key Laboratory of Robotics and System Harbin Institute of Technology School of Computer and Communication Engineering University of Science and Technology Beijing

ISBN: (纸本)9783037851579

With the rapid development of network technology, network-based humanoid robot technology will also be open to the development of gradual and orderly progress. This article is based on the C / S architecture, the server responsible for controlling the record of news and information network transit between paragraphs;through remote interaction, real-time client to complete the real humanoid robot control functions. Interoperability between the client, first to sign the server. Server information of all registered users to return to the client process, then the client users will be able to get online users to select the remote robot interaction..When a user operation, the client program as a virtual robot through the virtual robot laboratory will be displayed in realtime robot control results.

关键词： Humanoid robot,remote interactive,virtual,real-time,network

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An Intelligent simulation Result Validation Method Based on Variational Autoencoder 23rd

An Intelligent Simulation Result Validation Method Based on ...

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23rd Asia simulation Conference, AsiaSim 2024

作者： Yang, Fan Ma, Ping Li, Wei Tao, Chao Yang, Ming Zhang, Jianchao Cheng, Huichuan Control and Simulation Center Harbin Institute of Technology Harbin150080 China National Key Laboratory of Complex System Modeling and Simulation Harbin150080 China Chinese Aeroengine Research Institute Beijing101304 China

ISBN: (纸本)9789819772247

Validation for complex system simulation faces the challenges of a large amount of validation data, which comes in the form of extensive samples and prolonged time series. To address this issue, this paper proposes an intelligent simulation result validation method based on Variational Autoencoder (VAE), achieving model validation through intelligent feature extraction and feature consistency metrics. Initially, we present the overall validation framework, which consists of feature extraction and simulation result validation, and detail the steps of the validation process. Subsequently, the principles and procedures of the feature extraction and simulation result validation methods are thoroughly discussed. The feature extraction is achieved by learning the distribution parameters of the latent space using a VAE model. Feature differences across various aspects are measured by three distance metrics and are further converted into simulation credibility. Finally, the effectiveness and superiority of this method are demonstrated through a case study on validating a drone delivery model. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Digital elevation model

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Research and Implementation of Model engineering Environment Integration Based on OpenMBEE 21st

Research and Implementation of Model Engineering Environment...

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21st Asia simulation Conference, AsiaSim 2022

作者： Xue, Junjie Zhou, Junhua Shi, Guoqiang Feng, Chaoqun Xu, Lin Liu, Penghua Quan, Hongyan Engineering Research Center Beijing Simulation Center Beijing100854 China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System Engineering Beijing100854 China Science and Technology on Space System Simulation Laboratory Beijing Simulation Center Beijing100854 China Yunnan Chensheng Tendering Consulting Co. Ltd. Kuming650102 China School of Computer Science and Technology East China Normal University Shanghai200062 China

ISBN: (纸本)9789811991974

Aiming at the problem of integrating open tools in a user development environment in complex product design, an integration strategy of model engineering environment based on OpenMBEE is studied. It is based on the technologies of user identity unified authentication and user interaction data collaboration. Specifically, in the solution of unified identity authentication on cross-platform, the extended controller method is provided based on the message queue information flow mechanism. Then, the separation of business logic, data information, and interactive view of user unified authentication are realized, on the basis, that the function of unified identity authentication is realized by using the Software Development Kit (SDK) of OpenMBEE. Besides, in the study of user interaction data collaboration technology, three-layer collaboration mechanisms are proposed, they are the presentation layer collaboration, the business layer collaboration, and the persistence layer collaboration. When the jQuery programming framework is integrated into the bootstrap front-end framework, combing with the OpenMBEE back-end server interface, the collaboration of user interaction data is realized. Through experiments and project practice analysis, the user unified authentication strategy and user interactive collaboration strategy are tested respectively for proving the effectiveness and feasibility of the proposed method. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Authentication

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An Intelligent Ranking Evaluation Method of simulation Models Based on Graph Neural Network 15th

An Intelligent Ranking Evaluation Method of Simulation Model...

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15th EAI International Conference on simulation Tools and Techniques, SIMUTools 2023

作者： Yang, Fan Ma, Ping Zhang, Jianchao Cheng, Huichuan Li, Wei Yang, Ming Control and Simulation Center Harbin Institute of Technology Harbin150080 China National Key Laboratory of Complex System Modeling and Simulation Harbin150080 China Chinese Aeroengine Research Institute Beijing101304 China

ISBN: (纸本)9783031575228

To validate the alternative simulation models and select the most credible one when the models have multivariate and correlated outputs, an intelligent ranking evaluation method of simulation models based on Graph Neural Network (GNN) is proposed. The process of ranking evaluation is divided into three parts: graph structure conversion for evaluation data, feature extraction based on Graph Representation Learning (GRL) and ranking evaluation based on feature distance. A graph structure modeling method is presented to provide the pre-define graph structure for further GRL primarily. Next the interdependencies and dynamic evolutionary patterns among variables are captured by GNN so that the graph representations of evaluation data can be obtained. Then ranking evaluation is achieved by similarity measurement of the graph representations. In the end, the effectiveness of the proposed method on feature extraction of evaluation data and simulation models ranking is illustrated through an application example on a prediction model for aerodynamic parameters of a certain flight vehicle. © ICST institute for Computer Sciences, Social Informatics and Telecommunications engineering 2024.

关键词： Feature extraction

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Molecular dynamics simulation of a single polymer in hydrophilic nano-slits

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Chinese Science Bulletin 2008年第17期53卷 2599-2606页

作者： REN Ying GAO Jian GE Wei LI JingHai HU GuoHua State Key Laboratory of Multiphase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100090 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China Laboratory of Chemical Engineering Sciences CNRS-ENSIC-INPL 1 rue Grandville BP 20451 Nancy 54001 France

The behavior of a single polyethylene polymer in aqueous solution confined between two hydrophilic walls is studied with molecular dynamics (MD) simulations. The thickness of the nano-slit ranges from 1.26 to 3.15 nm, which is comparative to the polymer dimension. A monotonic transition from 3D- to 2D-like configurations is observed as the distance between the two walls narrows. Monomers are compressed into several layers and the preferred bond orientations alternate between parallel and normal to the walls accordingly. The diffusivity in the direction parallel to the wall is always larger than the one perpendicular to it. Calculation of the entropy and enthalpy changes during the folding of the polymer chain alone cannot explain the spontaneous process. The corresponding increase in water entropy due to volume expansion may be large enough to result in the overall free energy decrease.

关键词：聚乙烯聚合体分子动力学模拟亲水性纳米裂缝

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