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The Controller Design and Stability Analysis of Teleoperation Systems with Time Delay and without Velocity measurements

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The Controller Design and Stability Analysis of Teleoperatio...

Investigation of the influences of asphaltene deposition on oilfield development using reservoir simulation

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作者： Du Songnan LIU Bin College of information science and engineering Wuhan University of Science and Technology Engineering Research center for Metallurgical Automation and Detecting Technology of Ministry of Education Wuhan University of Science and Technology

ISBN: (纸本)9781538629185

For the multi-degree of freedom teleoperation under time-varying delays,a Proportional-Derivative（PD） like controller,without making use of velocity measurements,is improved in this paper.By choosing Lyapunov-Krasovskii functional,we show that the master-slave teleoperation system is stable under specific conditions.And with the given controller-design parameters,the proposed stability criteria can be used to compute the allowable maximal transmission delay.The results are also compared with the previous to prove its superiority under time-varying delays and finally the effectiveness of the proposed controller has been proved by the simulation of a typical mission.

关键词： time-varying delay teleoperation without velocity measurements Lyapunov-Krasovskii functional stability

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Petroleum Exploration and Development 2022年第5期49卷 1138-1149页

作者： TANANYKHIN D S STRUCHKOV I A KHORMALI A ROSCHIN P V Saint-Petersburg Mining University Saint-Petersburg 199106Russia LLC Tyumen Petroleum Research center Tyumen 625000Russia Department of Chemistry Faculty of Basic Sciences and EngineeringGonbad Kavous UniversityGonbad Kavous 49717-99151Iran LLC SamaraNIPIneft Samara 443010Russia

This paper investigates the deposition of asphaltenes in the porous medium of the studied field in Russia and predicts production profiles based on uncertainty evaluation. This problem can be solved by dynamic modeling, during which production profiles are estimated in two scenarios: with and without the activation of the asphaltene option. Calculations are carried out for two development scenarios: field operation under natural depletion and water injection into the aquifer as a reservoir pressure maintenance system. A full-scale compositional reservoir simulation model of the Russian oilfield was created. Within a dynamic simulation, the asphaltene option was activated and the asphaltene behavior in oil and porous medium was tuned according to our own special laboratory experiments. The model was also matched to production historical data, and a pattern model was prepared using the full-scale simulation model. Technological and the asphaltene option parameters were used in sensitivity and an uncertainty evaluation. Furthermore, probable production profiles within a forecast period were estimated. The sensitivity analysis of the pattern model to input parameters of the asphaltene option allowed determining the following heavy-hitters on the objective function: the molar weight of dissolved asphaltenes as a function of pressure, the asphaltene dissociation rate, the asphaltene adsorption coefficient and the critical velocity of oil movement in the reservoir. Under the natural depletion scenario, our simulations show a significant decrease in reservoir pressure and the formation of drawdown cones leading to asphaltene deposition in the bottom-hole area of production wells, decreasing their productivity. Water injection generally allows us to significantly reduce the volume of asphaltene phase transitions and has a positive effect on cumulative oil production. Injecting water into aquifer can keep the formation pressure long above the pressure for asphaltene precipitation, preventing the asphaltene deposition resul

关键词： oilfield development asphaltene deposition uncertainty evaluation sensitivity analysis compositional reservoir simulation

GLOBAL EXPONENTIAL STABILITY OF HOPFIELD NEURAL NETWORKS WITH VARIABLE DELAYS AND IMPULSIVE EFFECTS

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Applied Mathematics and Mechanics(English Edition) 2006年第11期27卷 1517-1522页

作者：杨志春徐道义 Mathematics College Chongqing Normal UniversityChongqing 400047P. R. China Yangtze Center of MathematicsSichuan UniversityChengdu 610064P. R. China Yangtze center of Mathematics Sichuan UniversityChengdu 610064P. R. China

A class of Hopfield neural network with time-varying delays and impulsive effects is concerned. By applying the piecewise continuous vector Lyapunov function some sufficient conditions were obtained to ensure the global exponential stability of impulsive delay neural networks. An example and its simulation are given to illustrate the effectiveness of the results.

关键词： neural networks impulse delay stability

Intelligent Voltage Control Method in Active Distribution Networks Based on Averaged Weighted Double Deep Q-network Algorithm

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Journal of Modern Power Systems and Clean Energy 2023年第1期11卷 132-143页

作者： Yangyang Wang Meiqin Mao Liuchen Chang Nikos D.Hatziargyriou Research center for Photovoltaic System Engineering Ministry of EducationSchool of Electrical Engineering and AutomationHefei University of TechnologyHefei 230009China University of New Brunswick FrederictonNB E3B 5A3Canada National Technical University of Athens Athens 15780Greece IEEE

High penetration of distributed renewable energy sources and electric vehicles(EVs)makes future active distribution network(ADN)highly variable.These characteristics put great challenges to traditional voltage control methods.Voltage control based on the deep Q-network(DQN)algorithm offers a potential solution to this problem because it possesses humanlevel control performance.However,the traditional DQN methods may produce overestimation of action reward values,resulting in degradation of obtained solutions.In this paper,an intelligent voltage control method based on averaged weighted double deep Q-network(AWDDQN)algorithm is proposed to overcome the shortcomings of overestimation of action reward values in DQN algorithm and underestimation of action reward values in double deep Q-network(DDQN)algorithm.Using the proposed method,the voltage control objective is incorporated into the designed action reward values and normalized to form a Markov decision process(MDP)model which is solved by the AWDDQN algorithm.The designed AWDDQN-based intelligent voltage control agent is trained offline and used as online intelligent dynamic voltage regulator for the ADN.The proposed voltage control method is validated using the IEEE 33-bus and 123-bus systems containing renewable energy sources and EVs,and compared with the DQN and DDQN algorithms based methods,and traditional mixed-integer nonlinear program based methods.The simulation results show that the proposed method has better convergence and less voltage volatility than the other ones.

关键词： Averaged weighted double deep Q-network(AWDDQN) deep Q learning active distribution network(ADN) voltage control electrical vehicle(EV)

Characteristics of dust distributions and dust control measures around road-header drivers in mining excavation roadways

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Particuology 2021年第5期19卷 268-275页

作者： Shengyong Hu Yang Gao Guorui Feng Yisheng Huang He Shaoa Qi Liao Fei Hu College of Safety and Emergency Management Engineering Taiyuan University of TechnologyTaiyuan 030024China College of Mining Engineering Taiyuan University of TechnologyTaiyuan 030024China Green Mining Engineering Technology Research center of Shanxi Province Taiyuan 030024China

In the present study,a numerical simulation method was adopted in order to examine the characteristics of dust dispersion during continuous dust release periods(CRP)and stop dust release periods(SRP).The purpose was to analyze the dust distributions and migration actions around road-header drivers in excavation roadways,and then determine effective dust control measures for underground coal mines.This study’s simulation results showed that the dust concentrations continuously increased,and then gradually reached a stability level during the CRP.During that time,the locations of the drivers were always at the intersection of the original migration dust and the backflow dust,and the drivers were invaded by these two strands dust.However,during the SRP,the dust concentrations gradually decreased under the actions of the roadway ventilation.Besides,obvious backflow phenomena were observed around the road-header during the SRP.The locations of the drivers were still within the backflow paths of the high dust concentrations.At the present time,dust separation and extraction systems have been implemented in coal mines,including vacuuming and air knife devices,which are designed to control the dust around the road-header drivers.The field applications of these systems were conducted in the 26 mechanized excavation faces of the Zhangcun Coal Mine.The results revealed that the use of these dust removal systems could effectively reduce the dust concentrations around the road-header drivers.In the present study,the dust removal rates during the CRP and SRP were determined to reach up to 88.7% and 94.6%,respectively.Therefore,the results of this research study provided effective theoretical guidance of the characteristics of dust distributions in coal mines,and introduced effective control methods for the hazardous dust concentrations around road-header drivers during the excavation process.

关键词： Excavation roadway Road-header driver Dust distribution Dust control Numerical simulation

A Unified Lorenz-Like System and Its Tracking Control

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Communications in Theoretical Physics 2015年第3期63卷 317-324页

作者：李春来赵益波 College of Physics and Electronics Hunan Institute of Science and Technology School of Electronic & Information Engineering Nanjing University of Information Science and Technology Jiangsu Collaborative Innovation center on Atmospheric Environment and Equipment Nanjing

This paper introduces the finding of a unified Lorenz-like system.By gradually tuning the only parameter d,the reported system belongs to Lorenz-type system in the sense defined by Clikovsky.Meanwhile,this system belongs to Lorenz-type system,Lu-type system,Chen-type system with d less than,equivalent to and greater than 1.5,respectively,according to the classification defined by Yang.However,this system can only generate a succession of Lorenz-like attractors.Some basic dynamical properties of the system are investigated theoretically and numerically.Moreover,the tracking control of the system with exponential convergence rate is studied.Theoretical analysis and computer simulation show that the proposed scheme can allow us to drive the output variable x\ to arbitrary reference signals exponentially,and the guaranteed exponential convergence rate can be estimated accurately.

关键词：报告系统跟踪控制洛伦兹指数收敛速度动力学特性计算机模拟数值研究输出变量

Simulated impacts of 3D urban morphology on urban transportation in megacities: case study in Beijing

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International Journal of Digital Earth 2014年第6期7卷 470-491页

作者： Shuo Liu Xiangtao Fan Qingke Wen Wei Liang Yuanfeng Wu Key Laboratory of Digital Earth Center for Earth Observation and Digital EarthChinese Academy of SciencesBeijingChina The Institute of Remote Sensing Applications Chinese Academy of SciencesBeijingChina

Urban morphology and morphology change and their impacts on urban transportation have been studied extensively in planar urban space.The essential feature of urban space,however,is its three-dimensionality(3D),and few studies have been conducted from a 3D perspective,overly limiting the accuracy of studies on the relationships between urban morphology and transportation.The aim of this paper is to simulate the impacts of 3D urban morphologies on urban transportation under the Digital Earth framework.On the basis of the principle that population distribution and movement are largely confined by 3D urban morphologies,which affect transportation,high spatial resolution remote sensing imagery and a thematic vector data-set were used to extract urban morphology and transportation-related variables.With a combination of three research methods-factor analysis,spatial regression analysis and Euclidean allocation-we provide an effective method to construct a simulation model.The paper indicates three general results.First,building capacity in the urban space has the most significant impact on traffic condition.Second,obvious urban space otherness,reflecting both use density characteristics and functional character-istics of urban space,mostly results in heavier traffic flow pressure.Third,no single morphology density indicator or single urban structure indicator can reflect its contribution to the pressure of traffic flow directly,but a combination of these different indicators has the ability to do so.

关键词： digital city 3D urban morphologies simulation of urban transportation spatial regression euclidean allocation feature factor of 3D urban morphology

Hierarchical structures hydrogel evaporator and superhydrophilic water collect device for efficient solar steam evaporation

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Nano Research 2021年第4期14卷 1135-1140页

作者： Wenwei Lei Sovann Khan Lie Chen Norihiro Suzuki Chiaki Terashima Kesong Liu Akira Fujishima Mingjie Liu Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China Photocatalysis International Research center Tokyo University of Science2641 YamazakiNodaChiba 278-8510Japan

Efficient light absorption and trapping are of vital importance for the solar water evaporation by hydrogel-based photothermal conversion materials.Conventional strategies are focused on the development of the composition and structure of the hydrogers internal network.In our point of view,the importance of the surface structure of hydrogel has usually been underestimated or ignored.Here inspired by the excellent absorbance and water transportation ability of biological surface structure,the hierarchical structured hydrogel evaporators(HSEs)increased the light absorption,trapping,water transportation and water-air interface,which is the beneficial photothermal conversion and water evaporation.The HSEs showed a rapid evaporation rate of 1.77 kg·m^(-2)·h^(-1)at about 92%energy efficiency under one sun(1 kW·m^(-2)).Furthermore,the superhydrophilic window device was used in this work to collect the condensed water,which avoids the light-blocking caused by the water mist formed by the small droplets and the problem of the droplets stick on the device dropping back to the bulk water.Integrated with the excellent photothermal conversion hydrogel and superhydrophilic window equipment,this work provides efficient evaporation and desalination of hydrogel-based solar evaporators in practical large-scale applications.

关键词： light-trapping large-scale hierarchical structure hydrogel evaporator solar steam evaporation superhydrophilic window

Sensing of cytoplasmic chromatin by cGAS activates innate immune response in SARS-CoV-2 infection

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Signal Transduction and Targeted Therapy 2021年第12期6卷 3653-3665页

作者： Zhuo Zhou Xinyi Zhang Xiaobo Lei Xia Xiao Tao Jiao Ruiyi Ma Xiaojing Dong Qi Jiang Wenjing Wang Yujin Shi Tian Zheng Jian Rao Zichun Xiang Lili Ren Tao Deng Zhengfan Jiang Zhixun Dou Wensheng Wei Jianwei Wang Biomedical Pioneering Innovation center Beijing Advanced Innovation Center for GenomicsPeking-Tsinghua Center for Life SciencesPeking University Genome Editing Research CenterState Key Laboratory of Protein and Plant Gene ResearchSchool of Life SciencesPeking UniversityBeijingChina NHC Key Laboratory of Systems Biology of Pathogens Institute of Pathogen BiologyChinese Academy of Medical Sciences and Peking Union Medical College100730 BeijingP.R.China Key Laboratory of Respiratory Disease Pathogenomics Chinese Academy of Medical Sciences and Peking Union Medical College100730 BeijingP.R.China Christophe Merieux Laboratory Institute of Pathogen BiologyChinese Academy of Medical Sciences and Peking Union Medical College100730 BeijingP.R.China CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education School of Life SciencesPseking UniversityBeijing 100871China Peking-Tsinghua center for Life Sciences Peking UniversityBeijing 100871China center for Regenerative Medicine Massachusetts General HospitalBostonMAUSA Harvard Stem Cell Institute Harvard UniversityCambridgeMAUSA Department of Medicine Massachusetts General HospitalHarvard Medical SchoolBostonMAUSA

The global coronavirus disease 2019(COVID-19)pandemic is caused by severe acute respiratory syndrome coronavirus 2(SARSCoV-2),a positive-sense RNA virus.How the host immune system senses and responds to SARS-CoV-2 infection remain largely unresolved.Here,we report that SARS-CoV-2 infection activates the innate immune response through the cytosolic DNA sensing cGAS-STING pathway.SARS-CoV-2 infection induces the cellular level of 2′3′-cGAMP associated with STING activation.cGAS recognizes chromatin DNA shuttled from the nucleus as a result of cell-to-cell fusion upon SARS-CoV-2 infection.We further demonstrate that the expression of spike protein from SARS-CoV-2 and ACE2 from host cells is sufficient to trigger cytoplasmic chromatin upon cell fusion.Furthermore,cytoplasmic chromatin-cGAS-STING pathway,but not MAVS-mediated viral RNA sensing pathway,contributes to interferon and pro-inflammatory gene expression upon cell fusion.Finally,we show that cGAS is required for host antiviral responses against SARS-CoV-2,and a STING-activating compound potently inhibits viral replication.Together,our study reported a previously unappreciated mechanism by which the host innate immune system responds to SARS-CoV-2 infection,mediated by cytoplasmic chromatin from the infected cells.Targeting the cytoplasmic chromatin-cGAS-STING pathway may offer novel therapeutic opportunities in treating COVID-19.In addition,these findings extend our knowledge in host defense against viral infection by showing that host cells’self-nucleic acids can be employed as a“danger signal”to alarm the immune system.

关键词： infection Together cGAS