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Dynamic changes of behaviors,dentate gyrus neurogenesis and hippocampal miR-124 expression in rats with depression induced by chronic unpredictable mild stress 预览
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作者 Yun-Ling Huang Ning-Xi Zeng +5 位作者 Jie Chen Jie Niu Wu-Long Luo Ping Liu Can Yan Li-Li Wu 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第6期1150-1159,共10页
The depression-like behavior phenotype,neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy.The pre... The depression-like behavior phenotype,neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy.The present study aimed to clarify the dynamic changes of depression-like behavior,dentate gyrus neurogenesis and hippocampal miR-124 expression during depression induced by chronic stress to reveal pathological features at different stages of depression and to further provide insight into depression treatment.Chronic unpredictable mild stress depression models were established by exposing Sprague-Dawley rats to various mild stressors,including white noise,thermal swimming,stroboscopic illumination,soiled cages,pairing with three other stressed animals,cold swimming,tail pinch,restraint and water and food deprivation.Chronic unpredictable mild stress model rats underwent dynamic observation from 1 to 8 weeks and were compared with a control group(normal feeding without any stressors).To observe changes in the depression-like behavior phenotype during chronic unpredictable mild stress-induced depression,a sucrose preference test was used to evaluate the degree of anhedonia.An open-field test was used to evaluate locomotor activity and anxiety status.Compared with the control group,chronic unpredictable mild stress rats lost weight but did not have a depression-like behavioral phenotype at 1-4 weeks.Chronic unpredictable mild stress rats presented decreased sucrose preference and locomotor activity at 5-8 weeks.In addition,chronic unpredictable mild stress rats did not have significant anxiety-like behavior during 1-8 weeks of modeling.To observe neurogenesis dysfunctions and changes in neuronal number in the dentate gyrus during chronic unpredictable mild stress-induced depression,markers(DCX and DCX/BrdU)of neural proliferation and differentiation and the neuronal marker NeuN were assessed by immunofluorescence.Compared with the control group,neurogenesis and the neuronal number in the dentate gyrus did not 展开更多
关键词 chronic unpredictable mild stress model continuous observation DEPRESSION depression-like behavior dynamic changes HIPPOCAMPUS miR-124 neurogenesis dysfunction neuronal loss
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Fuzzy Behavior-based Control of Three Wheeled Omnidirectional Mobile Robot
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作者 Nacer Hacene Boubekeur Mendil 《国际自动化与计算杂志:英文版》 EI CSCD 2019年第2期163-185,共23页
In this paper, a fuzzy behavior-based approach for a three wheeled omnidirectional mobile robot (TWOMR) navigation has been proposed. The robot has to track either static or dynamic target while avoiding either static... In this paper, a fuzzy behavior-based approach for a three wheeled omnidirectional mobile robot (TWOMR) navigation has been proposed. The robot has to track either static or dynamic target while avoiding either static or dynamic obstacles along its path. A simple controller design is adopted, and to do so, two fuzzy behaviors "Track the Target" and "Avoid Obstacles and Wall Following" are considered based on reduced rule bases (six and five rules respectively). This strategy employs a system of five ultrasonic sensors which provide the necessary information about obstacles in the environment. Simulation platform was designed to demonstrate the effectiveness of the proposed approach. 展开更多
关键词 THREE WHEELED OMNIDIRECTIONAL mobile robot (TWOMR) autonomous navigation OBSTACLE avoidance FUZZY behaviorbased control DYNAMIC target DYNAMIC environment
A Dynamic Access Control Method for SDN 预览
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作者 Dexian Chang Wanzhong Sun +1 位作者 Yingjie Yang Tingting Wang 《电脑和通信(英文)》 2019年第10期105-115,共11页
Aiming at the problem that network topology changes frequently in SDN (Software Defined Network) environment and it is difficult to implement fine-grained access control, utilizing the characteristics of SDN transfer ... Aiming at the problem that network topology changes frequently in SDN (Software Defined Network) environment and it is difficult to implement fine-grained access control, utilizing the characteristics of SDN transfer control separation and software programming, the ABAC model (Attribute-Based Access Control) is extended by introducing security level, and the security level is defined for the attributes of subject and object to establish the access mapping relationship based on mandatory access rules. At the same time, with secure access path as SDN access control attribute, a dynamic generation method of access control path based on PSO (Particle Swarm Optimization) algorithm is designed to ensure the security of access data flow. The prototype system experiments show that the proposed method takes into account the fine-grained and dynamic requirements of SDN access control, and improves the access security of SDN while ensuring the access efficiency. 展开更多
关键词 ACCESS CONTROL SECURITY SDN ABAC DYNAMIC
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Impact of recycling improvement on the life cycle of phosphorus
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作者 Mohammad El Wali Saeed Rahimpour Golroudbary Andrzej Kraslawski 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第5期1219-1229,共11页
Access to natural resources is increasingly more difficult and more costly, partly due to their economic significance and to continuous increase of their global consumption in the recent years. In the case of phosphor... Access to natural resources is increasingly more difficult and more costly, partly due to their economic significance and to continuous increase of their global consumption in the recent years. In the case of phosphorus (P), which is a critical raw material, geological distribution of its primary nonrenewable source (phosphate rock) is concentrated in particular regions leading to high supply risk of this raw material. In Europe (EU-28), where phosphate rock reserves are scarce, import of phosphorus has been the main source of supply. It means that Europe relies highly on the foreign exporters. From decision makers' perspective, recycling of phosphorus was taken into account as one of the possible solutions to decrease the dependence on imports and extraction of reserves. The question, however, is to what extent does the recycling of phosphorus help in reducing the reliance on typical supply resources? Hence, the main objective of this paper is to quantify the dynamic flow of phosphorus and show potential benefits of its recycling in Europe. This article presents a system dynamics model for representation of the element P flow and helps to quantify to what extent the recycled phosphorus could mitigate its criticality. Analysis of the results supports previous studies indicating the high reliance ofEU on P imports, estimating around 96% as the reliance percentage on imports. The results imply that improving P recycling has the potential to decrease the level of P imports to a certain extent, which may reach 79%. 展开更多
关键词 CRITICAL material PHOSPHORUS DYNAMIC MODELLING DYNAMIC simulation RECOVERY RECYCLING
Comprehensive analysis of the influence of structural and dynamic parameters on the accuracy of nano-precision positioning stages
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作者 Chengyuan LIANG Fang YUAN +3 位作者 Xuedong CHEN Wei JIANG Lizhan ZENG Xin LUO 《机械工程前沿:英文版》 CSCD 2019年第3期255-272,共18页
Nano-precision positioning stages are characterized by rigid-flexible coupling systems. The complex dynamic characteristics of mechanical structure of a stage, which are determined by structural and dynamic parameters... Nano-precision positioning stages are characterized by rigid-flexible coupling systems. The complex dynamic characteristics of mechanical structure of a stage, which are determined by structural and dynamic parameters, exert a serious influence on the accuracy of its motion and measurement. Systematic evaluation of such influence is essential for the design and improvement of stages. A systematic approach to modeling the dynamic accuracy of a nano-precision positioning stage is developed in this work by integrating a multi-rigid-body dynamic model of the mechanical system and measurement system models. The influence of structural and dynamic parameters, including aerostatic bearing configurations, motion plane errors, foundation vibrations, and positions of the acting points of driving forces, on dynamic accuracy is investigated by adopting the H-type configured stage as an example. The approach is programmed and integrated into a software framework that supports the dynamic design of nano-precision positioning stages. The software framework is then applied to the design of a nano-precision positioning stage used in a packaging lithography machine. 展开更多
关键词 nano-precision POSITIONING stage analysis and design structural and DYNAMIC parameters DYNAMIC ACCURACY systematic modeling
The effect of monosaccharides on self-assembly of benzenetricarboxamides
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作者 Jue Wang Wenjing Qi Guosong Chen 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第3期587-591,共5页
The interaction between monosaccharides exhibits an important role in the assembly of monosaccharide-containing molecules. In this work, three common monosaccharides, glucose, galactose and mannose, are employed to in... The interaction between monosaccharides exhibits an important role in the assembly of monosaccharide-containing molecules. In this work, three common monosaccharides, glucose, galactose and mannose, are employed to investigate the effect of monosaccharide on the self-assembly of benzenetricarboxamide(BTA) core-containing molecules. In the presence of monosaccharides, three benzenetricarboxamide derivatives aggregate into different ordered structures. When alanine linkers are introduced to these molecules between the core and the monosacchride, morphologies of three types of monosaccharide BTAs turned to disordered, meanwhile their structures become similar with the increase of the length of alanine linkers, indicating the disappearance of the monosaccharide effects. 展开更多
关键词 MONOSACCHARIDE SELF-ASSEMBLY Benzenetricarboxamide DYNAMIC LIGHT scatting (DLS) Depolarized DYNAMIC LIGHT scatting (DDLS)
Dynamic experimental studies of a6n01s-t5 aluminum alloy material and structure for high-speed train 预览
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作者 Zishang Liu YangyangYu +4 位作者 Zhe Yang Yanpeng Wei Junshuang Cai Maohui Li Chenguang Huang 《力学学报:英文版》 SCIE EI CAS CSCD 2019年第4期763-772,共10页
In this study, we focus on the dynamic failure property of A6N01S-T5 aluminum alloyusing for high-speed train. The method of SHBT+3D DIC was put forward to figure out the dynamic mechanical properties and dynamic fail... In this study, we focus on the dynamic failure property of A6N01S-T5 aluminum alloyusing for high-speed train. The method of SHBT+3D DIC was put forward to figure out the dynamic mechanical properties and dynamic failure strain of A6N01S-T5 aluminum alloy,and on the basis of this, Johnson-Cook model constitutive parameters and dynamic failure strain parameters were obtained through a series of static and dynamic tests.An important character of this methodwas that the sandwich structure from the true high-speed train was used in penetration test,followed by the numerical calculation of the same working condition using LS-DYNA.Then we compare the experimental results with simulation results mentioned above in terms of failure morphology in structure and the bullet speed throughout the entire process to verifythe accuracyof the parameter. The experimental results provide a data basis for the crash simulation model of high-speed trains,in turn to optimize the structural design and whole efficiency. 展开更多
关键词 A6N01S-T5 ALUMINUM alloy DYNAMIC FAILURE STRAIN CONSTITUTIVE model DYNAMIC mechanical properties
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Experimental Study on Dynamic Mechanical Properties of Sprayed Concrete-Surrounding Rock Combined Body 预览
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作者 Dongming Guo Pengyang Yan +2 位作者 Longfei Fan Yingshi Zhang Xiaoye Wang 《北京理工大学学报:英文版》 EI CAS 2019年第2期278-285,共8页
To investigate the dynamic response problem of the double medium formed by the adherence of sprayed concrete and surrounding rock in the tunnel,a split Hopkinson pressure bar of 75 mm in diameter was adopted at the ag... To investigate the dynamic response problem of the double medium formed by the adherence of sprayed concrete and surrounding rock in the tunnel,a split Hopkinson pressure bar of 75 mm in diameter was adopted at the ages of 3,7 and 10 d.Experimental results showed that dynamic compressive strength and dynamic increase factors(DIF)of the combined bodies increase with the strain rate.With the growth of strain rate,the critical strain of the combined bodies first increases,then deceases.Furthermore,the combined bodies of 3 d reveal the plastic property and brittle property for 7 d and 10 d when the strain rate is over 80/s.The failure characteristic of the sprayed concrete changes from tearing strain damage to crushing damage as the growth of strain rate,and the failure characteristic of rock presents the tensile failure mode as demonstrated by the scanning electron microscope(SEM). 展开更多
关键词 SPRAYED concrete-surrounding rock COMBINED BODY DYNAMIC compressive strength DYNAMIC increase factors critical strain failure modes
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Dynamic crushingof cellular materials: a particle velocity-based analytical method and its application 预览
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作者 Shilong Wang Zhijun Zheng +2 位作者 Yuanyuan Ding Changfeng Zhu Jilin Yu 《力学学报:英文版》 SCIE EI CAS CSCD 2019年第4期839-851,共13页
Cellular material under high-velocity impacthas a typical feature oflayer-wise collapse.A cell-based finite element model is employed to simulate the direct impact of closed-cell foam, and one-dimensional velocity fie... Cellular material under high-velocity impacthas a typical feature oflayer-wise collapse.A cell-based finite element model is employed to simulate the direct impact of closed-cell foam, and one-dimensional velocity field distributionsareobtained to characterize thecrushing bandpropagating through a cellular material. An explicit expression of continuous velocity distribution is derivedbased on the features of velocity gradient distribution. The velocity distribution function is adopted to determine the dynamic stress-strain statesof cellular materials under dynamic loading.The local stress-strain history distribution reveals that sectional cells experience a process from the precursor of elastic behavior to the shock stress state, through the dynamic initial crushing state. A power-law relation between the dynamic initial crushing stress andthe strainrate isestablished, which confirms the strain-rate effect of cellular materials. By extracting the critical points immediately before the unloading stage on the local dynamic stress-strain history curves, the dynamic stress-strain statesof cellular materials are determined. They exhibit loading rate-dependence but are independent of the initial impact velocity.Furthermore, with the increase of relative density, the dynamic hardening behaviorof cellular specimen is enhanced and the crushing process event is advanced. The particle velocity-based analytical method is appliedto analyze the dynamic responses of cellular materials.This method is better than continuum-based shock models, since itdoes not require a pre-assumed constitutive relation.Therefore,the particle velocity-based analytical method proposed in this study may provide new ideas to carry out dynamic experimental measurement, which is especially applicable toinhomogeneous materials. 展开更多
关键词 CELLULAR material VELOCITY distribution DYNAMIC behavior STRAIN-RATE effect DYNAMIC STRESS-STRAIN STATE
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One-dimensional dynamic compressive behavior of dry calcareous sand at high strain rates 预览
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作者 Yaru Lv Jiagui Liu Ziming Xiong 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期192-201,共10页
Calcareous sand has distinct characteristics in comparison with silica sand,such as dynamic behavior at high strain rates(HSRs).This is closely related to pile driving,aircraft wheel loading and mining activities.To u... Calcareous sand has distinct characteristics in comparison with silica sand,such as dynamic behavior at high strain rates(HSRs).This is closely related to pile driving,aircraft wheel loading and mining activities.To understand the response of calcareous sand at HSRs,a series of dynamic tests is performed using the split Hopkinson pressure bar(SHPB)with steel sleeve,including 6 validation tests of bar-against-bar and 16 comparative tests relevant to the relative density and strain rate of calcareous and silica sands.The apparent dynamic stiffness of calcareous sand is approximately 10%of that for silica sand due to different particle shapes and mineral compositions.The axial stress-strain response of silica sand is mainly governed by the deformation of individual grain and soil skeleton,and particle crushing.However,porous calcareous sand shows yielding and strain-hardening responses that are always followed by particle crushing.As the applied loading increases,the particle crushing of calcareous sand develops from local instability to whole breakage.Calcareous sand has lower viscous flow effects compared with silica sand at HSRs. 展开更多
关键词 Split Hopkinson pressure bar(SHPB)test CALCAREOUS sand DYNAMIC behavior DYNAMIC STIFFNESS Particle CRUSHING
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Study on Rigid-Flexible Coupling Effects of Floating Offshore Wind Turbines 预览
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作者 CHEN Jia-hao HU Zhi-qiang +1 位作者 LIU Ge-liang WAN De-cheng 《中国海洋工程:英文版》 SCIE EI CSCD 2019年第1期1-13,共13页
In order to account for rigid-flexible coupling effects of floating offshore wind turbines,a nonlinear rigid-flexible coupled dynamic model is proposed in this paper.The proposed nonlinear coupled model takes the high... In order to account for rigid-flexible coupling effects of floating offshore wind turbines,a nonlinear rigid-flexible coupled dynamic model is proposed in this paper.The proposed nonlinear coupled model takes the higher-order axial displacements into account,which are usually neglected in the conventional linear dynamic model.Subsequently,investigations on the dynamic differences between the proposed nonlinear dynamic model and the linear one are conducted.The results demonstrate that the stiffness of the turbine blades in the proposed nonlinear dynamic model increases with larger overall motions but that in the linear dynamic model declines with larger overall motions.Deformation of the blades in the nonlinear dynamic model is more reasonable than that in the linear model as well.Additionally,more distinct coupling effects are observed in the proposed nonlinear model than those in the linear model.Finally,it shows that the aerodynamic loads,the structural loads and global dynamic responses of floating offshore wind turbines using the nonlinear dynamic model are slightly smaller than those using the linear dynamic model.In summary,compared with the conventional linear dynamic model,the proposed nonlinear coupling dynamic model is a higher-order dynamic model in consideration of the rigid-flexible coupling effects of floating offshore wind turbines,and accord more perfectly with the engineering facts. 展开更多
关键词 FLOATING OFFSHORE WIND TURBINE DYNAMIC STIFFENING effect nonlinear coupled DYNAMIC model DARwind
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Locomotion Stability Analysis of Lower Extremity Augmentation Device
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作者 Likun Wang Chaofeng Chen +3 位作者 Wei Dong Zhijiang Du Yi Shen Guangyu Zhao 《仿生工程学报:英文版》 SCIE EI CSCD 2019年第1期99-114,共16页
Stability is of great significance in the theoretical framework of biped locomotion.Real-time control and walking patterns planning are on the premise that the robot works in the stable condition.In this paper,we addr... Stability is of great significance in the theoretical framework of biped locomotion.Real-time control and walking patterns planning are on the premise that the robot works in the stable condition.In this paper,we address the crucial issue of the locomotion stability based on the modified Poincare return map and the hybrid automata.Not akin to the traditional stability criteria,i.e.,the Zero Moment Point(ZMP)and the Center of Mass(CoM),the modified Poincare return map is more appropriate for both dynamic walking arid non-periodic walking.Moreover,a novel high-level reinforcement learning methodology,so-called active PI2 CMA-ES,is proposed in this paper to plan the exoskeleton locomotion.The proposed learning methodology demonstrates that the locomotion of the exoskeleton is asymptotically stable according to the modified Poincare return map criterion.Finally,the proposed learning methodology is tested by the Lower Extremity Augmentation Device(LEAD)and its effectiveness is verified by the experiments. 展开更多
关键词 BIPED locomotion DYNAMIC WALKING DYNAMIC Movement Primitives (DMP) stability EXOSKELETON bioinspiration
Parameter estimation survey for multi-joint robot dynamic calibration case study
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作者 Shaolin ZHANG Shuo WANG +1 位作者 Fengshui JING Min TAN 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第10期102-116,共15页
Accurate model parameters are the basis of robot dynamics. Many linear and nonlinear models have been proposed to calibrate the inertial parameters and friction parameters of multi-joint robots.However, methods of cho... Accurate model parameters are the basis of robot dynamics. Many linear and nonlinear models have been proposed to calibrate the inertial parameters and friction parameters of multi-joint robots.However, methods of choosing a model and calculating its parameters still have few summaries. This paper reviews typical linear/nonlinear models and different calculation methods for robot dynamic calibration.Through simulations, the features of different methods are analyzed, including torque error, parameter error, model adaptability, solution time, and anti-interference ability of the calibration results. Finally, an experiment performed on a six-degree-of-freedom industrial manipulator is used as an example to illustrate how to select the model for a specified robot. These comparisons and experiments provide references for the parameter calibration of multi-joint robots. 展开更多
关键词 DYNAMIC PARAMETER CALIBRATION FRICTION CALIBRATION ROBOT dynamics industrial MANIPULATOR DYNAMIC models
Low frequency vibration control of railway vehicles based on ahigh static low dynamic stiffness dynamic vibration absorber
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作者 SUN Yu GONG Dao +2 位作者 ZHOU JinSong SUN WenJing XIA ZhangHui 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第1期60-69,共10页
In order to control the low frequency vibration of railway vehicles, a vertical two degrees of freedom(2DOF) low frequency dynamic vibration absorber(DVA) based on acceleration is proposed. Parameters of the dynamic v... In order to control the low frequency vibration of railway vehicles, a vertical two degrees of freedom(2DOF) low frequency dynamic vibration absorber(DVA) based on acceleration is proposed. Parameters of the dynamic vibration absorber are put forth to control the low frequency vibration of car body bouncing and pitching. Next, the acceleration power spectrum density(PSD)and ride quality of the car body are calculated based on the pseudo excitation method(PEM) and covariance algorithm,respectively. According to the requirement of 2DOF low frequency DVA, the isolators with high static low dynamic stiffness(HSLDS) are designed. A high-speed train dynamic model containing HSLDS isolators is established to validate the effects on the car body vibration. The results reveal that the 2D low frequency DVA can significantly reduce the vibration of the car body bouncing and pitching. Thus, the ride quality of the vehicle is increased, and passenger comfort is improved. 展开更多
关键词 railway vehicle dynamics RIDE quality LOW frequency DYNAMIC vibration ABSORBER high STATIC LOW DYNAMIC STIFFNESS
Dynamic Fracture Analysis for Shale Material by Peridynamic Modelling 预览
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作者 Zhanqi Cheng Zhenyu Wang Zhongtao Luo 《工程与科学中的计算机建模(英文)》 2019年第3期509-527,共19页
In this work,a bond-based peridynamics(PD)model was built to analyze the dynamic fracture of shale material.Both the the convergence studies and the result of dynamic crack propagation were presented.As well-known,cra... In this work,a bond-based peridynamics(PD)model was built to analyze the dynamic fracture of shale material.Both the the convergence studies and the result of dynamic crack propagation were presented.As well-known,crack propagation,aggregation,and bifurcation play an critical role in the failure analysis of brittle materials such as shale.The dynamic crack propagation and branching analysis of shale by using the PD method were discussed.Firstly,the valid and accuracy of the PD model for the rock materials was verified by comparing with the existed numerical results.Secondly,we discussed the convergence both with uniform grid refinement(m-convergence)and decreasing the peridynamics horizon(δ-convergence).Then the shale material with two pre-crack under uniaxial compression using the present PD model were discussed,and the influence of the different angle of flaws on the behavior of crack propagation was also analyzed.The results shows that both the loading conditions and the angle of flaws can influences the crack propagation in shale. 展开更多
关键词 PERIDYNAMICS SHALE dynamic fracture crack propagation dynamic loads
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Dynamic Performance Analysis of Steel Frame Structure under Seismic Action 预览
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作者 Xiaojun Yuan Jinlong Liu +2 位作者 Yanmu Qu Kailin Wei Haifeng Zong 《建筑与工程前沿研究(英文)》 2019年第2期1-4,共4页
In order to find out the dynamic characteristics of a steel frame structure project in the 8 degree (0.3g) area, the artificial wave, Taft wave and El Centro wave were input by using the finite element analysis softwa... In order to find out the dynamic characteristics of a steel frame structure project in the 8 degree (0.3g) area, the artificial wave, Taft wave and El Centro wave were input by using the finite element analysis software ANSYS. The dynamic time-history analysis of the structure shows the dynamic performance of the structure under the frequent earthquakes and rare earthquakes. 展开更多
关键词 STEEL FRAME STRUCTURE DYNAMIC TIME-HISTORY ANALYSIS DYNAMIC performance
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Genetic programming for predictions of effectiveness of rolling dynamic compaction with dynamic cone penetrometer test results 预览
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作者 R.A.T.M.Ranasinghe M.B.Jaksa +1 位作者 F.Pooya Nejad Y.L.Kuo 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第4期815-823,共9页
Rolling dynamic compaction (RDC),which employs non-circular module towed behind a tractor,is an innovative soil compaction method that has proven to be successful in many ground improvement applications.RDC involves r... Rolling dynamic compaction (RDC),which employs non-circular module towed behind a tractor,is an innovative soil compaction method that has proven to be successful in many ground improvement applications.RDC involves repeatedly delivering high-energy impact blows onto the ground surface,which improves soil density and thus soil strength and stiffness.However,there exists a lack of methods to predict the effectiveness of RDC in different ground conditions,which has become a major obstacle to its adoption.For this,in this context,a prediction model is developed based on linear genetic programming (LGP),which is one of the common approaches in application of artificial intelligence for nonlinear forecasting.The model is based on in situ density-related data in terms of dynamic cone penetrometer (DCP) results obtained from several projects that have employed the 4-sided,8-t impact roller (BH-1300).It is shown that the model is accurate and reliable over a range of soil types.Furthermore,a series of parametric studies confirms its robustness in generalizing data.In addition,the results of the comparative study indicate that the optimal LGP model has a better predictive performance than the existing artificial neural network (ANN) model developed earlier by the authors. 展开更多
关键词 Ground improvement ROLLING DYNAMIC compaction (RDC) Linear genetic programming (LGP) DYNAMIC cone PENETROMETER (DCP) test
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Online adaptive Q-learning method for fully cooperative linear quadratic dynamic games
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作者 Xinxing LI Zhihong PENG +2 位作者 Lei JIAO Lele XI Junqi CAI 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第12期148-161,共14页
A model-based offline policy iteration(PI) algorithm and a model-free online Q-learning algorithm are proposed for solving fully cooperative linear quadratic dynamic games. The PI-based adaptive Q-learning method can ... A model-based offline policy iteration(PI) algorithm and a model-free online Q-learning algorithm are proposed for solving fully cooperative linear quadratic dynamic games. The PI-based adaptive Q-learning method can learn the feedback Nash equilibrium online using the state samples generated by behavior policies, without sending inquiries to the system model. Unlike the existing Q-learning methods, this novel Q-learning algorithm executes both policy evaluation and policy improvement in an adaptive manner.We prove the convergence of the offline PI algorithm by proving its equivalence to Newton’s method while solving the game algebraic Riccati equation(GARE). Furthermore, we prove that the proposed Q-learning method will converge to the Nash equilibrium under a small learning rate if the method satisfies certain persistence of excitation conditions, which can be easily met by suitable behavior policies. Our simulation results demonstrate the good performance of the proposed online adaptive Q-learning algorithm. 展开更多
关键词 adaptive dynamic programming reinforcement learning Q-LEARNING fully cooperative linear quadratic dynamic games policy iteration off-policy
Yang’s Dynamic Vertical Balance Process for the Content of Cd in a Marine Bay 预览
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作者 Dongfang Yang Sivakumar Manickam +2 位作者 Danfeng Yang Sixi Zhu Ming Wang 《地球科学和环境保护期刊(英文)》 2019年第5期16-25,共10页
This study analyzes the horizontal and vertical migration processes of Cd contents based on the investigations conducted during May and August 1990. It reveals the dynamic balance process of Cd substance in a marine b... This study analyzes the horizontal and vertical migration processes of Cd contents based on the investigations conducted during May and August 1990. It reveals the dynamic balance process of Cd substance in a marine bay and shows that in the waters close to the source input, the content of Cd in the surface waters is the highest, and also the vertical dilution amount is the highest. This is the beginning of the dynamic vertical balance process. Along with distance from the source input, the sedimentation is an ongoing process, which results in a decrease in the content of Cd in the surface waters, and a reduction in the vertical dilution amount. This process continues to the balance point. In waters far away from the source input, the content of Cd is homogeneous in the waters, and the vertical dilution amount decreases to the lowest value, i.e., the balance point. Furthermore, a block diagram has been provided to demonstrate the dynamic vertical balance process. 展开更多
关键词 CADMIUM BALANCE DYNAMIC Process Jiaozhou BAY
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Evaluation and scenario simulation for forest ecological security in China 预览
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作者 Qin Zhang Guangyu Wang +4 位作者 Feng Mi Xuanchang Zhang Lianzhen Xu Yufang Zhang Xiaoli Jiang 《林业研究:英文版》 CAS CSCD 2019年第5期1651-1666,共16页
Continuously growing populations and rapid economic development have led to the excessive use of forest resources,and the forest ecosystem is threatened.In response,forest ecological security(FES)has attracted attenti... Continuously growing populations and rapid economic development have led to the excessive use of forest resources,and the forest ecosystem is threatened.In response,forest ecological security(FES)has attracted attention.In this study,an integrated dynamic simulation model was constructed using the system dynamic method,and it was used to evaluate the FES in China from 1999 to 2014.A scenario analysis was then used to evaluate the changes in the FES under five forestry policy scenarios for the 2015–2050 period,including the baseline,afforestation policy,harvesting policies,management policy,investment policy,and a policy mix.The results showed that the evaluation values of the FES increased during the period from 1999 to 2002,the period from 2004 to 2010 and the year 2014,and they decreased in 2003 and during the period from 2011 to 2013.During the 2015–2050 simulation period,the FES improved continuously.In particular,China would enter a new stage when the economic systems,social systems and ecosystems were in harmony after 2040.To improve the FES and the current status of the FES,a scenario analysis showed the most suitable scenario to be Scenario 5 from 2015 to 2020 and Scenario 2 from 2021 to 2050.To relieve pressure,the most suitable scenario would be Scenario 5 from 2015 to 2040 and from 2046 to 2050,and the most suitable scenario would be Scenario 4 for 2041–2045.A policy mix(Scenario 5)would be most efficient under current conditions,while the effects of all the benefits of the forestry policies would weaken over the long term.The integrated method can be regarded as a decision support tool to help policy makers understand FES and promulgate a reasonable forestry policy. 展开更多
关键词 DYNAMIC change TREND FOREST ECOLOGICAL security Integrated EVALUATION method System DYNAMIC model POLICY simulation
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