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Asymptotic solution of a wide moving jam to a class of higher-order viscous traffic flow models 被引量:1
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作者 Chunxiu WU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第5期609-622,共14页
The boundary-layer method is used to study a wide moving jam to a class of higher-order viscous models. The equations for characteristic parameters are derived to determine the asymptotic solution. The sufficient and ... The boundary-layer method is used to study a wide moving jam to a class of higher-order viscous models. The equations for characteristic parameters are derived to determine the asymptotic solution. The sufficient and essential conditions for the wide moving jam formation are discussed in detail, respectively, and then used to prove or disprove the existence of the wide moving jam solutions to many well-known higher-order models. It is shown that the numerical results agree with the analytical results. 展开更多
关键词 higher-order traffic flow model wide moving jam boundary-layer method weighted essentially nonoscillatory (WENO) scheme
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Solitary wave solutions to higher-order traffic flow model with large diffusion
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作者 菅肖霞 张鹏 +2 位作者 S.C.WONG 乔殿梁 崔岐柱 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第2期167-176,共10页
This paper uses the Taylor expansion to seek an approximate Korteweg- de Vries equation (KdV) solution to a higher-order traffic flow model with sufficiently large diffusion. It demonstrates the validity of the appr... This paper uses the Taylor expansion to seek an approximate Korteweg- de Vries equation (KdV) solution to a higher-order traffic flow model with sufficiently large diffusion. It demonstrates the validity of the approximate KdV solution considering all the related parameters to ensure the physical boundedness and the stability of the solution. Moreover, when the viscosity coefficient depends on the density and velocity of the flow, the wave speed of the KdV solution is naturally related to either the first or the second characteristic field. The finite element method is extended to solve the model and examine the stability and accuracy of the approximate KdV solution. 展开更多
关键词 higher-order traffic flow model viscosity coefficient approximate Korteweg-de Vries equation (KdV) solution finite element scheme
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Analytical Higher-Order Model for Flexible and Stretchable Sensors
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作者 ZHANG Yongfang ZHU Hongbin +3 位作者 LIU Cheng LIU Xu LIU Fuxi L Yanjun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第2期379-386,共8页
The stretchable sensor wrapped around a foldable airfoil or embedded inside of it has great potential for use in the monitoring of the structural status of the foldable airfoil.The design methodology is important to t... The stretchable sensor wrapped around a foldable airfoil or embedded inside of it has great potential for use in the monitoring of the structural status of the foldable airfoil.The design methodology is important to the development of the stretchable sensor for status monitoring on the foldable airfoil.According to the requirement of mechanical flexibility of the sensor,the combined use of a layered flexible structural formation and a strain isolation layer is implemented.An analytical higher-order model is proposed to predict the stresses of the strain-isolation layer based on the shear-lag model for the safe design of the flexible and stretchable sensors.The normal stress and shear stress equations in the constructed structure of the sensors are obtained by the proposed model.The stress distribution in the structure is investigated when bending load is applied to the structures.The numerical results show that the proposed model can predict the variation of normal stress and shear stress along the thickness of the strain-isolation(polydimethylsiloxane)layer accurately.The results by the proposed model are in good agreement with the finite element method,in which the normal stress is variable while the shear stress is invariable along the thickness direction of strain-isolation layer.The high-order model is proposed to predict the stresses of the layered structure of the flexible and stretchable sensor for monitoring the status of the foldable airfoil. 展开更多
关键词 flexible and stretchable sensors higher-order shear-lag model normal stress shear stress
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Robust Adaptive Gain Higher Order Sliding Mode Observer Based Control-constrained Nonlinear Model Predictive Control for Spacecraft Formation Flying 被引量:9
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作者 Ranjith Ravindranathan Nair Laxmidhar Behera 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第1期367-381,共15页
This work deals with the development of a decentralized optimal control algorithm, along with a robust observer,for the relative motion control of spacecraft in leader-follower based formation. An adaptive gain higher... This work deals with the development of a decentralized optimal control algorithm, along with a robust observer,for the relative motion control of spacecraft in leader-follower based formation. An adaptive gain higher order sliding mode observer has been proposed to estimate the velocity as well as unmeasured disturbances from the noisy position measurements.A differentiator structure containing the Lipschitz constant and Lebesgue measurable control input, is utilized for obtaining the estimates. Adaptive tuning algorithms are derived based on Lyapunov stability theory, for updating the observer gains,which will give enough flexibility in the choice of initial estimates.Moreover, it may help to cope with unexpected state jerks. The trajectory tracking problem is formulated as a finite horizon optimal control problem, which is solved online. The control constraints are incorporated by using a nonquadratic performance functional. An adaptive update law has been derived for tuning the step size in the optimization algorithm, which may help to improve the convergence speed. Moreover, it is an attractive alternative to the heuristic choice of step size for diverse operating conditions. The disturbance as well as state estimates from the higher order sliding mode observer are utilized by the plant output prediction model, which will improve the overall performance of the controller. The nonlinear dynamics defined in leader fixed Euler-Hill frame has been considered for the present work and the reference trajectories are generated using Hill-Clohessy-Wiltshire equations of unperturbed motion. The simulation results based on rigorous perturbation analysis are presented to confirm the robustness of the proposed approach. 展开更多
关键词 Adaptive gain higher order sliding mode observer leader-follower formation nonlinear model predictive control spacecraft formation flying tracking control
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兼顾能力与知识状态的Higher-Order CD-CAT选题方法
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作者 席崇钦 涂冬波 蔡艳 《江西师范大学学报(自然科学版)》 CAS 北大核心 2022年第2期111-117,共7页
Higher-order CD-CAT的选题方法是传统单目标(即只对知识状态自适应)选题方法,这将导致被试能力的测量精度不高.基于此,在高阶模型和PWKL选题方法的框架下,该文开发了适用于Higher-order CD-CAT的新选题方法,该方法在选题时能同时兼顾... Higher-order CD-CAT的选题方法是传统单目标(即只对知识状态自适应)选题方法,这将导致被试能力的测量精度不高.基于此,在高阶模型和PWKL选题方法的框架下,该文开发了适用于Higher-order CD-CAT的新选题方法,该方法在选题时能同时兼顾能力和知识状态.实验结果表明:与传统选题方法相比,新选题方法的能力和知识状态估计精度都更高,并且在题库安全性上也具有明显的优势. 展开更多
关键词 双目标CD-CAT 高阶模型 higher-order CD-CAT 选题方法
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HIGHER ORDER BOUSSINESQ-TYPE EQUATIONS FOR WATER WAVES ON UNEVEN BOTTOM 被引量:1
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作者 王本龙 刘桦 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第6期774-784,共11页
Higher order Boussinesq-type equations for wave propagation over variable bathymetry were derived. The time dependent free surface boundary conditions were used to compute the change of the free surface in time domain... Higher order Boussinesq-type equations for wave propagation over variable bathymetry were derived. The time dependent free surface boundary conditions were used to compute the change of the free surface in time domain. The free surface velocities and the bottom velocities were connected by the exact solution of the Laplace equation. Taking the velocities on half relative water depth as the fundamental unknowns, terms relating to the gradient of the water depth were retained in the inverse series expansion of the exact solution, with which the problem was closed. With enhancements of the finite order Taylor expansion for the velocity field, the application range of the present model was extended to the slope bottom which is not so mild. For linear properties, some validation computations of linear shoaling and Booij' s tests were carried out. The problems of wave-current interactions were also studied numerically to test the performance of the enhanced Boussinesq equations associated with the effect of currents. All these computational results confirm perfectly to the theoretical solution as well as other numerical solutions of the full potential problem available. 展开更多
关键词 higher order Boussinesq model wave-current interaction uneven bottom
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Sliding Mode Control Design via Reduced Order Model Approach 被引量:2
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作者 B.Bandyopadhyay Alemayehu G/Egziabher Abera +1 位作者 S.Janardhanan Victor Sreeram 《International Journal of Automation and computing》 EI 2007年第4期329-334,共6页
This paper presents a design of continuous-time sliding mode control for the higher order systems via reduced order model. It is shown that a continuous-time sliding mode control designed for the reduced order model g... This paper presents a design of continuous-time sliding mode control for the higher order systems via reduced order model. It is shown that a continuous-time sliding mode control designed for the reduced order model gives similar performance for thc higher order system. The method is illustrated by numerical examples. The paper also introduces a technique for design of a sliding surface such that the system satisfies a cost-optimality condition when on the sliding surface. 展开更多
关键词 Sliding mode control order reduction reduced order model higher order system optimal control.
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Opti mal higher order learning adaptive control approach for a class of SISO nonlinear systems 被引量:2
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作者 Ronghu CHI Zhongsheng HOU 《控制理论与应用(英文版)》 EI 2005年第3期247-251,共5页
In this paper, an optimal higher order learning adaptive control approach is developed for a class of SISO nonlinear systems. This design is model-free and depends directly on pseudo-partial-derivatives derived on-lin... In this paper, an optimal higher order learning adaptive control approach is developed for a class of SISO nonlinear systems. This design is model-free and depends directly on pseudo-partial-derivatives derived on-line from the input and output information of the system. A novel weighted one-step-ahead control criterion function is proposed for the control law. The convergence analysis shows that the proposed control law can guarantee the convergence under the assumption that the desired output is a set point. Simulation examples are provided for nonlinear systems to illustrate the better performance of the higher order learning adaptive control. 展开更多
关键词 Optimization higher order Learning adaptive control model-flee Nonlinear system
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Influence of higher-order ionospheric delay correction on GPS precise orbit determination and precise positioning 被引量:6
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作者 Zhimin Liu Yangyang Li +1 位作者 Jinyun Guo Fei Li 《Geodesy and Geodynamics》 2016年第5期369-376,共8页
At present, Global Navigation Satellite Systems(GNSS) users usually eliminate the influence of ionospheric delay of the first order items by dual-frequency ionosphere-free combination. But there is still residual io... At present, Global Navigation Satellite Systems(GNSS) users usually eliminate the influence of ionospheric delay of the first order items by dual-frequency ionosphere-free combination. But there is still residual ionospheric delay error of higher order term. The influence of the higher-order ionospheric corrections on both GPS precision orbit determination and static Precise Point Positioning(PPP) are studied in this paper. The influence of higher-order corrections on GPS precision orbit determination, GPS observations and static PPP are analyzed by neglecting or considering the higher-order ionospheric corrections by using a globally distributed network which is composed of International GNSS Service(IGS) tracking stations. Numerical experimental results show that, the root mean square(RMS) in three dimensions of satellite orbit is 36.6 mme35.5 mm. The maximal second-order ionospheric correction is 9 cm, and the maximal third-order ionospheric correction is 1 cm. Higher-order corrections are influenced by latitude and station distribution. PPP is within 3 mm in the directions of east and up. Furthermore, the impact is mainly visible in the direction of north, showing a southward migration trend, especially at the lower latitudes where the influence value is likely to be bigger than 3 mm. 展开更多
关键词 higher-order ionosphere Precision orbit determination PPP Geomagnetic model
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Updated Lagrangian Particle Hydrodynamics (ULPH)Modeling of Natural Convection Problems
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作者 Junsong Xiong Zhen Wang +3 位作者 Shaofan Li Xin Lai Lisheng Liu Xiang Liu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期151-169,共19页
Natural convection is a heat transfer mechanism driven by temperature or density differences,leading to fluid motion without external influence.It occurs in various natural and engineering phenomena,influencing heat t... Natural convection is a heat transfer mechanism driven by temperature or density differences,leading to fluid motion without external influence.It occurs in various natural and engineering phenomena,influencing heat transfer,climate,and fluid mixing in industrial processes.This work aims to use the Updated Lagrangian Particle Hydrodynamics(ULPH)theory to address natural convection problems.The Navier-Stokes equation is discretized using second-order nonlocal differential operators,allowing a direct solution of the Laplace operator for temperature in the energy equation.Various numerical simulations,including cases such as natural convection in square cavities and two concentric cylinders,were conducted to validate the reliability of the model.The results demonstrate that the proposed model exhibits excellent accuracy and performance,providing a promising and effective numerical approach for natural convection problems. 展开更多
关键词 Updated Lagrangian particle hydrodynamics(ULPH) natural convection meshless methods higher order Laplacian model
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Higher-Order Squeezing for Atomic Dipole of a Three-Level Atom in the Kerr-Like Medium Cavity Fields
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作者 卢俊 许毅 董传华 《Journal of Shanghai University(English Edition)》 CAS 2003年第1期49-54,共6页
In this paper, evolution of the higher order squeezing for atomic dipole of three level atom in the Kerr like medium is investigated. The atom discussed has two configurations and is driven by the single mode cohe... In this paper, evolution of the higher order squeezing for atomic dipole of three level atom in the Kerr like medium is investigated. The atom discussed has two configurations and is driven by the single mode coherent state field. Our results show that the squeezing effects are clearly influenced by nonlinear parameters, the initial atom state and the detuning. 展开更多
关键词 J C model higher order squeezing three level atom atomic dipole moment.
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Higher-order topological corner states and origin in monolayer LaBrO
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作者 Qing Wang Ning Hao 《Chinese Physics B》 SCIE EI CAS 2024年第12期149-153,共5页
Intrinsic higher-order topological insulators driven solely by orbital coupling are rare in electronic materials.Here,we propose that monolayer LaBrO is an intrinsic two-dimensional second-order topological insulator.... Intrinsic higher-order topological insulators driven solely by orbital coupling are rare in electronic materials.Here,we propose that monolayer LaBrO is an intrinsic two-dimensional second-order topological insulator.The generalized second-order topological phase arises from the coupling between the 5d orbital of the La atom and the 2p orbital of the O atom.The underlying physics can be thoroughly described by a four-band generalized higher-order topological model.Notably,the edge states and corner states of monolayer LaBrO exhibit different characteristics in terms of morphology,number,and location distribution under different boundary and nanocluster configurations.Furthermore,the higher-order topological corner states of monolayer LaBrO are robust against variations in spin-orbit coupling and different values of Hubbard U.This provides a material platform for studying intrinsic 2D second-order topological insulators. 展开更多
关键词 second order topological insulator first-principles calculations higher order topological model zero-dimensional corner state
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Solitary wave solution to Aw-Rascle viscous model of traffic flow 被引量:1
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作者 吴春秀 张鹏 +2 位作者 S.C.WONG 乔殿梁 戴世强 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2013年第4期523-528,共6页
A traveling wave solution to the Aw-Rascle traffic flow model that includes the relaxation and diffusion terms is investigated. The model can be approximated by the well-known Kortweg-de Vries (KdV) equation. A nume... A traveling wave solution to the Aw-Rascle traffic flow model that includes the relaxation and diffusion terms is investigated. The model can be approximated by the well-known Kortweg-de Vries (KdV) equation. A numerical simulation is conducted by the first-order accurate Lax-Friedrichs scheme, which is known for its ability to capture the entropy solution to hyperbolic conservation laws. Periodic boundary conditions are applied to simulate a lengthy propagation, where the profile of the derived KdV solution is taken as the initial condition to observe the change of the profile. The simulation shows good agreement between the approximated KdV solution and the numerical solution. 展开更多
关键词 hyperbolic conservation law higher-order traffic flow model traveling wave solution conservative scheme
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人机争论探究法:一种争论式智能会话机器人支持的学生高阶思维能力培养模式探索 被引量:10
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作者 李海峰 王炜 《电化教育研究》 CSSCI 北大核心 2024年第3期106-112,128,共8页
大量学生利用生成式人工智能生成作业,导致了学生高阶思维能力难以有效培养。在人机会话中嵌入“争论噪音”,将是解决这一问题的可能途径。研究采用准实验研究设计,基于高阶思维、建构主义和争论学习理论,利用文心一言、学习分析和腾讯Q... 大量学生利用生成式人工智能生成作业,导致了学生高阶思维能力难以有效培养。在人机会话中嵌入“争论噪音”,将是解决这一问题的可能途径。研究采用准实验研究设计,基于高阶思维、建构主义和争论学习理论,利用文心一言、学习分析和腾讯QQ等技术工具,开发了争论式智能会话机器人,构建了人机争论探究法教学模式。结果表明,实验组的学习成绩、批判性思维能力、问题解决能力和学习态度显著优于对照组,但是创新能力效果不显著。为提高人机争论学习效果,教师需要构建特定的高阶思维学习支架,优化人机争论学习的算法机制,培养学生的人机争论素养,研制师生机三元协同争论机制。 展开更多
关键词 生成式人工智能 高阶思维 教学模式 人机协同 智能教育
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Monte Carlo study of single-barrier structure based on exclusion model full counting statistics
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作者 陈华 杜磊 +3 位作者 曲成立 何亮 陈文豪 孙鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期553-556,共4页
Different from the usual full counting statistics theoretical work that focuses on the higher order cumulants computation by using cumulant generating function in electrical structures, Monte Carlo simulation of singl... Different from the usual full counting statistics theoretical work that focuses on the higher order cumulants computation by using cumulant generating function in electrical structures, Monte Carlo simulation of single-barrier structure is performed to obtain time series for two types of widely applicable exclusion models, counter-flows model, and tunnel model. With high-order spectrum analysis of Matlab, the validation of Monte Carlo methods is shown through the extracted first four cumulants from the time series, which are in agreement with those from cumulant generating function. After the comparison between the counter-flows model and the tunnel model in a single barrier structure, it is found that the essential difference between them consists in the strictly holding of Pauli principle in the former and in the statistical consideration of Pauli principle in the latter. 展开更多
关键词 Monte Carlo simulation higher order cumulant exclusion model full counting statistics
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A theoretical extraction scheme of transport information based on exclusion models
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作者 陈华 杜磊 +4 位作者 曲成立 李伟华 何亮 陈文豪 孙鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期566-570,共5页
In order to explore how to extract more transport information from current fluctuation, a theoretical extraction scheme is presented in a single barrier structure based on exclusion models, which include counter-flows... In order to explore how to extract more transport information from current fluctuation, a theoretical extraction scheme is presented in a single barrier structure based on exclusion models, which include counter-flows model and tunnel model. The first four cumulants of these two exclusion models are computed in a single barrier structure, and their characteristics are obtained. A scheme with the help of the first three cumulants is devised to check a transport process to follow the counter-flows model, the tunnel model or neither of them. Time series generated by Monte Carlo techniques is adopted to validate the abstraction procedure, and the result is reasonable. 展开更多
关键词 transport information extraction higher order cumulant exclusion model full counting statistics
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用T4C模式培养高阶能力:对杜威教学法的重建 被引量:2
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作者 彭正梅 陈丽莎 王凯 《开放教育研究》 CSSCI 北大核心 2024年第2期49-58,22,共11页
约翰·杜威的五步教学法在教育领域具有重要意义。本研究重新审视了杜威的五步教学法,强调该教学法忽视的杜威哲学中的要素:民主、共同体中的交流与合作、对工具的使用、对结果的反思,以及最终作品的产生和共同体的改善。本文通过... 约翰·杜威的五步教学法在教育领域具有重要意义。本研究重新审视了杜威的五步教学法,强调该教学法忽视的杜威哲学中的要素:民主、共同体中的交流与合作、对工具的使用、对结果的反思,以及最终作品的产生和共同体的改善。本文通过深入研究杜威著作,结合其中蕴含的其他重要要素提出了T4C模式。T4C模式强调个体的探究性学习(C1代表批判性思维和问题解决,杜威称之为反思性思维或实践)是在共同体中利用工具(Tools,如概念、技术等)以合作(C2)和交流(C3)的方式开展的。这种探究性学习的预期结果是获得创造性的新体验和新工具(C4)。T4C模式为现代社会所迫切需要的工具使用能力、批判性思维、交流能力、合作能力和创新能力等高阶能力,提供了培养框架,其本质在于用高阶能力培养高阶能力,有助于实现杜威社会政治理想中民主与教育的根本关联。 展开更多
关键词 杜威五步教学法 高阶能力 4C能力 反思性思维 探究 T4C模式
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Two-Photon Nonlinear Jaynes-Cummings Model with Stark Shift
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作者 董传华 卢俊 《Journal of Shanghai University(English Edition)》 CAS 2002年第3期196-202,共7页
Two photon Jaynes Cummimgs model is generalized to the case of Kerr medium in this paper. The field and atom are prepared initially in two photon superposition state and ground state respectively. Nonlinear coeffic... Two photon Jaynes Cummimgs model is generalized to the case of Kerr medium in this paper. The field and atom are prepared initially in two photon superposition state and ground state respectively. Nonlinear coefficient affects the dynamic behaviors of the field and atom. Evolutions of the squeezing for the operators of field and atom and the quantum inversion are discussed. In particular, the higher order squeezing for atomic dipole and the effects of nonlinearity on it, which have not been studied by other authors, are investigated. Increasing the nonlinear coefficient will decrease the squeezing depth of atomic dipole. 展开更多
关键词 J C model SQUEEZING higher order squeezing quantum inversion.
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A Novel Parsimonious Neurofuzzy Model Applied to Railway Carriage System Identification and Fault Diagnosis 被引量:1
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作者 S.C.Zhou O.L.Shuai +1 位作者 T.T.Wong T.P.Leung 《International Journal of Plant Engineering and Management》 1997年第4期7-11,共5页
In this paper, we suggest a novel parsimonious neurofuzzy model realized by RBFNs for railway carriage system identification and fault diagnosis. To overcome the curse of dimensionality resulting from high dimensional... In this paper, we suggest a novel parsimonious neurofuzzy model realized by RBFNs for railway carriage system identification and fault diagnosis. To overcome the curse of dimensionality resulting from high dimensional input variables, in our developed model the features extracted from the available observations are regarded as the input variables by adopting the higher-order statistics(HOS) technique. Such a constructed model is also applied to a practical railway carriage system, simulation results indicate that the developed neurofuzzy model possesses strong identification and fault diagnosis ability. 展开更多
关键词 parsimonious neurofuzzy model feature extraction by higher-order Statistics (HOS) railway carriage system identification and fault diagnosis
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智能群体多维感知机器人支持的人机协同研学教学模式--以“孔子”大语言模型会话机器人的研发与教学为例
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作者 李海峰 李广鑫 汤允凤 《现代远距离教育》 CSSCI 2024年第4期48-59,共12页
在大语言模型教育应用中,人机会话反馈形式单一问题一直未得到较好解决,这严重影响了学生的高阶思维能力培养。开发具有智能群体多维感知能力的会话机器人,是解决这一问题的重要途径。为此,研究者以群体感知、同伴反馈和研究性学习理论... 在大语言模型教育应用中,人机会话反馈形式单一问题一直未得到较好解决,这严重影响了学生的高阶思维能力培养。开发具有智能群体多维感知能力的会话机器人,是解决这一问题的重要途径。为此,研究者以群体感知、同伴反馈和研究性学习理论为基础,利用文心一言、飞书开发平台和学习分析等技术,开发了智能群体多维感知会话机器人“孔子”,构建了人机协同研学教学模式。教学实验以“现代教育技术应用”课程为教学内容,采用准实验研究设计,邀请数学专业学生参与实验。结果表明,与直接使用文心一言的教学相比,人机协同研学教学模式能显著提升学生的问题解决能力、批判性思维能力、创新能力和外在学习动机,但对学习绩效、内在动机和协作学习能力效果欠佳。为了提高教学效果,研究者需提高多维感知评价精准性、感知维度全面性、情境学习多样性和教师教学技能。 展开更多
关键词 人机协同研学 生成式人工智能 群体感知 高阶思维 大语言模型
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