检索结果-内蒙古大学图书馆

SSRN 2024年

作者： Rajendran, Barathan Chen, Xiao Wang, Xin Wu, Tao Goh, Kek Boon Department of Mechanical Engineering School of Engineering Monash University Malaysia Jalan Lagoon Selatan Bandar Sunway Selangor 47500 Malaysia Institute of Biomechanics and Medical Engineering Department of Engineering Mechanics Tsinghua University Beijing100084 China School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi’an710072 China MIIT Key Laboratory of Dynamics and Control of Complex Systems Xi’an710072 China

Understanding the fundamental mechanism of shrink hydrogel sensors necessitates a complete comprehension of analyte-centered multivalent binding that occurs within their salt-rich microenvironments. However, the mechanics and thermodynamics governing this phenomenon remain insufficiently understood. Here, we derive a theoretical framework that examines the formation of temporary cross–links between the polymeric chains induced by the specific binding interaction between the fixed receptors and the multivalent analytes. As a highlight of our theory, we use statistical thermodynamics to characterize the analyte transport and these multivalent complexations, allowing us to subsequently determine the mechanics of the shrinkage experienced by these hydrogel sensors. Consequently, our theory unveils the valency of the bindings, setting an upper bound for the performance of these shrink sensors;i.e., tuning the receptor density allows us to further modulate their performance. In summary, our theory tightly correlates the microscopic properties of the analyte and hydrogel to the macroscopic shrinking properties of these sensors, hence facilitating a structured design and optimization regime for advanced biomedical applications. © 2024, The Authors. All rights reserved.

关键词： Shrinkage

来源：评论

学校读者我要写书评

暂无评论

Averaging principle of stochastic Burgers equation driven by Lévy processes

arXiv

引用

arXiv 2021年

作者： Yue, Hongge Xu, Yong Wang, Ruifang Jiao, Zhe School of Mathematics and Stochastics Northwestern Polytechnical University Xi'an710072 China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi'an710072 China

We are concerned about the averaging principle for the stochastic Burgers equation with slow-fast time scale. This slow-fast system is driven by Lévy processes. Under some appropriate conditions, we show that the slow component of this system strongly converges to a limit, which is characterized by the solution of stochastic Burgers equation whose coefficients are averaged with respect to the stationary measure of the fast-varying jump-diffusion. To illustrate our theoretical result, we provide some numerical *** Codes 60H15, 70K65, 70K70, 34G20 Copyright © 2021, The Authors. All rights reserved.

关键词： Stochastic systems

来源：评论

学校读者我要写书评

暂无评论

Elastic Wave Propagation in Nonlinear Two-dimensional Acoustic Metamaterials

Research Square

引用

Research Square 2021年

作者： Zhao, Cheng Zhang, Kai Zhao, Pengcheng Deng, Zichen School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi’an710072 China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi’an710072 China

This study describes the wave propagation in a periodic lattice which is formed by a spring-mass two-dimensional structure with local Duffing nonlinear resonators. The wave propagation characteristics of the system is evaluated by using the perturbation method and Floquet-Bloch theorem to determine the dispersion relationships and wave propagation characteristics in the nonlinear two-dimensional acoustic metamaterials (2D AM). A quantitative study of wave amplitude is carried out to reveal the limits of the proposed method. In particular, the harmonic balance method is introduced to investigate the frequency response and effective mass of the nonlinear systems. We find that the dispersion relations, group velocity, negative effective mass of unit-cell are related to wave amplitude. Furthermore, the dual wave vector, bifurcation of periodic solutions and chaotic band are observed in the nonlinear systems. The results can be used to tune wave propagation in the nonlinear acoustic metamaterials and provide some ideas for the study of nonlinear metamaterials. © 2021, CC BY.

关键词： Frequency response

来源：评论

学校读者我要写书评

暂无评论

Soft-Landing dynamics of a Type of Four-Legged Space Lander

SSRN

引用

SSRN 2024年

作者： Shi, Tengfei Shi, Tengfei Yang, Yinping Zhang, Zhijuan Liu, Cuicui Liu, Caishan Ma, Daolin Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace Engineering Southwest Jiaotong University Chengdu610031 China State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Beijing100871 China Institute of Dynamics and Control College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology Beijing100871 China China Academy of Space Technology Beijing100094 China School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai200240 China Key Laboratory of Marine Intelligent Equipment and System Ministry of Education Shanghai200240 China

Analyzing the landing dynamics response is essential for enhancing the success rate of surface explorations on Mars, the moon, or asteroids. This paper develops a comprehensive dynamics model for a space lander equipped with four sets of buffer legs, each consisting of a primary strut, two secondary struts, and a footpad, during its soft landing process. The degrees of freedom of the main body and the footpads are defined as generalized coordinates to describe the motion of the space lander. The compression force of the buffer struts is obtained by interpolating real experimental data, and the contact force between the footpad and the ground is calculated using Archimedes law for granular media. Then, the dynamical model for the lander in terms of minimal degrees of freedom can be constructed by applying the Lagrange equations of the second kind. The proposed dynamics model is validated by the experiments of a single-legged lander vertical touchdown and a four-legged lander free touchdown. Moreover, histories of buffer force, acceleration of the main body, and other key physical quantities are computed to investigate the landing process. This highly efficient and accurate dynamics model provides a method to perform extensive simulations to design and optimize a soft landing process. © 2024, The Authors. All rights reserved.

关键词： Landing

来源：评论

学校读者我要写书评

暂无评论

Iteration complexity analysis of a partial LQP-based alternating direction method of multipliers

arXiv

引用

arXiv 2021年

作者： Bai, Jianchao Ma, Yuxue Sun, Hao Zhang, Miao School of Mathematics and Statistics MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi’an710129 China Department of Mathematics Louisiana State University Baton RougeLA70803-4918 United States

In this paper, we consider a prototypical convex optimization problem with multi-block variables and separable structures. By adding the Logarithmic Quadratic Proximal (LQP) regularizer with suitable proximal parameter to each of the first grouped subproblems, we develop a partial LQP-based Alternating Direction Method of Multipliers (ADMM-LQP). The dual variable is updated twice with relatively larger stepsizes than the classical region (0, 1+√5). Using a prediction-correction approach to analyze properties of the iterates 2 generated by ADMM-LQP, we establish its global convergence and sublinear convergence rate of O(1/T) in the new ergodic and nonergodic senses, where T denotes the iteration index. We also extend the algorithm to a nonsmooth composite convex optimization and establish similar convergence results as our ADMM-LQP. © 2021, CC BY.

关键词： Convex optimization

来源：评论

学校读者我要写书评

暂无评论

Electrical activities of neural systems exposed to sinusoidal induced electric field with random phase

引用

Science China(Technological Sciences) 2019年第7期62卷 1141-1150页

作者： DU Lin CAO ZiLu LEI YouMing DENG ZiChen School of Natural and Applied Science Northwestern Polytechnical University Xi'an 710129 China MIIT Key Laboratory of Dynamics and Control of Complex Systems Xi'an 710129 China School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi 'an 710129 China

The brain neural system is often disturbed by electromagnetic and noise environments, and research on dynamic response of its interaction has received extensive attention. This paper investigates electrical activity of Morris-Lecar neural systems exposed to sinusoidal induced electric field(IEF) with random phase generated by electromagnetic effect. By introducing a membrane depolarization model under the effect of random IEF, transition state of firing patterns, including mixed-mode oscillations(MMOs) with layered inter-spike intervals(ISI) and intermittency with a power law distribution in probability density function of ISI, is obtained in a single neuron. Considering the synergistic effects of frequency and noise, coherence resonance is performed by phase noise of IEF under certain parameter conditions. For the neural network without any internal coupling, we demonstrate that synchronous oscillations can be induced by IEF coupling, and suppression of synchronous spiking is achieved effectively by phase noise of IEF. Results of the study enrich the dynamical response to electromagnetic induction and provide insights into mechanisms of noise affecting information coding and transmission in neural systems.

关键词： induced electric field random phase electrical activity transition coherence resonance synchronous suppression

来源：评论

学校读者我要写书评

暂无评论

Statistical solution to SDEs with α -stable Lévy noise via deep neural network

引用

International Journal of dynamics and control 2020年第4期8卷 1129-1140页

作者： Zhang, Hao Xu, Yong Li, Yongge Kurths, Jürgen Department of Applied Mathematics Northwestern Polytechnical University Xian710072 China Department of Engineering Mechanics Northwestern Polytechnical University Xian710072 China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xian710072 China Potsdam Institute for Climate Impact Research Potsdam14412 Germany Department of Physics Humboldt University Berlin Berlin12489 Germany

The probability density function of the stochastic differential equations with α-stable Lévy noise is determined by the deterministic fractional FokkerPlanck (FFP) equation with the Riesz fractional derivative. In this paper, to solve the FFP equation, a new algorithm which is an efficient numerical approach using the deep neural network is proposed in view of the mesh-dependence phenomenon in the traditional discrete scheme and the nonsmooth solution of the Monte Carlo method. Under the framework of the DL-FP algorithm, the "fractional centered derivative" approach is applied to approximate the Riesz fractional derivative of the output in the neural network, which is the major novelty of this approach. Numerical results are presented to demonstrate the accuracy of the approach. Comparing with the traditional discrete scheme and the Monte Carlo method, the proposed algorithm is mesh-less and smoother. Furthermore, the proposed technique performs well in dealing with the heavy-tail case through comparing with the analytical solution. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.

关键词： Deep neural networks

来源：评论

学校读者我要写书评

暂无评论

Particle swarm optimization-based algorithm of a symplectic method for robotic dynamics and control

引用

Applied Mathematics and Mechanics(English Edition) 2019年第1期40卷 111-126页

作者： Zhaoyue XU Lin DU Haopeng WANG Zichen DENG School of Natural and Applied Science Northwestern Polytechnical University School of Aeronautics Northwestern Polytechnical University Ministry of Industry and Information Technology(MIIT) Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Department of Engineering Mechanics Northwestern Polytechnical University

Multibody system dynamics provides a strong tool for the estimation of dynamic performances and the optimization of multisystem robot design. It can be described with differential algebraic equations(DAEs). In this paper, a particle swarm optimization(PSO) method is introduced to solve and control a symplectic multibody system for the first time. It is first combined with the symplectic method to solve problems in uncontrolled and controlled robotic arm systems. It is shown that the results conserve the energy and keep the constraints of the chaotic motion, which demonstrates the efficiency, accuracy, and time-saving ability of the method. To make the system move along the pre-planned path, which is a functional extremum problem, a double-PSO-based instantaneous optimal control is introduced. Examples are performed to test the effectiveness of the double-PSO-based instantaneous optimal control. The results show that the method has high accuracy, a fast convergence speed, and a wide range of *** the above verify the immense potential applications of the PSO method in multibody system dynamics.

关键词： robotic dynamics multibody system symplectic method particle swarm optimization(PSO)algorithm instantaneous optimal control

来源：评论

学校读者我要写书评

暂无评论

Kinetostatic Modeling of Compliant Mechanisms Via Reduced-Mode Cosserat Rod Model

SSRN

引用

SSRN 2023年

作者： Wu, Ke Wang, Wei Li, Xin Hu, Junzhe Chen, Pengyu Cheng, Ran Sun, Qidi Liu, Lifu Zhou, Luna Xu, Xin Zhang, Shucheng Deng, Zicheng Chen, Rui Zheng, Gang INRIA Lille-Nord Europe 40 Avenue Halley Villeneuve d’Ascq59650 France State Key Laboratory of Mechanical Transmission University of Chongqing Chongqing400030 China LS2N - équipe ReV - Robotique Et Vivant Institut Mines Telecom Atlantique Nantes France Chongqing University China Chongqing University University of Cincinnati Joint Co-op Institute Chongqing University Chongqing400044 China Center for Robotics Research University of Cincinnati CincinnatiOH45221 United States MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi’an710072 China Hong Kong

Compliant mechanisms (CMs), which are normally composed of rigid blocks and flexible members, utilize the elastic deflection of all these built-in flexible members, totransfer motion, force and energy. In the current literature, geometrically nonlinear Euler Bernoulli beam theory and its related methods are commonly used for modelingthese flexible members. However, its governing ordinary differential equation (ODE) only considers the main contributor to beam deflections: bending, without taking careof shear and axial stretch along the beam. To take care of more possible strains, Cosserat rod theory, serves as a better alternative for high accuracy. However, it stillsuffers from relatively complex modeling and time-consuming computation. In this paper, we propose a reduced-mode Cosserat rod model to bypass the need ofconducting complex modeling, providing a more compact formulation. The detailed derivations are presented step by step, and we also propose a mode selectionmethod to meet the requirements of different engineering scenarios. Numerical examples are provided to verify the reduced-mode model as well as the feasibility ofmodeling CMs. In particular, modeling flexible springs and related mechanisms has been proved valid via this proposed model. © 2023, The Authors. All rights reserved.

关键词： Boundary value problems

来源：评论

学校读者我要写书评

暂无评论

Kirigami-inspired rigid-foldable meta-structure with a bidirectional self-locking property

引用

Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 2025年第2315期481卷

作者： Li, Jihui An, Siqi Wu, Xinwei Deng, Dongxuan Deng, Zichen School of Mechanics Civil Engineering and Architecture MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi'an710072 China Department of Engineering Mechanics Zhejiang University Hangzhou310027 China School of Information Mechanics and Sensing Engineering Xidian University Xi'an710071 China

Self-locking is an attractive feature in origami structures that enables the foldable structure to withstand loads along the direction of deployment, without requiring extra locking elements. However, this feature is rarely observed in rigid origami because such structures can be easily folded or deployed along the deployment direction. Here, we introduce a novel origami meta-structure with both rigid foldability and bidirectional self-locking capacity based on a kirigami-inspired foldable icosahedron. The kinematic analysis demonstrates that a foldable icosahedron has two motion steps separated by a bifurcation point. By stacking two icosahedra together, we construct a rigid-foldable module capable of bearing both tensile and compressive loads along the direction of deployment. Through energy analysis and prototype experiments, we demonstrate that the bidirectional self-locking phenomenon originates from both the multiple motion steps of a foldable icosahedron and the torsional stiffness of creases. We arrange the module into a planar array and show its potential application in mechanical memory storage devices. This work paves a new way to design rigid-foldable and bidirectional self-locking origami structures. © 2025 The Author(s).

关键词： Digital arithmetic

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：