检索结果-南通市图书馆

同方期刊数据库博看期刊

Two-dimensional face stability analysis in rock masses governed by the Hoek-Brown strength criterion with a new multi-horn mechanism

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2023年第8期33卷 963-976页

作者： junhao Zhong Xiaoli Yang School of Civil Engineering Central South UniversityChangsha 410075China

The face stability problem is a major concern for tunnels excavated in rock masses governed by the Hoek-Brown strength *** provide an accurate prediction for the theoretical solution of the critical face pressure,this study adopts the piecewise linear method(PLM)to account for the nonlinearity of the strength envelope and proposes a new multi-horn rotational mechanism based on the Hoek-Brown strength criterion and the associative flow *** analytical solution of critical support pressure is derived from the energy-work balance equation in the framework of the plastic limit theorem;it is formulated as a multivariable nonlinear optimization problem relying on 2m dependent variables(m is the number of segments).Meanwhile,two classic linearized measures,the generalized tangential technique(GTT)and equivalent Mohr-Coulomb parameters method(EMM),are incorporated into the analysis for ***,the parametric study indicates a significant improvement in support pressure by up to 13%compared with the GTT,and as expected,the stability of the tunnel face is greatly influenced by the rock strength *** stress distribution on the rupture surface is calculated to gain an intuitive understanding of the failure at the limit *** the limit analysis is incapable of calculating the true stress distribution in rock masses,a rough approximation of the stress vector on the rupture surface is *** the end,sets of normalized face pressure are provided in the form of charts for a quick assessment of face stability in rock masses.

关键词： Face stability Piecewise linear method Hoek-Brown strength criterion Multi-horn rotational mechanism Limit analysis

Containment Control of Multi-Agent Systems with Stochastic Multiplicative Noises

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2022年第3期35卷 909-930页

作者： REN junhao ZONG Xiaofeng School of Automation China University of GeosciencesWuhan 430074China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan 430074China Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of EducationWuhan 430074China

This paper investigates the containment problem of continuous-time multi-agent systems with multiplicative noises,where the first-order and second-order multi-agent systems are studied *** on stochastic analysis tools,algebraic graph theory,and Lyapunov function method,the containment protocols based the relative states measurement with multiplicative noises are developed to guarantee the mean square and almost sure ***,the sufficient conditions and necessary conditions related to the control gains are derived for achieving mean square and almost sure *** is also shown that multiplicative noises may works positively for the almost sure containment of the first-order multi-agent *** examples are also introduced to illustrate the effectiveness of the theoretical results.

关键词： Containment control multi-agent system multiplicative noises stochastic system

A Disturbance Rejection Control Approach for Clock Synchronization in IEEE 1588 Networks

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2018年第6期31卷 1437-1448页

作者： ZHANG junhao ZHANG Wenan College of Information Engineering Zhejiang University of TechnologyHangzhou 310023China Zhejiang Provincial United Key Laboratory of Embedded Systems Hangzhou 310023China

This paper is concerned with the clock synchronization problem for IEEE 1588 ***,the synchronization error is described as a bounded disturbance,and a linear extended state observer (LESO)is designed to estimate the lumped disturbance induced by the oscillator frequency drift and timestamps quantization ***,the lumped disturbance is compensated by the proposed *** proposed approach has the advantage that it's able to deal with non-Gaussian disturbance induced by accumulated quantization *** are Drovided to validate the effectiveness and superiority of the proposed approach.

关键词： Feedback control IEEE 1588 linear extended state observer peer-to-peer networks syn-chronization.

Improved Generative Adversarial Behavioral Learning Method for Demand Response and Its Application in Hourly Electricity Price Optimization

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2022年第5期10卷 1358-1373页

作者： junhao Lin Yan Zhang Shuangdie Xu Shanghai Jiao Tong University ShanghaiChina Shibei Electricity Supply Company State Grid Shanghai Municipal Electric Power CompanyShanghaiChina

In response to the imbalance between power generation and demand, demand response(DR) projects are vigorously promoted. However, customers’ DR behaviors are still difficult to be simulated accurately and objectively. To tackle this challenge, we propose a new DR behavioral learning method based on a generative adversary network to learn customers’ DR habits. The proposed method is also extended to maximize the economic revenues of generated DR policies on the premise of obeying customers’ DR habits, which is hard to be realized simultaneously by existing model-based methods and traditional learning-based methods. To further consider customers’ timevarying DR patterns and trace the changes dynamically, we define customers’ DR participation positivity as an indicator of their DR pattern and propose a condition regulation approach improving the natural generative adversary framework to generate DR policies conforming to customers’ current DR patterns. The proposed method is applied to hourly electricity price optimization to reduce the fluctuation of system aggregate loads. An online parameter updating method is also utilized to train the proposed behavioral learning model in continuous DR simulations during electricity price optimization. Finally, numerical simulations are conducted to verify the effectiveness and superiority of the proposed method.

关键词： Demand response behavioral learning reinforcement learning generative adversarial network electricity price optimization

Sufficient conditions and limitations of equivalent partition in multiagent controllability

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2022年第3期65卷 152-166页

作者： junhao GUO Zhijian JI Yungang LIU Shandong Key Laboratory of Industrial Control Technology Institute of Complexity ScienceCollege of Automation Qingdao University School of Control Science and Engineering Shandong University

The emergence of the graphical characterization of multiagent controllability has raised several issues concerning how to directly establish controllability from topology structures. Arguably, one of the most serious challenges to this research field is the means through which equivalent partition, which plays an important role in graphical characterization, obtains sufficient controllability conditions; hence, how equivalent partition influences controllability has garnered considerable attention. This article specifically focuses on the sufficient conditions and limitations of equivalent partition in multiagent controllability. We provide two sufficient conditions:(i) the absence of the system matrix’s eigenvectors that make the equation formed by the eigenvalues and eigenvectors hold and(ii) the addition of leaders by reducing the same number of followers. The first condition particularly exhibits a relation between two apparently unrelated parts: Tao’s equation and controllability. We further propose a necessary and sufficient condition for controllability under n-node graphs(n 5) by taking advantage of iso-neighbor nodes, and analyze the resulting difficulties when n is greater than 5. Immediate corollaries of our results are obtained. Finally, we reveal the limitation of equivalent partition in controllability analysis. Several constructive examples demonstrate our results.

关键词： multiagent system controllability equivalent partition Tao's equation graph theory

同方期刊数据库

Controllability of game-based multi-agent system

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第12期66卷 107-120页

作者： junhao GUO Zhijian JI Yungang LIU Institute of Complexity Science College of AutomationQingdao University School of Control Science and Engineering Shandong University

We introduce a strategy matrix, a novel concept for ensuring controllability in game-based control systems(GBCSs). This graph-based condition is presented as an alternative to utilizing complex mathematical calculations through algebraic conditions. Moreover, to address these issues, one must first study the expression of Nash equilibrium actions. This expression yields a general formula of the game controllability matrix, which is always affected by the specific matrix(strategy matrix) comprising Nash equilibrium actions, and the matrix can not only be obtained by matrix calculation but can also be directly written through the topology, indicating the topology’s specific influence on the GBCS. Finally, we build a new game-based multi-agent system and determine the controllability relationship between the system and the general system.

关键词： controllability game-based control system topological structure equivalent partition

Micro-mechanical model for predicting the elasto-plastic behavior of composites based on secant formulation method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第1期34卷 281-295页

作者： junhao LIANG Xinhai HE Wenlong TIAN School of Materials Science&Engineering Xi'an Polytechnic UniversityXi'an 710048China Shaanxi Key Laboratory of Surface Engineering and Remanufacturing Xi'an UniversityXi'an 710048China School of Mechanical Engineering Northwestern Polytechnical UniversityXi'an 710072China

To predict the Elasto-Plastic Behaviors(EPBs)of aligned inclusions reinforced composites,this paper develops an interpolative Mori-Tanaka/Double-Inclusion(MT-DI)homogenization model with the secant formulation,and gives the numerical implementation algorithms of the developed MT-DI model with the secant *** Finite Element(FE)homogenization method is implemented to provide the "exact" EPBs of the composites and thus validate the MT-DI model with the secant *** MT-DI model with the 2 nd-order secant formulation is validated to provide the more accurate predictions,while the MT-DI model with the 1 st-order secant formulation always gives the stiffer *** results show that using the macro-stress and macrostrain as the inputs,the MT-DI model with the secant formulation gives the identical *** predictions of the MT-DI model with the secant formulation vary between those of the MT and DI models with the secant ***,the MT-DI model with the secant formulation does not predict the accurate EPBs for the phases of the composites.

关键词： Elasto-plastic behavior FE homogenization Mean-field homogenization MT-DI model Secant formulation

Energy-Efficient Optimal Guaranteed Cost Intermittent-Switch Control of a Direct Expansion Air Conditioning System

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2021年第11期8卷 1852-1866页

作者： Jun Mei Zhenyu Lu junhao Hu Yuling Fan School of Mathematics and Statistics South-Central University for NationalitiesWuhan 430074China School of Electronic and Information Engineering Nanjing University of Information Science and TechnologyNanjing 210044China College of Informatics Huazhong Agricultural UniversityWuhan 430072China

To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The control strategy consists of an open loop optimization controller and a closed-loop guaranteed cost periodically intermittent-switch controller(GCPISC). The error dynamics system of the closed-loop control is modelled based on the GCPISC principle. The difference,compared to the previous DX A/C system control methods, is that the controller designed in this paper performs control at discrete times. For the ease of designing the controller, a series of matrix inequalities are derived to be the sufficient conditions of the lower-layer closed-loop GCPISC controller. In this way, the DX A/C system output is derived to follow the optimal references obtained through the upper-layer open loop controller in exponential time, and the energy efficiency of the system is improved. Moreover, a static optimization problem is addressed for obtaining an optimal GCPISC law to ensure a minimum upper bound on the DX A/C system performance considering energy efficiency and output tracking error. The advantages of the designed hierarchical controller for a DX A/C system with uncertain parameters are demonstrated through some simulation results.

关键词： Energy efficiency hierarchical control open loop optimal control optimal guaranteed cost periodically intermittent-switch control

Freeness and matrix decompositions

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2011年第11期54卷 2309-2327页

作者： GE Liming SHEN junhao Academy of Mathematics and System Science Chinese Academy of Sciences Beijing 100190 China Department of Mathematics University of New Hampshire Durham NH 03824 USA

If a semicircular element and the diagonal subalgebra of a matrix algebra are free in a finite von Neumann algebra （with respect to a normal trace）, then, up to the conjugation by a diagonal unitary element, all entries of the semicircular element are uniquely determined in the sense of （joint） distribution. Suppose a selfadjoint element is free with the diagonal subalgebra. Then, in the matrix decomposition of the selfa^tjoint element, any two entries cannot be free with each other unless the selfadjoint element is semicircular. We also define a ＂matricial distance＂ between two elements and show that such distance for two free semicircular elements in a finite von Neumann algebra is nonzero and independent of the properties of the von Neumann algebra.

关键词： von Neumann algebra factor semicircular element joint distribution