An Asynchronous Operation Approach to Event-Triggered Control for Fuzzy Markovian Jump Systems With General Switching Policies

Cheng, Jun,Park, Ju H.,Zhang, Lixian,Zhu, Yanzheng Institute of Electrical and Electronics Engineers, 2018 IEEE transactions on fuzzy systems Vol.26 No.1

<P>This paper investigates the problem of event-triggered control for a class of fuzzy Markov jump systems with general switching policies. A novel event-triggered scheme is proposed to improve the transmission efficiency at each sampling instance. Each transition rate allows to be unknown, known, or only its uncertain domains value is known. With the help of a tailored technique to bind the uncertain terms and an asynchronous operation approach to tackle the fuzzy system and fuzzy controller, sufficient conditions for the resulting fuzzy Markovian jump systems are established in terms of coupled linear matrix inequalities. Finally, an example is given to illustrate the validity of the developed technique.</P>

Quantized _{H ∞} filtering for switched linear parameter-varying systems with sojourn probabilities and unreliable communication channels

Cheng, Jun,Park, Ju H.,Cao, Jinde,Zhang, Dian Elsevier 2018 Information sciences Vol.466 No.-

<P><B>Abstract</B></P> <P>This paper addresses the problem of quantized <SUB> H ∞ </SUB> filtering for switched linear parameter-varying systems with both sojourn probabilities and unreliable communication channels. A more general model is developed, where both the mode-dependent logarithmic quantizer and channel noise are taken into consideration. With the sojourn probability-based switching law and parameterized Lyapunov functional, sufficient criteria promising stochastic stability of switched linear parameter- varying systems are derived. Finally, the results of the simulation show the effectiveness and feasibility of the proposed method.</P>

Event-triggered H _∞ control for T–S fuzzy nonlinear systems and its application to truck–trailer system

Cheng, Jun,Park, Ju H.,Wang, Hailing Elsevier 2016 ISA transactions Vol.65 No.-

<P><B>Abstract</B></P> <P>This paper addresses the problem of event-triggered <SUB> H ∞ </SUB> control for a class of T–S fuzzy nonlinear systems. An improved event-triggered scheme (ETS) characterized by discrete sampling is proposed, where the time-derivative of the membership function is not required. To get conservative conditions, the deviation bound of asynchronous normalized membership functions is considered. By utilizing the non-quadratic fuzzy line-integral Lyapunov functions and a free-matrix-based integral inequality, novel criteria for stabilization analysis of T–S fuzzy nonlinear systems are established. Finally, a truck–trailer system is provided to show the effectiveness of the proposed theories.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An improved discrete event-triggered scheme is proposed. </LI> <LI> Some novel criteria for stabilization analysis of T–S fuzzy nonlinear systems are established. </LI> <LI> A truck–trailer system is studied to show the effectiveness and superiority of the proposed theories. </LI> </UL> </P>

Frequency Regulation Strategy for AC–DC System During Black Start

Chengjun Xia,Jiazheng Xie,Haiwen Lan,Baorong Zhou,Zhaobin Du 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

High-voltage direct current (HVDC) can speed up the recovery of a power system. However, both rectifer and inverter sides of HVDC are weak systems during a black start. To coordinate frequency characteristics of both sides within the frequency deviation constrain, a frequency regulation strategy for AC–DC system during a black start is proposed. First, the mathematical models of asynchronous interconnected AC–DC system are established, and the optimal HVDC transmission power leading to minimum frequency deviation of both sides is obtained based on the linear quadratic optimal control method. To adapt to the continuously changing parameters and confgurations of the AC power system during a black start, a Narendra adaptive tracking control method is developed to obtain the control law of the target value of governor, which allows the actual system frequency follow the reference system frequency under the optimal HVDC transmission power. Finally, the simulation model is established using PSCAD/EMTDC software to verify the proposed strategy

CONTINUITY OF (α, β)-DERIVATIONS OF OPERATOR ALGEBRAS

Chengjun Hou,Qing Meng 대한수학회 2011 대한수학회지 Vol.48 No.4

We investigate the continuity of (α, β)-derivations on B(X)or C*-algebras. We give some sufficient conditions on which (α, β)-derivations on B(X) are continuous and show that each (α, β)-derivation from a unital C*-algebra into its a Banach module is continuous when α and β are continuous at zero. As an application, we also study the ultraweak continuity of (α, β)-derivations on von Neumann algebras.

First‑Principles Study on Stacking Fault Energy of γ‑Fe–Mn Alloys

Chengjun Wang,Wujie Zu,Hao Wang,Yang Wang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.9

The ground state properties and generalized stacking fault energy (GSFE) of γ-Fe–Mn alloys with different Mn concentrationsare calculated by ab initio simulation. The calculation results of intrinsic stacking fault energies (ISFE) show that Mn atomshave a significant short-range effect on the ISFE; the parabolic relationship between ISFE and Mn atom concentration ofantiferromagnetic (AFM) Fe–Mn alloys is explained by the cohesive energy and density of states (DOS) of the alloys. AFMincreases ISFE of γ-Fe–Mn alloys compared to non-magnetic (NM). The importance of considering magnetic interactionsin ISFE of γ-Fe–Mn alloys is proven and it is very significant to study the deformation behavior of medium manganese steel.

Hilbert transform based approach to improve extraction of “drive-by” bridge frequency

Chengjun Tan,Nasim Uddin 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.3

Recently, the concept of"drive-by" bridge monitoring system using indirect measurements from a passing vehicle to extract key parameters of a bridge has been rapidly developed. As one of the most key parameters of a bridge, the natural frequency has been successfully extracted theoretically and in practice using indirect measurements. The frequency of bridge is generally calculated applying Fast Fourier Transform (FFT) directly. However, it has been demonstrated that with the increase in vehicle velocity, the estimated frequency resolution of FFT will be very low causing a great extracted error. Moreover, because of the low frequency resolution, it is hard to detect the frequency drop caused by any damages or degradation of the bridge structural integrity. This paper will introduce a new technique of bridge frequency extraction based on Hilbert Transform (HT) that is not restricted to frequency resolution and can, therefore, improve identification accuracy. In this paper, deriving from the vehicle response, the closed-form solution associated with bridge frequency removing the effect of vehicle velocity is discussed in the analy tical study. Then a numerical Vehicle-Bridge Interaction (VBI) model with a quarter car model is adopted to demonstrate the proposedapproach. Finally, factors that affect the proposed approach are studied, including vehicle velocity, signal noise, and road roughness profile.

$C^*$-algebra of local conjugacy equivalence relation on strongly irreducible subshift of finite type

Chengjun Hou,Xiangqi Qiang 대한수학회 2024 대한수학회보 Vol.61 No.1

Let $G$ be an infinite countable group and $A$ be a finite set. If $ \Sigma \subseteq A^{G}$ is a strongly irreducible subshift of finite type and $\mathcal{G}$ is the local conjugacy equivalence relation on $ \Sigma$. We construct a decreasing sequence $\mathcal{R}$ of unital $C^*$-subalgebras of $C(\Sigma)$ and a sequence of faithful conditional expectations $\mathcal{E}$ defined on $C(\Sigma)$, and obtain a Toeplitz algebra $\mathcal{T}(\mathcal{R},\mathcal{E})$ and a $C^*$-algebra $C^*(\mathcal{R},\mathcal{E})$ for the pair $(\mathcal{R},\mathcal{E})$. We show that $C^*(\mathcal{R},\mathcal{E})$ is $\ast$-isomorphic to the reduced groupoid $C^*$-algebra $C_r^*(\mathcal{G})$.

Mechanism of Packing Rigidity Gain in Sand Aging: From the Perspective of Structural Order Evolution

Chengjun Liu,Pei Tai,Zhaofeng Li,Wenbiao Hu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.6

Rigidity gain can be observed in sand aging but is usually accompanied by minute densification.This phenomenon is inconsistent with the conventional diagram of rigidity/jamming transition for granules and therefore too enigmatic to be utilized in the field by engineers. Therefore, this study aims to reveal the mechanism of rigidity gain and reconcile the inconsistency in sand aging. The aging processes of two sand packings with the same mono-sized spheres but different initial densities were reproduced via discrete element method simulations. In the simulations, sudden increases in the solid fraction destroyed the similarity between the evolution processes of rigidity gain and densification, confirming the inadequacy of explaining this gain considering densification alone. The bond-orientational order remained almost unchanged, while the contact-force order generally increased over time with distinct drops, similar to the change in rigidity gain. This evolution pattern is attributed to the laws of thermodynamics, which require the Gibbs energy of the sand packing to decrease over time, and contact-force order reduction assists with this decrease. Simultaneously, this reduces the nonaffinity under shear and rigidity demolition, consequently dominating the rigidity gain mechanism in sand aging. Based on these findings, the conventional diagram of rigidity transition was modified to jointly consider the effects of the solid fraction and structural orders. The proposed diagram can depict how the sand packing rigidity is enhanced over time and can better guide the consideration of the sand aging effect in the field.

상업적 우정의 결정요인과 그 결과변수에 관한 연구

전성준(Chengjun Quan),이원정(Weonjeong Yi),박영훈(Younghoun Park),강기두(Gi-Du Kang) 대한경영학회 2021 大韓經營學會誌 Vol.34 No.1