Iterative Learning Control of Linear Distributed Parameter Systems.Frequency Domain Design and Analysis

Deqing Huang,Xuefang Li,Jian-Xin Xu,Chao Xu 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

This paper aims at iterative learning control (ILC) design and analysis for a class of linear distributed parameter systems (DPSs) that may be hyperbolic, parabolic, or elliptic, and include many important physical processes such as diffusion, vibration, heat conduction and wave propagation as special cases. Owing to the linear characteristic of systems, the system equations are first cast into a matrix form in the Laplace transform domain. Then, through determination of a fundamental matrix, the system transfer function is precisely evaluated in a closed form. The derived transfer function clearly demonstrates the input-output relationship of system, and thus facilitates the consequent ILC design and convergence analysis in the frequency domain. The proposed control design scheme is able to deal with parametric and non-parametric uncertainties and makes full use of the process repetition, while avoids any simplification or discretization for the 3D dynamics of distributed parameter systems in the time, space, and iteration domains. In the end, an illustrative example is presented to demonstrate the efficacy of the proposed ILC scheme.

Spatial Reuse in IEEE 802.11ax: Whether and How to Use in Practice

( Deqing Zhu ),( Shenji Luan ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.12

IEEE 802.11ax is a protocol being developed for high-density Wireless Local Area Networks (WLAN). Several algorithms have been proposed to improve the level of spatial reuse applied in IEEE 802.11ax. However, these algorithms are tentative and do not specify how to select the transmit power and carrier sense threshold in practice; It is unclear when and why the tuned parameters lead to better network performance. In this paper, we restricted the scale of transmit power tuning to prevent the case of backfire in which spatial reuse will result in transmission failure. If the restrictions cannot be satisfied, spatial reuse will be abandoned. This is why we named the proposed scheme as Arbitration based Spatial Reuse (ASR). We quantified the network performance after spatial reuse, and formulate a corresponding maximum problem whose solution is the optimal carrier sense threshold and transmit power. We verified our theoretical analysis by simulation and compared it with previous studies, and the results show that ASR improves the throughput up to 8.6% compared with 802.11ax. ASR can avoid failure of spatial reuse, while the spatial reuse failure rate of existing schemes can up to 36%. To use the ASR scheme in practice, we investigate the relation between the optimal carrier sense threshold and transmit power. Based on the relations got from ASR, the proposed Relation based Spatial Reuse (RSR) scheme can get a satisfactory performance by using only the interference perceived and the previously found relations.

Protective Effects of Aqueous Extract of Radix Isatidis on Lipopolysaccharide-Induced Sepsis in C57BL/6J Mice

Deqing Ruan,Wenjing Liu,Yanhong Shi,Menghui Tan,Li Yang,Zhengtao Wang,Yue Zhou,Rui Wang 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.1

Endotoxic shock exhibits a considerably high mortality risk. It is defined as a systemic inflammatory response syndrome caused by a microbial infection. Radix Isatidis has anti-inflammatory, antiviral, and antipyretic effects and is used worldwide. This study investigated the antiendotoxin sepsis effects of an aqueous R. Isatidis extract (RIE) and explored the possible pharmacological molecular mechanisms. Male C57BL/6J mice were intravenously injected with 15 mg/kg lipopolysaccharide (LPS) to induce endotoxic shock. The results demonstrated that the survival rate of mice pretreated with RIE increased, and LPS-induced liver and lung damage were reduced by inhibiting inflammation. For elucidating detailed molecular mechanisms, we focused on LPS-induced transcription factors: nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3). Our results demonstrated that the protective effects of RIE were strongly dependent on IRF3-induced interferon-β, not on NF-κB-induced tumor necrosis factor-α and interleukin-1β. In addition, RIE suppressed the phosphorylation of IRF3, not NF-κB. In conclusion, this study revealed the antiendotoxic properties of RIE on LPS-induced sepsis and provided mechanistic evidence for the beneficial effects of RIE.

DISTRIBUTION OF ROOTS OF CUBIC EQUATIONS

Deqing Huang,Yilei Tang,Weinian Zhang 한국수학교육학회 2010 純粹 및 應用數學 Vol.17 No.2

In this note the distribution of roots of cubic equations in contrast to 0is given, which is useful to discuss eigenvalues for qualitative properties of differential equations.

Damping and transformation behaviors of Ti50(Pd50−xCrx) shape memory alloys with x ranging from 4.0 to 5.0

Deqing Xue,Ruihao Yuan,Dezhen Xue,Yumei Zhou,Guojun Zhang,Xiangdong Ding,Jun Sun 한국물리학회 2018 Current Applied Physics Vol.18 No.7

The damping and transformation behaviors of Ti50(Pd50−xCrx) shape memory alloys with x ranging from 4.0 to 5.0 are systematically investigated. The damping capacity (Q−1) at the martensitic transformation is found to be inversely proportional to the square root of frequency, i.e., Q−1∝ω−0.5. A relaxation peak or shoulder is observed slightly below the martensitic transformation damping peak for compositions within the compositional crossover region (4.5 ⩽x⩽ 4.8). Furthermore, the damping capacity at the martensitic transformation is smaller within the compositional crossover region (4.5 ⩽x⩽ 4.8), compared with that of compositions at both sides (x = 4.0 and x = 5.0). These observations can be ascribed to the hysteretic motion of interfaces between different phases near the compositional crossover region.

Generic Adaptive Sliding Mode Control for a Quadrotor UAV System Subject to Severe Parametric Uncertainties and Fully Unknown External Disturbance

Tianpeng Huang,Deqing Huang,Zhikai Wang,Xi Dai,Awais Shah 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.2

This paper aims to provide a generic robust controller that is able to manipulate all kinds of quadrotor unmanned aerial vehicle (UAV) systems automatically or adaptively in the presence of severe parametric uncertainties and fully unknown external disturbance. The dynamic model of the quadrotor is first obtained using Newton-Euler equations. Then, considering the underactuated and the strongly coupled characteristics of the quadrotor system, a nonlinear adaptive sliding mode control (ASMC) scheme is proposed. Meanwhile, additional adaptive laws are designed to estimate all the parameters of the quadrotor system, which in principle are difficult to be measured directly and accurately. Furthermore, to guarantee the asymptotic stability of the closed-loop system, the upper bound of the fully unknown external disturbance is estimated and adopted as the switching gain of the ASMC. Finally, simulations and experiments are carried out to illustrate the effectiveness and robustness of the proposed control scheme, where the superiority to linear quadratic control (LQR) and active disturbance rejection control (ADRC) has been demonstrated clearly.

Guaranteed Cost Optimal Control of High-speed Train with Time-delay in Cruise Phase

Xiangjin Tian,Deqing Huang,Na Qin,Zifeng Gong,Qingyuan Wang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.9

In this paper, a novel guaranteed cost control scheme that takes into account state time-delay and parametric uncertainties is proposed for high-speed train (HST) optimal operation control. First, a linear dynamic model of HST is built, where the basic and additional resistances, in-train force, train effort as well as state time-delay are addressed explicitly. Second, an operation criterion considering the velocity tracking, operation safety and running cost is established. Third, a guaranteed cost controller is then designed to realize the optimal control with tradeoff among the multiple objectives. To the best knowledge of the authors, it is the first time to address the velocity tracking, the operation safety and the running cost simultaneously while considering both state time-delay and parametric uncertainties, which corresponds to a more practical scenario in high-speed train control. At last, simulation is carried out to validate the effectiveness of the proposed control scheme under different delay degrees.

Impact resistance performance and optimal design of a sandwich beam with a negative stiffness core

Chenhui Ren,Deqing Yang,Qing Li 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7

Numerical analyses were carried out to investigate the response of a sandwich beam with a negative stiffness (NS) core under quasistatic compression and low-velocity impact at the center. By varying the thicknesses of face sheets and interlayers and the lengths of segments, a parametric study on the impact resistance of the sandwich beam is conducted. The maximal deflection of the top face sheet and the strain energy stored in the NS beam were recorded at the moment when the impactor’s velocity decreased to zero. Based on the impact simulation, a multi-objective optimization problem on the beam configuration was set up to find out the most efficient antideformation design at the impact velocity of 2500 mm/s. To solve the problem with the surrogate model method, an optimal Latin hypercube sampling (OLHS) technique and a two-phase differential evolution (ToPDE) algorithm were utilized to generate calculation points in the design space, respectively. Then different surrogate models including the RSM model, the Kriging model and the RBF model, were compared to give the best approximation of the original problem. In the end, the genetic algorithm (GA) dealing with discrete optimization problems was employed to obtain the optimum solutions. Results indicate that different parts of the NS beam dominate the resistance to deformation under different levels of impact intensity. The largest portion of the strain energy is stored in the four curved plates. In the obtained optimization solution, the longest segment is near the two ends and the flat plates near the top are thicker, which is instructive to the beam design on improving impact resistance.

Adaptive Nonsingular Terminal Sliding Mode Tracking Control for High-speed Trains With Input Constraints and Parametric Uncertainties

Zikang Li,Deqing Huang,Liangcheng Cai 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

In this paper, a finite-time tracking control strategy for high-speed trains (HSTs) subjected to inputconstraints and parameter uncertainties is proposed based on adaptive nonsingular terminal sliding mode control(ANTSMC), which achieves the fast and precise displacement-speed trajectory tracking and energy saving results. The dynamic model of HST is established with the basic, additional, and external disturbances firstly. To handle input constraints, a smooth hyperbolic function is designed to approximate saturation function, which guarantees thatthe control signal does not exceed traction/braking characteristics and ensures safe operation. Then, an adaptivemechanism is used to estimate the upper bounder of the lumped uncertainty and controller’s parameters. Subsequently, the proposed ANTSMC methodology not only assures the finite-time convergence of position and velocitytracking errors, but also effectively compensates parameter uncertainties of the proposed model. Finally, numerical simulations indicate that the proposed method spends the less traction energy in obtaining the better trackingperformance of HST.

Four active monomers from Moutan Cortex exert inhibitory effects against oxidative stress by activating Nrf2/Keap1 signaling pathway

Baoshun Zhang,Deqing Yu,Nanxuan Luo,Changqing Yang,Yurong Zhu 대한생리학회-대한약리학회 2020 The Korean Journal of Physiology & Pharmacology Vol.24 No.5

Paeonol, quercetin, β-sitosterol, and gallic acid extracted from Moutan Cortex had been reported to possess anti-oxidative, anti-inflammatory, and antitumor activities. This work aimed to illustrate the potential anti-oxidative mechanism of monomers in human liver hepatocellular carcinoma (HepG2) cells-induced by hydrogen peroxide (H₂O₂) and to evaluate whether the hepatoprotective effect of monomers was independence or synergy in mice stimulated by carbon tetrachloride (CCl₄). Monomers protected against oxidative stress in HepG2 cells in a doseresponse manner by inhibiting the generation of reactive oxygen species, increasing total antioxidant capacity, catalase and superoxide dismutase (SOD) activities, and activating the antioxidative pathway of nuclear factor E2-related factor 2/Kelchlike ECH-associated protein 1 (Nrf2/Keap1) signaling pathway. We found that the in vitro antioxidant capacities of paeonol and quercetin were better than those of -sitosterol and gallic acid. Furthermore, paeonol apparently diminished the levels of alanine transaminase and aspartate aminotransferase, augmented the contents of glutathione and SOD, promoted the expressions of Nrf2 and heme oxygenase-1 proteins in mice stimulated by CCl₄. In HepG2 cells, paeonol, quercetin, β-sitosterol, and gallic acid play a defensive role against H₂O₂-induced oxidative stress through activating Nrf2/Keap1 pathway, indicating that these monomers have anti-oxidative properties. Totally, paeonol and quercetin exerted anti-oxidative and hepatoprotective effects, which is independent rather than synergy.