Effects of high-temperature stress and heat shock on two root maggots, Bradysia odoriphaga and Bradysia difformis (Diptera: Sciaridae)

Guodong Zhu,Yin Luo,Ming Xue,Haipeng Zhao,NanNan Xia,Xinhui Wang 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

Bradysia odoriphaga and B. difformis (Diptera: Sciaridae) are devastating pests of vegetables, ornamentals andedible mushrooms. In Chinese chive fields, the two Bradysia species occur with similar regularities: outbreaks inspring and autumn, and population decreases in summer. Temperature may be an important factor restrictingtheir population abundance in summer. Here, we performed a life-table study under constant high temperaturesand assessed the tolerance of two Bradysia species to heat shock. Life parameters of the Bradysia species indicatedslow developmental rates, and low survival rates and fecundity, when the temperature was higher than 30 °C. At34 °C, individuals were unable to reach the adult stages from eggs. Moreover, temperatures above 36 °C showedlethal effects, decreasing their survival rates. The median lethal time (LT50) values of 4th instar B. odoriphagaand B. difformis larvae were 46.82 and 32.97 h, respectively, while the values at 38 °C were 2.12 and 1.51 h,respectively. The 4th instar larvae and pupae possessed higher thermotolerance levels than adults and eggs,indicating sensitivities to heat stress. Moreover, B. odoriphaga was more thermotolerant than B. difformis. Thus,weak thermotolerance levels may restrict their occurrences during the period of summer heat, and the differencein thermotolerance levels between the two species may be related to their regional distributions.

Modeling, Dynamic Analysis and Control Design of Full-Bridge LLC Resonant Converters with Sliding-Mode and PI Control Scheme

Kai Zheng,Guodong Zhang,Dongfang Zhou,Jianbing Li,Shaofeng Yin 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

In this paper, a sliding mode and proportional plus integral (SM-PI) control combined with self-sustained phase shift modulation (SSPSM) for LLC resonant converters is presented. The proposed control scheme improves the transient response while preserving good steady-state performance. An averaged large signal model of an LLC converter with the ZVS modulation technique is developed for the SM control design. The sliding surface is obtained based on the input-output linearization concept. A system identification method is adopted to obtain the transform function of the LLC resonant converter, which is used to design the PI control. In order to reduce the inherent chattering problem in the steady state, the combined SM-PI control strategy is derived with fuzzy control, where the SM control is responsive during the transient state while the PI control prevails in the steady state. The combination of SSPSM and the SM-PI control provides ZVS operation, robustness and a fast transient response against step load variations. Simulation and experimental results validate the theoretical analysis and the attractive features of the proposed scheme.

DISTRIBUTED FORMATION CONTROL OF HOMOGENEOUS VEHICLE PLATOON CONSIDERING VEHICLE DYNAMICS

Liwei Xu,Weichao Zhuang,Guodong Yin,Chentong Bian 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.6

Vehicle dynamics plays a significant role on the formation of a vehicle platoon, especially at high speed condition. This paper proposes a distributed platoon formation framework for homogeneous autonomous vehicles which takes the vehicle dynamics into consideration. The boundaries of vehicle stability are firstly calculated by considering both lateral dynamics and actuator saturation. By combining the stability boundaries with multi-objective flocking (MOF) algorithm, a distributed formation controller is designed, which can form the vehicle platoon with high cruising speed steadily and rapidly. In addition, a low-level tracking controller is proposed to constitute a hierarchical control architecture which can achieve stable and accurate formation of platoon. Simulation results show the proposed platoon formation controller achieves safe, stable and rapid platoon formation than the traditional MOF-based formation controller which does not consider the vehicle dynamics.

Modeling, Dynamic Analysis and Control Design of Full-Bridge LLC Resonant Converters with Sliding-Mode and PI Control Scheme

Zheng, Kai,Zhang, Guodong,Zhou, Dongfang,Li, Jianbing,Yin, Shaofeng The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

In this paper, a sliding mode and proportional plus integral (SM-PI) control combined with self-sustained phase shift modulation (SSPSM) for LLC resonant converters is presented. The proposed control scheme improves the transient response while preserving good steady-state performance. An averaged large signal model of an LLC converter with the ZVS modulation technique is developed for the SM control design. The sliding surface is obtained based on the input-output linearization concept. A system identification method is adopted to obtain the transform function of the LLC resonant converter, which is used to design the PI control. In order to reduce the inherent chattering problem in the steady state, the combined SM-PI control strategy is derived with fuzzy control, where the SM control is responsive during the transient state while the PI control prevails in the steady state. The combination of SSPSM and the SM-PI control provides ZVS operation, robustness and a fast transient response against step load variations. Simulation and experimental results validate the theoretical analysis and the attractive features of the proposed scheme.

Differences in the methanogen community between the nearshore and offshore sediments of the South Yellow Sea

Chen Ye,Zhen Yu,Wan Jili,Yin Xia,Li Siqi,Liu Jiayin,Zhang Guodong,Mi Tiezhu 한국미생물학회 2022 The journal of microbiology Vol.60 No.8

The differences in methanogen abundance and community composition were investigated between nearshore and offshore sediments in the South Yellow Sea (SYS). Shannon, Simpson, and Chao1 indices revealed a higher diversity of methanogens in the nearshore sediments than in the offshore sediments. The Mann–Whitney U test demonstrated that the relative abundance of Methanococcoides was significantly higher in the offshore sediments, while the relative abundances of Methanogenium, Methanosarcina, Methanosaeta, Methanolinea, and Methanomassiliicoccus were significantly higher in the nearshore sediments (P < 0.05). The abundance of the mcrA gene in the nearshore sediments was significantly higher than that in the offshore sediments. Furthermore, a similar vertical distribution of the methanogen and sulfatereducing bacteria (SRB) abundances was observed in the SYS sediments, implying there is potential cooperation between these two functional microbes in this environment. Finally, total organic carbon (TOC) was significantly correlated with methanogen community composition.

Extended state observer-based finite time position control of rotational shell magazine via higher order sliding mode technique

Dong Chen,Linfang Qian,Qiang Yin,Guodong Liu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.6

An adaptive higher order sliding mode controller based on a novel finite-time extended state observer is designed for rotational shell magazine position tracking control. The design of observer does not need to use the eigenvalue of a specific matrix and thus the observer design can be greatly simplified. Based on the observer, the controller does not rely on the bound of disturbance. The values of controller gains could be reduced and chattering will be restrained. Observation error and tracking error are both finite-time stable. The close-loop stability has been proven via Lyapunov theory. Simulation and experiment results show that compared with twisting controller and proportional-integral controller, the proposed scheme can reduce the overshoot, weaken the chattering and reach the steady state faster in the presence of time-varying disturbance, parameter uncertainties and measurement noise.

Novel Payload Parameter Sensitivity Analysis on Observation Accuracy of Lightweight Electric Vehicles

Jin Xianjian,Wang Zhaoran,Yang Junpeng,Xu Liwei,Yin Guodong 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.5

Lightweight electric vehicles (LEVs) possess great advantages in the viewpoint of fuel consumption, environment protection and traffic mobility. However, due to the drastic reduction of vehicle weights and body size, the effects of payload parameter variation in LEV control and estimation system become much more pronounced and have to be systematically analysed. This paper proposes a novel payload parameter sensitivity analysis to provide quantitative insight into the sensitivity of payload parameter on the LEV system responses and state estimation. The analysis-oriented LEV dynamic model considering payload parameter variations is developed. Then, the trajectory sensitivity index of the influential parameters is defined and derived with the perturbation approach, the median method is used to improve the calculation accuracy for the trajectory sensitivity of payload parameter. Finally, the extended Kalman filter is designed to show the effect and importance of the sensitive payload parameters on the observation accuracy, the payload parameter variations along with fundamental state estimation such as vehicle sideslip angle, longitudinal velocity and vehicle roll angle are analysed. Simulation results with Matlab/Simulink-Carsim® show that the proposed method can accurately describe the relationship between the vehicle payload parameters and system state estimation, which is helpful to design and evaluate LEV controller and observer performances.