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Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4
This paper addresses two interrelated problems concerning the tracking control of podded propulsion unmanned surface vehicle (USV), namely, the modeling of podded propulsion USV, and trajectory tracking controller design. Based on the force analysis, the separation model of podded propulsion USV is established. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network minimum parameter learning method, neural shunting model and auxiliary dynamic system without the exact information of hydrodynamic damping structure and the sea disturbances. Using Lyapunov stability analysis theory, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of podded propulsion USV is demonstrated; then, neural shunting model and neural network minimum parameter learning method are introduced to cope with the problem of "explosion of complexity" and uncertainty factors, respectively; third, auxiliary dynamic system is introduced into controller design to reduce the risk of actuator saturation. Taking into account the above practical problems is helpful to engineering implementation in the marine practice. Finally, numerical simulation has been given to demonstrate the effectiveness of the proposed scheme.
Effect of annealing atmosphere on volatility of Bi in SrBi2Ta2O9 thin films
Dong-Sheng Wang 한양대학교 세라믹연구소 2014 Journal of Ceramic Processing Research Vol.15 No.2
The changes of structure and chemical composition of SrBi2Ta2O9 (SBT) thin films, which were annealed at 500 o C in N2 and forming gas (5%H2 + 95%N2), were investigated. Cross sectional morphology of SBT film was observed by scanning electron microscopy. The chemical composition and state were determined by using X-ray photoelectron microscopy and Auger electron spectrometer, respectively. N2 played a different role in annealing processes from forming gas. In the case of forming gas annealing, Bi element was reduced and appeared on the surface of SBT film or inside Si substrate. In the case of N2 annealing, only slight inter-diffusion occurs at SBT/Pt interface and small amounts of Bi are seen at Pt electrode layer. It could be attributed to the high annealing temperature. Compared with films annealed in forming gas, SBT films annealed in N2 exhibit better microstructure quality.
Sheng, Xu-Dong,Chen, Hu,Wang, Hui,Ding, Zhi-Bin,Xu, Gang-Zhu,Zhang, Jun-Feng,Lu, Wen-Chao,Wu, Tao,Zhao, Ling Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2
Fibulin-5 has recently been considered as a potential tumor suppressor in human cancers. Several studies have shown that it is down-regulated in a variety of tumor types and inhibits tumor growth and metastasis. This study was aimed to investigate the clinical significance of fibulin-5 in glioma and its role in cell proliferation and invasion. We found that the expression of fibulin-5 in glioma tissues was significantly lower than those in normal brain (NB) tissues. Negative expression was significantly correlated with advanced clinical stage (grade III+IV). Furthermore, Fibulin-5 negative expression was correlated with a shorter overall survival of glioma patients. Multivariate Cox repression analysis indicated that fibulin-5 was an independent factor for predicting overall survival of glioma patients. Overexpression obviously inhibited cell proliferation in U251 and U87 cells. Furthermore, it significantly reduced the number of migrating and invading glioma cells. In conclusion, impaired expression of fibulin-5 is correlated with the advanced tumor stage in glioma. Otherwise, Fibulin-5 is an independent prognostic marker for predicting overall survival of glioma patients. Mechanistically, it may function as a tumor suppressor via inhibiting cell proliferation and invasion in gliomas.
Sperm-mediated Gene Transfer in the Chinese Honeybee, Apis cerana cerana (Hymenoptera: Apidae)
Dong-Sheng Guo,Liang-Xian Sun,Zhi-Jiang Zeng,Xian-Bing Xie 한국응용곤충학회 2007 Journal of Asia-Pacific Entomology Vol.10 No.4
Transgenic Apis cerana cerana were produced by sperm-mediated gene transfer (SMGT). In the experiment, the foreign DNA was linearized and introduced with sperm during the instrumental insemination of virgin queen. The descendants of the experimental colonies were analyzed. In the green fluorescent-positive offspring, green fluorescence was observed for 1- to 2-day-old larvae, the predicted fragment was isolated by means of PCR amplification of genomic DNA and the expression of transferred genes was confirmed at transcriptional level by reverse transcription-polymerase chain reaction. These results showed that the exogenous gene could be integrated in a fraction of the germ line cells of the queen Apis cerana cerana and transmitted to offspring by SMGT.
Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.6
This paper addresses two interrelated problems concerning the tracking control of pod propulsion unmanned surface vessel (USV), namely, the modeling of pod propulsion USV, and tracking controller design. First, based on MMG modeling theory, the model of pod propulsion USV is derived. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network approximation and adaptive method. Meanwhile, unlike some existing tracking methods for surface vessel whose control algorithms suffer from “explosion of complexity”, a novel neural shunting model is introduced to solve the problem. Using a Lyapunov functional, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of pod propulsion USV is proved; second, the neural shunting model is used to solve the problem of “explosion of complexity”, and this is a combination of knowledge in the field of biology and engineering; third, the developed controller is able to capture the uncertainties without the exact information of hydrodynamic damping structure and the sea disturbances. Numerical examples have been given to illustrate the performance and effectiveness of the proposed scheme.
A Time-Varying Lookahead Distance of ILOS Path Following for Unmanned Surface Vehicle
Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.5
This paper is concerned with the path following control for an unmanned surface vessel subject to unknown dynamics and external disturbance. Firstly, an integral Line-of-Sight navigation strategy based on a fuzzy strategy to optimize lookahead distance to achieve faster convergence speed is proposed. Then a novel adaptive course control law based on trajectory linearization control technology is proposed, which is combined with the integral Line-of-Sight navigation strategy to form a complete unmanned surface vessel path following strategy. From the author’s point of view, this is the fi rst time that trajectory linearization control technology has been applied to the path following scheme by controlling the course. At the same time, in order to improve the robustness of the path following system, the unknown dynamics, external disturbance, and error in the system are compensated by neural network minimum learning parameter method with less computational complexity and a robust term, respectively. Furthermore, hyperbolic tangent function, Nussbaum function, and neural shunting model are introduced into the design of control law to solve the potential input saturation problem. Finally, the numerical simulation experiments of straight line and curve path following are given to prove the feasibility and universality of the whole set of path following scheme.
Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.11
This paper addresses the formation tracking control problem of multiple underactuated unmanned surface vehicles. Considering many actual situations, a practical formation control scheme, which is performed by using a leader-follower approach, minimum learning parameter technique, adaptive technology and so on. Firstly, a virtual unmanned surface vehicle is designed according to the location information of the leader unmanned surface vehicle to estimate the leader’s speed information while reducing the communication bandwidth. Secondly, a formationcontrol law is designed to make the follower underactuated unmanned surface vehicles track the leader. Unknown dynamics and external disturbances are regarded as a whole and compensated by the minimum learning parameter technique instead of multi-layer neural network and the neural shunt model can handle multiple derivation problems of virtual control laws. Meanwhile, the robustness of the controlled system is improved through adaptive technology. Besides, an auxiliary design system is employed to constrain the output range of the control law. Finally, numerical simulations are implemented to prove the feasibility of the formation tracking control strategy.