Leader-Follower Consensus for a Class of Nonlinear Multi-Agent Systems

Xing-Hu Wang,Hai-Bo Ji 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.1

This paper deals with the leader-follower consensus problem for a class of nonlinear multi-agent sys-tems. All agents have identical nonlinear dynamics in the strict feedback form with Lipschitz growth condition. Both full state consensus protocol and dynamic output consensus protocol are provided. It is shown that under a connected undirected information communication topology, the proposed protocols can solve the leader-follower consensus problem. Two consensus protocol design procedures are presented and a numerical example is given to illustrate the proposed protocols.

Ginsenoside Rk1 ameliorates paracetamol-induced hepatotoxicity in mice through inhibition of inflammation, oxidative stress, nitrative stress and apoptosis

Hu, Jun-Nan,Xu, Xing-Yue,Li, Wei,Wang, Yi-Ming,Liu, Ying,Wang, Zi,Wang, Ying-Ping The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.1

Background: Frequent overdose of paracetamol (APAP) has become the major cause of acute liver injury. The present study was designed to evaluate the potential protective effects of ginsenoside Rk1 on APAP-induced hepatotoxicity and investigate the underlying mechanisms for the first time. Methods: Mice were treated with Rk1 (10 mg/kg or 20 mg/kg) by oral gavage once per d for 7 d. On the 7th d, allmice treated with 250mg/kg APAP exhibited severeliverinjury after 24 h, and hepatotoxicitywas assessed. Results: Our results showed that pretreatment with Rk1 significantly decreased the levels of serum alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor, and interleukin-$1{\beta}$ compared with the APAP group. Meanwhile, hepatic antioxidants, including superoxide dismutase and glutathione, were elevated compared with the APAP group. In contrast, a significant decrease in levels of the lipid peroxidation product malondialdehyde was observed in the ginsenoside Rk1-treated group compared with the APAP group. These effects were associated with a significant increase of cytochrome P450 E1 and 4-hydroxynonenal levels in liver tissues. Moreover, ginsenoside Rk1 supplementation suppressed activation of apoptotic pathways by increasing Bcl-2 and decreasing Bax protein expression levels, which was shown using western blotting analysis. Histopathological observation also revealed that ginsenoside Rk1 pretreatment significantly reversed APAP-induced necrosis and inflammatory infiltration in liver tissues. Biological indicators of nitrative stress, such as 3-nitrotyrosine, were also inhibited after pretreatment with Rk1 compared with the APAP group. Conclusion: The results clearly suggest that the underlying molecular mechanisms in the hepatoprotection of ginsenoside Rk1 in APAP-induced hepatotoxicity may be due to its antioxidation, antiapoptosis, anti-inflammation, and antinitrative effects.

Ginsenoside Rk1 ameliorates paracetamol-induced hepatotoxicity in mice through inhibition of inflammation, oxidative stress, nitrative stress and apoptosis

Jun-Nan Hu,Xing-Yue Xu,Wei Li,Yi-Ming Wang,Ying Liu,Zi Wang,Ying-Ping Wang 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.1

Background: Frequent overdose of paracetamol (APAP) has become the major cause of acute liver injury. The present study was designed to evaluate the potential protective effects of ginsenoside Rk1 on APAPinduced hepatotoxicity and investigate the underlying mechanisms for the first time. Methods: Micewere treated with Rk1 (10 mg/kg or 20 mg/kg) by oral gavage once per d for 7 d. On the 7th d, all mice treatedwith250mg/kgAPAPexhibitedsevere liver injuryafter24h, andhepatotoxicitywas assessed. Results: Our results showed that pretreatment with Rk1 significantly decreased the levels of serum alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor, and interleukin-1b compared with the APAPgroup.Meanwhile, hepatic antioxidants, including superoxide dismutase andglutathione,were elevated compared with the APAP group. In contrast, a significant decrease in levels of the lipid peroxidation product malondialdehyde was observed in the ginsenoside Rk1-treated group compared with the APAP group. These effectswere associatedwith a significant increase of cytochromeP450 E1 and 4-hydroxynonenal levels in liver tissues. Moreover, ginsenoside Rk1 supplementation suppressed activation of apoptotic pathways by increasing Bcl-2 and decreasing Bax protein expression levels, which was shown using western blotting analysis.Histopathological observation also revealed that ginsenoside Rk1 pretreatment significantly reversed APAP-induced necrosis and inflammatory infiltration in liver tissues. Biological indicators of nitrative stress, such as 3-nitrotyrosine, were also inhibited after pretreatment with Rk1 compared with the APAP group. Conclusion: The results clearly suggest that the underlying molecular mechanisms in the hepatoprotection of ginsenoside Rk1 in APAP-induced hepatotoxicity may be due to its antioxidation, antiapoptosis, anti-inflammation, and antinitrative effects.

Effect of Mixed Solvents on the Structure and Properties of PLLA/PDLA Electrospun Fibers

Xing Cao,Wei Wang,Jinjing Hu,Jiaming Wan,Li Cui 한국섬유공학회 2020 Fibers and polymers Vol.21 No.5

The electrospinning of poly(L-lactic acid)/poly(D-lactic acid) (PLLA/PDLA) microfiber membranes were carriedout with dichloromethane (DCM), DCM/ethanol, DCM/acetone, DCM/hexane as the spinning solvent. Scanning electronmicroscope observation showed that the electrospun fiber obtained using DCM/ethanol (L/D-DE) mixed solvent washomogeneous without visible bead, which was better than any others. Moreover, plenty of pores could be found on thesurface of the fibers obtained using the mixed solvents. The porous structure of fibers was significantly influenced by theethanol (non-solvent) content. When the DCM/ethanol was 50:10 (v/v), the fibers were uniform and had isolated pores. XRDand DSC results indicated that the exclusive stereocomplex poly(lactide acid) (sc-PLA) crystallites without anyhomocrystallites poly(lactide acid) (hc-PLA) did form in all types of fibers. The crystallinity of sc-PLA in the L/D-DE fiberwas higher than other samples due to the slowest evaporation rate. TGA test further indicated that the thermal stabilities ofPLLA/PDLA electrospun fibers were slightly better than the PLLA. Furthermore, L/D-DE had the excellent mechanicalproperties and underwent the course of ductile fracture. Possible mechanisms accounting for the morphologies and tensileproperties were also proposed in this study.

High-Pass-Filter-Based Virtual Impedance Control for LCL-filtered Inverters Under Weak Grid

Wang, Jiangfeng,Xing, Yan,Zhang, Li,Hu, Haibing,Yang, Tianyu,Lu, Daorong The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.6

Voltage feed-forward control (VFFC) is widely used in LCL-type grid-tied inverters due to its advantages in terms of disturbance rejection performance and fast dynamic response. However, VFFC may worsen the stability of inverters under weak grid conditions. It is revealed in this paper that a large phase-lag in the low-frequency range is introduced by VFFC, which reduces the phase margin significantly and leads to instability. To address this problem, a novel virtual-impedance-based control, where a phase-lead is introduced into the low-frequency area to compensate for the phase lag caused by VFFC, is proposed to improve system stability. The proposed control is realized with a high-pass filter, without high-order-derivative components. It features easy implementation and good noise immunity. A detailed design procedure for the virtual impedance control is presented. Both theoretical analysis and experimental results verify the effectiveness of the control proposed.

An Optimized Third Harmonic Injection Method for Three-Phase Cascaded H-Bridge Photovoltaic Inverter

Wang Mao,Xing Zhang,Tao Zhao,Yuhua Hu,Fusheng Wang,Zhiqiang Dai,Renxian Cao 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The uneven irradiation and temperature in photovoltaic (PV) modules of three-phase cascaded H-bridge (CHB) inverters will cause the unbalanced output power between solar panels, resulting in unbalanced grid current between three phases. In addition, since each phase can be regarded as a single-phase inverter, the second harmonic voltage pulsation of dc-side capacitors is a problem to be solved. To solve these two problems, a third harmonic injection optimization method on the basis of fundamental frequency zero sequence is proposed in this paper. The third harmonic with the same amplitude of fundamental modulated wave signal is injected into the modulated wave signal when the amplitude of synthesized wave signal is no greater than unity. Otherwise, the amplitude of third harmonic is decreased correspondingly to ensure the amplitude of synthesized wave signal being unity. With this method, the dc-side voltage pulsation is effectively restrained and the power balancing limit of CHB inverter is expanded. The feasibility and effectiveness of this method are verified by an experimental prototype of a three-phase seven-level CHB inverter.

Improvement of the Multiple Image Encryption Capacity Using QR Code as a Data Container

Xing Bai,Jianping Hu,Sheng Yuan,Jinchao Wang,Jing Wang,Xin Zhou 한국광학회 2020 Current Optics and Photonics Vol.4 No.4

An image encryption scheme based on the quick response (QR) code as a data container has aroused wide interest due to the lossless recovery of the decrypted image. In this paper, we apply this method to multi-image encryption. However, since the decrypted image is affected by crosstalk noise, the number of multi-image encryptions is severely limited. To solve this problem, we analyzed the performance of QR code as a data container, and processed the decrypted QR code using the proposed method, so that the number of multi-image encryptions is effectively increased. Finally, we implemented a large image (256 × 256) encryption and decryption.

Diversity and Active Mechanism of Fengycin-Type Cyclopeptides from Bacillus subtilis XF-1 Against Plasmodiophora brassicae

( Xing Yu Li ),( Zi Chao Mao ),( Yue Hu Wang ),( Yi Xing Wu ),( Yue Qiu He ),( Chun Lin Long ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.3

Bacillus subtilis XF-1, a strain with demonstrated ability to control clubroot disease caused by Plasmodiophora brassicae, was studied to elucidate its mechanism of antifungal activity against P. brassicae. Fengycin-type cyclopeptides (FTCPs), a well-known class of compounds with strong fungitoxic activity, were purified by acid precipitation, methanol extraction, and chromatographic separation. Eight homologs of fengycin, seven homologs of dehydroxyfengycin, and six unknown FTCPs were characterized with LC/ESI-MS, LC/ESI-MS/MS, and NMR. FTCPs (250μg/ml) were used to treat the resting spores of P. brassicae (107/ml) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be cleaved by the FTCPs of B. subtilis XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol.

High-Pass-Filter-Based Virtual Impedance Control for LCL-filtered Inverters Under Weak Grid

Jiangfeng Wang,Yan Xing,Li Zhang,Haibing Hu,Tianyu Yang,Daorong Lu 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.6

Voltage feed-forward control (VFFC) is widely used in LCL-type grid-tied inverters due to its advantages in terms of disturbance rejection performance and fast dynamic response. However, VFFC may worsen the stability of inverters under weak grid conditions. It is revealed in this paper that a large phase-lag in the low-frequency range is introduced by VFFC, which reduces the phase margin significantly and leads to instability. To address this problem, a novel virtual-impedance-based control, where a phase-lead is introduced into the low-frequency area to compensate for the phase lag caused by VFFC, is proposed to improve system stability. The proposed control is realized with a high-pass filter, without high-order-derivative components. It features easy implementation and good noise immunity. A detailed design procedure for the virtual impedance control is presented. Both theoretical analysis and experimental results verify the effectiveness of the control proposed.

Residual Load Sway Reduction Control in Double-pendulum Overhead Cranes Using Motion Trajectory Based on Adams-Matlab Joint Simulation

Jinxin Hu,Huimin Ouyang,Wenwei Huang,Ping Xing,Chunmin Yu,Guangming Zhang,Lei Mei,Xin Deng,Deming Wang 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

When the hook mass is greater than the load mass or the load has a distributed mass property, the load sway of the crane system can be considered as a double-pendulum. At this point, the crane system has two kinds of natural angular frequency which greatly increases the difficulty of the dynamic analysis and the controller design. To this end, the linear dynamics of a 2-D overhead crane with double-pendulum effect is derived based on a disturbance observer and is decoupled for controller design by modal analysis. Second, an S-shaped curve, which is widely used in the control fields, is applied to the linearized decoupling crane model. The trajectory parameters are obtained by solving the algebraic equation. Finally, the validity of the method is verified by simulation results.