Adaptive Consensus Tracking of High-order Nonlinear Multi-agent Systems with Directed Communication Graphs

Junjie Fu,Jinzhi Wang 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.5

This paper studies the adaptive consensus tracking problem for multi-agent systems modeled as high-order integrators with uncertain nonlinear dynamics under directed communication graphs. By parameterizing the unknown dynamics of the agents and the unknown input of the leader, two de-centralized tracking control laws are designed using the state information and only the output informa-tion, respectively. With state information, globally uniformly ultimately bounded consensus tracking with arbitrarily small tracking errors can be achieved and when only output information is available, based on high-gain observers, semi-global result can be obtained. Numerical examples are provided to illustrate the effectiveness of the controllers.

Metalorganic Chemical Vapor Deposition of ZnO Films on Si (111) Substrates Using 3C-SiC Buffer Layers

Zhu Junjie,Lee InHwan,Ran Yao,Zhuxi Fu 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.3

Epitaxial ZnO films were prepared on Si (111) substrates using epitaxial 3C-SiC buffer layers. In particular, we tried different epitaxial 3C-SiC buffer layers to grow high quality ZnO films on silicon substrates by metal-organic chemical vapor deposition. The relationship between the quality of ZnO epitaxial layers and that of the SiC buffer layers was investigated. The epitaxial ZnO films were obviously improved by improving the SiC buffer layers. When the quality of the SiC buffer layers was good enough, the effect became less obvious.

Metallorganic Chemical Vapor Deposition of ZnO Films on Carbonized Si(111) and Si(100) Substrates

Zhu, Junjie,Yao, Ran,Fu, Zhuxi,Lee, In-Hwan The Electrochemical Society 2006 Journal of the Electrochemical Society Vol.153 No.9

Investigation on the Temperature Characteristics of Water Inner-Cooled Stator Coil of HTS Motor

Dong Qi,Zhao Junjie,Zhou Yong,Fu Xiaoli 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.6

This study investigates the temperature characteristics of water inner-cooled stator coil based on Litz wire for high temperature superconducting (HTS) motor. Rich experience in transposed Litz bundle windings is accumulated by manufacturing scaled-down water inner-cooled coil prototypes for high-capacity HTS motors. On this basis, the temperature rise test and calculation simulation are carried out. The maximum relative error between the two results is only 5.13%, which verified the rationality of the numerical temperature field calculation method. Subsequently, the effects of pipe blockage and epoxy thermal conductivity changes on the coil temperature are further explored. Thus, a relatively complete method for evaluating the temperature characteristics of water inner-cooled windings is formed, which can greatly help guide the design and manufacture of future high-capacity HTS motors.

Connectivity map identifies luteolin as a treatment option of ischemic stroke by inhibiting MMP9 and activation of the PI3K/ Akt signaling pathway

Shijian Luo,Huiqing Li,Zhihuai Mo,Junjie Lei,Lingjuan Zhu,Yanxia Huang,Ruying Fu,Chunyi Li,Yihuan Huang,Kejia Liu,Wenli Chen,Lei Zhang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

This study aimed to explore potential new drugs in the treatment of ischemic stroke by Connectivity Map (CMap) and to determine the role of luteolin on ischemic stroke according to its effects on matrix metalloproteinase-9 (MMP9) and PI3K/Akt signaling pathway. Based on published gene expression data, differentially expressed genes were obtained by microarray analysis. Potential compounds for ischemic stroke therapy were obtained by CMap analysis. Cytoscape and gene set enrichment analysis (GSEA) were used to discover signaling pathways connected to ischemic stroke. Cell apoptosis and viability were, respectively, evaluated by flow cytometry and an MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide) assay. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis were used to test the expression of MMP9 and the PI3K/Akt signaling pathway-related proteins in human brain microvascular endothelial cells (HBMECs) and tissues. Additionally, the infarct volume after middle cerebral artery occlusion (MCAO) was determined by a TTC (2,3,5-triphenyltetrazolium chloride) assay. The microarray and CMap analyses identified luteolin as a promising compound for future therapies for ischemic stroke. Cytoscape and GSEA showed that the PI3K/Akt signaling pathway was crucial in ischemic stroke. Cell experiments revealed that luteolin enhanced cell viability and downregulated apoptosis via inhibiting MMP9 and activating the PI3K/Akt signaling pathway. Experiments performed in vivo also demonstrated that luteolin reduced the infarct volume. These results suggest that luteolin has potential in the treatment of ischemic stroke through inhibiting MMP9 and activating PI3K/ Akt signaling pathway.

Nonlinear Optimization for Geometric Parameters of Reinforced Concrete Coupled Structural Walls

Yuntian Wu,Bin Wang,Yeongbin Yang,Junjie Fu 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.10

The coupling ratio (CR) has been widely used to quantitatively reflect the degree of coupling action between the component walls and link beams of a coupled wall. However, the CR index is very difficult to evaluate at early design stages. In order to develop alternative design parameters that can be easily utilized and ensure the dual lateral force resisting mechanism of coupled walls, nine prototype coupled walls were designed considering various aspect ratios of wall pier (αw) and span-to-depth ratios of coupling beams (αb). The incremental dynamic analyses on the seismic fragility was conducted to examine the influences of αw and αb on the fragility characteristics and the margin capacities corresponding to different performance limit states. The double-factorial quadratic response surface method was used to further reveal the interactive impact of αw and αb on the overall behavior of coupled walls. Then the combinations of αw and αb that can produce the optimal values of response variables were obtained. The curve-fitting technique was used to find the relationship between optimal αb and αw. It is indicated that αb and αw can effectively serve as the alternative parameters to CR and ensure optimal overall structural performance of RC coupled walls.

Therapeutic inhibition of SGK1 suppresses colorectal cancer

Xuchun Liang,Chunling Lan,Guanming Jiao,Wencheng Fu,Xuesha Long,Yu An,Kejin Wang,Jinzhe Zhou,Ting Chen,Yongqin Li,Jiahong Xu,Qi Huang,Bin Xu,Junjie Xiao 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Colorectal cancer (CRC) is one of the leading causes of death worldwide. Thus, the development of new therapeutic targets for CRC treatment is urgently needed. SGK1 is involved in various cellular activities, and its dysregulation can result in multiple cancers. However, little is known about its roles and associated molecular mechanisms in CRC. In present study, we found that SGK1 was highly expressed in tumor tissues compared with peri-tumor samples from CRC patients. In vitro experiments revealed that SGK1 overexpression promoted colonic tumor cell proliferation and migration and inhibited cell apoptosis induced by 5-fluorouracil (5-FU), while SGK1 shRNA and inhibitors showed the inverse effects. Using CRC xenograft mice models, we demonstrated that knockdown or therapeutic inhibition of SGK1 repressed tumor cell proliferation and tumor growth. Moreover, SGK1 inhibitors increased p27 expression and promoted p27 nuclear accumulation in colorectal cancer cells, and p27 siRNAs could attenuate the repression of CRC cell proliferation induced by SGK1 inhibitors. Collectively, SGK1 promotes colorectal cancer development via regulation

Identification and Expression Patterns of fvexpl1, an Expansin-Like Protein-Encoding Gene, Suggest an Auxiliary Role in the Stipe Morphogenesis of Flammulina velutipes

( Qianhui Huang ),( Xing Han ),( Irum Mukhtar ),( Lingling Gao ),( Rongmei Huang ),( Liping Fu ),( Junjie Yan ),( Yongxin Tao ),( Bingzhi Chen ),( Baogui Xie ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.4

Expansins are cell wall proteins that mediate cell wall loosening and promote specific tissue and organ morphogenesis in plants and in some microorganisms. Unlike plant expansins, the biological functions of fungal expansin-like proteins have rarely been discussed. In the present study, an expansin-like protein-encoding fvexpl1 gene, was identified from Flammulina velutipes by using local BLAST. It consisted of five exons with a total length of 822 bp. The deduced protein FVEXPL1 contained 274 amino acids with a predicted molecular mass and isoelectric point of 28,589 Da and pH 4.93, respectively. The first 19 amino acids from the N terminal are the signal peptide. Phylogenetic analysis and multiple protein alignment indicated FVEXPL1 was an expansin-like protein. The expression level of fvexpl1 gene in the stipe was significantly higher than that in the mycelia, primordia, and cap. However, the expression level of fvexpl1 gene was significantly higher in the fast elongation region of the stipe as compared with the slow elongation region. Expression analysis indicated that fvexpl1 gene might have an auxiliary role in the stipe morphogenesis of F. velutipes.

Research on the vibration characteristics and performance optimization of the rotor-shaft system of an unbalanced permanent magnet synchronous motor

Dongwen Wang,Wei Yang,Jiafeng Yang,Kongming Jiang,Junjie Zhang,Yang Fu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.9

Research on the vibration characteristics of the permanent magnet synchronous motor (PMSM) is hindered by the harmonic characteristics of the unbalanced magnetic pull force when air-gap eccentricity is neglected. Thus, the effects of both air-gap eccentricity and mass eccentricity on the rotor vibration have not yet been fully elucidated. To address this, a unified expression for the unbalanced magnetic pull force of the motor was derived under various pole pairs and air-gap eccentricities. The distribution of the radial electromagnetic force under different eccentricities is revealed. An electromagnetic simulation model of the fan motor was established for three eccentric cases and the effect of the unbalanced magnetic pull distribution and harmonic frequency characteristics on the rotor were analyzed. Furthermore, the influence of the gyroscopic effects on the modal frequency of the rotor structure was studied. The harmonic response of the rotor shaft system was first established using multi-physical field coupling, then the vibration amplitude-frequency laws of the rotor-shaft system under the influence of air-gap eccentricity and mass eccentricity were investigated. To reduce the vibration of the unbalanced PMSM rotor-shaft system, a multi-objective optimization was performed using the genetic algorithm in ANSYS Workbench. Research on the vibration characteristics of the permanent magnet synchronous motor (PMSM) is hindered by the harmonic characteristics of the unbalanced magnetic pull force when air-gap eccentricity is neglected. Thus, the effects of both air-gap eccentricity and mass eccentricity on the rotor vibration have not yet been fully elucidated. To address this, a unified expression for the unbalanced magnetic pull force of the motor was derived under various pole pairs and air-gap eccentricities. The distribution of the radial electromagnetic force under different eccentricities is revealed. An electromagnetic simulation model of the fan motor was established for three eccentric cases and the effect of the unbalanced magnetic pull distribution and harmonic frequency characteristics on the rotor were analyzed. Furthermore, the influence of the gyroscopic effects on the modal frequency of the rotor structure was studied. The harmonic response of the rotor shaft system was first established using multi-physical field coupling, then the vibration amplitude-frequency laws of the rotor-shaft system under the influence of air-gap eccentricity and mass eccentricity were investigated. To reduce the vibration of the unbalanced PMSM rotor-shaft system, a multi-objective optimization was performed using the genetic algorithm in ANSYS Workbench. The optimization results show that when the motor rotor core is shifted 2 mm in the positive X direction and the distance between the double-row bearing and rotor core is 7 mm, the vibration acceleration amplitude is reduced by 54.9 % compared with the original model.