Near-Optimal Tracking Control for Discrete-time Systems with Delayed Input

Gong-You Tang,Shi-Yuan Han,Cheng-Ming Zhang 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.6

This paper considers the near-optimal tracking control problem for discrete-time systems with delayed input. Using a variable transformation, the system with delayed input is transformed into a non-delayed system, and the quadratic performance index of the optimal tracking control is transformed into a relevant format. The optimal tracking control law is constructed by the solution of a Riccati matrix equation and a Stein matrix equation. A reduced-order observer is constructed to solve the physically realizable problem of the feedforward compensator and a near-optimal tracking control is obtained. Simulation results demonstrate the effectiveness of the optimal tracking control law.

Improvement on the Laminated Busbar of NPC Three-Level Inverters based on a Supersymmetric Mirror Circulation 3D Cubical Thermal Model

Feng-You He,Shi-Zhou Xu,Cheng-Fei Geng 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Laminated busbars with a low stray inductance are widely used in NPC three-level inverters, even though some of them have poor performances in heat equilibrium and overvoltage suppression. Therefore, a theoretical method is in need to establish an accurate mathematical model of laminated busbars and to calculate the impedance and stray inductance of each commutation loop to improve the heat equilibrium and overvoltage suppression performance. Firstly, an equivalent circuit of a NPC three-level inverter laminated busbar was built with an analysis of the commutation processes. Secondly, on the basis of a 3D (three dimensional) cubical thermal model and mirror circulation theory, a supersymmetric mirror circulation 3D cubical thermal model was built. Based on this, the laminated busbar was decomposed in 3D space to calculate the equivalent resistance and stray inductance in each commutation loop. Finally, the model and analysis results were put into a busbar design, simulation and experiments, whose results demonstrate the accuracy and feasibility of the proposed method.

Improvement on the Laminated Busbar of NPC Three-Level Inverters based on a Supersymmetric Mirror Circulation 3D Cubical Thermal Model

He, Feng-You,Xu, Shi-Zhou,Geng, Cheng-Fei The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Laminated busbars with a low stray inductance are widely used in NPC three-level inverters, even though some of them have poor performances in heat equilibrium and overvoltage suppression. Therefore, a theoretical method is in need to establish an accurate mathematical model of laminated busbars and to calculate the impedance and stray inductance of each commutation loop to improve the heat equilibrium and overvoltage suppression performance. Firstly, an equivalent circuit of a NPC three-level inverter laminated busbar was built with an analysis of the commutation processes. Secondly, on the basis of a 3D (three dimensional) cubical thermal model and mirror circulation theory, a supersymmetric mirror circulation 3D cubical thermal model was built. Based on this, the laminated busbar was decomposed in 3D space to calculate the equivalent resistance and stray inductance in each commutation loop. Finally, the model and analysis results were put into a busbar design, simulation and experiments, whose results demonstrate the accuracy and feasibility of the proposed method.

ABO Blood Group, Epstein-Barr virus Infection and Prognosis of Patients with Non-metastatic Nasopharyngeal Carcinoma

Zhang, Ya-Xiong,Kang, Shi-Yang,Chen, Gang,Fang, Wen-Feng,Wu, Xuan,You, Hua-Jing,He, Da-Cheng,Cao, Ya-Lin,Liang, Wen-Hua,Zhang, Li Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

Background: A prior study showed blood type A/AB to be associated with an increased risk of nasopharyngeal carcinoma (NPC) compared to subjects with blood type O. However, the relationship between ABO blood groups and prognosis of NPC patients is still questionable. In addition, whether Epstein-Barr virus (EBV) infection is associated with prognosis of NPC patients with different ABO blood groups is unclear. Materials and Methods: We conducted univariate and multivariable Cox regression analyses based on a consecutive cohort of 1,601 patients to investigate the above issues. Results: There was no significant difference in overall survival (OS) between different ABO blood groups (p=0.629), neither between A vs. non-A blood groups (p=0.895) nor AB vs. non-AB blood group (p=0.309) in univariate analyses and after adjusting for other factors. Interaction tests revealed that high immunoglobulin A against Epstein-Barr virus viral capsid antigen (VcA-IgA) level was associated with a favorable prognosis in male patients with UICC stage II disease who had an A blood type (p=0.008), compared with those with non-A blood type. In addition, male patients with an A blood group with a high blood lymphocyte level showeda tendency towards better survival in UICC stage III (p=0.096). Conclusions: ABO blood group status is not associated with the prognosis of patients with NPC. Additionally, blood group A male NPC patients with high VcA-IgA level or high blood lymphocyte counts might be correlated with a favorable prognosis in UICC stage II or III, respectively.

THEORETICAL AND EXPERIMENTAL STUDY ON FLOW CHARACTERISTICS OF A DIAPHRAGM PUMP FOR UREA-SCR SYSTEMS

Shu Dong Yang,You Cheng Shi,Xi Wei Pan,Yin Shui Liu 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.4

Urea selective catalytic reduction (SCR) is the primary technology used to reduce the nitrogen oxides (NOx) of diesel engine exhaust. To meet the requirements of an SCR system, a novel type of miniature diaphragm pump was designed. Based on the theory of large deflection of annular plates, the equilibrium equations of a diaphragm with a rigid inclusion were established, and the equations were solved by the nondimensional method and the finite difference method. Theoretical and approximated flow model for this pump were proposed. A theoretical relationship between back pressure, rigid inclusion size and volumetric efficiencies were calculated. To verify the validity of theoretical model, a prototype pump was fabricated and tested. Experimental results demonstrated that the flow is proportional to the pump speed. The deviation between theoretical, approximated flow and experimental flow was less than 4 % and 9.4 %, respectively. The difference between theoretical and experimental volumetric efficiency was varied from 2.7 % to 6.1 % when back pressure changed from 0 to 0.9 MPa. The volumetric efficiency was growing with the increasing of the rigid inclusion size. The pressures in the working chamber showed almost the same overall trends between the theoretical results and experimental values. The experimental results show that the proposed theoretical model is effective.

MicroRNA-206 Reduces Osteosarcoma Cell Malignancy In Vitro by Targeting the PAX3-MET Axis

Qian-Rong Deng,Fang-Biao Zhan,Xian-Wei Zhang,Shi-Long Feng,Jun Cheng,You Zhang,Bo Li,Li-Zhong Xie 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.2

Purpose: This study was undertaken to explore how miR-206 represses osteosarcoma (OS) development. Materials and Methods: Expression levels of miR-206, PAX3, and MET mRNA were explored in paired OS and adjacent tissuespecimens. A patient-derived OS cell line was established. miR-206 overexpression and knockdown were achieved by lentiviraltransduction. PAX3 and MET overexpression were achieved by plasmid transfection. Treatment with hepatocyte growth factor(HGF) was utilized to activate c-Met receptor. Associations between miR-206 and PAX3 or MET mRNA in OS cells were verifiedby AGO2-RNA immunoprecipitation assay and miRNA pulldown assay. OS cell malignancy was evaluated in vitro by cell proliferation,metastasis, and apoptosis assays. PAX3 and MET gene expression in OS cells was assayed by RT-qPCR and Western blot. Activation of PI3K-AKT and MAPK-ERK in OS cells were assayed by evaluating Akt1 Ser473 phosphorylation and total threoninephosphorylation of Erk1/2, respectively. Results: Expression levels of miR-206 were significantly decreased in OS tissue specimens, compared to adjacent counterparts,and were inversely correlated with expression of PAX3 and MET mRNA. miR-206 directly interacted with PAX3 and MET mRNAin OS cells. miR-206 overexpression significantly reduced PAX3 and MET gene expression in OS cells in vitro, resulting in significantdecreases in Akt1 and Erk1/2 activation, cell proliferation, and metastasis, as well as increases in cell apoptosis, while miR-206 knockdown showed the opposite effects. The effects of miR-206 overexpression on OS cells were reversed by PAX3 or METoverexpression, but only partially attenuated by HGF treatment. Conclusion: miR-206 reduces OS cell malignancy in vitro by targeting PAX3 and MET gene expression.