RELATION BETWEEN NONLINEAR DECOUPLING CONTROL AND VECTOR CONTROL

Ruan Yi,Chen Boshi,Wang Fengyao 전력전자학회 1995 ICPE(ISPE)논문집 Vol.1995 No.10

An inverter fed induction motor system reprented in rotating coordinates can be separated into three linear single variable subsystems by means of nonlinear transformation of coorninates and nonlinear state feedback. The result show that nonlinear decoupling control are just the same of vector control system The conclusion that the vector control system is a class of realization of nonlinear decoupling control of the induction motor is then deduced.

Tailoring fabric geometry of plain-woven composites for simultaneously enhancing stiffness and thermal properties

Xiao-Yi Zhou,Neng-Wei Wang,Wen Xiong,Xin Ruan,Shao-Jin Zhang 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.4

This paper proposes a numerical optimization method to design the mesoscale architecture of textile composite for simultaneously enhancing mechanical and thermal properties, which compete with each other making it difficult to design intuitively. The base cell of the periodic warp and fill yarn system is served as the design space, and optimal fibre yarn geometries are found by solving the optimization problem through the proposed method. With the help of homogenization method, analytical formulae for the effective material properties as functions of the geometry parameters of plain-woven textile composites were derived, and they are used to form the inverse homogenization method to establish the design problem. These modules are then put together to form a multiobjective optimization problem, which is formulated in such a way that the optimal design depends on the weight factors predetermined by the user based on the stiffness and thermal terms in the objective function. Numerical examples illustrate that the developed method can achieve reasonable designs in terms of fibre yarn paths and geometries.

Aberrant Expression of HOXA5 and HOXA9 in AML

Zhao, Peng,Tan, Li,Ruan, Jian,Wei, Xiao-Ping,Zheng, Yi,Zheng, Li-Xia,Jiang, Wei-Qin,Fang, Wei-Jia Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.9

Background: Aberrant expression of HOX gene expression has been observed in cancer. The purpose of this study was to investigate the alteration of HOXA5 and HOXA9 expression and their clinical significance in acute meloid leukemia (AML). Materials and Methods: The expression of HOXA5 and HOXA9 genes of bone marrow samples from 75 newly diagnosed AML patients and 22 healthy controls for comparison were examined by Real-time quantitative PCR (RQ-PCR) assay. Statistical analysis was conducted to evaluate HOXA5 and HOXA9 expression as possible biomarkers for AML. Results: The results showed that the complete remission rate (52.6%) of the patients who highly expressed HOXA5 and HOXA9 was significantly lower than that (88.9%) in patients who lowly express the genes (P=0.015). Spearmann correlation coefficients indicated that the expression levels for HOXA5 and HOXA9 genes were highly interrelated (r=0.657, P<0.001). Meanwhile, we detected significant correlations between HOXA9 expression and age in this limited set of patients (P=0.009). Conclusions: The results suggest a prognostic impact of increased expression of HOXA5 and HOXA9 in AML patients.

An Improved Model Predictive Direct Torque Control for Induction Machine Drives

Song, Wenxiang,Le, Shengkang,Wu, Xiaoxin,Ruan, Yi The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.3

The conventional model predictive direct torque control (MPDTC) method uses all of the voltage vectors available from a two level voltage source inverter for the prediction of the stator flux and stator current, which leads to a heavy computational burden. This paper proposes an improved model predictive direct torque control method. The stator flux predictive controller is obtained from an analysis of the relationship between the stator flux and the torque, which can be used to calculate the desired voltage vector based on the stator flux and torque reference. Then this method only needs to evaluate three voltage vectors in the sector of the desired voltage vector. As a result, the computational burden of the conventional MPDTC is effectively reduced. The time delay introduced by the computational time causes the stator current to oscillate around its reference. It also increases the current and torque ripples. To address this problem, a delay compensation method is adopted in this paper. Furthermore, the switching frequency of the inverter is significantly reduced by introducing the constraint of the power semiconductor switching number to the cost function of the MPDTC. Both simulation and experimental results are presented to verify the validity and feasibility of the proposed method.

An Improved Model Predictive Direct Torque Control for Induction Machine Drives

Wenxiang Song,Shengkang Le,Xiaoxin Wu,Yi Ruan 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.3

The conventional model predictive direct torque control (MPDTC) method uses all of the voltage vectors available from a two level voltage source inverter for the prediction of the stator flux and stator current, which leads to a heavy computational burden. This paper proposes an improved model predictive direct torque control method. The stator flux predictive controller is obtained from an analysis of the relationship between the stator flux and the torque, which can be used to calculate the desired voltage vector based on the stator flux and torque reference. Then this method only needs to evaluate three voltage vectors in the sector of the desired voltage vector. As a result, the computational burden of the conventional MPDTC is effectively reduced. The time delay introduced by the computational time causes the stator current to oscillate around its reference. It also increases the current and torque ripples. To address this problem, a delay compensation method is adopted in this paper. Furthermore, the switching frequency of the inverter is significantly reduced by introducing the constraint of the power semiconductor switching number to the cost function of the MPDTC. Both simulation and experimental results are presented to verify the validity and feasibility of the proposed method.

Alkaloids from the bulbs of Lycoris longituba and their neuroprotective and acetylcholinesterase inhibitory activities

Yun-Yun Zhu,Xue Li,Heng-Yi Yu,Yu-Fang Xiong,Peng Zhang,Hui-Fang Pi,Han-Li Ruan 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.5

Three novel alkaloids (1–3), together withnineteen known ones (4–22), were isolated from the bulbsof Lycoris longituba. Their structures were elucidated onthe basis of extensive spectroscopic analyses, which belongto several Amaryllidaceae alkaloid skeletons. Amongthem, the harmane-type alkaloids (the new compound 1and the known compounds 5, 6 and 7) were found for thefirst time from Lycoris genus. The isolates were tested fortheir neuroprotective activities against CoCl2, H2O2 andAb25–35-induced SH-SY5Y cell injuries, and the majorityof them exhibited neuroprotective activities of differentdegrees. The acetylcholinesterase (AChE) inhibitoryactivities of the isolated alkaloids were also evaluated,while compounds 12, 14–20 and 22 exhibited extremelysignificant AChE inhibitory activities.

Four new compounds from the bulbs of Lycoris aurea with neuroprotective effects against CoCl2 and H2O2-induced SH-SY5Y cell injuries

An Jin,Xuelian Xiang,Yun-Yun Zhu,Heng-Yi Yu,Hui-Fang Pi,Peng Zhang,Han-Li Ruan 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.3

Three new alkaloids, 2a-hydroxy-6-O-n-butyloduline,O-n-butyllycorenine, (-)-N-(chloromethyl)lycoramine(1–3), and a new phenolic compound, ((7S)-7-(4-hydroxyphenyl)-7-hydroxypropyl)-20-methylbenzene-30,60-diol (14), along with ten known alkaloids (4–13), wereisolated from the bulbs of Lycoris aurea collected fromHuaihua County of Hunan Province, China. Their structureswere elucidated by spectroscopic methods includingHRESIMS, UV, IR, and NMR. All the isolated compoundswere tested for their neuroprotective effects against CoCl2and H2O2-induced SH-SY5Y cell death. Compounds 1–7and 10 exhibited significant neuroprotective effects againstCoCl2-induced SH-SY5Y cell injury, while compounds1–5, 7, 10 and 12 showed obvious neuroprotective effectsagainst H2O2-induced SH-SY5Y cell death.

Four new compounds from the bulbs of Lycoris aurea with neuroprotective effects against $CoCl_2$ and $H_2O_2$-induced SH-SY5Y cell injuries

Jin, An,Li, Xue,Zhu, Yun-Yun,Yu, Heng-Yi,Pi, Hui-Fang,Zhang, Peng,Ruan, Han-Li 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.3

Three new alkaloids, $2{\alpha}$-hydroxy-6-O-n-butyloduline, O-n-butyllycorenine, (-)-N-(chloromethyl)lycoramine (1-3), and a new phenolic compound, ((7S)-7-(4-hydroxyphenyl)-7-hydroxypropyl)-2'-methylbenzene-3',6'-diol (14), along with ten known alkaloids (4-13), were isolated from the bulbs of Lycoris aurea collected from Huaihua County of Hunan Province, China. Their structures were elucidated by spectroscopic methods including HRESIMS, UV, IR, and NMR. All the isolated compounds were tested for their neuroprotective effects against $CoCl_2$ and $H_2O_2$-induced SH-SY5Y cell death. Compounds 1-7 and 10 exhibited significant neuroprotective effects against $CoCl_2$-induced SH-SY5Y cell injury, while compounds 1-5, 7, 10 and 12 showed obvious neuroprotective effects against $H_2O_2$-induced SH-SY5Y cell death.

First Principles Study of Structural and Electronic Properties of Pentagonal and Hexagonal Noble Metal Nanowires

Zhijian Fu,Li-Jun Jia,JIHONG XIA,Hai-Bo Ruan,Ke Tang,Yong Pu,Zhao-Yi Zeng,Dian-Yong Tang,Bo Kong,Qi-Feng Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.6

The equilibrium structure and electronic properties of four ultrathin free-standing pentagonal and hexagonal noble metal nanowires, that is, copper nanowires (CuNWs), silver nanowires (AgNWs), gold nanowires (AuNWs) and platinum nanowires (PtNWs), have been studied comprehensively by adopting a first-principles simulation based on the density-functional theory. The staggered topologies are more stable than the eclipsed ones by analyzing the bonding energy. The staggered ones with a linear atom chain in the center of the pentagonal or hexagons topologies are the preferred structures for CuNWs and AgNWs, but the staggered ones without a linear atom chain in the center of the pentagon or hexagon are the preferred structures for AuNWs and PtNWs due to the increasing core–core repulsions. The calculated electronic band structures and density of states present that all the noble metal nanowires are metallic. The projected densities of states (PDOS) of dominant d-states and the charge density show that the narrower d-state moved to the Fermi energy and metallic bonding character for all the noble metal nanowires.

Possible Epithelial Ovarian Cancer Association with HPV18 or HPV33 Infection

Zhang, Pei-Pei,Zhou, Lei,Cao, Jia-Shi,Li, Yi-Ping,Zeng, Zhi,Sun, Ni,Shen, Li,Zhu, Hao-Yue,Ruan, Yang,Zha, Wen-Ting,Wang, Xin-Yu,Zhang, Ke-Qiang,Zhang, Ran Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.6

The present study was conducted to investigate the prevalence of HPV infection in epithelial ovarian cancer (EOC) in Hunan province. DNA samples were collected from paraffin embedded ovarian tissue from 322 patients with EOC, 99 with ovarian benign tumors and 199 normal persons. The polymerase chain reaction and direct sequencing were used to identify the HPV types in the samples. The relationship between the infection of human papillomavirus (HPV) and the epithelial ovarian carcinoma (EOC) was investigated combined with clinical data. The prevalence of HPV18 and HPV33 in EOC group and benign group was higher than in the normal group. HPV18 and HPV33 may play a role in the development of both EOC and ovarian benign tumor and may participate in the development of EOC with traditional risk factors, family history and abortion, possibly exerting synergistic effects.