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| 1 | Attitude tracking control for variable structure near space vehicles based on switched nonlinear systems显示文摘An adaptive robust attitude tracking control law based on switched nonlinear systems is presented for a variable structure near space vehicle (VSNSV) in the presence of uncertainties and disturbances. The adaptive fuzzy systems are employed for approximating unknown functions in the flight dynamic model and their parameters are updated online. To improve the flight robust performance, robust controllers with adaptive gains are designed to compensate for the approximation errors and thus they have less design conservation. Moreover, a systematic procedure is developed for the synthesis of adaptive fuzzy dynamic surface control (DSC) approach. According to the common Lyapunov function theory, it is proved that all signals of the closed-loop system are uniformly ultimately bounded by the continuous controller. The simulation results demonstrate the effectiveness and robustness of the proposed control scheme. | Wang Yufei Jiang Changsheng Wu Qingxian | 2013 | Chinese Journal of Aeronautics2013，26，1： | 21 |
| 2 | Epidemiological characteristics of thyroid nodules and risk factors for malignant nodules: a retrospective study from 6 304 surgical cases显示文摘 | Huan Qin Wang Kun Lou Fuchen Zhang Li Huang Qingxian Han Yunfeng Sun Hancheng Zhu Lei Lin Peng Song Jun Liu Fuqiang Wang Qian Hou Weikai | 2014 | Chinese Medical Journal2014，，12： | 20 |
| 3 | Progress and Prospects of Salt Lake Research in China显示文摘China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate(salt forming) have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits: the atlas(1:2500000) of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of 'Continental Potash Deposition Theory'; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti-floatation-cold crystallization method developed independently has improved the capacity of KCl production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K-sulfate production line, the biggest in the world, has been built in Lop Nor, and K-sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, i.e. brine preparation in winter-cooling-solarization-isolation-lithium deposition from salt gradient solar pond' the highest lithium production base at Zabuye Lake(4421 m), Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture(Salt land agriculture) has been established based on the mass growth of Dunaliella and other bacillus-algae and the occurrence of various halophytes in saltmarsh and salt saline-alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science 'Salinology'. | ZHENG Mianping ZHANG Yongsheng LIU Xifang NIE Zhen KONG Fanjing QI Wen Jia Qingxian PU Linzhong HOU Xianhua WANG Hailei ZHANG Zhen KONG Weigang LIN Yongjie | 2016 | Acta Geologica Sinica(English Edition)2016，90，4： | 15 |
| 4 | Combined obeticholic acid and apoptosis inhibitor treatment alleviates liver fibrosis显示文摘Obeticholic acid(OCA), the first FXR-targeting drug, has been claimed effective in the therapy of liver fibrosis. However, recent clinical trials indicated that OCA might not be effective against liver fibrosis, possibly due to the lower dosage to reduce the incidence of the side-effect of pruritus. Here we propose a combinatory therapeutic strategy of OCA and apoptosis inhibitor for combating against liver fibrosis. CCl4-injured mice, D-galactosamine/LPS(GalN/LPS)-treated mice and cycloheximide/TNFα(CHX/TNFα)-treated HepG2 cells were employed to assess the effects of OCA, or together with IDN-6556, an apoptosis inhibitor. OCA treatment significantly inhibited hepatic stellate cell(HSC)activation/proliferation and prevented fibrosis. Elevated bile acid(BA) levels and hepatocyte apoptosis triggered the activation and proliferation of HSCs. OCA treatment reduced BA levels but could not inhibit hepatocellular apoptosis. An enhanced anti-fibrotic effect was observed when OCA was co-administrated with IDN-6556. Our study demonstrated that OCA inhibits HSCs activation/proliferation partially by regulating BA homeostasis and thereby inhibiting activation of HSCs. The findings in this study suggest that combined use of apoptosis inhibitor and OCA at lower dosage represents a novel therapeutic strategy for liver fibrosis. | Jiyu Zhou Ningning Huang Yitong Guo Shuang Cui Chaoliang Ge Qingxian He Xiaojie Pan Guangji Wang Hong Wang Haiping Hao | 2019 | Acta Pharmaceutica Sinica B2019，9，3： | 13 |
| 5 | Robust adaptive backstepping control for a class of uncertain nonlinear systems based on disturbance observers显示文摘In this paper, a novel robust adaptive control scheme for a class of uncertain nonlinear systems is proposed using disturbance observer and backstepping method.Firstly, a disturbance observer is developed using radial basis function(RBF) neural network.The parameter updated law of the RBF neural network is given for monitoring subsystem disturbance well.The robust adaptive control scheme is then presented with backstepping method based on the designed disturbance observer.Semiglobal uniform ultimate boundedness(SGUUB) of all signals in the closed-loop uncertain nonlinear system is achieved.The closed-loop system stability analysis shows that semiglobal uniform boundedness of all signals is guaranteed by appropriately choosing design parameters.Finally, two examples are taken to illustrate the effectiveness of the proposed control scheme. | MEI Rong WU QingXian JIANG ChangSheng | 2010 | Science China(Information Sciences)2010，53，6： | 10 |
| 6 | Effects of extreme soil water stress on photosynthetic efficiency and water consumption characteristics of Tamarix chinensis in China's Yellow River Delta显示文摘Soil moisture is a major limiting factor for plant growth on shell ridge islands in the Yellow River Delta.However, it is difficult to carry out situ experiment to study dominant plant photosynthesis physiological on the shell ridge islands under extreme soil water stress. To evaluate the adaptability of plants to light and moisture variations under extreme soil moisture conditions present on these islands, we measured photosynthetic gas exchange process,chlorophyll fluorescence, and stem sap flow variables for3-year-old trees of Tamarix chinensis Lour, a restoration species on these islands, subjected to three types of soilwater levels: waterlogging stress(WS), alternating dry–wet(WD), and severe drought stress(SS) to inform decisions on its planting and management on shell ridge islands. Gas exchange, chlorophyll fluorescence, and stem sap flow in T.chinensis were then measured. Net photosynthetic rate(PN), transpiration rate(E), and water use efficiency(WUE)were similar under WS and alternating dry–wet conditions,but their mean E and WUEdiffered significantly(P \ 0.05).Under SS, the PN, E and WUEof T. chinensis leaves varied slightly, and mean PN, E and WUEwere all low. Apparent quantum efficiency(AQY), light compensation point(LCP),light saturation point(LSP), and maximum net photosynthetic rate(PNmax) of leaves were not significantly different(P [ 0.05) under WS and dry–wet conditions; however,under extreme drought stress, compared with the dry–wet conditions, LCPwas higher, LSPwas lower, and AQYand PNmaxwere both at the lowest level. Therefore, drought stress weakened light adaptability of leaves, and the efficiency of light transformation was poorer.(3) Maximum photochemical efficiency(Fv/Fm) and the actual photochemical efficiency(UPSII) were similar under waterlogged stress and dry–wet conditions, indicating a similar healthy photosynthetic apparatus and photosynthetic reaction center activity, respectively. Under SS, Fv/Fmwas 0.631, and the coefficient of non-photochemical quenching(NPQ) was0.814, which indicated that while the photosynthetic mechanism was damaged, the absorbed light energy was mainly dissipated in the form of heat, and the potential photosynthetic productivity was significantly reduced. The daily cumulants of sap flow of T. chinensis under dry–wet alternation and severe drought stress were 22.25 and63.97% higher, respectively, than under waterlogging stress. Daily changes in sap flow velocity for T. chinensis differed under the three soil water levels. Stem sap flow was weak at night under severe drought stress. Under dry–wet alternation, daytime average stem sap flow velocity was the highest, and night stem flow accounted for 10.26%of the day cumulants, while under waterlogged stress, the average nightly stem flow velocity was the highest,accounting for 31.82% of the day cumulants. These results provide important information for regional vegetation restoration and ecological reconstruction. | Yuan Gao Jiangbao Xia Yinping Chen Yanyun Zhao Qingxian Kong Ying Lang | 2017 | Journal of Forestry Research2017，28，3： | 9 |
| 7 | Adaptive recurrent-functional-link-network control for hypersonic vehicles with atmospheric disturbances显示文摘The controller design for a near-space hypersonic vehicle (NHV) is challenging due to its plant uncertainties and sensitivity to atmospheric disturbances such as gusts and turbulence. This paper first derives 12 states equations of NHVs subjected to variable wind field, and presents a novel recurrent neural network (RNN) control method for restraining atmospheric disturbances. The method devises a new B-spline recurrent functional link network (BRFLN) and combines it with the nonlinear generalized predictive control (NGPC) algorithm. Moreover, the proportional-derivative (PD) correction BRFLN is proposed to approximate atmo- spheric disturbances in flight. The weights of BRFLN are online tuned by the adaptive law based on Lyapunov stability theorem. Finally, simulation results show a satisfactory performance for the attitude tracking of the NHV in the mesosphere, and also illustrate the controller's robustness to wind turbulence. | DU YanLi WU QingXian JIANG ChangSheng XUE YaLi | 2011 | Science China(Information Sciences)2011，54，3： | 8 |
| 8 | A novel two-stage extended Kalman filter algorithm for reaction flywheels fault estimation显示文摘This paper investigates the problem of two-stage extended Kalman filter(TSEKF)-based fault estimation for reaction flywheels in satellite attitude control systems(ACSs). Firstly, based on the separate-bias principle, a satellite ACSs with actuator fault is transformed into an augmented nonlinear discrete stochastic model; then, a novel TSEKF is suggested such that it can simultaneously estimate satellite attitude information and actuator faults no matter they are additive or multiplicative; finally, the proposed approach is respectively applied to estimating bias faults and loss of effectiveness for reaction flywheels in satellite ACSs, and simulation results demonstrate the effectiveness of the proposed fault estimation approach. | Chen Xueqin Sun Rui Jiang Wancheng Jia Qingxian Zhang Jinxiu | 2016 | Chinese Journal of Aeronautics2016，29，2： | 7 |
| 9 | Robust adaptive compensation control for unmanned autonomous helicopter with input saturation and actuator faults显示文摘This paper studies a robust adaptive compensation Fault Tolerant Control(FTC)for the medium-scale Unmanned Autonomous Helicopter(UAH)in the presence of external disturbances,actuator faults and input saturation.To improve the disturbance rejection capacity of the UAH system in actuator healthy case,an adaptive control method is adopted to cope with the external disturbances and a nominal controller is proposed to stabilize the system.Meanwhile,compensation control inputs are designed to reduce the negative effects derived from actuator faults and input saturation.Based on the backstepping control and inner-outer loop control technologies,a robust adaptive FTC scheme is developed to guarantee the tracking errors convergence.Under the presented FTC controller,the uniform ultimate boundedness of all closed-loop signals is ensured via Lyapunov stability analysis.Simulation results demonstrate the effectiveness of the proposed control algorithm. | Kun YAN Mou CHEN Qingxian WU Ronggang ZHU | 2019 | Chinese Journal of Aeronautics2019，32，10： | 6 |
| 10 | Preparation and Characterization of Natural Bamboo Fiber显示文摘In this study,natural bamboo fiber was prepared combining chemical pretreatment with mechanical disc refining,opening,and carding.An orthogonal experiment was designed based on four factors and three levels;thereafter,the manufacturing process was optimized.The length,diameter,tensile strength,and elastic modulus of the bamboo fiber were determined,and the crystallinity and morphology of the fiber were analyzed using X-ray diffraction(XRD)and scanning electron microscopy(SEM).The results showed that the optimum parameters for the chemical pretreatment were a cooking temperature of 130℃,heating time of 2 h,NaOH dosage of 2%,and Na2SO3 dosage of 10%.The cooking yield of bamboo chips was 89.5%,and the carding yield of natural bamboo fiber was 43.0% under the optimum conditions.The length,diameter,tensile strength,and elastic modulus of the obtained fiber were 36.71 mm,0.285 mm,407 MPa,and 27.7 GPa,respectively.XRD analysis and SEM observations showed that the technology used in this study can produce bright and compact natural bamboo fibers with high crystallinity. | Kaixuan Li Qingxian Miao He Zhao Jiawei Yang Haitao Cheng Lihui Chen | 2020 | Paper And Biomaterials2020，5，2： | 6 |
| 11 | Cromakalin pretreatment affects mitochondrial structure and function in a rat model of ischemia/reperfusion injury显示文摘BACKGROUND:Mitochondrial structural changes and energy dysmetabolism frequently occur subsequent to cerebral ischemia.Adenosine triphosphate(ATP)-sensitive potassium channel openers exhibit protective effects on cerebral ischemia/reperfusion injury.OBJECTIVE:To validate the effects of cromakalin on mitochondrial structure and function in ischemic penumbra brain tissue in a rat model of middle cerebral artery occlusion(MCAO).DESIGN,TIME AND SETTING:The present single-factor analysis of variance,randomized,controlled,animal experiment was performed at the Institute of Brain Science,Affiliated Hospital of Qingdao University Medical College between October 2007 and March 2008.MATERIALS:Forty male,Wistar rats were randomly divided into four groups,with 10 rats per group:sham-operated,MCAO,MCAO+ATP-sensitive potassium channel opener(cromakalin),and MCAO+cromakalin+ATP-sensitive potassium channel blocking agent(glibenclamide).METHODS:Focal cerebral ischemia/reperfusion injury was induced by MCAO in all groups except the sham-operated group.The MCAO cromakalin group was administered 10 mg/kg cromakalin(i.p.) prior to MCAO induction.The MCAO+cromakalin+glibenclamide group received an injection of 10 mg/kg cromakalin(i.v.),and subsequently an injection of 10 mg/kg cromakalin(i.p.) prior to MCAO induction.MAIN OUTCOME MEASURES:At 24 hours after cerebral ischemia/reperfusion injury,cellular apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate(dUTP) nick-end labeling technique.Cytochrome C expression was measured by immunohistochemistry.In addition,mitochondrial swelling,membrane fluidity,membrane phospholipid and malonaldehyde(MDA) contents,as well as Na+-K+-ATPase,Ca2 +-ATPase,and superoxide dismutase(SOD) activities were determined.RESULTS:Compared with the sham-operated group,the three ischemia groups exhibited significantly elevated mitochondrial MDA content,reduced membrane phospholipid and ATP contents,down-regulated membrane fluidity,and reduced Na+-K+-ATPase,Ca2+-ATPase,and SOD activities(P < 0.05-0.01).In the MCAO+cromakalin group,the number of apoptotic cells decreased,and cytochrome C expression,as well as MDA content,were reduced.However,ATP content and Na+-K+-ATPase,Ca2+-ATPase,and SOD activities significantly increased compared with the MCAO group(P < 0.05-0.01).Glibenclamide noticeably antagonized cromakalin protection of mitochondria.CONCLUSION:Pretreatment with the ATP-sensitive potassium channel opener cromakalin increased mitochondrial Na+-K+-ATPase,Ca2+-ATPase,and SOD activities,decreased neuronal apoptosis,and inhibited cytochrome C expression following MCAO. | Shilei Wang Peng Wang Qingxian Chang Yu Li Yan Jiang Shiduan Wang | 2008 | Neural Regeneration Research2008，3，9： | 6 |
| 12 | Upgrading Paper-grade Softwood Kraft Pulp to Dissolving Pulp by Cold Caustic Extraction显示文摘Cold caustic extraction has potential applications in the production of dissolving-grade pulps due to its ability to selectively remove hemicellulose from lignocellulosic materials. In this study,we demonstrate the conversion of paper-grade kraft pulp into dissolving pulp by a single-stage cold caustic extraction. Under the extraction conditions of 12 wt% NaOH lye,11% pulp consistency,a temperature of 35℃,and 2 h,a paper-grade softwood kraft pulp was purified to high-grade dissolving pulp with 97. 1% α-cellulose content,1. 2% pentosane content,and narrowed molecular weight distribution. The resulting extraction filtrate was concentrated by nano-filtration to obtain the hemicellulose content of 59. 0 g / L,while the permeate was a clear Na OH solution with 10. 9 wt% concentration. A process configuration was also proposed,integrating this cold caustic extraction process with existing pulp and paper production and multi-purpose utilization of the extraction filtrate. | Chao Tian QingXian Miao LinQiang Zheng YongHao Ni | 2016 | Paper And Biomaterials2016，1，1： | 5 |
| 13 | Adaptive functional link network control of near-space vehicles with dynamical uncertainties显示文摘The control law design for a near-space hypersonic vehicle(NHV) is highly challenging due to its inherent nonlinearity,plant uncertainties and sensitivity to disturbances.This paper presents a novel functional link network(FLN) control method for an NHV with dynamical thrust and parameter uncertainties.The approach devises a new partially-feedback-functional-link-network(PFFLN) adaptive law and combines it with the nonlinear generalized predictive control(NGPC) algorithm.The PFFLN is employed for approximating uncertainties in flight.Its weights are online tuned based on Lyapunov stability theorem for the first time.The learning process does not need any offline training phase.Additionally,a robust controller with an adaptive gain is designed to offset the approximation error.Finally,simulation results show a satisfactory performance for the NHV attitude tracking,and also illustrate the controller's robustness. | Yanli Du Qingxian Wu Changsheng Jiang Jie Wen | 2010 | Journal of Systems Engineering and Electronics2010，21，5： | 5 |
| 14 | Robust control for an unmanned helicopter with constrained flapping dynamics显示文摘In this paper, a neural network based adaptive prescribed performance control scheme is proposed for the altitude and attitude tracking system of the unmanned helicopter in the presence of state and output constraints. For handling the state constraints, the barrier Lyapunov function and the saturation function are employed. And, the prescribed performance method is used to deal with the flapping angle constraints for the unmanned helicopter. It is proved that the proposed control approach can ensure that all the signals of the resulting closed-loop system are bounded, and the tracking errors are within the prescribed performance bounds for all time. The numerical simulation is given to illustrate the performance of the proposed scheme. | Rong LI Mou CHEN Qingxian WU | 2018 | Chinese Journal of Aeronautics2018，31，11： | 5 |
| 15 | Computational fluid dynamics simulation of friction stir welding:A comparative study on different frictional boundary conditions显示文摘Numerical simulation based on computational fluid dynamics(CFD) is a useful approach for quantitatively investigating the underlying thermal-mechanical conditions during FSW, such as temperature field and material deformation field. One of the critical issues in CFD simulation of FSW is the use of the frictional boundary condition, which represents the friction between the welding tool and the workpiece in the numerical models. In this study, three-dimensional numerical simulation is conducted to analyze the heat transfer and plastic deformation behaviors during the FSW of AA2024. For comparison purposes,both the boundary velocity(BV) models and the boundary shear stress(BSS) models are employed in order to assess their performances in predicting the temperature and material deformation in FSW. It is interesting to note that different boundary conditions yield similar predictions on temperature, but quite different predictions on material deformation. The numerical predictions are compared with the experimental results. The predicted deformation zone geometry by the BSS model is consistent with the experimental results while there is large difference between the predictions by the BV models and the experimental measurements. The fact that the BSS model yields more reasonable predictions on the deformation zone geometry is attributed to its capacity to automatically adjust the contact state at the tool/workpiece interface. Based on the favorable predictions on both the temperature field and the material deformation field, the BSS model is suggested to have a better performance in numerical simulation of FSW than the BV model. | Gaoqiang Chen Qingxian Ma Shuai Zhang Jianjun Wu Gong Zhang Qingyu Shi | 2018 | Journal of Materials Science & Technology2018，34，1： | 5 |
| 16 | Novel approach of crater detection by crater candidate region selection and matrix-pattern-oriented least squares support vector machine显示文摘Impacted craters are commonly found on the surface of planets, satellites, asteroids and other solar system bodies. In order to speed up the rate of constructing the database of craters, it is important to develop crater detection algorithms. This paper presents a novel approach to automatically detect craters on planetary surfaces. The approach contains two parts: crater candidate region selection and crater detection. In the first part, crater candidate region selection is achieved by Kanade-Lucas-Tomasi (KLT) detector. Matrix-pattern-oriented least squares support vector machine (MatLSSVM), as the matrixization version of least square support vector machine (SVM), inherits the advantages of least squares support vector machine (LSSVM), reduces storage space greatly and reserves spatial redundancies within each image matrix compared with general LSSVM. The second part of the approach employs MatLSSVM to design classifier for crater detection. Experimental results on the dataset which comprises 160 preprocessed image patches from Google Mars demonstrate that the accuracy rate of crater detection can be up to 88%. In addition, the outstanding feature of the approach introduced in this paper is that it takes resized crater candidate region as input pattern directly to finish crater detection. The results of the last experiment demonstrate that MatLSSVM-based classifier can detect crater regions effectively on the basis of KLT-based crater candidate region selection. | Ding Meng Cao Yunfeng Wu Qingxian | 2013 | Chinese Journal of Aeronautics2013，26，2： | 4 |
| 17 | Effectiveness and feasibility of transradial approaches for primary percutaneous coronary intervention in patients with acute myocardial infarction显示文摘Objective: To evaluate the efficacy and feasibility of the transradial approach for primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction(AMI). Methods: 195 patients with acute myocardial infarction were randomly divided into two groups according to the different PCI operation pathways. 105 cases were assigned to the transfemoral artery group and 90 cases to the transradial artery group. We analyzed the data from the two groups, including the achievement ratio of paracentesis, cannulation time, the time from local anesthesia to the first time balloon inflation, the time of the total procedure, achievement ratio of PCI, incidence rate of vascular complications, total duration of hospitalization, and the six-month follow-up results in both groups. Results: Our results showed that the achievement ratio of arteriopuncture, cannulation time and the time from local anesthesia to the first time balloon inflation in the transradial and transfemoral groups were 98.9% vs. 100%, 3.15 ± 1.56 min vs. 2.86 ± 0.97 min, and 18.56 ± 4.37 min vs. 17.75 ± 3.21 min, respectively. These differences between the two groups were not statistically significant. The total operating time was 29.75 ± 4.38 min for the transradial group and 27.89 ± 3.95 min(P < 0.05) for the transfemoral group. The operation achievement ratio in the transradial group was 96.7%, and 96.2% in the transfemoral group. The incidence of puncture point complications was 2.2% in the transradial group and 11.4% in the transfemoral group, and this difference was significant. The duration of hospitalization was 10.56 ± 2.85 days for the transradial group and 13.78 ± 3.15 days(P < 0.05) for the transfemoral group. At the six-month follow-up, the rate of survival without cardiac event was 86.1% vs. 86.4% respectively in the transradial and transfemoral groups(P > 0.05). Conclusion: The transradial approach was as effective as the transfemoral approach, and there were fewer puncture point complications as well as a shorter span of hospitalization in the transradial group. PCI via the transradial approach is safe, effective and feasible in patients with AMI. | Lijun Gan Qingxian Li Rong Liu Yuxin Zhao Jianjun Qiu Yuhua Liao | 2009 | Journal of Nanjing Medical University2009，23，4： | 3 |
| 18 | Considering Monopoly Maintenance Cost for an Automobile Purchase in China: A DEA-Based Approach显示文摘With the fast growing economy,China has become the biggest automobile market in the world.Many Chinese families buy automobiles to promote individual wellbeing and facilitate the convenience of lives.Automobile purchase has become a general and important decision for a Chinese family.However,it is always difficult to make a decision on the automobile purchase that balance the automobiles performance and its cost.Moreover,the automobile maintenance market in China is monopolistic.Thus,the maintenance cost is a significant consideration in automobile purchase decision.This paper employs the concept of data envelopment analysis(DEA)to measure cost performance of the automobile with considering the monopoly maintenance cost.The RCA(ratio of the total price of accessories of an automobile to the price of the automobile)100 index system is used to represent the maintenance cost of each automobile.The structure of the automobile maintenance market can be reflected with including the RCA 100 index system in the performance evaluation.Results of the case study of 28 automobiles in China verify the necessity of considering the maintenance cost in automobile purchase decision. | DAI Qianzhi LI Lin LEI Xiyang AN Qingxian TANG Xiao | 2019 | Journal of Systems Science & Complexity2019，32，4： | 3 |
| 19 | Disturbance observer-based optimal longitudinal trajectory control of near space vehicle显示文摘Dear editor,Near-space vehicles (NSVs) have been proposed as a more reliable and efficient alternative to traditional flight vehicles because of their high mobility and multitask mode, as well as their excellent performance in high-speed flights (1)In practical applications, the design of an efficient trajectory control scheme for an NSV is crucial。 | Rongsheng XIA Qingxian WU Mou CHEN | 2019 | Science China(Information Sciences)2019，62，5： | 3 |
| 20 | Delay-dependent robust H∞ control for uncertain fuzzy hyperbolic systems with multiple delays显示文摘The robust H∞ control problem was considered for a class of fuzzy hyperbolic model(FHM)systems with parametric uncertainties and multiple delays.First,FHM modeling method was presented for time-delay nonlinear systems.Then,by using Lyapunov–Krasov- skii approaches,delay-dependent suficient condition for the existence of a kind of state feedback controller was proposed,which was expressed as linear matrix inequalities(LMIs).The controller can guarantee that the resulting closed-loop system is robustly asymptot- ically stable with a prescribed H∞ performance level for all admissible uncertainties and time-delay.Finally,a simulation example was provided to illustrate the effectiveness of the proposed approach. | Huaguang Zhang Qingxian Gong Yingchun Wang | 2008 | Progress in Natural Science:Materials International2008，18，1： | 2 |
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