9 results on '"Guanqun Xu"'
Search Results
2. Multi-Battery Block Module Power Converter for Electric Vehicle Driven by Switched Reluctance Motors
- Author
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Xiaoshu Zan, Guanqun Xu, Tiejun Zhao, Ruiming Wang, and Linwang Dai
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Battery (electricity) ,business.product_category ,General Computer Science ,Computer science ,Photovoltaic system ,electric vehicle ,General Engineering ,multi-battery block module ,Topology (electrical circuits) ,Switched reluctance motors ,Automotive engineering ,Switched reluctance motor ,TK1-9971 ,charge ,Electromagnetic coil ,Electric vehicle ,General Materials Science ,Power semiconductor device ,Electric-vehicle battery ,Electrical engineering. Electronics. Nuclear engineering ,business - Abstract
To improve the endurance and charging flexibility of electric vehicle battery packs, this paper proposes a multi-battery block module (MBM) topology for four-phase switched reluctance motors (SRMs), which not only allows flexible electric vehicle operation, but also achieves fast demagnetization and excitation. By integrating the multi-battery block module and photovoltaic (PV) panel into an asymmetrical half-bridge (AHB) converter, the MBM topology is designed to supply a multilevel bus voltage for the SRM drive. To improve the endurance of battery packs, a PV panel is also added to the topology to charge battery packs when the system is stationary. According to the different operation requirements, multiple power supply modes and charging modes can be realized by controlling the power devices in the proposed MBM topology. The simulation results based on the MATLAB/Simulink platform and the experimental results on a four-phase 8 / 6 switched reluctance motor verify the effectiveness of the proposed design.
- Published
- 2021
3. Control Strategy of Parallel Systems with Efficiency Optimisation in Switched Reluctance Generators
- Author
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Tiejun Zhao, Xiaoshu Zan, Yi Gong, Hang Lin, and Guanqun Xu
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010302 applied physics ,TK7800-8360 ,Computer science ,parallel system ,020208 electrical & electronic engineering ,Control (management) ,02 engineering and technology ,01 natural sciences ,Switched reluctance motor ,switched reluctance generator ,Control theory ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electronics ,Differential evolution algorithm ,efficiency optimization ,differential evolution algorithm - Abstract
To solve motor heating and life shortening of parallel switched reluctance generator (SRG) induced by uneven output currents due to different external characteristics, we generally adopt current sharing control (CSC) to make each parallel generator undertake large load currents on average to improve the reliability of parallel power generation system. However, the method usually causes additional loss of power because it does not consider the efficiency characteristics of each parallel generator. Therefore, with the efficiency expression for the parallel system of SRG established and analysed, the control strategy based on differential evolution (DE) algorithm is proposed as a mechanism by which to enhance generating capacity and reliability of multi-machine power generation from the perspective of efficiency optimisation. We re-adjust the reference current of each parallel generator to transform the working point of each generator and implement the efficiency optimisation of parallel system. The performance of the proposed control method is evaluated in detail by the simulation and experiment, and comparison with traditional CSC is carried out as well.
- Published
- 2021
4. Wind turbine load estimation using machine learning and transfer learning
- Author
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Guanqun Xu, Wei Yu, and Taeseong Kim
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History ,Computer Science Applications ,Education - Abstract
Machine learning method has always been popular to solve wind turbine related problems at a data level. However, with the limitation of the availability of relevant data, transfer learning has gained increasing attention. In this study, traditional machine learning method of artificial neural networks (ANN), together with parameter-based transfer learning method has been used to estimate wind turbine load. First, ANN load model was built for DTU 10MW wind turbine as well as NREL 5MW wind turbine. Then, parameter-based transfer learning has been applied to the above-mentioned models to estimate load for a different turbine type or two mixed turbine types. Results indicate that ANN method provides good estimation on wind turbine fatigue load. For DTU 10MW ANN model, the trend of accuracy becomes steady as the number of input samples increases and 1500 samples is deemed as the optimal number of samples for training DTU 10MW. In addition, with transfer learning, it was succeeded in building NREL 5MW model with corresponding DTU 10MW pretrained model but failed in establishing mixed dataset model neither with DTU 10MW nor with NREL 5MW pretrained model.
- Published
- 2022
5. Inhibitor eradication and bleeding management of acquired hemophilia A: a single center experience in China
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Naifang Ye, Wenman Wu, Xiaoqian Xu, Guanqun Xu, Zhenzhen Liu, Xuefeng Wang, and Fang Wu
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Fviii activity ,Adult ,Male ,congenital, hereditary, and neonatal diseases and abnormalities ,Pediatrics ,medicine.medical_specialty ,China ,Adolescent ,Hemorrhage ,Single Center ,Hemophilia A ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,hemic and lymphatic diseases ,medicine ,Humans ,Child ,health care economics and organizations ,Aged ,business.industry ,Hematology ,Middle Aged ,Coagulation ,030220 oncology & carcinogenesis ,Acquired hemophilia ,Female ,Blood Coagulation Tests ,business ,030215 immunology ,Rare disease - Abstract
Objectives: Acquired hemophilia A (AHA) is a rare disease resulting from autoantibodies against coagulation factor VIII that leads to spontaneous bleeding. This study reports the clinical character...
- Published
- 2019
6. Association of Major Depression With Risk of Ischemic Heart Disease in a Mega‐Cohort of Chinese Adults: The China Kadoorie Biobank Study
- Author
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Na Liu, Xiong‐Fei Pan, Canqing Yu, Jun Lv, Yu Guo, Zheng Bian, Ling Yang, Yiping Chen, Tangchun Wu, Zhengming Chen, An Pan, Liming Li, Junshi Chen, Rory Collins, Richard Peto, Garry Lancaster, Xiaoming Yang, Alex Williams, Margaret Smith, Yumei Chang, Guoqing Zhao, Lixue Wu, Can Hou, Zengchang Pang, Shaojie Wang, Yun Zhang, Kui Zhang, Silu Liu, Zhonghou Zhao, Shumei Liu, Zhigang Pang, Weijia Feng, Shuling Wu, Liqiu Yang, Huili Han, Hui He, Xianhai Pan, Shanqing Wang, Hongmei Wang, Xinhua Hao, Chunxing Chen, Shuxiong Lin, Xiaoshu Hu, Minghao Zhou, Ming Wu, Yeyuan Wang, Yihe Hu, Liangcai Ma, Renxian Zhou, Guanqun Xu, Baiqing Dong, Naying Chen, Ying Huang, Mingqiang Li, Jinhuai Meng, Zhigao Gan, Jiujiu Xu, Yun Liu, Xianping Wu, Yali Gao, Ningmei Zhang, Guojin Luo, Xiangsan Que, Xiaofang Chen, Pengfei Ge, Jian He, Xiaolan Ren, Hui Zhang, Enke Mao, Guanzhong Li, Zhongxiao Li, Jun He, Guohua Liu, Baoyu Zhu, Gang Zhou, Shixian Feng, Yulian Gao, Tianyou He, Li Jiang, Jianhua Qin, Huarong Sun, Liqun Liu, Min Yu, Yaping Chen, Zhixiang Hu, Jianjin Hu, Yijian Qian, Zhiying Wu, Lingli Chen, Wen Liu, Guangchun Li, Huilin Liu, Xiangquan Long, Youping Xiong, Zhongwen Tan, Xuqiu Xie, and Yunfang Peng
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Adult ,Male ,Gerontology ,China ,Epidemiology ,Myocardial Ischemia ,Coronary Artery Disease ,Disease ,030204 cardiovascular system & hematology ,Risk Assessment ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Humans ,Medicine ,International Statistical Classification of Diseases and Related Health Problems ,Prospective Studies ,030212 general & internal medicine ,Prospective cohort study ,Depression (differential diagnoses) ,Aged ,Proportional Hazards Models ,Original Research ,Depressive Disorder, Major ,prospective cohort study ,Chinese ,business.industry ,Incidence ,Incidence (epidemiology) ,Hazard ratio ,Middle Aged ,ischemic heart disease ,Biobank ,3. Good health ,Primary Prevention ,Mental Health ,depression ,Cohort ,Female ,Cardiology and Cardiovascular Medicine ,business ,Follow-Up Studies ,Demography - Abstract
Background Increasing evidence has suggested that major depression ( MD ) is associated with an increased risk of ischemic heart disease ( IHD ). We examined this association in Chinese adults using data from the China Kadoorie Biobank study. Methods and Results Over 0.5 million adults aged 30 to 79 years were followed from baseline interview (2004–2008) until December 31, 2013. Past year MD was measured with the modified Chinese version of Composite International Diagnostic Interview‐Short Form at baseline. Incident IHD cases were identified through linkage to related medical databases, and defined as having International Statistical Classification of Diseases and Related Health Problems 10th Revision codes of I20 to I25. Cox proportional hazards regression models were used to estimate hazard ratios and 95% CI s for the MD ‐ IHD association with adjustment for sociodemographic variables and established cardiovascular risk factors. During 3 423 542 person‐years of follow‐up, 24 705 incident IHD cases were documented. Higher IHD incidence was observed in participants with MD compared with those without (8.76 versus 7.21 per 1000 person‐years), and the multivariable‐adjusted hazard ratio was 1.32 (95% CI 1.15–1.53). Geographic location modified the association ( P for interaction=0.005), and a positive association was observed in urban residents (hazard ratio 1.72; 95% CI 1.39–2.14) but not rural residents (1.13; 0.93–1.37). Compared with participants without depressive symptoms, the hazard ratio (95% CI ) of IHD was 1.13 (1.04–1.23) for those with depressive symptoms only and 1.33 (1.15–1.53) for those with MD . Conclusions Past year major depression was associated with an increased risk of IHD in Chinese adults, independent of other major cardiovascular risk factors.
- Published
- 2016
7. Decreased Factor V Ameliorates Bleeding Diathesis in Patients with Combined Deficiency of Factor V and Factor VIII
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Ding Qiulan, Guanqun Xu, Yanyan Shao, Wang Xuefeng, and Wenman Wu
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medicine.medical_specialty ,biology ,business.industry ,Prednimustine ,Immunology ,Factor V ,Cell Biology ,Hematology ,medicine.disease ,Biochemistry ,Bleeding diathesis ,chemistry.chemical_compound ,Basal (phylogenetics) ,Thrombin ,Endocrinology ,Tissue factor pathway inhibitor ,Coagulation ,chemistry ,Internal medicine ,medicine ,biology.protein ,business ,Desmopressin ,medicine.drug - Abstract
Combined factor V (FV) and factor VIII (FVIII) deficiency (F5F8D) is a rare autosomal recessive bleeding disorder caused by mutations in LMAN1 and MCFD2 gene. Though characterized with deficiencies of both FV and FVIII, it failed to lead to more severe bleeding than single defect of FVIII in similar degree. Our study on F5F8D patients revealed that mild decrease of FV and FVIII had counteractive effect on blood coagulation. Out of 5 subjects investigated, three showed potent thrombin generation as observed in thrombin generation assay (TGA), with peak heights ranging from 138 nM to 166 nM, compared with 81 nM in normal plasma when coagulation was initiated with 1pM TF. The same trend was seen when the TF concentration was increased to 5 pM. Supplement of FV and FVIII, however, demonstrated distinct impact in TGA, with FVIII addition inducing more thrombin generation whereas higher FV level failed to further boost thrombin generation despite the shortened lag time. FV is a Janus-faced protein and suppresses blood coagulation by protecting TFPI from degradation.Similar to patients with severe FV deficiency, both total and free TFPI levels also decreased slightly in F5F8D patients. Total TFPI levels decreased from healthy donors (65.95±8.35 ng/mL) to F5F8D patients (65.79±12.99 ng/mL), to severe FV-deficient patients (51.30±11.15 ng/mL, P=0.037). A more pronounced trend was observed for free TFPI levels, as free TFPI in healthy controls were 12.68±2.91 ng/mL, higher than those in F5F8D (4.73±1.31 ng/mL, P=0.004), and in severe FV-deficient patients (3.81±1.03 ng/mL, P=0.004).The lowered TFPI in patients with F5F8D may neutralize the impact of FV and FVIII deficiency on blood coagulation. Desmopressin (DDAVP) increases endogenous FVIII and is used in the management of mild hemophilia A patients. In current study, 4 patients with F5F8D were treated with DDAVP. The administration of DDAVP saw no elevation of FV yet the increase of FVIII. The mean basal FV and FVIII levels were 11.5±3.4% and 15.1±4.8% respectively. The peak value of FVIII levels rose to 66.1±20.5% 30 minutes after the administration, and was sustained at two-folds of the baseline four hours post administration. The distinctive changes brought by combined FV and FVIII deficiencies on blood coagulation functions indicates the lone FVIII replacement without FV supplement might be sufficient in bleeding management of patients with F5F8D. DDAVP can be considered as a potential substitute for FVIII concentrate in the treatment of F5F8D patients. Disclosures No relevant conflicts of interest to declare.
- Published
- 2018
8. Effectiveness of a television advertisement campaign on giving cigarettes in a chinese population
- Author
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Jian Su, Guanqun Xu, Jiuhua Ma, Zumin Shi, Yu Qin, Yihe Hu, and Quanyong Xiang
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Program evaluation ,Adult ,Male ,China ,Adolescent ,Epidemiology ,Population ,Health Behavior ,Smoking Prevention ,Health Promotion ,Young Adult ,Advertising ,Surveys and Questionnaires ,Cardiovascular Disease ,Chi-square test ,Social Norms ,Medicine ,Humans ,Social Change ,education ,education.field_of_study ,Chinese population ,business.industry ,giving cigarettes ,Tobacco control ,General Medicine ,Middle Aged ,Health promotion ,anti-tobacco television campaign ,tobacco control ,Female ,Television ,Original Article ,Health behavior ,Recall rate ,business ,Program Evaluation - Abstract
BACKGROUND Anti-tobacco television advertisement campaigns may convey messages on smoking-related health consequences and create norms against giving cigarettes. METHODS Altogether, 156 and 112 slots of a television advertisement "Giving cigarettes is giving harm" were aired on Suzhou and Yizheng, respectively, over one month in 2010. Participants were recruited from 15 locations in Suzhou and 8 locations in Yizheng using a street intercept method. Overall 2306 residents aged 18-45 years completed questionnaires, including 1142 before the campaign and 1164 after, with respective response rates of 79.1% and 79.7%. Chi square tests were used to compare the difference between categorical variables. RESULTS After the campaign, 36.0% of subjects recalled that they had seen the advertisement. Residents of Suzhou had a higher recall rate than those of Yizheng (47.6% vs. 20.6%, P < 0.001). The rate of not giving cigarettes dropped from 32.1% before the campaign to 28.5% after (P = 0.05). In the post-campaign evaluation, participants who reported seeing the advertisement were more likely not to give cigarettes in the future than those who reported not seeing the advertisement (38.7% vs. 27.5%, P < 0.001). CONCLUSIONS Our study showed that an anti-tobacco television advertisements helped change societal norms and improve health behavior. Continuous and adequate funding of anti-tobacco media campaigns targeted at different levels of the general population is needed, in conjunction with a comprehensive tobacco control effort.
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- 2014
9. Prevalence and correlates of airflow obstruction in ∼317,000 never-smokers in China
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Margaret, Smith, Liming, Li, Mareli, Augustyn, Om, Kurmi, Junshi, Chen, Rory, Collins, Yu, Guo, Yabin, Han, Jingxin, Qin, Guanqun, Xu, Jian, Wang, Zheng, Bian, Gang, Zhou, Richard, Peto, Zhengming, Chen, and W, Jia
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Adult ,Male ,China ,Respiration ,Smoking ,Vital Capacity ,Middle Aged ,Asthma ,Body Mass Index ,Pulmonary Disease, Chronic Obstructive ,Cross-Sectional Studies ,Spirometry ,Air Pollution, Indoor ,Forced Expiratory Volume ,Surveys and Questionnaires ,Odds Ratio ,Prevalence ,Humans ,Female ,Cooking ,Aged - Abstract
In China, the burden of chronic obstructive disease (COPD) is high in never-smokers but little is known about its causes in this group. We analysed data on 287 000 female and 30 000 male never-smokers aged 30-79 years from 10 regions in China, who participated in the China Kadoorie Biobank baseline survey (2004-2008). Prevalence of airflow obstruction (AFO) (pre-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC)0.7 and below the lower limit of normal (LLN)) was estimated, by age and region. Cross-sectional associations of AFO (FEV1/FVC0.7), adjusted for confounding, were examined. AFO prevalence defined as FEV1/FVC0.7 was 4.0% in females and 5.1% in males (mean ages 51 and 54 years, respectively). AFO prevalence defined as FEV1/FVCLLN was 5.9% and 5.2%, respectively. In females, odds ratios of AFO were positively associated with lower household income (1.63, 95% CI 1.55-1.72 for lowest versus highest income groups), prior tuberculosis (2.36, 95% CI 2.06-2.71), less education (1.17, 95% CI 1.12-1.23 for no schooling versus college education), rural region and lower body mass index. AFO was positively associated with cooking with coal but not with other sources of household air pollution. Associations were similar for males. AFO is prevalent in Chinese never-smokers, particularly among those with low socioeconomic status or prior tuberculosis, and in rural males.
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- 2014
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