Due to the bus characteristics of large quality,high center of gravity and narrow wheelbase,the research of its yaw stability control(YSC)system has become the focus in the field of vehicle system dynamics.However,the...Due to the bus characteristics of large quality,high center of gravity and narrow wheelbase,the research of its yaw stability control(YSC)system has become the focus in the field of vehicle system dynamics.However,the tire nonlinear mechanical properties and the effectiveness of the YSC control system are not considered carefully in the current research.In this paper,a novel adaptive nonsingular fast terminal sliding mode(ANFTSM)control scheme for YSC is proposed to improve the bus curve driving stability and safety on slippery roads.Firstly,the STI(Systems Technologies Inc.)tire model,which can effectively reflect the nonlinear coupling relationship between the tire longitudinal force and lateral force,is established based on experimental data and firstly adopted in the bus YSC system design.On this basis,a more accurate bus lateral dynamics model is built and a novel YSC strategy based on ANFTSM,which has the merits of fast transient response,finite time convergence and high robustness against uncertainties and external disturbances,is designed.Thirdly,to solve the optimal allocation problem of the tire forces,whose objective is to achieve the desired direct yaw moment through the effective distribution of the brake force of each tire,the robust least-squares allocation method is adopted.To verify the feasibility,effectiveness and practicality of the proposed bus YSC approach,the TruckSim-Simulink co-simulation results are finally provided.The co-simulation results show that the lateral stability of bus under special driving conditions has been significantly improved.This research proposes a more effective design method for bus YSC system based on a more accurate tire model.展开更多
目的探索针对暗娼(Female sex worker,FSW)人群开展干预工作的新模式。方法在广东江门、海南琼海培训临床医生参与FSW人群的外展工作,在现场提供健康教育、咨询、体检、检测等性病和生殖健康服务。以广西梧州高干队的常规外展服务模式...目的探索针对暗娼(Female sex worker,FSW)人群开展干预工作的新模式。方法在广东江门、海南琼海培训临床医生参与FSW人群的外展工作,在现场提供健康教育、咨询、体检、检测等性病和生殖健康服务。以广西梧州高干队的常规外展服务模式为对照。结果在外展工作中,通过临床医生提供的性病服务进一步提高了FSW人群性病预防知识的知晓率和可疑性病患者的转介成功率,降低了FSW人群的梅毒感染率。结论比起常规的外展模式来,由有临床背景的医务人员参与的、以性病服务为基础的FSW人群的干预模式更容易接近低档场所的目标人群,能够为目标人群所接纳,同时外展服务的质量也得到了进一步提高。展开更多
The objective of the study was to develop a remote sensing （i.e., Landsat-8 and MODIS）-based agricultural drought indicator （ADI） at 30-m spatial resolution and 8-day temporal resolution and also to evaluate its p...The objective of the study was to develop a remote sensing （i.e., Landsat-8 and MODIS）-based agricultural drought indicator （ADI） at 30-m spatial resolution and 8-day temporal resolution and also to evaluate its performance over a heterogeneous agriculture dominant semi-arid region in Jordan. Firstly, we used principal component analysis （PCA） to evaluate the correlations among six commonly used remote sensing-derived agricultural drought related variables. The variables included normalized difference water index （NDWI）, normalized difference vegetation index （NDVI）, visible and shortwave drought index （VSDI）, normalized multiband drought index （NMDI）, moisture stress index （MSI）, and land surface temperature （LST）. Secondly, we integrated the relatively less correlated variables （that were found to be NDWI, VSDI, and LST） to generate four agricultural drought categories/conditions （i.e., wet, mild drought, moderate drought, and severe drought）. Finally, we evaluated the ADI maps against a set of 8-day ground-based standardized precipitation index values （i.e., SPI-I, SPI-2, ..., SPLS） by use of confusion matrices and observed the best results for SPI-4 （i.e., overall accuracy and Kappa-values were 83% and 76%, respectively） and SPI-5 （i.e., overall accuracy and Kappa-values were 85% and 78%, respectively）. The results demonstrated that the method would be valuable for monitoring agricultural drought conditions in semi-arid regions at both a reasonably high spatial resolution （i.e., 30-m） and a short time period （i.e., 8-day）.展开更多
The STI stress effect is investigated based on the 0.13 m SOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences（IMECAS）. It shows that the threshold voltage and mobility are a...The STI stress effect is investigated based on the 0.13 m SOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences（IMECAS）. It shows that the threshold voltage and mobility are all affected by the STI stress. The absolute value of the threshold voltage of NMOS and PMOS increased by about 10%, the saturation current of NMOS decreases by about 20%, while the saturation current of PMOS increases by about 20%. It is also found that the lower temperature enhances the STI stress and then influences the device performance further. Then a macro model for this effect is proposed and is well verified.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52072161,U20A20331)China Postdoctoral Science Foundation(Grant No.2019T120398)+2 种基金State Key Laboratory of Automotive Safety and Energy of China(Grant No.KF2016)Vehicle Measurement Control and Safety Key Laboratory of Sichuan Province(Grant No.QCCK2019-002)Young Elite Scientists Sponsorship Program by CAST(Grant No.2018QNRC 001).
文摘Due to the bus characteristics of large quality,high center of gravity and narrow wheelbase,the research of its yaw stability control(YSC)system has become the focus in the field of vehicle system dynamics.However,the tire nonlinear mechanical properties and the effectiveness of the YSC control system are not considered carefully in the current research.In this paper,a novel adaptive nonsingular fast terminal sliding mode(ANFTSM)control scheme for YSC is proposed to improve the bus curve driving stability and safety on slippery roads.Firstly,the STI(Systems Technologies Inc.)tire model,which can effectively reflect the nonlinear coupling relationship between the tire longitudinal force and lateral force,is established based on experimental data and firstly adopted in the bus YSC system design.On this basis,a more accurate bus lateral dynamics model is built and a novel YSC strategy based on ANFTSM,which has the merits of fast transient response,finite time convergence and high robustness against uncertainties and external disturbances,is designed.Thirdly,to solve the optimal allocation problem of the tire forces,whose objective is to achieve the desired direct yaw moment through the effective distribution of the brake force of each tire,the robust least-squares allocation method is adopted.To verify the feasibility,effectiveness and practicality of the proposed bus YSC approach,the TruckSim-Simulink co-simulation results are finally provided.The co-simulation results show that the lateral stability of bus under special driving conditions has been significantly improved.This research proposes a more effective design method for bus YSC system based on a more accurate tire model.
文摘目的探索针对暗娼(Female sex worker,FSW)人群开展干预工作的新模式。方法在广东江门、海南琼海培训临床医生参与FSW人群的外展工作,在现场提供健康教育、咨询、体检、检测等性病和生殖健康服务。以广西梧州高干队的常规外展服务模式为对照。结果在外展工作中,通过临床医生提供的性病服务进一步提高了FSW人群性病预防知识的知晓率和可疑性病患者的转介成功率,降低了FSW人群的梅毒感染率。结论比起常规的外展模式来,由有临床背景的医务人员参与的、以性病服务为基础的FSW人群的干预模式更容易接近低档场所的目标人群,能够为目标人群所接纳,同时外展服务的质量也得到了进一步提高。
基金the University of Calgary, Canada and Yarmouk University, Jordan for providing partial financial support in the form of awards to Mr. Khaled HAZAYMEH and the National Sciences and Engineering Research Council (NSERC), Canada for a Discovery grant to Dr. Quazi HASSAN
文摘The objective of the study was to develop a remote sensing （i.e., Landsat-8 and MODIS）-based agricultural drought indicator （ADI） at 30-m spatial resolution and 8-day temporal resolution and also to evaluate its performance over a heterogeneous agriculture dominant semi-arid region in Jordan. Firstly, we used principal component analysis （PCA） to evaluate the correlations among six commonly used remote sensing-derived agricultural drought related variables. The variables included normalized difference water index （NDWI）, normalized difference vegetation index （NDVI）, visible and shortwave drought index （VSDI）, normalized multiband drought index （NMDI）, moisture stress index （MSI）, and land surface temperature （LST）. Secondly, we integrated the relatively less correlated variables （that were found to be NDWI, VSDI, and LST） to generate four agricultural drought categories/conditions （i.e., wet, mild drought, moderate drought, and severe drought）. Finally, we evaluated the ADI maps against a set of 8-day ground-based standardized precipitation index values （i.e., SPI-I, SPI-2, ..., SPLS） by use of confusion matrices and observed the best results for SPI-4 （i.e., overall accuracy and Kappa-values were 83% and 76%, respectively） and SPI-5 （i.e., overall accuracy and Kappa-values were 85% and 78%, respectively）. The results demonstrated that the method would be valuable for monitoring agricultural drought conditions in semi-arid regions at both a reasonably high spatial resolution （i.e., 30-m） and a short time period （i.e., 8-day）.
文摘The STI stress effect is investigated based on the 0.13 m SOI process developed by the Institute of Microelectronics of the Chinese Academy of Sciences（IMECAS）. It shows that the threshold voltage and mobility are all affected by the STI stress. The absolute value of the threshold voltage of NMOS and PMOS increased by about 10%, the saturation current of NMOS decreases by about 20%, while the saturation current of PMOS increases by about 20%. It is also found that the lower temperature enhances the STI stress and then influences the device performance further. Then a macro model for this effect is proposed and is well verified.
