The state estimation strategy using the smooth variable structure filter （SVSF） is based on the variable structure and sliding mode concepts. As presented in its standard form with a fixed boundary layer limit, the ...The state estimation strategy using the smooth variable structure filter （SVSF） is based on the variable structure and sliding mode concepts. As presented in its standard form with a fixed boundary layer limit, the value of the boundary layer width is not precisely known at each step and may be selected based on a priori knowledge. The boundary layer width reflects the level of uncertainty in the model parameters and disturbance characteristics, where large values of the boundary layer width lead to robustness without optimality and small values of the boundary layer width provide optimality with poor robustness. As a solution and to overcome these limitations, an adaptive smoothing boundary layer is required to achieve greater robustness and suitable accuracy. This adapted value of the boundary layer width is obtained by minimizing the trace of the a posteriori covariance matrix. In this paper, the proposed new approach will be considered as another alternative to the extended Kalman filters （EKF）, nonlinear H∞ and standard SVSF-based data fusion techniques for the autonomous airborne navigation and self-localization problem. This alternative is based on strapdown inertial navigation system （SINS） and GPS data using the nonlinear SVSF with a covariance derivation and adaptive boundary layer width. Furthermore, the full mathematical model of the SINS/GPS navigation system considering the unmanned aerial vehicle （UAV） position, velocity and Euler angle as well as gyro and accelerometer biases will be used in this paper to estimate the airborne position and velocity with better accuracy.展开更多
The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an L...The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an LCVR polarimeter,an image-stabilization system,a seven-stage tunable Lyot filter,a CMOS camera with 4096×4096 pixels and a pair of calibration/focus wheels.In this paper,we describe the design of the FMG instrument and provide a summary of test observations carried out with the FMG prototype.展开更多
The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the...The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.展开更多
The high-temperature reactor pebble-bed mod-ule(HTR-PM)is a modular high-temperature gas-cooled reactor demonstration power plant.Its first criticality experiment is scheduled for the latter half of 2021.Before perfor...The high-temperature reactor pebble-bed mod-ule(HTR-PM)is a modular high-temperature gas-cooled reactor demonstration power plant.Its first criticality experiment is scheduled for the latter half of 2021.Before performing the first criticality experiment,a prediction calculation was performed using PANGU code.This paper presents the calculation details for predicting the HTR-PM first criticality using PANGU,including the input model and parameters,numerical results,and uncertainty analysis.The accuracy of the PANGU code was demonstrated by comparing it with the high-fidelity Monte Carlo solution,using the same input configurations.It should be noted that k eff can be significantly affected by uncertainties in nuclear data and certain input parameters,making the criticality calculation challenge.Finally,the PANGU is used to pre-dict the critical loading height of the HTR-PM first criti-cality under design conditions,which will be evaluated in the upcoming experiment later this year.展开更多
This paper proposed a semi-supervised regression model with co-training algorithm based on support vector machine, which was used for retrieving water quality variables from SPOT 5 remote sensing data. The model consi...This paper proposed a semi-supervised regression model with co-training algorithm based on support vector machine, which was used for retrieving water quality variables from SPOT 5 remote sensing data. The model consisted of two support vector regressors (SVRs). Nonlinear relationship between water quality variables and SPOT 5 spectrum was described by the two SVRs, and semi-supervised co-training algorithm for the SVRs was es-tablished. The model was used for retrieving concentrations of four representative pollution indicators―permangan- ate index (CODmn), ammonia nitrogen (NH3-N), chemical oxygen demand (COD) and dissolved oxygen (DO) of the Weihe River in Shaanxi Province, China. The spatial distribution map for those variables over a part of the Weihe River was also produced. SVR can be used to implement any nonlinear mapping readily, and semi-supervis- ed learning can make use of both labeled and unlabeled samples. By integrating the two SVRs and using semi-supervised learning, we provide an operational method when paired samples are limited. The results show that it is much better than the multiple statistical regression method, and can provide the whole water pollution condi-tions for management fast and can be extended to hyperspectral remote sensing applications.展开更多
Pod shatter resistance of rapeseed is of great importance for modem farming practice. In order to determine the combining ability of elite inbred lines and the breeding potential of rapeseed hybrids in terms of pod sh...Pod shatter resistance of rapeseed is of great importance for modem farming practice. In order to determine the combining ability of elite inbred lines and the breeding potential of rapeseed hybrids in terms of pod shatter resistance, analysis of a 6×6 incomplete diallel cross was conducted at two locations. Results showed that a significant variation existed among breeding lines and their F1 hybrids for pod shatter resistant index （SRI）, pod length and width. Pod shatter resistance was significantly positively correlated with pod length. The general combining ability （GCA） effects （GCA=l.58） played a more important role than specific combining ability （SCA） effects （SCA=0.20） for pod shatter trait. The elite lines R1, 1019B and 1055B displayed significant positive GCA effects for pod shatter resistance. Four crosses （1019B×R1, 1015B×R1, 6098B×R1, and 8908B×R1） with high mean performance and positive SCA effects were recommended for developing new hybrids for mechanical harvest in the middle reaches of the Yangtze River.展开更多
基金supported by the National Natural Science Foundation of China(No.61375082)
文摘The state estimation strategy using the smooth variable structure filter （SVSF） is based on the variable structure and sliding mode concepts. As presented in its standard form with a fixed boundary layer limit, the value of the boundary layer width is not precisely known at each step and may be selected based on a priori knowledge. The boundary layer width reflects the level of uncertainty in the model parameters and disturbance characteristics, where large values of the boundary layer width lead to robustness without optimality and small values of the boundary layer width provide optimality with poor robustness. As a solution and to overcome these limitations, an adaptive smoothing boundary layer is required to achieve greater robustness and suitable accuracy. This adapted value of the boundary layer width is obtained by minimizing the trace of the a posteriori covariance matrix. In this paper, the proposed new approach will be considered as another alternative to the extended Kalman filters （EKF）, nonlinear H∞ and standard SVSF-based data fusion techniques for the autonomous airborne navigation and self-localization problem. This alternative is based on strapdown inertial navigation system （SINS） and GPS data using the nonlinear SVSF with a covariance derivation and adaptive boundary layer width. Furthermore, the full mathematical model of the SINS/GPS navigation system considering the unmanned aerial vehicle （UAV） position, velocity and Euler angle as well as gyro and accelerometer biases will be used in this paper to estimate the airborne position and velocity with better accuracy.
基金China Aerospace Science and Technology Corporation, the NO.771 InstituteChina Academy of Engineering Physics+4 种基金Changchun Institute of Optics, Fine Mechanics and Physics, CASNational Space Science Center, CASShanghai Engineering Center for Microsatellites, CASPurple Mountain Observatory, CASsupported by Grants:XDA15320102, 11427901 and XDA15052200
文摘The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an LCVR polarimeter,an image-stabilization system,a seven-stage tunable Lyot filter,a CMOS camera with 4096×4096 pixels and a pair of calibration/focus wheels.In this paper,we describe the design of the FMG instrument and provide a summary of test observations carried out with the FMG prototype.
基金supported by the National Natural Science Foundation of China(NSFC)under Grants 11825301,12003016,12073077the National Key R&D Program of China No.2021YFA0718600+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences with the Grant No.XDA15018400the Youth Innovation Promotion Association of CAS(2023061)。
文摘The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections.
基金supported by the National S&T Major Project of China(Nos.ZX0690,ZX06902)the CNNC Youth Research Project.
文摘The high-temperature reactor pebble-bed mod-ule(HTR-PM)is a modular high-temperature gas-cooled reactor demonstration power plant.Its first criticality experiment is scheduled for the latter half of 2021.Before performing the first criticality experiment,a prediction calculation was performed using PANGU code.This paper presents the calculation details for predicting the HTR-PM first criticality using PANGU,including the input model and parameters,numerical results,and uncertainty analysis.The accuracy of the PANGU code was demonstrated by comparing it with the high-fidelity Monte Carlo solution,using the same input configurations.It should be noted that k eff can be significantly affected by uncertainties in nuclear data and certain input parameters,making the criticality calculation challenge.Finally,the PANGU is used to pre-dict the critical loading height of the HTR-PM first criti-cality under design conditions,which will be evaluated in the upcoming experiment later this year.
基金Under the auspices of National Natural Science Foundation of China (No. 40671133)Fundamental Research Funds for the Central Universities (No. GK200902015)
文摘This paper proposed a semi-supervised regression model with co-training algorithm based on support vector machine, which was used for retrieving water quality variables from SPOT 5 remote sensing data. The model consisted of two support vector regressors (SVRs). Nonlinear relationship between water quality variables and SPOT 5 spectrum was described by the two SVRs, and semi-supervised co-training algorithm for the SVRs was es-tablished. The model was used for retrieving concentrations of four representative pollution indicators―permangan- ate index (CODmn), ammonia nitrogen (NH3-N), chemical oxygen demand (COD) and dissolved oxygen (DO) of the Weihe River in Shaanxi Province, China. The spatial distribution map for those variables over a part of the Weihe River was also produced. SVR can be used to implement any nonlinear mapping readily, and semi-supervis- ed learning can make use of both labeled and unlabeled samples. By integrating the two SVRs and using semi-supervised learning, we provide an operational method when paired samples are limited. The results show that it is much better than the multiple statistical regression method, and can provide the whole water pollution condi-tions for management fast and can be extended to hyperspectral remote sensing applications.
基金supported by the National Basic Research Program of China (973 Program, 2011CB109302)the National High-Tech R&D Program of China (863 Program,2011AA10A104)the earmarked fund for China Agriculture Research System (CARS-13)
文摘Pod shatter resistance of rapeseed is of great importance for modem farming practice. In order to determine the combining ability of elite inbred lines and the breeding potential of rapeseed hybrids in terms of pod shatter resistance, analysis of a 6×6 incomplete diallel cross was conducted at two locations. Results showed that a significant variation existed among breeding lines and their F1 hybrids for pod shatter resistant index （SRI）, pod length and width. Pod shatter resistance was significantly positively correlated with pod length. The general combining ability （GCA） effects （GCA=l.58） played a more important role than specific combining ability （SCA） effects （SCA=0.20） for pod shatter trait. The elite lines R1, 1019B and 1055B displayed significant positive GCA effects for pod shatter resistance. Four crosses （1019B×R1, 1015B×R1, 6098B×R1, and 8908B×R1） with high mean performance and positive SCA effects were recommended for developing new hybrids for mechanical harvest in the middle reaches of the Yangtze River.
