A new longitudinal attitude control system design for an unmanned seaplane in the severe sea states is presented in this paper. We develop a nonlinear passive observer, which is used to achieve wave filtering and stat...A new longitudinal attitude control system design for an unmanned seaplane in the severe sea states is presented in this paper. We develop a nonlinear passive observer, which is used to achieve wave filtering and state estimation. Moreover, the observer can be extended to achieve adaptive wave filtering in varying sea states. Using the estimated low-frequency states, a backstepping sliding mode controller is designed to keep the longitudinal attitude of the unmanned seaplane stable. The stability of the total closed loop system is analyzed by using Lyapunov theory. Simulations are performed in different wave conditions, including Seastate 3 and Seastate 5. The simulations results show that the proposed longitudinal attitude controller can improve the anti-waves capability effectively. Moreover, adaptive wave filter has a significant advantage over a filter with fixed model parameters in varying sea states.展开更多
Background Clinical guidelines recommend frailty screening for the aged population,given that frailty is frequently reversible.However,little is known about frailty and prefrailty reversal rates in the general populat...Background Clinical guidelines recommend frailty screening for the aged population,given that frailty is frequently reversible.However,little is known about frailty and prefrailty reversal rates in the general population if no specific interventions have been implemented.Aim To assess real-world frailty and prefrailty reversal rates in the general population aged≥65 years,the main contributing clinical conditions and the main risk factors for reversing frailty and prefrailty.Methods Observational longitudinal 12-month study(2019)of all 1·5 million persons aged≥65 years in Catalonia.Data were retrospectively collected from various health databases through the Catalan Public Data Analysis for Health Research and Innovation(PADRIS)V.2022 programme.Frailty status according to the electronic Screening Index for Frailty(e-SIF)was determined for 31 December 2018 and for 31 December 2019.Results The study included 1465312 Catalan inhabitants(mean age 75.8 years,57.0%women).The annual frailty and pre-frailty reversal rates were 7.1%and 4.6%,respectively.Both rates were higher in men and decreased with age.The e-SIF components with the greatest impact on frailty reversal were non-planned hospitalisations,polypharmacy,orthostatic hypotension or syncope,anaemia and visual impairment.Female sex,age,dependency,≥2 comorbidities and polypharmacy had an independent protective effect on 12-month frailty and pre-frailty reversals.Conclusions Prefrailty and frailty are reversible,but reversal is unlikely in cases of multimorbidity,polypharmacy and functional dependency in older and severely frail individuals.Interventions that mainly target the avoidance of non-planned hospitalisations,polypharmacy and falls would have the greatest impact on reversing frailty and pre-frailty.展开更多
We present an experimental study of multi-Raman gain resonances in a hot rubidium vapor.The experiment is performed based on a high-efficiency four-wave mixing process due to the Raman-driven coherence in a double-A c...We present an experimental study of multi-Raman gain resonances in a hot rubidium vapor.The experiment is performed based on a high-efficiency four-wave mixing process due to the Raman-driven coherence in a double-A configuration.The Raman gain resonance for ^（85）Rb atoms under a bias magnetic field is shown to be split into five or six peaks,depending on the orientation of the magnetic field.The formed multi-Raman gain resonances have potential applications in measurement of magnetic fields and generation of multi-frequency correlated twin beams.展开更多
Longitudinal data often occur in follow-up studies, and in many situations, there may exist informative observation times and a dependent terminal event such as death that stops the follow-up. We propose a semiparamet...Longitudinal data often occur in follow-up studies, and in many situations, there may exist informative observation times and a dependent terminal event such as death that stops the follow-up. We propose a semiparametric mixed effect model with time-varying latent effects in the analysis of longitudinal data with informative observation times and a dependent terminal event. Estimating equation approaches are developed for parameter estimation, and asymptotic properties of the resulting estimators are established. The finite sample behavior of the proposed estimators is evaluated through simulation studies, and an application to a bladder cancer study is provided.展开更多
We report experiments on the observation of the ^1S0-^3P0 transition spectrum of ^88Sr in the Lamb-Dicke regime.After going through a two-stage magneto-optical trap（MOT）,88 Sr cold atoms with number of about 1 ×...We report experiments on the observation of the ^1S0-^3P0 transition spectrum of ^88Sr in the Lamb-Dicke regime.After going through a two-stage magneto-optical trap（MOT）,88 Sr cold atoms with number of about 1 × 10^5 and a longitudinal temperature of 8.4 μK are loaded into a one-dimensional（1D） optical lattice, which is realized with a semiconductor laser at 813.4 nm. Using the magnetic field-inducing ^3P1 state mixing into ^3P0 state, the spectroscopy of the1S0-3P0 transition with a linewidth of 180 Hz is detected.展开更多
基金supported by National Natural Science Foundation of China(Nos.61273336,61203003,61273149 and 61421004)the Innovation Method Fund of China(No.2012IM010200)
文摘A new longitudinal attitude control system design for an unmanned seaplane in the severe sea states is presented in this paper. We develop a nonlinear passive observer, which is used to achieve wave filtering and state estimation. Moreover, the observer can be extended to achieve adaptive wave filtering in varying sea states. Using the estimated low-frequency states, a backstepping sliding mode controller is designed to keep the longitudinal attitude of the unmanned seaplane stable. The stability of the total closed loop system is analyzed by using Lyapunov theory. Simulations are performed in different wave conditions, including Seastate 3 and Seastate 5. The simulations results show that the proposed longitudinal attitude controller can improve the anti-waves capability effectively. Moreover, adaptive wave filter has a significant advantage over a filter with fixed model parameters in varying sea states.
基金Public Data Analysis for Health Research and Innovation(PADRIS)2022 programme of the Catalan Agency for Health Quality and Assessment(AQUAS,Catalan Government)(code P-762).
文摘Background Clinical guidelines recommend frailty screening for the aged population,given that frailty is frequently reversible.However,little is known about frailty and prefrailty reversal rates in the general population if no specific interventions have been implemented.Aim To assess real-world frailty and prefrailty reversal rates in the general population aged≥65 years,the main contributing clinical conditions and the main risk factors for reversing frailty and prefrailty.Methods Observational longitudinal 12-month study(2019)of all 1·5 million persons aged≥65 years in Catalonia.Data were retrospectively collected from various health databases through the Catalan Public Data Analysis for Health Research and Innovation(PADRIS)V.2022 programme.Frailty status according to the electronic Screening Index for Frailty(e-SIF)was determined for 31 December 2018 and for 31 December 2019.Results The study included 1465312 Catalan inhabitants(mean age 75.8 years,57.0%women).The annual frailty and pre-frailty reversal rates were 7.1%and 4.6%,respectively.Both rates were higher in men and decreased with age.The e-SIF components with the greatest impact on frailty reversal were non-planned hospitalisations,polypharmacy,orthostatic hypotension or syncope,anaemia and visual impairment.Female sex,age,dependency,≥2 comorbidities and polypharmacy had an independent protective effect on 12-month frailty and pre-frailty reversals.Conclusions Prefrailty and frailty are reversible,but reversal is unlikely in cases of multimorbidity,polypharmacy and functional dependency in older and severely frail individuals.Interventions that mainly target the avoidance of non-planned hospitalisations,polypharmacy and falls would have the greatest impact on reversing frailty and pre-frailty.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374238,11574247,and 11534008)the Fundamental Research Funds for the Central Universities,China(Grant No.xjj2014097)
文摘We present an experimental study of multi-Raman gain resonances in a hot rubidium vapor.The experiment is performed based on a high-efficiency four-wave mixing process due to the Raman-driven coherence in a double-A configuration.The Raman gain resonance for ^（85）Rb atoms under a bias magnetic field is shown to be split into five or six peaks,depending on the orientation of the magnetic field.The formed multi-Raman gain resonances have potential applications in measurement of magnetic fields and generation of multi-frequency correlated twin beams.
基金supported by National Natural Science Foundation of China (Grant Nos. 11231010, 11171330 and 11201315)Key Laboratory of Random Complex Structures and Data Science, Chinese Academy of Sciences (Grant No. 2008DP173182)Beijing Center for Mathematics and Information Interdisciplinary Sciences
文摘Longitudinal data often occur in follow-up studies, and in many situations, there may exist informative observation times and a dependent terminal event such as death that stops the follow-up. We propose a semiparametric mixed effect model with time-varying latent effects in the analysis of longitudinal data with informative observation times and a dependent terminal event. Estimating equation approaches are developed for parameter estimation, and asymptotic properties of the resulting estimators are established. The finite sample behavior of the proposed estimators is evaluated through simulation studies, and an application to a bladder cancer study is provided.
基金supported by the National Nature Science Foundation of China (Nos. 61127901 and 11474282)the Key Project of the Chinese Academy of Sciences (No. KJZD-EW-W02)
文摘We report experiments on the observation of the ^1S0-^3P0 transition spectrum of ^88Sr in the Lamb-Dicke regime.After going through a two-stage magneto-optical trap（MOT）,88 Sr cold atoms with number of about 1 × 10^5 and a longitudinal temperature of 8.4 μK are loaded into a one-dimensional（1D） optical lattice, which is realized with a semiconductor laser at 813.4 nm. Using the magnetic field-inducing ^3P1 state mixing into ^3P0 state, the spectroscopy of the1S0-3P0 transition with a linewidth of 180 Hz is detected.
