This paper studies the moving path following(MPF)problem for fixed-wing unmanned aerial vehicle(UAV)under output constraints and wind disturbances.The vehicle is required to converge to a reference path moving with re...This paper studies the moving path following(MPF)problem for fixed-wing unmanned aerial vehicle(UAV)under output constraints and wind disturbances.The vehicle is required to converge to a reference path moving with respect to the inertial frame,while the path following error is not expected to violate the predefined boundaries.Differently from existing moving path following guidance laws,the proposed method removes complex geometric transformation by formulating the moving path following problem into a second-order time-varying control problem.A nominal moving path following guidance law is designed with disturbances and their derivatives estimated by high-order disturbance observers.To guarantee that the path following error will not exceed the prescribed bounds,a robust control barrier function is developed and incorporated into controller design with quadratic program based framework.The proposed method does not require the initial position of the UAV to be within predefined boundaries.And the safety margin concept makes error-constraint be respected even if in a noisy environment.The proposed guidance law is validated through numerical simulations of shipboard landing and hardware-in-theloop(HIL)experiments.展开更多
AIM: To determine the mortality associated with functional bowel disorders (FBDs) and their possible relationship with organic bowel disease. METHODS: Patients who satisfied the Rome Ⅲ criteria for FBD (retrospective...AIM: To determine the mortality associated with functional bowel disorders (FBDs) and their possible relationship with organic bowel disease. METHODS: Patients who satisfied the Rome Ⅲ criteria for FBD (retrospective diagnosis) were followed up by telephone interview and/or outpatient review at 5 years after their first attendance. The patients were divided into the following groups: irritable bowel syndrome, functional abdominal bloating, functional constipation, functional diarrhea and unspecified FBD. The survival of the FBD patients overall and of those with each FBD were compared with data obtained from the Guangzhou population in 2005. The incidences of colonic cancer overall and for each FBD were compared with data from the Chinese population obtained from 56 cancer registries in 19 provinces of the country in 2008. RESULTS: Two hundred and sixty-three patients were followed-up. Five patients died, which was not significantly different from the expected survival rate. No differences in mortality among the FBDs were found. There were nine cases of organic bowel disease: three colonic cancers and six colonic polyps. The incidence of colonic cancer in FBD patients was higher than that in the general Chinese population (0.23% vs 0.03%, P < 0.05). There were significant differences in the incidence of colonic cancer among the FBDs (0/134, 0/24, 2/29, 1/66, 0/10, respectively, P<0.05); functional constipation was the most common. The incidence of colonic polyps was similar among the FBDs. The baseline age of patients who died was greater than that of those who survived (66.60±6.84 years vs 45.14±10.34 years, P<0.05). The baseline age of patients who had colonic cancer or polyps during follow-up was greater than that of those without colonic cancer or polyps (60.33±1.53 years vs 45.38±10.62 years; 54.50±6.47 years vs 45.34±10.68 years, P<0.05). CONCLUSION: FBDs do not increase the risk of death. The incidence of colonic cancer in patients with FBDs may be increased, especially in those with functional constipation and in the elderly.展开更多
Totally three articles focusing on functional magnetic resonance imaging features of brain function in the activated brain regions of stroke patients undergoing acupuncture on the healthy limbs and healthy controls un...Totally three articles focusing on functional magnetic resonance imaging features of brain function in the activated brain regions of stroke patients undergoing acupuncture on the healthy limbs and healthy controls undergoing acupuncture on the lower extremities are published in three issues. We hope that our readers find these papers useful to their research.展开更多
基金supported in part by the National Natural Science Foundations of China(62173016,62073019)the Fundamental Research Funds for the Central Universities(YWF-23-JC-04,YWF-23-JC-02)。
文摘This paper studies the moving path following(MPF)problem for fixed-wing unmanned aerial vehicle(UAV)under output constraints and wind disturbances.The vehicle is required to converge to a reference path moving with respect to the inertial frame,while the path following error is not expected to violate the predefined boundaries.Differently from existing moving path following guidance laws,the proposed method removes complex geometric transformation by formulating the moving path following problem into a second-order time-varying control problem.A nominal moving path following guidance law is designed with disturbances and their derivatives estimated by high-order disturbance observers.To guarantee that the path following error will not exceed the prescribed bounds,a robust control barrier function is developed and incorporated into controller design with quadratic program based framework.The proposed method does not require the initial position of the UAV to be within predefined boundaries.And the safety margin concept makes error-constraint be respected even if in a noisy environment.The proposed guidance law is validated through numerical simulations of shipboard landing and hardware-in-theloop(HIL)experiments.
基金Supported by The Open Project Program of the Jiangsu Key Laboratory of Molecular and Functional Imaging, No. PYZX2011016the Medical Science and Technology Development Foundation of Nanjing Department of Health, No.YKK11199
文摘AIM: To determine the mortality associated with functional bowel disorders (FBDs) and their possible relationship with organic bowel disease. METHODS: Patients who satisfied the Rome Ⅲ criteria for FBD (retrospective diagnosis) were followed up by telephone interview and/or outpatient review at 5 years after their first attendance. The patients were divided into the following groups: irritable bowel syndrome, functional abdominal bloating, functional constipation, functional diarrhea and unspecified FBD. The survival of the FBD patients overall and of those with each FBD were compared with data obtained from the Guangzhou population in 2005. The incidences of colonic cancer overall and for each FBD were compared with data from the Chinese population obtained from 56 cancer registries in 19 provinces of the country in 2008. RESULTS: Two hundred and sixty-three patients were followed-up. Five patients died, which was not significantly different from the expected survival rate. No differences in mortality among the FBDs were found. There were nine cases of organic bowel disease: three colonic cancers and six colonic polyps. The incidence of colonic cancer in FBD patients was higher than that in the general Chinese population (0.23% vs 0.03%, P < 0.05). There were significant differences in the incidence of colonic cancer among the FBDs (0/134, 0/24, 2/29, 1/66, 0/10, respectively, P<0.05); functional constipation was the most common. The incidence of colonic polyps was similar among the FBDs. The baseline age of patients who died was greater than that of those who survived (66.60±6.84 years vs 45.14±10.34 years, P<0.05). The baseline age of patients who had colonic cancer or polyps during follow-up was greater than that of those without colonic cancer or polyps (60.33±1.53 years vs 45.38±10.62 years; 54.50±6.47 years vs 45.34±10.68 years, P<0.05). CONCLUSION: FBDs do not increase the risk of death. The incidence of colonic cancer in patients with FBDs may be increased, especially in those with functional constipation and in the elderly.
文摘Totally three articles focusing on functional magnetic resonance imaging features of brain function in the activated brain regions of stroke patients undergoing acupuncture on the healthy limbs and healthy controls undergoing acupuncture on the lower extremities are published in three issues. We hope that our readers find these papers useful to their research.
