To evaluate the heat performance of the lifting-body entry vehicle during the hypersonic gliding phase,entry flight heat tests involving the determination of the maximum peak-heat-flux entry trajectory with complex co...To evaluate the heat performance of the lifting-body entry vehicle during the hypersonic gliding phase,entry flight heat tests involving the determination of the maximum peak-heat-flux entry trajectory with complex constraints are essential.A significant obstacle is the uncertainty of passage time or energy states of the maximum peak entry heat flux point and waypoints.This paper showcases an endeavour to leverage disjunctive programming and combinatorial theory for the max-max type(maximum peak-heat-flux)Entry Trajectory Optimization(ETO)problems with complex constraints such as dynamic pressure,normal load,waypoints,and no-fly zones.The concept of a"generalized waypoint"is introduced,and the maximum peak-heat-flux point is regarded as a"generalized waypoint".Through the application of propositional calculus rules,the derivation of generalized waypoints incorporating various physical quantities and magnitudes such as heat flux density,longitude,and latitude is actualized in one disjunctive normal form,enabling resolution via a unified method.Consequently,a novel method based on combinatorial prior rules is proposed,utilizing Successive Mixed-Integer Nonlinear Programming(SMINLP)to optimize various heat entry test flight trajectories.Numerical experiments are provided to show the computational accuracy,stability,and adaptability of the proposed method in solving maxmax type entry optimal control problems.展开更多
This paper describes a new method of small moving target detection and analyzes the performance of this algorithm. The method is based on multi-level threshold decision-making and sliding trajectory confidence testing...This paper describes a new method of small moving target detection and analyzes the performance of this algorithm. The method is based on multi-level threshold decision-making and sliding trajectory confidence testing technology. The parameters of the algorithm are also given. Experiments have been conducted, the results show that the algorithm has advantages of high detection probability, simple structure, and excellent real-time performance.展开更多
BACKGROUND Cerebral infarction is a local or extensive necrosis of brain tissue.Subsequently,the corresponding neurological deficits appear.The incidence of cerebrovascular diseases in China is increasing gradually.Af...BACKGROUND Cerebral infarction is a local or extensive necrosis of brain tissue.Subsequently,the corresponding neurological deficits appear.The incidence of cerebrovascular diseases in China is increasing gradually.After the onset of cerebrovascular disease,the most common sequelae include movement disorders,language disorders,and cognitive dysfunction.AIM To investigate the effect of early refined nursing program on the prognosis of middle-aged and elderly patients with cerebral infarction combined with cognitive dysfunction.METHODS A retrospective study was conducted to divide 60 patients with cerebral infarction and cognitive impairment into an experimental group(n=32)and a control group(n=28).The experimental group received early intensive care every day,and the control group received daily routine care.The scores of the Mini-Mental State Examination(MMSE)and the Trail Making Test(TMT),as well as the latency and amplitude of the event-related potential P300,were used as main indicators to evaluate changes in cognitive function,and changes in BDNF,TGF-β,and GDNF expression were used as secondary indicators.RESULTS Both groups experienced notable enhancements in MMSE scores,with the experi-mental group demonstrating higher scores than the control group(experimental:28.75±2.31;control:25.84±2.87).Moreover,reductions in TMT-A and TMT-B scores were observed in both groups(experimental:TMT-A 52.36±6.18,TMT-B 98.47±10.23;control:TMT-A 61.48±7.92,TMT-B 112.63±12.55),with the experimental group displaying lower scores.P300 Latency decreased(experimental:270.63 ms±14.28 ms;control:285.72 ms±16.45 ms),while amplitude increased(experimental:7.82μV±1.05μV;control:6.35μV±0.98μV)significantly in both groups,with superior outcomes in the experimental cohort.Additionally,the levels of the growth factors BDNF,TGF-β1,and GDNF surged(experimental:BDNF 48.37 ng/mL±5.62 ng/mL,TGF-β152.14 pg/mL±4.28 pg/mL,GDNF 34.76 ng/mL±3.89 ng/mL;control:BDNF 42.58 ng/mL±4.73 ng/mL,TGF-β146.23 pg/mL±3.94 pg/mL,GDNF 30.25 ng/mL±2.98 ng/mL)in both groups,with higher levels in the experimental group.CONCLUSION For middle-aged and elderly patients with cerebral infarction and cognitive dysfunction,early refined nursing can significantly improve their cognitive function and prognosis.展开更多
基金funded by the Key Laboratory of Cross-Domain Flight Interdisciplinary Technology,China(No.2024-KF02201)the National Natural Science Foundation of China(No.61973326)。
文摘To evaluate the heat performance of the lifting-body entry vehicle during the hypersonic gliding phase,entry flight heat tests involving the determination of the maximum peak-heat-flux entry trajectory with complex constraints are essential.A significant obstacle is the uncertainty of passage time or energy states of the maximum peak entry heat flux point and waypoints.This paper showcases an endeavour to leverage disjunctive programming and combinatorial theory for the max-max type(maximum peak-heat-flux)Entry Trajectory Optimization(ETO)problems with complex constraints such as dynamic pressure,normal load,waypoints,and no-fly zones.The concept of a"generalized waypoint"is introduced,and the maximum peak-heat-flux point is regarded as a"generalized waypoint".Through the application of propositional calculus rules,the derivation of generalized waypoints incorporating various physical quantities and magnitudes such as heat flux density,longitude,and latitude is actualized in one disjunctive normal form,enabling resolution via a unified method.Consequently,a novel method based on combinatorial prior rules is proposed,utilizing Successive Mixed-Integer Nonlinear Programming(SMINLP)to optimize various heat entry test flight trajectories.Numerical experiments are provided to show the computational accuracy,stability,and adaptability of the proposed method in solving maxmax type entry optimal control problems.
文摘This paper describes a new method of small moving target detection and analyzes the performance of this algorithm. The method is based on multi-level threshold decision-making and sliding trajectory confidence testing technology. The parameters of the algorithm are also given. Experiments have been conducted, the results show that the algorithm has advantages of high detection probability, simple structure, and excellent real-time performance.
文摘BACKGROUND Cerebral infarction is a local or extensive necrosis of brain tissue.Subsequently,the corresponding neurological deficits appear.The incidence of cerebrovascular diseases in China is increasing gradually.After the onset of cerebrovascular disease,the most common sequelae include movement disorders,language disorders,and cognitive dysfunction.AIM To investigate the effect of early refined nursing program on the prognosis of middle-aged and elderly patients with cerebral infarction combined with cognitive dysfunction.METHODS A retrospective study was conducted to divide 60 patients with cerebral infarction and cognitive impairment into an experimental group(n=32)and a control group(n=28).The experimental group received early intensive care every day,and the control group received daily routine care.The scores of the Mini-Mental State Examination(MMSE)and the Trail Making Test(TMT),as well as the latency and amplitude of the event-related potential P300,were used as main indicators to evaluate changes in cognitive function,and changes in BDNF,TGF-β,and GDNF expression were used as secondary indicators.RESULTS Both groups experienced notable enhancements in MMSE scores,with the experi-mental group demonstrating higher scores than the control group(experimental:28.75±2.31;control:25.84±2.87).Moreover,reductions in TMT-A and TMT-B scores were observed in both groups(experimental:TMT-A 52.36±6.18,TMT-B 98.47±10.23;control:TMT-A 61.48±7.92,TMT-B 112.63±12.55),with the experimental group displaying lower scores.P300 Latency decreased(experimental:270.63 ms±14.28 ms;control:285.72 ms±16.45 ms),while amplitude increased(experimental:7.82μV±1.05μV;control:6.35μV±0.98μV)significantly in both groups,with superior outcomes in the experimental cohort.Additionally,the levels of the growth factors BDNF,TGF-β1,and GDNF surged(experimental:BDNF 48.37 ng/mL±5.62 ng/mL,TGF-β152.14 pg/mL±4.28 pg/mL,GDNF 34.76 ng/mL±3.89 ng/mL;control:BDNF 42.58 ng/mL±4.73 ng/mL,TGF-β146.23 pg/mL±3.94 pg/mL,GDNF 30.25 ng/mL±2.98 ng/mL)in both groups,with higher levels in the experimental group.CONCLUSION For middle-aged and elderly patients with cerebral infarction and cognitive dysfunction,early refined nursing can significantly improve their cognitive function and prognosis.
