A new type of guidance strategy, combining linear quadratic and norm-bounded game theory, is proposed for the scenario of an attacker against active defense aircraft in three-player engagement. The problem involves th...A new type of guidance strategy, combining linear quadratic and norm-bounded game theory, is proposed for the scenario of an attacker against active defense aircraft in three-player engagement. The problem involves three players, an attacker, a defender and a target. The differential game theory and the solution of Hamiltonian equation are utilized to obtain the combined guidance strategy for each player with arbitrary-order dynamics. The game process is divided into4 phases, C1-C4, according to the switching time. The linear quadratic differential game guidance scheme is employed to reduce the fuel cost in the game parts of C1 and C3. The norm-bounded game guidance strategy is adopted to satisfy the constraint of control input in the game stages C2 and C4. Furthermore, zero-effort miss distance is introduced to meet the constraints of game space and defender’s killing radius in the guidance strategy, which guarantees that the attacker is able to avoid the interception of the defender and hit the target with lower fuel cost and maximum acceleration. And it is proved that the proposed guidance strategy satisfies the Nash equilibrium condition. Finally, the feasibility and superiority of combined guidance strategy are respectively illustrated by nonlinear numerical simulation and verified by comparing with linear quadratic and norm-bounded differential game guidance strategies.展开更多
Southern corn rust(SCR),caused by the fungal pathogen Puccinia polysora,is a major threat to maize pro-duction worldwide.Efficient breeding and deployment of resistant hybrids are key to achieving durable control of S...Southern corn rust(SCR),caused by the fungal pathogen Puccinia polysora,is a major threat to maize pro-duction worldwide.Efficient breeding and deployment of resistant hybrids are key to achieving durable control of SCR.Here,we report the molecular cloning and characterization of RppC,which encodes an NLR-type immune receptor and is responsible for a major SCR resistance quantitative trait locus.Further-more,we identified the corresponding avirulence effector,AvrRppC,which is secreted by P.polysora and triggers RppC-mediated resistance.Allelic variation of AvrRppC directly determines the effectiveness of RppC-mediated resistance,indicating that monitoring of AvrRppC variants in the field can guide the rational deployment of RppC-containing hybrids in maize production.Currently,RppC is the most frequently deployed SCR resistance gene in China,and a better understanding of its mode of action is crit-ical for extending its durability.展开更多
Video colorization is a challenging and highly ill-posed problem.Although recent years have witnessed remarkable progress in single image colorization,there is relatively less research effort on video colorization,and...Video colorization is a challenging and highly ill-posed problem.Although recent years have witnessed remarkable progress in single image colorization,there is relatively less research effort on video colorization,and existing methods always suffer from severe flickering artifacts(temporal inconsistency)or unsatisfactory colorization.We address this problem from a new perspective,by jointly considering colorization and temporal consistency in a unified framework.Specifically,we propose a novel temporally consistent video colorization(TCVC)framework.TCVC effectively propagates frame-level deep features in a bidirectional way to enhance the temporal consistency of colorization.Furthermore,TCVC introduces a self-regularization learning(SRL)scheme to minimize the differences in predictions obtained using different time steps.SRL does not require any ground-truth color videos for training and can further improve temporal consistency.Experiments demonstrate that our method can not only provide visually pleasing colorized video,but also with clearly better temporal consistency than state-of-the-art methods.A video demo is provided at https://www.youtube.com/watch?v=c7dczMs-olE,while code is available at https://github.com/lyh-18/TCVC-Tem porally-Consistent-Video-Colorization.展开更多
基金supported by the National Natural Science Foundation of China(Nos.62273119 and 61627810).
文摘A new type of guidance strategy, combining linear quadratic and norm-bounded game theory, is proposed for the scenario of an attacker against active defense aircraft in three-player engagement. The problem involves three players, an attacker, a defender and a target. The differential game theory and the solution of Hamiltonian equation are utilized to obtain the combined guidance strategy for each player with arbitrary-order dynamics. The game process is divided into4 phases, C1-C4, according to the switching time. The linear quadratic differential game guidance scheme is employed to reduce the fuel cost in the game parts of C1 and C3. The norm-bounded game guidance strategy is adopted to satisfy the constraint of control input in the game stages C2 and C4. Furthermore, zero-effort miss distance is introduced to meet the constraints of game space and defender’s killing radius in the guidance strategy, which guarantees that the attacker is able to avoid the interception of the defender and hit the target with lower fuel cost and maximum acceleration. And it is proved that the proposed guidance strategy satisfies the Nash equilibrium condition. Finally, the feasibility and superiority of combined guidance strategy are respectively illustrated by nonlinear numerical simulation and verified by comparing with linear quadratic and norm-bounded differential game guidance strategies.
基金supported by grants from the National Key Research and Development Program of China(2021YFF1000302)the National Natural Science Foundation of China(31901550)+2 种基金the Ministry of Science and Technology of China(2016YFD0101803)the National Natural Science Foundation of China(31501326)Innovative Talents in Colleges and Universities of Henan Province(19HASTIT010)was a funding pro-vided by Henan Province government of China.
文摘Southern corn rust(SCR),caused by the fungal pathogen Puccinia polysora,is a major threat to maize pro-duction worldwide.Efficient breeding and deployment of resistant hybrids are key to achieving durable control of SCR.Here,we report the molecular cloning and characterization of RppC,which encodes an NLR-type immune receptor and is responsible for a major SCR resistance quantitative trait locus.Further-more,we identified the corresponding avirulence effector,AvrRppC,which is secreted by P.polysora and triggers RppC-mediated resistance.Allelic variation of AvrRppC directly determines the effectiveness of RppC-mediated resistance,indicating that monitoring of AvrRppC variants in the field can guide the rational deployment of RppC-containing hybrids in maize production.Currently,RppC is the most frequently deployed SCR resistance gene in China,and a better understanding of its mode of action is crit-ical for extending its durability.
基金supported by grants from the National Natural Science Foundation of China(61906184)the Joint Lab of CAS–HK,and the Shanghai Committee of Science and Technology,China(20DZ1100800,21DZ1100100).
文摘Video colorization is a challenging and highly ill-posed problem.Although recent years have witnessed remarkable progress in single image colorization,there is relatively less research effort on video colorization,and existing methods always suffer from severe flickering artifacts(temporal inconsistency)or unsatisfactory colorization.We address this problem from a new perspective,by jointly considering colorization and temporal consistency in a unified framework.Specifically,we propose a novel temporally consistent video colorization(TCVC)framework.TCVC effectively propagates frame-level deep features in a bidirectional way to enhance the temporal consistency of colorization.Furthermore,TCVC introduces a self-regularization learning(SRL)scheme to minimize the differences in predictions obtained using different time steps.SRL does not require any ground-truth color videos for training and can further improve temporal consistency.Experiments demonstrate that our method can not only provide visually pleasing colorized video,but also with clearly better temporal consistency than state-of-the-art methods.A video demo is provided at https://www.youtube.com/watch?v=c7dczMs-olE,while code is available at https://github.com/lyh-18/TCVC-Tem porally-Consistent-Video-Colorization.
