To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D lea...To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D leader-following cooperative interception guidance law.First,in the LOS direction of the leader,an impact time-controlled guidance law is derived based on the fixed-time stability theory,which enables the leader to complete the interception task at a prespecified impact time.Next,in the LOS direction of the followers,by introducing a time consensus tracking error function,a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the time-to-go.Then,in the direction normal to the LOS,by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control(SMC)theory,an innovative 3D LOS-angle-constrained interception guidance law is developed,which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy consumption.Moreover,it effectively suppresses the chattering phenomenon while avoiding the singularity issue,and compensates for unknown interference caused by target maneuvering online,making it convenient for practical engineering applications.Finally,theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness,superiority,and robustness of the investigated guidance law.展开更多
Positional information plays a crucial role in embryonic pattern formation,yet its role in tooth development remains unexplored.In this study,we investigated the regional specification of lingual and buccal dental mes...Positional information plays a crucial role in embryonic pattern formation,yet its role in tooth development remains unexplored.In this study,we investigated the regional specification of lingual and buccal dental mesenchyme during tooth development.Tooth germs at the cap stage were dissected from mouse mandibles,and their lingual and buccal mesenchymal regions were separated for bulk RNA sequencing.Gene ontology analysis revealed that odontogenesis,pattern specification,and proliferation-related genes were enriched in the lingual mesenchyme,whereas stem cell development,mesenchymal differentiation,neural crest differentiation,and regeneration-related genes were predominant in the buccal mesenchyme.Reaggregation experiments using Wnt1^(cre ERT/+);R26R^(td T/+)and WT mouse models demonstrated that lingual mesenchyme contributes to tooth formation,while buccal mesenchyme primarily supports surrounding tissues.Furthermore,only the lingual part of tooth germs exhibited odontogenic potential when cultured in vitro and transplanted under the kidney capsule.Bulk RNA transcriptomic analysis further validated the regional specification of the lingual and buccal mesenchyme.These findings provide novel insights into the molecular basis of positional information in tooth development and pattern formation.展开更多
文摘To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D leader-following cooperative interception guidance law.First,in the LOS direction of the leader,an impact time-controlled guidance law is derived based on the fixed-time stability theory,which enables the leader to complete the interception task at a prespecified impact time.Next,in the LOS direction of the followers,by introducing a time consensus tracking error function,a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the time-to-go.Then,in the direction normal to the LOS,by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control(SMC)theory,an innovative 3D LOS-angle-constrained interception guidance law is developed,which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy consumption.Moreover,it effectively suppresses the chattering phenomenon while avoiding the singularity issue,and compensates for unknown interference caused by target maneuvering online,making it convenient for practical engineering applications.Finally,theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness,superiority,and robustness of the investigated guidance law.
基金The National Research Foundation of Korea(NRF)Grant funded by the Korea Government(MSIP)(RS-2024-00459728,RS-2025-00553972)supported this work。
文摘Positional information plays a crucial role in embryonic pattern formation,yet its role in tooth development remains unexplored.In this study,we investigated the regional specification of lingual and buccal dental mesenchyme during tooth development.Tooth germs at the cap stage were dissected from mouse mandibles,and their lingual and buccal mesenchymal regions were separated for bulk RNA sequencing.Gene ontology analysis revealed that odontogenesis,pattern specification,and proliferation-related genes were enriched in the lingual mesenchyme,whereas stem cell development,mesenchymal differentiation,neural crest differentiation,and regeneration-related genes were predominant in the buccal mesenchyme.Reaggregation experiments using Wnt1^(cre ERT/+);R26R^(td T/+)and WT mouse models demonstrated that lingual mesenchyme contributes to tooth formation,while buccal mesenchyme primarily supports surrounding tissues.Furthermore,only the lingual part of tooth germs exhibited odontogenic potential when cultured in vitro and transplanted under the kidney capsule.Bulk RNA transcriptomic analysis further validated the regional specification of the lingual and buccal mesenchyme.These findings provide novel insights into the molecular basis of positional information in tooth development and pattern formation.
