We study the global dynamics of a rational diference equation with higher order,which includes many rational diference equations as its special cases.By some complicate computations and mathematical skills,we show tha...We study the global dynamics of a rational diference equation with higher order,which includes many rational diference equations as its special cases.By some complicate computations and mathematical skills,we show that its unique nonnegative fixed point is globally attractive.As application,our results not only improve many known ones,but also solve several“Open Problems and Conjectures”given by Professors Ladas and Camouzis,et al.展开更多
针对工业装配任务,尤其是不规则轴孔工件装配中,基于学习的前期样本质量低、训练过程不稳定等问题,提出一种融合引斥力模型(Attraction-Repulsion Model,ARM)引导机制和长短期记忆网络(Long Short Term Memory,LSTM)的柔性演员-评论家(S...针对工业装配任务,尤其是不规则轴孔工件装配中,基于学习的前期样本质量低、训练过程不稳定等问题,提出一种融合引斥力模型(Attraction-Repulsion Model,ARM)引导机制和长短期记忆网络(Long Short Term Memory,LSTM)的柔性演员-评论家(Soft Actor-Critic,SAC)算法。首先,为解决训练初期探索效率低的问题,提出一种基于引斥力模型的策略引导机制,通过目标位置信息引导机械臂运动,加速收敛过程;其次,基于长短期记忆网络对算法的策略网络和价值网络进行改进,有效利用历史信息,增强策略学习能力,提高算法的收敛速度和稳定性。仿真结果表明,所提出的算法在行星减速器中心轴装配任务中取得显著的效果,装配成功率高达99.4%,与普通SAC算法相比,平均最大接触力和力矩分别降低了68.8%和79.2%。在物理环境中装配成功率达95%以上,最大接触力和力矩分别小于10 N和1.5 N·m,验证了算法的有效性。展开更多
Consider the discrete Lasota Wazewska modelN n+1 -N n =-μN n +pe -rN n-k , n=0,1,2,...(*)where μ∈(0,1),r,p∈(0,∞) and k ∈N.A sufficient condition for all positive solutions of (*) to...Consider the discrete Lasota Wazewska modelN n+1 -N n =-μN n +pe -rN n-k , n=0,1,2,...(*)where μ∈(0,1),r,p∈(0,∞) and k ∈N.A sufficient condition for all positive solutions of (*) to be attracted to its equilibrium N is obtained.It improves correspondent result obtained by Chen and Yu in 1999.展开更多
The existence of positive solutions and the global attractivity of the difference equation Δy n=r ny nK-y n-l n K-cy n-l n are investigated. And some sufficient conditions are obtained,which greatly imp...The existence of positive solutions and the global attractivity of the difference equation Δy n=r ny nK-y n-l n K-cy n-l n are investigated. And some sufficient conditions are obtained,which greatly improve and extend the known results.展开更多
Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjectur...Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.展开更多
A population of interacting species is considered which is governed by a system of nonlinear difference equation.In the case of the interacting species with competition,a sufficient condition for global attractivity o...A population of interacting species is considered which is governed by a system of nonlinear difference equation.In the case of the interacting species with competition,a sufficient condition for global attractivity of an equilibrium state is derived.The result can be considered as a best discrete approximation of the continuous system.展开更多
In this paper, the qualitative properties of general nonautonomous Lotka-Volterran-species competitive systems with impulsive e？ects are studied. Some new criteria on thepermanence, extinction and global attractivity...In this paper, the qualitative properties of general nonautonomous Lotka-Volterran-species competitive systems with impulsive e？ects are studied. Some new criteria on thepermanence, extinction and global attractivity of partial species are established by used themethods of inequalities estimate and Liapunov functions. As applications, nonautonomous twospecies Lotka-Volterra systems with impulses are discussed.展开更多
Salzburg is a beautiful city in Austria.It has old buildings,pretty streets and big mountains all around.The scenery is amazing!The famous movie The Sound of Music was filmed there.Many people visit Salzburg to see th...Salzburg is a beautiful city in Austria.It has old buildings,pretty streets and big mountains all around.The scenery is amazing!The famous movie The Sound of Music was filmed there.Many people visit Salzburg to see the locations from the movie.Some even do interviews there to ask people their feelings about the movie.One famous location from the movie is the Mirabell Gardens.The actors sang the song"Do-Re-Mi"there.The gardens have colorful flowers,statues and fountains.Salzburg is a fun and exciting place to visit and explore.展开更多
What is special about the sky bridge near Qingjing Farm?Qingjing Farm in Nantou is a popular place to visit.Every year,it has a Sheep Run Festival!Thousands of visitors go each year to cheer on their favorite sheep an...What is special about the sky bridge near Qingjing Farm?Qingjing Farm in Nantou is a popular place to visit.Every year,it has a Sheep Run Festival!Thousands of visitors go each year to cheer on their favorite sheep and take pictures as they run down the mountain roads.People can enjoy many performances,games and activities during the festival,too.展开更多
Fifty-five-year-old Shi Yizhong never imagined fireflies could become the foundation of a serious business.In 2022,Longshan Village in Huzhou’s Wuxing District collaborated with a young entrepreneurial team to create...Fifty-five-year-old Shi Yizhong never imagined fireflies could become the foundation of a serious business.In 2022,Longshan Village in Huzhou’s Wuxing District collaborated with a young entrepreneurial team to create a firefly campsite-a natural attraction where visitors can observe these glowing insects in a preserved habitat.The site quickly drew waves of tourists,who shared their experience online,recouping its initial investment in just two years.展开更多
基金Supported by the National Natural Science Foundation of China(61473340)Distinguished Professor Foundation of Qianjiang Scholar in Zhejiang Province(F703108L02)。
文摘We study the global dynamics of a rational diference equation with higher order,which includes many rational diference equations as its special cases.By some complicate computations and mathematical skills,we show that its unique nonnegative fixed point is globally attractive.As application,our results not only improve many known ones,but also solve several“Open Problems and Conjectures”given by Professors Ladas and Camouzis,et al.
文摘针对工业装配任务,尤其是不规则轴孔工件装配中,基于学习的前期样本质量低、训练过程不稳定等问题,提出一种融合引斥力模型(Attraction-Repulsion Model,ARM)引导机制和长短期记忆网络(Long Short Term Memory,LSTM)的柔性演员-评论家(Soft Actor-Critic,SAC)算法。首先,为解决训练初期探索效率低的问题,提出一种基于引斥力模型的策略引导机制,通过目标位置信息引导机械臂运动,加速收敛过程;其次,基于长短期记忆网络对算法的策略网络和价值网络进行改进,有效利用历史信息,增强策略学习能力,提高算法的收敛速度和稳定性。仿真结果表明,所提出的算法在行星减速器中心轴装配任务中取得显著的效果,装配成功率高达99.4%,与普通SAC算法相比,平均最大接触力和力矩分别降低了68.8%和79.2%。在物理环境中装配成功率达95%以上,最大接触力和力矩分别小于10 N和1.5 N·m,验证了算法的有效性。
基金Supported by the Science Foundation of Educational Committee of Hunan Province
文摘Consider the discrete Lasota Wazewska modelN n+1 -N n =-μN n +pe -rN n-k , n=0,1,2,...(*)where μ∈(0,1),r,p∈(0,∞) and k ∈N.A sufficient condition for all positive solutions of (*) to be attracted to its equilibrium N is obtained.It improves correspondent result obtained by Chen and Yu in 1999.
文摘The existence of positive solutions and the global attractivity of the difference equation Δy n=r ny nK-y n-l n K-cy n-l n are investigated. And some sufficient conditions are obtained,which greatly improve and extend the known results.
文摘Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.
文摘A population of interacting species is considered which is governed by a system of nonlinear difference equation.In the case of the interacting species with competition,a sufficient condition for global attractivity of an equilibrium state is derived.The result can be considered as a best discrete approximation of the continuous system.
基金Supported by The National Natural Science Foundation of P.R. China [60764003]The Scientific Research Programmes of Colleges in Xinjiang [XJEDU2007G01, XJEDU2006I05]+1 种基金The National Key Technologies R & D Program of China [2008BAI68B01]The Natural Science Foundation of Jiangxi Province [2008GZS0027]
文摘In this paper, the qualitative properties of general nonautonomous Lotka-Volterran-species competitive systems with impulsive e？ects are studied. Some new criteria on thepermanence, extinction and global attractivity of partial species are established by used themethods of inequalities estimate and Liapunov functions. As applications, nonautonomous twospecies Lotka-Volterra systems with impulses are discussed.
文摘Salzburg is a beautiful city in Austria.It has old buildings,pretty streets and big mountains all around.The scenery is amazing!The famous movie The Sound of Music was filmed there.Many people visit Salzburg to see the locations from the movie.Some even do interviews there to ask people their feelings about the movie.One famous location from the movie is the Mirabell Gardens.The actors sang the song"Do-Re-Mi"there.The gardens have colorful flowers,statues and fountains.Salzburg is a fun and exciting place to visit and explore.
文摘What is special about the sky bridge near Qingjing Farm?Qingjing Farm in Nantou is a popular place to visit.Every year,it has a Sheep Run Festival!Thousands of visitors go each year to cheer on their favorite sheep and take pictures as they run down the mountain roads.People can enjoy many performances,games and activities during the festival,too.
文摘Fifty-five-year-old Shi Yizhong never imagined fireflies could become the foundation of a serious business.In 2022,Longshan Village in Huzhou’s Wuxing District collaborated with a young entrepreneurial team to create a firefly campsite-a natural attraction where visitors can observe these glowing insects in a preserved habitat.The site quickly drew waves of tourists,who shared their experience online,recouping its initial investment in just two years.
