The paper generalizes the direct method of moving planes to the Logarithmic Laplacian system.Firstly,some key ingredients of the method are discussed,for example,Narrow region principle and Decay at infinity.Then,the ...The paper generalizes the direct method of moving planes to the Logarithmic Laplacian system.Firstly,some key ingredients of the method are discussed,for example,Narrow region principle and Decay at infinity.Then,the radial symmetry of the solution of the Logarithmic Laplacian system is obtained.展开更多
In this note,we prove a logarithmic Sobolev inequality which holds for compact submanifolds without a boundary in manifolds with asymptotically nonnegative sectional curvature.Like the Michale-Simon Sobolev inequality...In this note,we prove a logarithmic Sobolev inequality which holds for compact submanifolds without a boundary in manifolds with asymptotically nonnegative sectional curvature.Like the Michale-Simon Sobolev inequality,this inequality contains a term involving the mean curvature.展开更多
The potential for mitigating climate change is growing worldwide,with an increasing emphasis on reducing CO_(2)emissions and minimising the impact on the environment.African continent is faced with the unique challeng...The potential for mitigating climate change is growing worldwide,with an increasing emphasis on reducing CO_(2)emissions and minimising the impact on the environment.African continent is faced with the unique challenge of climate change whilst coping with extreme poverty,explosive population growth and economic difficulties.CO_(2)emission patterns in Africa are analysed in this study to understand primary CO_(2)sources and underlying driving forces further.Data are examined using gravity model,logarithmic mean divisia index and Tapio's decoupling indicator of CO_(2)emissions from economic development in 20 selected African countries during 1984-2014.Results reveal that CO_(2)emissions increased by 2.11%(453.73 million ton)over the research period.Gravity centre for African CO_(2)emissions had shifted towards the northeast direction.Population and economic growth were primary driving forces of CO_(2)emissions.Industrial structure and emission efficiency effects partially offset the growth of CO_(2)emissions.The economic growth effect was an offset factor in central African countries and Zimbabwe due to political instability and economic mismanagement.Industrial structure and emission efficiency were insufficient to decouple economic development from CO_(2)emissions and relieve the pressure of population explosion on CO_(2)emissions in Africa.Thus,future efforts in reducing CO_(2)emissions should focus on scaleup energy-efficient technologies,renewable energy update,emission pricing and long-term green development towards sustainable development goals by 2030.展开更多
Considering the variation of cohesion along the depth,the upper bound solution of active earth pressure for a rough inclined wall with sloped backfill is formulated based on a log-spiral failure mechanism.For a more a...Considering the variation of cohesion along the depth,the upper bound solution of active earth pressure for a rough inclined wall with sloped backfill is formulated based on a log-spiral failure mechanism.For a more accurate prediction,the influence of intermediate principal stress is taken into consideration using the unified strength theory.Converting the search for the active pressure to an optimization problem,the most critical failure surface can be located by a natural selection-based gravitational search algorithm(GSA).The proposed method is validated compared with existing methods for noncohesive and cohesive cases and proved to be more accordance with the limit equilibrium solution.The influences of the variation of soil cohesion and intermediate principal stress on active earth pressure coefficient are then fully studied.It can be concluded that both the variations of soil cohesion and intermediate principal stress have a significant influence on the active earth pressure coefficient.展开更多
Kernel adaptive filters(KAFs)have sparked substantial attraction for online non-linear learning applications.It is noted that the effectiveness of KAFs is highly reliant on a rational learning criterion.Concerning thi...Kernel adaptive filters(KAFs)have sparked substantial attraction for online non-linear learning applications.It is noted that the effectiveness of KAFs is highly reliant on a rational learning criterion.Concerning this,the logarithmic hyperbolic cosine(lncosh)criterion with better robustness and convergence has drawn attention in recent studies.However,existing lncosh loss-based KAFs use the stochastic gradient descent(SGD)for optimization,which lack a trade-off between the convergence speed and accuracy.But recursion-based KAFs can provide more effective filtering performance.Therefore,a Nyström method-based robust sparse kernel recursive least lncosh loss algorithm is derived in this article.Experiments via measures and synthetic data against the non-Gaussian noise confirm the superiority with regard to the robustness,accuracy performance,and computational cost.展开更多
In this paper,we study a porous thermoelastic problem with microtemperatures assuming parabolic higher order in time derivatives for the thermal variables.The model is derived and written as a coupled linear system.Th...In this paper,we study a porous thermoelastic problem with microtemperatures assuming parabolic higher order in time derivatives for the thermal variables.The model is derived and written as a coupled linear system.Then,a uniqueness result is proved by using the logarithmic convexity method in the case that we do not assume that the mechanical energy is positive definite.Finally,the existence of the solution is obtained by introducing an energy function and applying the theory of linear semigroups.展开更多
We consider the logarithmic elliptic equation with singular nonlinearity {Δu+ulogu^(2)+λ/u^(γ)=0,in Ω,u>0,in Ω,u=0,on δΩ,where Ω⊂R^(N)(N≥3)is a bounded domain with a smooth boundary,0<γ<1 andλis a ...We consider the logarithmic elliptic equation with singular nonlinearity {Δu+ulogu^(2)+λ/u^(γ)=0,in Ω,u>0,in Ω,u=0,on δΩ,where Ω⊂R^(N)(N≥3)is a bounded domain with a smooth boundary,0<γ<1 andλis a positive constant.By using a variational method and the critical point theory for a nonsmooth functional,we obtain the existence of two positive solutions.This result generalizes and improves upon recent results in the literature.展开更多
The vibration attenuation and damping characteristics of carbon fiber reinforced composite laminates with different thicknesses were investigated by hammering experiments under free boundary constraints in different d...The vibration attenuation and damping characteristics of carbon fiber reinforced composite laminates with different thicknesses were investigated by hammering experiments under free boundary constraints in different directions.The dynamic signal testing and analysis system is applied to collect and analyze the vibration signals of the composite specimens,and combine the self-spectrum analysis and logarithmic decay method to identify the fundamental frequencies of different specimens and calculate the damping ratios of different directions of the specimens.The results showed that the overall stiffness of the specimen increased with the increase of the specimen thickness,and when the thickness of the sample increases from 24mm to 32mm,the fundamental frequency increases by 35.1%,the vibration showed the same vibration attenuation and energy dissipation characteristics in the 0°and 90°directions of the specimen,compared with the specimen in the 45°direction,which was less likely to be excited and had poorer vibration attenuation ability,while the upper and lower surfaces of the same specimen showed slightly different attenuation characteristics to the vibration,the maximum difference of damping capacity between top and bottom surfaces of CFRP plates is about 70%.展开更多
t The logarithmic quadratic proximal(LQP)regularization is a popular and powerful proximal regularization technique for solving monotone variational inequalities with nonnegative constraints.In this paper,we propose ...t The logarithmic quadratic proximal(LQP)regularization is a popular and powerful proximal regularization technique for solving monotone variational inequalities with nonnegative constraints.In this paper,we propose an implementable two-step method for solving structured variational inequality problems by combining LQP regularization and projection method.The proposed algorithm consists of two parts.The first step generates a pair of predictors via inexactly solving a system of nonlinear equations.Then,the second step updates the iterate via a simple correction step.We establish the global convergence of the new method under mild assumptions.To improve the numerical performance of our new method,we further present a self-adaptive version and implement it to solve a traffic equilibrium problem.The numerical results further demonstrate the efficiency of the proposed method.展开更多
In the paper,we try to study the mechanism of the existence of Gaussian waves in high degree logarithmic nonlinear wave motions.We first construct two model equations which include the high order dispersion and a seco...In the paper,we try to study the mechanism of the existence of Gaussian waves in high degree logarithmic nonlinear wave motions.We first construct two model equations which include the high order dispersion and a second degree logarithmic nonlinearity.And then we prove that the Gaussian waves can exist for high degree logarithmic nonlinear wave equations if the balance between the dispersion and logarithmic nonlinearity is kept.Our mathematical tool is the logarithmic trial equation method.展开更多
基金Supported by the National Natural Science Foundation of China(11501342,12001344)。
文摘The paper generalizes the direct method of moving planes to the Logarithmic Laplacian system.Firstly,some key ingredients of the method are discussed,for example,Narrow region principle and Decay at infinity.Then,the radial symmetry of the solution of the Logarithmic Laplacian system is obtained.
基金Supported by the NSFC(11771087,12171091 and 11831005)。
文摘In this note,we prove a logarithmic Sobolev inequality which holds for compact submanifolds without a boundary in manifolds with asymptotically nonnegative sectional curvature.Like the Michale-Simon Sobolev inequality,this inequality contains a term involving the mean curvature.
基金supported by the National Water Pollution Control and Treatment Science and Technology Major Project(No.2017ZX07101001)the National Natural Science Foundation of China(Nos.41690142 and 41371535)the Fundamental Research Funds for the Central Universities(No.SWU019047)。
文摘The potential for mitigating climate change is growing worldwide,with an increasing emphasis on reducing CO_(2)emissions and minimising the impact on the environment.African continent is faced with the unique challenge of climate change whilst coping with extreme poverty,explosive population growth and economic difficulties.CO_(2)emission patterns in Africa are analysed in this study to understand primary CO_(2)sources and underlying driving forces further.Data are examined using gravity model,logarithmic mean divisia index and Tapio's decoupling indicator of CO_(2)emissions from economic development in 20 selected African countries during 1984-2014.Results reveal that CO_(2)emissions increased by 2.11%(453.73 million ton)over the research period.Gravity centre for African CO_(2)emissions had shifted towards the northeast direction.Population and economic growth were primary driving forces of CO_(2)emissions.Industrial structure and emission efficiency effects partially offset the growth of CO_(2)emissions.The economic growth effect was an offset factor in central African countries and Zimbabwe due to political instability and economic mismanagement.Industrial structure and emission efficiency were insufficient to decouple economic development from CO_(2)emissions and relieve the pressure of population explosion on CO_(2)emissions in Africa.Thus,future efforts in reducing CO_(2)emissions should focus on scaleup energy-efficient technologies,renewable energy update,emission pricing and long-term green development towards sustainable development goals by 2030.
基金Project(2016YFC0800200)supported by the National Key Research Plan of China。
文摘Considering the variation of cohesion along the depth,the upper bound solution of active earth pressure for a rough inclined wall with sloped backfill is formulated based on a log-spiral failure mechanism.For a more accurate prediction,the influence of intermediate principal stress is taken into consideration using the unified strength theory.Converting the search for the active pressure to an optimization problem,the most critical failure surface can be located by a natural selection-based gravitational search algorithm(GSA).The proposed method is validated compared with existing methods for noncohesive and cohesive cases and proved to be more accordance with the limit equilibrium solution.The influences of the variation of soil cohesion and intermediate principal stress on active earth pressure coefficient are then fully studied.It can be concluded that both the variations of soil cohesion and intermediate principal stress have a significant influence on the active earth pressure coefficient.
基金supported in part by the National Natural Science Foundation of China under Grants No.62027803,No.61601096,No.61971111,and No.61801089in part by the Science and Technology Program under Grants No.8091C24,No.2021JCJQJJ0949,and No.2022JCJQJJ0784in part by the Industrial Technology Development Program under Grant No.2020110C041.
文摘Kernel adaptive filters(KAFs)have sparked substantial attraction for online non-linear learning applications.It is noted that the effectiveness of KAFs is highly reliant on a rational learning criterion.Concerning this,the logarithmic hyperbolic cosine(lncosh)criterion with better robustness and convergence has drawn attention in recent studies.However,existing lncosh loss-based KAFs use the stochastic gradient descent(SGD)for optimization,which lack a trade-off between the convergence speed and accuracy.But recursion-based KAFs can provide more effective filtering performance.Therefore,a Nyström method-based robust sparse kernel recursive least lncosh loss algorithm is derived in this article.Experiments via measures and synthetic data against the non-Gaussian noise confirm the superiority with regard to the robustness,accuracy performance,and computational cost.
基金part of the project(No.PID2019-105118GB-I00),funded by the Spanish Ministry of Science,Innovation and Universities and FEDER“A way to make Europe”。
文摘In this paper,we study a porous thermoelastic problem with microtemperatures assuming parabolic higher order in time derivatives for the thermal variables.The model is derived and written as a coupled linear system.Then,a uniqueness result is proved by using the logarithmic convexity method in the case that we do not assume that the mechanical energy is positive definite.Finally,the existence of the solution is obtained by introducing an energy function and applying the theory of linear semigroups.
基金supported by Natural Science Foundation of Guizhou Minzu University(20185773-YB03)supported by Fundamental Research Funds of China West Normal University(18B015)+2 种基金Innovative Research Team of China West Normal University(CXTD2018-8)supported by National Natural Science Foundation of China(11861021)supported by National Natural Science Foundation of China(11661021)。
文摘We consider the logarithmic elliptic equation with singular nonlinearity {Δu+ulogu^(2)+λ/u^(γ)=0,in Ω,u>0,in Ω,u=0,on δΩ,where Ω⊂R^(N)(N≥3)is a bounded domain with a smooth boundary,0<γ<1 andλis a positive constant.By using a variational method and the critical point theory for a nonsmooth functional,we obtain the existence of two positive solutions.This result generalizes and improves upon recent results in the literature.
基金supported by the Fundamental Research Funds for the Central Universities [grant nos.DUT21LAB108,DUT22LAB401].
文摘The vibration attenuation and damping characteristics of carbon fiber reinforced composite laminates with different thicknesses were investigated by hammering experiments under free boundary constraints in different directions.The dynamic signal testing and analysis system is applied to collect and analyze the vibration signals of the composite specimens,and combine the self-spectrum analysis and logarithmic decay method to identify the fundamental frequencies of different specimens and calculate the damping ratios of different directions of the specimens.The results showed that the overall stiffness of the specimen increased with the increase of the specimen thickness,and when the thickness of the sample increases from 24mm to 32mm,the fundamental frequency increases by 35.1%,the vibration showed the same vibration attenuation and energy dissipation characteristics in the 0°and 90°directions of the specimen,compared with the specimen in the 45°direction,which was less likely to be excited and had poorer vibration attenuation ability,while the upper and lower surfaces of the same specimen showed slightly different attenuation characteristics to the vibration,the maximum difference of damping capacity between top and bottom surfaces of CFRP plates is about 70%.
基金the National Natural Science Foundation of China(Nos.11571087 and 71471051)the National Natural Science Foundation of Zhejiang Province(No.LY17A010028)+1 种基金The third author is supported by the National Natural Science Foundation of China(Nos.11431002 and 11401315)Jiangsu Provincial National Natural Science Foundation of China(No.BK20140914).
文摘t The logarithmic quadratic proximal(LQP)regularization is a popular and powerful proximal regularization technique for solving monotone variational inequalities with nonnegative constraints.In this paper,we propose an implementable two-step method for solving structured variational inequality problems by combining LQP regularization and projection method.The proposed algorithm consists of two parts.The first step generates a pair of predictors via inexactly solving a system of nonlinear equations.Then,the second step updates the iterate via a simple correction step.We establish the global convergence of the new method under mild assumptions.To improve the numerical performance of our new method,we further present a self-adaptive version and implement it to solve a traffic equilibrium problem.The numerical results further demonstrate the efficiency of the proposed method.
文摘In the paper,we try to study the mechanism of the existence of Gaussian waves in high degree logarithmic nonlinear wave motions.We first construct two model equations which include the high order dispersion and a second degree logarithmic nonlinearity.And then we prove that the Gaussian waves can exist for high degree logarithmic nonlinear wave equations if the balance between the dispersion and logarithmic nonlinearity is kept.Our mathematical tool is the logarithmic trial equation method.
