This paper is concerned with the following attraction-repulsion chemotaxis system with p-Laplacian diffusion and logistic source:■The system here is under a homogenous Neumann boundary condition in a bounded domainΩ...This paper is concerned with the following attraction-repulsion chemotaxis system with p-Laplacian diffusion and logistic source:■The system here is under a homogenous Neumann boundary condition in a bounded domainΩ ■ R^(n)(n≥2),with χ,ξ,α,β,γ,δ,k_(1),k_(2)> 0,p> 2.In addition,the function f is smooth and satisfies that f(s)≤κ-μs~l for all s≥0,with κ ∈ R,μ> 0,l> 1.It is shown that(ⅰ)if l> max{2k_(1),(2k_(1)n)/(2+n)+1/(p-1)},then system possesses a global bounded weak solution and(ⅱ)if k_(2)> max{2k_(1)-1,(2k_(1)n)/(2+n)+(2-p)/(p-1)} with l> 2,then system possesses a global bounded weak solution.展开更多
The logistics system is a complex ecosystem. Ecological logistics （EL） is development trend of modern logistics, and of important practical significance. Effective use of resources and environmental protection shoul...The logistics system is a complex ecosystem. Ecological logistics （EL） is development trend of modern logistics, and of important practical significance. Effective use of resources and environmental protection should be put in the top position of logistics development. To strengthen research on logistics ecologization and realize ecological and analyzes their relationship.展开更多
Under the analysis framework of output distance function,this paper makes overall measurement of rural Agriculture Logistics Efficiency( ALE) by constructing non-parametric production frontier function model using rel...Under the analysis framework of output distance function,this paper makes overall measurement of rural Agriculture Logistics Efficiency( ALE) by constructing non-parametric production frontier function model using related panel date of 28 provinces over the period1994-2014 in China. The accession to the WTO is the most important milestone in the process of China's globalization. It employs the bi-directional fixed effects model and the difference in differences( DID) method to study the impacts of globalization( joining WTO) on ALE and its mechanism of action in the context of China. The results show that the WTO makes ALE of China generally increased by about 34. 2%,promoting ALE with a long-term dynamic gradual process; long-term impact of globalization on ALE is about 83. 3%,which is higher than shortterm effect; the promotion of ALE is obtained mainly by the improvement of rural logistics infrastructure,rural informatization level,regional division of agriculture and the quality of rural labor force brought by globalization; agriculture logistics professional level has not yet acquired obvious enhancement during the process of globalization in China so far.展开更多
In this paper, sufficient conditions are obtained for the tive steady state of the delay-logistic equation to be a global attractor.An application of the results also solves aa conjecture of Gopalsamy.
This paper studies the global attractivity of the positive equilibrium 1 of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n=0,1,2,...,(*)where {p n} is a sequence of positive real n...This paper studies the global attractivity of the positive equilibrium 1 of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n=0,1,2,...,(*)where {p n} is a sequence of positive real numbers, {τ(n)} is a nondecreasing sequence of integers, τ(n)<n and lim n→∞τ(n)=∞ .It is proved that ifnj=τ(n)p j≤54 for sufficiently large n and ∞j=0p j=∞,then all positive solutions of Eq.(*) tend to 1 as n→∞ .The results improve the existing results in literature.展开更多
In this paper,we consider a quasilinear parabolic-parabolic chemotaxis model with nonlinear diffusivity,aggregation and logistic damping source:■where k1 epu≤D（u） or k1 up≤D（u）;k2 equ≤S（u）≤k3 equ;g（u）≤a-...In this paper,we consider a quasilinear parabolic-parabolic chemotaxis model with nonlinear diffusivity,aggregation and logistic damping source:■where k1 epu≤D（u） or k1 up≤D（u）;k2 equ≤S（u）≤k3 equ;g（u）≤a-beku.It is proved that,if q <k-1 or q=k-1 and b> b0 for some constant b0> 0,then there exists a unique classical solution which is globally bounded.The results show the effect of the aggregation and the logistic damping source on the existence of globally bounded solutions.展开更多
Sufficient conditions are presented for the asymptotic behavior of all positive solutions of the multiplicative delay Logistic equation about the positive equilibrium K. The case when r(t) =r and gj(t) = t - Tj or gj(...Sufficient conditions are presented for the asymptotic behavior of all positive solutions of the multiplicative delay Logistic equation about the positive equilibrium K. The case when r(t) =r and gj(t) = t - Tj or gj(t) = [t - kj], [.] denoting the greatest integer function,where r, Tj and kj are positive constants, j = 1, 2,... m, ale also included.展开更多
Simulated annealing(SA) algorithm is a heuristic algorithm,proposed one approximation algorithm of solving optimization combinatorial problems inspired by objects in the annealing process of heating crunch. The algori...Simulated annealing(SA) algorithm is a heuristic algorithm,proposed one approximation algorithm of solving optimization combinatorial problems inspired by objects in the annealing process of heating crunch. The algorithm is superior to the traditional greedy algorithm,which avoids falling into local optimum and reaches global optimum. There are often some problems to find the shortest path,etc in the logistics and distribution network, and we need optimization for logistics and distribution path in order to achieve the shortest,best,most economical,and so on. The paper uses an example of SA algorithm validation to verify it,and the method is proved to be feasible.展开更多
Climate change is widely recognized as the major environmental problem facing the globe today. One of the most urgent environmental problems facing shipping industry is the reduction of GHG （greenhouse gas） emission...Climate change is widely recognized as the major environmental problem facing the globe today. One of the most urgent environmental problems facing shipping industry is the reduction of GHG （greenhouse gas） emissions from its operations. Given the growing concern of the international community on ＂the deep reduction of global GHG emissions＂, it cannot be expected that the non-regulation of maritime GHG emissions can further continue. This paper investigates the main challenges and threats of the development of two MBMs （market-based measures） for the reduction of GHG emissions from international shipping, i.e., the ＂global levy scheme on maritime GHG emissions＂ and the ＂maritime emission trading scheme＂. A SWOT （strengths weaknesses opportunities threat） analysis is used, in this survey, to evaluate the environmental effectiveness as well as the easiness of implementation of the two policy options. Moreover, we make apparent their strengths and weaknesses concerning abatement of maritime GHG emissions. Given the fact that the discussion regarding the implementation of some MBMs with maritime GHG-emission reduction potential is still carried out with the exception of EEDI （energy efficiency design index） and SEEMP （ship energy efficiency management plan）, this paper＇s results present special significance, as they could be further analyzed and taken into account during the adoption of any future MBM for the reduction of maritime GHG emissions.展开更多
Over the last decade, the private equity （PE） industry, primarily venture capital and leveraged buyout investments, has matured massively. Consequently, public interest towards that particular asset class has increa...Over the last decade, the private equity （PE） industry, primarily venture capital and leveraged buyout investments, has matured massively. Consequently, public interest towards that particular asset class has increased rapidly. This study seeks to empirically assess the determinants of private equity funds＇ （PEFs） performance around the world. The study comprises a panel data of 103 publicly traded PEFs globally for the period of 2007-2013. Generalized least squares （GLS） technique is employed to regress the explanatory variables. The objective is accentuated on the major contributing factors that make a PEF successful. The analysis, in this paper, examines the effect of fund size, investment size, geographical focus, and industrial specialization on return. The empirical results provide evidence that： （1） Fund size and industrial specialization were observed to have an insignificant influence on the funds＇ returns in our panels; （2） Investment size is positively related to fund performance, indicating that larger deal sizes exhibited superior performance level; and （3） Geographical focus exhibited a negative association with fund performance, leading to the conclusion that limited geographical deployment of funds or absence of market diversification resulted in a fall in funds＇ returns. Consequently, to proxy for return of funds, stock prices of listed PEFs under LPEQ listings were employed.展开更多
Urban road pricing schemes are becoming increasingly popular among researchers and politicians as they promise a handle on increasing inner city traffic and economy as well as sustainable improvements for cities facin...Urban road pricing schemes are becoming increasingly popular among researchers and politicians as they promise a handle on increasing inner city traffic and economy as well as sustainable improvements for cities facing huge congestion and pollution problems. As in the cases of London and Stockholm, many European cities are going to implement such toll systems, especially as also the European Commission is voting for such pricing schemes in the recent white book on transportation and traffic, This research therefore provides a description of different urban road pricing schemes, their cost implications for city （last mile） transport as well as the decision and management options derived from these schemes for logistics companies. These options are furthermore checked regarding their advantages and disadvantages under the described toll schemes.展开更多
国内物流产业将进行新一轮物流产业升级,而升级的发展路径以及发展战略选择尚未见学者研究,借鉴全球价值链(global logistics value chain,GVC和全球物流价值链(global logistics value chain,GLVC理论,在GVC的基础上,提出了GLVC的定义...国内物流产业将进行新一轮物流产业升级,而升级的发展路径以及发展战略选择尚未见学者研究,借鉴全球价值链(global logistics value chain,GVC和全球物流价值链(global logistics value chain,GLVC理论,在GVC的基础上,提出了GLVC的定义,阐述了产业升级的内涵;从内外角度提出了我国物流产业升级的内部动力和外部动力的构成,并进行了基于GVC和GLVC的物流产业升级动力分析;给出了物流产业升级范围扩展模式和升级深度发展模式,并给出了两种物流产业升级模式;提出了我国物流产业升级战略选择的四点思路。展开更多
基金supported by the National Natural Science Foundation of China(12301251,12271232)the Natural Science Foundation of Shandong Province,China(ZR2021QA038)the Scientific Research Foundation of Linyi University,China(LYDX2020BS014)。
文摘This paper is concerned with the following attraction-repulsion chemotaxis system with p-Laplacian diffusion and logistic source:■The system here is under a homogenous Neumann boundary condition in a bounded domainΩ ■ R^(n)(n≥2),with χ,ξ,α,β,γ,δ,k_(1),k_(2)> 0,p> 2.In addition,the function f is smooth and satisfies that f(s)≤κ-μs~l for all s≥0,with κ ∈ R,μ> 0,l> 1.It is shown that(ⅰ)if l> max{2k_(1),(2k_(1)n)/(2+n)+1/(p-1)},then system possesses a global bounded weak solution and(ⅱ)if k_(2)> max{2k_(1)-1,(2k_(1)n)/(2+n)+(2-p)/(p-1)} with l> 2,then system possesses a global bounded weak solution.
基金the Foundation for the Soft Science of Jiangsu Province (Grant No. BR2007506)
文摘The logistics system is a complex ecosystem. Ecological logistics （EL） is development trend of modern logistics, and of important practical significance. Effective use of resources and environmental protection should be put in the top position of logistics development. To strengthen research on logistics ecologization and realize ecological and analyzes their relationship.
基金the Social Science Foundation of Hunan Province in China(2014JD29)the National Social Science Foundation of China(12BJY123)the National Social Science Foundation of China(15AJL006)
文摘Under the analysis framework of output distance function,this paper makes overall measurement of rural Agriculture Logistics Efficiency( ALE) by constructing non-parametric production frontier function model using related panel date of 28 provinces over the period1994-2014 in China. The accession to the WTO is the most important milestone in the process of China's globalization. It employs the bi-directional fixed effects model and the difference in differences( DID) method to study the impacts of globalization( joining WTO) on ALE and its mechanism of action in the context of China. The results show that the WTO makes ALE of China generally increased by about 34. 2%,promoting ALE with a long-term dynamic gradual process; long-term impact of globalization on ALE is about 83. 3%,which is higher than shortterm effect; the promotion of ALE is obtained mainly by the improvement of rural logistics infrastructure,rural informatization level,regional division of agriculture and the quality of rural labor force brought by globalization; agriculture logistics professional level has not yet acquired obvious enhancement during the process of globalization in China so far.
文摘In this paper, sufficient conditions are obtained for the tive steady state of the delay-logistic equation to be a global attractor.An application of the results also solves aa conjecture of Gopalsamy.
文摘This paper studies the global attractivity of the positive equilibrium 1 of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n=0,1,2,...,(*)where {p n} is a sequence of positive real numbers, {τ(n)} is a nondecreasing sequence of integers, τ(n)<n and lim n→∞τ(n)=∞ .It is proved that ifnj=τ(n)p j≤54 for sufficiently large n and ∞j=0p j=∞,then all positive solutions of Eq.(*) tend to 1 as n→∞ .The results improve the existing results in literature.
基金supported by Shandong Provincial Natural Science Foundation,China(ZR2017LA003)
文摘In this paper,we consider a quasilinear parabolic-parabolic chemotaxis model with nonlinear diffusivity,aggregation and logistic damping source:■where k1 epu≤D（u） or k1 up≤D（u）;k2 equ≤S（u）≤k3 equ;g（u）≤a-beku.It is proved that,if q <k-1 or q=k-1 and b> b0 for some constant b0> 0,then there exists a unique classical solution which is globally bounded.The results show the effect of the aggregation and the logistic damping source on the existence of globally bounded solutions.
文摘Sufficient conditions are presented for the asymptotic behavior of all positive solutions of the multiplicative delay Logistic equation about the positive equilibrium K. The case when r(t) =r and gj(t) = t - Tj or gj(t) = [t - kj], [.] denoting the greatest integer function,where r, Tj and kj are positive constants, j = 1, 2,... m, ale also included.
基金National Natural Science Foundation of China(No.50574037)Henan Soft Science Research Project(No.102400410033No.102400410032)
文摘Simulated annealing(SA) algorithm is a heuristic algorithm,proposed one approximation algorithm of solving optimization combinatorial problems inspired by objects in the annealing process of heating crunch. The algorithm is superior to the traditional greedy algorithm,which avoids falling into local optimum and reaches global optimum. There are often some problems to find the shortest path,etc in the logistics and distribution network, and we need optimization for logistics and distribution path in order to achieve the shortest,best,most economical,and so on. The paper uses an example of SA algorithm validation to verify it,and the method is proved to be feasible.
文摘Climate change is widely recognized as the major environmental problem facing the globe today. One of the most urgent environmental problems facing shipping industry is the reduction of GHG （greenhouse gas） emissions from its operations. Given the growing concern of the international community on ＂the deep reduction of global GHG emissions＂, it cannot be expected that the non-regulation of maritime GHG emissions can further continue. This paper investigates the main challenges and threats of the development of two MBMs （market-based measures） for the reduction of GHG emissions from international shipping, i.e., the ＂global levy scheme on maritime GHG emissions＂ and the ＂maritime emission trading scheme＂. A SWOT （strengths weaknesses opportunities threat） analysis is used, in this survey, to evaluate the environmental effectiveness as well as the easiness of implementation of the two policy options. Moreover, we make apparent their strengths and weaknesses concerning abatement of maritime GHG emissions. Given the fact that the discussion regarding the implementation of some MBMs with maritime GHG-emission reduction potential is still carried out with the exception of EEDI （energy efficiency design index） and SEEMP （ship energy efficiency management plan）, this paper＇s results present special significance, as they could be further analyzed and taken into account during the adoption of any future MBM for the reduction of maritime GHG emissions.
文摘Over the last decade, the private equity （PE） industry, primarily venture capital and leveraged buyout investments, has matured massively. Consequently, public interest towards that particular asset class has increased rapidly. This study seeks to empirically assess the determinants of private equity funds＇ （PEFs） performance around the world. The study comprises a panel data of 103 publicly traded PEFs globally for the period of 2007-2013. Generalized least squares （GLS） technique is employed to regress the explanatory variables. The objective is accentuated on the major contributing factors that make a PEF successful. The analysis, in this paper, examines the effect of fund size, investment size, geographical focus, and industrial specialization on return. The empirical results provide evidence that： （1） Fund size and industrial specialization were observed to have an insignificant influence on the funds＇ returns in our panels; （2） Investment size is positively related to fund performance, indicating that larger deal sizes exhibited superior performance level; and （3） Geographical focus exhibited a negative association with fund performance, leading to the conclusion that limited geographical deployment of funds or absence of market diversification resulted in a fall in funds＇ returns. Consequently, to proxy for return of funds, stock prices of listed PEFs under LPEQ listings were employed.
文摘Urban road pricing schemes are becoming increasingly popular among researchers and politicians as they promise a handle on increasing inner city traffic and economy as well as sustainable improvements for cities facing huge congestion and pollution problems. As in the cases of London and Stockholm, many European cities are going to implement such toll systems, especially as also the European Commission is voting for such pricing schemes in the recent white book on transportation and traffic, This research therefore provides a description of different urban road pricing schemes, their cost implications for city （last mile） transport as well as the decision and management options derived from these schemes for logistics companies. These options are furthermore checked regarding their advantages and disadvantages under the described toll schemes.
文摘国内物流产业将进行新一轮物流产业升级,而升级的发展路径以及发展战略选择尚未见学者研究,借鉴全球价值链(global logistics value chain,GVC和全球物流价值链(global logistics value chain,GLVC理论,在GVC的基础上,提出了GLVC的定义,阐述了产业升级的内涵;从内外角度提出了我国物流产业升级的内部动力和外部动力的构成,并进行了基于GVC和GLVC的物流产业升级动力分析;给出了物流产业升级范围扩展模式和升级深度发展模式,并给出了两种物流产业升级模式;提出了我国物流产业升级战略选择的四点思路。
