A stochastic local limited one-dimensional rice-pile model is numerically investigated. The distributions for avalanche sizes have a clear power-law behavior and it displays a simple finite size scaling. We obtain the...A stochastic local limited one-dimensional rice-pile model is numerically investigated. The distributions for avalanche sizes have a clear power-law behavior and it displays a simple finite size scaling. We obtain the avalanche exponents Ts= 1.54±0.10,βs = 2.17±0.10 and TT = 1.80±0.10, βT =1.46 ± 0.10. This self-organized critical model belongs to the same universality class with the Oslo rice-pile model studied by K. Christensen et al. [Phys. Rev. Lett. 77 （1996） 107], a rice-pile model studied by L.A.N. Amaral et al. [Phys. Rev. E 54 （1996） 4512], and a simple deterministic self-organized critical model studied by M.S. Vieira [Phys. Rev. E 61 （2000） 6056].展开更多
In this paper we, firstly, classify the complex networks in which the nodes are of the lifetime distribution. Secondly, in order to study complex networks in terms of queuing system and homogeneous Markov chain, we es...In this paper we, firstly, classify the complex networks in which the nodes are of the lifetime distribution. Secondly, in order to study complex networks in terms of queuing system and homogeneous Markov chain, we establish the relation between the complex networks and queuing system, providing a new way of studying complex networks. Thirdly, we prove that there exist stationary degree distributions of M-G-P network, and obtain the analytic expression of the distribution by means of Markov chain theory. We also obtain the average path length and clustering coefficient of the network. The results show that M-G-P network is not only scale-free but also of a small-world feature in proper conditions.展开更多
The distribution of market shares within an industry is a relevant performance measure for managers and policy makers, for it allow to determine whether a given industry is competitive or not. Usually, the perfect com...The distribution of market shares within an industry is a relevant performance measure for managers and policy makers, for it allow to determine whether a given industry is competitive or not. Usually, the perfect competition model is the reference to judge the efficiency of markets. However, there is enough empirical evidence that shows that one of the most evident features of global firms is that both their size and market are Zipf-distributed. In this paper, we show that the distribution of market shares in the world cola-drink market is skewed, but it does not follow Zipf＇s law, thus it is inadequate to generalize it to any kind of market.展开更多
＂BIM （building information modeling）＂ and ＂sustainability＂ are two frequently used words in construction and academia today. BIM is a design-oriented tool, which generates a virtual three-dimensional model of a ...＂BIM （building information modeling）＂ and ＂sustainability＂ are two frequently used words in construction and academia today. BIM is a design-oriented tool, which generates a virtual three-dimensional model of a project. Sustainability refers to prudent use of earth＇s natural resources, and construction sustainability is the application of this principle to building activities. Societies in general and the construction industry in particular--one of the largest in terms of natural resources consumed and waste produced--place high hopes on BIM and the principles of sustainability to reduce consumption and waste and to increase industry productivity. BIM＇s capabilities and limitations, currently more focused on model creation and energy simulations, are not well understood as they relate to construction sustainability and its goals. No method yet exists to evaluate BIM＇s contribution comprehensively to construction sustainability goals. This study presents a construction sustainability goals contribution matrix for BIM. The matrix indicates that this contribution may be more limited than it is commonly thought.展开更多
基金supported by the Science Foundation of Henan University of Science and Technology under Grant Nos.05-032 and 2006QN033
文摘A stochastic local limited one-dimensional rice-pile model is numerically investigated. The distributions for avalanche sizes have a clear power-law behavior and it displays a simple finite size scaling. We obtain the avalanche exponents Ts= 1.54±0.10,βs = 2.17±0.10 and TT = 1.80±0.10, βT =1.46 ± 0.10. This self-organized critical model belongs to the same universality class with the Oslo rice-pile model studied by K. Christensen et al. [Phys. Rev. Lett. 77 （1996） 107], a rice-pile model studied by L.A.N. Amaral et al. [Phys. Rev. E 54 （1996） 4512], and a simple deterministic self-organized critical model studied by M.S. Vieira [Phys. Rev. E 61 （2000） 6056].
基金Project supported by the Shanghai Leading Academic Discipline Project, China （Grant No T0502） and by the Shanghai Municipal Education Commission Natural Science Foundation, China （Grant No 05EZ35）.
文摘In this paper we, firstly, classify the complex networks in which the nodes are of the lifetime distribution. Secondly, in order to study complex networks in terms of queuing system and homogeneous Markov chain, we establish the relation between the complex networks and queuing system, providing a new way of studying complex networks. Thirdly, we prove that there exist stationary degree distributions of M-G-P network, and obtain the analytic expression of the distribution by means of Markov chain theory. We also obtain the average path length and clustering coefficient of the network. The results show that M-G-P network is not only scale-free but also of a small-world feature in proper conditions.
文摘The distribution of market shares within an industry is a relevant performance measure for managers and policy makers, for it allow to determine whether a given industry is competitive or not. Usually, the perfect competition model is the reference to judge the efficiency of markets. However, there is enough empirical evidence that shows that one of the most evident features of global firms is that both their size and market are Zipf-distributed. In this paper, we show that the distribution of market shares in the world cola-drink market is skewed, but it does not follow Zipf＇s law, thus it is inadequate to generalize it to any kind of market.
文摘＂BIM （building information modeling）＂ and ＂sustainability＂ are two frequently used words in construction and academia today. BIM is a design-oriented tool, which generates a virtual three-dimensional model of a project. Sustainability refers to prudent use of earth＇s natural resources, and construction sustainability is the application of this principle to building activities. Societies in general and the construction industry in particular--one of the largest in terms of natural resources consumed and waste produced--place high hopes on BIM and the principles of sustainability to reduce consumption and waste and to increase industry productivity. BIM＇s capabilities and limitations, currently more focused on model creation and energy simulations, are not well understood as they relate to construction sustainability and its goals. No method yet exists to evaluate BIM＇s contribution comprehensively to construction sustainability goals. This study presents a construction sustainability goals contribution matrix for BIM. The matrix indicates that this contribution may be more limited than it is commonly thought.
