Using the case study methodology, firm＇s competition behavior in strategic network and strategic ecosystems are analyzed. With the ecology view, there is consistency between strategic network and strategic ecosystem....Using the case study methodology, firm＇s competition behavior in strategic network and strategic ecosystems are analyzed. With the ecology view, there is consistency between strategic network and strategic ecosystem. Enterprise should pursue for suitable ecological niche to hold a strategic competitive power.展开更多
In this paper, based on a class of multi-group epidemic models of SEIR type with bilinear incidences, we introduce a vaccination compartment, leading to multi-group SVEIR model. We establish that the global dynamics a...In this paper, based on a class of multi-group epidemic models of SEIR type with bilinear incidences, we introduce a vaccination compartment, leading to multi-group SVEIR model. We establish that the global dynamics are completely determined by the basic reproduction number R0V which is defined by the spectral radius of the next generation matrix. Our proofs of global stability of the equilibria utilize a graph-theoretical approach to the method of Lyapunov functionals. Mathematical results suggest that vaccination is helpful for disease control by decreasing the basic reproduction number. However, there is a necessary condition for successful elimination of disease. If the time for the vaccines to obtain immunity or the possibility for them to be infected before acquiring immunity is neglected in each group, this condition will be satisfied and the disease can always be eradicated by suitable vaccination strategies. This may lead to over evaluation for the effect of vaccination.展开更多
This paper tells us a complex story on the historic evolution of preventive conser vation of architectural heritage in Italy.Firstly,it introduces Cesare Brandi's Theory of Resto ration,pointing out the peculiar s...This paper tells us a complex story on the historic evolution of preventive conser vation of architectural heritage in Italy.Firstly,it introduces Cesare Brandi's Theory of Resto ration,pointing out the peculiar sense of the word Restoration in Brandi's system other than the common sense in the international discourse,the limits of Brandi's theory to architectural conservation and his prophecy on preventive restoration.Then it talks about the differentframework and practices of preventive conservation in the field of built heritage compared to the museum sector,the milestone of Giovanni Urbani's pilot project on programmed conser.vation and the leading role of the Risk Map of Cultural Heritage.Finally,based on the discus-sions of the durable change in the architectural conservation field after the Venice Charter,including the teaching in Milan School,the debate and re-definition of architectural conserva-tion and the advance definitions of conservation,prevention,maintenance and restoration in the 2004 National Code of Cultural Heritage and Landscape,it gives us an agenda for futuretrends of planned conservation with aims to conserve the material authenticity and promote.the co-evolutional strategy.展开更多
文摘Using the case study methodology, firm＇s competition behavior in strategic network and strategic ecosystems are analyzed. With the ecology view, there is consistency between strategic network and strategic ecosystem. Enterprise should pursue for suitable ecological niche to hold a strategic competitive power.
文摘In this paper, based on a class of multi-group epidemic models of SEIR type with bilinear incidences, we introduce a vaccination compartment, leading to multi-group SVEIR model. We establish that the global dynamics are completely determined by the basic reproduction number R0V which is defined by the spectral radius of the next generation matrix. Our proofs of global stability of the equilibria utilize a graph-theoretical approach to the method of Lyapunov functionals. Mathematical results suggest that vaccination is helpful for disease control by decreasing the basic reproduction number. However, there is a necessary condition for successful elimination of disease. If the time for the vaccines to obtain immunity or the possibility for them to be infected before acquiring immunity is neglected in each group, this condition will be satisfied and the disease can always be eradicated by suitable vaccination strategies. This may lead to over evaluation for the effect of vaccination.
文摘This paper tells us a complex story on the historic evolution of preventive conser vation of architectural heritage in Italy.Firstly,it introduces Cesare Brandi's Theory of Resto ration,pointing out the peculiar sense of the word Restoration in Brandi's system other than the common sense in the international discourse,the limits of Brandi's theory to architectural conservation and his prophecy on preventive restoration.Then it talks about the differentframework and practices of preventive conservation in the field of built heritage compared to the museum sector,the milestone of Giovanni Urbani's pilot project on programmed conser.vation and the leading role of the Risk Map of Cultural Heritage.Finally,based on the discus-sions of the durable change in the architectural conservation field after the Venice Charter,including the teaching in Milan School,the debate and re-definition of architectural conserva-tion and the advance definitions of conservation,prevention,maintenance and restoration in the 2004 National Code of Cultural Heritage and Landscape,it gives us an agenda for futuretrends of planned conservation with aims to conserve the material authenticity and promote.the co-evolutional strategy.
