动态能力对双元创新协同性的影响:环境竞争性的调节作用

双元创新的协同性及其前因变量是企业实施双元创新时必须考虑的重要问题,也是国内外学者研究较少的前沿课题之一。文章首先通过文献回顾与理论分析,探讨了动态能力与双元创新协同性之间的因果关系,以及环境竞争性对上述关系的调节效应,提出了相应的研究假设和概念模型,然后通过问卷调查和统计分析,对上述研究假设和概念模型进行了实证检验。检验结果表明:动态能力与双元创新平衡性、互补性和协同性均正相关;动态能力的重组转型能力维度与双元创新平衡性、互补性均正相关;环境竞争性在动态能力与双元创新协同性、动态能力与双元创新平衡性关系中起到正向调节作用。     

GLOBAL ANALYSIS OF SIS EPIDEMIC MODEL WITH A SIMPLE VACCINATION AND MULTIPLE ENDEMIC EQUILIBRIA

An SIS epidemic model with a simple vaccination is investigated in this article. The efficiency of vaccine, the disease-related death rate and population dynamics are also considered in this model. The authors find two threshold R0 and Rc (Rc may not exist). There is a unique endemic equilibrium for R0 > 1 or Rc = R0; there are two endemic equilibria for Rc < R0 < 1; and there is no endemic equilibrium for R0 < Rc < 1. When Rc exists, there is a backward bifurcation from the disease-free equilibrium for R0 = 1. They analyze the stability of equilibria and obtain the globally dynamic behaviors of the model. The results acquired in this article show that an accurate estimation of the efficiency of vaccine is necessary to prevent and controll the spread of disease.