基于超网络的生态工业链动态均衡研究

Dynamic Equilibrium of Eco-industrial Chain Based on Supernetwork

通过分析生态工业链的结构,构建了将供应型企业、生产型企业、消费型企业及回收型企业耦合为一体的超网络模型。进而剖析了模型的影响因素,并通过量化这些因素和提出基本假设,运用变分不等式刻画了超网络模型中各层企业的行为和目标,得到了整个模型的动态均衡条件,给出了理论证明。在此基础上,结合动态均衡条件和KKT条件转换式,以贵港生态工业园的复合肥生态工业链为例,运用Lingo9.0和Matlab7.0进行模拟计算。结果表明,各层企业间契约履行率和操作技术参数与各层企业及整个生态工业链的利润率基本呈正比,而讨价还价能力值和交易损耗率与各层企业及整个生态工业链的利润率基本呈反比,计算结果与实际相符,验证了模型的有效性。

Eco-industrial chain is a complex system composed of multilayer enterprises,having different responsibilities at different layers,and exchanging multi-dimensional resources,such as raw material,information,and technology,with each other.In recent years,supernetwork,an effective tool to describe this kind of complex system with the characteristics of multi-layers,multi-attributes and multi-crieria,has been widely used in supply chain,knowledge management and biological fields.However,supernetwork has been used less in the field of eco-industrial chain.Although there are more and more studies on stability and equilibrium problems of eco-industrial chain,only a few of them have studied these problems from the perspective of supernetwork and variational inequalities.Variational inequalities have been widely used in the field of supply chain,but they mainly focus on solving static equilibrium problems and do not consider dynamic equilibrium problems caused by time factor.However,eco-industrial chain is a system of enterprise alliance that changes over time.In addition,enterprises in the eco-industrial chain have special targets of considering the environmental impact and unique influence factors of changes over time in order to operate stably.By treating enterprises as nodes,and coopetition relationships among enterprises with same layers as edges,this paper analyzes the operational process of eco-industrial chain and builds supplying enterprise networks,production enterprise networks,consumption enterprise networks,and recycling enterprise networks.These networks are integrated as a supernetwork according to their mapping relationships.Furthermore,the model＇ s influential factors,including transaction costs,penalty costs,operation technology profits and environmental costs,are analyzed by using economics theory.Dynamic equilibrium condition of the model is obtained and theoretical proof is provided through quantizing these factors.Some basic assumptions are proposed,discrete variahle of trading session is introduced,behaviors and targets of enterprises in each layer are depicted with variational inequalities.In addition,optimization models of profit maximization and environmental impact minimization are established by combining the standard weight function and value function.Lingo9.0 and Matlab7.0 are used in combination with dynamic equilibrium condition and transformation formula of KKT condition to mix program,simulate and calculate an eco-industrial chain which produces compound fertilizer in Guigang ecoindustrial park.The results show that contract compliance rates and operation technology parameters are positively correlated with profit margins of both enterprises in each layer and eco-industrial chain.However,bargaining power values and loss ratios in trade are just the opposite.The result corresponds with actual problems,and the validity of the model is verified.Therefore,enterprises of each layer in an ecoindustrial chain should make efforts to reduce the bargaining power and loss ratios in trade,increase the contract compliance rates and operation technology level,promote the transformation and upgrading of industrial structure,as well as create and maintain the good reputation and cooperation environment.Doing so enables these enterprises to maximize profit margins of their own and the whole ecoindustrial chain,maintain the stability of eco-industria1l chain and promote the sustainable development of society.