Robust Logistic Network Design Of Fruit And Vegetables Under Demand Uncertainty

Fruit and vegetables of high nutritional value,low fat content,has always been a necessary product on the consumer's table.As the population grows,food production must expand to meet growing demand and food has to move efficiently from producing to consuming regions.Fruit and vegetables belong to a cold chain of goods,with the general nature of cold chain goods,that is,the transport time and storage technology has a higher requirement.The establishment of a reasonable logistics network system is necessary for the timely response to consumer demand for fruits and vegetables and reducing the loss of fruits and vegetables.The logistics center occupies an important position in the logistics network system,and if the logistics center location is not scientific,it may cause huge economic losses.So the scientific selection of fruits and vegetables logistics center location is very important,and it is necessary to establish a set of perfect logistics network system.The construction cost of fruit and vegetables logistics center is high,and the use period is long,which has a profound impact on the location decision.Logistics network model in the traditional supposes that all the parameters are determined,but in the actual operation of logistics system,consumer demand is constantly changing,so the traditional model is no longer suitable for the logistics network.To solve this problem,this paper builds the robust optimization model of the demand certainty and demand uncertainty,and studies the logistics network of fruits and vegetables.The specific research contents are as follows:First of all,analyze the fruit and vegetable product characteristics and logistics characteristics,sum up the fruits and vegetables logistics network design factors,put forward the cause of the uncertainty of the demand for fruits and vegetables.The concept and basic model of logistics network planning and robust optimization are summarized.Secondly,considering the consumer demand is uncertain,on condition that the location factors are known,the robust optimization model is established for the minimum cost of the model.In this model,the effects of fruit and vegetables' wastage for fruits and vegetables logistics network location scheduling is considered.Robust method is used to deal with uncertain demand parameters,and the robustness of the solution is controlled by the deviation of the control parameter.A numerical example is given to verify the validity of the model.It is analyzed from three aspects: the influence of demand uncertainty on the location and scheduling of logistics network system,the robustness of the solution,the influence of the control parameters and disturbance coefficient on the cost.Finally,on the basis of considering the minimum cost goal,the goal of carbon emission is added,and the two goals of minimizing the logistics cost and the minimu m carbon emissions are considered,and a multi-objective robust optimization model is established.To eliminate the difference of the two sub target units,the multi objective programming is transformed into a single objective programming by using the linear weighting method,and the model is solved by using the Lingo optimization software.The location results,path selection and path adjustment are obtained by calculating the weight,uncertainty and confidence level.At the same time,the total cost and carbon emissions of different uncertain and confidence level were compared and analyzed.