Based On The Situation Of Public Health Emergency System Dynamics Modeling Study

At the beginning of 2020,China and the whole world have experienced a very serious public health emergency,it is the most serious infectious disease event that China has experienced since the founding of the People’s Republic of China,It also awakens our awareness of public health emergencies.Properly treating public health emergencies and controlling their serious trend,the key is to take the emergency decision in time and make the prediction to the future direction of the event to make the next decision,this is also the focus of this paper:How to quickly make reasonable emergency decisions and make judgments about the direction of future events.If you want to make a reasonable emergency decision and judgment on an emergency,you need to have a certain understanding of the current event and then make corresponding responses.However,due to the high complexity and uncertainty of emergencies and the long duration of public health emergencies,For example,the COVID-19 outbreak in China lasted nearly four months before it was brought under control to a stable state,So it’s very difficult to find a very similar case in the original case to learn about emergency decisions and to predict the direction of events.And an event is not fixed in its entirety,according to life cycle theory,The event has the beginning period,the rising period,the outbreak period,the plateau period,and finally the disappearance,the same is true for public health emergencies,The number of people who get sick will go through different periods,and the number of people who get sick will increase at different rates.According to the fact that an event will include different scenarios in the whole process,this paper transforms the establishment of case database into the establishment of scenario database,break the event down into scenes,When a public health emergency occurs,the similarity is calculated according to the initial scenario and the scenario in the scenario database.Then according to the similar situation to match the emergency decision making.Selecting system dynamics to predict the location of public health emergencies,Because:(1).System dynamics can clarify the causal relationship between various variables and construct a reasonable variable causality diagram.(2).Can make systematic analysis of the whole event,master the overall situation of the event,and not omit elements.(3).The indicators can be quantitatively analyzed,the trend of the event can be quantitatively simulated,and the stage of the event can be explained with data,so as to be reasonable and scientific.The main contents of this paper are as follows:Build a public health emergency scenario database.The typical public health events were selected to construct the scenario database to ensure the calculation of scenario similarity.Scenarios are divided into three levels: dimensional-index-attribute.At the same time,according to the definition of public health emergency,the first layer and the second layer of retrieval are set,to simplify the workload of scenario similarity calculation.The dimension hierarchy of the selected case includes internal dimension,external dimension and emergency decision-making dimension;The index level is the important and main indexes that affect the development of the event under each dimension;The attribute of the index is the specific qualitative or quantitative division of the index and the evaluation criteria.After classifying the scenarios,the scenario database is constructed by summarizing the index attributes contained in each case.At the same time,the weight of each index attribute is determined according to the analytic hierarchy process,and the algorithm of scene similarity calculation is positioned as the nearest neighbor similarity algorithm.When the situation of the target case is highly similar to the situation in the scenario database,the emergency decision can be made by imitating the similar situation.Build the system dynamics model.The system dynamics model is constructed according to the important attribute of similarity calculation in the scene.Uncertain index attribute values can first be simulated according to the numerical value of similar scenarios,and then adjusted according to the actual situation if they are not suitable for the actual situation.Determining the quantitative value of each index attribute or calculating equation after the completion of the system dynamics model construction of the event.Finally,a classic outbreak of infectious disease event was selected,and the index elements of the initial situation were quantitatively determined and scored,carry out similarity calculation with the scene in the scene library to get the scene that is most similar to it,at the same time,the similarity was calculated with other non-communicable disease events,and it was found that the similarity value was too small,which proved that it was reasonable to carry out the first layer retrieval and the second layer retrieval,it saves the time of similarity calculation.The fuzzy value of the index is determined according to the similar situation,and then the numerical value is put into the system dynamics equation according to the actual situation to simulate the cumulative number of patients in the development stage and the actual existing number of patients,The results are similar to the real situation,which proves the feasibility of the model.