The Forecast And Early Warning Research About Soybean Market In China

After entering into the World Trade Organization, domestic farm produce market graduallymelt into the international market. Thus as one of the most important oil plants, the soybean alsoreceives the press from the international market. Consequently, it is an important meaning to buildthe forecast-warning system of soybean market for domestic soybean industry. In this paper,undergoing to survey the actuality of domestic soybean product, the output, demand and import ofthe soybean are forecasted using the method of the BPNN and the modified Logistic model. Twoimportant warning alert index of domestic soybean market, that is the dependence degree of thesoybean import and the increasing ratio of the price of the soybean, are built the forecast-warningmodel. In the end, suggestions corresponding to the early warning conclusion are given. Theresearch is consisted of the following aspects:1.In this paper, the production status of domestic soybean is analyzed. The recently changecases such as the unit production, the planting area and the total production of domestic soybean,are illustrated and the planting circs change of the soybean in domestic main soybean produce zoneis analyzed. On this base, the forecast model of the BPNN about the total production of the soybeanis bulit and the optimization analysis method of the degree of grey association is used whenselecting the number of the hidden nodes of the NN. As a result, the model of the NN with thestructure in 4-13-1 is produced and is correctly experimented by counting the degree of greyassociation between the hidden nodes and its output to estimate. Applying this model to forecast theunit production, the planting area and the total production of domestic soybean from 2006 to 2008,its result is revealed that the production status of domestic soybean keeps stable in the subsequentthree years.2.The status of the supply and demand of domestic soybean is analyzed. The recently changecases such as the supply quantum, the import quantum and the demand quantum, are illustratedassociated with external cases and the cause of the rapidly increasing of the demand quantum isdiscussed. About the forecast of the import quantum, the modified Logistic model is developed, inwhich the effect factor is added.Then the forecast model of the import quantum is provided,subsequently experimented and obtained a good effect. Using this model, the import quantum isforecasted from 2006 to 2008 and the modified Logistic model of the demand quantum isdeveloped by the same way. Its result is revealed that the import quantum keep gradually increasing and the demand quantum keeps stably increasing.3.Combined with the actual status of the soybean market,the import dependence degree andthe increasing ratio are referred as the warning alert indexes and the corresponding warning signindexs are selected. The foregoing, synchronous and lag properties of the warning alert indexes aredetermined and the indexes are predigested and selected.4.In the forecast-warning of the import dependence degree, three model are developed, whichare the warning signal lamp system model based on the composition simulation method,theforecast-warning system model based on the composition index and the multi-index tendencyextrapolation model of domestic soybean market. In the multi-index tendency extrapolation model,the multi-variable linear regression model is based on the foregoing warning alert index andmodified using the least square method with two steps. In the end, the warning degree is obtainedby comparing the advantage and disadvantage of three methods. Therefore, the import dependencedegrees highly warning and extensively highly warning fron 2006 to 2008.5.In the forecast-warning of the increasing ratio of the price of the soybean, the state-spacemethod is tried to modify, namely the state-space method is combined with the boom-cycle methodsuch that this way is more suitable.The forecast warning of the increasing ratio of the price from2006 to 2008 is realized by the model. The gentle, medium and medium areas with the increasingratio of the price of the soybean are operated in the subsequent three years.6.The suggestions and the ideas are advanced for constructing domestic future soybean marketwith the result of the forecast and the warning, and referred as the gist of the health development ofthe soybean market.