系统工程理论与实践
繫統工程理論與實踐
계통공정이론여실천
Systems Engineering—Theory & Practice
2006年
5期
111~116
,共null页
近海 水质 组合预测 log-logistic概率分布
近海 水質 組閤預測 log-logistic概率分佈
근해 수질 조합예측 log-logistic개솔분포
coastal marine; water quality; integrated prediction; log-logistic probability distribution
通过多种预测方法的综合运用,提出一种依据环境监测数据的近海水质组合预测方法,力求在降低计算难度的同时,提高预测精度.首先,依据入海水体的情况,采用BP神经网络法对近海水质进行因果型预测,预测平均误差为26.46%;其次,采用傅立叶8次级数对近海水质历史数据进行拟合,并将其延伸对近海水质进行类比型预测,平均误差为38.33%;最后,确定近海水质数据符合log-logistic的概率密度函数,提出将上述两种预测结果的概率密度作为其组合权重的近海水质组合预测方法,平均误差降低为21.20%.应用表明,该组合预测方法避免了机理性研究对众多基础数据的要求,原理简单、实用性强,能够为环境管理提供决策支持.
通過多種預測方法的綜閤運用,提齣一種依據環境鑑測數據的近海水質組閤預測方法,力求在降低計算難度的同時,提高預測精度.首先,依據入海水體的情況,採用BP神經網絡法對近海水質進行因果型預測,預測平均誤差為26.46%;其次,採用傅立葉8次級數對近海水質歷史數據進行擬閤,併將其延伸對近海水質進行類比型預測,平均誤差為38.33%;最後,確定近海水質數據符閤log-logistic的概率密度函數,提齣將上述兩種預測結果的概率密度作為其組閤權重的近海水質組閤預測方法,平均誤差降低為21.20%.應用錶明,該組閤預測方法避免瞭機理性研究對衆多基礎數據的要求,原理簡單、實用性彊,能夠為環境管理提供決策支持.
통과다충예측방법적종합운용,제출일충의거배경감측수거적근해수질조합예측방법,력구재강저계산난도적동시,제고예측정도.수선,의거입해수체적정황,채용BP신경망락법대근해수질진행인과형예측,예측평균오차위26.46%;기차,채용부립협8차급수대근해수질역사수거진행의합,병장기연신대근해수질진행류비형예측,평균오차위38.33%;최후,학정근해수질수거부합log-logistic적개솔밀도함수,제출장상술량충예측결과적개솔밀도작위기조합권중적근해수질조합예측방법,평균오차강저위21.20%.응용표명,해조합예측방법피면료궤이성연구대음다기출수거적요구,원리간단、실용성강,능구위배경관리제공결책지지.
Through the using of different prediction methods, a new integrated prediction model for coastal water quality based on monitoring data was proposed, which aimed to reducing calculation difficulty and prediction errors. Firstly, the cause-effect prediction was taken using BP NN ( back-propagation neural network), whose inputs were data about the incoming water. The average prediction error of this method was 26.46 %. Secondly, the monitoring data serial of each monitoring point was fitted by Fourier serial, after which the fitted Fourier serial was also used for prediction and the error was 38.33%. Finally, the integrated prediction was taken based on the above two prediction results, whose weights were calculated by its log-logistic probability density and average prediction error was reduced to 21.20% . Through application it could be found that the extreme demand on basic data in mechanism studies could be avoided, which made the method in this paper simple, practicable and could be the decision support for environmental management.