intelligent database systems lab presenter : fen-rou ciou authors : hamdy k. elminir, yosry a....
DESCRIPTION
Intelligent Database Systems Lab Motivation For most of the locations all over Egypt the records of diffuse radiation in whatever scale are non-existent. In case that it exists, the quality of these records is not as good as it should be for most purposes and so an estimate of its values is desirable.TRANSCRIPT
Intelligent Database Systems Lab
Presenter : Fen-Rou Ciou
Authors : Hamdy K. Elminir, Yosry A. Azzam, Farag I. Younes
2007,ENERGY
Prediction of hourly and daily diffuse fraction using neural network, as
compared to linear regression models
Intelligent Database Systems Lab
OutlinesMotivationObjectivesMethodologyExperimentsConclusionsComments
Intelligent Database Systems Lab
Motivation• For most of the locations all over Egypt the
records of diffuse radiation in whatever scale are
non-existent.
• In case that it exists, the quality of these records
is not as good as it should be for most purposes
and so an estimate of its values is desirable.
Intelligent Database Systems Lab
Objectives• To achieve such a task, an artificial neural network
(ANN) model has been proposed to predict diffuse
fraction (KD) in hourly and daily scale.
Intelligent Database Systems Lab
Methodology
Intelligent Database Systems Lab
Methodology• It can predict the KD value in hourly and daily scales base
on KT and S / S0
• In hourly scale, the input layer has five individual inputs.
• In daily scale, the input layer has three input.
Intelligent Database Systems Lab
Experiments– In hourly scale
ANN Erbssandard error(SE) ≌4.18% ≌5.59%
R2 0.95-0.89 0.87-0.65
Correlation cofficient(r)
0.96 0.87
standard deviation(SD) less than 0.2MJ/m2
99.7% 71.7%
Intelligent Database Systems Lab
Experiments– In hourly scale
Cairo South Valley AswanMBE(MJ/m2)
0.16 – (-0.13)
0.14 – (-0.09)
0.02
RMSE 0.35 0.27 0.23
Correlation cofficient(r)
0.94 0.98 0.99
Intelligent Database Systems Lab
Experiments – In daily scaleGopinathan and Solar’s Model ANN’s Model
Intelligent Database Systems Lab
Experiments – In daily scaleGopinathan and Solar’s Model ANN’s Model
GS ANNMBE(MJ/m2)
-0.16 – (0.22)
-0.14 – (0.04)
RMSE 1.14 0.59
SE 5.96-2.51% 17.76-4.84%
Intelligent Database Systems Lab
Conclusions• These findings show that the neural network is more
suitable to predict diffuse fraction than the proposed
regression models at least for the Egyptian sites.
Intelligent Database Systems Lab
Comments• Advantages– Let me relearn statistics.
• Applications– Prediction diffuse fraction