Development of the FCM-ANFIS wave forecast model with an input of wind velocity at multi points
|關鍵字:||適應性類神經模式;波浪推算;多點風速;FCM群集分析;adaptive neuro-fuzzy models;wave forecasting;multi-point winds;fuzzy c means|
A FCM-ANFIS model with fast and concise wave calculation was developed for the safety of marine actions and coastal engineering. The algorithm of fuzzy C-means (FCM) was applied to data cluster analysis on the calculated data of wind velocity using the ARW wind model and on the observed data at the offshore observation pole of the Taipei harbor for 2012. Adaptive neuro-fuzzy inference systems (ANFIS) was used to establish the relationship between the clustered wind data and the corresponding wave heights. The proposed FCM-ANFIS model was verified to have better simulation on wave heights than the ANFIS model or the empirical model. The small deviations of the calculated data of wind velocity from the observations were evaluated by low bias and mean root of squared error and high vector correlation of 0.7922. The models with an input of calculated wind data or observations have equivalent simulation on wave heights. The results indicate that the calculated data of wind velocity are applicable for the input of FCM-ANFIS model instead of observed wind velocity. The calculated data of wind velocity at outer positions in the semi-cardinal directions around the observation pole by a distance of 25 km and 50 km were added in the inputs of the original FCM-ANFIS model to make a new multi-input FCM-ANFIS model. The multi-point FCM-ANFIS model has better simulation than the single-point FCM-FNFIS model. Specially, the best multi-input FCM-ANFIS (u,v) model has the highest R2 of 0.70 and the lowest RMSE of 0.31m among all assessed models. The promotion is 7% in R2 and 11% in RMSE compared with the single-point FCM-ANFIS (u,v) model. The calculated north western winds have stronger relation with the wave heights at the observation pole than other directions and give an advantage over the FCM-ANFIS model for wave calculations.
|Appears in Collections:||Thesis|