Estimation of Reshaped Profile in Berm Breakwaters Using...

In the area of prediction of the reshaped profile of slopes, Popov (1960) [13] investigated the stable slopes in coastal area by means of physical modeling. The stability of reshaped profile in rubble mound breakwaters with rock or concrete cube armors was studied by Priest et al. (1964) [14]. Van der Meer (1992) released the first version of his computer software, named BREAKWAT [15], in order to predict the reshaped profile in berm breakwaters. According to the studies performed by Lykke Anderson (2006), Van der Meer (1992) method predicts the reshaped profile of dynamically stable berm breakwaters (H0T070) with acceptable accuracy. But for statically stable berm breakwaters (H0T070) BREAKWAT software predicts overestimated damage†¦show more content†¦M5 models are built by a divide-and-conquer method. M5 model tree algorithm splitting criterion is based on reduction in measured standard deviation of the class values that reaches a node. The standard deviation reduction ( ) is: (1) In eq.(1), T is the representative of each set of examples reaches a specific node; Ti is the subset of examples that have the ith outcome of the potential set; and sd is the standard deviation. Over elaborate structures are often produced in the division process by standard deviation reduction, so the pruning process will become necessary for the tree. Pruning method uses the expected estimated error of each node for each experimental data (Wang and Witten (1997)). After the pruning procedure, some discontinuities will be appeared in the neighboring leaves of the pruned tree. Thus, a smoothing procedure is necessary. Smoothing procedure was explained by Quinlan (1992). According to the experiments carried out by Wang and Witten (1997), smoothing substantially increases the accuracy of predictions (Zhang et al., 2007 [21]). 4. Governing Equations for Reshaping Parameters During the investigations on reshaped profiles from existing data and according to Van der Meer (1992) studies on reshaping profiles, it is concluded that, in under water part of the reshaped profile, the power function in form of y=ax-b fits properly to the