The invention provides a method for improving release, on a surface, of a fragrance from an entrapment structure of at least one fragrance oil and at least one entrapment material. One respective hydraulic motor for a drive train is provided per respective right or left vehicle side. Thus, the quality of the signal is better preserved since the larger effective area fiber reduces maximum optical signal density thereby reducing non-linear degradations on signal quality. For example, the washing unit operation can be modified to provide a contacting step at an increased time and temperature, and adding components such as calcium chloride and L-cysteine to an aqueous solution used for the contacting. A ratio of the number of feature parameters to the total number of keywords is compared with a preset threshold, and if the ratio is greater than or equal to the preset threshold, it is determined that a flood attack occurs.