## 4 Case Validation and Results  
Previous studies have indicated that the design of transportation products puts more emphasis on PI. Whether it is cars or motorcycles, brands such as BMW, Buick, and Harley-Davidson have all received attention in the field of academic research [21, 22]. This section selects a Chinese brand of female E-mopeds as an example to verify the feasibility of the proposed method. At present, the brand's products have initially established the PI design. However, since early E-moped users were predominantly male, the product form designs were mainly led by male aesthetics. Currently, the female E-mopeds on sale only meet the aesthetic demands through modifications such as color, painting, structural lightweighting, and accessories, rather than starting from the initial CRs, as shown in Figure 6.  
Since females focus more on emotional needs when making purchasing decisions, integrating feminine emotional demands into product form design has become a key element of the design process [45]. It is a significant challenge for SMEs to design a product form that retains PI while meeting female CRs efficiently and accurately with limited resources available. To achieve this goal, the process is specifically divided into the following three phases:  
_The first phase: Generation of conceptual alternatives for PI form design_  
_Step 1: Defining PI characteristics._ The form of E-mopeds has two different riding postures: sitting-style and straddle-style. The brand's mainstream sitting-style product was selected by this study. Previous studies on structurally similar vehicles such as motorcycles or mopeds had primarily used the side view as the main perspective for research [46]. Therefore, we chose the side view as the research perspective and collected 25 product images, online and offline. An expert team of five experts, including E-moped specialists, brand strategists, and industrial designers, utilized the KJ method to select a representative sample (model NQi). Eight form design features were extracted and coded A-H, as shown in Figure 7.  
Using Photoshop, the images of 25 products were refined to eliminate color and pattern distractions. The MA and Delphi methods were used by experts to identify 3 main PI form elements that influence the product design: (1) Front Cover: an arrow-shaped front cover that extends to the sides (Figure 8a). (2) Seat: the seat contour is more rectangular, avoiding free curves (Figure 8b). (3) Side Cover: the side bottom cover and side body cover are polygonal in shape, divided into separate and integrated styles (Figure 8c,d). Figure 6: Three types of modifications for female E-mopeds. _Step 2: Generating conceptual sketch alternatives._ Midjourney cannot effectively recognize the PI form elements of images. First, the PI area of the product image was manually marked with color blocks for pre-processing and then input into Midjourney for training. Taking one side body cover as an example, the pre-trained image obtained after manual processing was shown in Figure 9, where the red area indicated the PI form area for AI recognition training. Second, the pre-trained images were input into Midjourney to obtain image links, and then one of the 8 deductive rule prompts was input for image generation. After several iterations and selections, the concept sketches were obtained. Taking an iteration-generated interface as an example, the U button and V button were used to select and fine-tune the images for the next round of generation. At the same time, the prompts can also be modified through the bottom dialogue box to obtain other alternatives of PI, as shown in Figure 10.  
Figure 8: Three main PI form elements. Figure 7: The form design features of the E-moped. Figure 9: Pre-training image of the side body cover.