Immersive Virtual Environments can provide users with a sense of spatial presence and experience. But learners with Color Vision Deficiency cannot receive information entirely in the environments because they are difficult to distinguish some or all colors. This study selects learners with red-green color blindness as the sample, and designs three kinds of barrier-free Teaching Resources based on a color scheme and color contrast to explore their impacts on spatial cognition and learning experience. The experimental results show that the Color Adjusted Teaching Resources has significant differences both in learning satisfaction and technology acceptance, and the Contrast Adjusted Teaching Resources performs an important role in improving spatial cognition and technology acceptance. In addition, the Color and Contrast Adjusted Teaching Resources is significantly different from the Color Adjusted Teaching Resources in spatial cognition. Therefore, the findings indicated that the barrier-free color scheme and higher contrast of Teaching Resources can significantly improve spatial cognition, learning satisfaction, and technology acceptance of learners with red-green color blindness. To some extent, the research results can contribute to the design of barrier-free Teaching Resources about red-green color blindness.

Bridge demolition project involves a variety of factors, belonging to the category of multi-factor decision-making. How to choose a reasonable demolition scheme from a variety of schemes is a problem to be considered. This paper is to use multi-factor decision-making method to optimize and select bridge demolition scheme. Taking the formulation of a certain bridge demolition scheme in China as an example, this paper demonstrates in detail the process of optimization selection and design as well as the result of the bridge demolition scheme. AHP method is used to decompose each factor of bridge demolition to form a hierarchical structure. On this basis, TOPSIS method is used to calculate the proximity between each demolition scheme and the positive ideal solution. Finally, the bridge demolition scheme is selected according to the calculation value.