Buzz, squeak, rattle noise that are referred as BSR have become important part in vehicle's quality because vehicle NVH(noise vibration harshness) reduction technology of main parts like engine and drive-line has made great progress except BSR noise. BSR test is progressed by composing many road excitation power spectrum density(PSD) profiles into a composite PSD profile. Shakers which are input by composite PSD profile make time histories(time-acceleration data) by aggregate of a large number of harmonics related with composite PSD profile in general. But when only composite PSD profile is input to shaker, the time histories from shakers exhibits Gaussian distribution characteristics and can't reflect all road excitation PSD profiles. In this study, we search other studies that try to solve the problems occurring when a shaker is input only PSD profile and analyze time histories resulted from BSR test to check ways of shaker's operation.

Universal design is defined as the design process of products and environments usable by all people to the greatest extent possible, without the need for adaptation or specialized design. The benefits of universal design have been promoted primarily through illustrative ‘success stories’of public, residential and occupational environments and products. While case examples may be informative, they may unfortunately be limited in terms of generality to other designs or tasks. Therefore, design methods and criteria that can be applied systematically in a range of situations to encourage universal design are needed. In addition, the seven principles of universal design are intended to guide the design process. The principles provide a framework that allows a systematic evaluation of new or existing designs and assists in educating both designers and consumers about the characteristics of more usable products and environments. However, exactly how these principles are incorporated into the design process has beenleft up to the designer. Since the introduction of universal design, designers have become familiar with the principles of universal design, and they have developed many products based on universal design. However, the principles of universal design are qualitative, which means designers cannot quantitatively evaluate their designs. Some have worked to develop more systematic ways to evaluate products and environments by providing design guidelines for each of the principles. However, recommendations have not yet been made regarding how to integrate performance measures of universal design into the product design process before the product is mass produced. Furthermore, there are sets of requirements regarding each user group that has different age and ability. Consequently, there is an urgent need for design methods, based on a better understanding of age and ability related factors, which will lead to a universally designed product or environment. The authors have proposed the PSD (Preference Set-Based Design) method that can generate a ranged set of feasible solutions (i.e., robust and flexible solution set) instead of single point solution that satisfies changing sets of design targets. The objective of this paper is to develop a general method for systematically supporting the universal design process. This paper proposes the applicability of PSD method to universal design. Here, the proposed method is successfully illustrated with a universal design problem.

According to the measurements at Seoul Metro subway, the sound level at the time of subway arrival ranged from 77.0 to 92.5 dB(A). The highest level was 92.5 dB(A) at Line-1, and the lowest level was 77.0 dB(A) at Line-5. The sound level of departure ranged from the lowest level of 82.9 dB(A) at Line-5 and the highest level of 95 dB(A) at Line-1. The indoor sound level at subway ranged from the lowest level of 87.2 dB(A) (Line-6) to the highest value of 92.1 dB(A) (Line-1). The results of this study also showed that the sound level at subway platform with Platform Screen Door(PSD) showed 81.8 dB(A) but 89.1 dB(A) without PSD. The sound reduction effect of PSD showed 7.3 dB(A) at platform. Consequently, the sound level in Korean subway was found to exceed the standard set for the American Public Transportation Association (85dB(A)).