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This study proposes a new algorithm that can render a realistic image of an automotive rear lamp using the backward ray tracing method. To produce a realistic image similar to that perceived by the human eye, the physical transformation procedures of light energy are traced by a spectral interaction definition. The incident light energy at the eye point estimated by a ray tracing algorithm is represented by XYZ tri-stimulus values, which are then converted into RGB values considering the particular display device. A more effective form of light source modeling than the Monte-Carlo integration method is also applied for accurate simulation. Finally, comparisons of traced results and real measurements are performed in terms of the spectral distribution, image detail, and visual experiments.

This study proposes a new calculation method for generating real nighttime lamp-lit images. In order to improve the color appearance in the prediction of a nighttime lamp-lighted scene, the lamp-lit image is synthesized based on spectral distribution using the estimated local spectral distribution of the headlamps and the surface reflectance of every object. The principal component analysis method is introduced to estimate the surface color of an object, and the local spectral distribution of the headlamps is calculated based on the illuminance data and spectral distribution of the illuminating headlamps. HID and halogen lamps are utilized to create beam patterns and captured road scenes are used as background images to simulate actual headlamp-lit images on a monitor. As a result, the reproduced images presented a color appearance that was very close to a real nighttime road image illuminated by single and multiple headlamps

In this study, the mass of THC is reduced almost 40 percent with spark timing ATDC 7.8CA during 15 seconds from engine start in phase 1 LA4 mode, comparison with TDC 2.8CA (Figure 1, Table 3). One of the reason of HC reduction in vehicle test is reduction of raw THC concentration before CCC (Closed Coupled Catalyst) which is 36% lower level (Figure 3, Table 3). The other reason is that the LOT (Light Off Time) of catalyst is shortened from 34 seconds to below 20 seconds (Figure 7, Table 3). As the spark timing is retarded with same intake air quantity and same RPM, BMEP is reduced (Equation (3), Figure 9). Therefore in order to operate in an idle RPM in vehicle, the mass of intake air should be increased (Figure 5). So a catalyst is heated in shorter period.