본 논문에서는 향상된 가시성 검사를 수행하여 기존의 중-텍스처링 구조에 비하여 데이터 전송량 및 깊이 캐쉬의 셀 면적을 감소시킨 픽셀 파이프라인 구조를 제시하였다. 제안하는 구조는 인접한 픽셀들 간의 가시성이 동일할 확률이 높다는 점을 이용하여 한 번의 가시성 검사만 수행하면서도 중-텍스처링 구조와 대등한 성능을 보이는 픽셀 파이프라인 구조이다. 실험결과, 제안하는 구조는 중-텍스처링 구조에 근접하는 성능을 보이면서도 깊이 캐쉬의 전송량은 평균 25%, 깊이 캐쉬의 면적은 약 40%가 감소하였다.

Visibility reduction is a barometer of air pollution, which people can notice easily. First of all, we need to measure quantified visibility continuously in order to examine visibility reduction. Prevailing visibility is not practical to measure visibility depending on observer's expertness. Scattering visibility using Forward Scattering Meter (Belfort Visibility Sensor 6230) has been measured at Kwangan-Dong in Pusan and analysed since July, 1998. According to the analysis, the correlation coefficient(R) between prevailing visibility and scattering visibility was 0.7235. The visibility appeared that each frequency of poor visibility (under 6㎞) and good visibility(over 25㎞) was 10.6%, 9.7% on summertime in Pusan and the visibility range from 10km to 20km ranked high frequency as a half of whole ranges. The order of correlation coefficients between visibility and air pollutants are ranking CO, PM10 and NO2, that values are 0.5878, 0.5369, 0.5284 respectively. In meteorological factor, the case of poor visibility presented more weakly wind speed and higher relative humidity than the case of good visibility. The correlation coefficient between calculated visibility of multiple linear regression model and observed visibility was 0.7215. But the trend of calculated and observed visibility variation was similar with the exception of several good visibility cases.

After analyzing the correlation between air pollution and visibility, TSP and NO2 is responsible for poor visibility in Pusan. After analyzing the correlation between meteorological factors and visibility, general pattern of humidity has clear negative correlation. The variation of wind speed has a positive correlation. In order to investigate the cause of poor visibility in Pusan area, the Andersen sampler and PM-2.5 are used to collect and analyze aerosol. This study was carried out to monitor the visibility using Forward scattering meter and to find out the characteristics and the cause of good visibility case and poor visibility case by measuring and analyzing a variety of parameters, such as particle size distributions, chemical compositions, and meteorological conditions in Pusan. According to the analysis of intensive sampling, NO3-, NH4+ ion concentration increased together with the mass concentration around 0.5∼2.5㎛ approximately during the case of poor visibility. NH4NO3, NH4Cl, and NaCl were thought to be the major components of fine particles.

The Daechong dam is located nearby Chongju city, and the population alone in the Chongju- Chongwon area is over one half million. It is found that the number of days for fog occurrence after constructing the dam was much fewer than those before constructing it. It appears that the construction of a large dam did not cause to increase in the occurrence of fog in the Chongju area, and that was the increase due to topographical characteristics and wind direction. Low visibility in the Chongju-Chongwon area occurred frequently. In summer, Chongwon recorded more days of poor visibility than those observed at Chongju. It is thought that TSP. SO_2 and NO_2 were the main constituents of air pollutants causing the reduction in visibility. These air pollutants are produced by vehicles and industrial activities in the region.