This study was undertaken to achieve a high bleaching efficacy with plasma, through longer application and reparative bleaching processes, by different shade evaluation methods. Extracted human teeth were divided into 6 groups (n=10). All teeth were treated in pairs. Low concentration of 15% carbamide peroxide (CP) was applied, with and without plasma, for 10, 20, and 30-min tooth bleaching, respectively. The bleaching procedure was repeated once daily for four days. The teeth were maintained in a moist environment provided by artificial saliva. The Vitapan Classical shade guide and Commission Internationale de L’Eclairage (CIELAB) color system were collectively used to measure the bleaching efficacy. Color evaluation was statistically analyzed using Student t-test and one-way analysis of variance (ANOVA) complemented by Tukey’s test. Combining the plasma with 15% CP showed significantly greater color changes compared to bleaching without plasma (p<0.05). A high bleaching efficacy with plasma is proportional to the repetitive application and the treatment time. A 30-min application with plasma provided the best bleaching. Repetitive bleaching showed lower probability of color relapse of the bleached tooth. The color change by shade guide correlated with the changes in CIELAB color system. A value of 1 color change units (CCU) conversion factor for overall color change (ΔE) values comparisons was 3.724 values. The two measuring methods provide a more accurate correspondence of color change. The repetitive and longer application for tooth bleaching, combined with plasma, has a strong bleaching effect and produces whiter teeth.

본 논문에서는 H.264/AVC 비디오 코덱에 다차원 변환을 적용하여 높은 압축 성능을 갖는 비디오 부호화 방법을 제안한다. 다차원 변환은 4×4 변환의 장점과 높은 공간적 압축도를 갖는 변환 방법이다. 본 논문에서는 효율적인 변환을 위해 블록모드에 따라 동일한 방향성을 가진 영역을 설정하는 방법을 소개한다. 또한 다차원 변환에 맞는 변환계수 비용 함수를 제안하여 개선된 결과를 얻을 수 있다. 실험을 통해 제안하는 비디오 부호화기는 H.264/AVC에 비하여 BD-RATE 측면에서 약 6.14% 개선된 성능을 보였다.

Background : An important feature of the nutrient solution is that they affect not only the growth but also quality of crops by changing nutrient uptake, especially due to changes of EC in nutrient solution. This study was carried out to investigate effect of EC in nutrient solution on growth and ginsenoside of ginseng. Methods and Results : EC in nutrient solution was controlled with 0.68, 0.84, 1.23, 1.41 dS/m. The root weight of ginseng treated by low EC levels in nutrient solution was higher during the initial of growth. However, the higher EC levels, the more increased the change rate of root weight from the initial to the middle of growth. The highest amount of ginsenoside was changed by growth period. Although the total amount of ginsenoside in root is highest treated by EC 0.68 dS/m at 45 days after treatment. the total amount of ginsenoside in root is highest treated by EC 1.23 dS/m at 135 days after treatment. Conclusions : EC in nutrient solution should to be controlled depending on the stage of growth and the part of use, i.e. root and leaves, when ginseng is cultivated through nutri-culture.

Background : Boron (B) is an essential element required for the growth of plant. It has a narrow range of optimal concentration from minimum to maximum thresholds than other micro-elements. The study was carried out to investigate to the influence of B excess concentrations on physiological disorder of leaf, growth and mineral concentration of ginseng to obtain basic information for physiological disorder diagnose. Methods and Results : The ginseng cultivar ‘Gumpoong’ was cultivated by hydroponic system for 2 months. The toxicity symptoms which ginseng leaves were curved downwardly and induced to chlorosis after beginning to dry the edge appeared on leaves more than 30 ppm compared to the control(3 ppm). The growth of ginseng was more decreased with higher B concentration. Mn uptake was also decreased as B concentration increased. It was found that B excess hindered the growth of ginseng and was reversely related to Mn uptake. Conclusions : More than B 30 ppm can negatively affect growth and mineral uptake. Consequently, B excess can occur physiological disorder of ginseng.