본 연구에서는 고속철도 강합성형 교통비 동적해석에 기반한 피로신뢰성평가 기법을 제시하고 동조질량감쇠기의 효과를 피로수명연장 측면에서 검토하였다. 피로 신뢰성 평가를 수행하기 위하여 S-N 곡선 및 선형누적손상이론을 이용하여 한계상태식을 설정하였다. 열차 속도와 교량 감쇠비의 불확실성을 고려하여 교량에 대한 반복적인 동적해석을 수행하고, 이 결과로부터 전체 교량수명동안에 교량이 받는 피로 손상도와 연관된 확률변수의 특성을 통계적으로 추정하였다. 최종적으로 결정된 확률변수와 한계상태식에 개선된 일계이차모멘트법(AFOSM)을 적용하여 피로 신뢰도 지수를 산정하였다. 40m 지간 강합성교량의 수치모사로부터 동조질량감쇠기 장착여부에 따라 피로 신뢰도 지수를 평가하고 그 결과를 제시하였다.

To investigate the modifying effect of Kwao Kreu, Pueraria mirifica (PM), we performed two kind of studies which are the non-surgical medium-term carcinogenicity study and the modulation of gap functional intercellular communication study. The first study, a non-surgical medium-term carcinogenicity bioassay was done to investigate the modifying effect of Kwao Kent, Pueraria mirifica (PM), a rejuvenating folk medicine from Thailand, on the male F344 rat liver. Specific pathogen free, male 6-week-old F344 rats were divided into ten groups. To induce hepatocarcinogenesis, those in all groups were given a single i.p. injection of DEN (200 mg/kg) and were received two i.p. injection of DGA (300 mg/kg) at the ends of weeks 2 and 5. Rats of group 3-6 were given sodium phenobarbital (PB 0.05 % in drink). A diet containing 10 mg/kg PM was given to group 2 during the post-initiation phase and to groups 4 and 5 during promotion and initiation phase, respectively. Group 6 was given the experimental diet alone throughout the experiment (8 weeks). Rats of group 7, 8, 9 and 10 were fed 1000 mg/kg PM in the same manner as group 2, 4, 5 and 6. All animals were sacrificed at 8 weeks after DEN administration. Result of the iimmunohistochemical staining of the glutathione S-transferase placental form (GST-p) indicated that the numbers and areas of the preneoplastic leisions were not significantly changed in all PM treatment group comparing to control group. A.Iso the numbers and areas of GST-p positive foci among group 7, 8, 9 and 10 were not significantly changed in comparing to control group. To study the effect of PM on the modulation of gap functional intercellular communication, the present study was performed scrape-loading dye transfer (SL/DT) assay in human keratinocytes. The results showed that PM could not modulate GJIC. These results indicate that Pueraria mirifzca may have no carcinogenic effects on experimental hepatocarcinogenesis in rats and gap functional intercellular communication in human keratinocyte.

Background : Glycyrrhiza uralensis Fischer is one of most important medicinal (Glycyrrhizae radix) herbs in traditional oriental medication and they are also important commercial products used worldwide in sweetening and flavoring. They contain the similar compounds, such as the triterpenoid saponins and flavonoids. Therefore, it is necessary to develop more efficient and sustainable methods for the production of G. uralensis Fischer and its medicinal constituents. This study was accomplished to investigate the effect of medium composition on in vitro propagation and plantlet regeneration from nodal explants of G. uralensis Fischer, and to establish a reliable protocol for micropropagation. Methods and Results : Young and actively growing stem segments were excised from adult plants of new cultivar ‘manju’. They were cut into a 1cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for two weeks. For shoot multiplication, one-node stem segments, approximately 1 ㎝ in length, were taken from in vitro derived shoots and subcultured. After four weeks of culture, the efficacy of each medium on shoot proliferation and growth was determined, and these shoots were transferred onto medium with different auxin hormones for rooting. Conclusion : After seven to ten days of culture, shoots began to emerge from axillary buds. They showed a vigorous growth and elongation in multiplication medium. During culture period, in vitro cultured plantlets showed significantly different responses to the respective medium with different plant growth regulators. Our experiments confirmed that in vitro growth and multiplication of palntlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

Background : Rehmannia glutinosa Libosch. is a perennial herb belonging to family Scrophulariaceae. It is also considered as a valuable medicinal plant in Asia including Korea, China and Japan because of its anti-anemic, anti-pyretic, anti-inflammatory and anti-senescence effects. Unfortunately it is difficult to propagate seeds due to poor seed viability and low propagation rate. Therefore, this plant is propagated vegetatively, but its vegetative propagation increases the incidence of virus infections in commercial fields, which can induce the production loss critically. So we have tried to compare the efficacy of virus elimination from R. glutinosa by thermotherapy, chemotherapy and shoot tip culture to find an optimal micropropagation for healthy and virus-free plant production. Methods and Results : For virus elimination, thermotherapy (heat treatment at 37℃ for 4 weeks), chemotherapy (addition into medium with antiviral agent) and shoot tip culture (meristem culture) were accomplished. After treatments, RT-PCR and ELISA methods were used for detection of three viruses including tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), broad bean wilt virus (BBWV). Conclusion : Efficiency of virus elimination was enhanced up to 59% in shoot tip culture, however, lowest at 5 - 10% after chemotherapy using antiviral agent (ribavirin). Most samples were verified to have multiple virus infection. From these results, we can suggest that combination treatment of shoot tip culture and thermotherapy may be more effective for the elimination of major viruses from R. glutinosa.

본 연구에서는 기상청에서 제공하는 국지예보모델(LDAPS)과 일본 기상청의 중규모모델(Meso-Scale Model, MSM)을 이용하여 태풍 및 정체 전선 등 3개의 강우사상과 남강댐 유역 내 산청 유역에 대해 강우 및 홍수 예측 정확도를 평가하고 비교․ 검토하였다. 강우예측 정확도 평가 결과, LDAPS와 MSM 모두 태풍 사상과 같은 광역적인 예측에 대해서는 예측 정확도가 높은 것으로 나타났으나, 정체전선과 같이 국지적으로 발생하는 강우사상의 경우 예측 오차가 많이 발생하는 것으로 나타났다. 홍수예측 정확도 평가 결과, 선행시간이 증가함에 따라 점점 예측 정확도가 향상되는 것을 확인할 수 있었으며, LDAPS와 MSM 모두 기상 및 수자원간의 연계를 통하여 강우 및 홍수 예측 분야에서의 활용 가능성을 확인할 수 있었다.