PURPOSES : The impact performance of flexible barrier system such as structural response, vehicular motion and occupant safety vary depending on the impact point. Thus, to properly evaluate the performance of a flexible barrier system, impact should be made to a point which will lead to the worst possible results. This point is called the Critical Impact Point (CIP). This paper presents the way to determine the CIP for a SB2 class flexible barrier system which is consisted of Thrie-Beam rail and circular hollow tube post of 2m span. METHODS: Barrier VII simulations were made for impact points; Case 1 at a post, Case 2 at 1/3 span downstream from a post, Case 3 at middle of the span, Case 4 at 2/3 span downstream from a post. For the structural performance (deflections), impact simulation of 8000kg-65km/h-15degree was used, and for vehicle motion and occupant safety, simulation of 1300kg-80km/h-20degree impact was made and analysed. RESULTS: Case 1 gave the largest dynamic deflection of 75.72cm and also gave the largest snag value of 44.3cm. Occupant safety and exit angle of the vehicle after the impact were not sensitive to the impact point and were all below the allowable limit. CONCLUSIONS : For the SB2 class flexible barrier system's CIP can be regarded as a post which is sufficiently away from the end of Length of Need in order to avoid the end-effect of the barrier system. It can be more economic in the long run because the normal concrete pavement material is likely to cost more due to higher probability of maintenance and repair and higher social cost due to traffic accident, etc.

Retinoic acid plays an important role in the regulation of cell growth and differentiation. In our present study, we evaluated the effects of all-trans retinoic acid (RA) on cell proliferation and on the cell cycle regulation of human gingival fibroblasts (HGFs). Cell proliferation was assessed using the MTT assay. Cell cycle analysis was performed by flow cytometry, and cell cycle regulatory proteins were determined by western blot. Cell proliferation was increased in the presence of a 0.1 nM to 1μM RA dose range, and maximal growth stimulation was observed in cells exposed to 1 nM of RA. Exposure of HGFs to 1 nM of RA resulted in an augmented cell cycle progression. To elucidate the molecular mechanisms underlying cell cycle regulation by RA, we measured the intracellular levels of major cell cycle regulatory proteins. The levels of cyclin E and cyclin-dependent kinase (CDK) 2 were found to be increased in HGFs following 1 nM of RA treatment. However, the levels of cyclin D, CDK 4, and CDK 6 were unchanged under these conditions. Also after exposure to 1 nM of RA, the protein levels of p21 WAF1/CIP1 and p16 INK4A were decreased in HGFs compared with the control group, but the levels of p53 and pRb were similar between treated and untreated cells. These results suggest that RA increases cell proliferation and cell cycle progression in HGFs via increased cellular levels of cyclin E and CDK 2, and decreased cellular levels of p21 WAF1/CIP1 and p16 INK4A.

국제감자연구소(International Potato Center:CIP)는 국제농업 자문그룹 산하의 국제농업연구센터 중의 한 기관으로 종자은행을 운영하여 페루 원산인 감자와 고구마 및 마카, 야콘 등 안데스 뿌리작물을 중심으로 다양한 유전자원을 보존하고 있다. 1. 총 257종 16,762점의 유전자원을 보존하고 있는데(2010년 1월 기준), 감자가 148종 7,180점(42.8%), 고구마가 68종8,026점(47.9%)로 세계에서 가장 많이 보존하고 있고, 기타 안데스뿌리작물 9작물 41종, 1,556점(9.3%)을 보존하고 있다. 2. 감자의 경우 종자, 괴경(tuber), 조직배양(in-vitro) 및 식물표본의 형태로 보존한다. 3. 중기저장고(온도 4oC, 습도는 30~40%)는 종자를 10년간 보존하고, 장기저장은 -20oC에 30년 이상 저장을 목표로한다. 식물표본은 감자에 한해서 총 195종 25,000점을 보존하고 있다. 4. 종자의 경우는 3년마다 발아율을 조사하여 60%미만 발아율을 보이는 자원은 증식하게 되고 영양체는 조직배양이나 초저온으로 동결 보존한다. 5. 작물별로 년 300점 정도의 유전자원을 포장에 전개하여 농업적 형질과 식품적 기능성 형질에 대한 특성평가를 하고 분자생물학적 방법을 이용하여 중복성과 진위성 검정을 실시하고 있다 6. 유전자원정보화시스템(germplasm database)에 유전자원을 정보화하고 분양신청이 가능하도록 홈페이지에 공개한다. 7. 분양은 품종육성 등 연구목적의 경우 무상분양을 원칙으로 하며, 분양시 식량농업식물유전자원국제조약(International Treaty on Plant Genetic Resources for Food and Agriculture: ITPGRFA)의 다자체제에 따른 식물유전자원분양계약서(Standard Material Transfer Agreement:SMTA)를 작성하고 그 결과를 데이터베이스에 등록하여 공개한다. 2007년 기준으로 총 153개 국가에 103,061점을 분양하였다.

염색폐수처리를 위하여 피페라진, 메타페닐렌디아미, 트리메소일 클로라이드를 이용하여 계면중합법으로 폴리아마이드계 나노분리막과 폴리아마이드계 역삼투막을 제조하였으며, 이들을 오스모닉스사로부터 구입한 역삼투막의 투과특성과 비교하였다. 이들의 기본 분리투과특성 조사를 위하여 PEG 600, Na2SO4, NaCl 수용액을 이용하였으며, 제조된 분리막들은 전형적인 나노복합막과 저압용 역삼투막의 특성을 나타내었다. 제조된 이들 분리막들을 이용하여 국내 염료 제조업체인 (주)경인양행으로부터 공급된 실제 염색폐수를 처리하였으며, 이때 이들의 분리투과특성을 살펴보았다. 또한 분리막을 이용한 폐수처리 시 발생되는 분리막 오염을 제거하기 위하여 일정시간마다 CIP를 실시하였다. 이때 3종류의 서로 다른 화학세정제를 사용하였으며, 이들의 세척성능을 살펴보았다.

Intensive technological research on the Dry-bag CIP equipment was carried out to improve the dimensional accuracy and the productivity. The rubber mold design technology using FEM simulation during pressing was introduced, in order to achieve higher dimensional preciseness, and criteria for the selection of the In-line type or Off-line type, were established based on the powder flowability index proposed by Carr. Based on these research results, high productivity Off-line Dry-bag CIP equipment, which can realize good dimensional accuracy with high productivity, was developed even for non-granulated powders with poor packing density.

It is well known that the imbalance between epithelial cell growth and inhibitor factors may cause human epithelial cancer. Over-expression of the epidermal growth factor receptor(EGFR) has been implicated in the development of oral squamous cell carcinoma. ZD1839 inhibits selectively the EGFR tyrosine kinase activity and is clinically used for cancer patients. However the mechanisms by which it exerts its anti-tumor activity remains unclear. This study attempted to determine the mechanisms underlying the effects of ZD1839 on the cellular level and to characterize the effects of ZD1839 with regard to human oral squamous cell carcinoma(OSCC) cell growth. The YD-10B and YD-38 cell lines established from OSCC in the department of Oral Pathology, Yonsei University College of Dentistry and ZD1839(Iressa) were used for this study. The inhibition of cell proliferation induced by ZD1839 was reversible and the lowest dose of ZD1839 that produced statistically significant growth inhibition in YD cell lines were 0.1 μM. The delay in cell cycle progression was induced by 0.1 μM of ZD1839 treatment after 24 hr. This reduction in cell proliferation and cell cycle delay were associated with up-regulation of the cyclin dependent kinase inhibitor(CDKI), P21CIP1/WAF1 and P27KIP1. Reduced expression of cyclin D1 was also observed after treatment with ZD 1839 to YD-38 cells but not to YD-38. The present results suggest that the antiproliferative effects of ZD1839, in vitro was associated with degradation of cyclin D1, which may be used as a possible indicator of a high cell sensitivity to ZD1839.

In this study, experiments to evaluate concrete breakout capacity of anchor under dynamic shear loading were performed. The cast-in-place anchors without reinforcement were prepared for dynamic and static loading tests. Three specimens were tested for dynamic tests and one specimen for static test. It was found from the tests that the concrete breakout capacity of anchors without reinforcement under dynamic loading was about 6% higher than static loading.

본 논문에서는 인터넷환경에서 증가하는 인터넷게임의 바이러스/웜의 공격에 의한 침해사고 발생시 정의되어야 할 정보와 이를 활용한 대량 트래픽을 발생시키는 탐지하는 방안을 제안하였다. 이에 따라 인터넷 게임 사고대응시스템에서의 자동화된 역추적 방안에 대한 설계와 기능에 대한 개념을 제시한다.

The purpose of this study is to focus on the townscape of Daegu based on the urban characteristics of the landscape cognition and images captured by citizens. The analysis was performed by the data obtained from questionnaires and interviews. This study methods were deals the cognition characteristics, landmark landscape, visual preference landscape, image and satisfaction. The results are summarized as follows: 1.The orders of cognition landscapes were estimated Apple〉Weather〉Texture〉Mt.Palgong〉Daegu Tower〉Pretty Girl〉Mt. Apsan〉Dalsung Park〉Conservative〉Dongsung Road, etc. That is constructed Nonphysical elements(62.0%) and Physical elements(38.0%) 2.The orders of representative landscape(Landmark) in city were estimated Mt.Palgong〉Daegu Tower〉Gat Rock〉Mt.Apsan〉Dalsung Park, etc. As a whole middle and old people(over 30gen) preferenced as a history landscape or natural landscape, but youth people(10-20gen) preferenced as visible and interesting artifical places. 3.While the positive attitudes for the image of city were traditional(3.30), intimacy(3.58), and rest(2.90), the negative attitudes were unnewly(2.34), closing(2.37) and narrow(2.40). Also total satisfaction for that was estimated 5.51. 4.Psychological factors, related to the satisfaction of the image of city were composed of four factors, individuality character, pleasure character, amenity character, formation character. And the presumption formula of satisfaction was: Satisfaction = 5.477 + 0.752(Individuality) + 0.470(Pleasure) +0.413(Amenity) +0.241(Formation)