• Journal of Adhesion and Interface
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• v.6 no.2
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• pp.13-20
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• 2005

Interfacial shear strength (IFSS) of environmentally friendly natural fiber reinforced polymer composites plays a very important role in controlling the overall mechanical performance. The IFSS of various Ramie and Kenaf fibers/epoxy composites was evaluated using the combination of micromechanical test and nondestructive acoustic emission (AE) to find out optimal conditions for desirable final performance. Dynamic contact angle was measured for Ramie and Kenaf fibers and correlated the wettability properties with interfacial adhesion. Mechanical properties of Ramie and Kenaf fibers were investigated using single-fiber tensile test and analyzed statistically by both uni-and bimodal Weibull distributions. An influence of clamping effect on a real elongation for both Ramie and Kenaf fibers were evaluated as well. Two different microfailure modes, axial debonding and fibril fracture coming from fiber bundles and single fiber composites (SFC) were observed under tension and compression.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.2
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• pp.1-11
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• 1984

This aims of this study is to analyse the correlationship between traffic accident s and traffic characteristic variables in at-grade intersections of urban area, to build up an accident forecasting model and to propose an evaluation method of hazardous at-grade intersections. The accident forecasting model is formulated by the use of residual indexes that is selected by principal component analysis and its statistical significance is tested by step-wise regression analysis. Effective countermeasures for safety can be established on the basis of identifying high accident intersections, because the validity of this model was examined and found to coincide with real world situations.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.429-434
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• 2000

Isolated protoplasts from ginseng (Panax ginseng C. A. Meyer) callus tissue were cultured in modified MS media supplemented with various concentrations of dimethylsulfoxide (DMSO). The cell wall regeneration rate and cell division efficiency of the protoplasts were increased significantly by 1% DMSO treatment. However, there was no difference in the viability of protoplasts between the DMSO treatment and non-treatment. Transmission electron microscopy revealed that the microtubules were oriented in parallel manner to the plasmalemma after 3 days of culture in medium with 1% DMSO. Further, interconnected cellulose microfibrils were observed on the outer surface of the 3-day-cultured protoplasts by scanning electron microscopy These structures shown by electron microscopy were not observed in protoplasts cultured on DMSO-free media. This studies indicates that DMSO supplemented in culture media seemed to stimulate the cell wall regeneration and cell divisions of protoplasts by forming microtubule organizing centers (MTOC).

• Proceedings of The Korean Society of Health Promotion Conference
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• 1999.07a
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• pp.9-36
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• 1999

21C기를 맞이하면서 미국의 보건소가 당면한 과제는 시민들을 상해질병에서 보호하고 예방하는 것이다. 금세기 초 남녀 평균수명은 50세에 불과하였으나 후반에 이르러서는 남자 평균 수명 72세, 여자 79세로 늘어나게 되었는데 이것은 공중보건의 기여라고 볼 수 있다. 지난 10년 동안 미국의 보건의료정책은 격변기를 맞았으며 지역사회 병원들은 점차 보건소 활동분야인 예방사업에도 침투하고 있어서 지방보건소 활동과 경쟁하게 되었다. 이로 인하여 지방보건소는 지역사회에서 보다 광범위한 보건증진계획을 세워야 했고 동반자의 참여를 절실해하고 있다. 미국 의학연구소는 "공중보건의 장래" 라는 지침서를 발간하였고 10대 필수보건수칙이 지방보건소를 위하여 정해졌다. 이를 수행하기 위해선 지방보건소가 갖추어야 할 사항은 1) 건강 평가 2) 정책수립 3) 행정력 4) 건강증진 계획 5) 시민건강 보호대책 6) 질적 확인 체재수립 7) 직원교육 훈련 8) 지역사회 자발력 및 참여 고취 등이 있다. 보건교육 사업이란 그 과제와 재능과 개념 등이 다양해 이의 포괄적인 수용이 모색되어야하며, 그래서 이 논문은 건강증진 사업에 대한 "새 눈의 시야"와 같다고 볼 수 있다. "보건교육/보건증진" 이란 공중보건의 이론과 실제를 일체화하는데 있다고 볼 수 있다. 미국은 2010년 보건의료 정책수립에 "건강증진/ 보건교육" 역할을 문서화하였고, "보건교육/ 건강증진" 사업은 지역사회 안에서 체계화하여 "건강한 사회에 건강한 시민" 이라는 사회운동의 청사진으로 이어지고 있다. 이 논문은 콜로라도의 "건강한 사회에 건강한시민" 운동을 한 예로 들고 있으며 "보건교육/건강증진" 사업에 대한 표준 설정을 위하여 노스캐롤라이나주 지방보건소의 "보건교육/건강증진" 표준체제를 예로 들었다. 다음으로, 경제적인 효율면에서 볼 때 "보건교육/건강증진" 사업에는 단기 혹은 장기 투자가치가 있는가 하는 것이다. 새로 태어나는 미국 지방 보건소의 "보건교육/건강증진" 활동은 지역 시민 및 그 단체가 광범위하고도 자연 다발적으로 참여할 때만 성공할 수 있다고 결론 지울 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.43-43
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• 2022

유해 조류 대발생은 전국 각지의 인공호소나 하천에서 다발적으로 발생하며, 경관을 해치고 수질을 오염시키는 등 수자원에 부정적인 영향을 미친다. 본 연구에서는 인공호소에서 발생하는 유해 조류 대발생을 예측하기 위해 심층학습 기법을 이용하여 예측 모델을 개발하고자 하였다. 대상 지점은 대청호의 추동 지점으로 선정하였다. 대청호는 금강유역 중류에 위치한 댐으로, 약 150만명에 달하는 급수 인구수를 유지 중이기에 유해 남조 대발생 관리가 매우 중요한 장소이다. 학습용 데이터 구축은 대청호의 2011년 1월부터 2019년 12월까지 측정된 수질, 기상, 수문 자료를 입력 자료를 이용하였다. 수질 예측 모델의 구조는 다중 레이어 퍼셉트론(Multiple Layer Perceptron; MLP)으로, 입력과 한 개 이상의 은닉층, 그리고 출력층으로 구성된 인공신경망이다. 본 연구에서는 인공신경망의 은닉층 개수(1~3개)와 각각의 레이어에 적용되는 은닉 노드 개수(11~30개), 활성함수 5종(Linear, sigmoid, hyperbolic tangent, Rectified Linear Unit, Exponential Linear Unit)을 각각 하이퍼파라미터로 정하고, 모델의 성능을 최대로 발휘할 수 있는 조건을 찾고자 하였다. 하이퍼파라미터 최적화 도구는 Tensorflow에서 배포하는 Keras Tuner를 사용하였다. 모델은 총 3000 학습 epoch 가 진행되는 동안 최적의 가중치를 계산하도록 설계하였고, 이 결과를 매 반복마다 저장장치에 기록하였다. 모델 성능의 타당성은 예측과 실측 데이터 간의 상관관계를 R2, NSE, RMSE를 통해 산출하여 검증하였다. 모델 최적화 결과, 적합한 하이퍼파라미터는 최적화 횟수 총 300회에서 256 번째 반복 결과인 은닉층 개수 3개, 은닉 노드 수 각각 25개, 22개, 14개가 가장 적합하였고, 이에 따른 활성함수는 ELU, ReLU, Hyperbolic tangent, Linear 순서대로 사용되었다. 최적화된 하이퍼파라미터를 이용하여 모델 학습 및 검증을 수행한 결과, R2는 학습 0.68, 검증 0.61이었고 NSE는 학습 0.85, 검증 0.81, RMSE는 학습 0.82, 검증 0.92로 나타났다.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.522-526
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• 2000

We tried to mass-propagate Prunus yedoensis from Jeju through tissue culture. We investigated the effect of bud collection time, the concentration of $NH_4NO_3$ in media and plant growth regulators(BAP, $GA_3$ and IBA) on the differentiation of winter buds. Buds, taken in February, flushed well regardless of various in vitro conditions. Bud flushing rate was significantly different depending on the collection time. BAP appeared to be effective on bud flushing. Sixty percent of buds taken in October flushed on the media containing $3.0mg/{\ell}$ BAR. No buds flushed on the medium supplemented with IBA. Buds, after flushing in BAP media, grew as foliated shoots and showed a rosette of leaves. When $GA_3$ supplemented to the BAP-containing media as a higher concentration than that of BAP, shoots elongated and developed into normal shoots. The combination of BAP $1.0mg/{\ell}$ and $GA_3$ $2.0mg/{\ell}$ is most recommendable for shoot elongation.

• Radiation Oncology Journal
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• v.26 no.1
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• pp.10-16
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• 2008

Purpose: To compare the treatment outcomes and to analyze prognostic factors between the use of a breast-conserving treatment(BCT) and a mastectomy for early stage breast cancer. Materials and Methods: We retrospectively reviewed 1,200 patients with pathological stage T1-2N0 breast cancer who received surgery between September 1994 and December 2002 at Samsung Medical Center. We compared the patient characteristics and treatment outcomes between the two treatment groups. Results: Among the 1,174 eligible patients, 601(51.2%) patients received a BCT and the remaining 573(48.8%) patients received a mastectomy. The mastectomy group of patients had significantly more cases with a larger tumor size, multicentricity, extensive intraductal component, and estrogen- and progester-one-receptor negativity. The ten-year overall survival rates(OS) of the BCT and mastectomy groups were 91.96% and 91.01%, respectively(p=0.1274). The ten-year disease-free survival rates(DFS) were 80.48% for the BCT group of patients and 84.95% for the mastectomy group of patients, respectively(p=0.8795). Conclusion: Our study shows some differences in patient characteristics between the two treatment groups. However, these differences did not result in significant survival differences.

• Korean journal of applied entomology
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• v.28 no.3
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• pp.167-174
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• 1989

A confined field assessment on the integrated control of vector mosquitoes (Anopheles sinen- sis and Culex tritaent'orhynchus) was conducted by timely treatment of Bacillus thuringiensis(H-14) formulation in the presence of larvivorous fish (Aplocheilus lalipes) in natural rice fields of $30,000M^2$ at Yongam, South Korea Cholla Province from July through October in 1988. In presence of larvivorous fish (Aplocheilus) at lower density of 0.6 fish per $M^2$ water surface, mosquito vector control rates ranged 55. 0~57. 6% from July through August, and when the mosquio density started to increase with over 10 larvae on the average per sample, B.t.(H-14) formulation treatment at the rate of 1. 0 Kg/ha made 100% vectors reduc¬tion in 24 hours, the control sustained above 98% until the test was terminated on October 11th. In the fish introduced rice paddies with Aphyocypris chinensis at the density of above 1. 5 fish per $M^2$, a satisfactory degree of vector control was obtained by 88. 2~96. 7% in 2 week period until September 21st. In the absence of larvivorous fishes, B.t. (H-14) treatment made 100% control in 24 hours, however, vector population rebound appeared in day 7, required to make additional treatment to suppress population down.

• Korean journal of applied entomology
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• v.43 no.1
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• pp.15-20
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• 2004

Leaf damage by apple leafminer, Lyonetia prunifoliella, was surveyed on Fuji apple orchards with seedling rootstock from 1992 to 2001 and with M.9 rootstock from 1999 to 2001. The damage was negligible in apple orchards with seedling rootstock as 0.15% in 1992 and 0.06% in 1993. However it sharply increased to more than 3.39% since 1994, reaching at peak damage of 6.28% to 7.78% in 1996 to 1998. Damages on apple orchards with M.9 rootstock from 1999 to 2001 were higher as 6.09% to 15.3%, compared with those with seedling rootstock in the same years. In seedling rootstock apple, the damage was highest on september but in M.9 rootstock apple, the difference was not significant. Leaf damage showed no differences between cultivars including 4 Korean cultivars and Fuji. These results may explain that increase of M.9 rootstock apple orchards is responsible for the recent outbreak of the leafminer in Korea.

• Journal of Life Science
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• v.13 no.3
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• pp.291-297
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• 2003

A human endogenous retroviral family (HERV-W) has recently been described that is related to multiple sclerosis-associated retrovirus (MSRV) sequences that have been identified in particles recovered from monocyte cultures from patients with multiple sclerosis. Two pol fragments (HWP-FB10 and HWP-FBl2) of HERV-W family were identified and analysed by the PCR approach with cDNA library of human fetal brain. They showed 89 percent nucleotide sequence similarity with that of the HERV-W (accession no. AF009668). Deletion/insertion or point mutation in the coding region of the pol fragments from human fetal brain resulted in amino acid frameshift that induced a mutated protein. Phylogenetic analysis of the HERV-W family from GenBank database indicates that the HWP-FB10 is very closely related to the AC000064 derived from human chromosome 7q21-q22. Further studies on the genetic relationship with neighbouring genes and functional role of these new HERV-W pol sequences are indicated.