• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.77-82
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• 2006

Evaluation of the elliptic blending turbulence model (EBM) together with the two-layer model, shear stress transport (SST) model and elliptic relaxation model (V2-F) is performed for a better prediction of natural convection and thermal stratification. For a natural convection problem the models are applied to the prediction of a natural convection in a rectangular cavity and the computed results are compared with the experimental data. It is shown that the elliptic blending model predicts as good as or better than the existing second moment differential stress and flux model for the mean velocity and turbulent quantities. For thermal stratification problem the models are applied to the thermal stratification in the upper plenum of liquid metal reactor. In this analysis there exist much differences between the turbulence models in predicting the temporal variation of temperature. The V2-F model and EBM better predict the steep gradient of temperature at the interface of thermal stratification, and the V2-F model and EBM predict properly the oscillation of temperature. The two-layer model and SST model fail to predict the temporal oscillation of temperature.

• 대한한의학회지
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• 제32권5호
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• pp.41-49
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• 2011

Objectives: To optimize the preservation method of herbal decoction, we investigated the content of principle components of Pyungwi-san, liquiritin, glycyrrhizin, and hesperidin according to preservation temperature and period. We also investigated the changing patterns of pH and microbial population in Pyungwi-san decoction as a model case. Methods: With samples preserved at different temperatures, the content of liquiritin, glycyrrhizin, and hesperidin was determined using HPLC and microbial population was determined as viable counting method up to 8 times every month. Identification of isolated bacteria was performed by 16S rDNA analysis. Results: The content of liquiritin and glycyrrhizin did not change according to the preservation temperature and period, but that of hesperidin was severely decreased at room temperature. The isolate from the decoction was identified as Bacillus licheniformis by 16S rDNA sequence analysis. Microbial population appeared after 3 months' preservation and reached maximum value at 4 months; at all tested temperatures, the pH showed the lowest value (4.4-4.5) simultaneously. Conclusion: From the results, it seems to be that the microbial growth affects the pH of preserved decoction but not the change of liquiritin and glycyrrhizin content.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.56.1-56.1
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• 2012

The microstructures and mechanical properties of Co-29Cr-6Mo alloy with C and N additions, produced by additive manufacturing using electron beam melting (EBM) method, were studied using X-ray diffraction, electron back scatter diffraction, transmission electron microscope, Vickers hardness tests, and tensile tests, focusing on the influences on the build direction and the various heat treatments after build. It is found that the microstructures for the as built specimens were changed from columnar to equiaxed grain structure with average grain size of approximately $10-20{\mu}m$ due to the heat treatment employing the reverse transformation from a lamellar (hcp + $Cr_2N$) phase to an fcc. Our results will contribute to the development of biomedical Ni-free Co-Cr-Mo-N-C alloys, produced by EBM method, with refined grain size and good mechanical properties, without requiring any hot workings.

• 정보관리학회지
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• 제10권2호
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• pp.3-22
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• 1993

최근 시소러스를 기반으로 하는 불리안 검색 시스템에서 문서의 순위 결정에 사용 될 수 있는 Relevance, R-distance, K-distance와 같은 방법들이 개발되었다. 이러한 방법들은 색인어들 사이의 연관성 정보를 이용하여 문서들의 순위를 결정함으로써 많은 경우에 높은 검색 효율을 제공할 지라도, 불리안 연산자 AND, OR, NOT에 대한 연산 방법이 문제점으로 지적되어왔다. 본 논문에서는 개선된 퍼지 집합 모델과 확장된 불리안 모델을 시소러스가 제공하는 색인어들 사이의 연관성 정보를 효율적으로 이용할 수 있도록 확장함으로써, 기존 방법들의 문제점을 극복하는 새로운 순위 결정 방법 KB-FSM과 KB-EBM을 제안한다. 또한 KB-FSM과 KB-EBM이 Relevance, R-distance, K-distance보다 문서들의 순위를 보다 정확하게 결정함을 성능 비교를 통하여 입증한다.

• 생약학회지
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• 제42권3호
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• pp.240-245
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• 2011

A high-performance liquid chromatography (HPLC) method was developed for quantitative analysis of liquiritin and glycyrrhizin in Sagunja-tang (SGT, Sijunzi-tang in Chinese), a traditional Korean medicine. HPLC analysis was performed using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 254 nm and 280 nm for quantification of the two components in SGT. The mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. Calibration curves were acquired with $r^2$ values > 0.9998, and the relative standard deviations (RSDs, %) for intra- and inter-day precision were not exceed 4.0%. The recovery of each component was in the range of 91.85 - 108.62%, with a RSD less than 4.0%. The contents of the two components in SGT were 7.94 - 13.83 mg/g.

• 대한본초학회지
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• 제26권1호
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• pp.41-46
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• 2011

Objectives : To quantitate the main compounds and investigate the biological activity of Sosiho-tang (Xiao-Chai-Hu-Tang, SST), simultaneous determination of baicalin and glycyrrhizin, and anti-inflammatory activity were estimated. Methods : A quantitative analysis was performed using a high performance liquid chromatography (HPLC). Reference compounds were separated on a reversed-phase column using gradient elution with water and acetonitrile each containing acetic acid at a flow rate of 1 mL/min. And the productions of nitric oxide (NO) and prostaglandin $(PE)E_2$ were examined by lipopolysaccharide (LPS)-treated RAW 264.7 cells in the presence of the SST. The anti-inflammatory activity of SST was investigated by carrageenin-induced paw edema in rats. The paw volume was measured at 2 and 4 hr following carrageenin-induced paw edema in rats. Results : The correlation coefficients of the compounds showed good linearity ($r^2$ > 0.9992) over the linear range. The precisions of intra- and inter-day were less than 7.0% of relative standard deviation (RSD) values for baicalin and less than 3.5% of RDS valuse for glycyrrhizin. Recovery rates were within the range of 95.41-101.5%. The contents of baicalin and glycyrrhizin in SST were average 70.52, 6.18 mg/g, respectively. And SST exhibited inhibitory effect on NO production in LPS-treated RAW 264.7 cells but not on $PGE_2$ production. Oral administration of SST (1 g/kg) showed a reduction in carrageenin-induced paw edema on rats. Conclusions : The analytical method was applied successfully to measure the contents of baicalin and glycyrrhizin in SST which exhibited anti-inflammatory activities.

• 사상체질의학회지
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• 제21권1호
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• pp.237-246
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• 2009

1. Objectives To compare the contents of heavy metals, residual pesticides and sulfur dioxide before/after decoction. 2. Methods The heavy metal contents before/after decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and mercury analyzer. In order to analyze pesticides in 3 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide (SO2) were performed by Monier-Williams distillation method. 3. Results 1) The mean values of heavy metal contents (mg/kg) for the samples were as follows: Yuldahanso-tang (before decoction - Pb; 1.85, Cd; 0.148, As; 0.042 and Hg; 0.003, after decoction - Pb; 0.096, Cd; 0.006, As; 0.006 and Hg; 0.002), Chongsimyonja-tang (before decoction - Pb; 1.193, Cd; 0.094, As; 0.084 and Hg; 0.008, after decoction - Pb; 0.053, Cd; 0.007, As; 0.011 and Hg; not detected) and Taeyeumjowee-tang (before decoction - Pb; 0.878, Cd; 0.078, As; 0.302 and Hg; 0.004, after decoction - Pb; 0.079, Cd; 0.005, As; 0.006 and Hg; not dectcted). 2) Contents (mg/kg) of residual pesticides before/after decoction in all samples were not detected. 3) Contents (mg/kg) of sulfur dioxide (SO2) before decoction in Yuldahanso-tang, Chongsimyonja-tang and Taeyeumjowee-tang exhibited 6.1, 37.8, 31.5 and 19.7, respectively. However, contents of sulfur dioxide after decoction in all samples were not detected. 4. Conclusion These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• 한국제4기학회지
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• 제24권2호
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• pp.1-11
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• 2010

지표 특성 차이에 따라 외부강제력에 대한 차별적인 반응을 보이는 지표 평형온도 분포를 실험하기 위해 에너지 균형 모형(Energy Balance Model, EBM)이 사용되었다. EBM은 입사되는 복사에너지가 각 위도별로 수송되는 에너지와 방출되는 복사에너지의 합과 균형을 이루었을 때의 온도를 산출한다. 지구의 에너지 원천인 태양복사에너지를 전지구 에너지 균형에 있어 중요하게 취급하기 위하여 위도별 알베도 변화뿐만 아니라 해륙의 분포 차이에 따른 에너지 균형을 고려한 지구 평형온도 분포에 관한 실험이 수행되었으며, 입사되는 태양복사에너지량을 강제력으로 하여 위도별 알베도의 선형적인 증감, 극지역 알베도의 5%, 10%, 15% 증감에 대한 반응, 극과 중위도 지역에서의 상반된 증감에 대한 반응을 실험하였다. 그리고 얼음-알베도 피드백의 유무에 대한 실험도 수행되었다. 극지역의 알베도를 증가시키면 입사되는 태양에너지를 차단시켜 위도별 열수송을 감소시키는데 이는 극지역을 저에너지 상태로 유지시킴으로써 저위도에서부터의 에너지 수송을 강화시킨다. 이러한 수송량의 차이로 인해 중위도 지역의 온도 변화는 극지역에 비해 크게 나타난다. 육지는 해양에 비해 열용량이 작기 때문에 평형온도에 도달하는 시간이 짧으며 알베도에 따른 온도변화에 민감하여 해양과의 온도차이를 유발시킨다. 따라서 평형온도는 지표가 가지는 특성인 알베도와 열용량의 차이에 따라 다르게 나타나며 알베도가 증가함에 따라 감소하고 열용량이 작을수록 변화율이 큰 특징이 있다. 얼음-알베도 피드백은 알베도의 선형적인 증가에 따른 지구 평형온도의 감소를 가속화시키지만 국지적으로는 비선형적인 감소를 보인다.

• 대한예방한의학회지
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• 제16권3호
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• pp.89-105
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• 2012

Objectives : This study was carried out to know the status of clinical utilization of Korean medical knowledge and the Korean medical knowledge system which Korean medical doctors want. Methods : Questionnaires were distributed to Korean medical doctors registered for the Association of Korean medicine via the email and 249 answered questionnaires were analyzed. Results : 50.6 % of Korean medical doctors utilized the textbooks for Korean medicine when they treated their patients. The reason why they did not utilize the textbooks for Korean medicine was mostly that 'it could not be applied directly into clinical application with only contents of textbook because clinical approach (diagnosis and treatment methods) was not clearly described in the textbook'. 48.6 % of Korean medical doctors utilized the EBM materials when they treated their patients. EBM materials that they referred included domestic articles, other EBM materials excluding papers and international academic papers based on PubMed in order. The reasons why they did not utilize the EBM materials were mostly that 'it was difficult to find the evidence' and 'EBM materials were not actually helpful for the clinical practice.' It was found that Korean medical doctors approached the disease in aspects of Korean and Western Medicine concurrently upon the diagnosis of patients and performed the diagnosis and treatment of Korean medicine on the diseases which seemed to be effective with Korean medicine. It was also found that they thought that they needed to know the Western medical knowledge as much as general doctors who have a doctor's license or family medicine specialists who comprehensively treat the general diseases know. Korean medical doctors wanted to have the systematic summary of modern research performance in fields of acupoint, acupuncture, herbal drugs and formula. They thought that constitutional medicine and Sa-am acupuncture therapy were representative characteristics in Korean medicine differentiated from Traditional Chinese medicine and Kampo medicine. Conclusions : Korean medical doctors wanted to establish the Korean medical knowledge system based on evidence focusing on clinical and practical contents. New Korean medical knowledge system should be established based on these requirements in the future.

• 한국응용곤충학회지
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• 제60권2호
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• pp.255-262
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• 2021

감자뿔나방은 감자에 대한 검역 해충으로 알려져 있다. 본 연구는 전자빔 조사가 감자뿔나방의 발육 및 생식, 그리고 DNA 손상에 미치는 영향을 비교하고 억제선량을 조사하였다. 전자빔을 알(0-12시간 이내), 유충(3령과 5령), 번데기(용화 1일 이내), 그리고 성충(우화 1일 이내)에 선량을 증가시키면서 조사하였다. 전자빔 150 Gy는 알의 부화와 부화된 유충의 용화를 완전히 억제하였다. 조사된 알의 부화율은 19.3%였지만, 성충 우화는 완전히 억제되었다. 3령과 5령 유충에 100 Gy를 조사하였을 때, 성충의 우화와 생식은 완전히 억제되었다. 번데기와 성충에 각각 300 Gy와 400 Gy를 조사하였을 때, F₁세대의 부화율이 억제되었다. 전자빔에 대한 감자뿔나방 성충의 DNA 손상 정도를 alkaline comet assay으로 분석하였으며, 전자빔 조사가 선량 의존적으로 감자뿔나방의 DNA 손상 정도를 증가시켰다. 이러한 결과는 감자뿔나방에 대한 식물 검역 처리법으로 전자빔 150 Gy를 권장할 수 있다. 하지만, 감자뿔나방을 방제하기 위해 전자빔을 현장에 적용하기 위해서는 추가적인 연구가 필요할 것으로 사료된다.