• 대한기계학회논문집A
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• 제24권3호
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• pp.645-652
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• 2000

A method for shape design sensitivity analysis is proposed utilizing commercial software ANSYS for thermal conduction problems. While the sensitivity formula is derived analytically by introduing adjoint variable concept, sensitivity calculation in practice as well as the primal and adjoint solution of thermal conduction is performed using the ANSYS very easily. Since the formula always takes boundary integral form, sensitivity evaluation in ANSYS requires a little more addition of post-processing routine which involves evaluation of boundary variable from the obtained solution. Though the BEM has been used as a better tool for this purpose, the present study shows it can also be calculated using any kind of analysis code such as ANSYS since the formula is based on analytic nature. Therefore the present study provides a new and efficient way of optimization which was not possible before using commercial software. The usefulness of the method is illustrated via a weight minimization problem of thermal diffuser.

• The Journal of Korean Physical Therapy
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• 제19권1호
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• pp.23-31
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• 2007

Purpose: As a preliminary study, the purpose of this study was to examine the indirect estimation of the lumbar intervertebral disc size by two anthropometric methods, in order to compare these indirect methods with the direct analysis by radiological imaging. Methods: The wrist, elbow, knee, and ankle joint (both right and left) diameters were measured in 52 volunteers, and then intervertebral disc size was calculated using two anthropometric methods (Colombini and modified Colombini). The data were analysed with independent t-test to assess clinical usefulness. Results: When using right and left joint diameter, there was no significant difference in the estimation value of the L4-5 and L5-S1 intervetebral disc sizes. However, the study has shown that male subjects have significantly larger L4-5 and L5-S1 intervertebral disc sizes, compared with those of female subjects. In addition, disc sizes calculated by Colombini's formula were significantly larger than modified Colombini's formula. Conclusion: The indirect estimation of the intervertebral disc size by anthropometric method can be considered as a clinically useful method. However, further study should be conducted to compare anthropometric values with other radiological imaging.

• Food Science and Biotechnology
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• 제16권4호
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• pp.590-593
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• 2007

The textural properties of doughs mixed with L-ascorbic acid (AA), trypsin hydrolyzed gluten peptide (THGP), and a mixture of AA-THGP were investigated using texture analyzer under the fermentation of the full formula and the freezing process. The full formula dough (FFD) required a shorter mixing time than the flour and water formula dough (FWD). The maximum resistance (Rmax) values of both the unfrozen and frozen doughs were lower for the FFD. The effects of AA and THGP additions were not significant (p<0.01) in FFD, however, they were significant in FWD. The freezing effect was significant (p<0.0001) for FFD, indicating that yeast fermented dough was much more sensitive to damage from freezing, which subsequently affected dough strength. Additions of AA (p=0.0026) and THGP (p=0.0097) had a significant effect on the extensibility (E-value) of unfrozen FWD, where THGP increased and AA decreased the E-value. However, freezing did not significantly effect the extensibilities of FWD (p=0.64) or FFD (p=0.21). The area of FFD was lower than the area of FWD for both the unfrozen and frozen doughs. However, the frozen dough mixed with THGP alone had the largest area overall. The addition of additives did not result in significantly different (p<0.01) areas under the curve, except in the frozen FFD. Freezing caused a statistically significant difference in the area of FWD (p=0.0045).

• Toxicological Research
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• 제25권4호
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• pp.225-230
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• 2009

The genotoxic effects of DHU001, a polyherbal formula were evaluated using the mouse micronucleus test. DHU001 was administered once a day for 2 continuous days by oral gavage to male ICR mice at doses of 2000, 1000 and 500 mg/kg. Cyclophosphamide was used as a known genotoxic agent in a positive control. The appearance of a micronucleus is used as an index for genotoxic potential. In addition, the changes on the total white blood cells and differential counts on the lymphocytes, neutrophils, eosinophils, basophils and monocytes in the prepared blood smears were also conducted to observe the possible immunosuppression. The results indicats that DHU001 showed no genotoxicity effects up to 2000 mg/kg dosing levels and did not influenced on the total white blood cells and differential counts. In addition, it is also considered that there were no problems from cytotoxicity of DHU001 tested in this study because the polychromatic erythrocyte ratio was detected as > 0.41 in all tested groups.

• Toxicological Research
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• 제24권3호
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• pp.213-218
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• 2008

In this research, the genotoxic effects of Kong-Jin-Dan(KJD), a polyherbal formula were evaluated using the mouse micronucleus test. KJD was administered once a day for 2 continuous days by oral gavage to male ICR mice at doses of 2000, 1000 and 500 mg/kg. Cyclophosphamide was used as a known genotoxic agent in a positive control. The appearance of a micronucleus is used as an index for genotoxic potential. In addition, the changes on the total white blood cells and differential counts on the lymphocytes, neutrophils, eosinophils, basophils and monocytes in the prepared blood smears were also conducted to observe the possible immunosuppress. The results obtained indicated that KJD shows no genotoxicity effects up to 2000 mg/kg dosing levels, but KJD shows slight increased trends in the blood total leukocyte numbers as pharmacological effects of immune stimulation. In addition, it is also considered that there were no problems from cytotoxicity of KJD tested in this study because the polychromatic erythrocyte ratio was detected as > 0.42 in all tested groups.

• 대한한의학방제학회지
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• 제19권2호
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• pp.93-108
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• 2011

Objectives : Angelica sinensis has been used extensively in Korean traditional medicine. Although thorough clinical trials are lacking, Various pharmacological actions for Angelica sinensis has been identified newly using animal models. In addition, it was reported that reactive intermediates, potentially causing toxic effects, was isolated from components in Angelica sinensis. In this article, it was purposed for explanation and introduction of new studies for Angelica sinensis. in terms of Pharmacological action and Toxicity. Methods : New studies for Angelica sinensis were reviewed and summarized in terms of pharmacological action and toxicity. Results and Conclusions : Angelica sinensis and its components including phthalide, phthalide dimers, polysaccharides, polyacetylenes, ligustilide와 butylidenephthalide as well as organic acid showed a variety of pharmacological actions on uterine, cardiovascular system and immune system. In addition, it was identified that three components of such as ligustilide, caffeic acid and safrole was biotransformed to reactive intermediates causing possibly toxicity.

• 대한한의학방제학회지
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• 제19권1호
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• pp.219-231
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• 2011

Objectives : This study was designed to determine the effects of the GGEx18 ethyl acetate fraction(EF) on body weight gain, feeding efficiency ratio, and obesity-related factors in plasma as well as histology of liver and adipose tissues using high fat diet-fed male C57BL/6N obese mice. Methods : 8 weeks old, high fat diet-fed obese male mice were divided into 5 groups: C57BL/6N normal, control, EF(1), EF(2) and EF(3). After mice were treated with EF for 9 weeks, we measured body weight gain, food intake, feeding efficiency ratio, fat weight, plasma leptin and lipid levels. We also analysed histology of liver and adipose tissues on high fat diet-fed male C57BL/6N obese mice. Results : Compared with control, EF-treated mice had significantly lower body weight gain and feeding efficiency ratio. Consistent with the effects on body weight gain, EF significantly decreased the adipose tissue weight compared with control. Consistent with the effects on feeding efficiency ratio, EF significantly decreased plasma leptin concentrations compared with control. EF reduced the size of adipocytes as well as hepatic lipid accumulation compared with control. EF seems to be safe since not only the plasma levels of ALT and AST are within the normal range, but also EF did not show any toxic effects on organs. EF(3) was most effective among EF(1), EF(2), and EF(3) at doses of 25, 50, and 100 mg/kg, respectively. Conclusions : These results demonstrate that EF effectively reduces body weight gain, feeding efficiency ratio in high fat diet-fed obese mice, leading to the modulation of obesity. In addition, EF decreases the size of adipocytes and improves plasma lipids and controls hepatic lipid accumulation, suggesting that EF may act as a therapeutic agent for obesity.

• 지적과 국토정보
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• 제52권1호
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• pp.5-16
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• 2022

다각형 필지의 면적오차계산에 대한 일반식으로부터 직사각형 필지의 면적오차계산식을 도출하고 관련 법률 시행령에서 정하고 있는 면적오차계산의 상수항 0.026² × M(축척분모)이 갖는 의미를 분석하였다. 그 결과, 현행의 면적오차 공식은 직사각형 필지모형으로서 도해측량의 특성을 적절히 반영하고 있으나, 정량적으로는 면적오차를 비교적 크게 허용한다는 것을 알 수 있었다. 또, 면적이 같더라도 필지의 형상에 따라 정사각형 필지보다 50% 더 많은 면적오차가 산출될 수 있다는 문제, 필지 분할시 허용면적오차가 달라져야 하는 문제 등을 파악하였다. 이와 더불어, 본 연구에서 도출한 면적오차계산식으로써 지적측량의 관점에서 문제를 한꺼번에 해결할 수 있는 방안을 제시하였다. 즉, 필지의 크기와 형상을 반영하는 문제, 측량의 정확도를 반영하는 문제, 도해측량과 수치측량을 구분할 필요 없이 단일의 면적오차계산식을 채택하는 문제에 대한 해결책이다. 이들 문제를 해소하는 새로운 면적오차계산식의 채용은 많은 관련 요소들의 개선을 촉진하여 선진적 지적제도로의 발전을 강화할 것이다.

• 한국지반신소재학회논문집
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• 제22권2호
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• pp.71-83
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• 2023

해안구조물의 기능 유지를 위해서 침하량을 예측하는 것은 매우 중요하다. 이를 위한 방법으로는 유한요소해석법이나 실물 및 모형실험 등을 들 수 있지만, 이는 비용과 시간이 많이 소요된다는 단점을 가지고 있다. 따라서 본 연구는 케이슨식 안벽구조물의 침하량을 간편하게 예측할 수 있는 간편식 제안을 목적으로 연구가 진행되었다. 연구 진행 과정은 속도의 PSI(Power Spectrum Intensity)를 산정 후, 기존 중력식 방파제의 간편식에 대입하여 구조물의 침하량을 구한다. 이를 수치해석을 통해 얻은 구조물의 침하량과 비교 분석하여 기존 간편식 침하량과 수치해석 침하량 간의 오차가 다소 큰 것을 확인하였고, 이는 기존 간편식의 경우 배후지반에 대해 고려할 수 없었기 때문임을 확인하였다. 따라서 본 연구는 안벽구조물의 배후지반에 대한 보정계수를 제안함으로써 케이슨식 안벽구조물의 침하량을 구할 수 있는 간편식을 나타내었다. 수치해석 침하량과 비교하였을 때, 이 간편식은 케이슨식 안벽 침하량을 산정하는데에 충분한 정밀도를 가지고 있다고 판단하였다. 또한 시간과 비용이 부족한 상황에서 내진성에 취약한 시설을 간편하게 추출할 수 있으며, 스크리닝 기법으로 활용될 수 있을 것으로 기대된다.

• 한국소음진동공학회논문집
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• 제22권1호
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• pp.29-37
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• 2012

This paper is concerned with the natural vibration characteristics of a rectangular plate with a rectangular hole in contact with the water. The addressed problem was solved by using the Rayleigh-Ritz method combined with the Green function method. This study presents the numerical approach, numerical results and experimental results. In addition, the validity of the approximate formula which mainly depends on the so-called non-dimensionalized added virtual mass incremental factor and the natural mode shape change due to the presence of the water were investigated. Experiments were also carried out to validate theoretical results. The theoretical results are in good agreement with the experimental results. It was found that the effect of a square hole on the natural frequencies of the square plate in contact with water is different from the effect of a square hole on the natural frequencies of the square plate in air and the approximate formula can predict lower natural frequencies in water with a good accuracy.