• Bulletin of the Korean Chemical Society
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• 제11권1호
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• pp.49-54
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• 1990

The gas-phase thermolysis reactions of ${\alpha}$- and ${\beta}$-methylated ethyl formates, Y = $CH-X-CHR_1CH_2R_2$ where X = Y = O or S and $R_1\;=\;R_2$ = H or $CH_3$, are investigated theoretically using the AM1 method. The experimental reactivity order is reproduced correctly by AM1 in all cases. The thermolysis proceeds through a six-membered cyclic transition state conforming to a retro-ene reaction, which can be conveniently interpreted using the frontier orbital theory of three-species interactions. The methyl group substituted at $C_{\alpha}\;or\;C_{\beta}$ is shown to elevate the ${\pi}$-HOMO of the donor fragment (Y = C) and depress the ${\sigma}^{\ast}$-LUMO of the acceptor fragment ($C_{\beta}$-H), increasing the nucleophilicity of Y toward ${\beta}$-hydrogen which in turn increases the reactivity. The two bond breaking processes of the $C_{\alpha}$-X and $C_{\beta}$-H bonds are concerted but not synchronous so that the reaction takes place in two stages as Taylor suggested. The initial cleavage of $C_{\alpha}$-X is of little importance but the subsequent scission of $C_{\beta}$-H occurs in a rate determining stage.

• 한국한의학연구원논문집
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• 제8권2호통권9호
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• pp.75-84
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• 2002

Obesity can be defined as a metabolic disease due to a increased state of fat tissue caused by an imbalance of calorie intake and use. To define genes that affected by different nutrient, we study gene expression from mice which were fed different nutrient. Epididymal and retro-peritineal adipose tissue were increase in high fat diet feeding mice compared with control, but liver and spleen were not. In serum, total cholesterol were differently increase in high fat diet feeding mice but total triglyceride and free fatty acid were not. That was maybe result of energy balance regulation in vivo system. aP2, PPART2 and FAS genes that were increased during adipogenesis were inclosed in high fat diet fed mice compared with control. In microarray assay, 1.4% of total genes were affected in epididymal adipose tissue by different nutrient. 1.1% of total genes were decreased down 0.5 fold and 0.3% were increased over 2 fold. These results indicated that many genes are affected in adipose tissue by nutrient.

• 패션비즈니스
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• 제5권2호
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• pp.73-86
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• 2001

This study aims at reviewing the Kitsch aesthetics, grasping the relation between the Kitsch and consumption culture, and pursuing the intrincis meanings and expressive characteristics of Kitsch in the hair style and head dress in the 1990s. Kitsch generally implies a vulgarity, and a bad taste, and can be considered to be a kind of vicarious experience, the aesthetic deception and self-deception. In spite of these negative inplications of Kitsch, the aesthetic categories of Kitsch have been spread to public and been accepted by the public, with the help of the powerful promotion of the modern day mass media. 1. The intrincis meanings of Kitsch convey 1) escapism, 2) conformity, 3) amusements, 4) identification. 2. The expressive characteristics of Kitsch represent 1) aesthetic inadequacy: hair style and head dress showing the imperpectness, accumulation(superfluous ornaments), vulgarity, untidines. 2) resistance: hair style and head dress featuring deconstructional and violent forms revealing the uneasiness, and unsatisfaction of the given regularity. 3) humor: hair style and head dress featuring the innocence, humor, and fun for a relaxation and diversion. 4) hedonism: hair style and head dress with the erotic and sexual feelings. 5) retro, romantism: hair style and head dress featuring the elegance, femininity, folklore, ethnic, and nostalgia.

• Journal of Gastric Cancer
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• 제13권3호
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• pp.185-187
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• 2013

Neurofibromas are benign tumors that originate from the peripheral nerves, including neurites and fibroblasts. Generally, a solitary neurofibroma is located in the skin and rarely in other places. A 72-year-old female suffered from epigastric discomfort for 2 months. Endoscopic findings showed an early gastric cancer type IIc at the antrum. Abdominal computed tomography revealed early gastric cancer with a 1.6 cm-sized metastatic node posterior to the duodenum. Laparoscopic assisted distal gastrectomy and retro-pancreatic dissection were performed uneventfully. Histological examination revealed gastric adenocarcinoma, invading the mucosa without nodal metastasis, and a neurofibroma. Herein, we present a case of a gastric cancer patient with a solitary retroperitoneal neurofibroma which mimicked a distant metastatic node.

• 한국전자파학회논문지
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• 제26권1호
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• pp.113-118
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• 2015

본 논문에서는 병렬 믹서 구조의 역지향 배열 안테나 시스템을 제안하고, 이를 능동 상쇄에 적용하였다. 주파수 체배기를 이용해 입사 신호의 두 배 주파수를 발생시켜 국부 발진 신호로 활용함으로써 임의의 주파수에서 위상 공액 특성을 자동적으로 얻을 수 있다. 이러한 특성의 제안된 시스템은 전자기파가 입사할 경우 입사 방향뿐만 아니라 주파수에 대한 사전 지식이 없더라도 입사 방향으로 상쇄 신호를 송신할 수 있으므로 능동 상쇄를 위해 활용될 수 있다. 또한, 병렬믹서 구조를 통해서 주파수가 동일한 믹서의 입출력 신호 사이의 높은 격리도를 확보함으로써 정확한 입사 신호 방향으로 송신 신호를 발생 시킬 수 있다. 실험적 검증을 위해서 병렬 믹서 방식의 $2{\times}2$ 역지향 배열 안테나 시스템을 설계, 제작하여 금속성 원통에 대한 반사파 상쇄 실험을 수행하였다. 제안된 시스템 적용 후 반사 신호의 크기가 최대 26 dB까지 감소되는 결과를 통해 제안된 방법의 유효성을 확인하였다.

• 대한소아치과학회지
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• 제46권1호
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• pp.85-92
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• 2019

이 연구의 목적은 유치 줄기세포에 대해 다양한 Calcium silicate-based material (CSM)의 세포독성을 비교하고 평가하는 것이다. Retro $MTA^{(R)}$ (RM), $EZ-Seal^{TM}$ (EZ), ENDOCEM $Zr^{(R)}$ (EN)의 powder를 세포 배지를 이용하여 용출시키고 filtering 하였다. 유치 줄기세포가 다양한 농도의 용출액 하 배양되었다. MTS assay를 통해 CSM 용출액이 세포 증식에 미치는 영향을 분석하였고, Flow cytometry analysis를 통해 세포 표현형의 변화 여부를 관찰하였다. 10% 농도의 용출액에서 배양된 유치 줄기세포의 흡광도 값은 RM > EN > EZ 순이었다(p = 0.0439). 그러나 유치 줄기세포는 재료에 관계없이 간엽줄기세포의 표현형을 유지했다. 세 종류의 CSM이 줄기세포 marker를 변형시키진 않았지만, EZ가 RM과 EN보다 세포적합성이 낮음을 알 수 있었다.

• 한국생활과학회지
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• 제13권1호
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• pp.159-171
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• 2004

The purpose of this study was to compare the characteristic of Chanel style between modern and postmodern period. The documentary research method was used for this study. The modem period was limited from around 1920 through 1939 and the postmodern period from 1990 through present for this research. The results were summarized as follows: The characteristics of clothing style in modem period were 1) the preference of slim & straight body figure as ideal one and slim & straight clothing silhouette, 2) the high fashion image for the elite by simple & basic design, 3) the emphasis on the harmony by the unity, 4) the tendency of eliminating ornaments on clothing, 5) the discontinuation of traditional way of dress code & style, and 6) the modern style. The characteristics of clothing style in postmodern period were 1) the emphasis on erotic aspects of female body and sexy design, 2) the popularization of high fashion and certain social group's fashion, 3) the tendency of harmony by mix-match, 4) the preference of ornaments in clothing, 5) the preference of retro-fashion, and 6) the continuation of modem style.

• 대한수의학회지
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• 제47권2호
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• pp.247-254
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• 2007

This study was performed to identify the normal anatomic orientation of pulmonary arteries and to obtain the normal baseline parameters and the optimal contrast material delivery methods of computed tomographic pulmonary angiography (CTPA) on normal beagle dogs. Based on the contrast injection flow rate, the contrast volume, and the administration methods, the experimental groups were divided into 4 groups such as group 1 : 2 ml/s, 3 ml/kg, and monophasic administration; group 2 : 5 ml/s, 3 ml/kg, and monophasic administration; group 3 : 5 ml/s, 4 ml/kg, and monophasic administration; group 4 : 5 ml/s and 2 ml/kg in first phase, 0.3 ml/s and 2 ml/kg in second phase, as biphasic administration. Normal anatomic orientation of pulmonary arteries in CTPA was evaluated through reformatted and 3D images after retro-reconstruction. Normal parameters for great arteries and peripheral pulmonary arteries were obtained on the factor of basement hounsfield unit (HU) values, contrast enhanced HU values, delay time, and peak time. And the optimal contrast delivery methods were evaluated on the factor of contrast enhanced HU values, image quality, and artifact. The monophasic administration with 5 ml/s contrast injection flow rate and 3 ml/kg contrast volume was optimal in canine CTPA.

• 한국의상디자인학회지
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• 제9권2호
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• pp.139-154
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• 2007

Wellbeing means the new life style leading a rich and nice life in which body and spirit is combined organically, and influence of wellbeing culture extends throughout the society. The purpose of this study is to analyze the aesthetic characteristics of Korean wellbeing fashion. Fashion photographs from leading monthly fashion magazines from 2001 to 2005 were analyzed. The styles and materials and colors were examined from 1,151 wellbeing fashion designs that is based on wellbeing culture. The major conclusions of the study are as follows : 1. The styles of wellbeing fashion in Korea include sportive, ecology, ethnic, retro styles in order. 2. Wellbeing fashion in Korea increased double in 2005 compared to 2001. Not least, sportive style and ethnic style rapidly increased. 3. Materials of wellbeing fashion in Korea include cottons, wools, chemical fibers, silks, jutes, functional fibers in order. Particularly the use of cottons in 2005 increased three times compared to 2001. 4. Of wellbeing fashion colors, yellow in bright tone were present the most, followed by white, red, black, green, blue, grey in order. Natural colors, vivid colors, pastel tone colors were used.

• Advances in aircraft and spacecraft science
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• 제8권1호
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• pp.53-67
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• 2021

The increasing interest in the exploration of Mars stimulated the authors to study aerodynamic problems linked to space vehicles. The aim of this paper is to evaluate the aerodynamic effects of a flapped wing in collaborating with parachutes and retro-rockets to reduce velocity and with thrusters to control the spacecraft attitude. 3-D computations on a preliminary configuration of a blunt-cylinder, provided with flapped fins, quantified the beneficial influence of the fins. The present paper is focused on Aerodynamics of a wing section (NACA-0010) provided with a trailing edge flap. The influence of the flap deflection was evaluated by the increments of aerodynamic force and leading edge pitching moment coefficients with respect to the coefficients in clean configuration. The study was carried out by means of two Direct Simulation Monte Carlo (DSMC) codes (DS2V/3V solving 2-D/3-D flow fields, respectively). A DSMC code is indispensable to simulate complex flow fields on a wing generated by Shock Wave-Shock Wave Interaction (SWSWI) due to the flap deflection. The flap angle has to be a compromise between the aerodynamic effectiveness and the increases of aerodynamic load and heat flux on the wing section lower surface.