• 한국응용과학기술학회지
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• 제40권6호
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• pp.1330-1339
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• 2023

약용식물 황련(Coptis Japonica)을 이용한 세럼이 피부 항노화에 효과적인지 검증하기 위해 피험자의 피부 탄력과 윤기를 측정하여 개선율을 분석하고 설문을 통해 만족도를 평가하였다. 22명의 여성 피험자 한쪽 뺨 부위에 황련 추출물을 3% 배합한 세럼을 4주 동안 사용하게 한 후 시험 부위를 측정한 결과 피부 탄력은 사용 전 0.8505 ± 0.0395 R2(mm)에서 4주 후 0.8993 ± 0.0234 R2(mm)로 5.73% 증가하였다. 피부 윤기는 55.94 ± 5.49 (a.u.)에서 58.59 ± 4.66 (a.u.)로 4.74% 증가하였으며 유의확률이 모두 p<0.001로 나타나 두 항목 모두 개선율이 유의하게 증가한 것으로 나타났다. 설문에 의한 탄력 개선은 피험자 모두 100% 만족하는 것으로 나타났고 윤기 개선은 95.5% 만족하는 것으로 나타났으며 시험 기간 내 피부 이상은 확인되지 않았다. 이와 같은 결과는 향후 황련 추출물을 이용한 항노화 기능성 화장품의 연구와 제품 개발에 본 연구가 기초 자료로 활용될 것으로 사료된다.

• 한국산업융합학회 논문집
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• 제17권1호
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• pp.7-14
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• 2014

In this study, characteristic of elastic paving materials in bicycle road using polyurethane were studied experimentally. As a results, following their good result was obtained. Bicycle road packaging materials are flexural strength g test, ratio of mass change after freezing and thawing, repulsion elasticity test, water Permeation coefficient test and slip resistance test results showed good performance.

• 한국식품과학회지
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• 제16권2호
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• pp.175-178
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• 1984

냉면 국수를 제조함에 있어 전분과 밀가루의 혼합비와 식염 및 알카리 첨가제의 첨가량에 따른 국수발의 기계적 성질의 변화를 creep test로 측정하였다. Creep test의 초기 변형율을 정확히 측정하기 위하여 VTR시스템으로 사진을 찍어 분석하였다. 국수발의 creep 커브는 Burgers의 4-element모델로 분석될 수 있었다. 반죽에 전분의 비율의 높아질수록 삶은 국수발의 순간 탄성치와 뉴우턴 점성치는 감소 하였다. 90% 전분을 포함한 반죽에 식염을 가할 경우 식염농도 4 % 수준까지는 순간탄성이 감소하였다. 알카리 첨가제 첨가시 국수발의 순간탄성, 지연탄성, 지연시간 및 뉴우턴 점성치들이 불규칙하게 변하였으며 그 효과를 일관성 있게 나타낼 수 없었다.

• 한국강구조학회 논문집
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• 제12권6호
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• pp.759-767
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• 2000

본 연구는 화재발생후에 시간경과에 따른 콘크리트충전 강관기둥의 내력변화를 파악하고 인장강도시험을 통해 내화실험이전과 후의 항복강도, 인장강도, 평균연신율 및 탄성계수 등에 대하여 각 단계별 하중에 따른 변형률을 비교측정하였다. 화재를 입은 강관내의 충전콘크리트의 물성변화(압축강도 및 탄성계수시험)를 파악하기 위하여 화재실험후 강관중심부에서 코아시험체를 채취하여 압축강도를 측정하고 탄성계수의 측정은 응력에 의한 변형률을 측정하였으며, 대상실험체의 화재온도를 추정하기 위하여 시차열분석을 실시하였다. 이러한 실험결과로부터 얻어진 자료를 평가하여, 향후 콘크리트 충전강관의 내화설계 구조규준제정에 필요한 기초자료를 제시하는데 그 목적이 있다.

• Structural Engineering and Mechanics
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• 제51권6호
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• pp.923-937
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• 2014

The rational finite element method is different from the standard finite element method, which is constructed using basic solutions of the governing differential equations as interpolation functions in the elements. Therefore, it is superior to the isoparametric approach because of its obvious physical meaning and accuracy; it has successfully been applied to the isotropic elasticity problem. In this paper, the formulation of rational finite elements for plane orthotropic elasticity problems is deduced. This method is formulated directly in the physical domain with full consideration of the requirements of the patch test. Based on the number of element nodes and the interpolation functions, different approaches are applied with complete polynomial interpolation functions. Then, two special stiffness matrixes of elements with four and five nodes are deduced as a representative application. In addition, some typical numerical examples are considered to evaluate the performance of the elements. The numerical results demonstrate that the present method has a high level of accuracy and is an effective technique for solving plane orthotropic elasticity problems.

• International Journal of Human Ecology
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• 제8권1호
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• pp.27-37
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• 2007

The purpose of this study is to investigate the preference of the hand and the sensibility image of underwear textiles according to seasons. According to a recent survey of 109 college students, using a 7 scale evaluation to the preference of the hand and the sensibility image among 13 summer and 10 winter underwear textiles. The data was analyzed through mean, SD, factor analysis, t-test, Person correlation analysis and regression analysis using SPSS Win 11.0. The summer underwear textiles were classified according to six tactile factors: stiffness/surface unevenness, weight, elasticity, moistness, extension, and warm-cool and 3 sensibility image factors: elegant individual, modern, and sporty-casual. The winter textiles were classified according to six tactile factors: stiffness/surface unevenness, elasticity, warm-cool, drapability, moistness and flexibility and divided into 2 sensibility images: modern elegant and sporty-casual. Factors expressing hand and sensibility image according to season showed significant difference. In the summer, weight, in the winter, drapability and flexibility showed significant difference at the hand factor evaluation. The hand factors: weight, warm-cool and modern sensibility image factors effect the preference of summer underwear textile, also the hand factors-elasticity, stiffness/surface unevenness and the sensibility image factor-easy-sport-casual-effect the preference of winter textiles. Therefore, the thin, light, and cool textiles which are also gorgeous and sporty-casual are preferred for summer underwear textiles while soft, simple and comfortable textiles are preferred for winter textiles.

• 대한치과기공학회지
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• 제36권3호
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• pp.165-169
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• 2014

Purpose: This study is a mechanical strength supplementation of denture base resin Polymethyl methacrylate (PMMA) is in general use for denture base resin of the partial and full denture, however, The polymerization process of PMMA is not stabilized. Because of compatibility problems, preceding studies were performed, which were enhancing mechanical strength(Camilo Machado 2007),(Ana M. 2008), addition filler to materials property(Ayse Mese, 2008), self curing method(Hiroshi Shimizu, 2008). Methods: The carbon fiber and polyacetal filler, reinforced the mechanical strength for improving the stability of denture base resin were supplemented to the self cured resin. The Modulus of elasticity and the restoring force were calculated by tensile test. Results: The strengths of the heat and self cured resin were respectively decreased and increased, when the filler was supplemented to the denture base resin and the modulus of elasticity of both heat and self cured resin were not increased, when the filler was supplemented to the denture base resin. Conclusion: The restoring forces of self cured resin containing 10% filler were increased, when the filler was supplemented to the denture base resin.

• 한국축산식품학회지
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• 제36권2호
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• pp.237-243
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• 2016

Many researchers revealed that collagen contribute to maintaining the skin’s elasticity and inhibit wrinkling of skin. Korean native cattle (Hanwoo) bone (leg bone, foot and tail) infusion contains the various inorganic materials, collagen and chondroitin sulfate. All of this, a large quantity of collagen is included in Hanwoo infusion. Therefore, this study emphasized on the effects of collagen in the Hanwoo bone infusion. For the first time, Hanwoo bone infusions were directly added to the media of Human Dermal Fibroblast (NHDF-c) to test anti-aging effects. First, it was identified that growth rate of skin fibroblast was increased. Furthermore, the Hanwoo bone infusion increased a 50% of fibroblast collagen synthesis. Also, suppression of skin fibroblast aging was confirmed by treatment Hanwoo bone infusion. In conclusion, this study demonstrates the effects of infusion made from Hanwoo leg bone, foot and tail on anti-aging, wrinkle inhibiting and skin fibroblast elasticity maintaining. Therefore, this study identified that traditional infusion has effects that are good for skin elasticity.

• Advances in concrete construction
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• 제10권6호
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• pp.489-498
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• 2020

This paper investigates mechanical properties of roller compacted concrete (RCC) involving reclaimed asphalt pavement (RAP). In this way, a set of 276 cylindrical RCC specimens were prepared with different RAP sizes (i.e., fine, coarse & total) at various ratios (i.e., 10%, 20%, and 40%). Results reveal that incorporation of RAP decreases unconfined compressive strength (UCS), modulus of elasticity (E), and indirect tensile (IDT) strength of RCC. For each RAP size, a regression model was used to maximize RAP content while satisfying the UCS lower limit (27.6 Mpa) mentioned by ACI as a minimum requirement for RCC used in pavement construction. Moreover, UCS of RAP incorporated mixes, dissimilar to that of control mixes, was found to be sensitive and insensitive to the testing temperature and curing time after 7 days, respectively. The results also demonstrate that the higher amounts of RAP, the more flexibility in RCC is. This issue was also proved by the results of modulus of elasticity test. In addition, the toughness index (TI) shows that increase in RAP content leads to up to 43% increase in energy absorbance capacity of RCC.

• 한국응용과학기술학회지
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• 제34권4호
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• pp.756-768
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• 2017

본 연구는 50대 비만중년여성을 대상으로 순환운동이 건강체력, 혈압 및 혈관탄성도에 미치는 영향을 규명하는데 있었으며, 이를 위해 비만중년여성 24명을 대상으로 운동그룹 12명, 대조군 12명으로 분류하여 8주간 순환운동 프로그램을 실시하였다. 순환운동 프로그램은 유산소 운동과 저항운동으로 구성되었으며, 회당 40분간, 주3회 실시하였고, 유산소 운동 수행강도는 50-70% HRmax, 저항운동은 1-RM의 40-60%로 수행되었으며, 순환운동 전 후에 측정한 자료의 그룹 내 차이 비교를 위해 대응표본 T검정, 그룹 간 차이는 운동 전 후의 변화율을 산출하여 독립표본 T검정을 실시하였다. 그 결과 운동그룹은 건강 체력 중 BMI(p<.05)가 유의하게 감소하였고, 심폐지구력(p<.001), 근지구력(p<.001), 유연성(p<.01)이 증가하였으며, 그룹 간 대조군 보다 심폐지구력, 유연성이 유의하게 증가되었다(p<.01). 수축기 혈압과 이완기 혈압은 운동그룹이 유의하게 감소하였으며(p<.01), 이완기 혈압은 그룹 간 대조군 보다 운동그룹이 유의하게 감소하였다(p<.05). PWV는 운동그룹이 유의하게 감소하였고(p<.05), 대조군이 유의하게 증가하였으며(p<.01), 그룹 간 대조군 보다 운동군이 유의하게 감소하였다(p<.05). 이상의 결과 비만중년여성의 건강증진 및 비만치료를 위한 순환운동은 건강체력, 혈압 및 혈관탄성도에 긍정적인 영향을 미친 것으로 사료된다.