• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.11
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• pp.1291-1299
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• 2003

In order to design the better brassiere in terms of appearance and functions, various parameters of the materials should be considered; in this study, fatigue properties and subjective sensation of wing materials and its relation to the preference for a brassiere was investigated. After the survey of commercially available products, five elastic fabrics such as cotton, Modal, polyester, nylon, and Tactel, all of which contain 10% polyurethane, were chosen as specimens. Fabric growth were determined to evaluate fatigue properties. Qmax was determined to evaluate the warm-cool feeling. For the sensory test, semantic differential scale which contains 15 adjectives were developed. Fatigue properties were very similar at the 20% elongation irrespective of the duration of tension, but at 40% and 100% elongation, man made fabric showed less growth than cellulose fabrics. The factor analysis showed four factors such as sense of warmth, smoothness, weight and elasticity. Preference of the specimens was ranked in the order of Tactel>Modal>cotton>nylon>polyester.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.10
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• pp.896-901
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• 2015

The skin-frame type structure is designed to investigate the thermal deformation of the wing skin induced by the temperature gradient. In order to effectively simulate the temperature gradient on the wing specimen, a water cooling system is devised on the frame of the specimen. Out of surface skin deformation of the skin-frame type structure made of SUS304 material with respect to the temperature is successfully measured using the digital image correlation (DIC) technique including quantitative evaluation of the measurement uncertainty.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.150-152
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• 2008

사회가 발달하여 감성사회로 접어들면서, 섬유산업도 새로운 감성소재를 개발하기 위한 연구를 추구하고 있다. 이러한 분야의 연구수단으로 생체모방(Biomimetics)을 활용하는 연구개발이 활발히 진행되고 있는데, 이중 미래지향적인 차세대 섬유로 Morphotex(R)를 이용한 Morpho 직물이 있다. 감성소재분야에서 '구조발색섬유'라고 불리어지는 독특한 색미를 가진 섬유소재인 Morphotex$^{(R)}$는 남미의 MORPHO 나비 날개의 구조적 발색원리를 모방하여 만든 광발색섬유로 염료와 안료를 사용하지 않는 친환경섬유이면서 고기능성과 쾌적성을 겸비한 소재로 요즘 많은 각광을 받고 있다. 본 연구에서는 구조발색 소재를 이용하여 제직한 감성의류소재 직물의 감량조건에 따른 감성특성을 비교.분석해보았다. 먼저 구조발색 소재로 제직 된 직물의 감량공정특성에 따른 구조발색 소재 직물의 인장 인열 특성을 분석하였으며 또한 KES-FB system으로 구조발색 소재 직물의 역학특성을 측정하고 측정한 역학특성으로부터 감성태를 평가해 보았다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.692-697
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• 2005

A canard type aircraft, which has good wing stall and stall/spin proof characteristics, is being developed. The previous first and second prototypes, having full depth core sandwich type wing and fixed landing gear, was built for test flights. Newly developing Firefly will be equipped with retractable landing gear and conventional foam core sandwich laminate for wing and fuselage. For manufacturing, composite material process has been studied including coupon tests. Wet lay-up onto foam core with glass fabric using lay-up mold has been chosen, and composite material parts are cured under room temperature and atmospheric pressure condition. In general, molded parts show so good surface smoothness and standardized quality that are best in mass production. In this study, we present the mold technology and development status for small aircraft firefly.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.445-452
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• 2017

The wing leading edge skin in this research is an essential structural factor for improving wings' aeromechanical functions, protecting the interior elements of the wings from external damage including birds, and navigating planes safely. The study compared and reviewed models manufactured for optimal light-weight wings of composite UAVs. It compared and investigated displacement forms of torsion loads through finite element analysis using MSC. Patran/Nastran. By confirming the improvement of light-weighting performance according to lamination type, thickness change and shape through torsion strength tests of each model, the research suggested the optimal light-weight wing leading edge skin for small composite UAVs.

• Journal of Aerospace System Engineering
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• v.10 no.4
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• pp.50-58
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• 2016

In our preceding study, we reported that the use of light, composite-material wings in long-endurance Solar-Powered UAVs is a critical factor. Ribs are critical components of wings, which prevent buckling and torsion of the wing skin. This study was undertaken to design and manufacture optimal composite ribs. The ribs were manufactured by applying laminated-layer patterns and shapes, considering the anisotropic properties of the composite material. Through the finite element analysis using the MSC Patran/Nastran, the maximum load and the displacement shape were identified. Based on the study results measured by structural tests, we present an optimal design of ribs.

• Korean journal of applied entomology
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• v.39 no.1
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• pp.31-41
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• 2000

Community analysis of oribatid mites was conducted in Namsan and Kwangreung coniferous forests which have been received by different degrees of environmental pressures through urbanization processes. Oribatid mites were sampled in the litter and soil layer of study sites from May 1993 to October 1994. Although two sites have been under similar weather condition, seasonal changes in oribatid mites density did not show a synchronized pattern. Density in spring and summer showed stable pattern with low fluctuations, but unstable pattern in autumn between 1993 and 1994. And these patterns were highly correlated with precipitation. The density and species number were higher in the litter layer than in the soil layer and showed no typical seasonal changes. The dominant species were Scheloribates latipes (1 l.78%), Pergalumna altera (8.92%), Eohypochthonius crassisetiger (7.58%), Scheloribates sp. (6.89%) and Suctobelbella yezoensis (5.04%) in Namsan, and Ceratozetes japonicus (25.72%), Punctoribates punctum (14.15%), Trichogalumna nipponica (10.96%) and Ramusella sengbuschi (5.08%) in Kwangreung. The number of species with high constany were 10 and 18 in Namsan and Kwangreung, respectively. Namsan showed the feature of urban forests. In analysis of species diversity, species richness was significantly higher in Kwangreung than in Namsan, while shannon (H') and evenness index (J') were higher in Namsan than in Kwangreung. The values of shannon index (H') in Namsan and Kwangreugn were 2.83 and 2.62, respectively and evenness index (J') were 0.78 and 0.67, respectively. The value of similarity index between two sites was 0.68.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.699-705
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• 2015

Aircraft needs high lift-to-drag ratio and weight reduction of the structure for long endurance flight with a small power. Generally high aspect ratio wing is applied to HALE(High Altitude Long Endurance) aircraft. Also high modulus, and high strength CFRP(Carbon Fiber Reinforced Plastic) has been used in primary structures. and thin mylar(membrane material) film has been applied to skin of wing. As a result, wing is more flexible than the other structures. and the stiffness of thin mylar film has an affect on dynamic stability. In this study, the membrane characteristic of mylar film has been simulated using nonlinear gap elements. And equivalent modeling method using shell elements is presented using the nonlinear simulation result. The linear equivalent model has verified using the results of nonlinear membrane method. Proposed linear equivalent shell model has applied to mode analysis for estimate the effect of mylar mechanical properties on natural frequency.

• Food Science and Preservation
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• v.30 no.2
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• pp.358-368
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• 2023

Euonymus alatus (Thunb.) Sieb., also known as the arrow tree in Korea, is a plant in East Asia used in traditional medicine and food. In particular, the wings of E. alatus are rich in phenolic compounds. This study evaluated the antioxidant, α-glucosidase inhibition, and anti-cancer activities of E. alatus wing extracts. The radical and hydrogen peroxide scavenging acitvities and reducing the power of 1,000 ㎍/mL E. alatus wing extracts, were similar to those of the positive control (0.1% BHT, 0.1% α-tocopherol). In addition, ethanol and methanol extract at 250 ㎍/mL showed 95.70 and 94.99% of α-glucosidase inhibition activity, respectively. The ethanol extract of E. alatus wings had the highest total polyphenol and flavonoid contents (867.8 mg% and 521.7 mg%, respectively). The E. alatus wing extracts significantly decreased the cell viability of LNCaP human prostate cancer cells (p<0.001), MDA-MB-231 human breast cancer cells (p<0.001), and HT-29 human colon cancer cells (p<0.001) in a dose-dependent manner. However, there was no significant effect on B16 mouse melanoma cells. Notably, the ethanol extracts showed higher cancer cell growth inhibitory activity in LNCaP and HT-29 cells than the other extracts. These results suggest that E. alatus wing extracts could have significant clinical applications, and our results can be used as basic data for future functional food material development.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.67-72
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• 1995

본 연구에서는 섬유강화 복합재료로 구성된 항공기 날개를 외팔보 형태 구조물로 모델링하고 동특성 해석을 위해 횡전단변형 이론과 고전 적층판 이론을 적용, Rayleigh-Ritz 방법에 의한 진동해석을 수행한뒤 진동 발생시 효과적으로 제어할 수 있는 방법을 제시하고 시뮬레이션을 통하여 동특성 향상을 정량적으로 제시하였다. 진동을 제어하기 위한 방법으로서 수동적, 능동적 방법을 모두 사용하고 있는데, (보다 자세한 사항은 참고문헌[12] 참조) 본 연구에서는 TMD(Tuned Mass Damper)를 사용하지 않고 복합소재 구조물의 성질을 이용한 탄성배열설계(Structural Tailoring)로 수동적 의미의 면진효과를 거둘 수 있게 하였다. 능동 제어의 경우 되먹임(feedback) 제어기를 이용, 이산(discret) 작동기(actuator)를 통하여 외팔보의 휨 및 비틀림 모우드를 함께 제어하여 효과적인 제어기를 설계하였다.