• International Journal of Aerospace System Engineering
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• 제6권1호
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• pp.1-7
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• 2019

In the present study, structural safety and stability on the main wing and tail planes of the 1.2 ton WIG(Wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The carbon-epoxy composite material was used in design of wing structure. The skin-spar with skin-stressed structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, the design load was estimated with maximum flight load. From static strength analysis results using finite element method of the commercial codes. From the stress analysis results of the main wing, it was confirmed that the upper skin structure between the second rib and the third rib was unstable for the buckling load. Therefore in order to solve this problem, three stiffeners at the buckled region were added. After design modification, even though the weight of the wing was a little bit heavier than the target weight, the structural safety and stability was satisfied for design requirements.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1233-1246
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• 2008

This study examines characteristics of people who are experiencing severe hair loss problems. We focus on how these characteristics are related to their psychological problems, hair loss treatments, wig-wearing practices, and life styles. We gathered survey data from people who visited wig shops for their hair loss problems. The study shows that men and women have different characteristics in every aspect we consider.

• 한국항공우주학회지
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• 제32권8호
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• pp.37-46
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• 2004

지면효과의 여러 현상을 Navier-Stokes 방정식을 이용하여 해석하고 공기역학적인 관점에서 그 결과를 분석하였다. 2차원 지면효과에 대해서는 이미지 와류에 의한 약형 표면의 압력변화, 두께의 영향, 지면효과의 비점성 유동 현상 등을 확인하였으며, 3차원 지면효과로 익단와류 강도의 증가현상과 유효스팬 증가, 익단와류의 바깥 흐름현상 등을 확인하였다. 또한, 재래식 익형인 NACA 6409와 러시아의 WIG기 전용익형인 DHMTU 8-30에 대해서 Irodov의 조건식을 사용하여 새로 정안정성을 해석하였다. 해석결과, DHMTU 8-30 익형의 세로 정안정성이 NACA 6409 익형보다 훨씬 우수한 것으로 나타났다. 그러므로 DHMTU 8-30을 WIG기에 사용할 경우 NACA 6409에 비해 꼬리날개 부피비를 현저히 줄일 수 있음을 확인하였다.

• 대한조선학회논문집
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• 제48권5호
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• pp.381-389
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• 2011

In this study, we are focusing our attention on lift characteristics of the low aspect wings for Wing-In Ground effect crafts (WIG). Experimental measurements at an open-type wind tunnel are carried out and results are comparatively presented. In order to simulate the realistic ground condition in where the WIG craft is flying, moving ground is implemented by a conveyor belt rotating with the same velocity of the inflow. We consider two different wings (NACA0012 and DHMTU section) which have four different aspect ratios (0.5, 1.0, 1.5 and 2.0). Forces acting on the wings are measured and lift characteristics are elaborately investigated for various different conditions. In addition, end-plate effects are estimated. Results are validated by comparing with theoretic solutions of the symmetric airfoil. Present results show that ground effects are differently generated in moving or fixed ground conditions, and hence left characteristics are affected by the ground condition. Consequently, accurate aerodynamic forces acting on the WIG craft are guaranteed in a realistic moving ground condition.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.179-184
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• 2005

In the present study, conceptual design of the main wing for 20 seats WIG{wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The high stiffness and strength Carbon-Epoxy material was used for the major structure and the skin-spar with a foam sandwich structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, firstly the design load was estimated with maximum flight load, and then flanges of the front and the rear spar from major bending load and the skin structure and the webs of the spars were preliminarily sized using the netting rules and the rule of mixture. In order to investigate the structural safety and stability, stress analysis was performed by Finite Element Codes such as NASTRAN/PA TRAN[6] and NISA II [7]. From the stress analysis results, it was confirmed that the upper skin structure between the front spar and rear spar was very unstable for the buckling. Therefore in order to solve this problem, a middle spar and the foam sandwich structure at the upper skin and the web were added. After design modification, even thought the designed wing weight was a little bit heavier than the target wing weight, the structural safety and stability of the final design feature was confirmed. Moreover, in order to fix the wing structure at the fuselage, the insert bolt type structure with six high strength bolts was adopted for easy assembly and removal.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.7-12
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• 2007

본 연구에서는 선행연구에 의해 설계되어진 20인승급 소형 위그선의 주날개 구조를 엔진 및 프로펠러에 의해 유발되는 진동을 가진력으로 하여 강제진동 해석을 수행하였다. 대상 위그선은 왕복엔 진을 날개에 장착하여 프로펠러에 의한 추력으로 비행하며， 미는 형식(Pusher Type)의 엔진 배열을 취하고 있다. 유한요소해석을 위해서 구조해석 상용프로그랩인 MSC/NASTRAN을 사용하였으며， 엔진의 주요 진동 특성인 X-mode 와 Y-mode 그리고 Z-mode를 특정 가진 주파수로 하여 주파수 응답 해석을 수행하였고, 엔진의 추력방향 진동 모드인 X-mode를 프로펠러의 회전에 의해 진동을 수반하는 가진 추력으로 가정하여 과도응답 해석을 수행한 후 날개의 진동 특성을 살펴보았다.

• 복식
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• 제60권5호
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• pp.51-70
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• 2010

The ritual to change the hairstyle holds the same meaning as the coming of age ceremony. The ceremony was performed throughout three times including choga, jaega, and samga. The garment and hairstyle attuned to the ceremony formalities. Women in the royal family had 'su-siK when they were fully grown up during choga, 'gwang-sik' during Jaega, and 'keun-meo-ri (big hairstyle)' during samga. 'su-sik' is the noblest hairstyle according to social status, which is allowed to be worn only by spouse of king and prince, regardless of adult or not. During jaega, 'gwang-sik' which was 'u-yeo-meo-ri', is made by winding 'darae (wig)' around a jjok-jin-muri (bun) [Jo-jim-meo-ri]? which distinguished the hairstyle of unmarried women, who did not go through a coming of age ceremony yet. Unmarried women maintained a hairstyle which is mostly twisted into one string, but they had 'saeang-meo-ri' when they were prepared for ceremonial costumes. Also, they had 'ga-raemeo-ri' when growing further. keun-meo-ri during samga is an addition of keun-meo-ri chaebal(wig) onto u-yeo-meo-ri. Women in the royal family made geo-du-mi by adding keun-meo-ri, which is formed by twisting wig, and oimyeongbu (noble ladies) and sanggung (court ladies) added a wooden wig called u-yeo-mi. Also, yeoryeong wore ga-ri-ma. In this way, the types of hairstyles were distinguished according to hierarchy. As the coming of age ceremonial dress. Wonsam was worn. During choga. wonsam was worn as a formal dress and during jaega and samga wonsam was worn as a full dress.

• 산업융합연구
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• 제20권6호
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• pp.117-123
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• 2022

4차 산업혁명시대를 사는 현대인에게 경쟁력과 직결되는 외모는 필수적 자기관리 중 하나로 정착한 가운데 탈모는 헤어스타일 연출의 위해요소로 작용한다. 이렇게 고통 받는 고객을 위한 보다 실용적이고 편리한 가발 제작을 목적으로 정보검색 포털사이트를 통해 연구 대상의 자료를 수집했으며 키워트와 키프리스를 통해 특허출원 동향을 검색하여 가발기술의 시대별 특허동향과 국내 굴지 가발업체의 신소재 개발 동향에 대해 분석하였다. 연구결과 2005년 이전은 가발의 부착과 결속기술, 2006년에서 2013년경은 가발의 인조 모발 관련 제조기술, 2014년 이후는 기능성 관련 가발 기술이 다수 출원된 것으로 나타났다. 그리고 H사와 M사 모두 각자의 특성을 지닌 형상기억 소재와 나노스킨의 신소재 개발 동향을 나타냈다. 본 연구는 가발 산업시장에서 고객에게 편안하고 간편한 착용감을 제공하면서 고객만족까지 도출할 수 있는 기능성 가발 개발의 기초자료로 제공되리라 사료한다.

• 대한조선학회논문집
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• 제44권2호
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• pp.180-188
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• 2007

In this paper the longitudinal control problem for the large WIG(wing-in-ground effect) craft is considered in the sense of the control augmentation system(CAS) derived by control surface of elevator. In order to achieve longitudinally stable systems, two modes of CAS are applied to the control systems which are pitch rate hold mode and pitch hold mode for steady flight. Since the employed CASs include the dynamic properties of the actuator time delay and the low pass filter, it provides the possible solution to be applicable to real systems. Nonlinear model simulations are fulfilled to investigate the effectiveness of the applied CASs with wind disturbance.

• 전기학회논문지P
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• 제57권2호
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• pp.192-197
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• 2008

The value of this paper is to use reduced size apparatuses to perform field measurement in order to identify and validate that the harmonic-current effects are due to the presence of self-excitation capacitance connected at stator's terminals of the studied SEIG. This paper has presented the measured electrical quantities of a three-phase $\Delta$-connected wind induction generator (WIG) under sudden connection and disconnection of resistive loads. An intelligent power-system recorder/monitor has been employed to measure three-phase voltages and currents of the studied system at the terminals of the studied WIG and the load. The measured electrical quantities have been analyzed. Total harmonic distortion (THD) of current using cumulative probability density function has been employed to determine the penetration of harmonic distortion at load side. The results show that the harmonic currents generated by the studied WIG can be severely amplified by the connected self-excited capacitance at the stator's terminals.