• 제어로봇시스템학회논문지
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• 제6권10호
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• pp.881-887
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• 2000

There are significant nonlinearities and uncertainties in hard disk drive actuators. In particular, pivot bearing nonlinearity and repeatable run-out make track-following control difficult as track density increases. In this paper, we design a robust track-following controller using a robust deterministic control scheme in which the pivot bearing nonlinearity and repeatable run-out are considered as uncertainties. Simulation study is conducted to evaluate the control performance of the proposed control scheme.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.261-266
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• 2003

The present paper theoretically investigates characteristics of moment balance of a tilting-pad thrust bearing. Pressure of lubricant film of the bearing was computed using tile finite element method, and average film temperature was estimated from the heat balance over a pad. From the investigation, it has been found that different two sets of tilt angles satisfy moment equilibrium of the pad about tile pivot for a given pivot location. The tilt angles converged depend upon initial tilt angles assumed. Quite different bearing performance, including load capacity, film thickness, and temperature, is shown to be obtained based on choice of the initial tilt angles.

• Tribology and Lubricants
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• 제10권1호
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• pp.35-45
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• 1994

The thermohydrodynamic analysis of tilting pad thrust bearing is studied with the consideration of elastic effect of pad. Reynolds equation, deflection equation and energy equation are solved simultaneously with the boundary conditions. Reynolds equation is modified as the approximate form. Pads are supported by the line pivot and the point pivot respectively. Pads are considered as the flat planes. Effects of pad thickness on the performance of thrust bearing are emphasized and the performances of rigid pad and elastic pad are compared. Effects of inlet temperature on performances of the bearing are compared. Dynamic characteristics of both pad supported by line and point pivot are compared.

• International Journal of Aeronautical and Space Sciences
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• 제9권2호
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• pp.58-63
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• 2008

This paper describes aerodynamic performance enhancement of cycloidal rotor according to the blade pivot point movement and the blade preset angle adjustment. Cycloidal blade system which consists of several blades rotating about an axis in parallel direction and changing its pitch angle periodically, is a propulsion mechanism of a new concept vertical take off and landing aircraft, cyclocopter. Based on the designed geometry of cyclocopter, numerical analysis was carried out by a general purpose commercial CFD program, STAR-CD. According to tills analysis, the efficiency of cycloidal rotor could be improved more than 15% by the introduced methods.

• 복식문화연구
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• 제2권1호
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• pp.29-38
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• 1994

This research has been to perform with various methods of measurement of human body. As experiment methods, performed the body measurement method with Martin's measurer, took pictures for he observation of body gesture and body shape, and applied the cross-section measurement method of each body part for the making of body pivot. In the making of body pivot. used several sheets of styroform, and attached some gypsum power on the surface of the body pivot for he body silhouette of body. Eventhough, there were not enough subjects for this study, these methods will be continuously conducted with enough subjects, there will be to develop the body measurement method for Korean women, and will find to solve a suitable manufacturing body and the study of body for Korean women.

• 한국전자통신학회논문지
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• 제5권5호
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• pp.415-420
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• 2010

PC 성능의 향상 및 컴퓨터 그래픽스 기술의 발달로 인해 사회 각 분야에서 고품질의 컴퓨터 애니메이션이 점차 증가하고 있다. 본 연구에서는 해저의 풍경을 표현함에 있어 가장 핵심이 되는 어류 객체의 역동적이고 자연스러운 움직임을 표현하는 과정을 모핑 기법을 통하여 구현하기 위한 기준점 적용 보간법을 제안한다. 어류 객체의 꼬리 움직임에 적용시킴으로써 기존 모핑 기법이 가지고 있던 부자연스러운 속도감을 해결하고, 단조로운 움직임을 탈피한 현실감 있는 유영 방식을 구현한다.

• Tribology and Lubricants
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• 제20권3호
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• pp.152-156
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• 2004

The present paper theoretically investigates characteristics of moment balance of a tilting-pad thrust bearing. Pressure of lubricant film of the bearing was computed using the finite element method, and average film temperature was estimated from the heat balance over a pad. From the investigation, it has been found that different two sets of tilt angles satisfy moment equilibrium of the pad about the pivot for a given pivot location. The tilt angles converged depend upon initial tilt angles assumed. Quite different bearing performance, including load capacity, film thickness, and temperature, is shown to be obtained based on choice of the initial tilt angles.

• 항공우주기술
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• 제7권1호
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• pp.170-176
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• 2008

고체모터 추력제어를 위한 플렉시블 셀 개념 설계를 수행하였다. 개념 설계를 통해 플렉시블 씰의 구동 점 위치, 플렉시블 씰의 형상, 고무 및 보강재 소재를 결정하였으며, 연소가스로부터 플렉시블 씰을 보호하기 위한 적절한 열 차폐 시스템을 선정하였다. 플렉시블 씰의 회전 중심은 노즐 후방에 위치하며, 단면 형상은 원뿔형 으로 설계하였다. 노즐의 구동 토크를 만족하기 위해 고무의 전단 계수는 약 0.6MPa 이하가 되도록 개발 하였으며, 전단 응력은 2.5MPa 이상이다.

• 한방안이비인후피부과학회지
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• 제23권1호
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• pp.224-252
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• 2010

Objective : The purpose of this study is to investigate tinnitus of Plain Questions $\ll$素問$\gg$ and Miraculous Pivot $\ll$靈樞$\gg$. Methods : We conducted a study on the original text paragraphs of Internal Classic $\ll$內經$\gg$ containing the tinnitus and analysis of Yang, Ma, Zhang, Wang etc. We drew a parallel between tinnitus from Internal Classic $\ll$內經$\gg$ and matching diagnoses from western medicine. Results : The results were as follows. 1. Tinnitus in Plain Questions $\ll$素問$\gg$Tong Pyeong Heo Sil Ron <通評虛實論> was similar to the symptoms of diabetes mellitus complication and schizophreniform disorder in western medicine. 2. Liver fire tinnitus in Plain Questions $\ll$素問$\gg$ Yuk Won Jeong Gi Dae Ron <六元正紀大論> was similar to the symptoms of psychological distress in western medicine. 3. Phlegm fire tinnitus in Plain Questions $\ll$素問$\gg$ Ji Jin Yo Dae Ron <至眞要大論> was similar to the symptoms of meniere's disease and malfunction of autonomic nervous system in western medicine. 4. Blood deficiency tinnitus in Miraculous Pivot $\ll$靈樞$\gg$ Sa Gi Jang Bu Byeong Hyeong <邪氣藏府病形> was similar to the symptoms of anemia in western medicine. 5. Tinnitus in Miraculous Pivot $\ll$靈樞$\gg$ Gyeong Geun <經筋> was similar to the myofacial pain syndrome of the sternocleidomastoid muscle and the masseter muscle in western medicine. 6. Gallbladder deficiency tinnitus in Miraculous Pivot $\ll$靈樞$\gg$ Gwol Hyeong <厥病> was similar to the symptoms of otitis media and labyrinthitis in western medicine. 7. Kidney deficiency tinnitus in Miraculous Pivot $\ll$靈樞$\gg$ Gyeol Gi <決氣> and Hai Ron <海論> was similar to the symptoms of degenerative auditory organ in western medicine. 8. Tinnitus in Internal Classic $\ll$內經$\gg$ showed close relations with the symptoms of the wind character. Conclusion : We analyzed the original text paragraphs of Internal Classic $\ll$內經$\gg$ and explanations about tinnitus. Further studies are needed to compare oriental medicine and western medicine diagnoses to develop better treatments for tinnitus.

• 항공우주시스템공학회지
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• 제18권1호
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• pp.64-71
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• 2024

항공기 외부연료탱크는 항공기의 항속거리를 증가시키는 주요 구성품으로써, 비상시 파일런에서 안정적으로 분리될 수 있어야 된다. 이 때, 외부연료탱크의 핀(fin)과 피벗(pivot)에는 분리하중이 작용하게 되는데, 외부연료탱크의 안정적인 분리를 위해서는 핀과 피벗의 구조 건전성이 입증되어야 한다. 본 연구에서는 항공기로부터 외부연료탱크가 분리 될 때 외부연료탱크의 핀과 피벗의 구조건전성 검증을 위해 수행된 구조시험 결과를 제시하였다. 본문에서는 구조시험에 사용되는 유압 및 하중제어장비, 데이터 획득장치 그리고 공압공급장치로 구성되는 시험구성도를 설명하였고, 각 시험조건에 대한 시험설치와 시험하중 인가계획을 제시하였다. 구조시험 결과, 각 시험조건에서 시험하중과 시험체의 내부압력이 허용 범위 내에서 적절히 제어되는 것으로 파악되었고, 시험체에서도 심각한 구조적 결함이 발생하지 않았음이 확인되었다. 최종적으로, 설계 제한하중과 설계 극한하중에 대한 구조시험을 통해서 본 연구의 항공기용 외부연료탱크 핀과 피벗은 충분한 구조 강도를 보유하고 있음을 확인하였다.