• 항공우주기술
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• 제13권2호
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• pp.1-6
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• 2014

본 논문은 틸트-덕트 수직이착륙 비행로봇을 위한 동력계통의 설계, 개발 및 시험 결과를 기술한다. 본 연구에서는 R/C 모터보트에 적용되는 소형 수냉식 엔진을 이용하여 비행로봇의 탑재 및 비행체와 인터페이스에 대한 하드웨어 개발 사항을 기술하였다. 또한 지상시험과 안전줄 시험을 통해 비행체의 추력 성능을 측정하고 동력계통의 내구성 결과가 제시되었다.

• 대한기계학회논문집A
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• 제32권8호
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• pp.685-692
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• 2008

In this paper, the trajectory control problem of an underwater robot is addressed. From the viewpoint of control engineering, trajectory control of the underwater robot is not an easy task due to its nonlinear dynamics, which includes various hydraulic forces such as buoyancy forces and hydrodynamic damping, the difference between the centers of buoyancy and gravity, and disturbances from a tether cable. To solve such problems, we applied Time Delay Control to the underwater robot. This control law has a very simple structure not requiring the nonlinear plant dynamics, and was proven to be highly robust against disturbances and uncertainties. We confirmed its effectiveness through experiments.

• Journal of Mechanical Science and Technology
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• 제18권4호
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• pp.573-581
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• 2004

A self-contained wall climbing robot, called MRWALLSPECT (Multi-functional Robot for WALL inSPECTion) II, is developed. It is designed for scanning external surfaces of gas or oil tanks with small curvature in order to find defects. The robot contains all the components for navigation in itself without any external tether cable. Although it takes the basic structure of the sliding body mechanism, the robot has its original characteristic features in the kinematic design with closed link mechanism, which is enabled by adopting a simple and robust gait pattern mimicking a biological system. By employing the proposed link mechanism, the number of actuators is reduced and high force-to-weight ratio is achieved. This paper describes its mechanism design and the overall features including hardware and software components. Also, the preliminary results of experiments are given for evaluating its performances.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3254-3260
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• 2014

Intramolecular Diels-Alder (IMDA) reaction of vinylarenes bearing a Z-alkenyl tether, prepared from Morita-Baylis-Hillman (MBH) adducts, afforded arene-fused isoindoline derivatives in good yields. Vinylfurans, vinylthiophenes, and vinylnaphthalenes could be used successfully as dienes, while vinylbenzene failed under the same reaction conditions.

• 한국소음진동공학회논문집
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• 제21권5호
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• pp.416-421
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• 2011

The purpose of this study is to analyze nonlinear dynamics of a tethered satellite. The nonlinear equations of motion are derived by using Lagrange's equations with the polar coordinate system. In order to analyze the response of tethered satellite, time responses are computed by the Newmark's time integration method. This paper claims that the dynamic behavior of the system is changed by the effect of length of tether, mass ratio of satellites.

• 한국자동차공학회논문집
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• 제20권5호
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• pp.1-7
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• 2012

Automobile airbag deployment process has been studied with MADYMO software. Based on the FMVSS208 and USNCAP(United States New Car Assessment Program) regulations, four parameters were chosen for the design improvement with reference to the 5th percentile female passenger dummy: time to fire, vent hole size, tether length and tank test pressure of inflator. Sensitivity analyses based on orthogonal arrays show that enhanced protection of small females can be achieved with improved USNCAP rating within the boundary of FMVSS 208.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.187-188
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• 1998

A low cost, low power, portable cardiac event recorder as a tether-free biological signal processor was developed. Dual channel ECG signals are sampled at 128Hz in 12 bits resolution. Sampled data are continuously recorded in a circular buffer. If event button is pressed, 2 minutes data before and after the event are recorded in 512 Kbyte SRAM. Total 11 events can be recorded. Data can be transferred to PC through RS-232 protocol. It operates for two months by a half AA size 3.6V Lithium battery. The system size is $55\times55\times13[mm^3]$.

• 대한조선학회논문집
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• 제32권2호
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• pp.56-67
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• 1995

본 연구에서는 케이블 비선형 정역학 방정식의 해로서 선박-케이블-잠수체 시스템의 정적모양이 보여지고, 선형 운동 방정식의 진동수영역해석에 의해 고유진동수가 구해진다. 또한 긴 연직케이블의 스내핑 현상을 클리핑 오프(clipping-off) 수치모형으로 이상화하여 극단장력을 계산한다.

• 한국해양공학회지
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• 제7권1호
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• pp.62-72
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• 1993

This paper describes the results of 3 years project on the design and development of a 500 meter class ocean survery ROV model. The design concept and the design procedure are given for each component of the ROV model. The design concept and the design procedure are given for each component of the ROV. Special emphasis is laid on the development of the position control system together with the development of the performance evaluation technique.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.86-93
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• 2003

These days, automobile industry pays considerable attention to child occupant safety. As the US adopted requirements for universal and uniform anchor systems for child restraints, manufacturers for child seats put an enormous effort to improve the protective properties of Child Restraint System (CRS). Various standards have been studied and announced by different countries. The anchorage system is the most important in the CRS and the rules of universal anchor are to provide devices which are independent of safety belts. A new concept called International Standard Organization Fixture (ISOFIX) has been announced. It suggests some designs for the CRS. In this study, the suggested designs are evaluated with domestic products. Tests are performed and the results are incorporated into a finite element modeling process. As the finite element model is established, various numerical tests are conducted and the numerical results are discussed. A commercial software system is utilized for the nonlinear finite element analysis.