• Proceedings of The KACE
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• 2017.08a
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• pp.197-199
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• 2017

재난 상황이나 우주 공간과 같은 환경에서는 인간이 직접 작업을 수행하기가 매우 어렵다. 따라서 이러한 환경에서 인명 구조나 탐사 등을 진행할 때에는 원격으로 제어가능한 로봇을 활용하는 것이 효과적이다. 특히 이 로봇이 인간의 움직임을 실시간으로 모방한다면 직관적이고 순발력 있는 제어가 가능해진다. 본 연구에서는 키넥트 센서를 이용해 인간의 움직임을 인식하고 이 움직임을 모방하는 로봇핸드와 로봇암을 구현하였다. 하드웨어는 TETRIX와 EV3 플랫폼을 이용하여 설계하였고, 소프트웨어는 C# 기반의 KINECT for Windows SDK와 Visual Studio 2015로 구현하였다. 본 연구에서 구현한 시스템은 재난 현장에서의 인명 구조, 복구 상황에서와 우주 공간에서의 탐사 상황에서 유용하게 사용될 수 있을 것이다.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.221-229
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• 2016

Fifty-five specimens of Octopus longispadiceus, belonging to the family Octopodidae, were collected for the first time from the East Sea of Korea and identified by DNA barcoding. This species is characterized by its long right third arm and ligula, the presence of enlarged suckers in the mature male, small white spots on the mantle, head, and arms, and no cirrus above the eye. A molecular analysis of the partial cytochrome c oxidase subunit I gene showed that these specimens are all the same species and have the smallest genetic distance with O. longispadiceus (Kimura- two-parameter distance = 0.002-0.003). A new Korean name, "Bal-mun-eo" is proposed for this species.

• Journal of the Korean Society for Heat Treatment
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• v.31 no.3
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• pp.97-103
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• 2018

The objective of this study is to develop the mechanical properties of AlSiCu aluminum alloy by the two-step solution heat treatment. The microstructure of gravity casting specimen represents a typical dendrite structure having a secondary dendrite arm spacing (SDAS) of 40 mm. In addition to the Al matrix, a large amount of coarsen eutectic Si phase, $Al_2Cu$ intermetallic phase, and Fe-rich phases are generated. The eutectic Si phases are fragmented and globularized with solution heat treatment. Also, the $Al_2Cu$ intermetallic phase is resolutionized into the Al matrix. The $2^{nd}$ solution temperature at $525^{\circ}C$ might be a optimum condition for enhancement of mechanical properties of AlSiCu aluminum alloy.

• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.4
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• pp.726-736
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• 2018

This study determined how the upper body shape of elderly women changes with age in order to improve the fit of clothing worn by elderly women. Thirty-nine healthy elderly Japanese women had their body measurements taken by measuring tape and a 3D body line scanner (Hamamatsu Model #C9036-02) from December 2011 to March 2012 at a university in Tokyo. It was found that the shoulder line shortens in women between the ages of 70 and 74, but that the upper arm lengthens in women between the ages of 75 and 79. It was also found that the upper part of the scapular area rolls forward in women between the ages of 70 and 74, and that the point of the back which protrudes the most-the lower scapular area-rolls forward in women between the ages of 75 and 79. The results will be helpful for designing clothes for elderly women as their body shape changes with age.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.133-140
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• 1993

In this paper, we prpose a method for tracking optimally a spatial trajectory of the end-effector of flexible robot arms with multiple joints. The proposed method finds joint trajectories and joint torques necessary to produce the desired end-effector motion of flexible manipulator. In inverse kinematics, optimized joint trajectories are computed from elastic equations. In inverse dynamics, joint torques are obtained from the joint euqations by using the optimized joint trajectories. The equations of motion using finite element method and virtual work principle are employed. Optimal control is applied to optimize joint trajectories which are computed in inverse kinematics. The simulation result of a flexible planar manipulator is presented.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.164-170
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• 2003

To ensure the reliability of DVDR-P and DVD-ROM, it is imperative to remedy the unrecoverable creep deformation and/or relaxation of the holding force of an optical disc holder. To predict the deformation of an optical disc holder, a deformation analysis of an 80 mm optical disc holder considering the creep characteristics of 3 plastic materials has been conducted. Subsequently, the results by this Finite Element Analysis (FEA) are experimentally verified. A disc holder inserted in a cartridge case is kept in a chamber of $60^{\circ}C$ with 90 % humidity for 24 hours. The arm span and the holding force of the disc holder are measured after being left for another 24 successive hours at a room temperature and under normal humidity. The predicted results by FEA are in good agreement with experimentally measured values.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.10
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• pp.123-129
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• 1996

Computed torque method has been used for precise trajectory control of the robotic system that involves nonlinear dynamics. It is hard to know exact values of robot system parameters, and the robot arm receives umpredictable interference from the working environment. These disturbances, especially in a direct drive robot, are directly transmitted to actuating motor without reduction. Modelling error and distrubance can cause significant errors in a trajectory tracking problem. In this paper, we propose a new controller that $H_{\infty}$controller is conbined to robot system linearized by computed torque. Simula- tions are made for comparing the performance of the proposed controller with that of a nonlinear $H_{\infty}$ controller proposed by Chen and also computed torque method.hod.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.379-387
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• 2013

This paper describes a scheme of motor control for Quadcopter with Android phone instead of a dedicated controller. Basically, user's requests (channel and speed) are inquired and transferred to the Quadcopter with Android phone, then the embedded Linux system receives them and controls the motor speed of corresponding channel. We have designed and implemented an App. for user interface and the modules of device driver and timer ISR for the motor control. Finally, we have up-loaded the App. and the modules to an Android (ver.4.0) phone and ARM processor (S3C6410)-based embedded board respectively, and reviewed the functional correctness by testing the motor control of Quadcopter.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1097-1100
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• 2003

본 논문에서는 최근 유선을 대치하기 위해 등장한 여러 가지 근거리 무선통신 방식 중 블루투스 기술과 시스템의 안정성 및 리소스의 효율적 사용을 위한 멀티태스킹이 가능한 RTOS(uC/OS)를 이용하여 투선 비디오 도어폰을 설계 및 구현해 본다. 송신기는 카메라, 비디오 디코더, 영상 압축칩 프로세서(ARM7TDMI), 메모리, 블루투스 모듈 등을 이용하여 임베디드 시스템을 구성하였고, 수신기는 블루투스 모듈을 통해 수신된 영상 데이터를 모니터에 디스플레이 할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.5 no.4
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• pp.347-353
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• 1981

The surging stresses of the valve spring of over head valve 4 cycle engine, which is made is Korea, were computed from theoretical analysis and these values were compared with the experimental results. For calculating surging stresses of test engine valve spring. Kato's equation should be corrected by the corretion factor C which is equal to twice rocker arm level ratio. Good agreement was found to exist between the theoretical analysis and the experimental results within.+-.5 percent differences. The stress amplitudes of test valve spring at each harmonic order were determined by the experiment and by using corrected equation, The safety considerations of test valve spring were discussed.