• Title/Summary/Keyword: HAM-D

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Design and Characteristics of Linear Motor Damper for Vibration Control (진동제어용 리니어 모터 탬퍼의 설계 및 특성)

  • Jang, S.M.;Jeong, S.S.;Park, H.D.;Ham, S.Y.;Kim, H.I.
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.880-882
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    • 2001
  • A moving-coil-type linear oscillatory actuator is consisted of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure and an iron core as a pathway for magnetic flux. The inductance of moving coil and the push/pull effect is obtained from the permeance model of LOA with the open magnetic circuit. The analytical method are verified using the 2D finite element method.

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An Analysis on Volumetric Displacement of Gerotor Pump/Motor Using Vane Length (회전날개 길이를 이용한 제로터 펌프/모터의 배제용적에 관한 연구)

  • Kim, S.D.;Kim, D.M.;Ham, Y.B.;Han, C.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.8 no.2
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    • pp.8-16
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    • 2011
  • It is hard and complicated to analytically derive the volumetric-displacement formula of a gerotor pump/motor. Analytical formulas for calculating the volumetric-displacement are derived in this work, which is relatively easy and based upon vane lengths. The vane lengths mean the distances from axis of inner rotor or outer rotor to contact points between inner and outer rotors. Two kinds of formula were studied for two different kinematic motions of rotors. The first one is the case that outer rotor is fixed in space and inner rotor is in mixed motion of planetary revolution and rotation with respect to the spinning axis. And the second is the case that both inner and outer rotors simultaneously rotate. The proposed formula is verified through comparison with volumetric-displacement obtained from numerical CAD calculation.

3D Distance Measurement of Stereo Images Using Web Cams (웹 캠을 이용한 스테레오 영상의 3차원 거리 측정)

  • Kim, Seung-Hwan;Ham, Woon-Chul
    • IEMEK Journal of Embedded Systems and Applications
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    • v.3 no.3
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    • pp.151-157
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    • 2008
  • In this paper, we propose a three dimensional distance measurement method for a stereo system by using web cams. Using a parallel stereo system, a robot gets two images from each webcam and equalize brightness of both images. And we suggest an image processing method such as labeling, isolating an object from background and finding center of an object. We also propose a method of calculating the focal distance by using least square algorithm based on triangulation and we can reduce calculation error by this method. From experimental results, we show that the proposed method can be effective for 3D distance measurement.

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Pharmaco-Constituents of Korean Cultivated Rhubarb Leaves -The Anthraquinones from Leaves- (한국산 재배대황엽의 약효성분 -엽의 안트라퀴논-)

  • Ham, In-Hye;Kim, Il-Hyuk
    • YAKHAK HOEJI
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    • v.38 no.4
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    • pp.410-417
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    • 1994
  • As one of the studies for Korean cultivated Rhubarb, which has been used stomachic bitter, laxative and purgative, etc, MeOH extract of the leaves was fractionated with ether, ethylacetate. From the ether fraction of MeOH extract, two anthraquinone derivatives, 1,6,8-trihydroxy-3-methyl anthraquinone(emodin, $C_{15}H_{10}O_5$), 1,6,8-trihydroxy-3-hydroxymethyl anthraquinone (citrerosein, $C_{15}H_{10}O_6$) and from the ethyl acetate fraction of MeOH extract, one anthraquinone derivative, emodin-8-${\beta}$-D-glucopyranoside$(C_{21}H_{20}O_{10})$ were isolated and identified through the physico-chemical properties and spectroscopic evidences(UV, IR, NMR, Mass), respectively.

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Fine resolution patterning aided by inkjet printing (미세패턴 구현을 위한 잉크젯 응용 기술)

  • Shin D.Y.;Kim D.S.;Ham Y.B.;Choi B.O.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.587-588
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    • 2006
  • Drop-on-Demand (DOD) inkjet printing technology, especially piezo-typed, has been paid attention by industries due to its inherent nature of unbeatable material usage and low cost manufacturing cost. Despite of these key advantages over any other competing manufacturing technologies, the primary disadvantage has been considered as its limited capability to produce fine resolution patterns with a commercially available DOD inkjet print head. Although the main effort has been focused on the production of a DOD inkjet print head with smaller nozzles to overcome this challenging issue, an alternative approach could be taken and it would enable to expand the employment of DOD inkjet printing technology to applications requiring fine patterns further more.

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Slope terrain Analysis by using Terrestrial LiDAR Equipment (지상라이다 장비를 이용한 사면지형분석)

  • Ham, Ju-Hyoung;Choi, Seung-Pil;Kim, Mun-Sup;Kim, Uk-Nam
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.291-293
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    • 2010
  • Terrestrial LiDAR can be used to accurately measure the 3D slope terrain because it can obtain the entire shape of the object, instead of only a specific location, while not much influenced by the environment, and it can create more dense and precise 3D coordinates than those of aerial LiDAR. Therefore, in this study, subject areas with different terrain conditions were selected, the terrestrial LiDAR device was used to observe the slope terrain, and a slope terrain analysis technique was proposed based on the observation results.

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A Basic Study on the Development of Simulation Systems for Supporting the Pre-design Phase of Construction Projects (건축 기획 지원 시뮬레이션 시스템 개발에 관한 기초 연구)

  • Min, Kyung-Min;Ham, Nam-Hyuk;Kim, Joo-Hyung;Kim, Jae-Jun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.176-181
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    • 2007
  • The widespread of IT technology caused a remarkable change in many industries and the construction industry is also one of them being influenced in the form of CIC(Computer Integrated Construction) and BIM(Building Information Modeling). Construction projects have many participants from various disciplines involved throughout the entire process. Therefore the success of the project greatly depend on the efficiency of decision-making using the information generated from each process stage. Looking from this aspect, the greatest potential value lies in the planning and pre-design stage when considering the construction life cycle. In this paper, we propose a project on developing a 3D object oriented simulation system for supporting the pre design phase. We define the needs for such system through previous case studies and suggest a to be process model. Finally we anticipate the effects that the project will eventually contribute to the construction industry.

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An Analysis on Volumetric Displacement of Hydraulic Gerotor Motor (제로터 유압 모터의 용량에 관한 연구)

  • Kim, D.M.;Ham, Y.B.;Kim, S.D.
    • 유공압시스템학회:학술대회논문집
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    • 2010.06a
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    • pp.39-43
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    • 2010
  • It is hard and complex to analytically derive a volumetric displacement formula of a gerotor hydraulic motor because geometric shape of its rotors is complicate. An analytical method about the volumetric displacement is proposed in this work, which is relatively easy and based upon two physical concepts. The first one is energy conservation between hydraulic input energy of the motor and mechanical output energy. The second concept is torque equilibrium with respect to inner and outer rotors. The proposed formula about the volumetric displacement is verified by comparing an analytical displacement and a numerical displacement for an example specification of the motor. The numerical displacement is calculated through a kind of CAD technology. The analytical formula can be utilized in analysis and design of hydraulic gerotor motors.

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