• Journal of Korea Fair Competition Federation
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• no.142
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• pp.26-37
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• 2009

• Proceedings of KHEA Conference
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• 2003.10a
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• pp.134-134
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• 2003

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.160-165
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• 2022

In this paper, we have proposed a magnetic resonant 6.78MHz WPT(wireless power transfer) technique which can be applied to a fixed transmitter and a receiver of varying relative distance and coil alignment, Power transmission characteristics are studied with the relative distance and misalignment ration of coil area between the transmitting and receiving coils. The coils are designed with the size of 60×80mm² by direct feeding method, and the characteristics are derived with the maximum relative distance of 50mm and horizontal area misalignment state of 0-40mm misalignment of coil center axis in the XY plane. The power transmission characteristics are compared between the 3D EM simulation and the measured data, and the power transmission shows larger than -3dB performance with the vertical distance of up to 30mm and 50% area misalignmment ratio. This work showsthe transmission characteristics according to relative distance and misalignment state between the cols and that direct feeding has advantage for the short relative distance and small misalignment ratio.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.1
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• pp.59-65
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• 2019

In this study, optimal design of direct-drive VCMs (Voice Coil Motor) for a missile fin actuator is carried out. The torque performance and the characteristics of the VCM are predicted by commercial electromagnetic analysis software, ANSYS Maxwell. The optimal design is obtained at the minimum and maximum actuating angles where the aerodynamic load acting on the fin is the largest in the operating range. The critical variables of the actuator is designed and the RSM (Response Surface Method) is used for the optimization. The response surface model consists of second-order functions and its experimental points are selected by a central composite design. This design is widely used for fitting a second-order response surface. The adjustment regression coefficients is computed for adequacy checking of the response surface model. Finally, the torque values obtained by the RSM and the ANSYS Maxwell are shown in good agreement.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1831-1838
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• 1991

The deformation of coil spring with noncircular section, which is used in the engine valve of automobiles under the applied load is usually accompanied by sectional warping and additional displacements of geometric center. In this study the isoparametric beam element formulations are modified and expanded to consider these two effects. To verify these formulations, simple torsion tests are made and compared with the analysis results. For the case of the zero-pitch spring, the stress distributions of oval and circular section are coincided with those of the analysis using the solid elements. Cylindrical coil springs with oval section are analyzed. These results are agreed with those of Nagaya.

• Journal of the Korean Magnetics Society
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• v.2 no.2
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• pp.132-139
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• 1992

We have designed a magnetic field gradient useful for cylindrical imaging in NMR-CT. The direc¬tion of the designed field is parallel to the axis and the gradient in the radial direction of cylindrical coordinate is monotonically increasing. The ratio of the gradient in the radial and axial direction is greater than 10 near the center of coordinate. This ratio depends on solenoid length, the number of reverse current turns at center, and the amount of the reverse current. We built a gradient coil based on the numerical simulation and tested the field generated by NMR-CT. The resulting image matches with the theoretical expectation within 10% error. Since the data acquisition time of 1-D imaging is significantly shorter than 2-D imaging, it becomes possible to image much more dynamic objects by the use of this gradient field.

• Distribution Business Review
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• no.2
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• pp.105-116
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• 2002

유통업도 이제는 제조업과 마찬가지로 국경의 개념이 허물어지고 있다. 무역자유화와 더불어 해외투자가 자유화되면서 유통기업들도 해외에 진출하여 영업 반경을 넓히고 있다. 우리나라에서도 지난 1996년 유통업에 대한 외국인 투자가 자유화됨에 따라 까르푸(Carrefour), 월마트(Wal-Mart), 테스코(Tesco), 코스트코 홀세일(Costco Wholesale)과 같은 굴지의 다국적 유통기업들이 국내에서 영업하고 있다. 전통적으로 유통업은 내수 위주의 산업으로 지역 소비자와 밀접한 관계를 유지해야 하기 때문에 해외 진출에 소극적이었으나 최근 유럽 및 미국 업체들을 중심으로 동남아 및 남미에 대한 진출을 확대하고 있다.(중략)

• The Safety technology
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• no.194
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• pp.16-17
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• 2014

광양제칠소 내에서 슬라브, 코일 등의 운송작업을 전문으로 하는 성암산업(주)은 중소기업을 의심케 할 정도로 체계적인 안전보건활동을 펼치고 있는 곳이다. 안전보건 전담 인원을 3명이나 배치한 것은 물론 안전을 기업경영의 핵심요소로 인식하고 다양한 안전보건활동을 펼쳐나가고 있는 것이다. 이 같은 안전경영의 중심에는 한승훈 대표 이사가 있다. 한 대표이사는 성암산업(주)에 취임한 후 바로 현장 속으로 들어가 근로자와 함께 현장밀착형 안전관리를 전개해나갔다. 그 결과 국내 내로라하는 기업들이 최고의 안전사업장이라는 명예를 걸고 치열한 경합을 벌였던 '2013년도 안전경영대상'에서 종합대상을 차지하는 영예를 얻었다. 안전경영으로 무재해 현장을 조성하고 있는 한승훈 대표이사를 만나봤다.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.387-388
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• 2014

본 연구는 살레시오회가 남수단에 운영중인 돈보스코마을학교 프로젝트의 교육콘텐츠를 중심으로 살펴보고 개선되어야 할 문제점에 대해 해결방안을 제안하고자 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.3
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• pp.250-256
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• 2002

In this paper, a broadband sleeve monopole antenna using a loading coil in sleeve is proposed. The center frequency of the proposed antenna is 1,990MHz. The antenna of the proposed structure has the same of the single sleeve monopole antenna, except for using the coil instead of the inner conductor in sleeve. As a result, it is found that the bandwidth is 1.239~2.154 GHz(above 53.9 %) for $S_{11}=-10\;d B$(VSWR<2), and the antenna impedance is good for a communication system and feeder which the impedance has 50 Ω.