• Design & Manufacturing
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• 제9권2호
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• pp.34-37
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• 2015

The HEV Traction Motor Core manufacturing technology is a core component of HEV Traction Motor Core (Iron Core) is a key technology for the manufacture of eco-friendly automotive industry is essential for the competitiveness of the country must obtain the technology. In this study, the HEV Motor Core of the Rotor manufacturing technology, the Stator manufacturing technology applied to Press Lamination Die and Core(Iron Core) was developed and the results are discussed.

• 정보보호학회논문지
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• 제27권2호
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• pp.281-292
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• 2017

지속적인 북한의 사이버 공격에 대응해서 사이버 무기체계와 핵심기술의 연구개발 추진을 요구받고 있는 상황이다. 본 논문은 사이버 무기체계에 소요되는 핵심기술을 도출하고, 도출된 핵심기술들의 실현시기에 대한 영향 요인을 분석하였다. 9개의 핵심기술군, 36개의 핵심기술이 도출되었으며, 도출된 핵심기술군을 합동사이버작전교범의 작전단계와 록히드마틴의 사이버 킬체인과 비교해 본 결과, 누락된 요소가 없이 매핑되고 있음을 확인하였다. 핵심기술의 실현시기에 대한 각 요인별 영향도를 회귀분석한 결과, 핵심기술의 실현시기는 최고선진국 기술수준, 한국 기술수준, 국방에서 민간으로의 기술이전 가능성, 민간에서 국방으로의 기술이전 가능성이 높을수록 더 빨라지고, 선진국의 기술이전 기피도가 높을수록 더 늦어지며, 경제적 파급효과와는 유의미한 상관관계가 없는 것으로 확인되었다. 본 연구는 사이버무기 체계를 정식 무기체계로 편입시킨 전력발전훈령 개정 및 합참사이버작전교범 제정에 맞춰 사이버 무기체계의 핵심기술을 도출하고 핵심기술 실현시기의 영향 요인을 확인한 것에 의의가 있다.

• Fibers and Polymers
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• 제5권1호
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• pp.25-30
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• 2004

The present paper reports the impact of thermal treatment on the characteristics of core-sheath type hybrid technical yarns. The core-sheath type hybrid yams are prepared using DREF-III technology. Polyester and glass multifilaments are used as core components whereas the cotton and polyester staple fibers are the sheath components wrapped around the core filament with different proportions to form a hybrid structure. The thermal treatment is carried out both in dry and in wet state under relaxed condition and the thermal shrinkage, sheath-slipping resistance and tensile and bending properties of hybrid yarns have been studied. Thermal treatment markedly increases the thermal shrinkage and sheath-slipping resistance of hybrid yarns with polyester multifilament in core, but insignificant effect for yarns with glass multifilament in core. Breaking elongation of hybrid yams with polyester multifilament in core increases with treatment temperature. The hybrid yarns with glass multifilament in core are least affected by thermal treatment.

• Design & Manufacturing
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• 제9권1호
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• pp.9-13
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• 2015

The HEV/EV Traction Motor Core manufacturing technology is a core component of Traction Motor Core is a key technology for the manufacture of eco-friendly automotive industry is essential for the competitiveness of the country must obtain the technology. This study was performed to develop a Rotor Core of the HEV/EV Traction Motor using the first time in Korea multi-gate BMC injection molding technique. Executed by the experiment of this study are as follows. Study 1: Developed a multi-gate BMC injection mold for the magnet fixed to the Rotor Core. Study 2: Developed a production implementation and manufacturing technology of the Rotor Core. In this study, the develop products and manufacturing technologies implemented by the BMC injection mold development for Magnet fixed to the Rotor Core and the results are discussed.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.617-626
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• 2022

To effectively monitor the variety of distributions of neutron flux, fuel power or temperatures in the reactor core, usually the ex-core and in-core neutron detectors are employed. The thermocouples for temperature measurement are installed in the coolant inlet or outlet of the respective fuel assemblies. It is necessary to reconstruct the measurement information of the whole reactor position. However, the reading of different types of detector in the core reflects different aspects of the 3D power distribution. The feasibility of reconstruction the core three-dimension power distribution by using different combinations of in-core, ex-core and thermocouples detectors is analyzed in this paper to synthesize the useful information of various detectors. A comparison of multilayer perceptron (MLP) network and radial basis function (RBF) network is performed. RBF results are more extreme precision but also more sensitivity to detector failure and uncertainty, compare to MLP networks. This is because that localized neural network could offer conservative regression in RBF. Adding random disturbance in training dataset is helpful to reduce the influence of detector failure and uncertainty. Some convolution neural networks seem to be helpful to get more accurate results by use more spatial layout information, though relative researches are still under way.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.877-879
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• 1995

In this study, we developed the efficient brushless DC motor for a compressor of air conditioner. The characteristics of motor are under the control of the material of some parts and the shape of magnet. Especially we compared the interior shape to the surface shape of the magnet. And we optimized the parameters like the temperature and the materials of magnet and core by tool for more efficient motor.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.556-559
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• 2006

We successfully developed a high performance and highly reliable blazed GxL device with a high optical efficiency and a high contrast ratio. The device demonstrated superior resistance against a high power laser, which is suitable for a large-area laser projector. We operated the world's largest laser projection screen using this device at the 2005 World Exposition in Aichi, Japan, problem free.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1320-1323
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• 2002

This paper reviews the Korean government’s selection process of core wireless communications technologies, and presents technology trends, perspectives and strategies of 5 core technologies to develop in wireless communications areas based on the mid term IT technology development plan(2002∼2004). Delphi Panel Method and Analytic Hierarchy Process(AHP) Analysis were adapted to select 30 core technologies in 9 strategic areas. Especially, 5 core wireless communications technologies out of 24 required technologies are selected: 4 G Core Technology, Broadband Wireless Access Network Technology, IMT-2000 Plus STP Technology, OBP Based Multimedia Satellite Communications Technology, Stratosphere Communications System Technology. Strategic national IT R&D program has been essential to continue success story of CDMA technology, and acquiring technology independency from advanced nations. In long term perspectives, a strategy of intensive investment with prudent selection onto core technologies should be deployed in the IT R&D programs. Also, the national IT R&D programs should be limited in the high risk & high returen areas where only government can afford the failures as well as better spill over effects are expected for the technology development and national economy. Korean industry has some strength in wireless communications technology area. Therefore, more policy concerns should be given into this area not only to secure present strength but also to explore better technology competitiveness.

• Design & Manufacturing
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• 제13권2호
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• pp.17-21
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• 2019

In this study, selective laser sintered 3D printing mold core and metal core were used to investigate the difference of the thickness shrinkage from the gate of the injection molded part at a constant interval. SLS 3D printing mold core was made of nylon-based PA2200 powder and the metal core was manufactured by conventional machining method. As the PA2200 powder material has low strength, thermal conductivity and high specific heat characteristics compared with metal, molding conditions were set with the consideration of molten temperature and injection pressure. Crystalline resin(PP) and amorphous resin(PS) with low melting temperature and viscosity were selected for the injection molding experiment. Cooling time for processing condition was selected by checking the temperature change of the cores with a cavity temperature sensor. The cooling time of the 3D printing core was required a longer time than that of the metal core. The thickness shrinkage of the molded part compared to the core depth was measured from the gate by a constant interval. It was shown that the thickness shrinkage of the 3D printing core was 2.02 ~ 4.34% larger than that of metal core. In additions, in the case of metal core, thickness shrinkage was increased with distance from the gate, on the contrary, in the case of polymer core showed reversed aspect.

• 한국주조공학회지
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• 제33권4호
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• pp.147-156
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• 2013

The effects of core materials on the microstructure and mechanical properties of Al casting products have been investigated. The Al casting samples and cylinder head were fabricated by using organic and inorganic binder core respectively, and their microstructure and mechanical properties were evaluated. The Al casting samples fabricated by using inorganic core showed the better mechanical properties such as tensile strength and elongation than those of the Al casting samples fabricated by using organic core. That's because the Al casting samples contained small amount of pore defects and had fine microstructure compared with the Al casting samples fabricated by using organic core. Also, the use of inorganic core effectively reduced harmful gas emission and pollution.