• 방송공학회논문지
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• 제23권5호
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• pp.606-613
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• 2018

본 연구는 대규모 영상처리를 위한 메모리 확장을 위한 외장 메모리 확장장치 구현에 관련된 내용으로, 이는 영상처리를 위한 그래픽 워크스테이션에 장착되는 PCI(Peripheral Component Interconnect) Express Gen3 x8 인터페이스를 가지는 외장 메모리 어댑터 카드와 외장 DDR(Dual Data Rate) 메모리로 구성된 외장 메모리 보드로 구성되며, 메모리 어댑터 카드와 외장 메모리 보드간의 연결은 광 인터페이스를 통하여 이루어진다. 외장 메모리 억세스를 위해서는 Programmable I/O 방식과 DMA(Direct Memory Access) 방식을 모두 사용할 수 있도록 하여 영상 데이터의 효율적 송수신이 이루어지도록 하였다. 본 연구 결과의 구현은 Altera Stratix V FPGA(Field Programmable Gate Array)와 40G 광 트랜시버가 장착된 보드를 사용하였으며, 1.6GB/s의 대역폭 성능을 보여주고 있다. 이는 4K UHD(Ultra High Definition) 영상 한 채널을 담당할 수 있는 규모이다. 향후 본 연구를 계속 진행하여 3GB/s 이상 대역폭을 보이는 연구결과를 보일 예정이다.

• 대한한의학원전학회지
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• 제28권4호
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• pp.65-77
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• 2015

Objectives : This literature study about dental external treatments from Hyangyakjibsungbang Tooth will invigorate applying the therapeutics in the field of Dentistry. Methods : In this study, the parts related to external treatment in the original text of Hyangyakjibsungbang Tooth were reviewed. Results : Examples of frequently used external method were gargling, applying powder, and brushing one's tooth. These methods are still used in modern dental treatment. Conclusions : Discovering new herbal medicines that provide better effects and developing more precise external treatments will advance dental treatment in Korean medicine.

• 한국과학교육학회지
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• 제28권5호
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• pp.471-481
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• 2008

이 연구에서는 학생들이 현재의 과학 교과서에서 화학 개념 학습을 위해 제시된 외적 표상들을 연계하는 과정에서 범하는 오류 유형을 학생들의 장독립성-장의존성에 따라 조사했다. 1개 중학교 1학년 학생 196명을 '보일의 법칙'을 학습하는 BL 집단과 '샤를의 법칙'을 학습하는 CL 집단으로 배치한 후, 장독립성-장의존성 검사를 실시했다. 각 집단 학생들에게 물질의 입자성이 강조된 글과 그림으로 해당 개념을 학습하게 한 후, 연계 과정 검사를 실시했다. 연구 결과, '불충한 연결', '부적절한 연결', '무분별한 연결', '불가능한 연결', '연결 불이행'의 5가지 연계 오류 유형이 나타났다. 이 중에서도 목표 개념과 관계없이 '연결 불이행', '부적절한 연결', '무분별한 연결'이 많이 나타났다. 장독립적 학생들과 장의존적 학생들이 범한 연계 오류의 빈도 사이에는 통계적으로 유의미한 차이가 없었다. 이에 대한 교육적 함의를 논의했다.

• Tribology and Lubricants
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• 제32권2호
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• pp.39-43
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• 2016

Magnetorheological elastomers (MREs) are a type of “smart” material, and their properties can be controlled rapidly and reversibly under the influence of an external stimulus. The application of an external magnetic field can change the shear modulus, hardness, and friction coefficient of MREs. The friction can cause vibration; moreover, the vibration can affect friction. The change of friction depends on the relative motion, normal force, roughness of the rubbing surfaces, material type, temperature, lubrication, relative humidity, and vibration condition. As MREs are a type of “smart material,” their friction coefficient can be reduced by applying an external magnetic field—the applications of this feature in engineering have been widely studied. However, the friction properties of MREs under vibration have not been tested to date. In this study, MRE samples and a reciprocating friction tester were fabricated. The friction coefficient was measured to evaluate the friction properties under various vibration conditions; subsequently, the wear depth and wear surface profile of the MRE were observed in order to evaluate the wear properties. The results show that the friction coefficient of the MREs decreased when a magnetic field was applied. Moreover, the friction coefficient decreased when the vibrational amplitudes increased. The wear depth of the MRE also decreased as the vibrational amplitudes increased.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.71-73
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• 2006

AC loss on variation of external magnetic field is a very important factor in development of power applications. In this paper, we measured and compared AC loss of hybrid-multi stacked wire made of the combination of 1G wires and 2G wires and uniform-multi-stacked wire made of one type of wires, 1G wires or 2G wires. Measurement was performed using by the linked-picked coil method. As results, as the number of wires increase, AC loss per unit volume of both stacked wires in low external magnetic field is reduced. Also AC loss of 2G slacked wire is higher than that of 1G wire. AC loss per unit length of 2G stacked wire is less than that of 1G stacked wire. And AC loss of hybrid-multi stacked wire made of the combination of 1G wires and 2G wires was between uniform-multi-stacked wire made of 1G wires and 2G wires.

• 한국해양공학회지
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• 제22권3호
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• pp.18-23
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• 2008

This study investigated interactions between the internal-external wave field of a permeable coastal structure consisting of rubble. The study examined the application criteria of an existing numerical model (CADMAS-SURF V.4.0) and proposed a modified method to provide reasonable results. In particular, the study focused on and emphasized the water surface profiles in front of a structure, wave run-up/run-down on a slope, and internal water level fluctuations due to the drag coefficient and porosity of a rubble mound structure. In conclusion, the result show that when the vertical fluctuations of the internal water levels in permeable coastal structures exhibited high-quality representation. Sane responses can be seen for wave run-up/run-down characteristics on its slopes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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• pp.105-108
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• 2002

In this paper, we investigated the fault current limiting characteristic of flux-lock type High-Tc superconducting fault current limiter(HTSC-FCL), which is comprised of a flux-lock reactor and an external magnetic field coil covering the HTSC element In this HTSC-FCL, the initial limiting current level can be controlled by adjusting the inductance of the each coil. Furthermore, the fault current limiting characteristics of HTSC-FCL can be improved by applying 'the external magnetic field into the HTSC element We performed the computer simulation by numerical analysis about the flux-lock type HTSC-FCL and compared the results of experiment with simulation ones. We can obtain the same results from both the computer simulation and the experiment except for the time immediately after fault occurs.

• 한국안전학회지
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• 제16권4호
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• pp.123-127
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• 2001

Numerous PSC bridges are stregthened by the combined use of continuity of simple spans and addition of external prestressing. In this case prestressing sequences should be carefully checked due to the effect on the stress and camber of girders and slab. Various prestressing sequences were applied in this field test and measured values were analysed. This results show that preatressing sequences affact the stress and deflection of bridge members, so the prestressing sequence should be considered at the desist and construction stages of deteriorated bridges.

• 한국철도학회논문집
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• 제9권2호
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• pp.160-168
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• 2006

The major objective of this study is to investigate the effects and application of external post-tensioning method far steel plate girder bridge. It analyzed the mechanical behaviors of steel plate girder bridge with applying external post-tensioning on the finite element analysis, field test and laboratory test fur the lateral dynamic characteristics. As a result, the reinforcement of steel plate girder bridge the external post-tensioning method are obviously effective for the lateral dynamic response which is non-reinforced. The analytical and experimental study are carried out to investigate the post-tension force decrease lateral acceleration and deflection on steel plate girder bridge for serviceability. And the external post-tensioning method reduce dynamic maximum displacement(about $10{\sim}24%$), the increase of dynamic safety is predicted by adopting external post-tensioning method. From the dynamic test results of the servicing steel plate girder bridge, it is investigated that the change degree of natural frequency is very low with applying the external post-tensioning method The servicing steel plate girder bridge with external post-tensioning has need of the reasonable reinforcement measures which could be reducing the effect of lateral dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

• 한방안이비인후피부과학회지
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• 제30권3호
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• pp.155-165
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• 2017

Objectives : The purpose of this study is to analyze the trends of domestic experimental research of external treatment in Korean medicine and use it as a basic data to expand the therapeutic field of Korean medicine. Methods : In December 2016, two authors searched for experimental studies of external treatment in Korean medicine researches in 6 Korean databases. Results : Among the 379 researches that were initially searched, two authors reviewed 190 researches, excluding duplicate researches, and finally 11 researches were selected for the study. The target disease was confined to the skin and mucosa, and the most of selected Korean medicine was based on the literature. Conclusions : Considering the range of application of the external treatment described in the literature and the domestic market for external medicine, it is expected that the development of various external medicine using herbal medicine will be expected in the future.