• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2008년도 Asian Magnetics Conference
• /
• pp.178-178
• /
• 2008

This paper presents an efficient approach for simulating the loss of the laminated core joints in power transformers. Two laminated core models, with the same material and joint type but different leg length, are established for validating the specific total loss inside the joint region.

• 기술혁신연구
• /
• 제15권2호
• /
• pp.123-152
• /
• 2007

The striking characteristic of the contemporary global security environment is that the nature of threats has become diverse and complex. For example, transnational and non-military threats including terrorism and proliferation of weapon of mass destruction has increased. In this security environment, Advanced countries funnel their investments for defense budgets into the assurance of key force capability and R&D of cutting-edge core technologies, in consideration of future battlefield environments so as to get an edge on not only defense science and technology but also intelligence capabilities. As shown by past practices of the korea's defense acquisition, the ministry of national defense has tried to enhance its force capabilities in the short-term by purchasing foreign weapon systems rather than by investing in domestic R&D. Accordingly, the technological gaps between the korea and advanced countries were widened due to both insufficient investment in development of domestic technologies and avoidance of technological transfer by advanced countries. Thus, for the effective execution of the R&D budget and the successful performance of the projects, the importance of selection, management and evaluation of the R&D projects is emphasized. So, The objective of this study is that the analysis of the proposal-selection evaluation system for the realization of the successful defense core technology R&D projects. This study focused on the improvement of the proposal-selection evaluation model which can be applicable to the national defense core R&D projects. Using the improved proposal-selection evaluation system, we propose a model to enhance the reliability of the national defense core technology R&D project evaluation system.

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

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.1183-1184
• /
• 2006

Core loss of soft magnetic powder cores have been focused on to achieve high efficiency of power supplies. In this study the effects of crystal grain size on core loss were investigated by changing heat treatment conditions. It was found that core loss is influenced by crystal grain size because eddy current loss decreased and hysteresis loss increased by making crystal grain size smaller, and it is also influenced by particle size.

• 한국산학기술학회논문지
• /
• 제20권9호
• /
• pp.351-361
• /
• 2019

본 연구는 동료평가를 활용한 핵심기본간호술의 실습교육평가방법이 졸업반 간호학생의 핵심기본간호술 수행능력, 학습태도, 비판적사고 및 셀프리더십에 미치는 효과를 파악하고자 하였다. 연구대상자는 핵심기본간호술 교과목 수강자 4학년 학생으로 총 326명이었으며, 자료수집은 2018년 한 학기동안 실시하였다. 자료는 AMOS 20.0과 SAS 9.3 프로그램을 이용하였으며 t-test, ANOVA, Pearson correlation coefficient, Scheffe test로 분석하였다. 연구결과로, 동료평가를 활용한 핵심기본간호술 수행능력의 평균평점은 3.77(${\pm}.62$)점, 학습태도 3.17(${\pm}.47$)점, 비판적 사고는 3.44(${\pm}.41$)점, 셀프리더십은 3.60(${\pm}.49$)점으로 나타났다. 핵심기본간호술 수행능력은 성별, 간호학 전공만족도, 핵심기본간호술 실습만족도, 동료평가 전 사전학습여부, 동료평가 만족도에 따라 유의한 차이를 나타냈다. 핵심기본간호술 수행능력은 학습태도(r=.295, p<.001)와, 비판적사고는 핵심기본간호술 수행능력(r=.384, p<.001), 학습태도(r=.623, p<.001)와, 셀프리더십은 핵심기본간호술 수행능력(r=.353, p<.001), 학습태도(r=.529, p<.001), 비판적사고(r=.690, p<.001)와 유의한 순상관 관계를 나타냈다. 핵심기본간호술 수행능력에 영향을 미치는 요인은 구조방정식 모형을 적용하였으며 비판적사고, 셀프리더십으로 나타났다. 따라서 이러한 연구결과를 바탕으로 핵심기본간호술 수행능력 향상을 위해 학습태도, 비판적사고 및 셀프리더십을 고려한 핵심기본간호술 실습교육프로그램 개발이 필요할 것이다.

• Design & Manufacturing
• /
• 제2권3호
• /
• pp.16-21
• /
• 2008

In recent, the demands of household cases and disposable products is increased significantly because a living standard of newly-emerging nations was risen. Therefore, multi-cavity mold and stack mold for the realization of high-productivity have been researched in forefront nations. In this paper, CAE analysis for minimizing the mold core deformation was performed. Finally, 64 cavities injection mold for molding cap which has the insert-type core was fabricated according to the result of CAE analysis.

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

• 정보관리학회지
• /
• 제15권2호
• /
• pp.137-162
• /
• 1998

본 연구의 목적은 디지털 도서관 환경에서 도서, 비도서자료 및 인터넷자원을 포괄적으로 기술할 수 있는 서지레코드 핵심데이터요소를 제시하는데 있다. 이를 우해 현대 편목규칙의 기반이 되는 AACR2R의 기술사항, 목록의 비용효과를 효율적으로 거둘수 있는 미국국회도서관의 핵심레코드(Core Record), 인터넷자원을 기술하기 위해 제안된 더블린코어(Dublin Core) 메타데이터, KORMARC 등의 데이터요소를 비교분석하였다. 비교결과를 토대로 핵심데이터요소를 필수요소, 적용 가능한 경우에 필수요소, 선택요소로 구분하여 제안하였다.

• 공업화학
• /
• 제7권4호
• /
• pp.809-812
• /
• 1996

일반화된 van der Waals류의 3차 상태방정식에 사용되는 인력 및 반발력 상수항을 온도의존 함수로 나타내는 core-softening 이론을 도입하여 van der Waals 유체의 비이상적 열팽창, 즉 밀도 비이상성을 설명하였다. 온도의존 함수로는 온도의 증가에 따라 hard-core의 직경피 줄어드는 $db_r/dT_r<0$을 만족하는 형태와, 분자간의 반발력이 강해지는 $da_r/dT_r>0$을 만족하는 식을 사용하였다. 온도에 따른 밀도 최대점은 전자의 경우 전 범위의 압력하에서 나타났으며 후자의 경우 유체에 장력(tension)이 가해질때만 존재하였다.

• ETRI Journal
• /
• 제25권5호
• /
• pp.337-344
• /
• 2003

In this paper, we introduce a fully synthesizable 32-bit embedded microprocessor core called the AE32000B. The AE32000B core is based on the extendable instruction set computer architecture, so it has high code density and a low memory access rate. In order to improve the performance of the core, we developed and adopted various design options, including the load extension register instruction (LERI) folding unit, a high performance multiply and accumulate (MAC) unit, various DSP units, and an efficient coprocessor interface. The instructions per cycle count of the Dhrystone 2.1 benchmark for the designed core is about 0.86. We verified the synthesizability and the area and time performances of our design using two CMOS standard cell libraries: a 0.35-${\mu}m$ library and a 0.18-${\mu}m$ library. With the 0.35-${\mu}m$ library, the core can be synthesized with about 47,000 gates and operate at 70 MHz or higher, while it can be synthesized with about 53,000 gates and operate at 120 MHz or higher with the 0.18-${\mu}m$ library.