• Title/Summary/Keyword: co-ideal

검색결과 304건 처리시간 0.024초

FIELD DATA를 이용한 진동시험 규격화 방안 (Packaging Vibration Specification Based on Field Data)

  • 김응주;이수근
    • 한국포장학회지
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    • 제4권2호
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    • pp.39-44
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    • 1998
  • We used recording device(EDR-3) to monitor the packages and the vehicle during shipment. Provided we did this enough times, we began to gain statistically valid information which could be used to describe the particular channel of distribution. The event was obviously changed from trip to trip, but in general we could have an idea of what to expect. Considerable amount of time and money were invested to record field data. Although not ideal, it was the best suited approach to gain information regarding a specific distribution channel. Based on the recorded field data, we could make our own packaging vibration testing specification through MIL-STD-810D(Guidance for development of laboratory dynamic test specification). This test specification was proved several times through field tests. As a result, we gained confidence in this revised vibration specification and come to know the development procedures of a laboratory dynamic test specification.

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물리적인 전력소자 모텔을 이용한 대용량 인버터 시뮬레이션 기술 (High Power Circuit Analysis with the Simulation Technique using Physical Models of Power Devices)

  • 윤재학
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2002년도 전력전자학술대회 논문집
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    • pp.330-333
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    • 2002
  • The design of high power electronic circuits and the verification of the design by practical experiments are time and cost consuming. Recently power circuit simulation technique is developing to do it easily. However, most of the simulation has used the ideal switch model consists of passive component that can not describe the physical characteristics of semiconductor devices and cannot describe the switching transient state. For the design of such power electronic circuits by the simulation, the switching transients are very important. Therefore the simulation models must describe the switching transient and the stationary behavior as precisely as possible on the hand and as fast as possible the other hand. This paper introduces the application of the physical models of power devices that are developed by TUM(Technical University of Munich, Germany) for the power electronic circuit analysis.

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A Parallel Collaborative Sphere Decoder for a MIMO Communication System

  • Koo, Jihun;Kim, Soo-Yong;Kim, Jaeseok
    • Journal of Communications and Networks
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    • 제16권6호
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    • pp.620-626
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    • 2014
  • In this paper, we propose a parallel collaborative sphere decoder with a scalable architecture promising quasi-maximum likelyhood performance with a relatively small amount of computational resources. This design offers a hardware-friendly algorithm using a modified node operation through fixing the variable complexity of the critical path caused by the sequential nature of the conventional sphere decoder (SD). It also reduces the computational complexity compared to the fixed-complexity sphere decoder (FSD) algorithm by tree pruning using collaboratively operated node operators. A Monte Carlo simulation shows that our proposed design can be implemented using only half the parallel operators compared to the approach using an ideal fully parallel scheme such as FSD, with only about a 7% increase of the normalized decoding time for MIMO dimensions of $16{\times}16$ with 16-QAM modulation.

Hydrographic Model Test on Prevention against Vortex Occurrence for Vertical Bulb Turbine

  • Yamato, Shoichi;Nakamura, Shogo;Furukawa, Akinori
    • International Journal of Fluid Machinery and Systems
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    • 제2권4호
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    • pp.418-425
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    • 2009
  • A vertical bulb turbine unit with elbow type draft tube has been developed due to avoidance of complicated assembling and long standstill period at overhaul in comparison with conventional horizontal bulb turbine unit. Before designing the prototype vertical bulb unit, a hydrographic model test was carried out to establish the ideal design concept for this innovative generating unit. Froude similarity is not available for vortex occurrence. Consequently, an intake structure without air entraining vortices under all the flow conditions is developed, and it is confirmed that the surge wave at load rejection is not affected harmful influence for other constructions.

고지의무(告知義務)와 진단과실(診斷過失) (Duty of Representation & Negligence of Medical Examination)

  • 윤병학
    • 보험의학회지
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    • 제3권1호
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    • pp.55-61
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    • 1986
  • In life insurance the goal of medical examination is to exclude medical, environmental adverse-selection to the utmost. And keeping the principle of equity and the homogeneity of risk in the group of the insured, you are able to manage the company reasonably and realize the orginal ideal of life insurance, namely, the mutual assistance. And yet, the cases of the misrepresentation have been occurred frequently so far. As a result of them, the development of life insurance industry has been obstructed, and public criticism has been caused. Carrying medical examination, you have to know how the representation is important, And citing what the misrepresentation and false representation influenced the results, I want you to refer to medical exam-business.

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한국과 영국의 학교 성교육 비교연구 (School Sex Education in Korea and the U.K.)

  • 김정옥
    • 한국가정과교육학회지
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    • 제8권2호
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    • pp.1-14
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    • 1996
  • Sex education in the U.K. follows an ideal model, co-operation where ever possible between homes, schools, and communities, whereas in Korea schools are mostly responsible for sex education. Moreover, Central Government and LEAs are deeply involved in school sex education in the U.K., in contrast, the concrete help at Government level is very limited in Korea though the necessity of sex education is acknowledged. These differences be accounted for by the different social and cultural backgrounds of the two countries, especially given the different thoughts of the people-oriental and occidental-. In the U.K., sex education has been a compulsory subject in secondary schools since 1994 (by the Education Act 1993), and it is well managed with the support at Government level as compared with that of Korea. Sex education in the U.K. may give some lessons for practising and developing sex education in Korea because the people in both countries have similarly conservative thinking about school sex education and it is implemented very carefully in the U.K.. In this article, a general comparison of background, policy, aims, content, management, teacher training, and materials of sex education between the two countries is made.

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DEVELOPMENT OF A COMPUTER PROGRAM TO SUPPORT AN EFFICIENT NON-REGRESSION TEST OF A THERMAL-HYDRAULIC SYSTEM CODE

  • Lee, Jun Yeob;Suh, Jaeseung;Kim, Kyung Doo;Jeong, Jae Jun
    • Nuclear Engineering and Technology
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    • 제46권5호
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    • pp.719-724
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    • 2014
  • During the development process of a thermal-hydraulic system code, a non-regression test (NRT) must be performed repeatedly in order to prevent software regression. The NRT process, however, is time-consuming and labor-intensive. Thus, automation of this process is an ideal solution. In this study, we have developed a program to support an efficient NRT for the SPACE code and demonstrated its usability. This results in a high degree of efficiency for code development. The program was developed using the Visual Basic for Applications and designed so that it can be easily customized for the NRT of other computer codes.

Heteroepitxial p-n 접합을 위한 합리적 물질 설계

  • 이상훈;이태일;황성환;황성환;명재민
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2012년도 춘계학술발표대회
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    • pp.86.2-86.2
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    • 2012
  • 산화금속은 높은 결정성, quantum size effect, 높은 투과도, 대기중의 안정도 등과 같은 탁월한 성질들로 인하여 오늘날 실리콘의 대체물로서 많은 연구가 보고되고 있다. 이러한 금속산화물의 크기와 모양을 조절하며 대량 생산하기 위한 합성방법으로 가수분해, 금속양이온 응축법과 같은 다양한 수용액상 방법이 연구되고 있다. 하지만 2차원 단일 층에 나노물질을 정렬하고 전기적 접합을 형성하는 것이 매우 어렵다는 점 때문에 나노물질을 기판 위에 자유롭게 성장시키는 방법에 대해서는 아직 많이 보고 되어있지 않다. 본 연구에서 저온의 수용액에서 1차원의 나노막대가 2차원의 스피넬 구조 위에 heteroepotaxial 접합을 이루며 성장시키는 방법을 이용하였다. P-n접합 형성을 위하여 (0001)방향으로 배향된 n-type ZnO 나노막대를 (111)방향의 p-type Co3O4 나노플레이트 위에 성장시킨 구조를 제작하였으며 이를 바탕으로 다이오드소자를 제작하여 ideal factor, turn-on voltage, rectifying ratio등의 전기적 특성을 평가하였다.

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냉동기 펌프다운 운전성능에 관한 연구 (A Study on Pump Down Operation Performance of Refrigerator)

  • 김철수;정한식;정효민
    • 설비공학논문집
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    • 제18권12호
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    • pp.964-970
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    • 2006
  • Vapor compression refrigerators have much critical variables such as the controls of temperature and pressure switches, control durations and operating hours of electronic valves. This study compares and analyzes the data which is obtained from system controlling of the evaporation temperatures which are generally used in automatic pump down operating systems. Through this study, the automatic evaporation control operation system will be more ideal for the system to keep the proper temperature distribution depending on the purpose of evaporation side. The automatic pump down control operation is more appropriate for the system to aim at the effective use of evaporation side without using the temperature difference. And this test will be proved that the changes at the low pressure side didn't have significant impacts on the high pressure side.

Achievable Ergodic Capacity of a MIMO System with a MMSE Receiver

  • Kim, Jae Hong;Kim, Nam Shik;Song, Bong Seop
    • Journal of electromagnetic engineering and science
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    • 제14권4호
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    • pp.349-352
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    • 2014
  • This paper considers the multiple-input multiple-output (MIMO) system with linear minimum mean square error (MMSE) detection under ideal fast fading. For $N_t$ transmit and $N_r({\geq}N_t)$ receive antennas, we derive the achievable ergodic capacity of MMSE detection exactly. When MMSE detection is considered in a receiver, we introduce a different approach that gives the approximation of a MIMO channel capacity at high signal-to-noise ratio (SNR). The difference between the channel capacity and the achievable capacity of MMSE detection converges to some constant that depends only on the number of antennas. We validate the analytical results by comparing them with Monte Carlo simulated results.