• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2979-2986
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• 2011

In this study, we review all matters for system application based on the international and the domestic standards. Considering the minimization of bottom frame damage, ease of maintenance, withstanding-environmental performance (condensation or rain), maintenance of airtightness, customer convenience and safety issues in railway vehicle, the conceptual design for doorstep equipment for both the low and the high level platforms is carried out. On the basis of conceptual design, the prototype is manufactured. We perform the vibration test based on the international standard IEC-61373 for securement of the reliability and enhancement of design & production. Finally we would like to describe the test results.

• 중국학논총
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• 제69호
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• pp.121-143
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• 2021

'老' refers to the old man with the characteristics of being aged in the original meaning 'to be aged' (adjective), which is a metonymy of 'substituting the whole with a part'. In combination with nouns, '老' uses a lot of metaphorical expressions that are understood through animals closest to the attributes of people with aged characteristics, plants and objects. '老' can be extended to the meaning of 'the survival time, duration, recognition time, and existence time of a person, animal, plant, or object are long', or 'the survival time is over', which can be said to be a metonymy of 'substituting cause with result'. An experienced target respected by people on a positive level and a target with banal thoughts, habits, nature, and personality on the negative level can also be conceptualized and expressed as '老'.

• 한국안전학회지
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• 제34권3호
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• pp.102-110
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• 2019

This paper describes the work and results of the preliminary Probabilistic Safety Assessment (PSA) for a research reactor in the design phase. This preliminary PSA was undertaken to assess the level of safety for the design of a research reactor and to evaluate whether it is probabilistically safe to operate and reliable to use. The scope of the PSA described here is a Level 1 PSA which addresses the risks associated with core damage. After reviewing the documents and its conceptual design, eight typical initiating events are selected regarding internal events during the normal operation of the reactor. Simple fault tree models for the PSA are developed instead of the detailed model at this conceptual design stage. A total of 32 core damage accident sequences for an internal event analysis were identified and quantified using the AIMS-PSA. LOCA-I has a dominant contribution to the total CDF by a single initiating event. The CDF from the internal events of a research reactor is estimated to be 7.38E-07/year. The CDF for the representative initiating events is less than 1.0E-6/year even though conservative assumptions are used in reliability data. The conceptual design of the research reactor is designed to be sufficiently safe from the viewpoint of safety.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(1)
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• pp.289-294
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• 1996

Feasibility study on conceptual design tool for liquid metal reactor has been conducted to optimize the thermohydraulic and neutronic design parameters. To accomplish this task the neutronic code PRISM, fuel performance code and scaling method have been included into the conceptual design support system. ALMR(PRISM 303MWe) has been adopted as the reference plant and principally according to the power level, conceptual design parameters are optimized so that energy balance and neutronics balance seem to be satisfied. This paper presents only the results of optimization on primary system including the IHX system.

• Journal of Astronomy and Space Sciences
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• 제23권4호
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• pp.445-452
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• 2006

이 논문은 OBC와 위성 서브 컴포넌트와 같은 원격장비 사이의 데이터 접속을 근간으로 하는 위성 디지털 베이스 밴드의 개념설계를 기술한다. 본 개념설계에서는 OBC와 위성 원격장비 사이의 데이터 접속을 단일화하고 그 접속 단계를 계층화한 결과를 제시한다. 다른 형태의 시스템과의 비교를 수행하였으며, 이 개념에 의한 디지털 베이스 밴드의 장단점을 고찰하였다.

• International Journal of Aeronautical and Space Sciences
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• 제6권1호
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• pp.89-96
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• 2005

Ducted fans have advantages in noise as well as operational safety aspects compared to conventional tail rotors and are used as an anti-torque system for various classes of helicopters. The final goal of this study is to develop a ducted fan anti-torque system which can replace conventional tail rotors of existing helicopters to achieve safety enhancement and low noise level. In this paper, a conceptual design process and the results are described. Initially, the design requirement and the design parameter characteristics are analysed, and then initial sizing and configuration design are performed. There are several configuration changes due to specific technical reasons in each case. Finally, the required power and the pitch link load are predicted as an initial estimation. The conceptual design technique for the ducted fan in this study can be easily applied to the design of other ducted fans such as the lift fan for unmanned aerial vehicle.

• 한국초등과학교육학회지:초등과학교육
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• 제32권1호
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• pp.71-81
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• 2013

This study aimed to investigate the changes in learner's scientific conceptual formation and academic achievement after a CoRe-based science lesson. For this study, two classes of the 6th grade of elementary school were divided into an experimental class and a comparison one. The students of the experimental class received CoRe-based science lesson and those of the comparison one received general science lesson. Both of the classes studied 'unit 1. A change in the weather', which is a part of content of 6th grade science text book. The results of this study were as follows. First, in the questions of invisible and abstract phenomena, students had misconceptions based on their experience in real life, or did not understand the fundamental causes of that phenomena. But after receiving lessons respectively, experimental class generally showed at a higher rate of understanding the causes of the phenomena than comparison class. Second, CoRe-based science lesson was more effective to improve students' scientific conceptual formation than the general science lesson. Moreover, when two classes were respectively divided into two groups as high and low-level groups according to their pre-test achievement records, the CoRe-based science lesson was more effective to learners of the high-level groups. Third, CoRe-based science lesson was more effective to enhance students' academic achievements than the general science lesson, especially to learners of the low-level groups.

• 컴퓨터교육학회논문지
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• 제9권2호
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• pp.79-88
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• 2006

본 연구에서는 개념 학습에서 학생들의 개념 이해 수준에 적응적인 CAI의 효과를 개념 이해도, 개념 파지, 학습 동기, 컴퓨터 보조 수업에 대한 인식 측면에서 조사하였다. 서울시의 한 남녀 공학중학교 1학년 94명의 학생들을 통제 집단, CAI 집단 적응적 CAI 집단에 임의로 배치하고, 7차시 동안 '분자의 운동'에 대하여 수업을 실시하였다. 이원 공변량 분석 결과 적응적 CAI 집단의 개념검사 점수 및 학습 동기 검사 점수가 통제 집단의 점수들에 비하여 유의미하게 높았다. 개념 파지검사에서는 적응적 CAI 집단의 점수가 다른 두 집단의 점수에 비하여 유의미하게 높았다. 개념 이해도, 개념 파지, 학습 동기 검사에서 수업 처치와 사전 성취 수준 사이의 상호작용 효과는 없었다. 컴퓨터 보조 수업에 대한 인식에서는 적응적 CAI 집단의 학생들이 CAI 집단의 학생들보다 긍정적인 것으로 나타났다.

• 한국초등과학교육학회지:초등과학교육
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• 제25권1호
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• pp.39-50
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• 2006

The purpose of this study was to investigate the effect of metacognitive strategy on conceptual acquisition ofvseasonal change and self-efficacy when it was applied to 6th grade elementary students. This study consists of 2 classes, 76 students in the 6th grade of elementary school, which were divided into the experimental group (38) and the control group (38). First, a pre-test was administrated to check students' levels of metacognitive self-regulation and self-efficacy prior to getting planned lessons and then an instruction program was developed based upon the metacognitive instruction model and students' conception. The control group was exposed to traditional methods mainly using the textbook and teacher's guide book. The experimental group employed a metacognitive learning strategy program and activities with metacognitive questionnaires. After the planned lessons, the students were tested with post-tests about the conception of seasonal change and self-efficacy. One month later the students were tested again with another test to determine the continuation effect. The results were as follows: First, the group that used metacognitive conceptual change instruction did better in forming and continuing to maintain the scientific seasonal change conceptions compared to the control group. Second, the high and intermediate group taught by metacognitive conceptual change instruction was higher in the level of self-regulation than the control group. However, it was not verified in the low group. Third, the group which used metacognitive conceptual change instruction showed a higher level of self-efficacy than the control group did.

• 대기
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• 제20권2호
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• pp.131-151
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• 2010

This study establishes a conceptual model to analyze heavy rainfall events in Korea using multi-functional transport satellite-1R satellite images. Three heavy rainfall episodes in two major synoptic types, such as synoptic low (SL) type and synoptic flow convergence (SC) type, are analyzed through a conceptual model procedure which proceeds on two steps: 1) conveyer belt model analysis to detect convective area, and 2) cloud top temperature analysis from black body temperature (TBB) data to distinguish convective cloud from stratiform cloud, and eventually estimate heavy rainfall area and intensity. Major synoptic patterns causing heavy rainfall are Changma, synoptic low approach, upper level low in the SL type, and upper level low, indirect effect of typhoon, convergence of tropical air in the SC type. The relationship between rainfall and TBBs in overall well resolved areas of heavy rainfall. The SC type tended to underestimate the intensity of heavy rainfall, but the analysis with the use of water vapor channel has improved the performance. The conceptual model improved a concrete utilization of images and data of satellite, as summarizing characteristics of major synoptic type causing heavy rainfall and composing an algorism to assess the area and intensity of heavy rainfall. The further assessment with various cases is required for the operational use.