• Nuclear Engineering and Technology
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• 제53권3호
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• pp.793-803
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• 2021

The small PWR has been paid more and more attention due to its diversity of application and flexibility in the site selection. However, the large core power density, the small containment space and the rapid accident progress characteristics make it difficult to control the containment pressure like the traditional PWR during the LOCA. The pressure suppression system has been used by the BWR since the early design, which is a suitable technique that can be applied to the small PWR. Since the configuration and operating conditions are different from the BWR, the pressure suppression system should be redesigned for the small PWR. Conducting the experiments on the scale down test facility is a good choice to reproduce the prototypical phenomena in the test facility, which is both economical and reasonable. A systematic scaling method referring to the H2TS method was proposed to determine the geometrical and thermohydraulic parameters of the pressure suppression containment response test facility for the small PWR conceptual design. The containment and the pressure suppression system related thermohydraulic phenomena were analyzed with top-down and bottom-up scaling methods. A set of the scaling criteria were obtained, through which the main parameters of the test facility can be determined.

• 대한한의학회지
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• 제38권3호
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• pp.1-12
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• 2017

Objectives: To interpret the meanings of Ryodoraku data and to use it as diagnosis tool, study on relationship between Ryodoraku and autonomic nervous reaction (ANR) has to be preceded prior to disease studies. This study aims to observe the change of Ryodoraku characteristics with ANR caused by treadmill exercise via a feasibility study. Methods: The electric current at 24 Ryodoraku points(H1~H6 at left/right wrists and F1~F6 at left/right feet) and vital signs were measured at rest, immediately after the treadmill exercise test, and at later recovery times(10min, 20min, 30min, 60min, 120min after the exercise test). The calculated Ryodoraku scores (RSs) were analyzed using repeated ANOVA test. Results: The RSs in the wrist Ryodoraku points were significantly increased immediately after the exercise (p<.05) and at 10min recovery time (p<.01), and no significant differences were found during the rest of the experimental sets. To the contrary, the RSs in the feet Ryodoraku points showed less difference throughout all the measurement time. Conclusions: The Ryodoraku characteristics change more sensitively in the wrists than in the feet in accordance with the previously reported sweat gland responses of the treadmill exercise. This is the first feasibility study to observe the change of Ryodoraku characteristics caused by treadmill exercise, and it shows the Ryodoraku characteristics are in accordance with known ANS responses.

• 한국주거학회:학술대회논문집
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• 한국주거학회 1998년도 International Housing Conference
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• pp.108-110
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• 1998

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1997년도 하계 학술대회 논문집
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• pp.170-176
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• 1997

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2005년도 춘계 학술발표회 논문집
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• pp.13-15
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• 2005

• 한국지진공학회논문집
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• 제15권1호
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• pp.29-38
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• 2011

이 연구에서는 평면, 입면 및 구조적 특성이 다양한 철근 콘크리트 고층 아파트 건물의 고유주기를 예측할 수 있는 새로운 식을 제안하였다. 제안식은 벽체의 진동이론과 지진시 계측된 건물들의 고유주기로부터 개발 되었으며, 평면에서 다양한 방향으로 설계된 전단벽의 구조적 특성을 적절히 반영할 수 있다. 제안식의 검증을 위해 신축 중인 국내 아파트 건물 10개동의 고유주기를 측정하였으며, 측정된 고유주기는 제안식 및 KBC 2009, ASCE 7-10과 같은 기준식들과 비교 하였다. 비교 결과, 제안식은 기준식에 비해 최근의 철근콘크리트 전단벽 건물 특성을 합리적으로 반영함으로써 고유주기를 보다 정확하게 예측하는 것으로 나타났다.

• 한국광학회지
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• 제6권4호
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• pp.345-351
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• 1995

유한한 폭을 갖는 배경에서 기본 어두운 공간솔리톤의 진행특성을 실험적으로 연구하여 전산시늉한 결과와 비교하였다. 실험적으로 빔의 세기가 증가함에 따라 어두운 솔리톤의 폭이 감소하고 배경의 폭은 증가함을 확인하였고 무한한 폭의 배경을 가정한 솔리톤 상수로부터 구한 굴절율의 변화량은 Z-스캔 방법으로 구한 굴절율의 변화량보다 작았다. 유한한 폭을 갖는 배경에 놓인 기본 어두운 솔리톤의 진행을 전산시늉하여 진행거리에 따른 배경의 첨두세기, 어두운 솔리톤의 폭 그리고 솔리톤 상수의 변화를 연구하였다. 유한한 크기의 배경에서 솔리톤상수의 변화를 고려하여 구한 굴절율의 변화량은 Z-스캔 방법으로 구한 굴절율의 변화량과 일치하였다.

• 한국기계가공학회지
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• 제8권3호
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• pp.68-73
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• 2009

This paper deals with the dynamic characteristics of the impeller shaft model which is the most important part in developing the resin mixing machine. The can is rotating by air motor in mixing machine. Then the end of shaft is fixed. The bearing support is to increase the fundamental natural frequency. The natural frequency analysis using finite element analysis software are performed on the imported commercial impeller shaft model. This paper presents calculated bearing stiffness of Soda, Harris and modified Harris formula considering contact angle according to bearing supported position. The most important fundamental natural frequency of the impeller shaft except bearing support is around 13.932 Hz. This paper presents one bearing and two bearings support position to maximize the 1st natural frequency. The maximized fundamental natural frequency is around 48.843 Hz in one bearing support and 55.52 Hz in two bearings support.

• Earthquakes and Structures
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• 제22권4호
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• pp.345-353
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• 2022

The configuration of an open ground floor (pilotis) is a common and very critical irregularity observed in multistory reinforced concrete frame structures. The characteristics and the geometrical formation of the beams of the first story proved to be a critical parameter for the overall seismic behavior of this type of Reinforced Concrete (RC) structures. In this work the combination of open ground floor (pilotis) morphology with very strong perimetrical beams at the level of the first story is studied. The observation of the seismic damages and the in situ measurements of the fundamental period of four buildings with this morphology and Π-shaped plan view are presented herein. Further analytical results of a pilotis type Π-shaped RC structure are also included in the study. From the measurements and the analytical results yield that the open ground floor configuration greatly influences the fundamental period whereas this morphology in combination with strong beams can lead to severe local shear damages in the columns of the ground floor. The structural damage was limited in the columns of the ground floor and yet based on the changes of the in situ measured fundamental period the damaged level is assessed as DI=88%. Furthermore, due to the Π-shape of the plan view the tendency of the parts of the building to move independently strongly influences the distribution of the damages over the ground floor vertical elements.

• 전기의세계
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• 제28권1호
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• pp.53-58
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• 1979

In the microwave heating system, a ferroresonant transformer is used to regulate the magnetron power fluctuation. For the simplification, nonlinear characteristics of the transformer and the magnetron are idealized to be piecewise linear. Dipped peak shape of the magnetron current is explained qualitatively by considering the fundamental and third harmonic frequency components in the circuit. Design equations providing the values of the leakage inductance, turn ratio of the transformer and the capacitance are derived analytically by cosnidering the fundamental frequency component only. The ferroresonant transformer is designed to obtain a required regulation and high input power factor from the derived design equations, and analytical calculations are compared with experimental measurements.