• Title/Summary/Keyword: 글로브

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Structural Integrity Evaluation of Nuclear Seismic Category IIA 2" Globe Valve for Seismic Loads (지진하중을 받는 원자력 내진등급 2A 글로브 밸브의 구조 건전성 평가)

  • Chung, Chul-Sup
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1500-1505
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    • 2008
  • To evaluate the structural integrity of the nuclear seismic category IIA bellows seal 2" globe valve under the seismic service conditions the seismic analysis was performed in accordance with ASME, section III, ND-3500, 1989 edition. The finite element computer program, ANSYS, Version 10.0, is used to perform both a mode frequency analysis and an equivalent static seismic analysis of the valve assembly. The mode frequency analysis results show the fundamental natural frequency is greater than 33 Hz and does not exist in seismic range, thus justifying the use of the static analysis. The stresses resulted from various loadings and their combinations are within the allowable limits specified in the above mentioned ASME code. The results of the seismic evaluation fully satisfied the structural acceptance criteria of the ASME code. Accordingly the structural integrity on the globe valve was proved.

A Case Study of Root Cause Analyses and Remedies for High frequency Vibration of Globe Valve in Nuclear Power Plant Piping System (원자력 발전소 배관계 글로브 밸브의 고주파 진동 원인 분석 및 해결 사례)

  • Choi, Byoung-Hwa;Park, Soo-Il;Cheon, Chang-Bin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.394-399
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    • 2005
  • A case history is presented pertaining to high frequency piping vibration and noise caused by globe valve in the spent fuel pool cooling system of nuclear power plant. Frequency analyses were performed on the system to diagnose the problem and develop a solution to reduce the piping vibration and noise. The source of the high frequency and noise energy was traced to the globe valve located immediately downstream of the centrifugal pump by performing valve throttling test. Measurements of vibration and noise are presented to show that the high frequency vibration and noise amplitude was dependent upon the valve disc position and flow rate. Strouhal vortex shedding frequencies were generated at the exit of the globe valve which exited structural resonance of valve disc and amplified the high frequency vibration and noise. The problem was identified as an interaction between the flow inside globe valve and the valve disc structure. Attempts to reduce the vibration and noise amplitudes of the piping system were successfully achieved by the modification of guide-disc diameter and disc-edge figure The valve disc was replaced by an alternative to eliminate the source of the harmful high frequency vibration and noise.

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The Fermentation Characteristics and Sensory Properties of White Wine Using Imported Chilean Grape (수입 포도를 이용한 백포도주의 발효 특성과 관능적 특성)

  • Kim, Dong-Ho;Kang, Byung-Sun
    • Food Science and Preservation
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    • v.15 no.1
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    • pp.150-154
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    • 2008
  • This study investigated 1he fermentation characteristics and sensory properties of white wine made from the Chilean grape varieties Thomson Seedless (T), Red Globe (R), and a mixture thereof (M). The pH fell during fermentation and final pH values of 3.63-3.68 were slightly higher than is usual in white wine. The total acidity increased during the alcoholic fermentation and leveled at 0.56-0.71% Ater 15d, the sugar contents and specific gravities attained final values. The L value of wine made from R grapes increased from 65.05 to 96.77, of wine made from T grapes from 77.41 to 99.6, and of wine made from M grapes from 71.73 to 98.41. The a value of all wines decreased quickly during the first 4 d of fermentation and the b values of T and M wines (not R wine) also fell rapidly during this time. The final alcohol concentrations of the wines were 14 -14.9% (v/v). The white wines made from T, R, and M grapes received similar scores in a directional difference sensory test. The color and flavor of white wine made from T grapes scored highest (5.6 and 5.35 respectively; p<0.05 for both values), but overall acceptabilities of all three wines were similar (4.30-4.85, p<0.05).

A Study of Lens Design for LED Warning Light (LED 경광등 글로브 렌즈 설계에 관한 연구)

  • Shin, Kyung-Ho;Lim, Sung-Moo;Yeo, In-Seon
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1912-1914
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    • 2004
  • As the characteristics of LED disposition, LED warning light must be designed differently from general incandescent lamp warning light whose light source is located in origin. In this paper, the globe's lens of LED warning light was designed considering the LED intensity distribution and the arrangement of the LED. And prove the appropriateness of that design by simulation in LightTools which is optical design program.

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Electrical and Optical Characteristics of Fluorescent Luminaires for Naval Vessels (함정용 형광등기구의 전기.광학적 특성)

  • Cho, Hyang-Eun;Kim, Il-Kwon;Kim, Yoon-Sik;Kil, Gyung-Suk;Cho, Kyu-Lyong
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2011.06a
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    • pp.184-184
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    • 2011
  • 함정용 형광등기구는 설치되는 위치에 따라 매입형, 노출형, 램프 수에 따라 2등용과 3등용, 글로브형태에 따라 투명, 반투명으로 분류된다. 본 논문은 기존의 형광등기구를 LED로 교체하기 위한 기초 실험으로 이들 등 기구의 소비전력, 총광속, 색온도 및 빔각 등 전기 광학적 특성을 분석하였다.

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아름다운삶 - 건강열전 - 게임이론으로 경제학의 지평을 열다 - (존내시)

  • Park, Jun-Ho
    • 건강소식
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    • v.33 no.12
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    • pp.16-17
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    • 2009
  • 지난 2002년 골든글로브시상식에서 배우 러셀 크로우에게 남우주연상의 영예를 안겨준 영화 '뷰티풀 마인드'는 존 내시라는 천재 수학자의 일생을 담은 전기영화다. 존 내시는 실제로 21세 때 쓴 논문으로 40여년 후에 노벨상을 받을 정도로 뛰어나 천재였지만, 오만하고 괴팍하며 비사교적인 성격 덕택에 변변한 친구하나 없었다고 한다. 한때 오랜 기간 정신분열증을 알았던 그는 '숫자를 다루는 일에는 신이 부럽지 않을 만큼 능수능란했지만, 인간관계 함수를 파악하는 데는 갓난아기처럼 서툴렀던 사나이'였다.

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The Development Of Multi-Purposal Control Apparatus & High-Brightness LED Full Color Lamp Module (고휘도 LED를 이용한 다목적 풀컬러 램프모듈 및 제어장치 개발)

  • Youn, Soun-Jin;HwangBo, Soung;Eo, Ik-Su;Lee, Bae-Gyu
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.270-271
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    • 2007
  • LED를 이용한 램프개발 다목적 램프, 실내 조명용이나 전광판의 디스플레이용, 간판의 채널래터용으로 이용가능, LED 램프의 효율을 향상을 위해 반사판 설계, 3차원 설계로 반사판 설계 후 포토피아로 시뮬레이션 반사판과 글로브 형태 및 재질에 따른 광효율시뮬레이션

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Comparison of Loss Coefficient using 1-inch Ball and Glove Valve Opening Ratio (1인치 볼 밸브 및 글로브 밸브에 대한 개도율에 따른 손실계수(k) 비교에 관한 연구)

  • Kang, Chang-Won;Yi, Chung-Seob;Lee, Chi-Woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.9
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    • pp.63-69
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    • 2021
  • This study aims to determine the flow characteristics of a one-inch small ball valve and glove valve used in industrial plants. The flow was changed through an experimental equipment, and the internal flow characteristics of the valves were compared. Considering the pressure drop, the decrease in the slope of the ball valve based on the degree of the valve opening was relatively greater than that of the glove valve; further, the slope of the glove valve was gentle while the pressure drop was high. The flow velocity of the ball valve remains consistent after the valve was opened by 70%, whereas the flow velocity of the glove valve constantly increased. The valve loss factor of the ball valve was relatively low compared with that of the glove valve. When the valve was opened by 20%, which is the beginning stage of the valve opening, the valve loss factor of the ball valve was high and gradually became low. This is a structural problem of the ball valve, and the loss factor is significant because the flow path installed at the ball valve has a considerably small area. However, the overall loss factor of glove valve is high because it has a complicated structure of flow path.

Evaluation of the Effect on the Valve Flow Coefficient by Attached Fitting (밸브 후단 피팅에 따른 밸브 용량계수의 영향 평가)

  • Kang, Seung-Kyu;Lee, Won-Sik;Yoon, Joon-Yong;Min, Kyung-Wha
    • The KSFM Journal of Fluid Machinery
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    • v.6 no.4 s.21
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    • pp.29-37
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    • 2003
  • This study was undertaken to verify the effect of flow coefficient when a globe control valve was attached by different type of fitting. The valve flow coefficient is usually determined by measuring the flow rate and the pressure drop with the connection of straight pipe through the valve. The effect of different fitting that is mounted on the downstream of the valve is studied. Four types of fittings and three distances between the valve and a downstream fitting are compared parametrically to investigate the effect on the flow coefficient of it. Measured flow coefficient and numerically predicted value by using computational fluid dynamics were compared in detail. It is concluded that the flow coefficient is reduced if the fitting is attached after a valve, but the effect of different type of fitting is not crucial.

A Non-immersive 2D Virtual Reality System Using CCD Camera and Beam Projector (CCD 카메라와 빔 프로젝터를 이용한 비몰입형 2차원 가상현실 시스템)

  • 이민정;천미향;박동규
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04c
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    • pp.594-596
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    • 2003
  • 지금까지 구현된 대부분의 가상환경 시스템은 헤드마운트디스플레이(HMD), 트랙커, 핸드 글로브, 포스 피트백 센서등의 전문적인 장비를 이용하여 구현되었으며 인터액티브한 장면을 연출하기 위하여 고속의 하드웨어 사양을 필요로 하였다. 현재 이러한 장비는 전문가가 아니면 사용하기가 어렵고 또 장비의 비용이 매우 고가이기 때문에 대중화되기까지 상당한 시간이 소요될 것으로 예상된다. 본 논문은 이와 같은 전문적인 장비가 아닌 범용장비에 속하는 CCD 카메라와 빔 프로젝트를 활용하여 사용자가 인터액티브하게 참여할 수 있는 게임 시스템의 설계와 구현에 관한 논문이다. 이 시스템에서 사용자는 별도의 센스가 부착된 장비가 없이 간단한 색상 마커만을 가지고 컴퓨터가 생성한 가상 공간에서 빔 프로젝트로 구성한 가상 공간에서 캐릭터와의 실시간 게임을 즐길 수 있는 기능을 가지고 있다.

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