• 제목/요약/키워드: Quick

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비압축성 Navier-Stokes 방정식의 해석을 위한 MQUICK 상류해법 (MQUICK Upwind Scheme for the Incompressible Navier-Stokes Equations)

  • 신병록;정소추 이명
    • 한국전산유체공학회지
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    • 제4권1호
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    • pp.41-52
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    • 1999
  • 이 논문에서는, QUICK해법의 불안정성을 개량하므로써, 수치계산에 있어서 수렴이 빠르고, 수치적으로 안정한 계산을 할 수 있는 새로운 MQUICK 상류해법을 제안하고, 이를 비압축성 층류유동의 계산에 적용하였다. 또한, 해법의 정확성, 안정성, 수렴속도에 대한 검토를 통하여 본 MQUICK 상류해법의 유효성과 타당성이 평가되었다. 이 해법에서는 인공산일의 가감을 조절하기 위하여 가중계수 α를 써서 정식화 하였고, 위의 검토를 통하여 α의 최적값을 조사하였다. 이 해법을 SMAC 음해법에 적용하여 2 차원 공동유동, 3 차원 덕트유동과 같은 몇몇 표준문제를 계산하고, 계산된 결과를 실험값 또는, 3 차 정확도의 상류해법 및 QUICK해법에 의한 결과 들과 비교 하므로써, 본 MQUICK 상류해법이 위의 다른 해법에 비하여 안정하고, 유효성이 높은 해법임을 확인 하였다.

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THE USE OF QUICKS CAT WIND TO ESTIMATE THE VERTICAL VELOCITY IN TYPHOON AND SNOWSTORM

  • Heol Ki-young;Ha Kyung-Ja;Lee Dong-Kyu;Jeong Jin-Yong
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.54-57
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    • 2005
  • This study examines moisture supplement from the warm ocean in snowfalls of two cases and heavy rainfall of Typhoon case. The QuickSCAT wind is used to evaluate the convergence of moisture fluxes in the storms from the sea in estimation of the amount of heavy snowstorm and rainfall. The results show that enough water vapor transport from ocean to atmosphere induced the severe storms, because strong QuickSCAT -derived vertical velocity nearly concurred with heavy snowfall and rainfall. In the present study, we attempted to show that QuickSCAT wind can be used to forecast the severe weather events, such as heavy snowfall and rainfalls.

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A Study on the Improvement of Release Application Characteristics of Pneumatic Brakes for Freight Train

  • Nam, Seong-Won;Kim, Hyeong-Jin
    • Journal of Mechanical Science and Technology
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    • 제16권6호
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    • pp.776-784
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    • 2002
  • We have performed experimental studies for the improvements of pneumatic brake systems of freight trains. Currently, most of the freight trains operated by the Korean National Railroad have either empty-load or diaphragm type brake systems. In this study, appropriate methods that the air pressure characteristics in both type of brake systems are in accordance with each other have been investigated. We have also performed running tests using a 30 car-train set to design optimum capacity of a quick release valve. The test results show that the quick release valve is considerably effective in shortening the release time of the diaphragm type brake system. In the case of a normal brake application, the diaphragm type brake system with the quick release valve reduces the release time to 34% of that of the system without the quick release valve. This release time is almost equivalent to that of the empty-load type brake system. Accordance of braking performance in different types of brake systems in a train set is expected to prevent wheel flats and to reduce maintenance costs.

Quick Evaluations of the KOMPSAT-1 Orbit Maneuvers Using Small Sets of Real-time GPS Navigation Solutions

  • Lee, Byoung-Sun;Lee, Jeong-Sook;Kim, Jae-Hoon
    • Transactions on Control, Automation and Systems Engineering
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    • 제3권3호
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    • pp.196-202
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    • 2001
  • Quick evaluations of two in-plane orbit maneuvers using small sets of real-time GPS navigation solutions were performed for the KOMPSAT-1 spacecraft operation. Real-time GPS navigation solutions of the KOMPSAT-1 were collected during the Korean Ground Station(KGS) pass. Only a few sets of position and velocity data after completion of the thruster firing were used for the quick maneuver evaluations. The results were used for antenna pointing data predictions for the next station contact. Normal orbit maneuver evaluations using large sets of playback GPS navigation solutions were also performed and the result were compared with the quick evaluation results.

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Quick Evaluation of Spacecraft Orbit Maneuver Using Small Sets of Real-time GPS Navigation Solutions

  • Lee, Byoung-Sun;Lee, Ho-Jin;Lee, Seong-Pal;Kim, Jong-Ah;Park, Hae-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.458-458
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    • 2000
  • Quick evaluations of two in-plane orbit maneuvers using small see of real-time CPS navigation solutions were peformed lot the KOMPSAT-1 spacecraft operation. Real-time GPS navigation solutions of the KOMPSAT-1 were collected during the Korean Ground Station(KGS) pass. Only a few sets of position and velocity data after completion of the thruster firing were used for the quick maneuver evaluations. The results were used for antenna pointing data predictions for the next station contact. Normal orbit maneuver evaluations using large see of playback GPS navigation solutions were also performed and the result were compared with the quick evaluation results.

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Quick Bird 정사영상을 이용한 지형도 갱신 (Update of Topographic Map using QuickBird Orthoimage)

  • 이창경;우현권;정인준
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2004년도 추계학술발표회 논문집
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    • pp.295-301
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    • 2004
  • Satellite captures images periodically and economically over the area wider than aerial photographs, and reconnaissance to unapproachable area. For these advantages, mapping using high resolution satellite image has high potentials of marketability and development. Therefore, utilization of satellite image in mapping and GIS is expected to be growing and research on describable feature, positional accuracy and, possible mapping scale is urgently needed. This research presented that Quick Bird orthoimage could be used to update digital map on a scale of 1:5,000. Quick Bird image was corrected geometrically based on ground control points. DEM was generated using height data of digital topographic map. The orthoimge was produced by digital differential rectification based on DEM which was generated using height data of digital topographic map(scale 1;5,000 and 1;1,000). When the digital topographic map was overlaid with the orthoimage, it was very easy to find changed region or new features builded after the map compiled.

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포스코의 Quick Six Sigma 개선에 관한 연구 (A Study on Improving the Quick Six Sigma of Posco)

  • 윤태웅;이민정
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2017년도 제56차 하계학술대회논문집 25권2호
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    • pp.178-179
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    • 2017
  • 우리나라의 최대 철강회사인 포스코는 2005년부터 품질개선을 위해서 포스코 자체의 혁신방법론인 QSS+(Quick Six Sigma)을 개발하여 실시하고 있다. QSS+는 회사 전체 직원이 개선 실천 학습을 하고, 지속적인 낭비제거를 통해 부가가치를 창출하는 활동으로 '일상개선 활동, 과제 활동, 솔선/격려활동, 인재양성' 4개의 축으로 운영되고 있다. 또한 QSS+는 오랜 시간에 걸쳐 정착되어 정부 기관, 기업, 그룹사, 외주파트너사, 공급사 및 다양한 분야에서 우수 혁신 활동 사례로 벤치마킹을 실시하고 있다. 매년 현장에서 활동하는 포스코 QSS+ 현 수준을 정확히 판단하고 향후 방향성을 제시하는 QSS+ 충실도 평가 기준을 개선하기 위하여 AHP 분석 방법을 통해 평가 항목을 분석하고 현장이 반영된 'QSS+ 평가 기준'을 제시하고자 한다.

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생석회파일에 의한 연약지반개량효과 (The Improvement Effects of Soft Ground by Quick Lime Pile)

  • 천병식;고갑수;장은석;임지섭;이용한
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1999년도 춘계학술대회 논문집
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    • pp.383-389
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    • 1999
  • This paper is a study on the improvement effects by quick lime pile through theoretical analysis and in-situ construction test. Effects of strength increase is studied to verify the improvement effects of soft ground arounding quick lime pile. First, engineering characteristics of quick lime and ground was studied, in the second place, laboratory test(consolidation test, triaxial compression test) and in-situ test(portable cone penetration test, vane test) were peformed for verification of strength increase of adjacent ground. Finally, the results of in-situ test were compared with those of theorecal study. From in-situ test results, strength at 28th curing days(6.11-6.55t/㎡) was twice as great as strength before improvement(3.06t/㎡) and was slightly greater than theoretical value(4.95t/㎡).

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국내 패션산업의 Quick Response System 추진 현황과 문제점 (Implementation Issues to Quick Response System in Korean Fashion Industry)

  • 신상무
    • 한국전자거래학회지
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    • 제3권1호
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    • pp.175-194
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    • 1998
  • The purpose of this study is to examine the current status of Quick Response adoption, and to recognize the implementation problems of QR system in the Korean fashion industry. We reviewed the theoretical background of QR system, analyzed the current status of QR adoption, and identified critical issues to implement the system in our fashion business environment. Previous literatures and information gained from communication service organizations were used for this study The major problems recognized are lack of inter-organizational information network, closed supply channels, non-standardization of QR implementation, and low level of information technology usage including KAN, POS, and EDI. Strong mutual partnership between streams for shared common goals and clear QR mind setting of top management with commitment to information sharing are considered needed for the successful adoption of QR system in domestic fashion industry.

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급결제를 이용한 EVA 분말수지 혼입 폴리머 시멘트 모르타르의 초기강도 특성 (Early Strength Properties of EVA Polymer Powder-Modified Mortars with Quick Setting Agent)

  • 조영철;최낙운;이철웅;양석우;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.309-312
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    • 2005
  • Admixture compounds for shortening setting time and accelerating early strength development of EVA polymer powder-modified mortars were made by mixing various quick setting agents. As a result, the quick setting agents contribute to strength development of the mortars in the early curing age of 168h or less. In the viewpoint of early strength development of EVA polymer powder-modified mortars, an quick setting agent content of 20$\%$ is recommended. Early strength of EVA polymer powder-modified mortars expresses the excellent strength with 5$\%$, 10$\%$ of rates of polymer mixing. The rate of polymer mixing was able to be adjusted and flexural strength which is a predeterminded initial strength was also able to satisfy 3MPa(s).

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