• 제목/요약/키워드: Uniformity factor

검색결과 195건 처리시간 0.032초

강의실 빛 환경의 층별 , 시간대별 비교연구 (A comparative study on the light environment of the classroom classified by floor , time)

  • 곽경숙
    • 한국주거학회논문집
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    • 제4권2호
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    • pp.1-9
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    • 1993
  • This study is a basic research to analyze and estimate the light environment of the classroom by serial correlation of time. Its purpose lies in the comparison by time period in order In select floor for laboratory and to calculate the uniformity factor. The proving ground is T building in W university, Which is five floor of central hall type. The subject of investigating is eight classrooms, four rooms in South and North, from the second floor that is net influenced by the shelter. The results that compared and estimated them in the illumination of daylight, Uniformity factor, Daylight factor, are as follows1. The illumination of classroom in South and North is over 10001x, but the classroom in North is good and the classroom in South excellent.2. The uniformity factor of classroom in South is good and that of classroom in North is normal.3. The daylight factor of each classroom is over 5% but the classroom in South is above that in North. The classroom in South surpasses the classroom in North in the general light environment and the classroom in third and fourth floor is so better than that in second and fifth floor in the condition of laboratory In the uniformity factor, the classroom in fourth can be better than any classroom.

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CFD를 활용한 DOC-DPF 조합의 유동 균질도 분석 (Flow Uniformity Analysis of DOC-DPF System using CFD)

  • 김태훈;박성욱
    • 한국분무공학회지
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    • 제24권3호
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    • pp.122-129
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    • 2019
  • Flow uniformity in aftertreatment system is an important factor in determining uniform catalytic reaction and filtration. In this study, variety types of DOC-DPF system design were analyzed to increase flow uniformity. For this analysis, ANSYS Fluent was used with porous media setup for DOC and DPF. Turbulent flow was modeled by standard $k-{\varepsilon}$ model excepting porous media. Uniformity index was utilized to evaluate the flow uniformity quantitatively. Reference design showed low velocity region because two large vortex were generated before baffle. When radius of DOC-DPF system was increased, exhaust pressure acting on the inlet decreases and velocity distribution was shifted to one side. When inlet pipe was set to axial center of DOC-DPF system velocity distribution was symmetric. However, flow was not dissipated until the front end of DOC and showed higher uniformity index. When the volume of DOC was reduced while fixed volume of entire DOC-DPF system and baffle plate is located downstream of the DOC-DPF system, there was improvement in uniformity index.

A study on modeling and measuring method of tire weight imbalances and improving reliability (ICCAS 2004)

  • Lee, Ki-Seong;Jeong, Tae-Woon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.1685-1688
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    • 2004
  • I propose a modeling of a mechanism for weight fire uniformity measurement of a tire and a way I interpret a Sampling signal by Loadcell through an analysis, and to measure fire uniformity in this study. Correct a weight fire uniformity measurement was possible through the production of conversion and influence factor of a signal with a basis with the model who was an oscillation mechanics enemy.

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산화막 CMP에서 발생하는 온도가 연마특성에 미치는 영향 (Effect of Temperature on Polishing Properties in Oxide CMP)

  • 김영진;박범영;김형재;정해도
    • 한국전기전자재료학회논문지
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    • 제21권2호
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    • pp.93-98
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    • 2008
  • We investigated the effect of process temperature on removal rate and non-uniformity based on single head kinematics in oxide CMP. Generally, it has been known that the temperature profile directly transfers to the non~uniformity of removal rate on the wafer, which has similar tendency with the sliding distance of wafer. Experimental results show that platen velocity is a dominant factor in removal rate as well as average temperature. However, the non-uniformity does not coincide between process temperature and removal rate, due to slurry accumulation and low deviation of temperature. Resultantly, the removal rate is strongly dependent on the rotational speed of platen, and its non -uniformity is controlled by the rotational speed of polishing head. It means lower WIWNU (With-in-wafer-non-uniformity) can be achieved in the region of higher head speed.

강의실 빛 환경에 대한 재실자의 주관적 평가 (The Subjective Evaluation on the Light Environment of Residents at Classrooms)

  • 곽경숙
    • 한국주거학회논문집
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    • 제7권1호
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    • pp.105-116
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    • 1996
  • The purpose of this study is to improve the quality of the light environment of classroom. To attain this purpose, this study estimated the physical factor and evaluation of the subjective response of classroon located in south and north in the summer and the winter. The results are as followed. 1. The evaluation of the illumination, uniformity factor, daylight factor as physical factor of light environment is good as classroom, but the classroom in south is better that that in north, the light environment in summer is better than winter. 2. The subjective response to light environment of classroom is positive on both seasons at all calssroom. Comparing summer with winter, I found that the difference of subjective response between both classrooms on summer is attentive. 3. The realtion between subjective response and physical factor of light environment in classroom is attentive on the light sense, content sense, uniformity.

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교반기 매개변수에 따른 교반형 전자파 잔향실의 특성 및 유용성 평가 (Mode-Stirred Reverberation Chamber Characteristic to Stirrer Parameter and Usefulness Evaluation)

  • 김광용;홍주일;허창수
    • 전기학회논문지
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    • 제59권9호
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    • pp.1652-1657
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    • 2010
  • This paper analyzes optimal stirrer parameter to improve field uniformity in a mode-stirred reverberation chamber. Stirrer parameter is varied about stirrer height and stirrer angle. Also we analyze quality factor, number of excited modes and stirrer efficiency that affect field uniformity. The results show good performance as higher as stirrer height. Isotropic field distribution is formed at $45^{\circ}$ stirrer angle. When stirrer angle varies, scattering characteristic of incident wave are changed. So electric field distribution in a mode-stirred reverberation chamber is also changed. Therefore, it affect field uniformity. The results expect to help that designs stirrer for get better field uniformity. Immunity test performed designed mode-stirred reverberation chamber for semiconductor that categorized by technology. Test result shows that good recurrence compared wave-guide immunity test.

Slit-Coater내의 Photo Resist의 코팅 특성 (Coating Characteristics of Photo Resist in a Slit-Coater)

  • 김장우;정진도;김성근
    • 반도체디스플레이기술학회지
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    • 제3권3호
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    • pp.41-44
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    • 2004
  • The aim of this study is the confirmation of the coating uniformity affected by the surface tension and wall attachment angle in a slit-coater model. In this work, we use the commercial code (Fluent) to solve the two-phase flow formed with air and photo resist numerically. The results show that the surface tension is the most important factor to determine the coating efficiency in the view of coating uniformity, and the coating uniformity is 2% for our slit-coater model and conditions. To improve the coating uniformity, it is in need of minimization of the sidewall effect of slit-coater.

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스캐너와 평균 밝기를 이용한 프린터 출력물의 색 균일도 추정 (Color Uniformity Estimation of Printouts Using a Scanner and Average Brightness)

  • 김지홍;최두현
    • 한국멀티미디어학회논문지
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    • 제12권7호
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    • pp.1016-1021
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    • 2009
  • 컬러 프린터의 성능을 결정하는 여러 요소 중 색 균일도는 프린터의 개발 단계에서나 완제품의 성능 평가 지표로 중요한 항목이다. 개발 현장에서는 현재 농도계를 사용하여 수동으로 색 균일도를 측정하고 그 측정 결과를 분석하여 성능을 평가한다. 본 논문에서는 스캐너와 평균 밝기를 사용하여 색 균일도를 자동으로 추정하는 방법을 제안한다. 제안된 방법은 기존의 방법에서 사용하는 패턴과 스캐너를 이용하여, 위치에 따른 색 균일도를 추정하며, 실험을 통해 추정된 데이터가 농도계로부터 측정된 농도와 유사함을 보인다. 아울러 균일도에 대한 분석과 함께 현재 판매되고 여는 프린터와 스캐너를 이용하여 제안한 알고리즘의 유용성을 검증한다.

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500 PS급 선박 SCR 반응기에서 디퓨저 각도와 면적비에 따른 유동균일도 수치해석 (Numerical Analysis on Flow Uniformity According to Area Ratio and Diffuser Angle in an SCR Reactor of a 500 PS-Class Ship)

  • 성홍석;박인성;장현;박창대;김현규;정경열;서정세
    • 한국생산제조학회지
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    • 제24권4호
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    • pp.394-399
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    • 2015
  • Because flow uniformity affects the life cycle and performance of the catalyst, it is an important design factor for selective catalytic reduction (SCR) systems. We examined how the diffuser angle and the area ratio of the inlet of the SCR reactor to the front of the catalyst affect flow uniformity. For the numerical analysis, we used STAR-CCM+, a common CFD software program. Analysis results showed that the larger the area ratio was, the less the flow uniformity was, and that the longer the diffuser length was, the greater the flow uniformity was. When the area ratio was greater than 1:5, the flow uniformity appeared very similar at the front of the catalyst. As a result, the spread time of the exhaust gas increased and the flow velocity decreased.

5 kW급 고온형 연료전지 촉매 연소기 유동 균일화 장치가 연소 특성에 미치는 영향 (Effect of Flow Uniformity Device on the Catalytic Combustor for 5 kW High Temperature Fuel Cell System)

  • 이상민;우현탁;안국영
    • 한국수소및신에너지학회논문집
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    • 제22권6호
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    • pp.878-883
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    • 2011
  • Effect of flow uniformity on the reaction characteristics of a catalytic combustor for high temperature fuel cell system has been experimentally investigated in the present study. One of the most important factor in designing catalytic combustion is to avoid hot spot in catalysts. In this regard, it is very important to secure flow uniformity of combustor inlet. A couple of perforated plates were applied at the front of catalyst region as flow uniformity device with minimal pressure drop. Results show that the velocity and temperature profile became more uniform when applying the flow uniformity device. CO and $CH_4$ emissions at the combustor exit were decreased and the average exit temperature was slightly increased with the flow uniformity device.