• 제목/요약/키워드: U-Factor

검색결과 1,476건 처리시간 0.029초

임의형상을 갖는 납작관에서의 혼합대류 열전달 해석 (Analysis of Mixed Convection Heat Transfer in Arbitrarily Shaped Flat Tubes)

  • 박희용;박경우;이상철
    • 설비공학논문집
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    • 제13권5호
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    • pp.398-410
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    • 2001
  • The flow and heat transfer characteristics for three-dimensional mixed convection flows in a radiator flat tube with U--shaped grooves are analyzed numerically. The flow and temperature fields are calculated by using the modified SIMPLE algorithm for irregular geometry. One tube specification among the various flat tube exchangers is recommended by considering the heat transfer and pressure drop. The effects of variation of coolant flow conditions and external air conditions on the flow and the thermal characteristics for the selected tube are investigated. the results show that inlet velocity of coolant flow is the very important factor in heat transfer and pressure drop, and top side is better position than the others as fin cleave to tube.

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Formation of Sensory Pigment Cells Requires Fibroblast Growth Factor Signaling during Ascidian Embryonic Development

  • Kim, Gil-Jung
    • Animal cells and systems
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    • 제7권3호
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    • pp.221-225
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    • 2003
  • The tadpole larva of the ascidian Halocynthia roretzi has two sensory pigment cells in its brain vesicle. To elucidate the temporal requirement for FGF signaling in formation of the pigment cells, embryos were treated with an FGF receptor 1 inhibitor, SU5402, or an MEK inhibitor, U0126 during various embryonic stages. In the present study, it is shown that the embryos treated with SU5402 from the 16-cell stage to the early gastrula stage do not form pigment cells, whereas those treated after the early gastrula stage form pigment cells. In pigment cell formation, embryos suddenly exhibited the sensitivity to SU5402 only for 1 h at the neural plate stage(-4 h after the beginning of gastrulation). When U0126 treatment was carried out at various stages between the 8-cell and late neurula stages, the embryos scarcely formed pigment cells. Pigment cell formation occurred when the embryos were placed in U0126 at early tail bud stage. These results indicate that FGF signaling is involved in pigment cell formation at two separate processes during ascidian embryogenesis, whereas more prolonged period is required for MEK signaling.

한국형 가족 기능 측정 도구 개발을 위한 연구 - 만성질환아 가족을 대상으로 - (A Study on the Development of the Korean Family Functioning Scale.)

  • 이인숙;박영숙;송미순;이은옥;;박연환;최경원;진영란;김대희
    • 대한간호학회지
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    • 제32권3호
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    • pp.395-405
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    • 2002
  • The purpose of this study was to develop the instrument to measure family functioning for Korean family with a chronic ill child, and to test the validity and reliability of the instrument. Method: The items of instrument were consisted based on researchers' previous study of concept analysis of the Korean family functioning. Twenty six item scale was developed with six domains. In order to test reliability and validity of the scale, data were collected from the 231 families, who have a child with a chronic illness. Data was collected between August and September in 2001 in a General Hospital in Seoul, Korea. Result: The results were as follows: As a result of the item analysis, 24 items were selected from the total of 26 items, excluding items with low correlation with total scale. Six factors were evolved by factor analysis. Six factors explained 61.4% of the total variance. The first factor 'Affective bonding' explained 15.4%, 2nd factor 'External relationship' 11.8%, 3rd factor 'Family norm' 10.5%, 4th factor 'Role and responsibilities' 8.3%, 5th factor ' Communication' 7.9%, and the 6th factor 'Financial resource' explained 7.3%. Cronbach's $\alpha$ coefficient of this scale was .87 and Guttman spilt- half coefficient was .84. Conclusion: The study support the reliability and validity of the scale. There were distinct differences in dimensions of family functioning scales developed in the U. S.

U-플랜지 트러스 보의 구조 내력에 관한 실험 연구 (Experimental Study on the Structural Capacity of the U-Flanged Truss Steel Beam)

  • 오명호;김영호;강재윤;김명한
    • 한국공간구조학회논문집
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    • 제18권4호
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    • pp.113-121
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    • 2018
  • U-flanged truss beam is composed of u-shaped upper steel flange, lower steel plate of 8mm or more thickness, and connecting lattice bars. Upper flange and lower plate are connected by the diagonal lattice bars welded on the upper and lower sides. In this study the structural experiments on the U-flanged truss beams with various shapes of upper flange were performed, and the flexural and shear capacities of U-flanged truss beam in the construction stage were evaluated. The principal test parameters were the shape of upper flange and the alignment space of diagonal lattice bars. In all the test specimens, the peak loads were determined by the buckling of lattice bar regardless of the upper flange shape. The test results have shown that the buckling of lattice bar is very important design factor and there is no need to reinforce the basic u-shaped upper flange. However, the early lattice buckling occurred in the truss beam with upper steel bars because of the insufficient strength and stiffness of upper chord, and the reinforcement in the upper chord is necessary. The formulae of Eurocode 3 (2005) have presented more exact evaluations of lattice buckling load than those of KBC 2016.

플로우 이론을 이용한 u-융복합 관광정보3.0 의 융복합 콘텐츠 정보품질 설계 (Design of Convergence Contents information quality of u-convergence tourist information3.0 using flow Theory)

  • 선수균;이승우
    • 디지털융복합연구
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    • 제13권9호
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    • pp.191-199
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    • 2015
  • 본 논문은 플로우 이론을 이용한 u-흉복합 관광정보3.0 시스템을 제안한다. 관광객의 즐거움을 극대화하기 위한 u-도전감과 u-숙련도를 생성한 것이 u-융복합 관광정보3.0 이다. 이것은 콘텐츠 정보품질의 도전감과 숙련도를 잘 조절하여 관광객의 즐거움을 극대화하기 위한 분석이다. 콘텐츠 정보품질의 도전감은 u-도전감의 선행요인인 콘텐츠 지속성, 관광동기 충족성을 분석할 수 있는 데이터를 생성할 수 있다. 콘텐츠 정보품질의 숙련도는 관광객의 u-숙련도의 선행요인인 숙달된 능력, 사용가능성, 인터넷신뢰성, 정보적시성, 앱검색능력을 분석할 수 있는 데이터를 생성할 수 있다. 그 결과는 메타 모델화를 생성하여 최적의 즐거움에 도달함을 콘텐츠 정보품질 극대화라 한다. 관광정보 콘텐츠의 정보품질의 도전감과 숙련도를 구현은 관광객의 즐거움을 데이터화하여 파악할 수 있다는 장점이 있다. 향후 국가직무 능력 표준에 적용하여 직무의 즐거움을 극대화 할 수 있을 것으로 기대된다.

열차하중의 주행에 의한 트러스교의 동적응답에 관한 연구 (A Study on Dynamic Response of Truss Bridge due to Moving Train Loads)

  • 장동일;최강희;이종득
    • 대한토목학회논문집
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    • 제9권2호
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    • pp.1-10
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    • 1989
  • 본 연구에서는 열차가 일정한 속도로 주행할 때 트러스교에 얼어나는 동적응답을 구해보았다. 해석은 Householder 변환과 QL법을 이용하여 고유치해석을 실시한 후 이를 토대로 모든중첩법에 의해 동적응답을 구했으며, 이것의 타당성을 밝히기 위해서는 먼저 아주 느린 속도로 하중이 주행할 때 얻어지는 응답을 정적해석프로그램에 의한 결과치와 비교하였고, 동적응답은 직접 적분법에 의한 결과 치와 비교해 보았다. 그리고 이를 토대로 열차의 속도와 형태의 변화에 따른 동적확대계수의 변화를 살펴보았으며, 또한 그것들을 시방서 규정과 비교해 보았다. 그 결과 열차의 속도가 낮은 경우 동적확대계수는 열차의 형태에 관계없이 비교적 낯은 값이 있었으나 속도가 높아질수록 형태에 따라 크게 다르고, 전도차 및 U. I. C. 하중의 경우는 그값이 시방서 규정을 초과하는 경우도 있음을 알수 있었다.

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Bump 회로와 인접픽셀 기반의 이미지 신호 Edge Detector (Image Edge Detector Based on a Bump Circuit and the Neighbor Pixels)

  • 오광석;이상진;조경록
    • 전자공학회논문지
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    • 제50권7호
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    • pp.149-156
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    • 2013
  • 본 논문에서는 bump 회로를 이용한 하드웨어 기반의 윤곽선 검출 회로를 제안한다. 하나의 픽셀은 빛을 전기적인 신호로 변환하는 active pixel sensor (APS)와 주변 픽셀의 밝기 차이를 비교하는 bump회로로 구성된다. 제안하는 회로는 $64{\times}64$의 이미지를 대상으로하며, 각 열(column)마다 비교기를 공유한다. 비교기는 외부에서 인가되는 기준전압을 통해 최종적으로 대상픽셀의 윤곽선 여부를 판별한다. 또한 기존의 4개 혹은 그 이상의 픽셀 데이터를 비교하는 윤곽선 검출 알고리즘을 상대적으로 간소화하여 대상픽셀을 포함하여 3개의 픽셀만으로 윤곽선 검출을 가능토록 제안하였다. 따라서 하나의 픽셀에 비교적 적은 수의 트랜지스터로 구성하였다. 따라서 제한적인 픽셀 크기에서 fill factor를 충분히 확보함으로써 수용 가능한 조도의 범위를 확장하였고, 기준전압을 외부에서 입력 받기 때문에 윤곽선 레벨을 조절 할 수 있다. Bump 회로기반의 윤곽선 검출 회로는 0.18um CMOS 공정에서 설계되었으며, 1.8V의 공급전압에서 픽셀 당 0.9uW의 전력 소모율, 34%의 fill factor을 갖는다. 이는 기존회로대비 전력 소모율을 90% 개선하였고, 기존 회로에 비하여 면적은 약 18.7%, fill factor는 약 16%를 더 확보하였다.

Prediction of rock fragmentation and design of blasting pattern based on 3-D spatial distribution of rock factor

  • 심현진;한창연;남현우
    • 지반과기술
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    • 제3권3호
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    • pp.15-22
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    • 2006
  • The optimum blasting pattern to excavate a quarry efficiently and economically can be determined based on the minimum production cost, which is generally estimated according to rock fragmentation. Therefore, it is a critical problem to predict fragment size distribution of blasted rocks over an entire quarry. By comparing various prediction models, it can be ascertained that the result obtained from Kuz-Ram model relatively coincides with that of field measurements. Kuz-Ram model uses the concept of rock factor to signify conditions of rock mass such as block size, rock jointing, strength and others. For the evaluation of total production cost, it is imperative to estimate 3-D spatial distribution of rock factor for the entire quarry. In this study, a sequential indicator simulation technique is adopted for estimation of spatial distribution of rock factor due to its higher reproducibility of spatial variability and distribution models than Kriging methods. Further, this can reduce the uncertainty of predictor using distribution information of sample data. The entire quarry is classified into three types of rock mass and optimum blasting pattern is proposed for each type based on 3-D spatial distribution of rock factor. In addition, plane maps of rock factor distribution for each ground level are provided to estimate production costs for each process and to make a plan for an optimum blasting pattern.

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강원도 영동권 지역 대학생들의 외식동기에 의한 정보탐색방법 (The Information Search Method According to Eating-out Motivation of College Students in Eastern Area of Kangwon Province)

  • 윤태환
    • 한국식품조리과학회지
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    • 제22권2호
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    • pp.213-221
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    • 2006
  • Although motivation and information search have both been studied continuously and separately as important marketing strategies, the relation between cause and effect has received little research attention. Therefore the objective of this study was to research the causal relationships between motivation and information search method. Frequency analysis and reliability analysis, factor analysis, and SEM(Structure Equation Model) were adopted to analyze the data. Motivation was divided into 5 factors which significantly influenced information search method. Factor 1, 'Reception and congratulation', influenced information search positively through 'newspaper, magazine', and 'word of mouth' but negatively through 'TV-advertising' and 'Flyer, Press copy'. Factor 2, 'Change of dietary life', influenced positively 'TV-advertising'. Factor 3, 'Economic saving', influenced positively 'newspaper, magazine', and 'the e-mail's advertising' Factor 4, 'Preference motivation', influenced negatively 'word of mouth' Factor 5, 'Advertisement and companion's need', influenced positively 'newspaper, magazine', and 'the e-mail's advertising' but negatively 'TV-advertising' As a result, customers appeared to choose various information search methods according to their eating-out motivation. 'The e-mail's advertising', and 'word of mouth' are popular among customers' information search methods. Therefore, food-service corporations need to try eliminating negative images of various advertisements and activate positive word of mouth marketing, promotion through internet.

종합병원 간호사의 간호권력 인식에 관한 연구 (A Study of Nursing Power Perception for Nurse in General Hospital)

  • 인경선
    • 한국보건간호학회지
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    • 제7권2호
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    • pp.67-76
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    • 1993
  • This study was conducted to investigate the nurses' recognition extent of nursing power and related factors. It was performed in a private university hospital using questionaire papers from Jul. 11 to Jul. 20, 1993. The collected data were in number of 209, and they were handled and analyzed by computer program (SPSS). Through above process, we got meaningful results as follow. 1. The factor concerned with whether the nursing department show its independent power or not was 4.1 on an average. Consequently above results showed that the independent power roles as a important factor. The factor concerned with study and research was 3.9 on an average. So that the extension of learning was also a comparatively important nursing power. But ensuring good material environment was merely 1.6 on an average. So it was understood as less important nursing power. 2. Between the factor concerned with enforcement of independence of nursing department and the factor concerned with extension of learning, there was positive correlation of 0.32 Pearson's Correlation Coefficent. It can be interpreted as the effort of extension of learning go side by side with the showing of independent power of nursing department. As a result the power of nursing become strong. And between the factor concerned with enforcenment of independence of nursing department and the ensuring o(good material environment, there was negative correlation of -0.28 Pearson's Correaltion Coefficint. It can be interpreted as the stronger the independent power of nursing, the more overlooked the recognized of material environment of nurses.

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