• 제목/요약/키워드: Direct photography

검색결과 52건 처리시간 0.022초

예혼합 화염이 벽면에 충돌시 열전달 및 연소특성에 관한 실험적 연구 (The Experimental Study for Heat Transfer and Combustion Characteristics of Gaseous Impinging Jet Premixed Flame)

  • 정은규;조경민;김호영
    • 한국자동차공학회논문집
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    • 제4권6호
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    • pp.1-10
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    • 1996
  • In the present study, the structure and the characteristics of gaseous premixed flame impinging normal to the flat plate have been investigated experimentally. For the examination of the heat transfer and combustion characteristics, measurements of temperature, direct and schlieren photography were performed. The results of present study show that the length of inner flame becomes smaller as distance from nozzle exit to plate decrease. The width of flame becomes larger as air-fuel ratio decreases. The smaller Reynolds number at nozzle exit and the smaller distance from nozzle exit to plate lead to the higher heat transfer rate in the region of center of plate. As the air-fuel ratio decreases, the heat transfer at plate with moderate rate occurs on wide region.

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CW 레이저 스페클 사진법에 의한 스트레인 측정에 관한 연구 (A Study of Strain measurement by continuous wave Laser speckle photography)

  • 김경석;김충원;이승건
    • 한국정밀공학회지
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    • 제7권2호
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    • pp.65-73
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    • 1990
  • Speckle photography is a simple non-contacting method for analysing surface displacement. In its basic form, the object to be studied is illuminated with a beam of laser light from any convenient direction, and a double exposure photography of the surface recorded on the fine-grain film, the object is undergone the displacement to be measured between exposures. Like this, it allows the strain field to be evaluated in two dimensions. A direct experimental comparison of speckle photography with theoretical value on a notched tensile test specimen showed that serious errors could, however, occur due to local surface tilting and due to aberra- tions of the imaging lens. Methods of minimising these effects and those of the speckle de-correlation which occurs by the various conditions are discussed.

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에디토리얼 패션사진에 나타난 성별에 따른 젠더 이미지 표현 (Expressions of Gender Images According to Sex in Editorial Fashion Photography)

  • 최나리;우주형
    • 복식
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    • 제57권2호
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    • pp.143-154
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    • 2007
  • This study's purpose is how express gender image according to sex in editorial fashion photography. This study's objectives are the women's magazine Vogue, Harper's Bazaar and man's magazine GQ, Esquire published 2000-2005 within the country. The photography was classified with established a standard based on the precede studies. The photo is classified Gender image according to dress and its ornaments, model character and atmosphere by Sex Expression of femininity woman has exposure of body parts and emphasizing thin eyebrows and red lips, soft and mild image, modest and static pose. Man expressed femininity used ladylike color and pattern, erotic exposure of body and long hair style. Commonly emphasizing red lips, natural background of flower plant, S-line. For expression of masculinity man and woman are used masculinity item, short hair-style and thick eyebrows. And also emphasize square like chin and shoulder. Specially, woman used direct silhouette to conceal soft body curved line. The expressions of androgynous woman and man are colorful dress and make-up. Woman emphasized male face to show and man expressed soft image through hull of abundant material of fur. All two sex selected method that conceal body curved line and face to express sexless. Hiding characteristics of body and face make indistinct of sex. The gender is affected by atmosphere such as model and illumination background as much as clothes because of the editorial fashion photography.

층류 동축류 제트에서의 프로판 부상 화염에 관한 실험적 연구 (Lifted Flames in Laminar Coflow Jets of Propane)

  • 이종수;원상희;진성호;정석호
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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    • pp.61-67
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    • 2002
  • Characteristics of lifted flames in axisymmetric laminar coflow jets have been investigated experimentally. Approximate equations for velocity and concentration with virtual origins have been proposed to analyze the behavior of flames in coflow jets. Measuring Rayleigh intensity to investigate the concentration field. proposed approximate equations were confirmed. By using the results of OH PLIF, direct photography and Rayleigh scattering measurement, it is shown that the locations of maximum intensity in direct photography coincide with the tribrachial points in axisymmetric jets and the tribrachial points travel on the stoichiometric contour. For coflow jets, the experimental results of liftoff height have been successfully correlated with nozzle exit velocity using predicted behavior from proposed approximated equations. These results substantiate the stabilization mechanism in coflow jet is based on the balance between flame propagation speed and axial flow velocity, same as for the free jets.

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머리고정기(Cephalostat)를 이용한 표준임상사진술에서 사진계측법: 인체계측법과의 비교 (Photogrammetry Based on Standardized Clinical Photography using Cephalostat: Comparison with Anthropometric Analysis)

  • 권혁준;한기환;김준형;손대구
    • Archives of Plastic Surgery
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    • 제34권1호
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    • pp.24-36
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    • 2007
  • Purpose: Direct anthropometry is an ideal method for preoperative planning and postoperative evaluation in plastic surgery, but it requires highly skilled specialty. Indirect anthropometry, especially photogrammetry, is an alternative method. In photogrammetry, standardized clinical photography is essential. Photogrammetry-based standardized clinical photography has several advantages over direct anthropometry. It is easier to measure and has less chance to make errors during measurement. Furthermore, it is possible to repeat measurements, and available for follow up study based on permanent custody. But, it is still different from actual measurement, and inherently less accurate than anthropometry. Methods: The authors revised the standardized clinical photography and then, carried out photogrammetry using Photoshop(Adobe, U.S.A.), and compared each data with those of anthropometry. The subjects were 50 males and 50 females, undergraduate medical students in twenties. Standard head position was obtained from the wire, fixed to cephalostat which indicates the Frankfort horizontal plane. All photographs were taken at the same situation such as fixed position of light, subject and camera, etc. Results: Total 96 measurements, based on 40 landmarks, consist of linear measurements, angular measurements and inclinations include 3 measurements in head, 22 in face, 15 in orbit, 28 in nose, 16 in lip and mouth, and 12 in ear. Conclusion: Normal photogrammetric data of face of Korean in twenties was obtained. Reliable photogrammetric measurements, not significantly different from anthropometric measurement statistically, accounted for 44 in 96 measurements(45.8%). Anthropometric values different from those of photogrammetric values were obtained by multiplying coefficient by photogrammetric value.

레이저 스페클과 디지털 화상관련법을 이용한 변위 측정방법의 평가 (Evaluation of Displacement Measurement Technique Using Laser Speckle and Digital Image Correlation Method)

  • 강기주;이정현;전문창
    • 한국정밀공학회지
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    • 제20권6호
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    • pp.47-54
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    • 2003
  • As a tool for strain measurement to work with screw driven or hydraulic material test systems, in which mechanical vibration is inherent, SSDG (Speckle Strain/Displacement Gage), ESP (Electronic Speckle Photography) and its 3-dimension version SDSP are evaluated for the theory and practical appliance. Through tension test of steel strips, their validity and shortcomings are examined. As the results, it has been shown that, although SSDG and ESP provide direct measurement of in-plane strain in one direction, they are so sensitive to the out-plane displacement. On the other hand, SDSP which is aided with DIC (Digital Image Correlation) technique to trace the movement of the speckles provides not only in-plane 2-dimensional displacement field, but also out-of-plane displacement simultaneously. However, because the DIC is time-consuming, not automated yet and it needs post-processing to evaluate strain from the displacement field, SDSP appears to be not adequate as a real time sensor.

현대패션의 신체부위에 따른 에로티시즘[Eroticism]표현 - 에디토리얼 패션사진을 중심으로 - (Expression of Eroticism According to Body Part in Modern Fashion - Focused on Editorial Fashion Photography -)

  • 최나리;우주형
    • 복식
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    • 제56권9호
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    • pp.24-36
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    • 2006
  • The consumption became a virtue of social in 20th century, and this consumption culture created an ideal body image through mass media. Sexual image became a new standard of 'beauty' in a modern fashion, and designs which expressed sexual image appear every season. Individuals were fascinated with some parts of human body. These body parts are different based on the time period and the culture that the individual belonged to. This study focused on the erotic body parts and expression on the editorial fashion photography. Eroticism represented in the editorial fashion photographs can be divided into the expression by clothing design and by creating erotic atmospheres. Erotic expressions by clothing design can be presented by 1)exposing directly 2)exposing indirectly 3)emphasizing the body parts. The most frequently presented erotic body parts in fashion photographs were legs(25%), followed by the bodice with breast (21%), the waist (16%), the hip (12%), neck & shoulder (10%), arms (9%), and abdomen (7%). The results indicated that legs were considered to be a erotic body parts often than the traditionally referred erotic body parts, such as bodice with breast or hip. While direct exposing method (e.g., adhesion, see-though) was frequently used for other body parts.

레이저 스페클을 이용한 재료 변형 측정 (Measurement of Material Deformation Using Laser Speckle)

  • 전문창;강기주
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.688-694
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    • 2002
  • As a tool for strain measurement to work with screw driven or hydraulic material test systems, in which mechanical vibration is inherent, SSDG(Speckle Strain/Displacement Gage), ESP(Electronic Speckle Photography) and its 3-dimension version SDSP are investigated for the theory and practical appliance. Through tension test of steel strips, their validity and shortcomings are examined. As the results, it has been shown that, although SSDG and ESP provide direct measurement of in-plane strain in one direction, they are so sensitive to the out-plane displacement. On the other hand, SDSP which is aided with DIC (Digital Image Correlation) technique to trace the movement of the speckles provides not only in-plane 2-dimensional displacement field, but also out-of-plane displacement simultaneously. However, because the DIC is time-consuming, not automated yet and it needs post-processing to evaluate strain from the displacement field, SDSP appears to be not adequate as a real time sensor.

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직접분사식 수소연료의 분무 및 연소특성에 관한 연구 (A Study on the Characteristics of Injection and Combustion with Directly Injected Hydrogen Fuel)

  • 이성욱;기완수
    • 한국자동차공학회논문집
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    • 제15권5호
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    • pp.24-29
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    • 2007
  • This study aims to provide a fundamental data for directly injected hydrogen fuel engines. Spray, ignition and combustion characteristics of hydrogen were studied using constant volume chamber. For spray visualization, hydrogen was vertically injected into a combustion chamber at various condition, for example, injection pressure, ambient pressure. And an argon laser was used for the shadowgraph photography by applying optical method. Also, to investigate heat-release rate and flame propagations, spark was ignited on hydrogen injected at the different time after injection and the duration of injection was also changed. Processes of ignition and combustion were analyzed by heat-release rate calculated by pressure history and were observed by shadowgraph photography The results gave much knowledge of spray, ignition and combustion characteristics of hydrogen.

정적 용기내의 직접분사식 스파크 점화 성층 연소에 관한 연구 (A Study on Direct Injection Stratified Charge Combustion with Spark Ignition in Constant Volume Bomb)

  • 홍명석;김경석
    • 한국자동차공학회논문집
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    • 제2권5호
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    • pp.30-40
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    • 1994
  • The direct-injection stratified-charge engine has the advantages of higher thermal efficiency and less CO and $NO_x$ emission levels than conventional spark ignition engines. However, its actual utilization is prevented by high unburned hydrocarbon emission levels during light-load operations. In this paper, fundamental studies were carried out using a pancake type constant volume bomb. The effects of intensification of local premixing by tangential and radial fuel injection were examined experimentally. Unburned hydrocarbon emission levels with radial fuel injection were shown to be lower than those of tangential fuel injection cases. The stratification and mixing process of fuel jet and combustion process were observed by schlieren photography.

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