• Title/Summary/Keyword: prism

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Characteristic analysis of flowfield around a square prism having a detached splitter plate using the PIV (PIV에 의한 분리된 분할판을 가진 정방형주 주위의 유동장 특성 분석)

  • Ro, Ki-Deok
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.4
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    • pp.338-343
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    • 2013
  • The Flowfield characteristics of a square prism having a detached splitter plate at the wake region were investigated by visualization of the flow field using PIV. The experimental parameters were the width ratios(H/B=0.5~1.5) of the splitter plate to the prism width and the gap ratios (G/B=0~2) between the prism and the splitter plate. As the results the Strouhal number measured at the wake region of the detached splitter plate was decreased with the width ratio and the gap ratio. The clockwise vortex at the upside of the splitter plate and counterclockwise vortex at the downside were represented, the size of these vortices were increased with the width of the splitter plate. The reverse flow was represented at the wake region of the square prism having a detached splitter plate, the size of this reverse flow was increased with the width of the splitter plate.

Development of Dot Sight with Prism Beam Splitter (빔분리프리즘 도트사이트 장치의 개발)

  • Lee, Dong-Hee;Jung, Bo-Seon;Park, Seung-Hwan
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.4
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    • pp.519-524
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    • 2013
  • Purpose: This study relates to the development of dot-sight device, whose length is reduced, with a prism beam splitter. Methods: We developed a new dot-sight device whose length was reduced by eliminating the optical axis tilt of the doublet reflector to reduce the occurrence of the parallax and by redesigning the doublet reflector to use a prism beam splitter. Results: We could develop the new type dot-sight device having a prism beam splitter and the dot reticle generator and the doublet reflector, of which optical axises showed a T-letter type with the optical axis of the observer's eye. Conclusions: In this study, we designed and developed a new type dot sight employing a prism beam splitter that could be able to further enhance the accuracy of the fire in comparison with the traditional dot sight, thereby reducing the overall optical length of system. The new designed dot sight was able to be reduced 2.2 times on the overall optical length, and could be improved more than three times on the accuracy of shooting in the horizontal direction, than the traditional dot sight.

A study on the Application of Non Prism Totalstation to Facility Survey (시설물측량에서의 무프리즘 토털스테이션 활용성 연구)

  • 박경식;이현직;함창학
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.2
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    • pp.155-164
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    • 2003
  • The entrance of non prism totalstation brought the application possibility to many fields including a topographic survey and a facility measurement. In this research we would try to examine the errors and the problems which will be happened in measuring object with non prism totalstation and to evaluate the accuracy and applicability. For this purposes, We checked accuracy change according to the observation ang1e and material of the object, and analyzed how much accuracy was effected with the color of the object surface and laser divergency which is proportional to the distance. By measuring the facility practically and analyzing it's results, We evaluated possibility of practical use of a non prism totalstation for a facility measurement. Consequently, We propose that the observation accuracy of non prism totalstation is not depend on the hardness or material of the object and can get a good result only when we use non prism totalstation with coaxial focusing system for a facility survey.

Design and Experiment of an Optical System using a Prism with a High Enough Refractive Index for Wet Fingerprint Identification (물 묻은 지문을 인식하기 위한 프리즘 광학계의 설계 및 실험적 고찰)

  • Kang, Myung-Hoon;Kim, Jin-Su;Jung, Jin-Woo;Ko, Eun-Mi;Kim, Jae-Gu;Cho, Guan-Sik;Song, Han-Jung;Hwang, Jae-Mun
    • Korean Journal of Optics and Photonics
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    • v.18 no.6
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    • pp.395-400
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    • 2007
  • We propose a design and analysis of an optical system using a prism with a high enough refractive index for wet fingerprint identification. Important parameters including the tilting angle($\beta$) of the $1^{st}$ image plane, an anamorphic distortion, and a tilt of image plane are considered in terms of the apex angle of the prism($\alpha$) and refractive index of the prism material. Our suggestion on refractive index and apex angle of the prism corroborates well with experimental results.

Development of Day and Night Scope with BS Prism (BS 프리즘을 이용한 주야 조준경 개발)

  • Lee, Dong-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.3
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    • pp.339-344
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    • 2014
  • Purpose: This study relates to the development of the day and night scope using the reflecting surface of a BS (beam splitting) prism. Methods: We have placed the LCD panel and the dot reticle generator to the top and bottom of the reflecting surface of the BS prism, and have placed a reflector, which is designed to doublet type, in the front of the BS prism. Doing so, we have developed a new type of day and night scope, which is able to image the virtual image of dot reticle from the dot reticle generator to the direction of the observer, to make the observer survey the peripheral information of the outside target by 1x magnification, and to make the observer survey the image of the LCD panel directly. Results: We could develope a new type of day and night scope, which has the function of night scope as thermal image display device at night time and the function of day scope as dot sight at day time, by letting the reflective surface of the BS prism have the role of dot sight which reflects the dot reticle and have the role of reflective optical system by which the observer surveys the night thermal image displayed in LCD panel. Conclusions: In this study, we have developed the new type of day and night scope which is able to play the role of the day or night scope selectively, combining the existing dot sight and the existing night scope by using the BS prism. By doing so, we could design and fabricate the new type of day and night scope with the BS prism which can further increase the rapidity of firing and provide more convenience in the mounting of a firearm than the detachable combination of an existing dot sight and an existing night scope.

Development of Scope with Abbe-König Prism (아베-코닉 프리즘을 이용한 스코프 개발)

  • Lee, Dong-Hee;Park, Seung-Hwan
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.4
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    • pp.509-517
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    • 2013
  • Purpose: The purpose of this study is developing the 2.6 ${\times}$ optical scope with a Abbe-K$\ddot{o}$nig prism. Methods: First, considering the size of the effective aperture and the focal length of the objective lens, we designed an Abbe-K$\ddot{o}$nig prism. Next, we calculated the optical and geometric distances of Abbe-K$\ddot{o}$nig prism designed in this way. After allocating the focal length of the objective lens and the eyepiece lens so as to satisfy the magnification and optical effective distance of the entire system by using this calculation result, we completed the entire system by optimizing this optical system. Results: We were able to complete the optical scope of about 2.6 ${\times}$ magnification by designing an objective lens with a focal length of 63.13 mm which was composed of two pieces, an eyepiece with a focal length of 24.3 mm which was composed of four pieces, and an Abbe-K$\ddot{o}$nig prism with a face length 11.5 mm. Conclusions: We designed and fabricated an optical scope with 2.6 ${\times}$ magnification employing an Abbe-K$\ddot{o}$nig prism. Then, this system became the compacted optical system with a barrel diameter of 31 mm, characterized by an effective aperture of 12.0 mm and an effective optical barrel length of 103 mm and a resolution of 200 cycles/rad at 50% MTF criterion within the half viewing field angle of $6.42^{\circ}$.

Design of an Anamorphic Aspherical Prism Lens for the Head Mount Display (HMD용 회전 비대칭 비구면 프리즘 렌즈 설계)

  • Park, Seung-Hwan;Lee, Dong-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.4
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    • pp.83-88
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    • 2008
  • Purpose: To design an anamorphic aspherical prism lens for the HMD optical system. Methods: First, we get the initial data, needed in design, which are distances between each surface etc., by analyzing user's demended specifications and by drawing geometrically the shape of prism lens by using CAD. Based on these data and using 'ode V' which is an optical design software, we could progress the optimization in which we treat the coefficients of the anamorphic aspherical surface as the principal variables. To reduce the cost in DTM manufacturing, we would optimize the optical system with the transmitting surface, existed in the direction of video device among 3 surfaces of the prism lens, remaining as a plane. Results: we could design one anamorphic aspherical prism lens which has the finite ray aberration of 15 ${\mu}m$, the distortion of 0.5%, and the MTF value of 0.3 over at 36 lp/mm for the video device of 12 mm ${\times}$ 9 mm size. Conclusions: We designed a prism lens used for HMD. This prism lens has the optical capacities of 15 ${\mu}m$ finite ray aberration and 0.5% distortion for the video device of 12 mm ${\times}$ 9 mm size, and become the optical system having the MTF value of 0.3 over at 36 lp/mm.

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