• Title/Summary/Keyword: Slit shape

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A Study of Tool Planning for FRT-PLR-L/R Stamping Process by using Forming Analysis (성형해석을 이용한 프론트 필라의 성형 공법 개발에 관한 연구)

  • Jung, Dong-Won;Ko, Dae-Lim
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.10
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    • pp.890-896
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    • 2008
  • Sheet metal forming is one of the most useful and important method in manufacturing of the autobody panels because of the excellent production rate. The objectives of sheet metal forming processes are getting a desired geometrical shape of products with good quality, low cost and reasonable lead time. In this paper, we examined the validity of finite element method analysis on the automobile FRT-PLR-L/R stamping process by using the lancing engineering method. Lancing is a press operation in which a single-line cut or slit is made on part way across the strip stock, without removing any metal. As a result, it has shown that the proper lancing engineering method could prevent fracturing by improving sheet metal flow.

The Characteristics of Soot at the Post-Flame Region in Jet Diffusion Flames Added Carbon Dioxide (이산화탄소가 첨가된 제트확산화염 후류에서의 매연 특성)

  • Ji, Jung-Hoon;Lee, Eui-Ju
    • Journal of the Korean Society of Safety
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    • v.25 no.6
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    • pp.9-13
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    • 2010
  • An experimental study for characteristics of soot were conducted at the post-flame region in jet diffusion flames, where carbon dioxide was used as additives in oxidizer stream. Light-extinction method was performed using He-Ne laser with wave length at 632.8nm for the measurement of relative soot density and soot volume fraction with dimensionless extinction coefficient, $K_e$ and mass specific extinction coefficient, ${\sigma}_s$. To increase of resolution, laser light was modified for sheet-form using concave, convex lenses and slit. C/H ratio was introduced for quantitative analysis of soot growth which is expressed by carbonization and dehydrogen. Also transmission electron microscopy(TEM) was used for observation of morphological shape. The results show that the relative soot density in the post-flame region was lower when carbon dioxide was added in oxidizer stream because of reduction of flame temperature.

Treatment of descemetocele with deep keratotomy combined with a nictitating membrane flap in a dog

  • Manbok Jeong
    • Korean Journal of Veterinary Research
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    • v.63 no.2
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    • pp.20.1-20.4
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    • 2023
  • A 10-year-old, spayed female, Maltese dog presented with a 2-day history of severe left eye squint. Slit-lamp biomicroscopy showed a deep corneal defect stained into a doughnut shape together with hypopyon in the anterior chamber. Based on these results, a diagnosis of descemetocele and uveitis in the left eye was made. Deep keratotomy combined with a nictitating membrane flap effectively resolved the descemetocele without complications. The surgical procedures performed on this patient were easy and effective, and could be used as an alternative to graft surgery for descemetocele treatment.

MEMS Fabrication of Microchannel with Poly-Si Layer for Application to Microchip Electrophoresis (마이크로 칩 전기영동에 응용하기 위한 다결정 실리콘 층이 형성된 마이크로 채널의 MEMS 가공 제작)

  • Kim, Tae-Ha;Kim, Da-Young;Chun, Myung-Suk;Lee, Sang-Soon
    • Korean Chemical Engineering Research
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    • v.44 no.5
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    • pp.513-519
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    • 2006
  • We developed two kinds of the microchip for application to electrophoresis based on both glass and quartz employing the MEMS fabrications. The poly-Si layer deposited onto the bonding interface apart from channel regions can play a role as the optical slit cutting off the stray light in order to concentrate the UV ray, from which it is possible to improve the signal-to-noise (S/N) ratio of the detection on a chip. In the glass chip, the deposited poly-Si layer had an important function of the etch mask and provided the bonding surface properly enabling the anodic bonding. The glass wafer including more impurities than quartz one results in the higher surface roughness of the channel wall, which affects subsequently on the microflow behavior of the sample solutions. In order to solve this problem, we prepared here the mixed etchant consisting HF and $NH_4F$ solutions, by which the surface roughness was reduced. Both the shape and the dimension of each channel were observed, and the electroosmotic flow velocities were measured as 0.5 mm/s for quartz and 0.36 mm/s for glass channel by implementing the microchip electrophoresis. Applying the optical slit with poly-Si layer provides that the S/N ratio of the peak is increased as ca. 2 times for quartz chip and ca. 3 times for glass chip. The maximum UV absorbance is also enhanced with ca. 1.6 and 1.7 times, respectively.

A Study on the Image Changes of an Eye Shape according to Eyelash Design (속눈썹디자인에 따른 눈 형태의 이미지변화 연구)

  • Park, Jeong Shin
    • Journal of Fashion Business
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    • v.21 no.1
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    • pp.58-73
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    • 2017
  • The purpose of this study was to examine the need of the eyelash design area and the changes of an eye image according to eyelash design. Methodology included both a theoretical research and an empirical research. The theoretical research reviewed previous researches and technical books. The empirical research divided eye shapes, complemented the defect of eye shapes, and examined resulting image changes. A mechanical way was performed for treatment because it was more efficient than a manual way. A J-curl type was used. Eye length was divided into five and the point was determined. The length and density of curl were changed in each point to maximize a treatment effect. As a result, eye images were changed as follows. First, round eyes became stable. Slit eyes became vivid and soft. Wide-set eyes became intelligent and narrow-set eyes became smooth. Large eyes were naturally gradated and small eyes became larger. Double-eyelid eyes became stable and elegant and single-eyelid eyes became gentle and soft. Bulging eyes became easy and soft and sunken eyes became smooth. Peaked eyes became gentle and soft and sleepy eyes became strong and vivid. Based on the findings, eyelash design can play a role in changing an image according to eye shapes. In particular, a speed eyelash extension device to extend eyelash can reduce working hours and gradate only by angle control. It can complement the defect of eyes according to the design of each shape and change into a better image.

Comparison of Four Major Scarab Beetles, Ectinohoplia rufipes, Adoretus tenuimaculatus, Exomala orientalis and Popillia quadriguttata in Golf Courses (골프장 발생 주요 풍뎅이 4종, 주황긴다리풍뎅이, 주둥무늬차색풍뎅이, 등얼룩풍뎅이, 녹색콩풍뎅이의 비교)

  • 추호렬;이동운;박지웅;이종원
    • Asian Journal of Turfgrass Science
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    • v.13 no.2
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    • pp.101-112
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    • 1999
  • Four major scarab beetles, Ectinohoplia rufipes, Adoretus tenuimaculatus, Exomala orientalis and Popillia quadriguttata were obserbved in golf courses. Morphological characters of adults and larvae, feeding habit, mounds by grubs, and outbreak time were inbestigated. Body lengths of E. rufipes and A. tenuimaculatus were 11.5mm and 9.7-11.3mm, respectively and those of E. orientalis and P. quadriguttata were 8.0-13.5mm and 7.6-12.7mm, respectively. Adult of E. rufipes had a tendency to raise hind legs during the feeding and mating but showed no death feigning. On the contrary, A. tenuimaculatus adult did not raise its hind legs during the feding and showed death feigning and dropped to earth when disturbed. E. orientalis adults were mainly found from the flowers of chestnut trees in the daytime and P. quadriguttata adults were chiefly found from soft leaves of herbaceous plants in golf courses. White grubs of E. rufipes and A. tenuimaculatus did not have longitudinal and transversal seatae on anal part but setae on the raster were hooked. The shape of anal slit was Y-shape in E. rufipes and crescent-shape in A. tenuimaculatus. White grubs of E. orientalis had ten to sixteen longitudinal setae on raster and those of P. quadriguttata had medially two conspicuous rows of six or seven shorter straight setae forming a V. Adults of E. rufipes mainly fed on front part of leaves but those of A. tenuimaculatus fed on hind part of leaves. Mounds by earthworms and white grubs were different depending on species. Earthworm piled up sticky soil around exit hole but E. orientalis adult scattered soil one part of exit hole and A. tenuimaculatus adult scattered soil evenly around exit hole. Outbreak time of E. rufipes and A. tenuimaculatus was early May and that of E. orientalis and P. quadriguttata was late May.

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A Study on the 3D Shape Reconstruction Algorithm of an Indoor Environment Using Active Stereo Vision (능동 스테레오 비젼을 이용한 실내환경의 3차원 형상 재구성 알고리즘)

  • Byun, Ki-Won;Joo, Jae-Heum;Nam, Ki-Gon
    • Journal of the Institute of Convergence Signal Processing
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    • v.10 no.1
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    • pp.13-22
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    • 2009
  • In this paper, we propose the 3D shape reconstruction method that combine the mosaic method and the active stereo matching using the laser beam. The active stereo matching method detects the position information of the irradiated laser beam on object by analyzing the color and brightness variation of left and right image, and acquires the depth information in epipolar line. The mosaic method extracts feature point of image by using harris comer detection and matches the same keypoint between the sequence of images using the keypoint descriptor index method and infers correlation between the sequence of images. The depth information of the sequence image was calculated by the active stereo matching and the mosaic method. The merged depth information was reconstructed to the 3D shape information by wrapping and blending with image color and texture. The proposed reconstruction method could acquire strong the 3D distance information, and overcome constraint of place and distance etc, by using laser slit beam and stereo camera.

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Displacement and Velocity Dependence of Clamped Shape Metallic Dampers (꺽쇠형 강재 댐퍼의 변위 및 속도 의존성)

  • Lee, Hyun Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.2
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    • pp.62-70
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    • 2013
  • The purpose of this study is the displacement and velocity dependence evaluation of clamped shape metallic damper, which were evaluated superior in energy dissipation capacity than straight type slit damper. For this purpose, 6 metallic damper specimens are prepared and dependence test are performed. Test variables are displacement dependence and velocity dependence. According to displacement dependence test results, larger target displacement (50mm) shows lower cyclic numbers and cumulated energy dissipated area than lower target displacement (25mm). Also it shows higher strength and early failure than short target displacement. In velocity dependence evaluation, fast target velocity (60mm/sec) shows lower cyclic numbers and cumulated energy dissipated area than slow target velocity (40mm/sec). Therefore the hysteresis dependence of metallic damper were evaluated as close relation to the loading displacement and velocity conditions.

Measurement of the Three-Dimensional Flow Fields of a Gun-Type Gas Burner Using Triple Hot-Wire Probe (3중 열선 프로브를 이용한 Gun식 가스버너의 3차원 유동장 측정)

  • Kim, J.K.;Jeong, K.J.
    • Journal of Power System Engineering
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    • v.10 no.3
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    • pp.23-31
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    • 2006
  • Mean velocities and turbulent characteristics in the three-dimensional flow fields of a gun-type gas burner were measured by using triple hot-wire probe (T-probe) in order to compare them with the results already presented by X-type hot-wire probe (X-probe). Vectors obtained by the measurement of two kinds of probes in the horizontal plane and in the cross section respectively show more or less difference in magnitude each other, but comparatively similar shape in overall distribution. Axial mean velocity component along the centerline shows that the value by T-probe is about ten times smaller than that by X-probe above the range of X/R=3. Also, the axial component of turbulent intensity along the centerline appears the biggest difference between the two probes. Moreover, axial mean velocity component, axial turbulent intensity component and rotational along the Y-directional distance show a big difference between slits and swirl vanes. On the whole, the values by T-probe appear smaller than those by X-probe.

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BDM Rolling of Middle Sized H-beams from a Bloom (블룸을 이용한 중형 H 형강 BDM 압연 공정 연구)

  • Kim, J.M.;Kim, K.W.;Kim, B.M.
    • Transactions of Materials Processing
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    • v.25 no.1
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    • pp.43-48
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    • 2016
  • H-beams are generally produced by hot rolling composed of a Break Down Mill (BDM) and a Finishing Mill (FM). The goal of the current study was to develop BDM rolling of H300x300 beams from blooms slit from slabs. In order to manufacture H300x300 beams, the caliber design and the pass schedule of BDM rolling were proposed for a bloom instead of a beam blank. The proposed BDM caliber design and pass schedule were tested using FE-simulation and pilot tests. For the major shape dimensions, such as flange width, web height, web thickness, as well as BDM rolling loads, a comparative analysis between the FE-simulation and the pilot rolling tests was conducted. The results of FEM analysis and pilot rolling tests showed good consistency. Moreover, BDM rolling loads were predicted to be in the range of allowable rolling loads. It was concluded that the designed BDM rolling is suitable for implementation within current manufacturing capacity.