• Title/Summary/Keyword: Sharp shape

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A Study on the Sleeve Fitness According to Characteristics of Arm Types (팔 유형 특성에 따른 소매 적합성 연구)

  • 이정란
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.2
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    • pp.219-228
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    • 2003
  • The purpose of this study were to examine the characteristics of arm types proposed in the previous study and to present sleeve patterns according size and shape of 4 arm types. 31 direct and indirect items were measured. The subjects for this study were 132 females of twenties. The results were as follows. 1. All of the direct measurements showed significant difference by the arm types. especially at the front armhole part. Such a.: the items of arm gradients, armhole sizes belong to the indirect measurements made clear difference also. 2. By the discriminant analysis, 9 items including underarm length, front armhole girth, upper arm girth, degree of elbow point-wrist point discriminated arm type by the hit ratio of 90.4% Item related to shape of arm rather than size made a sharp distinction. 3. Through the examination of existing patterns and wearing tests on the subjects among 4 groups, sleeve patterns classified by the arm type were suggested.

Design of Cold Heading Process of a Screw for Storage Parts (저장매체용 스크류의 냉간 헤딩 공정 설계에 대한 연구)

  • Seo, W.S.;Min, B.W.;Park, K.;Ra, S.W.;Lee, S.H.;Kim, J.H.;Kim, J.B.
    • Transactions of Materials Processing
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    • v.20 no.1
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    • pp.48-53
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    • 2011
  • Fasteners are used to join the various electronic products and machines. So, the quality and reliability of the fastener are strongly requested. In this study, the analyses of the multi-stage cold forging of TORX screws for storage parts are carried out. In manufacturing of TORX screws, crack and folding defects are observed. Therefore, the analysis is focused on the prediction of the defects. Based on the analysis results, the upper die and process conditions are redesigned to reduce the defects. The upper die shape for preform forming is redesigned to prevent folding and sharp shape change. The Cockroft-Latham damage criterion is introduced to predict the crack initiation. Analysis results shows that the maximum Cockroft-Latham damage value is decreased by 40% in the forming using the modified upper die.

Improvement in Dimensional Accuracy of Transfer-type for Variable Lamination Manufacturing using Expandable Polystyrene Foam (VLM-ST의 형상정밀도 향상에 관한 연구)

  • 최홍석;이상호;안동규;양동열;문영복;박두섭;채희창
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.1047-1050
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    • 1997
  • Rapid Prototyping(RP) is an efficient method for rapid design verification and trial manufacturing. In order to improve their unique characteristics according to the working principles. Variable Lamination Manufacturing process and corresponding CAD/CAM system is developed. The objective of this study is to improve dimensional accuracy of VLM-ST process, and it can be done by offset for cutting error correction, cutting path correction for sharp edge and reference shape generation. To verify the proposed algorithms, they applied to three-dimensional shapes, such as spanner and mechanical part.

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Fabrication of Tungsten Carbide Microshaft Using Electrochemical Machining (전해 가공을 이용한 텅스텐 카바이드 미세축 제작)

  • Kang, Myung-Ju;Oh, Young-Tak;Chu, chong-Nam
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.80-87
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    • 2002
  • Tungsten carbide microshaft is used as micro-punch, electrode of MEDM (micro-electro-discharge machining), and micro-tool because it has high hardness and high rigidity. In this study, the tungsten carbide microshaft was fabricated using electrochemical machining. Concentration of material removal at the sharp edge and metal corrosion layer affect the shape of the microshaft. Control of microshaft shape was possib1e through conditioning the machining voltage and electrolyte concentration. By applying periodic voltage, material removal rate increased and surface roughness improved. The fabricated microshaft in $H_2 SO_4$ electrolyte maintained sharper end edge and better surface finish than those fabricated by other electrolytes.

Korean Traffic Speed Limit Sign Recognition in Three Stages using Morphological Operations (형태학적 방법을 사용한 세 단계 속도 표지판 인식법)

  • Chirakkal, Vinjohn;Kim, SangKi;Kim, Chisung;Han, Dong Seog
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2015.07a
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    • pp.516-517
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    • 2015
  • The automatic traffic sign detection and recognition has been one of the highly researched and an important component of advanced driver assistance systems (ADAS). They are designed especially to warn the drivers of imminent dangers such as sharp curves, under construction zone, etc. This paper presents a traffic sign recognition (TSR) system using morphological operations and multiple descriptors. The TSR system is realized in three stages: segmentation, shape classification and recognition stage. The system is designed to attain maximum accuracy at the segmentation stage with the inclusion of morphological operations and boost the computation time at the shape classification stage using MB-LBP descriptor. The proposed system is tested on the German traffic sign recognition benchmark (GTSRB) and on Korean traffic sign dataset.

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Distortion of the Bottom Surface in Micro Cavity Machining Using MEDM (미세 캐비티 방전 가공에서 바닥면 형상 왜곡)

  • 임종훈;류시형;제성욱;주종남
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.12
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    • pp.191-197
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    • 2003
  • As mechanical components are miniaturized, the demand on micro die and mold is increasing. Micro mechanical components usually have high hardness and good conductivity. So micro electrical discharge machining (MEDM) is an effective way to machine those components. In micro cavity fabrication using MEDM, it is observed that the bottom surface of cavity is distorted. Electric charges tend to be concentrated at the sharp edge. At the center of the bottom surface, debris can not be drawn off easily. These two phenomena make the bottom surface of the electrode and workpiece distort. As machining depth increases, the distorted shape of electrode approaches hemisphere. This process is affected by capacitance and the size of electrode. By using a smaller electrode than the desired cavity size and appropriate tool movement, bottom shape distortion can be prevented.

A Study on Deformation Behaviors of Al 6061, 7075 Tube at Different Heat Treatments for Warm Hydroforming (온간액압성형공정 적용을 위한 알루미늄 6061, 7075 튜브의 열처리조건에 따른 변형특성연구)

  • Yi, Hyae-Kyung;Moon, Young Hoon
    • Journal of the Korean Society for Heat Treatment
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    • v.20 no.1
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    • pp.1-10
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    • 2007
  • The deformation behaviors of full annealed and T6 treated 6061, 7075 aluminum tubes are investigated at various temperature performing uniaxial tensile test. Full annealed Al 6061 and Al7075 tubes, and T6 treated Al7075 tube don't show sharp local necking with an elongation of 50% at $300^{\circ}C$. So it is expected that influenced by elevated tempterature. At $300^{\circ}C$ and strain rate of 0.001/s, many micro-cracks are observed in T6 treated Al 6061 tube, which is believed to be responsible for the decrease of total elongation.

Distortion of the Bottom Surface in Micro Cavity Machining Using MEDM

  • Lim Jong Hoon;Je Sung Uk;Ryu Shi Hyoung;Chu Chong Nam
    • International Journal of Precision Engineering and Manufacturing
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    • v.6 no.4
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    • pp.44-48
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    • 2005
  • As mechanical components are miniaturized, the demands on micro die/mold are increasing. Micro mechanical components usually have high hardness and good conductivity. Micro electrical discharge machining (MEDM) can thus be an effective way to machine those components. In micro cavity fabrication using MEDM, it is observed that the bottom surface of the cavity is distorted. Electric charges tend to be concentrated at the sharp edge, and debris cannot be drawn off easily at the center of the bottom surface. These two phenomena make the bottom surface of electrode and workpiece distort. As machining depth increases, the distorted shape of the electrode approaches hemisphere. This process is affected by both capacitance and the size of electrode. By using a smaller electrode than the desired cavity size and appropriate tool movement, bottom shape distortion can be prevented.

An Estimation of Discharge Coefficients with the Variations of Side Weir Shape (횡월류위어의 형상에 따른 유량자수 추정)

  • Song, Jai-Woo;Park, Sung-Sik;Kim, Ji-Ho
    • Journal of Korea Water Resources Association
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    • v.40 no.1 s.174
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    • pp.51-62
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    • 2007
  • To estimate more accurately the outflow over a sharp crested side weir, it is necessary to analyze the flow characteristics over side weir and to estimate the discharge coefficient in the weir equation. The purpose of this study is to estimate the discharge coefficients of sharp crested rectangular and triangular side weirs by means of hydraulic model experiments with the variations of upstream Froude number in the main channel and length and apex angle. Experimental results show that the discharge coefficients depend on the shape and geometric conditions of side weir as well as the upstream Froude number in the main channel. Through the multiple regression analysis, formulas of discharge coefficient for rectangular and triangular types are proposed and its applicability is confirmed by comparing estimated and measured discharges over side weirs.

A Study on Make-up Expression of Horror Character in Horror Movie (공포영화에 나타난 공포 캐릭터의 분장표현 연구)

  • Kim, Yu-Kyoung;Cho, Ji-Na
    • Journal of Fashion Business
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    • v.12 no.5
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    • pp.77-93
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    • 2008
  • The purpose of the study was to examine make-up expression elements of horror characters as an evil spirit, a vampire, a zombie, a monster and a psycho murderer through make-up, focused on horror movies of the United States after1960s. First, an evil spirit was expressed that the pupil grew dim without a focus and the skin was torn by going bad and rot completely. Also, it was expressed that its teeth was changed to pointed canine teeth as a wild beast and its pale and bloodless face showed blood vessels clearly. To express its bloodless and pale skin, air brush was swept into the skin over several times. Its canine tooth was made acryl powder into its shape and was harden to make its shape smooth. Also, it was colored to show people like the real thing. Second, a vampire was expressed by make-up elements as long nails, a sharp canine tooth, a pale skin with a blood vessel and dead eyes. Its rough skin and long nails were manufactured with latex foam, which was colored like the skin. Third, a monster image as a werewolf was expressed by make-up elements as fur, sharp teeth, changed nails and toenails, a rough skin and a face changed to a wolf. Rubber mask and rubber body suit were manufactured as a make-up of special character and so all its body was changed. Fourth, a psycho murderer and body-deformed man were expressed by make-up elements as a distorted mask, swelled-up and deformed skull and face form, terribly deformed body, discolored and hang down skin and teeth with an indeterminate form. Its body and face were manufactured by the foam latex technology according to make-up design as a make-up of special character.