• Title/Summary/Keyword: draw

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Efficient modeling of die-face shapes for stamping automobile outer panels (차체 판넬의 가공 제작을 위한 금형형상의 효율적 모델링)

  • 박종천;이건우;전기찬
    • Journal of the korean Society of Automotive Engineers
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    • v.15 no.3
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    • pp.96-110
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    • 1993
  • A procedure has been developed so that a die-face for stamping automobile outer panels can be design and modelled efficiently. The procedure is composed of four parts each of which corresponds to modeling major components of a die-face, i.e. tipped product, blankholder, draw beads, and step draw. The modeling techniques developed specifically for die-face design enable a designer to generate the shape of a die-face quickly with the minimum input, and the resulting models can be used in FEM analysis and NC tool path generation. This will lead to the reductions in lead time and manhours required for the design and manufacture of the stamping dies.

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Deterioration of Polyethylene Films Induced by Partial Discharge and Variations Observed in Mechanical Properties (Polyethylene film의 부분방전열화와 역학적 특성)

  • ;Shigeru Yamamot
    • Journal of the Korean Society of Safety
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    • v.4 no.1
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    • pp.5-14
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    • 1989
  • Deterioration induced by partial discharge was investigated for low-density polyethylene samples. Under an electrical field, a cold-drawn PE film was stretched perpendicularly to the direction of the original drawing. The starting voltage of the discharge shows a minimum at the draw ratio of 1.2 to 1.8. Around the same draw ratio, the elastic modulus and mechanical loss factor (tan S) of the sample exhibit a minimum and a maximum, respectively. According to the X-ray analysis, the size itf microcrystals decreases with increasing draw ratios. Reorientation of the ru01ecular chains was observed above a draw ratio of 1.5 by the IR method.

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A Forming and Springback Analysis for the U-channel Draw (U-channel Draw 성형 및 스프링백 해석)

  • Choi, E.K.;Park, K.S.;Oh, H.K.;Yu, D.H.;Lee, S.W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.465-468
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    • 2008
  • In this paper, ABAQUS, one of the implicit finite element codes, is used to analyze the U-channel Draw benchmark problem of NUMISHEET 2005. Forming and springback stages have been done consecutively to compare their results with the experimental ones. The main measures for comparing are the side wall curl and angle. The result by numerical analysis are shown generally to be correspondent with the experimental results that the max. error is confined under about 10%.

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Synthesis of New Draw Solute Based on Polyethyleneimine for Forward Osmosis (정삼투를 위한 Polyethyleneimine 기반 유도용질 제조)

  • Lee, Hye-Jin;Choi, Jin-Il;Kwon, Sei;Kim, In-Chul
    • Membrane Journal
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    • v.28 no.4
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    • pp.286-295
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    • 2018
  • A novel multi-valent salt based on polyethyleneimine having molecular weight of 800 (PEI 800) has been synthesized and characterized as forward osmosis draws solute. A reaction intermediate was synthesized by the neutralization reaction of polyethyleneimine and methyl acrylate, and was hydrolyzed with potassium hydroxide to synthesize a water soluble carboxylic acid (potassium salt) polyethyleneimine. NMR spectrometry, viscometry measurements and osmometry measurements was performed to characterize the draw solute. Forward osmosis experiments were done to know whether the solute could be used as a draw solute or not. The result shows comparable water flux and lower reverse salt flux compared with NaCl as a draw solute. We have also demonstrated recycling of the draw solute in the FO-NF integrated process.

Synthesis of n-nitrilotris(methylene) Phosphonic Acid Potassium Salt as a Draw Solute in Forward Osmosis Process (정삼투 분리막 공정 적용을 위한 n-nitrilotris(methylene) Phosphonic Acid Potassium Salt 유도용질의 합성)

  • Lee, Hye-Jin;Choi, Jin-Il;Kwon, Sei;Kim, In-Chul
    • Membrane Journal
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    • v.28 no.5
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    • pp.368-377
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    • 2018
  • The n-nitrilotris(methylene) phosphonic acid (NTPA) potassium salt was synthesized as a draw solute for forward osmosis. NTPA-4K, NTPA-5K and NTPA-6K were synthesized by varying the content of KOH added to NTPA and confirmed by $^1H$-NMR and $^{13}C$-NMR. The osmotic pressure, viscosity, water flux and reverse salt flux were measured to characterize the draw solute. In the forward osmosis process when distilled water was used as a feed solution and 0.5 M of NTPA-4K, NTPA-5K and NTPA-6K were used as a draw solution, the water flux was 35.8, 38.8 and 42.2 LMH, the reverse salt flux was 5.4, 6.9 and 7.4 gMH, respectively. It was confirmed that the water flux was lower than the conventional NaCl draw solution, but the reverse salt flux was much lower. In order to recover the diluted draw solution, nanofiltration was conducted. The results showed that the draw solute could be retained by above 90%.

A Web-based Simulation Environment based on the Client/Server Architecture for Distance Education: SimDraw (원격교육을 위한 클라이언트/서버구조의 웹 기반 시뮬레이션 환경 : SimDraw)

  • 서현곤;사공봉;김기형
    • Journal of KIISE:Software and Applications
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    • v.30 no.11
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    • pp.1080-1091
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    • 2003
  • Recently, the distance education has been rapidly proliferated with the rapid growth of the Internet and high speed networks. There has been relatively much research with regard to online lecture (teaching and studying) tools for the distance education, compared to the virtual laboratory tools (for self-study and experiments). In this paper, we design and implement a web-based simulation tool, named as SimDraw, for the virtual laboratory in the distance education. To apply the web-based simulation technology into the distance education, some requirements should be met; firstly, the user interface of the simulation should be very easy for students. Secondly, the simulation should be very portable to be run on various computer systems of remote students. Finally, the simulation program on remote computers should be very thin so that students can easily install the program onto their computers. To meet these requirements, SimDraw adopts the client/server architecture; the client program contains only model development and animation functions so that no installation of a client program onto student's system is required, and it can be implemented by a Java applet in Web browsers. The server program supports client programs by offering the functions such as remote compiling, model storing, library management, and user management. For the evaluation of SimDraw, we show the simulation process using the example experimentation of the RIP(Routing Information Protocol) Internet routing protocol.

Effects of Draw Ratio and Additive CaCO3 Content on Properties of High-Performance PE Monofilament (연신비와 첨가제 CaCO3가 PE 모노필라멘트의 물성에 미치는 영향)

  • Park, Eun-Jeong;Kim, Il-Jin;Lee, Dong-Jin;Kim, Jung-Soo;Lee, Young-Hee
    • Fashion & Textile Research Journal
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    • v.23 no.2
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    • pp.290-296
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    • 2021
  • The effect of draw ratio (8, 10, 12, 14 times) and additive CaCO3 content (0, 0.5, 1.0, 1.5, 2.0, and 3.0 wt%) on the properties of high-performance PE monofilament was investigated in this study. As the draw ratio increased (8-14 times), the melting enthalpy (ΔHf), crystallinity, specific gravity, and tensile strength increased significantly. However, the draw ratio had little effect on the melting temperature (Tm) and crystallization temperature (Tc). The seawater fastness (stain and fade) of the hydrophobic PE monofilament prepared in this study showed an excellent grade of 4-5 in all draw ratios. To investigate the effect of the additive CaCO3 content on the properties of high-performance PE monofilament, the draw ratio was fixed at 14 times. It was found that the tensile strength of the PE monofilament sample containing 0.5 wt% of CaCO3 was much greater compared to the sample without CaCO3, but the elongation of the sample containing 0.5 wt% of CaCO3 was much less than the sample with 0 wt% CaCO3. However, in the case of the sample containing more than 0.5 wt% CaCO3, the tensile strength slightly decreased and the elongation slightly increased as the CaCO3 content increased. The seawater fastness (stain and fade) of the hydrophobic PE monofilament showed excellent grades of 4-5, regardless of the amount of additives. From the above results, it was found that the maximum draw ratio of 14 times with an additive of 0.5 wt% CaCO3 are the optimal conditions for manufacturing high-performance marine fusion materials with various fineness (denier) with high strength and low elongation.

The Effect of Abdominal Draw-in Maneuver with Leg Movements on Transversus Abdominis Thickness and Trunk Control in Stroke Patients (다리 움직임을 동반한 복부 드로우-인 기법이 뇌졸중 환자의 배가로근 두께와 몸통 조절에 미치는 영향)

  • Kang, Jeong-Il;Moon, Young-Jun;Jeong, Dae‐Keun
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.8
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    • pp.287-294
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    • 2020
  • The purpose of this study was, base on the observation that the leg movement has effect on muscles around trunk, to provide clinical fundamental data to develop effective abdominal draw-in technique by investigating the effect of abdominal draw-in exercise accompanying leg movement on the thickness of transversus abdominis muscle and trunk control ability in patients with stroke. The subjects were assigned randomly to experimental group I (n=9) on which the abdominal draw-in technique is applied and experimental group II (n=9) on which the abdominal draw-in technique accompanying leg movement is applied. The thickness of transversus abdominis muscle in the affected side and the trunk control ability were measured before and after treatment using ultrasonography and trunk impairment scale. A session of 30 minutes per day were performed four days a week for four weeks and the measured outcomes were analyzed. The in-group comparison showed significant difference both thickness of transversus abdominis muscle during abdominal draw-in technique application (p<0.01) and trunk control ability (p<0.001) between before and after treatment. The significant difference between two groups were observed only in trunk control ability (p<0.05). It was concluded that the abdominal draw-in technique accompanying leg movement is an intervention that has positive effect not only on transversus abdominis muscle but also on tunk control ability by inducing more efficient contraction reaction in muscles around trunk through autonomic pelvic movement caused by leg movement.