• Title/Summary/Keyword: Forming Process

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Analysis of CAD Design and Physical Properties of Double-raschel Spacer Fabric (더블라셀 소재의 CAD에 의한 표현과 물성연구)

  • Choi, Kyoungme;Kim, Jongjun
    • Journal of Fashion Business
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    • v.23 no.1
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    • pp.37-48
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    • 2019
  • WKSF (Warp-knitted spacer fabrics) knitted using a double Raschel machine is the three-dimensional knit that has vertically connected separate layers in loop structures. Because of its unique structure, the fabric is light, compressible and breathable. Owing to the high production speed, the use of the fabric is increasing in various areas. The purpose of this study is to establish the design process in the utilization of WKSF program and analyze the difference between WKSF and Neoprene as garment materials.. The study on the design related to WKSF has rarely been carried out because of the complexity of WKSF structure and the difficulties encountered in analyzing the structure and thread. Therefore, checking beforehand the simulation results similar to a final knit using the CAD program for WKSF can only enhance the efficiency of the design for the light knits. The conclusion drawn after designing the light knits using the CAD program and analyzing the pros and cons of WKSF through the various property evaluation techniques is as follows. The tension characteristic analysis results indicated that Neoprene specimen has the elastic transformation and resilience, thus behaving like an elastic product such as rubber. By contrast, in the event that clothing and fashion accessories are designed with WKSF, these products are kept in a boxy style fit so that the fabric can be applied flexibly to a curvy body line. In addition, WKSF is good in forming noticeably around a curvy body, because its resistance shear deformation is lower than that of Neoprene.

Fabrication of Micro-Porous Membrane via a Solution Spreading Phase Inversion Method (용액 퍼짐 상분리법을 통한 마이크로 기공 분리막 제조)

  • Choi, Ook;Park, Chul Ho
    • Membrane Journal
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    • v.29 no.2
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    • pp.105-110
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    • 2019
  • Porous membranes are widely used in industry for removing particulate matter. Unlike conventional porous membrane fabrication methods, the solution spreading phase separation method can form pores very simply. The first step is to wet the mesh with the support layer, then to let the polysulfone solution flow into a solvent without water. The solvent is readily vaporized and the polysulfone is made into a thin film. When the polysulfone solution is mixed with water to form pores, the pore size can be adjusted according to the concentration ratio of the polysulfone solution. The thickness of the membrane is easily controlled by the concentration of the solution. The porous separator has the formation of meshes intact and is very useful for forming a three-dimensional structure. The solution spreading phase separation method proposed in this study is characterized by its high cost competitiveness compared with conventional membranes due to its low production cost and easy process control.

Fabrication and Chracteristics of Cutting Cell with Various Laser Conditions (다양한 레이저 조건에 따른 컷팅셀 제작 및 특성 분석)

  • Park, Jeong Eun;Kim, Dong Sik;Choi, Won Seok;Jang, Jae Joon;Lim, Dong gun
    • Journal of the Korean Solar Energy Society
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    • v.39 no.3
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    • pp.9-17
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    • 2019
  • Laser cutting cell of solar cells can achieve high voltage and efficiency through more array than conventional 6 inch cell compared to same area. In this study, we fabricated c-Si cutting cell with various lasers and laser conditions such as power, speed, and number of times. In the case of picosecond laser, excellent surface characteristics were obtained due to small surface defects and low thermal damage at the output of 20W and the speed of 100 mm/s. However, it is not possible to fabricate a cutting cell having good characteristics due to nonuniform cutting inside the wafer when the processing for forming a cutting cell is not sufficiently performed. For nanosecond lasers, the best wafer characteristics were obtained for fabrication of excellent cutting cells at a frequency of 500 kHz and a laser speed of 100 mm/s. However, the nanosecond laser has not been processed sufficiently in the condition of a number of times. As a result, it was confirmed that the wafer thickness was cut by $63{\mu}m$ of the cell thickness of $170{\mu}m$ in the condition of five times of laser process. It was found that more than 30% of the wafer thickness had to be processed to fabricate the cutting cell. After cutting the 6-inch cell having the voltage of 0.65 V, we obtained the voltage of about 0.63 V.

A Narrative Inquiry Regarding the Growth, Overcoming Hardship, and Social Adjustment of Student Athletes from Broken Families (결손가정에서 성장한 학생선수들의 성장과정, 역경극복 및 사회적응에 대한 내러티브 탐구)

  • Shin, Song-Hwi;Kim, Seung-Yong
    • Journal of the Korea Convergence Society
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    • v.10 no.5
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    • pp.267-278
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    • 2019
  • The objective of the current study was to engage in an in-depth discussion and analysis about the process of overcoming hardships in students that play varsity sports as student athletes and who grew up under incomplete family structures, To achieve this end, the current study conducts a narrative inquiry into the subjects, which found the following: First, in terms of improvement and expansion of interpersonal relationships, the student athletes were able to change their personalities to be more confident and active in their daily routines. Second, in forming positive emotions through playing sports, the student athletes were able to actively search for ways to overcome difficult situations and self-regulated their emotions. Third, in relation to improvement of problem-solving skills, the student athletes were able to find the most effective ways to overcome hardships caused by their broken family situations, in addition to exhibiting advanced problem-solving skills that enabled them to find courses that are most adequate for solving future problems.

GPU-based modeling and rendering techniques of 3D clouds using procedural functions (절차적 함수를 이용한 GPU기반 실시간 3D구름 모델링 및 렌더링 기법)

  • Sung, Mankyu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.4
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    • pp.416-422
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    • 2019
  • This paper proposes a GPU-based modeling and rendering of 3D clouds using procedural functions. The formation of clouds is based on modified noise function made with fbm(Fractional Brownian Motion). Those noise values turn into densities of droplets of liquid water, which is a critical parameter for forming the three different types of clouds. At the rendering stage, the algorithm applies the ray marching technique to decide the colors of cloud using density values obtained from the noise function. In this process, all lighting attenuation and scattering are calculated by physically based manner. Once we have the clouds, they are blended on the sky, which is also rendered physically. We also make the clouds moving in the sky by the wind force. All algorithms are implemented and tested on GPU using GLSL.

Atmospheric Pressure Plasma Etching Technology for Forming Circular Holes in Perovskite Semiconductor Materials (페로브스카이트 반도체 물질에 원형 패턴을 형성하기 위한 상압플라즈마 식각 기술)

  • Kim, Moojin
    • Journal of Convergence for Information Technology
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    • v.11 no.2
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    • pp.10-15
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    • 2021
  • In this paper, we formed perovskite (CH3NH3PbI3) thin films on glass with wet coating methods, and used various analytical techniques to discuss film thickness, surface roughness, crystallinity, composition, and optical property. The coated semiconductor material has no defects and is uniform, the surface roughness value is very small, and a high absorption rate has been observed in the visible light area. Next, in order to implement the hole shape in the organic-inorganic layer, Samples in the order of a metal mask with holes at regular intervals, a glass coated with a perovskite material, and a magnet were etched with atmospheric pressure plasma equipment. The shape of the hole formed in the perovskite material was analyzed by changing the time. It can be seen that more etching is performed as the time increases. The sample with the longest processing time was examined in more detail, and it was classified into 7 regions by the difference according to the location of the plasma.

Developing Vignettes on Scientists' Research Cases and Exploring Their Effectiveness (과학자의 연구 사례에 관한 비네트 개발 및 효과 탐색)

  • Park, Jaeyong;Lee, Kiyoung
    • Journal of Korean Elementary Science Education
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    • v.40 no.1
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    • pp.81-99
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    • 2021
  • The purpose of this study is to develop scientist vignettes and to explore their effects to change students' perceptions of scientists, scientific attitudes, and the nature of science. The scientist vignettes developed in this study include research cases on seven scientists, including British zoologist Jane Goodall. Each vignette consists of 4 to 6 pages in consideration of the reading level of elementary school students, and contains illustrations describing the main contents of the text. In addition, scientist vignettes contain descriptions on terms and text boxes explaining the higher concepts, and each vignette contains questions that students can think deeply based on the story of the scientist. To verify the educational effectiveness of scientist vignettes, we investigated changes in their perceptions of scientists, scientific attitudes, and the nature of science in 564 elementary school students. We conducted group interviews with four elementary school teachers. As a result of conducting pre-test and post-test using a narrative questionnaire consisting of 6 questions, students became more sophisticated in the understanding of the science and the characteristics of scientists after experiencing scientist vignettes and their understanding the nature of science changed into a more modern epistemological perspective. Also, in a group interview with teachers, teachers assessed that scientist vignettes would positively affect the understanding of science process skills and the nature of science, and forming a scientific attitude, especially in increasing understanding of the nature of science. We discussed ways to effectively utilize scientist vignettes in elementary school science education based on these result.

Thermal stability, magnetic and magnetocaloric properties of Gd55Co35M10 (M = Si, Zr and Nb) melt-spun ribbons

  • Jiao, D.L.;Zhong, X.C.;Zhang, H.;Qiu, W.Q.;Liu, Z.W.;Ramanujan, R.V.
    • Current Applied Physics
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    • v.18 no.12
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    • pp.1523-1527
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    • 2018
  • The thermal stability, magnetic and magnetocaloric properties of $Gd_{55}Co_{35}M_{10}$ (M = Si, Zr and Nb) melts-pun ribbons were studied. The relatively high reduced glass transition temperature ($T_{x1}/T_m$ > 0.60) and low melting point ($T_m$) resulted in excellent glass forming ability (GFA). The Curie temperatures ($T_C$) of melt-spun amorphous ribbons $Gd_{55}Co_{35}M_{10}$ for M = Si, Zr and Nb were 166, 148 and 173 K, respectively. For a magnetic field change of 2 T, the values of maximum magnetic entropy change $(-{\Delta}S_M)^{max}$ for $Gd_{55}Co_{35}Si_{10}$, $Gd_{55}Co_{35}Zr_{10}$ and $Gd_{55}Co_{35}Nb_{10}$ were found to be 2.86, 4.28 and $4.05J\;kg^{-1}K^{-1}$, while the refrigeration capacity (RC) values were 154, 274 and $174J\;kg^{-1}$, respectively. The $RC_{FWHM}$ values of amorphous alloys $Gd_{55}Co_{35}M_{10}$ (M = Si, Zr and Nb) are comparable to or larger than that of $LaFe_{11.6}Si_{1.4}$ crystalline alloy. Large values of $(-{\Delta}S_M)^{max}$ and RC along with good thermal stability make $Gd_{55}Co_{35}M_{10}$ (M = Si, Zr and Nb) amorphous alloys be potential materials for magnetic cooling operating in a wide temperature range from 150 to 175 K, e.g., as part of a gas liquefaction process.

A Study on Derivation of Contact Heat Transfer Coefficient Between Die and Aluminum Billet in High Temperature Compression Process (고온 압축 공정에서 금형과 알루미늄 빌렛의 접촉 열전달 계수 도출에 관한 연구)

  • Jeon, H.W.;Suh, C.H.;Oh, S.G.;Kwon, T.H.;Kang, G.P.;Yook, H.S.
    • Transactions of Materials Processing
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    • v.30 no.3
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    • pp.142-148
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    • 2021
  • In hot forging analysis, the interfacial heat transfer coefficient (IHTC) is a very important factor defining the heat flow between the die and the material. In particular, in the hot forging analysis of aluminum 6xxx series alloy, which are used in automobile parts, differences in load and microstructure occur due to changes in surface temperature according to the IHTC. This IHTC is not a constant value but changes depends on pressure. This study derived the IHTC under low load using aluminum 6082 alloy. An experiment was performed by fabricating a compression die, and a heat transfer analysis was performed based on the experimental data. The heat transfer analysis used DEFORM-2D, a commercial finite element analysis program. To derive the IHTC, heat transfer analysis was performed for the IHTC in the range of 10 to 50 kW/m2℃ at intervals of 10kW/m2℃. The heat transfer analysis results according to the IHTC and the actual experimental values were compared to derive the IHTC of the aluminum 6082 alloy under low load.

Job Retention Process among Working People with Mental Illness: A Grounded Theory Approach (취업 정신장애인의 직업 유지 과정: 근거이론적용)

  • Hyun, Myung Sun;Nam, Kyoung A;Kim, Hyunlye;Kim, Su Young
    • Journal of Korean Academy of Nursing
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    • v.51 no.3
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    • pp.320-333
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    • 2021
  • Purpose: The study was conducted to explore the experiences of job retention among working people with mental illness. Methods: The participants were members with mental illness at the S Community Mental Health Center in Gyeonggi Province and who had been working for more than six months. The data were collected through in-depth interviews with 11 participants between June 27 and August 20, 2018. The data were analyzed through Corbin and Strauss's grounded theory method. Results: The core category was struggling to take root in the community as a productive member. The core phenomenon was the desire to be a productive person, and the causal condition was the willingness to change for a purposeful life. The action and interaction strategies included maintaining regular living patterns, maintaining medication, developing one's tips for self-management, and self-approval. The intervening conditions were difficulties in forming social relationships, presence of symptoms, social resources, and acceptance of one's mental illness. The consequences were restoration of family relationships, healthy pleasure through work, social inclusion, development of self-worth, and transition to an independent person. Conclusion: Working people with mental illness are struggling to take root in the community as a productive member. This study suggests that a holistic understanding of the job retention experience among people with mental illness is required. The findings will provide the basis for developing interventions that can improve job retention among working people with mental illness.