• 지역사회간호학회지
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• 제28권2호
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• pp.196-205
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• 2017

Purpose: Art program has been found to enhance mood such as increasing motivation, self-expression and decreasing depression in older adults. This study was conducted to investigate the effects of clay art and drawing on depression and self-expression among elderly people at a long-term care center. Methods: The research was a pre-test and post-test non-equivalent design. Sixty older patients (clay art program=28. Drawing art program=32) over the age of 65 were recruited from 2 long-term care hospitals to participate in the 5 weeks program. Each group was scheduled with 10,120-minute evaluation sessions, twice per week. Test measures were completed before and after the 5 week intervention period for all participants. The data was collected from April 27 to May 29, 2015. It was analyzed with SPSS 22.0 using chi-square, t-test and paired t-test. Results: There were no significant difference in the levels of depression (t=0.21, p=.830) and total score of self-expression (t=-0.10, p=.919) between the two groups. However, the pre-post scores of self-expression in the clay art program (t=0.22, p=.826) were improved compared to the drawing art program (t=0.80, p=.430). Conclusion: Further studies are needed to evaluate the effectiveness of clay art program for extended senior care applications.

• 한국과학교육학회지
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• 제26권1호
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• pp.9-15
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• 2006

학생들은 화학에서 입자 개념의 중요성에도 불구하고 이를 어려워한다. 이에 여러 연구자들이 이 개념에 대한 효과적인 교수 방법을 제안하였으나, 체계적인 연구는 거의 이루어지지 않았다. 따라서 이 연구에서는 학생들이 입자 개념을 학습할 때 그림 그리기와 그림 분석하기 방법을 도입한 수업의 효과를 조사하였다. 서울시 남녀 공학 중학교 1학년 세 학급을 통제 집단과 그림 그리기 집단, 그림 분석하기 집단으로 선정하여 물질의 세 가지 상태와 분자의 운동 단원에 대하여 총 8차시 동안 수업을 실시하였다. 학생들의 시각적 학습양식에 따라 개념 이해도, 학업 성취도, 과학 학습 동기에 대한 교수 방법의 효과를 조사하였다. 연구 결과, 그리기 집단과 그림 분석하기 집단의 개념 이해도, 과학 학습 동기 점수가 통제 집단에 비해 높았다. 또한 시각적 학습양식 선호 학생들의 과학학습 동기 점수가 비선호 학생들보다 높았다.

• 대한기계학회논문집A
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• 제20권7호
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• pp.2246-2256
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• 1996

To investigate the effect of material and precess variables on stamping formability of sheet materials, simulations for the cup drawing and the Yoshida buckling test were carried out using ABAQUS, commercial nonlinear finite element analysis code. The various factor effects on stamping formability of sheet materials were analyzed by the designed process according to Taguch's orthogonal array experiment. Cup drawing simulation showed that local neckling was very sensitive to plastic anisotropy parameter of sheet material and friction coefficient between sheet and tool interface. Simulations for the Yoshida buckling test have clarified that buckling behaviour of sheet material was mostly susceptible to yield stress and sheet thickness mostly. However, plastic anisotropy parameter and strain hardening coefficient affect moderately buckling behaviour of steel sheets after the buckling initiation.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.291-295
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• 2003

The occurrence of ductile fracture is the working limit of many metal forming processes. It is necessary to predict the criteria and to apply the condition in a process design. Over the years. the way for clarifying conditions have been studied and presented. However such a way needs lots of experiments and analysis. In this study, in order to determine the critical damage value of a used material Cu 4N, it was performed a tensile test and FEM analysis by using DEFORM 2D. For applying the obtained critical damage value it was also performed a upsetting test by using DEFORM 2D. The way of determining a critical damage value which is presented in this study will make possible to find easily it which is one of the working limit factor. And the way of determining a critical damage value will make possible to find in multi-pass drawing process.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.140-143
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• 2003

The drawbead is an important part in sheet metal forming for automotive part and its effect is affected by various process parameters. Therefore in this study, drawbead friction test was performed at various process parameters - panels (cold rolled and galvanized sheet steel), lubricants (having three different viscosities), bead materials(steel, iron) and surface treatment of bead (Cr plating). Circular shape bead has been used for the test. The results show that friction and drawing characteristics were mainly influenced by the nature of zinc coating, viscosity of lubricants, surface treatment of a bead and hardness of coated layer.

• 소성∙가공
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• 제16권5호통권95호
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• pp.381-385
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• 2007

In order to examine the effect of the blank holding force on the friction behavior in the sheet metal forming, a sheet metal friction tester is designed and manufactured, which can measure friction forces in various forming conditions such as lubrication, die roughness, drawing speed, radius of die corner, blank holding force, etc., and the friction tests are performed, in which friction coefficients in various blank holding forces and pulling speeds are calculated using Coulomb's friction law. The friction test reveals that friction coefficient decreases as the blank holding force, the drawing speed and lubricant viscosity increase together or individually.

• 소성∙가공
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• 제15권8호
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• pp.603-608
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• 2006

The main purpose of the present study has been placed on investigating the mechanical properties and microstructures of C-Si-Mn-V steels for cold forming manufactured by controlled rolling and cooling technology. The steels were manufactured in electric arc furnace (EAF) and casted to $160{\times}160mm$ billet. The billets were reheated in walking beam furnace and rolled to coil, the stocks were rolled by Controlled Rolling and Cooling Technology (CRCT), so rolled at low temperature by water spraying applied in rolling stage and acceleratly cooled before coiling. Rolled coils were cold drawed to the degree of 16%, 27% of area reduction respectively without heat treatment. Microstructual observation, tensile test, compression test and charpy impact tests were conducted. The mechanical properties of the steels were changed by area reduction of cold drawing and it is founded that there are optimum level of cold drawing to minimize compression stress for these steels. From the result of this study, it is conformed that $80kg_{f}/mm^{2},\;90kg_{f}/mm^{2}$ grade high strength microalloyed steel for cold forming are developed by accelerated cooling and optimum cold drawing.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.321-324
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• 2005

The main purpose of the present study has been placed on investigating the effects of controlled rolling and cooling on the microstructures and mechanical properties of C-Si-Mn-V steels for cold forming. The steels were manufactured in vacuum induction melting(VIM) furnace and casted to 1.1ton Ingots and the ingots were forged to $\Box150$ billet. The forged billets were reheated in walking beam furnace and rolled to coil, the stocks were rolled by Controlled Rolling and Cooling Technology (CRCT), so rolled at low temperature by water spraying applied in rolling stage and acceleratly cooled before coiling. Rolled coils were cold drawed to the degree of $27\%$ of area reduction without heat treatment. Microstructual observation, tensile test, compression test and charpy impact tests were conducted. The mechanical properties of the steels were changed by area reduction of cold drawing and it is founded that there are optimum level of cold drawing to minimize compression stress for these steels. From the result of this study, it is conformed that mechanical properties and microstructure of C-Si-Mn-V steels for cold forming were enhanced by accelerated cooling and founded optimum level of cold drawing.

• 소성∙가공
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• 제21권4호
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• pp.258-264
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• 2012

The forming failure of AZ31 alloy sheet during deep drawing processes was predicted by the FEM and ductile fracture criteria. Uniaxial tensile tests of round-notched specimens and FE simulations were performed to calculate the critical damage values for three ductile fracture criteria. The critical damage values for each criterion were expressed as a function of strain rate at various temperatures. In order to determine the best criterion for failure prediction, Erichsen cupping test under isothermal conditions at $250^{\circ}C$ were conducted. Based on the plastic deformation histories obtained from the FE analysis of the Erichsen cupping tests and the critical damage value curves, the initiation time and location of fracture were predicted under bi-axial tension deformation. The results indicate that the Cockcroft-Latham criterion had good agreement with the experimental data. In addition, the FE analysis combined with the criterion was applied to another deep drawing process using an irregular shaped blank and these additional results were verified with experimental tests.

• 한국정밀공학회지
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• 제23권11호
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• pp.78-84
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• 2006

The objective of this study is to design the optimal die profile that can prevent material fracture in the tube drawing process for automobile steering input shaft. First, the CDV(Critical Damage Value) of material is obtained by the compression test and FE-analysis. The occurrence of fracture is estimated by the FE-analysis considering the CDV. In order to achieve the objective of this study, optimization technique and FE-analysis are applied. FPS(Flexible Polyhedron Search) method, which is one of the non-gradient optimization techniques often used in engineering, is used to search optimal die profile. The drawing die profile is represented by Bezier-curve to generate all the possible die profile. Using FPS method and FE-analysis the optimal drawing die profile is determined. To verify tile effectiveness of the redesigned optimal die, the tube drawing experiment is performed. In the experimental result, it is possible to produce sound product without material fracture using the redesigned optimal die.