• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.127-131
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• 2006

There are being a lot of studies for achievement of high speed Dehydration, high-strength and Lightweight of washing machine in the latest washing machine business. It is essential that Press-joining Strength of Spin Drum Seaming division is improved .to attain that target. Generally, we are using Mechanical press-joining by Seaming and T.I.G (Tungsten Inert Gas) welding among part joint method. Mechanical press-joining method that is mainly using for Stainless Steel (STS430) Drum have lots of merit that consumption of energy is low more than welding and production costs cut down and generation of the corrosion is solved by removing weld zone defect and materials having different properties are enable to join without special equipment. But, it is difficult to realize joint strength required at high speed operation because joint strength of mechanical press-joining method is low remarkably in comparison with welding. Also, there are a lot of analysis difficulties and very limited research is under way due to the dynamic factor such as multistage plastic working, elastic recovery, residual stress etc. The results of this study show optimal joining condition for mechanical press-joining by performing lots of tensile joining strength test with various specimen under multi-change of important design factor such as seaming width, bead area and bead depth etc.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1511-1516
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• 2007

Because Seaming process of MPJ (Mechanical Press Joining) has various design factors such as thickness, bending radius, seaming width, caulking press width and the dynamic factor such as multistage plastic working, elastic recovery, residual stress, the optimum conditions can't be easily determined. Using a design of experiment based on the FEM, which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor during drum MPJ and proposed optimum condition using center composition method among response surface derived from regression equation of simulation-based DOE.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.99-107
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• 2008

There are being a lot of studies for achievement of high speed Dehydration, high-strength and Lightweight of washing machine in the latest washing machine business. It is essential that strength of mechanical press-Joining (MPJ) for spin drum is improved to attain that target. MPJ of spin drum is composed of seaming and caulking process. Because Seaming process of MPJ has various design factors such as thickness, bending radius, seaming width, caulking press width and the dynamic factor such as multistage plastic working, elastic recovery, residual stress, the optimum conditions can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor during drum MPJ and proposed optimum condition using center composition method among response surface derived from regression equation of simulation-based DOE.

• Journal of the Korean Magnetics Society
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• v.17 no.1
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• pp.38-42
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• 2007

The crystallographic and magnetic properties of $KFeO_2$ powder prepared by ball-mill method, have been studied by x-ray diffraction(XRD), $M\"{o}ssbauer$ spectroscopy, and vibrating sample magnetometer(VSM) measurements. The crystal structure of $KFeO_2$ powder at room temperature is determined to be an orthorhombic structure of Pbca with its lattice constants $a_0=5.557{\AA},\;b_0=11.227{\AA},\;c_0=15.890{\AA}$ by Rietveld refinement. $M\"{o}ssbauer$ spectra of $KFeO_2$ were taken at various temperatures ranging from 4.2 to 818 K. The magnetic hyperfine field and isomer shift value at 4.2 K and RT were 519 kOe, 489 kOe and 0.19 mm/s, 0.05 mm/s respectively. The average hyperfine field $H_{hf}(T)$ of the $KFeO_2$ shows a temperature dependence of $[H_{hf}(T)-H_{hf}(0)]/H_{hf}(0)=-0.36(T/T_N)^{5/2}$ for $T/T_N$<0.7, indicative of spin-wave excitation.