• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.03b
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• pp.138-144
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• 1996

In square die extrusion, flow guide and ide land play important roles for controlling the metal flow in die design. In the present work, the flow guide and the die land are considered for the die construction. Based on ALE description , rigid-viscoplastic finite element analysid is carried out to assess the effects of process and die design parameters. The thermal state affects greatly the product quality in hot extrusion. in the present work, the temperature distribution is also analyzed in theframwork of rigid-viscoplastic finite element computation. As a computational example, hot square die extrusion with flow guide and die land has been analyzed for the profile of a H section.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.641-645
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• 2002

In case of aluminum-cased battery, The ratio of height and base of square is generally above the ten times, square-shaped and problem of non-axis symmetry. It is typical model to set up the analysis method of finite element. The reliable analysis of finite element method is suggested, which is used to investigate the possibility that multi-stage deep drawing and ironing used currently is replaced by backward impact extrusion favorable in the respect of cost production and productivity. The influence of parameter was analyzed and compared, which was considered to analyze the process of large deformation plasticity such as extrusion. Die and billet was made as the same shape of finite element model. The results of experiment show good forming without the rupture and wrinkles with the optimum velocity 100mm/sec obtained by analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.71-74
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• 1998

In this Paper, we investigate the electrical properties of ultra-thin(70${\AA}$) nitrided(NO) and reoxidized nitrided oxide(ONO) film that ale considered to be premising candidates for replacing conventional silicon dioxide film in ULSI level integration. we studied I$\sub$g/-V$\sub$g/ characteristics to know the effect of nitridation and reoxidation on the current conduction, leakage current time-dependent dielectric breakdown(TDDB) to evaluate charge-to-breakdown(Q$\sub$bd/), and the effect of stress temperature(25, 50, 75, 100$^{\circ}C$) and compared to those with thermal gate oxide(SiO$_2$) of identical thickness. From the measurement results, we find that reoxidized nitrided oxide(ONO) film shows superior dielectric characteristics, leakage current, and breakdown-to-charge(Qbd) performance over the NO film, while maintaining a similar electric field dependence compared to NO layer. Besides, ONO film has strong resistance against variation in temperature.

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.144-147
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• 1985

In electricity industry, the improvement of load factor by flattening of load has been considered to be more important than any other tasks and has received wide concern and interest. Especially while annual peak load had occured early evening in winter during past decades, but we found the trend has changed so that annual peak load occured during the daytime in summer since1981 The useful practicing methods of this load management ale as follows; 1. Inducing of midnight load by thermal storage water heating 2. Seasonal differential rates. 3. Revising the peak load priceing (Time-of -use) It seems hard to expect that load research can be carried out in a short time, and we all have to exert outselves continuously to provide efficient load management method without wasting resources.