• International Journal of Precision Engineering and Manufacturing
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• v.4 no.3
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• pp.36-41
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• 2003

This paper describes a numerical analysis of a non-steady state porthole die extrusion, which is useful for manufacturing long tubes with a hollow section. Materials divided through several portholes are gathered within a chamber and are then welded under high pressure. This weldability classifies the quality of tube products and is affected by process variables and die shapes. However, porthole die extrusion has been executed based on the experience of experts, due to the complicated die assembly and the complexity of metal flow. In order to better assist the design of die and to obtain improvement of productivity, non-steady state 3D FE simulation of porthole die extrusion is required. Therefore, the objective of this study is to analyze the behavior of metal flow and to determine the welding pressure of hot extrusion products under various billet temperatures, bearing length, and tube thickness by FE analysis. The results of FE analysis are compared with those of experiments.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.537-547
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• 2017

This study attempted to determine differences between the perceived empowerment level and job satisfaction depending on hairdressers' demographic characteristics and analyze the effects of their empowerment on job satisfaction. For this, a total of 310 hairdressers in Gwangju-Jeonnam and Seoul-Gyeonggi-do were chosen through convenience sampling, and then a questionnaire survey was conducted. The valid 277 copies were used for final analysis. For data analysis, descriptive statistics, factor analysis, reliability analysis, t-test, ANOVA, Duncan's test, and multiple regression analysis were conducted using SPSS 15.0. The study results found the following: First, in terms of the subordinate factors of empowerment, the following four factors were found: meaningfulness, self-determination, competence, and impact. Second, depending on demographic characteristics (e.g., age, career, type of beauty salon, job title, punch-in time, monthly pay), a statistically significant difference was found between empowerment and job satisfaction (p<.01). Third, hairdressers' perceived empowerment level had a positive impact on job satisfaction (p<.01). In terms of the empowerment on job satisfaction by sub-factor, 'self-determination' was largest, followed by 'meaningfulness' and 'competence.' Therefore, beauty salon owners need to manage their business more efficiently by converging cosmetology and business management by expanding empowerment among hairdressers properly after recognizing the importance of hairdresser empowerment.