• Structural Engineering and Mechanics
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• v.76 no.5
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• pp.561-578
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• 2020

The present work addresses the surface integrity and chip morphology in finish hard turning of AISI D3 steel under nanofluid assisted minimum quantity lubrication (NFMQL) condition. The surface integrity aspects include microhardness, residual stress, white layer formation, machined surface morphology, and surface roughness. This experimental investigation aims to explore the feasibility of low-cost multilayer (TiCN/Al2O3/TiN) coated carbide tool in hard machining applications and to assess the propitious role of minimum quantity lubrication using graphene nanoparticles enriched eco-friendly radiator coolant based nano-cutting fluid for machinability improvement of hardened steel. Combined approach of central composite design (CCD) - analysis of variance (ANOVA), desirability function analysis, and response surface methodology (RSM) have been subsequently employed for experimental investigation, predictive modelling and optimization of surface roughness. With a motivational philosophy of "Go Green-Think Green-Act Green", the work also deals with economic analysis, and sustainability assessment under environmental-friendly NFMQL condition. Results showed that machining with nanofluid-MQL provided an effective cooling-lubrication strategy, safer and cleaner production, environmental friendliness and assisted to improve sustainability.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.2
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• pp.117-131
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• 2018

This study analyzed the personal characteristics of the SW industry workers and investigated how these individual characteristics affect the satisfaction of job satisfaction. In addition, we examined how satisfaction with these jobs varies according to satisfaction with internal control and external compensation. This study surveyed the employees of SW industry in Seoul and Daegu from September 15 to October 15, 2017. The results of this study are as follows. First, personal characteristics have a significant effect on job satisfaction. Second, extroversion, openness, friendliness and integrity have a significant effect on job satisfaction. This is consistent with the previous study (Park and Song, 2005), which suggests that people with extroversion are more likely to feel positive emotions such as joy. In addition, it is believed that open empathy has a tendency to share with others in work, and positive emotions in work have a significant influence because they show high achievement in work. A friendly person places great importance on a comfortable and harmonious relationship with others, so he builds and maintains good relationships with the members of the organization by trusting others in the organization. Third, nervousness showed no significant effect on job satisfaction. This is consistent with the previous study (Yoo, 1987) in which the more nervousness is, the more unpleasant emotions work and the more negative emotions and negative experiences occur. Fourth, personal characteristics have positive effects on job satisfaction in the moderating effects of intrinsic compensation and external compensation. There is a difference in job satisfaction due to intrinsic compensation and external compensation.

• Journal of Korean Association for Spatial Structures
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• v.23 no.2
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• pp.19-28
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• 2023

Timber structures are susceptible to moisture, contamination, and pest infestation, which can compromise their integrity and pose a significant fire hazard. Despite these drawbacks, timber's lightweight properties, eco-friendliness, and alignment with current architectural trends emphasizing sustainability make it an attractive option for construction. Moreover, timber structures offer economic benefits and provide a natural aesthetic that regulates building temperature and humidity. In recent years, timber domes have gained popularity due to their high recyclability, lightness, and improved fire resistance. Researchers are exploring hybrid timber and steel domes to enhance stability and rigidity. However, shallow dome structures still face challenges related to structural instability. This study investigates stability problems associated with timber domes, the behavior of timber and steel hybrid domes, and the impact of timber member positioning on dome stability and critical load levels. The paper analyzes unstable buckling in single-layer lattice domes using an incremental analysis method. The critical buckling load of the domes is examined based on the arrangement of timber members in the inclined and horizontal directions. The analysis shows that nodal snapping is observed in the case of a concentrated load, whereas snap-back is also observed in the case of a uniform load. Furthermore, the use of inclined timber and horizontal steel members in the lattice dome design provides adequate stability.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.211-218
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• 2010

The purpose of this study was to examine preference for dental hygienists. The subjects in this study were 228 employees in general hospitals located in the region of Busan, on whom a survey was conducted in May and June, 2009. The findings of the study were as follows: As for top priority of dental hygienists' duties, providing assistance for dentist treatment ranked first(28.2%), followed by scaling(23.2%) and preventive duties(20.6%). Concerning a favorable image of a dental hygienist, a cheerful look was most preferred(61.4%), followed by a clean-cut look (32.9%), a refined look (3.5%) and an intellectual look (2.2%). Among the subjects, married respondents exhibited a greater liking for a cheerful look, and the gap between them and the unmarried subjects was statistically significant($x^2=8.11$, p<.05). In terms of uniform preference, a two-piece suit with pants was most favored(76.3%). Female respondents showed a greater preference for a two-piece suit with pants, and the gap between them and the male respondents was statistically significant($x^2=41.09$, p<.001). As for major qualifications, professional knowledge was most valued (49.1%), followed by integrity/responsibility(23.2%), friendliness(22.4%), and a great personality/being well-cultivated(5.3%). Employees who were in their 40s and up placed more importance on integrity and responsibility, and the gap between them and the others was statistically significant($x^2=20.62$, p<.01).