• Journal of Energy Engineering
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• v.22 no.3
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• pp.287-293
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• 2013

This study was carried out to diminish the formation of scale in boilers which is one of the defect elements when they are operating. The defect relating to scale can cause a fatal impact on the explosion of boilers due to the overheating of their tubes, or it can affect the flow of water inside boilers with its bad circulation and result in a disparity of water inside the equipment. Heat transfer in the scale is low comparing to the boiler material, so it can lead to energy losses and has also impact on the global warming. In 2005, the Korean government introduced a system which requires boiler users to install the equipment which can prevent or eliminate the formation of scale to improve the management of water quality in boilers. The study on the techniques for preventing or eliminating the formation of scale started in 1821 and since then subsequently there have been lots of similar studies. The first one was about the scale reduction using potato starch. Since an ultrasonic scale preventer developed by a scientist from a Russian acoustic institute was introduced in1993, a variety of equipment of this kind have been disseminated in Korea. There has been a need to demonstrate the condition for the best performances of such equipment. Boilers are mostly composed of the main body and 288 the tube with a circular curved surface. I carried out a demonstration study on a circular tube which affects the scale defect the most among the boiler components. As a result of it, I found out the fact that the ultrasonic wave needs to reach a certain level of sound pressure and frequency to affect the formation of scale.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.178-192
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• 2013

This study is for the analysis of the influence that the factors(communication, domestic life, offensive action, economic problem) of marital conflicts of old age and ecological systems factors(individual, family, sociality) have a impact to the divorce of elderly(thoughts and attempts of divorce) and the impulse to commit a crime(violence, egoism, running away from home). The guinea pigs is 350 married people of ages greater than 55 in the capital area. The 338 collected data excluding incomplete 12 data were analyzed. Statistical methods used in this study were factor analysis, frequency analysis, reliability analysis, t-test, ANOVA, Hiearchical regression analysis and Scheffe test with SPSS 18.0. The result are as follows. First, the marital conflict and ecological systems have a severe impact to the divorce of elderly, the more the conflict of the domestic life and the offensive action, the conflict in communicative and economic problem are getting higher. Second, the marital conflict and ecological systems have a severe impact to the impulse to commit a crime, the more the conflict of a domestic life and the conflict caused by spouse's attack, the economic problem, the egotistic impulse are getting higher. Third, there are some statistically similar differences of all the parts(sex, academic ability, job, children coresidence, religion, physical condition, monthly average income) in the marital conflict by characteristic of sociology of population, ecological systems, the divorce of elderly and the impulse to commit a crime.

• Archives of design research
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• v.17 no.3
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• pp.111-122
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• 2004

The purpose of this study are two the first is to identify the positioning of product design and analyze its functional relationship with product development, manufacturing, marketing and sales in the comprehensive competitiveness evaluation model ; and the second is to estimate the determinants of QCI(quality competitiveness index), analyze the impact of product design on QCI, and compare the aforementioned results for the seven industrial sectors and the five product patterns. For this empirical analysis, this study surveyed 400 Korean manufacturing firms during August-October 2003. The major empirical findings are summarized as follows : First, the hypothesis on the positive effect of product design on QCI is accepted at a highly significant level (p < 0.001) for all : the manufacturing sector, seven industrial sectors, and five product categories. Second, the correlation analysis and factor analysis lead to the result that the effect of product design on QCI is estimated to be relatively very low, in comparison to those of product functionality and basic performance on QCI. These findings imply that Korean manufacturing sector has been still in the prematured stage at which product design has not played an important role yet. This study concludes that product design in line with other functions (product development, manufacturing, marketing, and sales) should make a good contribution to the improvement of QCI in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.530-537
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• 2020

The purpose of this study was to determine the factors affecting the satisfaction with pre-service childcare, the work related stress, and the conflicts perceived by pre-service childcare teachers. The data was processed using the SPSS Statistical Package Program, and the frequencies, means, and standard deviations were calculated. Reliability analysis, correlation analysis, and multiple regression analysis were also conducted. The results showed that the class contents, the environment of childcare practice, and the conflicts with children were stressful and they negatively affected practice satisfaction. Second, there was statistically significant negative correlation between the pre-service teachers' childcare practice stress, conflict during the practice, and practice satisfaction. Third, the stress of preservice teachers' childcare practice and the conflict felt during the practice also affect the childcare practice satisfaction. Based on these findings, further study is needed for implementing effective measures in order to improve the practice satisfaction with exhaustive pre-practical education and the field job-oriented curriculum. These measures will enable students majoring in childcare to experience less stress and conflicts during their education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2483-2490
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• 2010

The purpose of this study is to offer information on the more effective sports wear to club members, who are participating in badminton, by closely examining influence in lifestyle of participants in badminton upon the sportswear benefit sought. The subjects of this study were selected male and female adults, who are joining now by subscribing to badminton club in Gangwondo Province, as the population. It sampled totally 206 people by convenience sampling, and carried out frequency analysis, reliability & factor analysis, and multiple regression analysis by using SPSS/PC+ 11.0 Version. The conclusions of this study are as follows. First, it was indicated that there is correlation between lifestyle and sportswear benefit sought of participants in badminton. Second, it was indicated to have influence upon the ideal benefit sought, which is the sportswear benefit sought, in order of the fashion sought bandwagon and the social orientation, which are sub-factors of lifestyle. Third, it was indicated to have influence upon the fashion & brand benefit sought, which is the sportswear benefit sought, in order of the material sought, the fashion sought bandwagon, and the satisfaction with reality, which are sub-factors of lifestyle. Fourth, it was indicated to have influence upon the convenience benefit sought, which is the sportswear benefit sought, in order of the self-loyalty, the social orientation, the health sought, and the satisfaction with reality, which are sub-factors of lifestyle. Fifth, lifestyle was indicated to have influence upon the youth & individuality benefit sought in order of the fashion sought bandwagon, the material sought, and the social orientation. The sportswear product in the better quality will be able to be expected for sports activity, by which the subjects of participating in sports activity correctly grasp the sportswear benefit sought, based on these results.

• Tunnel and Underground Space
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• v.30 no.2
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• pp.164-179
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• 2020

Applying the limit state design method to geotechnical structures, accuracy and reliability of its design are mainly affected by parameters for geotechnical site characteristics, such as unit weight, Poisson's ratio, deformation modulus, cohesion and frictional angle. When the structures are located in weathered ground, especially, cohesion and frictional angle of ground are closely related with decision of parameters for structures' load and ground's resistance. Therefore, the accurate determination of these parameters, which are commonly obtained from field measurement, such as borehole shear test, are essential for optimum design of geotechnical structures. The 38 case studies, in this study, have been analyzed for understanding the importance of these parameters in designing the ground structures. From these results, importance of field measurement was also ascertained. With these evaluations, an apparatus for determining the strength characteristics, which are fundamental in limit state design (LSD) method, have been newly developed. This apparatus has an improved function as following the ASTM suggestion. Through the field application of this apparatus, the strong point of minimizing the possibility of error occurrence during the measurement has been verified and authors summarized that the essential parameters for LSD can be qualitatively obtained by this apparatus for determination of strength characteristics of weathered ground.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.3984-3993
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• 2011

The purpose of this study was to examine the impact of participation in sport for all on leisure satisfaction, psychological wellbeing and subjective wellbeing in an attempt to make a contribution to the leisure satisfaction, psychological wellbeing and subjective wellbeing of people enjoying sport for all. The subjects in this study were 200 people who were selected by convenience sampling from a population of male and female adults who participated in sport for all in Gangwon Province. The statistical package SPSS 11.0 was employed to make a frequency analysis, reliability analysis, factor analysis and multiple regression analysis. The findings of the study were as follows: First, participation in sport for all had a statistically significant impact on leisure satisfaction. Those who more participated in sport for all expressed more satisfaction with their leisure life. Second, leisure satisfactionexerted a statistically significant influence on psychological wellbeing. Third, leisure satisfaction affected subjective wellbeing in a statistically significant way. The findings of the study indicated that the leisure satisfaction of those who participated in sport for all exercised a great physical and mental influence on themselves. Those who don't participate in sport for all should steadily be advised to do that, and the national and local governments should develop a wide variety of sport-for-all programs to let everybody lead a better life by enjoying sport for all.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.239-246
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• 2021

Portal Dosimetry was verified using EPID to secure the clinical application and reliability of the existing research dose evaluation. The dose distribution of Geant4 was compared with the measured value by 360° rotational irradiation with a 2.5 cm cone for stereotactic brain surgery. To confirm the dose distribution of patients with brain metastasis, the dose distribution investigated by inserting a Gafchromic EBT film into the parietal phantom and the dose distribution obtained from the parietal phantom using VMAT are compared and applied to actual patients. As a result of the analysis, it was confirmed that the accuracy of the beam center and the center of the couch coincide accurately with an error within 1mm as a result of QA through a pin ball. In addition, it was confirmed that the EBT3 film has excellent linearity in the range of 0 to 10 Gy according to various dose irradiation. In the same setting as the two cervical phantoms, we confirm that the implementation and simulation results calculations of dose calculations based on Geant4 using photon beams match the experimental data within the treatment planning volume (PTV). Therefore, volume modulated arc treatment (VMAT) 360° rotational irradiation was performed, and the result of iso-dose distribution analysis by rotational irradiation confirmed that it is appropriate to include a virtual tumor.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.403-411
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• 2018

Purpose : The purpose of this study is to analyze how the certain efforts of the optical shops affect on opticians' job satisfaction and organizational commitment, and to analyze how opticians' job satisfaction and organizational commitment affect on the customer orientation and to suggest the method of maintaining competitiveness. Methods : Two hundred opticians took participations on the surveys via the Internet survey method and social network system (SNS), and SPSS 18.0 statistics program was used for data analysis; frequency analysis, T-test, factor analysis, reliability analysis, and multiple linear regression analysis were conducted. Results : It is analyzed the differences on the job satisfaction and organizational commitment in accordance with type of optical shops, conducting 5 working days/week and flexible time. As a result, higher job satisfaction is presented with 5 working days/week. Relationships with co-workers statistically affect on job satisfaction positively and emotional labor and work overload statistically affect on job satisfaction negatively. In addition, relationships with co-workers and reward statistically affect on organizational commitment positively and emotional labor and work overload statistically affect on organizational commitment negatively. And opticians' job satisfaction and organizational commitment statistically affect on customer satisfaction positively. Conclusion : It is necessary for the optical shops to make an effort for their opticians to improve the job satisfaction and organizational commitment. And to do so, it is needed to form trusting and respecting relationships with co-workers or superiors. In addition, it is necessary to have continuous communication and education for opticians' self-management. Also, it is needed to establish an effective reward system.

• Journal of vocational education research
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• v.37 no.3
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• pp.47-63
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• 2018

The purpose of this study is to develop the competency model of specialized vocational school teachers as admission officers. Whereas professional admission officers deal with a variety of admission activities in universities, teachers are responsible for admission duties in specialized high schools in Korea. Therefore, it is necessary to identify the core competencies required for teachers responsible for admission duties in specialized high school settings. In order to develop a competency model, factor analysis was completed for the survey results of 191 teachers who teach in specialized vocational high schools in Seoul, Korea. For evaluating validity of the competency model, the responses from those who had high experiences in admission duties and the average teachers were compared. As a result, this study identified a total of 14 competencies in three competency areas. The competencies required for specialized high school teachers include responsibilities for admission officers, ethics for evaluators, communication skills, teamwork, understandings of admissions process for specialized vocational high school, developing evaluation criteria, generating interview questions, increasing interrater reliability, interview skills, simultaneous evaluation of interviewees, quantification of evaluation results, synthesis of evaluation results, and decision making skills.