• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1664-1667
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• 2005

The main function of Ball-Stop part is to operate power shift for vehicle with more than 5 ton when a driver changes gear using suitable force. This paper presents the implementation of a DFSS(Design For Six Sigma) for robust design of Ball-Stop part of power shift. The factors influencing Ball-Stop part performance is derived to find control factor. Based on this factor, contact force between head and detent pin analysis is performed to get optimal factor is analyzed and compared with contact force test result to verify reliability of design. This makes clear the reason why the proposed one is necessary and the role of DFSS.

• Journal of the Korean Society of Food Culture
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• v.10 no.1
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• pp.57-66
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• 1995

The purpose of this study was to evaluate the management practices and to measure the degree of job satisfaction of employees of hamburger chain restaurants in Seoul. Management practices were evaluated in terms of service, quality, cleanliness and shift management in 30 hamburger restaurants of 3 domestic and 3 foreign chain brands. Employee job satisfaction was measured by using questionnaires of Job Descriptive Index. 200 employees from the same 30 restaurants were participated in the survey. Results were analyzed by using SAS program in terms of t-test, one-way ANOVA, and Pearson's correlation. The results are as follows: 1. The factor of quality got the highest score and cleanliness the second, service the third, and shift management got the lowest score in the evaluation of management practiecs of hamburger chain restaurant. The foreign brands showed significantly higher scores than the domestic ones in every measured factors. 2. The factor of coworkers got the highest score and then supervision, the work-itself, promotion and pay got the next highest scores in descending order in measured Job satisfaction. The foreign brands showed significantly higher scores than domestic ones in JDI. 3. The foodservice employees rated work-itself was considered by employees the most important job satisfaction factor, and the next important factor was pay and then coworkers, supervision, and promotion. 4. The significant positive relationship between management practice factor of shift management and all the factors of job satisfaction except the factor of pay were found.

• Journal of Drive and Control
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• v.17 no.4
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• pp.141-151
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• 2020

The aim of this study was to analyze the safety factor of range-shift gear pairs on multi-purpose agricultural implement machinery for an optimal design of a transmission system. Gear-strengths such as bending and contact stress and safety factors were analyzed under three load conditions: an equivalent engine torque at plow tillage, a rated engine torque, and the maximum engine torque. Root and contact safety factor were calculated to be 3.88, 5.14, 2.24, 2.11, 2.21, 0.99 and 0.78, 0.94, 0.65, 0.68, 0.84, 0.85, respectively, under equivalent engine torque condition at the plow tillage. The root and contact safety factor were calculated to be 1.91, 2.53, 1.10, 1.04, 1.07, 0.48 and 0.55, 0.66, 0.46, 0.48, 0.59, 0.59, respectively, under rated engine torque condition. The root and contact safety factor were calculated to be 1.60, 2.11, 0.92, 0.87, 0.90, 0.40 and 0.51, 0.61, 0.42, 0.44, 0.54, 0.54, respectively, under the maximum engine torque condition. The multi-purpose agricultural implement machinery could be conducted under plow tillage operation. However, gear specifications for tooth surface need modification because the gear surface would be broken at all driving conditions as safety factors are lower than 1.

• Korean Journal of Occupational Health Nursing
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• v.13 no.2
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• pp.118-129
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• 2004

Purpose: The purpose of this study is to investigate effects of shift work on married nurses' role conflict and job satisfaction. Method: Study subjects consisted of married nurses employed at four general hospitals with over 500 beds located in Seoul and Kyunggi area. The data were collected from March 15th to April 7th, 2004 using the survey and the subjects were asked to reply through self-administrative method. Results: Mean value of role conflict of nurses who worked shift work was measured 3.12 out of 5, and that of nurses who did not was measured 2.98. Mean value of job satisfaction of nurses who worked shift work was measured 2.79 out of 5, and that of nurses who did not was measured 2.86. There was a significant reverse correlation between mean level of role conflict and of job satisfaction. Both groups, nurses who worked shift work and nurses who did not, showed significant reverse-correlation in two areas. In the case of nurses who worked shift work, role conflict not showed a significant correlation. Job satisfaction showed a significant correlation with the plan to work as a nurse and remuneration in the case of nurses who worked shift work. Duty of supporting family was the factor affecting role conflict and measured 4.2% in the case of nurses who worked shift work, and the plan to work as a nurse and the academic background in the case of nurses who did not work shift work. Conclusion: To reduce role conflict and to improve the degree of job satisfaction, there should be taken a measure to improve a financial compensating system for working shift work for nurses who worked shift work, and to help nurses not working shift work to design plans for their job as nurses with stability.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.17-30
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• 2012

This study analyzes the basic characteristics needed for motivating modal shift from truck to rail. The object of the study is to consider the resistance factor for container transported inland and the object point is the transfer node where modal shift occurs. The main contents of the study are as follows. First, the study looks at what shippers, engaged in inland transport of container, think of current transfer node environment. From this, the study analyzes what resistance factors are attributable to the lack of motivation in modal shift from truck to rail. Second, the study estimates mode choice models in which the resistance factors at transfer node are applied. Also by using this, the study draws out elasticities, and analyzes characteristics of resistantance factors in modal shift. Third, as its result, the study suggests methods to promote modal-shifting container transport from truck to rail.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.951-958
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• 2013

This paper proposes the controller design for a stability improvement of an on-board battery charger. The system is comprised of a power factor correction (PFC) circuit and phase shift full-bridge DC-DC converter. The PFC circuit performs the control of the DC-link voltage and the input power factor. The DC-DC converter regulates the voltage and the current in the battery using the DC-link voltage. This paper proposes the design method of PI controller for the PFC circuit using a small signal model. The analysis and design of a type-three controller for the DC-DC converter is also presented. A simulation and experiment has been performed on the on-board battery charger and their results are presented to verify the validity of the proposed system.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.3
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• pp.405-418
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• 2017

SHIFT is public rental housing policy introduced by Seoul Metropolitan in 2007, which works as Chonsei(korean unique deposit rental system). This paper examines the effect of SHIFT on Chonsei prices of neighborhood apartments. To estimate the change in prices of Chonsei after the provision of SHIFT, I collect data on Chonsei prices of apartments within a 5km radius from the SHIFT housings. Summary of main results are following. Chonsei prices of the apartments within a 2-3km radius decreased by 4.4% after the provision of SHIFT housings. In contrast, when it comes to apartments within a 1-2km radius, I can't find the stochastic relationship between the provision of SHIFT hosing and price changes. This results can be explained by "Offset effects" caused by real estate development. Provision of SHIFT can sequentially induce nearby area's development, which plays a factor in the effect of price increases. And this offset effects varies in each apartment complex depending on demand for Chonsei and supply of the SHIFT.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.1
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• pp.43-47
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• 2015

Background: The purpose of this study was to identify the effects of the blood flow on carotid and vertebral artery during the forward shift on head. Methods: A 20-year female healthy subject participated in this study. This study was set up the forward shift on head at the 3cm and 6cm in a shoulder midline (acromion). Measurement method were using duplex ultrasound with colour doppler imaging for the blood flow on carotid and vertebral artery. Results: Carotid artery was increased the blood flow and vertebral artery was decreased the blood flow during forward shift on head. Conclusions: These findings suggest that carotid and vertebral artery changes to the blood flow during forward shift on head. Therefore, we should be consider that hemodynamic factor when apply to the therapeutic exercise for patients of forward head posture.

• Journal of Korean Biological Nursing Science
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• v.19 no.4
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• pp.252-257
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• 2017

Purpose: This study aimed to investigate the associations of sleep, dietary behaviors and physical activity with quality of life among shift-work nurses. Methods: For this cross-sectional descriptive study, data were collected from 191 shift-work nurses in a tertiary hospital. Multiple linear regression analysis was used to identify the relationships among variables. Results: The levels of sleep quality, dietary behaviors and physical activity were low. Factors associated with quality of life among shift-work nurses included sleep disturbance (B=-0.16, ${\beta}=-0.26$, p<.001), dietary behaviors (B=0.28, ${\beta}=0.24$, p<.001), and physical activity (B=0.05, ${\beta}=0.19$, p<.001). The strongest factor was sleep disturbance. Conclusion: In order to improve quality of life among shift-work nurses, it is significant to encourage and maintain health behaviors such as sleep, dietary behaviors and physical activity. Under the circumstances where shift-work cannot be avoided, personal efforts made by nurses to establish their own living standards for positive health behaviors will benefit their quality of life.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.73-80
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• 2016

This study highlights the main effect of job demand, work shift, work environment and stressors on the railway traffic controller's health, and the moderating effect of work0life balance. The result of empirical analysis based on questionnaires received from 328 traffic controllers working at 10 railway operating companies indicates that job demand, work shift, work environment and stressors have significant effect on their health, among which stressors is a major factor. In the respect of moderating effect, WLB showed no significance except for job demand. This result implies that controller's health can not be enhanced through their individual family or leisure life. Therefore, effective countermeasures and policy to mitigate their health problems and heal their symptoms are urgent.