• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.172-179
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• 2020

The impact of effective parameters on the electrodeposition rate optimization of Au-Cu alloy at high thicknesses on the silver substrate was investigated in the present study. After ensuring the formation of gold alloy deposits with the desired and standard percentage of gold with the cartage of 18K and other standard karats that should be observed in the manufacturing of the gold and jewelry artifacts, comparing the rate of gold-copper deposition by direct and pulsed current was done. The rate of deposition with pulse current was significantly higher than direct current. In this process, the duty cycle parameter was effectively optimized by the "one factor at a time" method to achieve maximum deposition rate. Particular parameters in this work were direct and pulse current densities, bath temperature, concentration of gold and cyanide ions in electrolyte, pH, agitation and wetting agent additive. Scanning electron microscopy (SEM) and surface chemical analysis system (EDS) were used to study the effect of deposition on the cross-sections of the formed layers. The results revealed that the Au-Cu alloy layer formed with concentrations of 6gr·L^-1 Au, 55gr·L^-1 Cu, 24 gr·L^-1 KCN and 1 ml·L^-1 Lauryl dimethyl amine oxide (LDAO) in the 0.6 mA·cm^-2 average current density and 30% duty cycle, had 0.841 ㎛·min^-1 Which was the highest deposition rate. The use of electrodeposition of pure and alloy gold thick layers as a production method can reduce the use of gold metal in the production of hallow gold artifacts, create sophisticated and unique models, and diversify production by maintaining standard karats, hardness, thickness and mechanical strength. This will not only make the process economical, it will also provide significant added value to the gold artifacts. By pulsating of currents and increasing the duty cycle means reducing the pulse off-time, and if the pulse off-time becomes too short, the electric double layer would not have sufficient growth time, and its thickness decreases. These results show the effect of pulsed current on increasing the electrodeposition rate of Au-Cu alloy confirming the previous studies on the effect of pulsed current on increasing the deposition rate of Au-Cu alloy.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.2
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• pp.103-110
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• 2010

In this paper, a new mode changeable asymmetric full bridge dc/dc converter is proposed to solve the freewheeling current problem of the conventional zero voltage switching(ZVS) phase shift full bridge(PSFB) dc/dc converter of low output voltage and high output current applications. The proposed converter is operated as an asymmetric full bridge converter when the duty cycle is less than 50% and active clamp full bridge converter when the duty cycle is greater than 50%. As a result, since its freewheeling current is eliminated, the conduction loss is lower than that of the conventional ZVS PSFB dc/dc converter. Moreover, ZVS of all power switches can be ensured along a wide load ranges and output current ripple is very small. Therefore, high efficiency of the proposed converter can be achieved. Especially since its operation mode is changed to the active clamp full bridge converter during hold up time and can be operated with 50~100% duty ratio, it can produce the stable output voltage along wide input voltage range. The operational principles, theoretical analysis and design considerations are presented. To confirm the operation, validity and features of the proposed converter, experimental results from a 1.2kW($400V_{dc}/12V_{dc}$) prototype are presented.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.24-31
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• 2020

The duty of construction clients in WSH (Workplace Safety and Health) system was included in the amendment of Occupational Safety and Health Act (enforced on 16 January 2020), which was estimated the shift of paradigm in the prevention of construction accidents. The purpose of this paper is to introduce the analysis results of construction clients' role in the construction project, which were performed by authors over the recent years in order to impose the duty on construction clients, and to suggest their role according the plan, design, and construction stage. Utilizing the systematic literature review process based on Meta analysis, the related papers were selected. For the selected papers, related domestic and foreign regulations, and other prominent report, the construction clients' role was analyzed by reflecting the experts' advice. Results show that the construction clients should control the designer and contractor for implementing the WHS system during the whole process of the construction project. They should supply sufficient source and time to ensure the workers' safety. In the plan stage, the key role of construction clients is to identify intensively controlled hazard and risk reduction plan and to transfer the results. In the design stage, their key role is to select the designer with the capacity in WSH and to assist the designer for the safety design. The main key role of construction clients in the costruction stage is to select the contractor with specialty in WSH including a contract reflecting the WSH requirement and to check implementation of WSH plan, WSH cost, WSH education, and accident report. In addition, it is thought that the construction clients' participations in the site WSH activity and adjustment of safety and health problem among contractors can be effect in the prevention of construction accidents.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.186-194
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• 2008

The purpose of this study is to analyze the level of job satisfaction and organizational commitment of administrative staffs in hospitals. The data for this study were collected through a self-administered survey with a structured questionnaire for 338 persons from administrative staffs working in hospitals in Ulsan and Busan Metropolitan cities. The job satisfaction(factors such as wage, performance, duty, promotion and personal relations) and organizational commitment were scored from 5(very satisfied) to 1(very unsatisfied). The collected data from the survey were analyzed by frequency, ANOVA, correlation analysis and multiple regression analysis. The results are as follows: Medical technicians, health administrators, nurses and the others were ranked in order in the job satisfaction. Medical technicians, nurses, health administrators, and the others were ranked in order in the organizational commitment. The correlation analysis showed that the job satisfaction and the organizational commitment had positive correlation in the factors of wage, performance duty, promotion and personal relations.

• Korean Journal of Optics and Photonics
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• v.12 no.1
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• pp.17-24
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• 2001

Two-dimensional binary-phase diffraction gratings which can be employed to fabricate two- and three-dimensional periodic structures are designed and analyzed using rigorous coupled-wave analysis. These gratings serve as phase-masks which generate several diffracted waves from a normally incident beam and thus can produce a periodic interference pattern in space via nearfield holography. The properties of the diffracted beams can be controlled by varying the polarization and wavelength of the incident beam, surface-profile, groove depth and duty cycle of the mask. For the two-dimensional structure, optimum results can be obtained when the diffraction efficiency of the zero-order beam is minimized while that of the first-order maximized. On the other hand, when the diffraction efficiency of the zero-order is appreciable or even greater than other orders, we can obtain a variety of three-dimensional interference patterns which may be used to fabricate photonic crystals of tetragonal-body-centered and hexagonal structures in a submicron scale. scale.

• Journal of Korean Academy of Nursing
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• v.38 no.6
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• pp.853-865
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• 2008

Purpose: The aim of this study was to develop and to analyze the task of gerontological nurse practitioners (GNPs) in Korea. Methods: The definition of GNP and job description was developed based on developing a curriculum (DACUM) by 7 panels who have experienced in DACUM analysis and gerontological nursing. One hundred sixty nurses who were working at long term care facilities were participated. The questionnaire included frequency, importance, and difficulty of duties, tasks, and task elements. The data were collected in November 2006, analyzed by descriptive statistics. Results: The job description of GNPs in Korea revealed 5 duties, 23 tasks, and 86 task elements. On the all five duties, the highest duty in frequency and in importance was professional nursing care ($3.25{\pm}0.35$, $3.49{\pm}0.29$). But the highest duty in difficulty was research ($3.24{\pm}0.46$). 'Prevent health problem ($3.42{\pm}0.43$, $3.56{\pm}0.33$)', 'Teach other staffs ($2.83{\pm}0.77$, $3.39{\pm}0.43$)', 'Develop the evidence-based standards ($2.43{\pm}0.76$, $3.22{\pm}0.43$)', 'Develop the self ($2.81{\pm}0.65$, $3.26{\pm}0.42$)', and 'Participate the team activities' were the highest score in frequency and in criticality of tasks. 'Provide emotional support to older adults and families ($3.16{\pm}0.41$)', 'Counsel older adults and their families ($3.14{\pm}0.49$)', 'Do clinical research ($3.32{\pm}0.49$)', 'Quality insurance ($3.25{\pm}0.49$)', and 'Build collaborative system ($3.18{\pm}0.47$)' were perceived the most difficult tasks. Conclusion: The political efforts for the legislation of role and task of GNPs were needed.

• Journal of the Korean Society of Costume
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• v.65 no.2
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• pp.62-74
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• 2015

The purpose of this research is to analyse the process of development and verification of 'National Competency Standards' of Hanbok production, which was carried out in 2013 for the fashion industry. As the result of this research, the definition of the duty in Hanbok production is 'to conduct a series of step-by-step processes of planning and developing fabric and design, then making pattern, cutting fabric and sewing.' The competency unit for Hanbok production is analyzed in 10 categories: analysis of market trends, design plan, production and manipulation of fabric, production process plan, sample making, pattern making, cutting out, sewing, finishing sewing, inspection of the product quality. Competency unit elements of each competency unit are as follows. 1) analysis of market trends: to research market trend resources, to analyse consumers' buying trend, to analyse industry changes, 2) design plan: to develop design, to plan fabrication, to draw flats, 3) production and manipulation of fabric: to develop fabric planning, to prepare fabric manipulation, to conduct fabric manipulation, 4) production process plan: to grasp design, to plan sewing method, to prepare a specification sheet, 5) sample making: to make a sample pattern, to cut sample fabrics, to sew sample, to finish sample making, 6) pattern making: to measure body, to make production pattern, to adjust production pattern, 7) cutting out: to care fabrics, to lay out patterns, to cut out fabrics, 8) sewing: to sew a garment, to sew a lining, to attach a lining, 9) finishing sewing: to neaten edges, to attach trims, to press to finish, 10) inspection of the product quality: to confirm correspondence with the specification sheet, to inspect appearance.

• Korean Security Journal
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• no.28
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• pp.79-102
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• 2011

This is a follow-up research of Oh Jae Hwan(2010) aimed to confirm the influence of the educational program of improved question search methods on the duty and job satisfaction of private security guards. For this research, a survey was conducted on a sampling of 170 private security guards living in Seoul and Gyeonggi province, as selected in the research of Oh Jae Hwan(2010). A frequency analysis, correlation analysis and multiple regression analysis were conducted on the collected data by using the SPSS 15.0. The Cronbach's ${\alpha}$ value of the reliability of the survey was over 0.800. The analyzed result of the research is as follows. It was found that when there was an increase in the content of educational training of the program there was also an increase in the job satisfaction and performance. This signifies that the contents of the improved educational program includes scientific and systematic techniques such as METT and action promoting questions, the adequately constructed practical skill education allows private guards to have confidence in their duty, the research reflects the current trends and has a high possibility of utilization due to its high relevance to the duties of private security guards.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3127-3137
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• 2018

The study has been focused on identifying the impact of professors' types of leadership on major satisfaction, learning immersion in college students. To achieve this goal, the results of a survey of 543 affiliated students from september 2017 to november were as follows. Data processing has been done using the IBM SPSS statistics 25 program, and t-test and multi-return analysis were performed to determine the characteristics of the survey subjects, to verify the validity and reliability of the survey tools, and to identify differences and influence between factors. First, there was a difference between gender and grade, but by major, there was no difference. Second, learning immersion varies by major, gender and grade. Third, the factors that significantly influence a type of leadership's satisfaction with a major were shown to have a significant impact on vision and sense of duty, individual consideration, situational reward but were not significant in exceptional control by exception. Fourth, the impact of the types of leadership on learning immersion showed that vision and sense of duty, and situational reward, but individual consideration and exceptional control by exception were not significant.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.101-110
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• 1997

The circuit effects due to the transformer primary side series equivalent inductance in the Zero Voltage Switching Pulse Width Modulated Half Bridge DC/DC Converter and its impact on the effective duty are analyzed. The steady state equations and the small signal model of the converter are derived incorporating the effects of the complementary control and the utilization of transformer primary side series equivalent inductance. The open plant dynamics are analyzed on the basis of the model derived. The model predictions are confirmed by experimental measurements.