• Korean Journal of Occupational Health Nursing
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• v.33 no.3
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• pp.109-116
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• 2024

Purpose: This study aimed to identify the influence of work-life balance and insomnia severity on shift working nurses' health promotion behaviors. Methods: Participants were 152 nurses who worked rotating shifts at a general hospital. Data were collected from August 2 to 16, 2023 and analyzed by t-test, ANOVA, Pearson correlation, and multiple regression analysis using SPSS/WIN 25.0. Results: The participants exhibited high insomnia severity and low scores in both work-life balance and health promotion behaviors. Health promotion behaviors were positively correlated with work-life balance but negatively correlated with insomnia severity. The key factors influencing shift-working nurses' health promotion behaviors included work-life balance (β=.37, p<.001) and gender (female) (β=-.17, p=.026), with an explanatoty power of 18% (F=12.35, p<.001). Conclusion: Work-life balance is a significant variable affecting shift-working nurses' health promotion behaviors. The health of nurses is crucial not only for their personal well-being but also for ensuring the patient safety. Therefore, flexible work systems and adaptable health program schedules must be implemented to promote the health of shift-working nurses.

• Journal of the Korean Society of Costume
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• v.58 no.1
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• pp.90-103
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• 2008

This study aims to examine the current state of wearing working clothes for the workers who work in Electric Technology Division, Korea Railroad Corporation, to identify inconveniences and problems in relation to the working clothes, and based on the examination, to find a way to improve them, creating a design of summer working clothes that will have more advanced functionalities including activity adaptability and comfort. Survey was conducted through direct observation and interview for Electric Railway Power Team. A total of 352 copies were collected and analyzed. Based on the results of questionnaire, an experimental clothes, the functionality of which has improved in terms of design, material, and patterns, was created. The followings are the results of the study. Easy activity, design, and comfort are required as functions of working clothes. In design related questions, the survey shows high dissatisfaction in the color of existing working clothes, and preferred colors are dark blue and gray. With regard to the method of zipping up the front side, zippers are preferred. Although many pockets on the existing working clothes have high satisfaction, dissatisfaction to pocket format is high. In material related questions, lower dissatisfaction is indicated for the sense of touch, ventilation and sweat absorption. It is shown that the areas frequently polluted include the lower part of pocket, the edges of sleeves and elbow areas on the jacket. The frequently polluted area of the trousers include knee areas, the edges of pants and buttocks. With regard to the areas where the workers felt discomfort when motion, discomfort is highly indicated with armpits and back on the jacket. Also discomfort is highly indicated with crotch, buttocks and knee areas on the trousers. In material related questions, lower dissatisfaction is indicated for the sense of touch, ventilation, sweat absorption.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1343-1349
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• 2011

In this study, the power enhancement potential of a Rankine power cycle by transcritical operation was investigated by comparing the power of an HFC-134a subcritical cycle with that of an HFC-125 transcritical cycle, for a low-grade heat source with a temperature of about $100^{\circ}C$. For a fair comparison using different working fluids, each cycle was optimized by three design parameters from the viewpoint of power. In contrast to conventional approaches, the working fluid's heat transfer and pressure drop characteristics were considered in the present approach, with the aim of ensuring a more realistic comparison. The results showed that the HFC-125 transcritical cycle yields 9.4% more power than does the HFC-134a subcritical cycle under the simulation conditions considered in the present study.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.1
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• pp.172-181
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• 1993

Pseudo-Brayton cycle is defined as an ideal Brayton cycle admitting the difference between heat capacities of working fluid during heating and cooling processes. The endo-pseudo-Brayton cycle which is a pseudo-Brayton cycle with heat transfer processes is analyzed with the consideration of maximum power conditions and the results were compared with those of the endo-Carnot cycle and endo-Brayton cycle. As results, the maximum power is an extremum with respect to the cycle temperature and the flow heat capacities of heating and cooling processes. At the maximum power condition, the heat capacity of the cold side is smaller than that of heat sink flow. And the heat capacity of endo-Brayton cycle is always between those of heat source and sink flows and those of the working fluids of pseudo-Brayton cycle. There is another optimization problem to decide the distribution of heat transfer capacity to the hot and cold side heat exchangers. The ratios of the capacies of the endo-Brayton and the endo-pseudo-Braton cycles at the maximum power condition are just unity. With the same heat source and sink flows and with the same total heat transfer caqpacities, the maximum power output of the Carnot cycle is the least as expected, but the differences among them were small if the heat transfer capacity is not so large. The thermal efficiencies of the endo-Brayton and endo-Carnot cycle were proved to be 1-.root.(T$_{7}$/T$_{1}$) but it is not applicable to the pseudo-Brayton case, instead it depends on comparative sizes of heat capacities of the heat source and sink flow.w.

• Korean Journal of Agricultural Science
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• v.45 no.2
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• pp.290-297
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• 2018

Electric drive technology is continually advanced to improve fuel efficiency in the automobile industry. It could improve the fuel efficiency of automobiles by 50% as well as agricultural machinery. The purpose of this study was to measure and analyze the power and current of an electric transplanter based on the planting distances during field operations. The electric transplanter was constructed by mounting the major components of a motor drive system onto a transplanter. The electric transplanter had a 3 kW motor power, and the major components included an inverter, battery, and a battery management system (BMS). The field tests were conducted by travelling at two speeds (300 and 760 mm/s) and by planting at three distances (260, 420 and 630 mm) with the working speed (300 mm/s), during travelling and transplanting. The results showed that the required power increased when the travelling speed was fast. One-way ANOVA for the planting distance and Duncan's multiple range test at a significance level of 0.05 were used to analyze the motor power using statistical analysis software. In addition, the required power increased when the planting distances were short at every working condition. The results of this study would provide useful information for the development an electric transplanter.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.3 no.2
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• pp.17-23
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• 2007

Geothermal energy is used in various forms, such as power generation, direct use, and geothermal heat pumps. High temperature geothermal energy sources have been used for power generation for more than a century. Recent technical advances in power generation equipments make relatively low temperature geothermal energy to be available for power generation. In these applications, lower temperature geothermal energy source makes smaller difference between condensing water temperature and it. Various condensing water temperatures were investigated in analyzing its influence on power generation performance. Condensing water temperature of organic Rankine cycle imposed greater influence on power generation and its performance in lower temperature geothermal power generation.

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.83-88
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• 2004

As the electric system is getting larger to meet the increasing demand for electric power, the rating of power apparatus is becoming inevitably higher in its working voltage and larger in its capacity. According to KEPCO reports, power transformers in the KEPCO system have undergone troubles such as winding short insulation breakdowns every year since 1981. the cause of this troubles were high one line grounding fault currents in KEPCO systems that had direct grounding systems. KEPCO has installed the NGR(neutral grounding reactor) to lower this fault current and reduced winding short insulation breakdowns in power transformers. But when a circuit breaker opened a no load bus, some trips of circuit breakers for protecting transformer have occurred by mal-operation of 59GT(overvoltage ground relay) that detect disconnection of NGR. Therefore, in this paper, we analyzed the cause and examined the effect of time delav circuit to prevent wrong operation of 59GT.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.61-63
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• 1995

The main factors to bring out the power failure are trouble and operation power failure, the operation power failure of these includes about 85%. So, it is required that the without interruption of service method reduce the operation power failure. If we develop the without interruption of service method, the operation power failure will reduce greatly. It is necessary to develop the without interruption of service method which it solve various trobles (dissatisfacting solution of customer, sales revenue augmentation, and the reduction of the power failure negotiation work). The results of study are drawing up of the specification for temporary transmission methods, it of the working methods for them, and the scrutiny of the technology contents for them.

• Journal of Power Electronics
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• v.19 no.2
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• pp.591-601
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• 2019

With the development of renewable energy, grid-connected inverter technology has become an important research area. When compared with traditional silicon IGBT power devices, the silicon carbide (SiC) MOSFET shows obvious advantages in terms of its high-power density, low power loss and high-efficiency power supply system. It is suggested that this technology is highly suitable for three-phase AC motors, renewable energy vehicles, aerospace and military power supplies, etc. This paper focuses on the SiC MOSFET behaviors that concern the parasitic component influence throughout the whole working process, which is based on a three-phase grid-connected inverter. A high-speed model of power switch devices is built and theoretically analyzed. Then the power loss is determined through experimental validation.

• Analyses & Alternatives
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• v.2 no.2
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• pp.1-30
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• 2018

The concept of soft power presents both theoretical and practical difficulties for researchers and policy makers. This essay examines the practical use of soft power and argues that soft power resources in education are important for attracting individuals to migrate between countries and assimilate to the new language and culture of the new location. Japan's attempts to utilize soft power resources in its educational system have provided mixed results dependent on the target population. Japan has successfully attracted individuals into fields related to higher education much more so than skilled labor programs. This essay discusses the importance of educational soft power resources in Japanese strategy to increase educated working population that is assimilated to Japanese language and culture. After reviewing the literature on soft power in Asia, and Japanese cultural integration policies, the essay examines three cases of Japanese educational soft power - the JET Programme, the caregiver-training program, and internationalization of university programs. In addition, the essay shows that Japan is more successful attracting higher educated individuals seeking higher paying employment rather than skilled labor through these programs.