• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.294-298
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• 2003

In this paper, the new zero-current-transition (ZCT) circuit cell is proposed. The main switch is turned-off under the zero current and zero voltage condition, and there is no additional current stress and voltage stress in, the main switch and the main diode. The Auxiliary switch is turned-off under the zero voltage condition, and the main diode is turned-on under the zero voltage condition, The resonant current required to obtain the ZCT is small and regenerated to the input voltage source. The operational principles of the boost converter integrated with the proposed ZCT circuit cell is analyzed theoretically and verified by the simulation and experimental result. Index terms - zero-current-transition (ZCT), zero-current- switching (ZCS), zero-voltage-switching (ZVS)

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.502-504
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• 2008

A new output inductor less phase shift full bridge converter with current reduction technique for server power application is proposed in this paper. The proposed converter can reduce the current stress by using the auxiliary circuit. Since the auxiliary circuit causes the additional resonance between the leakage inductor and auxiliary capacitor before the powering period, the proposed converter has lower current stress even no output filter inductor. Small size and circulating energy can be also the merits of the proposed converter. The operational principles and analysis are presented. Experimental results demonstrate that the current stress can be reduced effectively by using the auxiliary circuit without large output filter inductor.

• Journal of Power Electronics
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• v.3 no.4
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• pp.215-223
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• 2003

In this paper, a new zero-current-transition (ZCT) circuit cell is proposed. The main switch is turned-off under the zero current and zero voltage condition, and there is no additional current stress and voltage stress in the main switch and the main diode, respectively. The auxiliary switch is turned-off under the zero voltage condition, and the main diode is turned-on under the zero voltage condition. The resonant current required to obtain the ZCT condition is relatively small and regenerated to the input voltage source. The operational principles of a boost converter integrated with the proposed ZCT circuit cell are analyzed and verified by the simulation and experimental results.

• Journal of East-West Nursing Research
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• v.11 no.1
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• pp.65-74
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• 2005

This research has been conducted in order to compare and analyze the role-conflict, job stress and job satisfaction of nurses according to their current work posts. The subjects of this research were carefully selected 426 nurses from 2 university hospitals. The research tool were a role-conflict measurement index, job stress a tool, and job satisfaction Minnesota Satisfaction Questionnaire. The data have been collected using a structured questionnaire from March to May 2003. The collected data have been analyzed using the SPSS PC 10.0V program. The nurses at Intensive Care Unit (ICU) showed highest level of job stress while the nurses at surgical ward showed the lowest level of job stress (F=8.37, p=.000). There was no significant difference in role-conflict and job satisfaction according to the current work posts. According to the results of this research, there was a difference in stress according to the current work posts, and it turned out that the nurses at ICU had the highest level of stress compared to the nurses at other departments, and it causes a fall in job satisfaction.

• Molecules and Cells
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• v.47 no.1
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• pp.100006.1-100006.10
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• 2024

Nitric oxide (NO) serves as an evolutionarily conserved signaling molecule that plays an important role in a wide variety of cellular processes. Extensive studies in Drosophila melanogaster have revealed that NO signaling is required for development, physiology, and stress responses in many different types of cells. In neuronal cells, multiple NO signaling pathways appear to operate in different combinations to regulate learning and memory formation, synaptic transmission, selective synaptic connections, axon degeneration, and axon regrowth. During organ development, elevated NO signaling suppresses cell cycle progression, whereas downregulated NO leads to an increase in larval body size via modulation of hormone signaling. The most striking feature of the Drosophila NO synthase is that various stressors, such as neuropeptides, aberrant proteins, hypoxia, bacterial infection, and mechanical injury, can activate Drosophila NO synthase, initially regulating cellular physiology to enable cells to survive. However, under severe stress or pathophysiological conditions, high levels of NO promote regulated cell death and the development of neurodegenerative diseases. In this review, I highlight and discuss the current understanding of molecular mechanisms by which NO signaling regulates distinct cellular functions and behaviors.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.449-456
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• 2009

The RMS(Root Mean Square) current stress reduction technique for the PFC link capacitor is proposed. Although the various parameter is exist for optimizing the link capacitor, the RMS current stress is the most weighty practical parameter. The proposed C-L filter can reduce effectively the RMS current stress by filtering the output current. And with the C-L-L-C filter proposed in this paper, the more RMS current stress can be reduce because it filters not only the output current, like C-L filter, but also the input current of DC/DC stage. The proposed filter is simple to design and have no effect on the control part of the PFC because of the very low crossover frequency. To confirm the validity of proposed filter, theoretical analysis, the design guide, verification of experimental results are presented.

• The Journal of Industrial Distribution & Business
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• v.14 no.6
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• pp.9-16
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• 2023

Purpose: The relationship between employee consultations and job/workplace stress remains one of the most consequential owing to its impact on the well-being of the employees and their final output. The current study aims to look closely at the connection employee consultation and job stress, investigating the prior and present literature dataset to explore employee consultations' approaches, effects, and impacts in reducing job stress. Research design, data and methodology: The current research has conducted literature content analysis, and all collected prior studies were selected and screened thoroughly by the topic and keywords of the research. Results: The result of this study shows that meaningful consultations for workers are pertinent and essential in addressing the causes of workers' job stress, thus critical in reducing them as follows: Mitigation of Workers' Stressful Concerns, Booting Interpersonal Relationships at Work, Employees Personal Improvement, and Proper Communication Tendencies and Culture. Conclusions: All in all, this study concludes that employee consultation equally deals with positive aspects such as areas of strengths and achievements of employees. It entails discussing ways to maintain or consistently improve a worker's abilities and performance. Through the above dimensions, employee consultation reduces job stress and improves performance and outcomes.

• Journal of Power Electronics
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• v.1 no.2
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• pp.71-77
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• 2001

This paper proposes a new zero-current switching (ZCS) pulse-width modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero current condition. The diodes commutate softly and the reverse recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of DC to DC PWM converters is derived. The new family of ZCS PWM converters is suitable for the high power applications employing IGBTs. Among the new family of DC to DB PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5 kW prototype converter operating at 40 kHz.

• Journal of the Korean Home Economics Association
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• v.41 no.11
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• pp.95-111
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• 2003

The purpose of this study was to investigate the current trend of early education and to examine the relationship between the state of early education and maternal beliefs, stress, and achievement pressure. The subjects were 275 mothers of 4∼6 year-old children in Seoul. The main results were as follows : 1) Most of the subjects' children(87.6%) were involved in early education, especially in the form of home-visit study and study papers. 2) Parental beliefs (about child development and early education) and maternal achievement pressure were significantly related to the degree of actual involvement and perceived necessity of early education. 3) Parental stress regarding child's temperament was significantly related to the starting age of early education. But the other factors of parental stress had no significant relation to the state of early education.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.134-145
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• 2008

Objectives : This study investigated the relationship between drinking, smoking and stress of workers by analyzing heart rate variability. The subjects were workers in the automobile manufacturing industry. Methods : The subjects consisted of 21,239 and 19,999 industrial workers who had received health examination by Korean oriental medicine and submitted questionnaires about drinking history and smoking history, during 8 months from April to November. The subjects were categorized into drinking history and smoking history. The heart rate variability was measured for five minute at rest using SA-3000P (Medicore) and reported stress severity as stress index, stress resistance and fatigue. We analyzed the relationship between drinking, smoking and stress into frequencies, $x^2$-test using the SPSS Ver. 12.0. Results : Regarding the relationship between drinking and stress index orstress resistance, there was no statistically significant difference, but regarding the relationship between drinking and fatigue, the drinker group had a significantly higher level of fatigue than the non-drinker group. There was a statistically significant difference in stress index, stress resistance and fatigue between the current-smoker group and others. Stress resistance of the current-smoker group had lower levels than the non-smoker group or ex-smokers. On the other hand, stress index and fatigue of the current-smoker group had higher levels than the non-smoker group or ex-smokers. Conclusions : The above results revealed that drinking and smoking could put workers under a lot of stress. Smoking workers were especially apt to be under stress and had difficulty in alleviating stress.