• Journal of Power Electronics
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• v.11 no.3
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• pp.245-255
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• 2011

A novel single-stage AC/DC converter with the soft-switching characteristic based on interleaving technology and an LLC topology is proposed here. The converter is integrated by an interleaved cell and an LLC cell. Because the components of the system are reduced as a result of integrating, the cost decreases. Since interleaving technology is adopted, the converter can work in a high voltage input state. The LLC topology chosen here ensures that the switches on the primary side work in the ZVS condition and that the diodes on the secondary side work in the ZCS condition, which decreases the switching loss of the system. A theoretical analysis and the design procedures of the proposed converter are proposed and discussed in detail. Simulations and experimental studies with a 100W prototype are done to prove the analysis.

• Journal of the Korea Safety Management & Science
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• v.5 no.4
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• pp.13-20
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• 2003

The purpose of this study is to know the status of prevention on health obstacle in industries with confined space. Total 190 respondents, 95 safety or health managers and 95 confined space workers from 95 industries with confined space are surveyed by hygienists from April 2003, to July 2003. The contents of survey include health-work program in confined space, instrument of oxygen sampling, equipment of ventilation, safety and health education, watching manager, head count, awakening of risk, air condition and emergency training. The results are as follows: 1. It is found 38% of respondents established health-work program in confined space. The percentage of respondents with instrument of oxygen sampling and equipment of ventilation, operation of safety and health education, posting of watching man and operation of head count are 42%, 35%, 75%, 46% and 56%, respectively. 2. The percentage of awakening of risk, confirm of air condition and operation of emergency training are 36%, 25% and 15%, respectively.

• Tribology and Lubricants
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• v.14 no.2
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• pp.75-81
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• 1998

Condition monitoring technology was applied for an air compressor lubricating system to achieve a proactive maintenance, which could prevent a catastrophic failure and detect root causes of the conditional failure of the system. For this work, various types of wear monitoring technology were used and compared with the results of vibration and temperature measurements. The Results generally showed that every technology has a limitation to failure detection, and integrated-based condition monitoring should be performed for the best results. In this work, an idea for the implementing integrated wear monitoring was suggested and demonstrated.

• The Journal of Korean Medicine
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• v.34 no.1
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• pp.29-34
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• 2013

Objectives: This report aimed to demonstrate effect of human placental extract (HPE) pharmacopuncture in students suffering fatigue due to hard work and mental stress. Methods: Thirty-four college students, preparing for the final-term exam, received pharmacopuncture of HPE into Kwanwon (CV4) subcutaneously twice a week for 7 weeks. After every pharmacopuncture of HPE, degree of fatigue was surveyed by questionnaire including physical condition, physical endurance, concentration and memory. Results: Pharmacopuncture of HPE into CV4 gently improved physical condition, physical endurance, concentration and memory. Improvement of physical condition was especially positively correlated with the increasing number of pharmacopuncture of HPE into CV4 as confirmed by calculation of Pearson coefficient. Conclusions: Pharmacopuncture of HPE into CV4 alleviated fatigue in the students from hard work and mental stress.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.5
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• pp.523-529
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• 2009

Smart sensor is known as intelligent sensor, it is different with other conventional sensors in the case of intelligent system embedded on it. Smart sensor has many benefits e.g. low-cost in usage, self-decision and self-diagnosis abilities. This sensor consists of perception element(sensing element), signal processing and technology of communication. In this work, a bridge and structure of smart sensor has been investigated to be capable to condition monitoring routine. This investigation involves low power consumption, software programming, fast data acquisition ability, and authoritativeness warranty. Moreover, this work also develops smart sensor to be capable to perform high sampling rate, high resolution of ADC, high memory capacity, and good communication for data transfer. The result shows that the developed smart sensor is promising to be applied to various industrial fields.

• Journal of Power System Engineering
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• v.14 no.4
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• pp.5-10
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• 2010

This study was investigated the effect on operating characteristics of apparatus according to frosting and defrosting to develop of new defrosting equipment. The results showed as following. Frost was almost removed using the defrosting equipment with roll brush type that defrosting is possible under operating condition. Also, the temperature of compressor inlet, evaporator inlet and outlet showed higher value because of heat transfer resistance of cooling pipe frost comparing with defrosting condition. And the compressor work showed 10% lower and COP was presented 24% higher values than defrosting condition. Therefore, defrosting for cooling coil of refrigeration and low temperature storage was effected on operation and performance characteristics of equipment. This highly effects on real refrigeration apparatus which is operated in year-around.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.191-199
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• 1997

Condition monitoring technology was applied for an air compressor lubricating system to achieve a proactive maintenance, which could prevent a catastrophic failure and detect root causes of the conditional failure of the system. For this work, various types of wear monitoring technology were used and compared with the results of vibration and temperature measurements. Results generally showed that every technology has a limitation to failure detection, and integrated-based condition monitoring should be performed for the best results. In this work, an idea for the implementing integrated wear monitoring was suggested and demonstrated.

• Journal of The Korea Institute of Healthcare Architecture
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• v.12 no.1
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• pp.41-48
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• 2006

The purpose of this study is to find Healing elements in the late work of Frank Lloyd Wright. Healing elements are mainly composed of physical, social and psychological functions, which are clearly reflected in holistic attitude and intuition in his Organic theory of Architecture. Late works of Wright since 1935 show particularly shapes of triangle and circle creating the emotional images associated with Hope and Infinity. His image-oriented design attitude is thought to be strongly related to the pursuit of Utopian ideal which means peaceful condition. He regarded it as the consequence of integrity and control, which could be thought as condition of Healing environment. Refuge and Prospect can be complementary elements of spatial expression representing peaceful and dynamic condition of the Nature itself. Five works selected in this case study have unique design ideas related to the function and image of Healing environment interpreted by the criteria of Refuge and Prospect.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.822-831
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• 2011

This study was to examine factors related to depression of female labor workers. In order to identify health promotion strategies and intervention program to reduce depression of female labor workers. The participants were 176 female workers of manufacturing industries. Data were collected using a structured questionnaire that consisted of personal characteristics, duty related, work related characteristics and depression. Using a SPSS/WIN 17.0 Program, descriptive statistics, $x^2$-test, ANOVA and Stepwise Multiple Regression procedures were employed. As follows on the results; In Correlation analysis, work intensity, work concentration, vibration, work difficulty and job stress were positively correlated with depression. In multiple Regression, work intensity and work difficulty were significantly explained by depression. Given the findings, Do nevertheless support the need to develop effective depression intervention programs to reduce factors which work related condition and depression.

• Journal of Korean Academy of Nursing
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• v.15 no.3
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• pp.39-49
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• 1985

The study was carried out to measure the degree of work stress among clinical nurses, and to identify factors influencing the work stress. Data was collected from 215 staff nurses working in the Seoul National University Hospital from the end of February to first of march, 1984. The results and suggestion of study were: 1. Nurses perception of work stress. 1) Mean score of total work stress of nurses was 4.467, when maximum score was 6. High degree of work stress is evident among nurses. 2) The highest rank of stress factor was inter-personal relationship with physicians, night duty, heavy work load, inadequate working condition and payment were other stress factors. 2. Relationships between situational variables and degree of stress. There was significant correlation-ship between nurse's total work stress score and educational levels (r=0.153, p=0.032).