• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2505-2507
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• 1999

This paper presents novel self excited DC-DC converters such as Buck-boost type, Buck type and also non-inverting Buck-boost type. The proposed converters has the following advantages: simple topology, small number of circuit components, easy control methode. Therefore, these converters are suitable for the portable appliances with battery source. Theoretical analysis and experimental results for SOW class Buck-boost type self oscillation DC-DC converter have been obtained, which demonstrate the high efficiency and good performance.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.179-181
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• 1987

In this paper, a self-tuning controller design is proposed by using pole-zero placement method and considering a system time delay. To got better tracking for the generalized self-tuning controller, pole placement method for the closed loop system and zero placement method for the error transfer function are Introduced. The proposed method shows better efficiency than pole placement method for minimizing tracking error. Simulation gives good results in tie reference signal tracking.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1366-1369
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• 1993

This paper presents a simulation study on two self-learning control systems for a fuzzy prediction model of CO (carbon monoxide) concentration:linear control and fuzzy control. The self-learning control systems are realized by using Widrow-Hoff learning rule which is a basic learning method in neural networks. Simulation results show that the learning efficiency of fuzzy controller is superior to that of linear controller.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.168-172
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• 2014

A new sustain driving method is proposed to improve luminous efficiency by the generation of the self-erasing discharge during a sustain period in AC plasma display panel. As one subfield time in the conventional AC PDP is divided into the reset, address, and sustain period. Among them, as the square sustain waveform is alternately applied to the X and Y electrodes on the front plate during the sustain period, the plasma discharge for displaying the image is continuously produced. Meanwhile, in the conventional driving method, the address waveform applied to the A electrode on the rear plate is only driving during an address period and grounded during a sustain period. In this experiment, the negative pulse is applied to the A electrode at the latter part of the sustain pulse for improving the luminous efficiency producing the self-erasing discharge during the sustain period. The negative pulse on the A electrode can change from the space to the wall charge and induce the additional discharge by the accumulated wall charge when the voltages of three electrodes are grounded. As a result, the luminous efficiency will be measured with changes in the voltage level of the A electrode and the new driving method can be improved to the luminous efficiency about 32 % compared with the conventional driving method.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.763-771
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• 2006

This study was conducted to suggest effective alternatives for human resource management in the foodservice industry by investigating the influence of social exchange on employee empowerment and organizational efficiency, The findings derived from the study are as follows: First, the major components of social exchange, organizational support and the leader-member exchange (LMX), significantly influenced the components of employee empowerment such as signification and self-determination. Secondly, we found that signification and self-determination had a significant impact on the turnover intentions and organizational commitment of the employees, which in turn organizational efficiency. Thirdly, both the employees' turnover intentions and organizational commitment were significantly influenced by the organizational support and the leader-member exchange. These results suggest that it is necessary to have active communication between organizational leaders and members to improve employee empowerment. In other words, employees should acknowledge the meaning and importance of their tasks and support at the organizational level should be provided to ensure employee empowerment.

• The Research Journal of the Costume Culture
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• v.11 no.6
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• pp.913-924
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• 2003

The purpose of this study was to investigate the correlation between self-concept, clothing attitude and clothing buying behavior. The subjects used for the study were 300 male and female college students. The results of the study were as follows. The self-concept of subjects were identified four types(self-confident, positive to self, self-convinced and pessimistic). Self-confident type had the highest scores on self-concept and pessimistic type was the opposite. The clothing attitude was classified into 5 types(rational coordinative, clothing concerned, frugal, clothing showy and others conscious). Rational coordinative type and clothing concerned type were regarded more importantly than other types. The clothing buying behavior was emerged 5 types(economical, diffident, pleasure-seeking, impulsive and name-brand preferred). An economical efficiency was the most important factor in clothing buying behavior. The results of correlation between self-concept and clothing attitude showed that person who has more positive self-concept tends to have more interest and satisfaction toward clothing as well as tendency of showing off and rational coordination. The correlation between clothing attitude and clothing buying behavior showed that person who is more conscious to others tends to have more preference for name-brand products.

• Korean Journal of Childcare and Education
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• v.14 no.6
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• pp.171-185
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• 2018

Objective: This study aimed to investigate the influence of child care center managers' coaching leadership on teachers' motivational self-concepts via middle managers' coaching leadership. Teachers' motivational self-concepts consisted of personal self-concept and social self-concept. Methods: A questionnaire survey was conducted on 475 child care center teachers regarding teachers' recognition of the coaching leadership of managers and middle managers and motivational self-concepts of teachers. To analyze the collected data, the path was examined through descriptive statistics, correlation analysis, structural analysis using Amos, and the mediating effect was confirmed by conducting the Sobel Test. Results: The middle manager's coaching leadership was found to mediate the pathways from the manager's coaching leadership to the teacher's social self-concept, but did not mediate the personal self-concept of teachers. Conclusion/Implications: This study showed that the manager's coaching leadership was mediated by the middle manager's coaching leadership and that the manager's coaching leadership had an influence on the social self-concept of teachers. These results imply that both managers and middle managers need to develop coaching leadership skills in order to improve the motivational self-concept of teachers, which is important for work efficiency at child care centers.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.93-96
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• 2001

Structural polymer composites are susceptible to damage in the form of cracks, which form deep within the structure where detection is difficult and repair is almost impossible. A recent methodology for the damage repair of polymer composites using the self-healing technique is reported. The polymerization of the healing agent is triggered by contact with an embedded catalyst, being necessary to damage repair of polymer composites. For this purpose, the self-healing concept is introduced and the manufacturing process of microcapsule with the healing agent is briefly described. The polymerization between the healing agent and the catalyst is verified by the use of ESEM and IR spectroscopy. Finally the efficiency of the self-healing technique is investigated by measuring the critical load of TDCB specimen.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.3
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• pp.305-314
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• 2014

A pilot plant (Q=5 $m^3/d$) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water. Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.248-255
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• 2004

For the compactness of regenerative combustion, self regenerative combustion and embedding regenerator inside furnace are proposed. The Self Regenerative burner system was developed to enhance thermal efficiency and Low Nox emission. In the twin regenerative system, two burner heads are generally used for preheating and exhausting combustion mode. But self regenerative burner system use only single nozzle body for regenerative combustion. Also two kind of regenerator, internal and external type, were designed to operate conveniently in both large and small furnace. According to test result, the self regenerative combustion system gives strong internal exhaust gas recirculation that reduce NOx emission significantly. NOx was measured as 50ppm(5% O2, 1290C furnace temperature). Also it is found that the fuel saving rate due to the self regenerative burner system reach to 30-40%. Thus it can be concluded that self regenerative mild combustion system appears to provide a reasonable regenerative burner for compactness and high performance as compared with conventional twin regenerative burner system. Also in the RT Application , compact twin regenerative burner was developed with the help of embedding regenerator inside furnace.