• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.63-69
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• 1998

A new current controlled PWM technique with NPC structure is proposed in this paper. A current controlled PWM technique with neutral-point-clamped pulse-width modulation inverter composed of main switching devices which operates as switch for PWM and auxiliary switching devices to clamp the output terminal potential to the neutral point potential is described. The proposed current controller has a first and second current band. The switching pattern will be made by the first current band. According to the second current band, the output state of the switching pattern is changed into positive and negative state. This inverter output contains less harmonic content and lower switching frequency than that of conventional current controlled PWM technique at the same current limit. Two inverters are compared analytically and the performance is investigated by the computer simulation.

• Journal of the Korean Home Economics Association
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• v.40 no.11
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• pp.55-69
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• 2002

The purpose of this study is to examine the gender differences in the level of work/family spillover and factors explaining the spillover. Data are gathered from 1,236 Korean men and women aged between 30 to 59, using the structured questionnaire. The main results of this study are as follows. First, both men and women perceive moderate levels of negative and positive spillover from work to family. Second, the levels of negative family to work spillover are higher than then of positive family to work spillover. Third, men report higher levels of positive family to work spillover, but lower levels of negative family to work spillover than women. Sander differences in the levels of negative and positive spillover from work to family are not found. Fourth, only job characteristic factors are associated with four types of spillover of women, while the level of household labor sharing and spousal support are associated with work family spillover of men. Band on these findings, theoretical implications in terms of work-family research and gender norms are discussed.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.93-103
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• 2021

Purpose : This study aimed to investigate the effect of trunk postural stability maintained wearing a spiral elastic band on the upper extremity function of patients with stroke who undertook a functional activity program and to provide fundamental data useful for the application of therapeutic interventions in the clinical environment of occupational therapy. Methods : The research subjects included 16 patients with stroke who were evenly divided into an experimental group and a control group. The eight-week intervention consisted of a functional activity program aimed at improving the function of the affected-side upper extremity. The experimental group performed the functional activity program while maintaining a stable trunk posture by wearing a spiral elastic band. The control group followed the program without wearing the band. Upper extremity function was assessed before and after the intervention using a manual function test (MFT) and a motor activity log (MAL), and the effectiveness on the upper extremity function of the affected side was confirmed. Results : First, in the within-group comparison of the upper extremity function scores before and after the intervention, the experimental group showed a statistically significant difference in the MFT and MAL assessment(p<.05). The control group showed a statistically significant difference in the MAL assessment(p<.05). Second, in the between-group comparison of the change in scores after the intervention, a statistically significant difference was observed between the two groups in all assessments(p<.05). Conclusion : This study confirmed the positive effect on upper extremity function of trunk stabilization posture using a spiral elastic band. The results could be useful when implementing a task-oriented training program in the clinical environment of occupational therapy in the future, as application of the training while maintaining trunk postural stability by wearing a spiral elastic band could be more effective for improving the upper extremity function of patients with stroke.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.581-582
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• 2005

In order to apply the discharge plasma processing. to industrial areas, the control of the chemical reaction mechanism is necessary. The hybrid plasma reactor was designed for the effective treatment of wastewater and hazardous volatile organic substances. This plasma reactor was similar to the barrier discharge, and surface discharge on the dielectric surface was propagated to the water surface strongly for the heterogeneous chemical reaction at the interface between the working gas and the water surface. The discharge emission in this discharge reactor was mainly $N_2$ second positive band in the case of $N_2$ or air gas atmosphere, and intensities from OH radicals in Ar gas atmosphere were stronger than in $N_2$ or air gas atmosphere. From this result, it is necessary to apply Ar gas for the effective generation of OH radicals in this plasma reactor.

• Journal of KSNVE
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• v.7 no.6
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• pp.1007-1013
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• 1997

This paper presents active vibration control scheme of multi-mode forced vibration using piezocetamic sensors and actuators. The control scheme adopted is the Positive Position Feedback (PPF) control. Among various vibration control techniques. PPF control technique makes use of generalized displacement measurements to accomplish the vibration suppression. Two independent controllers are implemented to control the first and the second modes of the beam under external excitation. Experimental results for various damping ratios and feedback gains of the PPF controllers are compared with respect to the contorl efficiency. The results indicate that steady state vibration under wide band excitation can be controlled effectively when multiple sets of PZT sensors and actuators were used with PPF control technique.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.12
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• pp.716-722
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• 2005

In this paper, we propose the audio watermarking algorithm based on the critical band of HAS(human auditory system) without audibly affecting the quality of the watermarked audio and implement the detecting algorithm on the BSS(broadcast synchronizing system) for testing the proposed algorithm. According to the audio quality test, the SNR(signal to noise ratio) of the watermarked audio objectively is 66dB above. In the robustness test, the proposed algorithm can detect the watermark more than $90\%$ from various compression(MP3, AAC), A/D and D/A conversions, sampling rate conversions and especially asynchronizing attacks. The BSS automatically switches the programs between the key station and the local station in broadcasting system. The result of reliability test of implemented system by using the real broadcasting audio has no false positive error during 30 days. Because of detecting once processing per 0.5 second, we can judge that the false positive error does not occur.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.159-166
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• 2013

The primary objectives of this study were to identify who is happier in workplace. To do this, this study proposed and analyzed a theoretical model consisting of demographic factors such as sex differences, age band, marital status, child quantity, religion, education level, position, job, income etc, psychological factors such as extroversion, neurosis, positive belief and happiness level. The major results of analysis reveal that first, both demographic factors and psychological factors have a positive effect on the happiness level of office-worker. Second, child quantity, neurosis and positive belief is an important factors in predicting office-worker's happiness. In conclusion, the implication of our research is to verify factors to promote the happiness level of office workers.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.525-535
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• 2016

The purpose of this study was to evaluate the effect of thoracic dynamic stretching with elastic band on the ROM and ball speed for baseball player. For this purpose, 11 baseball players of the I city high school and university performed thoracic dynamic stretching with elastic band before throwing a ball. After stretching, we measured the ROM and ball speed and compared. The results were as follows. First, ROM after stretching showed a significant increase immediately compared with before stretching. Second, the speed of the ball was significantly increased after stretching compared with before. These results indicated that thoracic dynamic stretching with elastic band for baseball players might have a positive effect on ball speed as well as ROM.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.489-497
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• 2016

The purpose of this study is to examine the effect of milk protein intake and band exercise on active fitness and metabolism risk factor of elderly women for 8 weeks. The two groups were classified into one group(TG) with milk protein intake and band exercise both, and the other group(CG) that was controled. The group of TG was applied doing milk protein intake 3 times for a day, and doing band exercise 4 times for 60 minutes a week. The intensity of the exercise was RPE<17. Each measurement variable was measured before and after 8 weeks to investigate the effect. This study got the result with this step. First, TG has shown small interaction with active fitness. Second, TG has shown small interaction with metabolism risk factor. Therefore, this study gives us the positive result of the effect of milk protein intake and band exercise on active fitness and metabolism risk factor of elderly women for 8 weeks. However, it has limitation to verify effect of milk protein intake and band exercise.

• Journal of the Korean Institute of Gas
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• v.13 no.1
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• pp.9-13
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• 2009

A cause of noise and vibration which come from a Combustion of gas heater are a combustion roar and Combustion oscillation. A character of a combustion roar is that sound pressure is distribute with broad band frequency. otherwise, The presence of combustion oscillation caused by positive Feed Back in Combustion Chamber break out a noise and vibration. Accordingly, The method that be solved a noise and vibration is to make each natural frequency different frequency. first, in order to solve problem, we control ratio of fuel and air. that is, Keep away resonance. second, in order to changing natural frequency of Combustion Chamber, We changed the shape of Economizer.