• The Journal of the Acoustical Society of Korea
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• v.40 no.4
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• pp.270-277
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• 2021

In the power ultrasound fields, the flange position for fixing the transducer is an important factor influencing on electro-mechanical efficiency of the transducer. We suggested a practical method that can determine the installation position of the flange for different resonance modes of the bolt-clamped type Langevin ultrasonic transducer. A semicircular wedge-shaped jig was manufactured and moved along the lateral surface of the transducer. The vibration characteristics were examined after a constant pressure was applied to the semicircular wedge-shaped jig. By observing the change of the input admittance of the transducer depending on the position of the pressure application, the optimum position for the flange installation could be determined. The resonant modes of the transducer were calculated by a Mason's equivalent circuit, and the particle velocity distribution for each resonance mode was calculated by a transmission line model. Since the optimum positions determined from an experimental result show a good correspondence with the node positions of the vibration modes calculated by the transmission line model, the validity of the suggested method was verified.

• Journal of Venture Innovation
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• v.1 no.1
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• pp.197-210
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• 2018

The purpose of this study is to analyze the relationship between the induction servicescape and the user satisfaction and repurchase intention about the restaurant tables embedded with the most advanced eco - friendly induction range. The main results of this study are as follows. The demographic characteristics of the respondents were 104 male respondents and 106 female respondents, with male - female ratio almost similar. The respondents' positions and responsibilities consisted of 68 restaurant representatives and 142 restaurant managers or persons in charge. The number of restaurants embedded with the induction ranges staffing 5 or more employees was 62.4%, which clearly showed that they were larger than the average restaurants(2.8 employees). The result of hypothesis testing by regression analysis showed that the restaurant's eco - friendly functional induction servicescape had a significant effect on user satisfaction, and ② the eco - friendly functional induction servicescape of the restaurant had a significant influence on repurchase intention. ③ The operation of the restaurant with the induction of the eco - friendly function of the restaurant. The satisfaction of the manager has a significant influence on the repurchase intention. Therefor, the hypothesis suggested in this study was adopted.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.2
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• pp.43-45
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• 2000

In this study, present a method for extracting the BJT 1/f noise model parameters fabricated by BICMOS process. From the geometric analysis of the Kf, we show that Kf is in inverse proportion to emitter area. And it is extracting that $K=0.8\times10_{-20}, A_f=2, \alpha=1$ values.