• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.187-190
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• 2004

Transducer for ultrasonic linear motor with the symmetric and anti-symmetric modes was studied. The ultrasonic liner motor consists of two Lngevin type piezoelectric vibrators that cross at right angles with each other in tip. In order to excite symmetric and anti-symmetric mode, the transducer must have a 90 degree phase difference of voltage. Therefore, the tip of transducer moves on an elliptical motion. In this paper, the finite element analysis was used. The ultrasonic motor was fabricated using the simulated result and the driving characteristics were measured.

• 대한기계학회논문집A
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• 제30권3호
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• pp.342-348
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• 2006

A new magnetostrictive patch array transducer for the generation and detection of torsional waves is developed fur the on-line health monitoring of rotating shafts. Even though the torsional wave is useful in nondestructive evaluation due to its non-dispersive property, a transducer generating torsional waves in rotating shafts has not been developed so far. In this research, a torsional wave transducer using the magnetostrictive effect is newly developed. By bonding an away of magnetostrictive rectangular patches on the outer surface of the shaft at an oblique angle of $45^{\circ}$ and encircling the array by a solenoid coil, we have successfully generated and measured torsional waves by the developed transducer. Several experiments were carried out to check the transducer performance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.1053-1058
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• 2003

Piezoelectric under water acoustic transducer is a kind of device for under water detection working as not only an actuator but also a sensor. The technique that can predict acoustical characteristics of transducer is important for robust design of transducer in harsh underwater environment. This paper represents the development of software for analyzing dynamic characteristics of piezoelectric acoustic transducers based on finite element method. Modal and transient analysis modulo for acoustic transducers are developed TWO dimensional model for Tonpilz transducer is used for the test of the developed nodal and transient analysis modules. and comparison is made with a commercial code, ANSYS.

• 대한방사선기술학회지:방사선기술과학
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• 제23권2호
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• pp.33-37
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• 2000

The authors fabricated ultrasonic transducer with PVDF[poly(vinylidene fluoride)] piezoelectric polymer film. When impulse waves were applied to the PVDF ultrasonic transducer, the dependence of the response properties on the backing material with copper was investigated through not only theoretical calculations using Mason's equivalent circuit but also experimental measurements. The experimental pulse response properties agree with those of the theoretical calculations and the pulses were shorter than those for a PZT transducer. If such short-pulse properties are used in an medical ultrasonic image diagnosis apparatus, the resolution of the apparatus will be improved. When the insertion loss was calculated theoretically to the PVDF ultrasonic transducer, the frequency characteristics of its showed wideband frequency.

• 비파괴검사학회지
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• 제13권3호
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• pp.14-23
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• 1993

가시화 시험을 통하여 시험편에 부착된 초음파 진동자의 공진주파수의 측정을 시도하였다. 그 결과 시험편에 부착되어 있는 진동자의 공진주파수는 진동자 자체만의 공칭 공진주파수 보다 훨씬 낮게 나타났고, 그 정도는 주파수가 높은 진동자일수록 심하게 나타나는 것을 볼 수 있었는데, 이론적인 해석에 의한 검증 결과 그 원인이 진동자 보호용 알루미늄 판재의 공진에 의한 것으로 판명되었다.

• 한국전기전자재료학회논문지
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• 제14권9호
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• pp.744-750
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• 2001

Higher directivity acoustic transducer using the self-demodulation effect was fabricated. The structure of transducer was designed such as dimension and support type of the piezoelectric element, the vibrating metal plate, and the housing case. Based on the design, the transducer was fabricated and measured its acoustic characteristics. Also, AM modulated driving circuit was designed for using the self-demodulation effect. The piezoelectric sounder with 200kHz resonant frequency and 20kHz bandwidth was designed by considering the sharp directivity and the sound pressure. The design and fabrication method worked in this study can be utilized in development of various speakers with higher directivity and broader bandwidth.

• Smart Structures and Systems
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• 제17권2호
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• pp.313-325
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• 2016

The paper provides a comprehensive procedure for the mechanical and magnetic design of Langevin transducer based on giant magnetostrictive material. The the transducer is designed to work at its second mode of vibration, having high mechanical quality factor and low damping coefficient. The design procedure is based on an analytical model and it is verified by finite-element analysis. Experimental tests based on impedance response analysis in first and second modes are carried out on the prototype. Results confirm the appropriate design of this transducer, demonstrating the highest mechanical quality factor between the resonant transducers in the literature.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.427-432
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• 2003

The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of moter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for meter torque of programmable dynamometer. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction meter. Therefore, the torque controller is not affected by a load torque disturbance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1108-1110
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• 2003

The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of meter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for meter torque of programmable dynamometer. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction moter. Therefore, the torque controller is not affected by a load torque disturbance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.703-706
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• 2000

The acoustic characteristics radiated from the acoustic transducer with metal-piezoceramic laminated circular plate were simulated. The Vibrational modes of metal-piezoceramic laminated circular plates were calculated by using the finite element method. After meshing the inside closed boundary of the acoustic transducer, the pressure gradients and the isotaric lines were calculated for the various frequencies. It has been observed that the characteristics of the sound pressure calculated for the various frequencies. Also, the directivity patterns and the sound pressure radiated from the acoustic transducer were calculated by 2-dimensional analysis.