• 한국군사과학기술학회지
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• 제8권4호
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• pp.14-23
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• 2005

In this paper we propose a sensor fusion method for the navigation algorithm which can be used to estimate state vectors such as position and velocity for its motion control using multi-sensor output measurements. The output measurement we will use in estimating the state is a series of known multi-sensor asynchronous outputs with measurement noise. This paper investigates the Extended Kalman Filtering method to merge asynchronous heading, heading rate, velocity of DVL, and SSBL information to produce a single state vector. Different complexity of Kalman Filter, with. biases and measurement noise, are investigated with theoretically data from MOERI's SAUV. All levels of complexity of the Kalman Filters are shown to be much more close and smooth to real trajectories then the basic underwater acoustic navigation system commonly used aboard underwater vehicle.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.204-207
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• 2007

Film bulk acoustic wave resonator (FBAR) technology has attracted a great attention as a promising technology to fabricate the next-generation RF filters mainly because the FBAR technology can be integrated with current Si processing. The RF filters are basically composed of several FBAR devices connected in parallel and in series, and their characteristics depend highly on the FBAR device characteristics. Thus, it is important to design high quality FBAR devices by device or process optimization. This kind of effort may enhance the FBAR device characteristics, eventually leading to FBAR filters of high performance. In this paper, we describe the methods to more effectively improve the resonance characteristics of the FBAR devices.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권9호
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• pp.615-621
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• 2004

This paper describes the design of a 2-phase stepping motor driver using CPLD. The driver IC such as L297, which is mostly used has some difficulties in PWM current control because of the switching noise of power MOSFETs. The switching noise causes current ripple and acoustic noise. To reduce the switching noise, we designed a digital filter using VHDL. Also we designed constant current method for 1-2 phase(half step) excitation to reduce the torque ripple. Experimental results show the effectiveness of the proposed method. It is enabling further enhancements of stepping motor drive technology broadening the range of applications for the stepping motors.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.175-175
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• 2000

In this Paper we propose a navigation algorithm which can be used to estimate state vectors such as position and velocity for its motion control using multi-sensor output measurements. The output measurement we will use in estimating the state is a series of known multi-sensor asynchronous outputs with measurement noise. This paper investigates the Extended Kalman Filtering method to merge asynchronous heading, heading rate, velocity of DVL, and SSBL information to produce a single state vector. Different complexity of Kalman Filter, with biases and measurement noise, are investigated with theoretically data from KRISO's AUV. All levels of complexity of the Kalman Filters are shown to be much more close and smooth to real trajectories then the basic underwater acoustic navigation system comment)'used aboard underwater vehicle.

• 한국소음진동공학회논문집
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• 제17권10호
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• pp.983-992
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• 2007

It was proposed to identify Thiele Small Parameters for loudspeaker attached to closed-box using known dynamic mass of moving parts. Also, enhanced PSPICE circuit model for closed-box loudspeaker system was proposed to more accurately simulate real closed-box loudspeaker system. Frequency dependent parameters were used to model voice coil inductor. Acoustic pressure response curves and electrical impedance curves were simulated and investigated by PSPICE circuit model according to compensation filter's parameters. Finally, proposed method is expected to be utilized for identification of pseudo Thiele Small parameters of microspeaker.

• 한국자동차공학회논문집
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• 제3권6호
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• pp.23-29
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• 1995

In this study, Active noise controlis implemented with single channel and multi-channel adaptive algorithm in 3 dimensional reverberant enclosure sound. field, which occurrs in complicated acoustic mode. First, for the one case excited with the resonant frequency of an enclosure, a target of control and the other cases excited with band-pass filtered random noise(100~400Hz), it is implemented to control reducing interior noise of enclosure with single channel and realtime multi-channel adaptive algorithm for global noise reduction in enclosure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2066-2068
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• 1999

In this paper, an optical fiber sensor(OF sensor) utilizing the principal of Sagnac interferometer was proposed to detect the discharge signals which generated from needle-sphere electrode system in insulating oil. The performance of OF sensor was checked by sinusoidal calibration signal generated by PZT acuator at 198kHz. The detected discharge signals consisted of acoustic signal and the electrical noise. The noise signal could be removed by digital low pass filter. It was demonstrated that the OF sensor in this research had a possibility to detect the discharge signals in power apparatus.

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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• pp.152-153
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• 2001

파장 가변형 광 필터와 파장 선택형 광 스위치는 파장분할다중 광통신 및 광 교환 시스템을 구현하는데 매우 중요한 소자들 중의 하나이다. 특히 음향광학효과를 이용한 파장 가변형 광 필터(AOTF ： Acousto-Optic Tunable Filter)는 150nm 이상의 넓은 파장 가변범위, 1.5nm이하의 좁은 통과대역폭, 수 $\mu\textrm{s}$ 정도의 비교적 빠른 스위칭 속도 그리고 여러 개의 파장 채널을 동시에 선택할 수 있는 장점들을 가지고 있지만, 한편으로 표면 음향파(SAW： Surface Acoustic Wave) 구동에 필요한 RF 파워와 부 모드 (sidelobe)가 비교적 크다는 단점 때문에 실용화에 많은 제약을 받아왔다. (중략)

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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• pp.154-155
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• 2001

파장가변 광 필터는 WDM 광전송 시스템에 필요로 하는 핵심 부품중의 하나이다. 특히 LiNbO$_3$의 음향광학효과를 이용하는 AOTF(Acousto-Optic Tunable Filter)는 150nm 이상의 파장 가변 범위, 1.5nm 이하의 파장 통과대역폭, 수 $\mu\textrm{s}$ 정도의 비교적 빠른 스위칭 속도, 그리고 여러 파장 채널을 동시에 선택할 수 있는 장점들을 보유하고 있음에도 불구하고 표면 음향파(SAW： SurFace Acoustic Wave) 구동에 필요한 RF 파워와 부 모드(sidelobe)가 비교적 크다는 단점 때문에 실용화에 많은 제약을 받아왔다. (중략)

• 대한의용생체공학회:의공학회지
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• 제6권1호
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• pp.5-12
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• 1985

In this paper Kalman filtering technique is applied to ultrasound signal to improve resolution capability, Ivhlch is in use of diagnostic imaging systems. The main advantage of Kalman filter algorithm for the analysis of reflected ultrasound signal is its recursive structure which can be easily adapted to tlme varing system. Because soft-tissues, such as liver, act as distributed acoustic low-pass filters which continually change the propagating pulse. tIne can put to practical use above advantage to find a suitable signal generallng model. In state-space description of the system, the 6th order system produces tl)e 1)esc spectral approximation to the source pulse As a result of spectrum analysis, 6th order estimator for two closely spaced ((p.5 mm) reflectors enhances resolution by 4dB-lOdB. By using this result, the possibility to detect even minute tumor is demonstrated.