• 전력전자학회논문지
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• 제6권1호
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• pp.74-81
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• 2001

스위치드 릴럭턴스 모터(이하 SRM) 구동을 위한 센서리스 설계는 노이즈에 민감하기 때문에 이에 대한 강인성과 신뢰성이 있어야 한다. SRM 구동시에 이들 성분은 소선호 전자회로와 함께 대전류 전력회로와 근접되어 전기적으로 노이즈 환경을 만든다. 또한, 쇄교 인덕턴스와 유한 커플링 캐패시턴스에 의해 어떤 저전압 전류와 전압 측정회로에 노이즈를 일으킬 수 있다. 노이즈를 포함한 전류와 전압은 센서리스 알고리즘의 입력 값으로 사용되기 때문에 위치추정에 대한 오차를 발생한다. 본 논문에서는 입력 노이즈에 대한 높은 강인성과 저항성을 기술하며 퍼지 논리 기반 회전자 위치 추정 알고리 즘과 관측기 모델이 입력 데이터의 오차를 줄이기 위해 사용하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.102-106
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• 2006

Community noise has been serious social issues in Korea. The community noise concerns on traffic, industrial and apartment complex noise. In industrial noise, construction, factory sectors are included. This paper summerizes the final report prepared for MOE in 2005 by authors. The new policy will be enforced beginning in 2006 with 5 year schedule. Details on the policy will be demonstrated at the presentation.

• 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.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권9호
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• pp.429-434
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• 2006

In this paper, detection based - adaptive windowed nonlinear filter(DB-AWNF) is proposed for removing salt-pepper noise in infrared image. This filter is composed of impulse detector and window-size-variable median filters. Impulse detector checks whether current pixel is impulse or not using range function and nonlinear location estimator. If impulse is detected, current pixel is filtered according to four kinds of local masks by use of median filter. If not, current pixel is delivered to output like identity filter. In Qualitative view, the proposed could have removed heavy corrupted noise up to 30% and reserved the details of image. In quantitative view, PSNR was measured. The proposed could have about 12-31[dB] more improved performance than those of median $(3{\times}3)$ filter and 13-29[dB] more improved performance than those of median $(5{\times}5)$ filter.

• Advances in environmental research
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• 제4권4호
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• pp.211-218
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• 2015

Traffic noise estimation models are useful in evaluation of the noise pollution in current circumstances. They are helpful tools for design and planning new roads and highways. Measurement of average traffic noise level is possible when traffic speed and volume are known. The objective of this study was to devise a model for prediction of highway traffic noise levels based on current traffic variables in Iran. The design of this model was to take the impact of traffic congestion into consideration and to be field tested. This study is a library research augmented by field study conducted on Saeedi Highway located south west of Tehran. The period for the field study lasted 5 days from 7-12 February, 2013. This study examined liner and non-liner methods in formulation of its model. Liner method without a fixed coefficient was the best fit for the intended model. The proposed model can serve as a decision making tool to estimate the impact of key influential factors on sound pressure levels in urban areas in Iran.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.447-451
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• 2006

Automobiles become indispensable to our lives of modern days, however, their abrupt increase causes environmental problems. Relevant regulations domestically and internationally, therefore, have been discussed and reinforced for tackling those problems. The current test methods such as ISO 362 which have been adopted in many countries need to be reviewed to be effective, considering the changes in automobile techniques and road conditions. This research is aimed at providing counter-plans for the expected new measures by analyzing both the current and new test methods.

• Nuclear Engineering and Technology
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• 제46권6호
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• pp.883-888
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• 2014

This work presents the influence of noise originating from the tube itself on the detectability and sizing accuracy for laboratory-induced outer diameter axial cracks in nuclear steam generator tubes. The variations of signal amplitude and phase angle of the same cracks were analyzed when increasing the signal-to-noise ratio of the tube itself from 9 to 18. It was experimentally verified that the detectability for small cracks was enhanced by increasing the signal-to-noise ratio. The phase angle also rotated to a value representing the actual position and depth of a crack when increasing the signal-to-noise ratio.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1343-1348
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• 2014

The low frequency noise in Silicon Nanowire Field Effect Transistors is analyzed by characterizing the gate electrode dependence on various geometrical parameters. It shows that gate electrodes have a strong impact in the flicker noise of Silicon Nanowire Field effect transistors. Optimization of gate electrode was done by comparing different performance metrics such a DIBL, SS, $I_{on}/I_{off}$ and fringing capacitance using TCAD simulations. Molybdenum based gate electrode showed significant improvement in terms of high drive current, Low DIBL and high $I_{on}/I_{off}$. The noise power sepctral density is reduced by characterizing the device at higher frequencies. Silicon Nanowire with Si3N4 spacer decreases the drain current spectral density which interms reduces the fringing fields there by decreasing the flicker noise.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.1062-1068
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• 2007

변압기 보호와 과전류를 막기 위한 목적으로 COS를 사용하고 있다. 그러나 COS 휴즈는 과전류가 흐르면 과부하에 의하여 용단되면서 강한 아크를 발생하여 공기 절연파괴를 일으킨다. 이러한 현상은 소음을 발생하면서 주변 거주자나 행인들에게 두려움을 준다. 그래서 실제 환경하에서 발생되는 소음을 시급히 정립할 필요가 있다. 본 논문은 COS 휴즈가 용단되면서 발생하는 충격성 소음의 특성을 파악하고 이러한 소음을 줄일 수 있는 방안을 제안한다.

• 한국소음진동공학회논문집
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• 제13권10호
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• pp.760-766
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• 2003

This paper is concerned with the eddy current damper which can be used to enhance the damping of the host structure. The operating principle of the eddy current damper is first explained in detail. The dynamic interaction between the magnets and the copper plate produces eddy current thus resulting in the damping force. By attaching the eddy current damper to the host structure, the damping of the total structure can be increased so that vibrations can be suppressed. The advantage of the eddy current damper is that it doesn't require any electronic devices and power supply The effect of the eddy current damper on the global dynamic characteristics of the structure is investigated by considering the cantilever with the eddy current damper. Experimental results show that the eddy current damper is an effective device for vibration suppression.