• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2883-2886
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• 2003

좋은 발성을 위하여 음성이 만들어지려면, 뇌의 언어중추의 명령에 의하여 신경망을 통하여 ‘호흡기관(폐와 흉곽. 호흡관련 근육들)’과 ‘발성기관(주로 후두 즉 성대)’ 그리고 ‘조음, 공명기관(인두, 구강 및 비강)’의 근육들이 유기적으로 작용하여야 한다. 이런 협력 체제에 문제가 생기면, 다양한 종류의 질환이 유발될 수 있다[1,2]. 현재 임상에서 음성 분석을 위해 사용되는 시스템은 대부분 성대의 진동을 측정하기 위해 stroboscopy, 전기성문파형검법 (EGG, electroglottography), 후두근전도 중의 한 방법과 음성 분석을 위한 분석 프로그램으로 구성되어 있다. 그러나, 발성은 호흡과 매우 밀접한 관계가 있어 음성, 성대의 진동, 호흡 관계를 종합적으로 관찰할 필요가 있다. 본 연구에서는 발성 시 성대 점막의 접촉 양상은 ECG 로 측정하며, 발성의 주 에너지원이 되는 호흡의 변화를 2 channel 인덕턴스 호흡감시 장치(RIP: repiratory inductive plethymography)를 이용하여 흉곽의 움직임과 상 복강의 움직임에 대하여 측정하며, 발성되는 음성은 마이크로폰을 통하여 측정하는 ‘EGG, 음성, 호흡 통합검사 장치’를 개발하였다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.79-87
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• 1996

A new method for recognizing and locating partially occluded or overlapped two-dimensional objects regardless of their size, translation, and rotation, is presented. Dominant points approximating occuluding contoures of objects are generated by finding local maxima of smoothed k-cosine function, and then used to guide the contour segment matching procedure. Primitives between the dominant points are produced by projecting the local contours onto the line between the dominant points. Robust classification of primitives. Which is crucial for reliable partial shape matching, is performed using adaptive resonance theory (ART2). The matched primitives having similar scale factors and rotation angles are detected in the hough space to identify the presence of the given model in the object scene. Finally the translation vector is estimated by minimizing the mean squred error of the matched contur segment pairs. This model-based matching algorithm may be used in diveerse factory automation applications since models can be added or changed simply by training ART2 adaptively without modifying the matching algorithm.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1528-1529
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• 2011

플라즈마 변수를 측정하기 위한 가장 일반적인 방법은 정전탐침(Langmuir Probe)을 이용하는 것이다. 정전탐침은 RF 플라즈마 내에 삽입될 경우 탐침의 전위가 플라즈마 전위에 의해 진동하여 탐침전류의 왜곡이 발생하여 정확한 플라즈마 변수 측정이 어렵다. 탐침 전위의 변동을 최소화하기 위해 임피던스가 큰 인덕터를 탐침 회로 내에 삽입한다. 본 연구에서는 자기 공명 주파수가 13.56MHz 근방의 인덕터 3종류를 선정하여 간단한 RF 보상 정전탐침을 제작하여 유도결합형 플라즈마의 특성을 측정하였다. RF 보상 정전탐침에 의해 구해진 플라즈마의 전자 온도 및 플라즈마 전위는 감소하며, 플라즈마의 전자 밀도는 증가함을 알 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.1
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• pp.73-78
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• 2008

A resistor network model for the horizontal AlInGaN LED was investigated, The parameters of the proposed model are extracted from the test dies and $350{\mu}m$ LED, The center of the P-area is the optimal position of a P-electrode by the simulation using the model. Also the optimal chip size of the LED for the new target current was investigated, Comparing the simulation and fabrication result, the errors for the forward voltage and the light power are average 0,02 V, 8 % respectively, So the proposed resistor network model with the linear forward voltage approximation and the exponential light power model are useful in the simulation for the horizontal AlInGaN LED.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.1
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• pp.19-24
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• 1992

The analysis of the resonant tunneling based on the exact solution of Schrodinger equations is performed in a single quantum well structure under applied bias. The transmittivity and the net tunneling current density are calculated with Airy function and the boundary conditions which is suggested by Bastard. The results are compared with those from other methods and boundary conditions. From the calculated J-V characteristics for the tunneling current, the dependence of the voltage location showing the first peak current on the various temperatures and Fermi level is investigated. In addition, the wave function within the structure is obtained and compared with that from the flat-potential model.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.1
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• pp.72-79
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• 1997

Most open magnetic resonance imaging systems have used the planar gradient coils whose inductances were minimized through the magnetic energy minimization procedure in the spatial frequency domain. Though the planar gradient coils have smaller inductance than conventional gradient coils, the planar gradient coils often suffer from their poor magnetic field linearity. Scaling the spatial frequencies of the current density function designed by the magnetic energy minimization, magnetic field linearity of the planar gradient coils can be greatly improved with small sacrifice of gradient coil inductance. We have found that the figure of merit of the planar gradient coils, defined by the gradient strength divided by the linearity error and the inductance, can be improved by proposed technique.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.1
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• pp.97-102
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• 1995

The ferromagnetic resonance properties of Mg ferrites which have various porosity grain size, and saturation magnetization are measured at one frequency. This allows a determination of the anisotropy field(Ha). The saturation magnetization multiplied by porosity is the resonance magnetic field. As the saturation magnetization increases, the linewidth decerases due to decrement of magnetic inhomogenity in sample. the porosity is a major factor broadening the linewidth for Mg ferrite when porosity is more thatn 6%, and the anisotropy field is dominant when porosity is less than 6%.

• Journal of the Korean Chemical Society
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• v.21 no.4
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• pp.270-275
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• 1977

A rate constant is deduced for the reaction of tert-butoxy radicals and trimethylsilane from the measurement of the phase shift between the modulated light source and the ESR signal of trimethylsilyl radical. The rate constant was found to $3{\times}10^{-2}M^{-1}{\cdot}sec^{-1}$ at $-50^{\circ}C$.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.525-528
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• 1999

Abstract - In this paper, a segmentation method for brain Magnetic Resonance(MR) image using region clustering technique with statistical distribution of gradient image and fuzzy rules is described. The brain MRI consists of gray matter and white matter, cerebrospinal fluid. But due to noise, overlap, vagueness, and various parameters, segmentation of MR image is a very difficult task. We use gradient information rather than intensity directly from the MR images and find appropriate thresholds for region classification using gradient approximation, rayleigh distribution function, region clustering, and merging techniques. And then, we propose the adaptive fuzzy rules in order to extract anatomical structures and diseases from brain MR image data. The experimental results shows that the proposed segmentation algorithm given better performance than traditional segmentation techniques.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.4
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• pp.27-32
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• 1997

In resonant tunneling diodes with the quantum well structure showing the negative differential resistance (NDR), it is essential to increase both the peak-to-valley current ratio (PVCR) and the peak current desnity ( $J_{p}$) for the accurate digital switching operation and the high output of the device. In this work, a resonant interband tunneling diode (RITD) with single quantum well structure, which is composed of I $n_{0.47}$As/I $n_{0.52}$A $l_{0.48}$As heterojunction on the InP substrate, is fabricated ot improve PVCR and JP, and then the dependence of I-V charcteristics on the width of the quantum well was investigated.d.ted.d.