• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.144-145
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• 2000

비선형 감수율은, 비선형 광학 현상을 기술하는 중요한 특성값으로서, 비선형 광학 연구가 시작된 이래 지속적으로 많은 관심을 받아 왔다. 그러나 연구의 주된 범위가 2차 비선형 감수율 $\chi$$^{(2)}$ 와 그 응용에 집중되어 왔으며, 고차 비선형 감수율이 큰 물질의 부족으로 인해, 고차 비선형 광학 효과를 얻기 위하여 직접적인 고차 과정을 이용하기 보다 그림 1(a)와 같이 2차 비선형 광학 효과의 연속적인 과정을 통해 구현하는 방법이 선호되어, 비선형 감수율의 일반적인 특성에 대해서는 충분한 이해가 이루어지지 못하였다. (중략)

• Korean Journal of Optics and Photonics
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• v.9 no.2
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• pp.92-95
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• 1998

In this paper, we have shown theoretically that a nonlinear etalon with nonlinear mirrors exhibits optical bistability. It can be swithed with less power than a nonlinear etalon with linear mirrors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.197-205
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• 2000

The back-off input power level method is generally used for design of high linear mixer. In this paper, the predistortive mixer design method which attaches the predistortor in front of mixer is proposed to compensate the nonlinear characteristics of mixer and the predistortor has inverse nonlinear characteristics of mixer. The proposed method improves C/I ratio of mixer by 22 dB (@Po=-20 dBm/tone), 21.7 dB(@Po=-17 dBm/tone) with two tones of RF at 1852.5MHz, 1857.5MHz and LO at 2015MHz, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.479-486
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• 1999

In this paper the system performance degradation resulting from nonlinear transmitter power amplifier which is essential to increase the efficiency is analyzed in a forward link CDMA system. The power amplifier is modeled by power series model which includes only odd-order terms. The effects of power amplifier's nonlinearity such as intersymbol interference, phase distortion on the RF system performance were visualized by examining the distorted time domain waveforms, signal vector constellation. And through the investigation of the power spectrum density of the transmitted signal, spectral regrowth or sideband regrowth which is result from amplitude distortion can be seen. All these characteristics result in BER performance degradation due to other user interferences and intersymbol interference. The analysis technique described here applies not only to power amplifier but also to any other nonlinear components such as mixers and switches. Also the effects of adjacent channel interference and supurious emission can be analysed between different systems.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.20-21
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• 2000

광을 기반으로 한 논리 연산은 전자 소자의 속도 한계 및 연산 용량의 한계를 극복할 대안으로 많은 관심을 끌고 있다. 초고속 전광 논리 연산의 구현은 대부분 물질의 비선형성을 이용하며 특히 광섬유의 비선형 Ken 효과를 이용한 Sagnac 간섭계의 형태를 이용한 논리 연산이 주로 연구되어 왔다$^{(1)}$ . 그러나 광섬유의 비선형성을 이용하기 위해서는 충분히 큰 광 강도가 필요하며 회로 구성에 있어서도 크기가 크다는 단점이 있다. 최근에는 반도체 광증폭기의 비선형 이득 포화 현상을 이용한 TOAD 등이 발표되어 상대적으로 크기도 감소하고 사용되는 광 강도 역시 감소시킬 수 있었다$^{(2)}$ . 간섭계를 이용한 광논리의 구현은 Sagnac 간섭계 뿐만 아니라 비선형 특성을 갖는 도파로로 구성된 Mach-Zehnder 간섭계, Michelson 간섭계 등도 이용이 가능하다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.940-940
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• 2006

• Environmental and Resource Economics Review
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• v.23 no.3
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• pp.515-551
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• 2014

Recently, there has been a debate as to whether bioethanol should replace some portion of gasoline for fuels in South Korea, as energy security as well as climate change issues are rising as a significant national agenda. However, a considerable amount of subsidy will be required to compensate for the higher price of bioethanol-blended gasoline. In this context, government subsidy will obtain justification only when the positive social gains from consuming bioethanol for fuels can exceed the negative social costs. Through a nation-wide choice experimental survey, we examine if South Koreans have a positive value as well as non-linear preferences on substituting bioethanol for gasoline. The results reveal that the willingness to pay for purely domestic bioethanol-blended gasoline within 10% is about 52 KRW; Koreans have concave preferences on the blending ratio of bioethanol to gasoline. The turning point of the blending ratio of bioethanol was 6.5%. Also, we found inverse U-shaped curve between income and bioethanol choice probability and the turning point of the income was calculated as 250~299million KRW. Politically conservative propensity advocates uses of bioethanol blended gasoline, but awareness on bioethanol or more weights on environmental conservation have significantly negative effects on the choice of bioethanol. However, the design of the survey questionnaire is incompatible with the RFS of Korea and assumes orthogonality among the following four interrelated attributes: (i) domestic or offshore procurement of feedstocks in the case of domestic production, (ii) domestic production or import of bioethanol, (iii) the blending ratios, and (iv) the retail price increases. In addition, the results of model estimation and of model selection test are not definite. Hence, the results in this study should not be directly applied to the design of the specifics of the Korean RFS. Hence, the results in this study require cautions in applying to the design of the Korean RFS policy.

• Korean Journal of Optics and Photonics
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• v.6 no.2
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• pp.135-141
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• 1995

Phenomenological nonlinear gain saturation effect on the noise characteristics of a multi-electrode DBR laser, when the lasing wavelength changes continuously, is presented theoretically. Using the optical transmission line theory, noise characteristics reliant on output power are analyzed by taking into account both the spontaneous enhancement factor K due to the distribution of the spontaneous emission along the active cavity and the nonlinear gain saturation effect. Spontaneous emission rate was increased due to an increase in injected current into the passive section, which in turn lead to increase in relative intensity noise (RIN) and frequency noise. Phenomenological nonlinear gain saturation was found to have significant effect on RIN and frequency noise characteristics. However. Iinewidth was found to decrease due to a phenomenological nonlinear gain saturation effect. ffect.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.3
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• pp.492-498
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• 2000

When multi-carriers are applied to the high power amplifier(HPA) having nonlinear characteristics, the HPA output has unwanted IMD signals. The IMD signal is noise in the HPA. The magnitude and phase of the main and IMD signal of HPA output are changed as the input signal power is changed. If we know exactly the magnitude and phase characteristics of the main and IMD signal, we can design a more adequate linearizer and understand the characteristics of transistor. In this paper the magnitude and phase of the main and IMD signal of HPA output are measured and analyzed for variation of the input power.

• Korea journal of population studies
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• v.23 no.1
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• pp.197-215
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• 2000

이 논문에서는 선형·비선형 성장곡선모형의 종류와 특성을 살펴보고, 이들을 비교·검토하고, 모형선호기준 통계량에 입각하여 추정결과를 비교한다. 또한 최종사용자 환경을 위한 SAS/AF로 구현한 성장곡선모형에 의한 인구예측시스템을 소개한다.