• JSTS:Journal of Semiconductor Technology and Science
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• 제4권1호
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• pp.63-73
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• 2004

A simple analytical model has been presented for the study of the optical bistability using a $GaAs-Al_{0.32}Ga_{0.68}As$ multiple quantum well (MQW) p-i-n diode structure. The calculation of the optical absorption is based on a semi-emperical model which is accurately valid for a range of wells between 5 and 20 nm and the electric field F< 200kV/cm . The electric field dependent analytical expression for the responsivity is presented. An attempt has been made to derive the analytical relationship between the incident optical power ( $(P_{in})$ ) and the voltage V across the device when the diode is reverse biased by a power supply in series with a load resistor. The relationship between $P_{in}$ and $P_{out}$ (i.e. transmitted optical power) is also presented. Numerical results are presented for a typical case of well size $L_Z=10.5nm,\;barrier\;size\;L_B=9.5nm$ optical wave length l = 851.7nm and electric field F? 100kV/cm. It has been shown that for the values of $P_{in}$ within certain range, the device changes its state in such a way that corresponding to every value of $P_{in}$ , two stable states and one unstable state of V as well as of $P_{out}$ are obtained which shows the optically controlled bistable nature of the device.

• 전자공학회논문지A
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• 제30A권3호
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• pp.76-87
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• 1993

We present a self-consistent, 2-dimensional solution of the Poisson and Sch rodinger equation based on the finite difference method with a nonuniform mesh size for a AlGaAs/GaInAs/GaAs HEMT devide. During the interative self-consistent calculation, however, we calculate Schrodinger equation only a some region of device, not a fully region in order to save the moemory and the speed-up of computation, and then use the approximated data for the other region using by a interpolation method with a given values. Also we adopt the proper matrix transformation method that allows preservation of the symmetric, form of the discretized Schrodinger equation, even with the use of a nonumiform mesh size, therefor, can reduce the computation time. We calculate the wavefunction, eigenstates and the electron concentration uat channel layer nder the thermal equilibrium and the biased conditions, respectively. Also,these parameters are used to solve 2-dimensional tdistribution of potential in he entire region of device. It is proved that the method is very efficient in finding eigenstages extending over relatively large spatial area without loss of accuracy. So, it can be used rather easily in any sarbitrary modulation doped utucture.

• 한국정보통신학회논문지
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• 제12권7호
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• pp.1235-1242
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• 2008

본 논문에서는 $0.18{\mu}m$ triple-well CMOS 공정을 사용하여 포톤계수 방식의 $32{\times}32$ 픽셀 어레이를 갖는 CMOS ray 영상센서를 설계하였다. 설계된 영상센서의 카픽셀은 $100{\times}100\;{\mu}m2$ 면적을 가지고 있고 약 400개의 트랜지스터로 구성되어 있으며, 범프 본딩을 통해 ray 검출기와 CSA(Charge Sensitive Amplifier)의 연결을 위한 $50{\times}50{\mu}m2$의 오픈패드를 가지고 있다. 각각의 싱글픽셀 CSA에서 전압 바이어스 회로를 사용한 folded cascode CMOS OP amp 대신 레이아웃 면적을 줄이기 위하여 self biased folded cascode CMOS OP amp를 이용하였으며, 계수 모드 진입 전후에 CLK에서 발생 할 수 있는 short pulse를 제거하는 15bit LFSR 계수기 (Linear Feedback Shift Register Counter) 클럭 발생회로를 제안하였으며, 읽기 모드에서 CMOS X-ray 영상센서의 최대 전류를 줄이기 위하여 열 어드레스 디코더를 이용하여 한 열씩 읽도록 설계하였다.

• 전자공학회논문지B
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• 제33B권6호
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• pp.45-53
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• 1996

In this paper, the convergence behavior of timing phase when an adaptive partial response equalizer and decision-directed type of a PLL work together in a digital recording channel is described. The phenomena of getting biased in timing phase when the convergence parameter of an adaptive partial response equalizer and timing recovery constant of a PLL are not selected properly is introduced. The phenomena, occurring due to perturbation of timing phase, are analyzed, by computer simulation and the region of ocnvergence for timing phase is discussed. Also, a method to overcome the phenomena using a variable step-size parameter is described.

• 자원ㆍ환경경제연구
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• 제10권3호
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• pp.323-344
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• 2001

This study analyzes the relative efficiencies of three types of non-landfill treatment of food wastes; recycling to fertilizers or animal feeds, reducing the size of food wastes, and fermentation of food wastes. Unlike previous studies our study incorporates not only usual inputs and outputs but also emissions of pollutants such as odor and noise generated by the treatment facilities into the analysis. A nonparametric method suggested by Fare et al. (1989) has been used to estimate the relative efficiencies of facilities incorporating emission of pollutants. The results show that recycling is more efficient than the other two treatment methods. It is also shown that the usual models that do not incorporate the environmental aspects of the treatment facilities derive a biased conclusion on the relative efficiencies.

• 천문학회지
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• 제48권3호
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• pp.203-206
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• 2015

The masses of supermassive black holes in active galactic nuclei (AGN) can be derived spectroscopically via virial mass estimators based on selected broad optical/ultraviolet emission lines. These estimates commonly use the line width as a proxy for the gas speed and the monochromatic continuum luminosity, λL_λ, as a proxy for the radius of the broad line region. However, if the size of the broad line region scales with the bolometric AGN luminosity rather than λL_λ, mass estimates based on different emission lines will show a systematic discrepancy which is a function of the color of the AGN continuum. This has actually been observed in mass estimates based on Hα/Hβ and C_IV lines, indicating that AGN broad line regions indeed scale with bolometric luminosity. Given that this effect seems to have been overlooked as yet, currently used single-epoch mass estimates are likely to be biased.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.697-700
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• 1999

This Paper presents the design, fabrication, analysis of the measured date of a voltage controlled oscillator(VCO) for the application of Personal Communication Systems. Main VCO circuit consists of self biased emitter resonating circuit with microstrip line resonator on FR4 epoxy substrate. A varactor diode is used for 90MHz frequency tuning with center frequency of 1635MHz Phase noise of -114.67㏈C/Hz at 100KHz off set has been achieved with 3.3 V supply. The size of the fabricated VCO circuit is 1.25 cm$\times$ 1.25 cm.

• Communications for Statistical Applications and Methods
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• 제14권3호
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• pp.641-648
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• 2007

We propose the new sampling method, called modified ranked ordering set sampling (MROSS). Kim and Kim (2003) suggested the sign test using the ranked ordering set sampling (ROSS), and showed that the asymptotic relative efficiency (ARE) of ROSS against RSS for sign test increases as sample size does. We propose the estimator for the population mean using MROSS. The relative precision (RP) of estimator of the population mean using MROSS method with respect to the usual estimator using modified RSS is higher, and when the underlying distribution is skewed, the bias of the proposed estimator is smaller than that of several ranked set sampling estimators.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (3)
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• pp.451-453
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• 2004

NTSS(New Three-Step Search Algorithm)는 대표적인 Fast BMA(Block Matching 시gorithm)인 TSS(Three-Step Search Algorithm)에 중앙 편향적(Center-Biased) 특성을 고려하여 향상시킨 방법이다. 그러나 NTSS는 움직임이 작은 영상인 경우에는 TSS보다 개선된 성능을 보여주지만, 움직임이 큰 영상에 대해서는 TSS와 큰 차이가 없으며 탐색영역이 커질수록 오히려 성능이 떨어지는 단점이 있다. 본 논문에서는 움직임 벡터의 특성에 맞는 탐색영역을 적용시킴으로써 탐색영역의 증가로 발생되는 NTSS의 단점을 보완하여 움직임이 큰 영상에 대해서도 향상된 성능을 갖는 방법을 제안한다. 제안된 방법을 적용 하였을때 움직임이 작은 영상에서는 기존의 방법과 동등한 결과를 얻었으며 움직임이 큰 영상에서는 최고 0.5db이상 성능이 개선되었다.

• 말소리와 음성과학
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• 제7권3호
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• pp.55-64
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• 2015

Previous research on syntactic processing shows that the interpretation of a syntactically ambiguous sentence is frequently strongly biased towards one meaning over another. The current study investigated the effect of bias strength on the production of disambiguating prosody for English ambiguous sentences. In Experiment 1, 40 speakers gave default readings of 18 syntactically ambiguous sentences. Questioning was used to prove intended meanings behind default readings. Intended meanings were treated as interpretation biases when a majority of speakers read a sentence with the same intended meaning. The size of the majority was used to establish bias strength. In Experiment 2, 10 speakers were instructed to use prosody to disambiguate given alternate meanings of the sentences from Experiment 1. The results indicated an effect of bias strength on disambiguating prosody: speakers used temporal juncture cues to reliably disambiguate alternate meanings for sentences with a weak interpretation bias, but not for those with a strong bias. Overall, the results indicated that interpretation biases strongly affect the production of prosody.