• JSTS:Journal of Semiconductor Technology and Science
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• 제13권3호
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• pp.207-212
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• 2013

A new CMOS voltage-bias differential LC voltage-controlled oscillator (LC-VCO) with active source degeneration is proposed. The proposed degeneration technique preserves the quality factor of the LC-tank which leads to improvement in phase noise of VCO oscillators. The proposed VCO shows the high figure of merit (FOM) with large tuning range, low power, and small chip size compared to those of conventional voltage-bias differential LC-VCO. The proposed VCO implemented in 0.18-${\mu}m$ CMOS shows the phase noise of -118 dBc/Hz at 1 MHz offset oscillating at 5.03 GHz, tuning range of 12%, occupies 0.15 $mm^2$ of chip area while dissipating 1.44 mW from 0.8 V supply.

• Journal of the Korean Statistical Society
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• 제9권2호
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• pp.145-172
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• 1980

Draper and Lawrence (1965a) have given mixture designs for three factors when all the mixture components can vary on the entire factor space so that the region of interest is an equilateral triangle in two dimensions. In this paper their work is extended to the cases when the region of interest is an echelon, parallelogram, pentagon or hexagon, because of the restirctions imposed on some or all of the mixture components. The principles used in the choice of appropriate designs are those originally introduced by Box and Draper(1959). It is assumed that a response surface equation of first order is fitted, but there is a possibility of bias error due to presence of second order terms in the true model. Minimum bias designs for several cases of restricted regions of interest are illustrated.

• 한국광학회:학술대회논문집
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• 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.235-241
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• 1989

Static according tests were carried out on a series of amorphous TbFe thin films of various composition under a constant laser irradiation condition. Examination of recorded domain configurations by using polarizing microscope led to the categorization of domain characteristics into 3 distinctly different types; i.c., type A: circular domains with smooth boundaries, the size not sensitive to variation of bias field, type B: domains of irregular shape at low bias, the size increasing and the boundaries getting smoother and more circular with increasing bias field and type C: not recordable. Critical factor which distinguishes among each types was fond to be the relative magnitude of H and H of the film near T, regardless of constituent atomic species. Micromagnetical process of thermomagnetic recording cycle was analyzed scheniatically for each type.

• 한국해안·해양공학회논문집
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• 제24권5호
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• pp.333-342
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• 2012

파랑 모델에서 시공간적인 해상도의 변경은 결과에 많은 영향을 끼친다. 본 연구에서는 모델 입력장의 해상도 변경, 파랑 모델의 해상도 변경 그리고 물리적 옵션에 따른 모델의 민감도를 분석하였다. 모델의 분석을 위해서 전지구 부이관측자료와 위성자료를 이용하였다. 고해상도의 입력장을 사용할 경우 유의파고를 과대 산정하는 경향을 보였고, RSME는 약간 감소하였다. 고해상도의 파랑 모델을 수행할 경우 평균편향 및 RMSE가 약간 증가하였다. 또한, 유효 해상풍 계수를 기존의 값인 1.4보다 작게 설정할 경우 편향과 RMSE가 모두 감소하였다.

• 한국강구조학회 논문집
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• 제19권2호
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• pp.139-146
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• 2007

국내 LRFD 도로교설계규정의 휨에 대한 재료 저항계수 정립 시 기초 통계자료로 활용하기 위하여 국산 강재를 적용한 강합성 플레이트 거더 단면의 정모멘트 및 부모멘트 하 휨저항강도를 통계적으로 분석하였다. 최근 국내에서 생산된 16,000여 표본의 구조용 강재와 철근에 대한 항복강도와 인장강도 등의 기계적 특성을 통계적으로 분석하여, 공칭강도에 대한 편심계수(bias factor)와 변동계수(coefficient of variation)를 구하였다. 이들 국산 강재와 철근을 적용하여 정 부모멘트를 받는 도로교 강합성 플레이트 거더교 대표단면에 대한 재료 비선형 소성해석을 수행하였으며, 해석결과로부터 모멘트-곡률 곡선을 구하고 단면의 휨저항강도를 산정하였다. 공칭휨강도와 극한휨저항강도를 비교하고 대표적 강합성 단면에 대한 편심계수와 변동계수 통계치를 제시하였다.

• 한국전자통신학회논문지
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• 제16권1호
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• pp.125-134
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• 2021

영화 산업의 빠른 발전으로 영화의 제작 수가 급격하게 증가하고 있으며, 영화 추천 시스템은 관객들의 과거 행동이나 영화 후기에 기반하여 관객들의 선호도를 예측하여 영화의 선택에 도움을 주고 있다. 본 논문은 평점의 평균과 편향의 보정을 이용하여 잠재요인 모델에 기반한 영화 추천 시스템을 제안한다. 특이값 분해 방법이 평점 매트릭스 분해에 사용되고, 통계 경사 하강법이 최소자승 손실 함수의 파라미터 최적합에 사용된다. 그리고 평균 제곱근 오차를 사용하여 제안한 시스템 성능을 평가한다. Surprise 패키지를 이용하여 제안한 시스템을 구현 하였으며, 모의실험 결과는 평균 제곱근 오차가 0.671이며, 다른 논문에서 방법에 비하여 좋은 성능을 가진다는 것을 확인하였다.

• 한국군사과학기술학회지
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• 제17권4호
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• pp.531-536
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• 2014

There are trapping and stripping methods as the technique to remove the dither motion from RLG(Ring Laser Gyro) output. V/F converter output of angular sensor to measure the dither motion is used in stripping method. But bias and scale factor error is always included in V/F converter output and is a critical limiting factor for the wide application of stripping method to RLG. Therefore there have been many researches to solve this problem. The method to accurately estimate the bias and scale factor error of V/F converter using measurements of the angular sensor acquired at data sampling rate of INS is presented in this paper. To this end, stripping technique based on model of dither motion is newly applied.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2032-2034
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• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface slew discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with the do bias voltage of -10V showed lower discharge voltage and lower erosion rate by ion bombardment than those samples prepared by conventional magnetron sputtering or E-beam evaporation. The main factor that improves the discharge characteristics by bias voltage is considered to be due to the morphology changes or crystal structure of the MgO thin film by ion bombardment during deposition process.

• 한국의류학회지
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• 제27권5호
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• pp.496-504
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• 2003

The purpose of this study was (1) to identify the experimental bias which could appear person perception as results of presentation methods (2) to find out the most desirable method in presentation of stimulus. The research was a quasi experiment and the subjects were 773 male and female undergraduate students. The experimental instruments consisted of a set of stimulus and semantic differential scales of 7- point hi-polar adjectives. The collected data were analyzed by Factor Analysis, ANOVA(analysis of variance), Scheffe＇s multiple range test. The independent variables were presentation orders and presentation time of stimulus. The results were as follows: First, five factors which were potency, sociality, appearance, evaluation, activity impression dimensions emerged to account for the methods of development of stimulus. Second, the presentation order of stimulus in the combination of four stimuli sets had significant effects on the 3 impressional factors(sociality, appearance, evaluation). The presentation order of stimuli in the combination of eight stimuli set had significant effects on the 3 impressional factors(potency, sociality, appearance) and the presentation order of stimuli in the combination of eight stimuli set showed a significant effect on memorization of stimulus and the results support the recency effect. Third, the presentation time of stimuli had significant effects on the 2 impressional factors(potency, activity). 30 seconds presentation as well as free duration time resulted less experimental bias than 3 seconds presentation.

• 대기
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• 제24권4호
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• pp.491-502
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• 2014

As a part of the KIAPS (Korea Institute of Atmospheric Prediction Systems) Package for Observation Processing (KPOP), we have developed the modules for Advanced Microwave Sounding Unit-A (AMSU-A) pre-processing and its bias correction. The KPOP system calculates the airmass bias correction coefficients via the method of multiple linear regression in which the scan-corrected innovation and the thicknesses of 850~300, 200~50, 50~5, and 10~1 hPa are respectively used for dependent and independent variables. Among the four airmass predictors, the multicollinearity has been shown by the Variance Inflation Factor (VIF) that quantifies the severity of multicollinearity in a least square regression. To resolve the multicollinearity, we adopted simple linear regression and Principal Component Regression (PCR) to calculate the airmass bias correction coefficients and compared the results with those from the multiple linear regression. The analysis shows that the order of performances is multiple linear, principal component, and simple linear regressions. For bias correction for the AMSU-A channel 4 which is the most sensitive to the lower troposphere, the multiple linear regression with all four airmass predictors is superior to the simple linear regression with one airmass predictor of 850~300 hPa. The results of PCR with 95% accumulated variances accounted for eigenvalues showed the similar results of the multiple linear regression.