• Journal of Magnetics
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• 제20권4호
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• pp.347-352
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• 2015

The magnetoelectric (ME) characteristics for Terfenol-D/PZT laminate composite dependence on bias magnetic field is investigated. At low frequency, ME response is determined by the piezomagnetic coefficient $d_{33,m}$ and the elastic compliance $s_{33}^H$ of magnetostrictive material, $d_{33,m}$ and $s_{33}^H$ for Terfenol-D are inherently nonlinear and dependent on $H_{dc}$, leading to the influence of $H_{dc}$ on low-frequency ME voltage coefficient. At resonance, the mechanical quality factor $Q_m$ dependences on $H_{dc}$ results in the differences between the low-frequency and resonant ME voltage coefficient with $H_{dc}$. In terms of ${\Delta}E$ effect, the resonant frequency shift is derived with respect to the bias magnetic field. Considering the nonlinear effect of magnetostrictive material and $Q_m$ dependence on $H_{dc}$c, it predicts the low-frequency and resonant ME voltage coefficients as a function of the dc bias magnetic field. A good agreement between the theoretical results and experimental data is obtained and it is found that ME characteristics dependence on $H_{dc}$ are mainly influenced by the nonlinear effect of magnetostrictive material.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1222-1227
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• 1990

The problem of identification of continuous systems is considered when both the discrete input and output measurements are contaminated by white noises. Using a predesigned digital low-pass filter, a discrete-time estimation model is constructed easily without direct approximations of system signal derivatives from sampled data. If the pass-band of the filter is designed so that it includes the main frequencies of both the system input and output signals in some range, the noise effects are sufficiently reduced, accurate estimates can be obtained by least squares(LS) algorithm in the presence of low measurement noises. Two classes of filters(infinite impulse response(IIR) filter and finite impulse response(FIR) filter) are employed. The former requires less computational burden and memory than the latter while the latter is suitable for the bias compensated least squares(BCLS) method, which compensates the bias of the LS estimate by the estimates of the input-output noise variances and thus yields unbiased estimates in the presence of high noises.

• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.305-310
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• 2002

The measured rate of the tracking sensor becomes biased under some operational situation. For a highly maneuverable aircraft in 3D space, the target dynamics changes from time to time, and the Kalman filter using position measurement only can not be used effectively to reject the rate measurement bias error. To cope with this problem, we present a new algorithm which incorporate FIR-type filter and FIR-type fixed-lag smoother, and demonstrate that it has the optimal performance in terms of both estimation accuracy and response time through an application example to the anti-aircraft gun fire control system(AAGFCS).

• Communications for Statistical Applications and Methods
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• 제13권2호
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• pp.319-326
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• 2006

Randomized response technique is a survey technique for eliminating evasive answer bias. This technique is popular in social survey for sensitive issues. In this paper we present a simple and obvious procedure for estimating the population proportion of a sensitive group. Here, we shows the weak point in the method of Kim and Warde (2005). Also, it is found that the proposed procedure is more efficient than the ones of Warner (1965) and Kim and Warde (2005). Lastly we discuss the conditions that the suggested method will be more efficienct.

• Journal of the Korean Statistical Society
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• 제20권2호
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• pp.147-155
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• 1991

This paper treats a robust design criterion which minimizes the effects of outliers and model inadequacy, and investigates robust designs for some response surface designs. In order to develop a robust design criterion and robust design, the integrated mean squared error of *(equation omitted) over a region is utilized, where *(equation omitted). is the estimated response by the minimum bias estimation proposed by carson, Manson and Hader (1969) . According to the number of aberrant observations and their positions, the proposed criterion and designs are studied. Also further development of the proposed criterion is treated when outliers can occur in any position of a design.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7203-7206
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• 2013

Recent studies suggested that the ovarian cancers with negative excision repair cross-complementation group 1 enzyme (ERCC1) expression have a better response to platinum-based chemotherapy than those with positive ERCC1 expression. The objective of this study was to evaluate whether ERCC1 expression is associated with response to platinum-based chemotherapy in ovarian cancers. MEDLINE, PubMed, Web of Science and CNKI databases were used for searching studies relating to ERCC1 protein expression and response to platinum-based chemotherapy in ovarian cancers. Statistical analysis was based on the method for a fixed effects meta-analysis. Pooled odds ratios (ORs) with 95% confidence intervals for ERCC1 protein expression and response to platinum-based chemotherapy were generated. Publication bias was investigated with Begg's test. Five studies involving 306 patients with ovarian cancer were included. Compared to patients with positive ERCC1 expression, those with negative ERCC1 expression had a better response to platinum-based chemotherapy. The pooled OR was 5.264 (95% CI: 2.928-9.464, P < 0.001) and publication bias was not found (P = 0.904). The result was similar in both in Asians and Caucasians (P < 0.001 and P = 0.028, respectively). ERCC1 protein expression status is significantly associated with response to platinum-based chemotherapy in ovarian cancers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.186-186
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• 2009

Most liquid crystal display modes, including the twisted nematic (TN) $mode^1$, the in-plane switching (IPS) $mode^2$, the fringe field switching (FFS) $mode^3$, and the vertically aligned (VA) $mode^4$ are based on either a horizontal or a vertical alignment. However, for some applications, such as no-bias-bend (NBB) pi cell or bistable bend-splay display, an intermediate pretilt angle is essential$^5$. NBB pi cells have been a focus of interest because of their fast response time; however, the reliable control of the intermediate pretilt angle of liquid crystals that is required for the fabrication of NBB pi cells is challenging. The controllable pre-tilt angle of liquid crystals was investigated using a blend of horizontal and vertical polyimide prepared by a rubbing method. Various pretilt angles in the range from 0^{\circ}$ to 90^{\circ}$ were achieved as a function of the vertical polyimide content. We observed uniform liquid crystal alignment on the rubbing-treated blended polyimide layer. A NBB pi cell with an intermediate pretilt angle of 47.8^{\circ}$ was manufactured. This cell had no initial bias voltage and a low threshold voltage, which indicates that it has low power consumption. In addition, the response time of the NBB pi cell was rapid.

• 응용통계연구
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• 제15권2호
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• pp.395-403
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• 2002

반응표면방법론에서의 세번째 단계에서는 일차모형이 가정되고, 반응표면의 곡선효과는 중앙점과 2수준 부분실시법에서의 실험을 통해서 검토된다. 참모형이 2차 모형인 경우를 가정하자. 최적실험계획을 선택하기 위해서 Box와 Draper(1959)는 관심영역에서 예측치 y(x)의 평균제곱오차를 적분한 값인 가중평균제곱오차(AMSE)를 최소화 시키는 최적실험계획 기준을 제안하였다. AMSE는 예측치의 가중분산과 가중제곱편의 량의 합으로 분할될 수 있다. AMSE는 실험계획 적률과 참모형의 회귀계수들의 값에 종속되어서 가중평균제곱오차를 최 소화하는 실험 계획을 찾기는 불가능하다. 실용적인 대안으로 Box와 Draper(1959)는 가중제곱편의 량을 최소화하는 실험계획을 제안했고, 이 실험계획의 상자점들이 중앙점을 향해서 축소됨을 보였다. 이 논문에서는 표준화된 회귀계수들의 값에 대해서 실험계획의 최소효율을 최대화하는 강건한 실험계획을 제안한다.

• 한국자기학회지
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• 제4권3호
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• pp.239-243
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• 1994

NiFe와 TbCo의 게면에서의 자기 교환 결합을 이용하여 자기 저항 소자에 수평 및 수직 바이어스 자장을 제공할수 있도록 $NiFe/TbCo/Si_3N_4$ 박막을 제조하였다. Tb의 면적비가 36 %이고, 기판 바이어스를 인가하지 않았을때 100~180 Oe의 교환 자장을 얻을 수 있었다. NiFe, TbCo, 그리고 보호막으로 사용되는 $Si_3N_4$ 각층의 두께는 각각 $470\;{\AA},\;2400\;{\AA},\;600\;{\AA}$ 이었다. NiFe를 1000 W의 전력과 2.5 mTorr의 아르곤 압력에 제작한 시편에서 1.45 %의 자기 저항 변화율을 얻을 수 있었다. 미세 소자로 제작된 NiFe의 자기 저항 변화율은 1.31 %로 감소 하였으며, 감자화 자장의 영향으로 박막이 완전히 포화되지 못한 곡선을 보였다. 150 Oe의 교환 자 장을 갖는 박막을 자화 용이 방향과 $36^{\circ}$의 각도로 소자를 제작한 결과 약 85 Oe 정도의 자기 저항 응답 곡선의 천이를 보였으며, 소자의 동작점이 응답의 선형 구간으로 이동하였다. 또한 Barkhausen 잡음이 교환 자장에 의한 수평 바이어스에 의하여 제거되었다.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.3185-3199
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• 2018

본 연구에서는 운전장면 개별요소들에 대한 중년 및 고령운전자의 작업기억의 특성을 반응민감도, 반응편파 및 반응시간을 통해 비교하였다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 고령운전자 집단은 중년운전자 집단에 비해 민감도가 낮았고 특히 중년운전자 집단의 경우는 중심자극과 주변자극에 대한 민감도에서의 차이가 유의하지 않았던 반면, 고령운전자 집단의 경우는 중심자극에 비해 주변자극에 대한 민감도가 현저하게 더 낮았다. 둘째, 중년운전자 집단은 전반적으로 보수적으로 반응한 반면 고령운전자 집단은 대체적으로 관대한 방향으로 반응하는 경향이 상대적으로 더 컸다. 셋째, 중년운전자들에 비해 고령운전자들의 반응시간이 더 느렸고, 중심자극보다는 주변자극에 대한 반응시간이 더 느렸으며, 반응의 유형에 따라서는 적중의 반응시간이 가장 빨랐던 반면 헛경보의 반응시간이 가장 느렸다. 특히, 탈루과 정기각 반응에 대해서는 두 집단 사이의 반응시간 차이가 더 증가하였다. 이러한 결과는 중년운전자들에 비해 고령운전자들은 운전장면 개별요소에 대한 작업기억에서의 파지가 상대적으로 더 불완전하고, 이에 따라 작업기억에 기초한 신속한 판단에서 어려움이 증가할 수 있음을 시사한다.