• 한국수학교육학회지시리즈E:수학교육논문집
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• 제33권2호
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• pp.105-122
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• 2019

교과서에서는 도형 f(x, y) = 0을 x축 방향으로 a만큼, y축 방향으로 b만큼 평행이동한 도형의 방정식을 구할 때 도형 f(x, y) = 0 위의 임의의 점을 점 (x, y)로, 평행이동 된 도형 f(x-a, y-b) = 0 위의 점은 점 (x', y') 로 표현하고 있다. 도형 f(x, y) = 0 위의 임의의 점을 점 (x, y)로 표현한다면 점 (x, y)와 도형 f(x, y) = 0은 다른 대상인데 같은 문자들이 사용되어지고 있다. 본 연구에서는 이러한 교과서의 표현이 50년 넘게 고수되어, 학생들의 사고가 경직되므로, 개선이 필요하다고 보고 다음과 같이 연구한다. 첫째, 공식을 유도할 때, 도형 위의 임의의 점을 교과서와 달리 표현했을 때의 학생들의 반응은 어떠한가? 둘째, 살펴본 결과를 바탕으로 교과서 표현을 어떻게 수정할 것인가? 셋째, 수정한 표현에 대해 학생들은 어떻게 반응하는가? 그 결과 도형 위의 임의의 점을 교과서와 달리 표현하고 평행이동 된 도형 위의 점을 점 (x, y)로 두었더니, 조사한 학생들은 모두 본 연구에서 개선한 설명이 더 쉽다고 응답하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제27권3호
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• pp.71-79
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• 2023

지진이 발생한 후 구조물의 안전성을 평가하기 위해 모든 교량 및 건축물에 지진가속도 및 변위를 계측하는 유지관리시스템을 구축하기는 효율적이지 않아, 이를 유지관리하기 위해서는 현장조사가 시행되며 조사범위가 넓은 경우 많은 시간이 소요된다. 그로 인해 2차 피해가 발생할 우려가 있으므로 신속한 개별 구조물의 안전성을 추정할 필요가 있다. 구조물의 지진 손상은 구조물에 인가된 지진력 정보와 구조해석모델을 이용하여 위험도평가 해석을 통해 예측할 수 있다. 이를 위해 지진 발생 시 임의위치에서 발생한 지진력을 추정할 필요가 있다. 본 연구에서는 국내 지진계측 기록과 선형추정방법 및 인공신경망 학습 방법을 활용한 임의위치의 지반 응답스펙트럼 및 가속도시간이력을 추정하는 방법들을 제안하고 적용성을 평가하였다. 선형추정방법의 경우 추정에 사용되는 인근 관측소의 위치가 가까울 경우 오차가 적었지만 멀어질 경우 오차가 크게 증가하였다. 인공신경망 학습 방법의 경우 동일한 조건에서 더 낮은 수준의 오차로 추정할 수 있었다.

• Journal of electromagnetic engineering and science
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• 제3권2호
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• pp.126-132
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• 2003

In this paper, a coupled-line type waveguide bandpass filter is newly proposed. The proposed bandpass filter configuration consists of magnetically coupled waveguide cavities. In order to show the background of the proposed waveguide bandpass filter, the general coupled line TEM bandpass filter theory, which means the coupled line filter with arbitrary coupled line length and impedance level, will be briefly introduced. Calculations for the even- and odd-mode wave impedance of a coupled line waveguide structure are achieved based on the normalized impedance concept for a broad-side coupled waveguides by using vector finite element method(VFEM) calculation. Measured result of an implemented coupled-line type waveguide filter is presented.

• Clinical and Experimental Pediatrics
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• 제57권10호
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• pp.425-433
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• 2014

Adrenal and thyroid hormones are essential for the regulation of intrauterine homeostasis, and for the timely differentiation and maturation of fetal organs. These hormones play complex roles during fetal life, and are believed to underlie the cellular communication that coordinates maternal-fetal interactions. They serve to modulate the functional adaptation for extrauterine life during the perinatal period. The pathophysiology of systemic vasopressor-resistant hypotension is associated with low levels of circulating cortisol, a result of immaturity of hypothalamic-pituitary-adrenal axis in preterm infants under stress. Over the past few decades, studies in preterm infants have shown abnormal clinical findings that suggest adrenal or thyroid dysfunction, yet the criteria used to diagnose adrenal insufficiency in preterm infants continue to be arbitrary. In addition, although hypothyroidism is frequently observed in extremely low gestational age infants, the benefits of thyroid hormone replacement therapy remain controversial. Screening methods for congenital hypothyroidism or congenital adrenal hyperplasia in the preterm neonate are inconclusive. Thus, further understanding of fetal and perinatal adrenal and thyroid function will provide an insight into the management of adrenal and thyroid function in the preterm infant.

• International Journal of Reliability and Applications
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• 제6권2호
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• pp.87-99
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• 2005

Coverage-based software reliability growth models (SRGMs) have been developed and successfully applied in practice. Performance of a coverage-based SRG M depends on the coverage function employed by the SRGM. When the coverage function represents the coverage growth behavior well irrespective of type of the testing profile the corresponding coverage-based SRGM is expected to be widely applicable. This paper first conducts a study of selecting the most representative coverage functions among the available coverage functions. Then their performances are empirically evaluated and compared. The result provides a foundation for developing widely applicable coverage-based SRGMs and monitoring the progress of a testing process.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.2045-2050
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• 2004

An optimal combination of arbitrary number correlated estimates is derived. In particular, for two estimates this combination represents the well-known Millman and Bar-Shalom-Campo formulae for uncorrelated and correlated estimation errors, respectively. This new result is applied to the various estimation problems as least-squares estimation, Kalman filtering, and adaptive filtering. The new approximate adaptive filter with a parallel structure is proposed. It is shown that this filter is very effective for multisensor systems containing different types of sensors. Examples demonstrating the accuracy of the proposed filter are given.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1240-1243
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• 2003

In this paper, an encryption method to share a secret binary image is proposed. It divides the image to be encrypted into an arbitrary number of images and encrypts them using XOR process with different binary random images which was prepared by the means of the XOR process, too. Each encrypted slice image can be distributed to the authenticated ones. However, we transfer the encrypted images to the binary phase masks to strengthen the security power, that means phase masks can not be copied with general light-intensity sensitive tools such as CCDs or cameras. For decryption, we used the Mach-Zehnder interferometer in which linearly polarized two light beams in orthogonal direction, respectively. The experimental result proved the efficiency of the proposed method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.573-576
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• 2004

This paper proposes an analytic method that can estimate delay time considering crosstalk noise at an arbitrary node of RC-class interconnects under saturated ramp input using a simple closed-form expression. In the case of single interconnects, algebraic expression presented in existent research can estimate delay time under ramp input using delay time under step input, and we applied it to estimate delay time considering crosstalk noise. As the result, we can provide a intuitive analysis about signal integrity of circuits that include crosstalk noise reducing computational complexity significantly.

• Journal of Information Technology Applications and Management
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• 제14권1호
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• pp.21-36
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• 2007

We face with numerous situation of decision making. In this situation, we would make decision through individual's own information, or others' decision making with ignoring private information, Also we would make decision through compromise of private information and others' information. like this, we call situation to imitate information of previous decision maker, with disregarding private own information,'information cascades' Also, anchoring effects are results of insufficient adjustment from an arbitrary value. In this paper, we examined how information cascades effects and anchoring effects would be generated in the people who use IT technique as instant poll of website. And this paper presents alternatives to decrease information cascades effects and anchoring effects. This exercise provides facts anchoring effects occur when voters can see poll result. And this paper shows that more degree of output difference is deepened, and more anchoring effects occur. Also this paper shows that when website gives positive payoff, more anchoring effects occur.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.507-512
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• 1993

In this paper we discuss the nonlinear motion of a conservative two-link arm using first integrals, which includes one integral constant. In the analysis of the motion, the constant plays important role. First, we give some discussion on the free motion by focusing on the integral constant. As the result, the free motion can be classified into two types-the one is oscillation and the other is rotation. Second, we discuss the forced motion of the arm actuated only at the second joint. We take the first integral in a more general form, and show that the forced motion of the second link can be expressed as a variation of the integral constant. Also, the characteristic of the forced motion actuated by arbitrary constant torques is discussed.