• 한국학교수학회논문집
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• 제9권2호
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• pp.121-139
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• 2006

본 논문은 현행 중등수학과 교육과정에서 제시하고 있는 이차함수 관련 내용이 학생 들이 이미 배워서 알고 있는 다항식의 관점이 아니라 새로운 개념인 평행이동과 완전 제곱에 의한 꼭지점 형식의 변형으로 지도함으로써 지도내용 사이의 연계성 상실과 학생들의 개념적 이해를 저해하고 있다는 문제점을 인식했다. 이를 해소하기 위하여 본 연구는 다항식 접근을 통한 이차함수의 성질 탐구와 지도방안을 살펴보며 이 접근의 이점을 몇 가지 구체적인 예를 사용하여 논의하고자 한다.

• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.43-52
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• 1999

The local influence method is adapted to quadratic discriminant analysis for the identification of influential observations affecting the estimation of probability density function probabilities and log odds. The method allows a simultaneous perturbation on all observations so that it can identify multiple influential observations. The proposed method is applied to a real data set and satisfactory result is obtained.

• Journal of the Korean Data and Information Science Society
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• 제22권1호
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• pp.107-113
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• 2011

We present methods for studying the log-density ratio, which allow us to select which predictors are needed, and how they should be included in the logistic regression model. Under multivariate normal distributional assumptions, we investigate the form of the log-density ratio as a function of many predictors. The linear, quadratic and crossproduct terms are required in general. If two covariance matrices are equal, then the crossproduct and quadratic terms are not needed. If the variables are uncorrelated, we do not need the crossproduct terms, but we still need the linear and quadratic terms.

• 대한수학회보
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• 제48권4호
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• pp.713-724
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• 2011

We study the dynamics of transcendental entire functions with Siegel disks whose singular values are just two points. One of the two singular values is not only a superattracting fixed point with multiplicity more than two but also an asymptotic value. Another one is a critical value with free dynamics under iterations. We prove that if the multiplicity of the superattracting fixed point is large enough, then the restriction of the transcendental entire function near the Siegel point is a quadratic-like map. Therefore the Siegel disk and its boundary correspond to those of some quadratic polynomial at the level of quasiconformality. As its applications, the logarithmic lift of the above transcendental entire function has a wandering domain whose shape looks like a Siegel disk of a quadratic polynomial.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2516-2518
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• 2004

This paper proposes a stability condition in discrete-time affine Takagi-Sugeno (T-S) fuzzy systems with parametric uncertainties and then, introduces the design method of a fuzzy-model-based controller which guarantees the stability. The analysis is based on Lyapunov functions that are continuous and piecewise quadratic. The search for a piecewise quadratic Lyapunov function can be represented in terms of linear matrix inequalities (LMIs).

• 수산해양기술연구
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• 제49권2호
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• pp.153-160
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• 2013

Control allocation is an important part of a system. It implements the function that map the desired command forces from the controller into the commands of the different actuators. In this paper, the authors present an approach for solving constrained control allocation problem in vessel system by using multi-parametric quadratic programming (mp-QP) algorithm. The goal of mp-QP algorithm applied in this study is to compute a solution to minimize a quadratic performance index subject to linear equality and inequality constraints. The solution can be pre-computed off-line in the explicit form of a piecewise linear (PWL) function of the generalized forces and constrains. The efficiency of mp-QP approach is evaluated through a dynamic positioning simulation for a vessel by using four tugboats with constraints about limited pushing forces and found to work well.

• 대한전기학회논문지
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• 제43권7호
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• pp.1186-1192
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• 1994

This paper presents an algorithm to design a robust digital model following servo control system in which optimal linear quadratic regulator problem is used to design the control system that make the step/ramp response of the plant kept close to a specified ideal step/ramp response of the model. The quadratic criterion function for a continuous system is used to design the robust digital servo control system. The feasibility of the design technique is shown by the simulation and the proposed method is applied to the speed control of DC servo motor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.844-846
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• 1998

In this study, an adaptive evolutionary computation(AEC), which uses adaptively a genetic algorithm having global searching capability and an evolution strategy having local searching capability with different methodologies, is suggested. This paper develops AEC for solving ELD problem with piecewise quadratic cost function. Numerical results show that the proposed AEC can provide accurate dispatch solutions within reasonable time for the ELD problem with piecewise quadratic cost function.

• 대한전기학회논문지:전력기술부문A
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• 제48권1호
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• pp.31-35
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• 1999

In this paper, we consider the robust pole assignment and the upper bound of quadratic cost function for the linear systems with time-varying uncertainy. The considered uncertainties are both the norm bounded unstructured case and the structured case that has the matrix polytope type uncertain structure. We derve conditions that guarantee the robust pole assignment inside a disk in the L.H.P. and the robust stability. Also, we derive the upper bound of quadratic cost for thil pole assigned systems. Finally, we show the usefulness of our results by an example.

• 응용통계연구
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• 제24권1호
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• pp.61-69
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• 2011

다양한 GARCH류 모형들의 변동성 함수를 살펴보면 흥미롭게도 거의 대부분 모형에서 수익률의 일차항( rst or der term)이나 수익률과 변동성의 교차항(interaction term)이 나타나지 않는다. 일차항과 교차항은 변동성의 비대칭성을 설명하는 역할을 할 수 있으며 $h_t$의 회귀분석식의 형태로 볼 때 변동성 함수의 일반적인 이차형식(quadratic form)을 구성한다고 할 수 있다. 본 논문에서는 변동성과 수익률들 사이의 교차항 및 일차항을 포함한 이차형식(quadratic form) 변동성 모형들을 소개하고, 국내 금융시계열 자료에 적용한 후 비교 분석하고자 한다.