• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.163-172
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• 2004

In the software development project applying object-oriented development methodology, the research on the UCP(Use Case Point) as a method to estimate development effort is being carried on. The existing research proposes the linear model calculating the development effort that multiplies an invariant on AUCP(Adjusted Use Case Point) which applied technical and environmental factors. However, the statistical model that estimates the development effort using AUCP and UUCP(Unadjusted Use Case Point) is not being studied. The irrelevant relationship of the linear regression model, whose development period is increasing tremendously as the software size increases, is confirmed. Moreover, during the UCP calculating process, there can be errors in FP by applying the TCF(Technical Complexity Factor) and EF(Environmental Factor). This paper presents a non-linear regression model, that does not consider the TCF and EF, and that estimate the development effort from UUCP directly by utilizing the exponential function. An exponential function is selected among the linear, logarithm, polynomial, power, and exponential model via statistical evaluations of the models mentioned above.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.147-157
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• 2009

Recently, there has been continued research on UCP from the development effort estimation method to a software development project applying object oriented development methodology. Current research proposes a linear model estimating the developmenteffort by multiplying a constant to AUCP which applies technical and environmental factors. However, the fact that a non-linear regression model is more appropriate as the software size increases, the development period increases exponentially. In addition, in the UCP calculation process the occurrence of FP errors due to the application of TCF and EF, it is unrealistic to estimate the size with AUCP. This paper presents the issue of current research based on UCP without considering problems of the research, for example, TCF and EF and expresses the models (linear, logarithmic, polynomial, power and exponential type) estimating the development effort directly from UUCP. Consequently, the exponential model within non-linear models exhibit more accurate results than the current linear model. Therefore, after calculating the UUCP of the developing software system, using the proposed model to estimate the development effort, it is possible to estimate the direct cost required in development.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.1 no.2
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• pp.49-56
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• 1987

To save energy consumption, it is proposed to operate a discharge lamp with high frequency power. When designing a high frequency operating circuit containing a discharge lamp, the character of a lamp may be needed. And there are various methods to get and models for this. In this study, to present the volt-ampere character of a fluorescent lamp which gives a good saving effect, the nonlinear resistance model is suggested. And the validity of the model is verified by applying the model for the circuits with inductor ballast and capacifor ballast. This model, in contrast with the others, can be easily obtainable. And for comparison, the model using a modified Francis equation is examined. The method used in this study can be basically applied to the other discharge lamps. As a result, 1) Approximated 3rd order polynomial of nonlinear resistance model gives a good simulation result. 2) When operating in high frequency, the model using a modified Francis equation with constant coefficients can't be applied.

• Nuclear Engineering and Technology
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• v.25 no.1
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• pp.110-124
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• 1993

A Nonlinear model-based Hybrid Controller (NHC) is developed which consists of the adaptive proportional-integral-feedforward (PIF) gains and variable structure controller. The controller has the robustness against modeling uncertainty and is applied to the trajectory tracking control of single-input, single-output nonlinear systems. The essence of the scheme is to divide the control into four different terms. Namely, the adaptive P-I-F gains and variable structure controller are used to accomplish the specific control actions by each terms. The robustness of the controller is guaranteed by the feedback of estimated uncertainty and the performance specification given by the adaptation of PIF gains using the second method of Lyapunov. The variable structure controller is incorporated to regulate the initial peak of the tracking error during the parameter adaptation is not settled yet. The newly developed NHC method is applied to the power tracking control of a nuclear reactor and the simulation results show great improvement in tracking performance compared with the conventional model-based control methods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.435-444
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• 2006

This paper investigates the effect of 3-dimensional FE models to evaluation results of jointed concrete pavements which is back-calculated by AREA method. Sensitivity of 3-dimensional FE models developed to simulate the behavior of real jointed concrete pavement are analyzed after compared with 2-dimensional FE models using ILLISLAB. In comparison with 2-dimensional models, influence of concrete contraction under loading plate and base layer on surface deflections is more than that of loading configuration. Deflections at 3-dimensional model between linear and nonlinear temperature distribution under same temperature difference are similar, but noticeable differences are investigated in low elastic modulus of foundations. Dynamic deflections under loading plate are larger than static deflections in high elastic modulus of foundation, but smaller in low elastic modulus. Lower dynamic modulus of subgrade reactions are backcalculated by dynamic deflections than by static deflections. But reverse trend is investigated in the backcalculated elastic modulus of concrete which describes trends of the field backcalculation values calculated from AREA method.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1901-1902
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• 2008

얼굴 인식은 얼굴의 특징적인 패턴을 이용하지만, 이러한 패턴은 표정, 포즈, 조명의 변화에 민감하여 인식에 어려움이 있다. 본 논문은 표정 변화에 강인한 인식 모델을 개발하기 위해 Cohn-Kanade 표정 데이터베이스와 AAM을 이용하여 다양한 데이터를 추출하였고, 추출된 데이터를 다선형 분석을 이용하여 분석하였다. 이를 적용한 인식 실험에서 PCA보다 표정에 좀 더 강인한 인식 성능을 나타내었다.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1163-1165
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• 2010

가솔린 기관의 체적 효율은 흡기 장치의 효율의 척도로 표현된다. 현재 체적효율은 4행정 가솔린 엔진의 흡기장치의 특성과 공연비 제어를 위한 중요한 파라미터로 사용되고 있다. 체적 효율은 이론적으로 실린더로 흡입 가능한 양에 대한 실제로 실린더로 흡인한 공기량의 비율이다. 체적효율은 엔진회전 속도와 흡기다기관 부압에 따라 결정되는 종속변수이다. 체적 효율은 정상상태와 과도상태와 같은 엔진의 모든 운전조건을 시험하는데 한계와 제약이 매우 크다. 이 논문에서는 선형 알고리즘을 사용하여 체적 효율의 파라미터를 규명하여 선형 다항식 모델을 개발한다. 그리고 실험으로 구한 체적효율 데이터와 다항식 모델을 비교하고 객관적인 타당성을 평가 하였다.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.571-574
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• 1997

항법장치의 핵심요소인 가속도센서와 자이로센서는 선형거리추측(Linear position estimation)과 각 변위 추측(orientation estimation)시 출력 데이터에 포함된 오차성분의 적분에 의하여 시간이 증가함에 따라 선형거리 오차와 각 변위 오차가 누적된다. 이에 따라 본 논문에서는 정밀한 항법을 위한 저가의 IMU (Inertial Measurement Unit)를 설계하고, 오차성분의 사전해석을 통하여 정확한 오차모델을 찾는데 그 목적이 있다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.147-150
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• 1998

다양한 응용분야에서 디지털 칼라영상은 프린터를 통ㅎ여 출력되어진다. 이러한 출력 장비들의 하드웨어적 특성은 칼라 영상의 색을 왜곡시켜 부정확한 색 재현을 얻게 된다. 본 논문에서는 색채학적 모델에 기반한 다차 비선형변환을 이용하여 주어진 칼라 프린터의 특성을 알아내고 이를 보정하는 방법을 제시한다. 또한, 샘플의 개수를 변화하면서 비선형 변환식을 계산하여 기기의 특성화 모델링 과정에 필요한 적정수준의 샘플 개수를 제시한다. 실험을 통하여 원본의 색과 재현되어진 색의 색차를 구함으로써 제시되어진 방법의 타당성을 검증한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.69-85
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• 1998

본 연구에서는 부품 및 시스템 고장률 모형에 대한 추계적 과정 접근법을 제시하고 기존의 이론 분포 중심 접근법에서 탈피하여 부품고장률을 시계열 모형으로 설정하고 이에 따른 복합시스템 고장율의 선형결합에 대한 모델을 제시하며 주요 모델에 대한 수치예를 든다. 또한 Burn-In 테스트에 사용되는 욕조(Bathtub) 고장률 모형에 대한 기존의 혼합분포 접근법의 대체 방법으로 비선형 시계열 모형을 제안한다.