• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.2
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• pp.87-96
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• 1999

To analyze the dynamic behavior of structure, direct integration and mode superposition may be utilized in time domain analysis. As finite number of frequencies can give relatively exact solutions, mode superposition is preferable in analyzing structural behavior. In non-linear analysis, however, mode superposition is seldom used since time-varying element stiffness changes stiffness matrix, and the change of stiffness matrix leads to the change of essential constants - natural frequencies and mode shapes. In spite of these difficulties, there are some attempts to adopt mode superposition because of low cost compared to direct integration, but the result is not satisfactory. In this paper, a method using mode superposition in non-linear analysis is presented by separating local element stiffness from global stiffness matrix with the difference between linear and non-linear restoring forces to the external force vectors included. Moreover, the hysteresis model changing with the relative deformation in each floor makes it possible to analyze non-linear behavior of structure. The proposed algorithm is applied to shear beam model and the maximum displacement is compared with the result using direct integration method.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.5
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• pp.335-344
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• 2011

A curvilinear non-hydrostatic free surface model is developed to investigate nonlinear wave interactions in a circular channel. The proposed model solves the unsteady Navier-Stokes equations in a three-dimensional domain with a pressure correction method, which is one of fractional step methods. A hybrid staggered-grid layout in the vertical direction is implemented, which renders relatively simple resulting pressure equation as well as free surface closure. Numerical accuracy with respect to wave nonlinearity is tested against the fifth-order Stokes solution in a two-dimensional numerical wave tank. Numerical applications center on the evolution of nonlinear waves including diffraction and reflection affected by the curvature of side wall in a circular channel comparing with linear waves. Except for a highly nonlinear bichrmatic wave, the model's results are in good agreement with superimposed analytical solution that neglects nonlinear effects. Through the numerical simulation of the highly nonlinear bichramatic wave, the model shows its capability to investigate the evolution of nonlinear wave groups in a circular channel.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.382-385
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• 2007

본 논문에서는 다중 표적의 중첩이라는 상황에 대한 새로운 해결 방식을 소개한다. 비선형 표적의 위치와 속도에 대한 추적을 중심으로 표적과 비표적의 중첩이 일어나는 순간 이후 분리되었을 때 추적중인 표적을 지속적으로 유지할 수 있는 방법에 대해 이야기 하고자 한다. 이 논문에서 제안된 알고리즘은 예측 명중위치 개념과 최대 잡음수준을 이용한 칼만필터 기반의 적응 상호작용 다중모델 기법으로 측정된 위치값과 예측된 명중위치 사이의 차이를 고려한 변형된 칼만필터 개념을 이용한다. 이 논문에서는 비선형 표적의 가속도를 시변 변수인 표적의 추가적인 잡음으로 두고 각각의 가속도 간격의 정도에 따라 얻어지는 모든 잡음에 대한 변수에 의해 각각의 하부 모델들을 특성화시켰다. 제안된 알고리즘은 표적의 운동특성에 따라 적응적으로 기법을 선택할 수 있는 선택적 방식을 구현하고자 한다. 표적의 기동중에 나타나는 가속도를 효과적으로 다루기 위하여 잡음의 크기가 급격히 증가하는 경우 그 증가분을 가속도로 인식하여 기동표적 관계식에 이용한다. 그리고 제안된 알고리즘의 수행 가능성을 보여주기 위하여 몇 가지 예를 제시하였다.

• Journal of Korea Game Society
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• v.20 no.4
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• pp.47-56
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• 2020

The overall aim of this research was to explore Open-world game through the notion of Paidia and Ludus that proposed by Frasca. As a structured simulation system, the Open World overlap Non-linear events and Linear quests via geographic world. Building own sequence of explore the world with Paidia process, Player collides with the pre-scripted quest. In result of that Meta-Simulator emerge as alternative tool for modeling Meta-Simulation, which presents an alternative, extended use of gameplay.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.13-22
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• 1990

A general analysis method is proposed for analysis of the superposed structures with geometric and material nonlinearities. It is presumed that no friction occurs between structures. It utilizes a shell element for the geometric and material nonlinearities and imposes various deformation constraints for the contact and interaction between structures. To show the reliability and effectiveness of this method, superposed cantilevers for which exact solutions can be obtained and holddown spring assemblies which are now used in PWR reactors are chosen as analysis models. The results of analyses were compared with exact solution in the case of cantilevers and with test results in the case of holddown spring assemblies. The analysis results obtained by this method showed good agreement with the reference values.

• Korean Journal of Optics and Photonics
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• v.10 no.6
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• pp.473-481
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• 1999

We propose a new scheme of hologram multiplexing that can improve the crosstalk noise in the conventional phase-code multiplexing. Our method is based on the idea that the separate holograms to be stored in a certain region of the photorefractve material should have relative phase other than $180^{\circ}$. To demonstrate the new idea we fabricate a phase spatial light modulator using piezo-electric material. The experimental result shows that the crosstalk noise in the restored holograms is reduced much in our method. We also computer simulate the hologram multiplexing and compare the result with the experimental data.l data.

• Proceedings of the Korea Water Resources Association Conference
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• 1988.07a
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• pp.148-157
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• 1988

A generalized hydrograph equation was derived by using the well known concepts of superimposition and nonlinear multiple recessions. Application of the equation showed that characteristics of delay and attenuation of the runoff process were effectively accounted for.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.265-270
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• 2004

불균형중첩오차구조를 갖는 단순선형회귀모형에서 나타나는 두 분산의 합에 대한 신뢰구간을 구하기 위하여 Ting et al.(1990) 방법과 Graybill and Wang(1980) 방법과 Tsui and Weerahandi(1989)가 제안한 일반화 축량(generalized pivotal quantity)방법을 이용한 두 가지 방법 등 모두 네 가지 신뢰구간을 제안한다. 신뢰구간의 적절성을 판단하기 위하여 여러 가지 불균형 설계에 대하여 SAS/IML로 시뮬레이션을 실행하고 신뢰계수와 신뢰구간의 평균 길이를 비교한다. 불균형중첩오차구조를 갖는 단순선형회귀모형의 두 분산의 합에 대한 네 가지 신뢰구간들이 주샘플링 단위의 변화에 따라 어느 방법이 적절한 신뢰구간을 구축하는지 추천하고, 실제 예제를 적용하여 시뮬레이션의 결과와 일관성이 있는지를 확인한다.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.501-508
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• 2003

In this paper A new theory of linear loop transformation called Elimination of Data Dependency(BDD) is presented. The current framework of linear loop transformation cannot identify a significant fraction of parallelism. For this reason, a method to extract the maximum loop parallelism in perfect nested loops is presented. This technique is applicable to general loop nests where the dependence include both distance and directions.

• The Journal of Information Technology
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• v.5 no.1
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• pp.99-111
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• 2002

Due to non-linear characteristics of color spaces, color corrections using linear conversions for real image near color reappearance causes color distortions. In order to overcome this problem, the Bezier Curve, constructed with a set of arbitrary plane in the linear theory, has been used. However, the Bezier Curve increases in proportion to the number of data points, resulting in higher computational complexities. This paper attempts to use a Triplicated Piecewise Bezier Cubic-Curve (TPBC-Curve) of which the degree is cubic on the whole interval while keeping the characteristics of Bezier Curves. By Comparing the TPBC-Curve with Bezier Curve of 20 degree, the paper not only reduces the distortion during color correction but also lessens the relative increase of workload that is caused by the color correction in a small zone.