• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.134-139
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• 2011

Since large and small scale photovoltaic(PV) systems have been commercialized in many countries, it is necessary to assess the effects of PV systems on the electric power system. For this, the development of accurate simulation model of PV arrays is very important. PSCAD/EMTDC, a widely used simulation tool for analyzing the transient behavior of electrical apparatus and networks, does not have a standard model of a PV array. Therefore in order to simulate the PV array, users have to develop their own simulation model. However, the block-diagram-based model is very complicated, and it is hard to modify the model parameters. In this study, we develop the user-defined model of a PV array by using the Design Editor, which is provided by PSCAD program. The mathematical model of a PV array and the method to determine the parameters of nonlinear I-V equation are implemented in a Fortran code. The graphical user interface provides the users with easy and simple way to modify the PV array parameters and simulation conditions. In order to help the users, this model also provides the parameters of 10 commercial PV arrays.

• Journal of the military operations research society of Korea
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• v.28 no.1
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• pp.47-66
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• 2002

Instead of using signal-to-noise ratio, we attempt to optimize both the mean and variance responses using dual response optimization technique. The alternative experimental strategy analyzes a robust parameter design problem to obtain the best settings that give a target condition on the mean while minimizing its variance. The mean and variance are treated as the two responses of interest to be optimized. Unlike to the crossed array and combined array approaches, our experimental setup requires replicated runs for each control factor's treatment under noise sampling. When the postulated response models are true, they enable the coefficients to be estimated and the desired performance measure to be analyzed more efficiently. The procedure and illustrative example are given for the dual response optimization techniques of nonlinear goal programming.

• Journal of information and communication convergence engineering
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• v.14 no.1
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• pp.51-56
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• 2016

In this paper, we present a three-dimensional (3-D) automatic target recognition system based on optical integral imaging reconstruction. In integral imaging, elemental images of the reference and target 3-D objects are obtained through a lenslet array or a camera array. Then, reconstructed 3-D images at various reconstruction depths can be optically generated on the output plane by back-projecting these elemental images onto a display panel. 3-D automatic target recognition can be implemented using computational integral imaging reconstruction and digital nonlinear correlation filters. However, these methods require non-trivial computation time for reconstruction and recognition. Instead, we implement 3-D automatic target recognition using optical cross-correlation between the reconstructed 3-D reference and target images at the same reconstruction depth. Our method depends on an all-optical structure to realize a real-time 3-D automatic target recognition system. In addition, we use a nonlinear correlation filter to improve recognition performance. To prove our proposed method, we carry out the optical experiments and report recognition results.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.243-244
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• 2008

In this paper proposed the solar tracking system to use a fuzzy based on PC in order to increase an output of the PV array. The solar tracking system operated two DC motors driving by signal of photo sensor. The control of dual axes is not an easy task due to nonlinear dynamics and unavailability of the parameters. The fuzzy control made a nonlinear dynamics to well perform and had a robust and highly efficient characteristic about a parameter variable as well as a nonlinear characteristic. In this paper designed a fuzzy controller for improving output of PV array and evaluated comparison with efficient of conventional PI controller. The data which were obtained by experiment were able to show a validity of the proposed controller.

• Journal of Sensor Science and Technology
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• v.23 no.2
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• pp.99-104
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• 2014

Sensor arrays based on chemical sensors produce multidimensional patterns of data that may be used discriminate between different chemicals. For the human observer, visualization of multidimensional data is difficult, since the eye and brain process visual information in two or three dimensions. To devise a simple means of data inspection from the response of sensor arrays, PCA (Principal Component Analysis) or Sammon's nonlinear mapping technique can be applied. The PCA, which is a well-known statistical method and widely used in data analysis, has disadvantages including data distortion and the axes for plotting the dimensionally reduced data have no physical meaning in terms of how different one cluster is from another. In this paper, we have investigated two techniques and proposed a combination technique of PCA and nonlinear Sammom mapping for visualization of multidimensional patterns to two dimensions using data sets from odor sensing system. We conclude the combination technique has shown more advantages comparing with the PCA and Sammon nonlinear technique individually.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.10
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• pp.894-900
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• 2006

This paper reports the fabrication and characterization of $32{\times}32$ thermal cantilever array for nano-scaled memory device applications. The $32{\times}32$ thermal cantilever array with integrated tip heater has been fabricated with micro-electro-mechanical systems(MEMS) technology on silicon on insulator(SOI) wafer using 9 photo masking steps. All of single-level cantilevers(1,024 bits) have a p-n junction diode in order to eliminate any electrical cross-talk between adjacent cantilevers. Nonlinear electrical characteristic of fabricated thermal cantilever shows its own thermal heating mechanism. In addition, n-channel high-voltage MOSFET device is integrated on a wafer for embedding driver circuitry.

• Korean Journal of Mathematics
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• v.17 no.2
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• pp.197-210
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• 2009

We prove the existence of multiple solutions (${\xi},{\eta}$) for perturbations of the elliptic system with Dirichlet boundary condition $$(0.1)\;\begin{array}{lcr}A{\xi}+g_1({\xi}+ 2{\eta})=s{\phi}_1+h\;in\;{\Omega},\\A{\xi}+g_2({\xi}+ 2{\eta})=s{\phi}_1+h\;in\;{\Omega},\end{array}$$ where $lim_{u{\rightarrow}{\infty}}\frac{gj(u)}{u}={\beta}_j$, $lim_{u{\rightarrow}-{\infty}}\frac{gj(u)}{u}={\alpha}_j$ are finite and the nonlinearity $g_1+2g_2$ crosses eigenvalues of A.

• Korean Journal of Mathematics
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• v.17 no.4
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• pp.495-505
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• 2009

By means of Green function and fixed point theorem related with cone theoretic method we show that there exist multiple nonnegative solutions of a Dirichlet problem $$\array{-[p(t)x^{\prime}(t)]^{\prime}={\lambda}q(t)f(x(t)),\;t{\in}I=[0,\;T]\\x(0)=0=x(T)}$$, and a mixed problem $$\array{-[p(t)x^{\prime}(t)]^{\prime}={\mu}q(t)f(x(t)),\;t{\in}I=[0,\;T]\\x^{\prime}(0)=0=x(T)}$$, where ${\lambda}$ and ${\mu}$ are positive parameters.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.151-154
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• 1998

이 논문에서 비선형 배열 MUSIC 빔형성 기법을 이용하여 예인형 선배열 센서 시스템의 표적 좌우 방위 분리 방법을 기술하였다. 이 기법은 배열 운동모델 Water-Pully 모델과 방향센서의 정보를 이용하는 칼만필터를 설계하여 예인함 기동에 따른 배열형상을 추정하고 표적의 좌우방위를 분리하기 위하여 추정된 배열형상에서 MUSIC 빔형성 기법으로 신호처리를 수행하였다. 또한 예인주기와 예인진폭과 같은 예인함 기동형태의 전형적인 빔형성 기법과 MUSIC 빔형성 기법으로 표적의 좌우 방위 분리 성능을 비교 분석하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.2
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• pp.163-173
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• 2012

This study covers the nonlinear analysis of anchor head for high strength prestressing strand and presents necessary process in improving the performance of anchor head. The surface of wedge for strand is contacted to the surface of the wedge hole on anchor head when it is fitted into the wedge hole, and the contact condition changes according to the level of load applied through the wedge. In order to analyze detailed behavior, nonlinear material model and contact element were used in analysis. It was found from the analysis that the behavior of anchor head is affected by the interaction with the wedge contacted so that the wedge in FE model should have the same figure as the actual object. Circular array of wedge hole presents better stress distribution than layer array even though the small difference in maximum deformation. Increment of thickness of anchor head and distance of wedge hole also improve the performance of anchor head.