• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.197-205
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• 2007

We have proposed a novel line detection method based on the estimated probability density function of gradient directions of edges. By estimating peaks of the density function, we determine groups of edges that have the same gradient direction. For edges in the same groups, we detect lines that correspond to peaks of the connectivity weighted distribution of the distances from the origin. In the experiments using the Data Matrix barcode images and LCD images, the proposed method showed better performance than conventional Methods in terms of the processing speed and accuracy.

• Communications of the Korean Mathematical Society
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• v.35 no.1
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• pp.261-268
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• 2020

In this paper, we study gradient Yamabe solitons in the warped product manifolds and classify the warped product manifolds with gradient Yamabe solitons. Moreover we investigate the admitness of gradient Yamabe solitons and geometric structures for some model spaces.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1595-1597
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• 1987

Two gradient methods, steepest descent method and conjugate gradient descent method, are compar ed through application to vector linear predictors. It is found that the convergence rate of the conju-gate gradient descent method is much faster than that of the steepest descent method.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.339-340
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• 2007

Gradient system에 spiral waveform 입력을 가하면 Hardware limitation에 의하여 만들어지는 gradient fields에 Transient time delay가 발생한다. 이를 보상하기 위하여, Gradient system을 R-L-C 회로로 모델링하여 재구성에 필요한 k-space trajectory를 보정하여 개선된 image를 획득하였다.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.589-600
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• 2016

In this paper, we propose a new incremental gradient method for solving a regularized minimization problem whose objective is the sum of m smooth functions and a (possibly nonsmooth) convex function. This method uses an adaptive stepsize. Recently proposed incremental gradient methods for a regularized minimization problem need O(mn) storage, where n is the number of variables. This is the drawback of them. But, the proposed new incremental gradient method requires only O(n) storage.

• Kyungpook Mathematical Journal
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• v.63 no.4
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• pp.639-645
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• 2023

An almost Yamabe soliton is a generalization of the Yamabe soliton. In this article, we deduce some results regarding almost gradient Yamabe solitons. More specifically, we show that a compact almost gradient Yamabe soliton having non-negative Ricci curvature is trivial. Again, we prove that an almost gradient Yamabe soliton with a non-negative potential function and scalar curvature bound admitting an integral condition is trivial. Moreover, we give a characterization of a compact almost gradient Yamabe solitons.

• Kyungpook Mathematical Journal
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• v.57 no.2
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• pp.309-318
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• 2017

The object of the present paper is to study almost Ricci solitons and gradient almost Ricci solitons in 3-dimensional f-Kenmotsu manifolds.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1204-1207
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• 2002

The fixed points of two known gradient flows defined on adjoint orbits of orthogonal groups are analyzed through the critical point analysis of the potential functions. The results show that some known properties of these gradient flows are shared with the gradient flows of the same potential functions with respect to other metrics.

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.91-104
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• 2004

A modification of the gradient method of convex programming is introduced. Also, we describe symbolic implementation of the gradient method and its modification by means of the programming language MATHEMATICA. A few numerical examples are reported.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.280-281
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• 2009

Improving the visual contrast in OLED displays is another important issue to address with a significant technological implication. The use of a gradient refractive index anode shows promise for contrast improvements in OLEDs. This talk will discuss the progress in developing gradient refractive index TCO anode for application in high contrast OLEDs.