• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.201-204
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• 2000

본 논문에서는 기존의 칼라 항상성(color constancy) 알고리즘을 기반으로 한 새로운 영상 복원 방법을 제안한다. 이 방법은 인간의 시각 특성을 선형 모델로 표현한 칼라 항상성 모델을 이용한다. 칼라 항상성 모델에서 가장 중요한 과정은 영상의 광원을 추정하는 것이다. 이론 위하여 영상에서 명도 값이 가장 큰 화소의 값을 이용하며, 이 값을 각 수광체(photoreceptor)의 응답으로 대체한다. 추정된 광원을 이용하여 만들어진 영상을 일정한 비율로 스케일링하여 영상을 복원한다. 실험을 통하여 제안한 항법으로 영상 복원이 잘 됨을 알 수 있었다.

• Bulletin of the Korean Mathematical Society
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• v.56 no.5
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• pp.1327-1340
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• 2019

We establish a monotonicity formula of V-harmonic maps by using the stress-energy tensor. Use the monotonicity formula, we can derive a Liouville type theorem for V-harmonic maps. As applications, we also obtain monotonicity and constancy of Weyl harmonic maps from conformal manifolds to Riemannian manifolds and ${\pm}holomorphic$ maps between almost Hermitian manifolds. Finally, a constant boundary-value problem of V-harmonic maps is considered.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.3
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• pp.1-10
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• 2010

In this paper, we propose a novel way of combining color demosaicing and the auto white balance (AWB) method, which are important parts of image processing. Performance of the AWB is generally affected by demosaicing results because most AWB algorithms are performed posterior to color demosaicing. In order to increase the performance and efficiency of the AWB algorithm, the color constancy problem is considered during the color demosaicing step. Initial estimates of the directional luminance and chrominance values are defined for estimating edge direction and calculating the AWB gain. We propose a modified edge-based AWB method that used a pre-defined achromatic region. The estimation of edge direction is performed region adaptively by using the local statistics of the initial estimates of the luminance and chrominance information. The proposed method shows significant improvements in terms of visual and numerical criteria when compared to conventional methods.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.9_10
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• pp.1384-1395
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• 2007

The purpose of this study was to investigate the factors of hairdo attitude and hairdo involvement, the differences in the hairdo involvement by hairdo attitude. The questionnaires were given to female residents in Seoul and Kyung-gi do during September to October 2006. 406 questionnaires were used for data analysis. The collected data were analyzed using SPSS 12.0 software such as factor analysis, Cronbach's alpha, ANOVA test and Duncan test. The results of this study were as follows: 1. The hairdo attitude factors were found to be 'leader's fashion conformity', 'distinct individuality', 'constancy', and 'consciousness of others' The hairdo involvement factors were found to be 'interests in hairdo', 'fashionableness', 'symbolic representation', 'risk awareness', and 'coordination of hairdo'. 2. As for the hairdo attitude, two groups were identified as the highly-oriented group and the lowly-oriented group. There were significant differences in all hairdo involvement factors depending on two groups. Highly-oriented groups of 'leader's fashion conformity' considered more about interests in hairdo, fashionableness, symbolic representation, and coordination of hairdo, except for risk awareness, signalling that the more people respond to leader's fashion, the higher they are involved with hairdo. Highly-oriented group of 'constancy' showed significant differences in fashionableness and risk awareness. Lower level of fashionableness but higher level of risk awareness than the lowly-oriented group. Highly-oriented group of 'consciousness of others' displayed high performance in all factors, implying that the more people respond to feedback and evaluation of others, the higher they are involved with hairdo.

• Korean Journal of Cognitive Science
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• v.17 no.4
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• pp.287-301
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• 2006

Two experiments were performed to investigate effects of background depth information on the judgment of two-dimensional shapes, using the Posner et al.'s(1969) physical match task. In both experiments, the focus was on whether the background depth information affects the decisions of physical shape sameness of two letters or figures presented successively. In Experiment 1, artificially constructed rues of linear perspective and texture gradient were used, whereas cues contained in a real road situation were used in Experiment 2. The results of both experiments showed that the depth cues affect the perception of two-dimensional shapes. That is, when two stimuli of the same physical shape were likely to be perceived differently due to the given depth cues, response accuracies('yet' in this case) decreased and reaction tines of physical match increased. And when two stimuli of the different physical shape were likely to be perceived the same due to the given depth cues, response accuracies('no' in this case) decreased and reaction times of physical match increased likewise. These results wert discussed in terms of some conceptual methodological problems of the previous studies on the shape constancy and the directions of future research.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.111-120
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• 2015

HDR(High dynamic range) imaging is a technique to represent a dynamic range of real world. Exposure fusion is a method to obtain a pseudo-HDR image and it directly fuses multi-exposure images instead of generating the true-HDR image. However, it results ghost artifacts while fusing the multi-exposure images with moving objects. To solve this drawback, temporal consistency assessment is proposed to remove moving objects. Firstly, multi-level threshold bitmap and brightness bitmap are proposed. In addition, hue-angle constancy map between multi-exposure images is proposed for compensating a bitmap. Then, two bitmaps are combined as a temporal weight map. Spatial domain image quality assessment is used to generate a spatial weight map. Finally, two weight maps are applied at each multi-exposure image and combined to get the pseudo-HDR image. In experiments, the proposed method reduces ghost artifacts more than previous methods. The quantitative ghost-free evaluation of the proposed method is also less than others.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.4 s.316
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• pp.35-43
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• 2007

With the current trend of digital convergence in mobile phone, imaging devices such as cameras, displays and beam-projectors have been made smaller and become into mobile phones. Especially, built-in beam-projectors (we call it mobile beam-projector hereafter) have been developed to overcome small screen size of mobile display and to provide the realistic image while watching movies or broadcasting. However, mobile beam-projector can project an original image on various colored-screen, different from general data projector with white screen, thereby degrading the image quality of projected images. Therefore, this paper proposed a method of correcting projected images on colored-screens by adapting color constancy theory that has been mainly used for illumination estimation.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.179-184
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• 2003

Total 7 moors, Yong-neup on Mt. Daeam, Chilbo Mt. moor, Dogapsa-neup on Mt. Wolchul, Wangdeungiae-neup on Mt. Jiri, Mujechi-neup on Mt. Jungjok, Buljae-neup on Mt. Kyungak and Geoinri-neup on Dongsang, were investigated by literatures and survey. Distribution, conditions, and similarity of dominant species and Orchidaceae on moor were analyzed. The results are follows; There are total 46 wetland plant species observed more than twice from 7 moors. The plants classified as constancy class V, which are appeared more than 80%, are Iris ensata var. spontane, Juncus effusus var. decipiens, Sanguisorba tenuifolia var. alba, Habenaria linearifolia, Sium ninsi, Lobelia sessilifolia, Lastrea theiyptoris, and Eupatorium chinensis var. simplicifolium. Highly appearing Orchidaceae, which was classified to constancy class IV plant, are Habenaria linearifolia, Pogonia japonica, Eipactis thunbergii, and Platanthera mandarinorum. They are the typical index plants of the moors. Habitual environment of Habenaria radiate and Platanthera hologlottis can be affected by environmental aspects such as latitude, altitude and the water quality. However those of Habenaria linearifolia, Epipactis thunbergii, and Pogonia japonica are not affected by latitude and altitude, but may be determined by water condition of wetland. As the result of similarity index analysis for appearance of Orchidaceae identifying each moors in the view of species composition, swamps at Dogapsa-neup and Buljae-neup are very similar. However Yong-neup is totally different from those of Dogapsa-neup and Buljae-neup. Yong-neup had shown the high similarity indices of 0.85 and 0.75 with Wangdeungiae-neup and Mujechi-neup, respectively. Growth properties of wild Orchidaceae at wetland were almost similar. Platanthera mandarinorum and Liparis kumokiri had characteristics of good adaptability. Most of them need light. Pogonia was the only long-day plant. The flowering time of these Orchidaceae was from May to September.

• Journal of The Korean Association For Science Education
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• v.31 no.6
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• pp.998-1008
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• 2011

The purpose of this study is to develop the criteria for measuring the observation abilities of elementary school students. Object, viewpoint and mental demand constitute the evaluation criteria of observation abilities. Object domain was classified into two- and three-dimensional figures, while viewpoint was classified into constancy and variety of views. Mental demand covered 2 through 5. The assesment tool based on the threedimensional criteria was developed for the lower, middle and upper grades of 166 elementary school students. Results from this study were as follows. These students' scores were significantly different in the classification by each dimension and distinguishable between the grades. They scored high on two-dimensional figures, constancy of view and lower mental demand, and the upper grade students' scores were higher than the lower ones in all dimensions. Therefore, the evaluation criteria developed in this study can be used effectively for measuring the observation abilities of elementary school students. Implication for this study was determined to be the development of a valid and reliable test for observation abilities of elementary school students.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.28-35
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• 2014

Surveillance cameras in national border and coastline area often occur the video distortion because of rapidly changing weather and light environments. It is positively necessary to enhance the distorted video quality for keeping surveillance. In this paper, we propose an adaptive video enhancement algorithm in the various environment changes. To solve an unstable performance problem of the existing method, the proposed method is based on Retinex algorithm and uses enhanced curves which is adapted in foggy and low-light conditions. In addition, we mixture the weighted HSV color model to keep color constancy and reduce noise to obtain clear images. As a results, the proposed algorithm improves the performance of well-balanced contrast enhancement and effective color restoration without any quality loss compared with the existing algorithm. We expect that this method will be used in surveillance camera systems and offer help of national defence with reliability.