• Journal of applied mathematics & informatics
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• 제24권1_2호
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• pp.313-323
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• 2007

The equitable total chromatic number ${\chi}_{et}(G)$ of a graph G is the smallest integer ${\kappa}$ for which G has a total ${\kappa}$-coloring such that the number of vertices and edges in any two color classes differ by at most one. In this paper, we determine the equitable total chromatic number of one class of the graphs.

• Journal of the Optical Society of Korea
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• 제16권3호
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• pp.215-220
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• 2012

In an earlier work, we proposed the chromatic dispersion monitoring technique of non-return to zero (NRZ) signal based on clock-frequency component (CFC) through numerical simulations. However, we have not yet shown any experimental demonstration or analytic derivation of it. In this paper, we show an experimental demonstration and analytic derivation of the proposed chromatic dispersion monitoring technique. We confirm that the experimental results and the analytic results correspond with the simulation results. We also demonstrate that monitoring range and accuracy can be improved by using a simple clock-extraction method.

• International Journal of Computer Science & Network Security
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• 제21권9호
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• pp.79-85
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• 2021

The locating-chromatic number denote by 𝛘_𝐿(G), is the smallest t such that G has a locating t-coloring. In this research, we determined locating-chromatic number for subdivision of certain barbell operation of origami graphs.

• Korean Journal of Mathematics
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• 제27권2호
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• pp.525-534
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• 2019

Let $P(G,{\lambda})$ denote the number of proper vertex colorings of G with ${\lambda}$ colors. The chromatic polynomial $P(C_n,{\lambda})$ for the cycle graph $C_n$ is well-known as $$P(C_n,{\lambda})=({\lambda}-1)^n+(-1)^n({\lambda}-1)$$ for all positive integers $n{\geq}1$. Also its inductive proof is widely well-known by the deletion-contraction recurrence. In this paper, we give this inductive proof again and three other proofs of this formula of the chromatic polynomial for the cycle graph $C_n$.

• 한국콘텐츠학회논문지
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• 제10권7호
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• pp.107-114
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• 2010

색채는 빛을 통해 인간이 시각적으로 느끼는 감각으로, 사람이 인지할 수 있는 색채인 유채색(chromatic color area)과 무채색(achromatic color area)으로 구분할 수 있다. 유채색은 색상, 명도, 채도의 속성이 존재하지만 무채색은 유채색의 속성 중 명도는 있지만 색상과 채도의 성격을 갖지 않는다. 따라서 인간의 시각에 기초하여 인간이 색채를 인지할 수 있는 영역과 인지하지 못하는 영역을 분리하는 것은 중요하다. 본 논문에서는 영상의 유채영역인 색상영역과 무채영역인 비색상영역을 분리하는 함수를 도출한다. 먼저 입력된 RGB 컬러공간의 입력영상을 인간의 시각을 고려한 HSI 컬러공간으로 변환하여 이진영상을 구한 후 색상 영역(ROC: Region of chromatic)과 비색상 영역(ROA:Region of achromatic)으로 분류하기 위한 함수를 도출한다. 일반영상에서 ROC와 ROA의 영역을 분리하기는 어려우므로 색상영역과 비색상영역을 도출하기 위해 색상값의 변화가 크지 않고 명암과 채도가 변화하는 그레디언트 영상을 생성하여 함수를 도출한다. 성능평가는 실험영상과 일반영상의 결과영상을 비숙련가 50인에게 주관적 화질평가를 실시하였으며 제안방법은 기존의 방법에 비해 27.5~32.96%가 개선되었다.

• 한국컴퓨터정보학회논문지
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• 제19권5호
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• pp.19-25
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• 2014

본 논문은 평면상의 거리가 1인 인접 정점들에 대해 서로 다른 색을 칠할 경우 최대로 필요한 색인 채색수를 찾는 문제를 연구하였다. 지금까지 채색수 상한 값은 $4{\leq}{\chi}(G){\leq}7$로 알려져 있으며, Hadwiger-Nelson은 ${\chi}(G){\leq}7$, Soifer는 ${\chi}(G){\leq}9$를 제안하였다. 먼저, 최소로 필요로 하는 채색수를 구하는 알고리즘을 제안하고, Hadwiger-Nelson의 정육각형 그래프를 대상으로 채색수를 구한 결과 ${\chi}(G)=3$이 될 수 있음을 보였다. Hadwiger-Nelson의 정육각형 그래프를 12개 인접 정점으로 가정할 경우 ${\chi}(G)=4$를 구하였다. 또한, Soifer의 8개 인접 정점 정사각형 그래프에 대해 채색수를 구한 결과 ${\chi}(G)=4$임을 보였다. 결국, 제안된 알고리즘은 최소 차수 정점부터 색을 배정하는 단순한 다항시간 규칙을 적용하여 평면의 최대 채색수는 ${\chi}(G)=4$임을 제안한다.

• 패션비즈니스
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• 제12권5호
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• pp.94-110
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• 2008

The main objective of this research was to understand the characteristics of separation color coordination of contemporary female fashion through the analysis of 'pre-a-porter Collections' of four collections (i. e. cities) - Paris, Milan, New York, London - from the periods of 2004 S/S to 2008/9 A/W. The data collection of 265 was done by reviewing 'pre-a-porter Collections' magazine and total 265 observations were made. Statistical analysis of frequency and also qualitative interpretation of separation color coordination characteristics were completed. The main findings were; (1) In separation color coordination of contemporary women's fashion collections, there were three main types of color scheme which were classified into seven detailed categories of color combination. First was the achromatic color & one chromatic separation color scheme which was classified into four categories of - black & white, black & grey, white & grey, and grey & grey - color combination. Second was the chromatic colors & one achromatic separation color scheme which classified into two categories of achromatic & chromatic color & one achromatic separation color combination, and chromatic colors & one achromatic separation color combination. Third was chromatic colors and one chromatic separation color combination. (2) The achromatic colors and one chromatic separation color scheme showed two phases of reinforcing the strong and modern image, or softening the hard and dull image of achromatic color combination. In color schemes which used more than two chromatic colors, the separation color frequently converted the tedious and monotonous fashion image, which caused by identical or similarity in color or tone harmony, into more attractive and interesting. (3) In conclusion, through the various use and coordination of various color schemes, color harmony and separation colors, the separation color coordination in contemporary female fashion has been suggested the effective way of color combination which can lead the visual pleasure and the vitality along with the unity and the harmony. This characteristics can create various images and visual diversity for fashion. The types and the use of color scheme and separation color showed different trends in four collections.

• 대한수학회논문집
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• 제34권2호
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• pp.391-399
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• 2019

Let R be a commutative ring with identity and let M be an R-module. The main purpose of this paper is to calculate the chromatic number of the zero-divisor graphs over modules.

• Tribology and Lubricants
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• 제24권1호
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• pp.7-13
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• 2008

In this work, a simple and low cost sensor technique is proposed to test oil color in real time using in-line sensor. It is presented to use a ratio of intensity in red wavelength range to intensities of green and blue wavelength ranges (defined as a 'chromatic ratio') in order to estimate the oil color change. The proposed sensor technique is realized by irradiating a white LED as light source and a RGB color sensor as photoreceiver, and the chromatic ratio of various types of used oils are measured. The results show that chromatic ratio generally reflects chemical deterioration of oil, including oil oxidation and thermal degradation. It is concluded that the proposed sensor could be used for an effective oil monitoring technology.

• Journal of the Optical Society of Korea
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• 제16권4호
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• pp.336-342
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• 2012

A low-cost optimal double-prism method is proposed by using the developed MATLAB program to correct chromatic aberration. We present an efficient approach to choose a couple of low-cost glasses to obtain a low aberration double prism. The doublet prisms were made of two lead-free glasses. The relative partial dispersion of the two lead-free glasses is identical and their Abbe numbers are different greatly. The proposed design aims to minimize chromatic aberration, such as in apochromats, for paraxial ray tracing. Finally, an optimization design for real ray tracing can be evaluated by the chromatic aberration curve with a minimal area.