• Kyungpook Mathematical Journal
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• v.56 no.4
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• pp.1103-1113
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• 2016

In this paper, we study a directed simple graph ${\Gamma}_S(N)$ for a near-ring N, where the set $V^*(N)$ of vertices is the set of all left N-subsets of N with nonzero left annihilators and for any two distinct vertices $I,J{\in}V^*(N)$, I is adjacent to J if and only if IJ = 0. Here, we deal with the diameter, girth and coloring of the graph ${\Gamma}_S(N)$. Moreover, we prove a sufficient condition for occurrence of a regular element of the near-ring N in the left annihilator of some vertex in the strong zero-divisor graph ${\Gamma}_S(N)$.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.130-131
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• 2000

One of the more promising proposals for guiding and focusing neutral atoms involves dark hollow laser beams. When the frequency of the laser is detuned to the blue of resonance, the dipole force the atoms feel in the light confines them to the dark core where the atoms can be transported with minimal interaction with the light. The ability of the all-light atom guides to transport large number of ultracold atoms for long distances without physical walls leads to the possibility of a versatile tool for atom lithography, atom interferometry, atomic spectroscopy as well as for transporting and manipulating Bose-Einstein condensates. Furthermore since the atoms transported in all-light atom guides do not come into contact with matter, they can in principle be used to transport antimatter as well. The ability to vary the core size of the hollow beam makes the all-light atom guide potentially useful for focusing neutral atoms. The atoms could be focused as tight as the core size of the hollow beam at its waist. This new focusing scheme, called the atom funnel, would not show spherical and chromatic aberrations that conventional harmonic focusing suffers from. (omitted)

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.12
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• pp.2315-2325
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• 2011

We propose a novel reduced-state maximum-likelihood sequence detection (MLSD) structure using the Viterbi algorithm based on the second-order Volterra kernel modeling nonlinear distortion due to square law detection of multipath channels commonly occurring in chromatic dispersion (CD) or polarization mode dispersion (PMD) in optical communication systems. While all existing MLSD methods for square-law detection receivers are based on direct computation of branch metrics, the proposed algorithm provides an efficient and structured way to implement reduced-state MLSD with almost the same complexity of a MLSD for linear channels. As a result, the proposed algorithm reduces the number of parameters to be estimated and the complexity of computation.

• Journal of Korean Institute of Industrial Engineers
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• v.18 no.2
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• pp.43-49
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• 1992

Edge coloring problem is to find a minimum cardinality coloring of the edges of a graph so that any pair of edges incident to a common node do not have the same colors. Edge coloring problem is NP-hard, hence it is unlikely that there exists a polynomial time algorithm. We formulate the problem as a covering of the edges by matchings and find valid inequalities for the convex hull of feasible solutions. We show that adding the valid inequalities to the linear programming relaxation is enough to determine the minimum coloring number(chromatic index). We also propose a method to use the valid inequalities as cutting planes and do the branch and bound search implicitly. An example is given to show how the method works.

• Journal of information and communication convergence engineering
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• v.20 no.4
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• pp.235-241
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• 2022

A dispersion map was proposed to improve the compensation effect of a distorted WDM (wavelength division multiplexed) channel in a dispersion-managed link coupled with optical phase conjugation. The dispersion map is an origin-symmetric structure around the optical phase conjugator in the middle of the transmission path. In addition, the dispersion map has a form in which a constant dispersion accumulation pattern is repeated regularly. Through simulation, we confirmed that the application of the origin-symmetric dispersion map with a repetitively shaped configuration was more effective in compensating for the distorted WDM channel than in the dispersion-managed link with a conventional dispersion map. In addition, we confirmed that the compensation effect could be increased when the cumulative dispersion distribution of the origin-symmetric distribution map had a positive value in the first half section and a negative value in the second half section. Further, we observed that as the number of repeated dispersion accumulation patterns increased, the residual dispersion per span should also be increased.

• Textile Coloration and Finishing
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• v.23 no.4
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• pp.241-249
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• 2011

Cotton fabrics was treated with persimmon juice by padding and their dyeability and functionality were assessed including antibacterial activity and deodorization ratio. The merit of padding-based dyeing was easier color reproduction over traditional hand dyeing where various colors and color fastness to light and laundering are hard to obtain. With larger number of padding, the dyed fabrics showed deeper red-yellow colors, which had low brightness and high chromatic colors. The dyed cotton fabrics had a perspiration fastness of 4~5 rating, a rubbing fastness of 3~4 rating, and a washing fastness of 4 rating, As the number of padding and exposed time to sunlight or UV light increase, the values of K/S and ${\Delta}E$ increased and the colors became much deeper gradually. The color development had completed about 70 hours exposure to UV. Among the light sources, the dyed fabrics exposed to UV light showed deeper yellow-red color than those of exposed to sunlight. The cotton fabrics treated with premordants like Al, Cr, Cu, and Sn revealed strong yellow colors, especially the fabrics treated with Fe mordant showed greenish red-yellow colors. As the padding times of dyeing with persimmon juice increased, stiffness and water repellent property were enhanced in warp and weft directions, respectively. Also, the dyed fabrics have good antibacterial activity and deodorization.

• Fashion & Textile Research Journal
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• v.17 no.5
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• pp.828-837
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• 2015

The results of the analysis of dyed rayon fabrics treated with persimmon juice by padding are as follows. Rayon fabrics were dyed repeatedly with persimmon juice by a padding mangle for the development of dyeability. The merits of padding-based dyeing were easier color reproduction (versus traditional hand dyeing) of hard to obtain colors and color fastness to light and laundering. The add on weight increased with the number of padding times, and the color of the dyed fabrics had red-yellow colors with low brightness and high chromatic colors. Properties of fabrics treated with persimmon juice were: $2^{nd}$ level of light resistance, $4^{th}-5^{th}$ perspiration fastness levels, rubbing fastness, and $3^{rd}-4^{th}$ washing fastness levels. Dyed fabrics exposed to UV light have a deep yellow-red color that increased lightness and darken when exposed to sunlight. Rayon fabrics of a treated premordant indicated strong yellow colors, especially fabrics with Fe mordant indicated greenish red-yellow colors. The direction of the weft and warp increased and improved water-repellent qualities that increased with the number of dyeing padding times and persimmon juice; however, there was less anti-crease resistance. In addition, fabrics had good antibacterial activity and deodorization.

• Journal of the Korea Society of Computer and Information
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• v.18 no.5
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• pp.113-120
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• 2013

This paper proposes an algorithm that proves an NP-complete 4-color theorem by employing a linear time complexity where $O(n)$. The proposed algorithm accurately halves the vertex set V of the graph $G=(V_1,E_1)$ into the Maximum Independent Set (MIS) $\bar{C_1}$ and the Minimum Vertex Cover Set $C_1$. It then assigns the first color to $\bar{C_1}$ and the second to $\bar{C_2}$, which, along with $C_2$, is halved from the connected graph $G=(V_2,E_2)$, a reduced set of the remaining vertices. Subsequently, the third color is assigned to $\bar{C_3}$, which, along with $C_3$, is halved from the connected graph $G=(V_3,E_3)$, a further reduced set of the remaining vertices. Lastly, denoting $C_3$ as $\bar{C_4}$, the algorithm assigns the forth color to $\bar{C_4}$. The algorithm has successfully obtained the chromatic number ${\chi}(G)=4$ with 100% probability, when applied to two actual map and two planar graphs. The proposed "four color algorithm", therefore, could be employed as a general algorithm to determine four-color for planar graphs.

• Journal of the Korean Society of Costume
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• v.50 no.4
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• pp.53-61
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• 2000

The purpose of this study is to classify the characteristics of color communication tools and the color range applied in the Korean fashion industry. To collect the color sample and related references, a questionnaire was distributed during the time period, December, 1995 to June, 1996. From the responses, 2641 color samples used by 109 domestic brands, from 1993 spring/summer to 1996 spring/summer, were collected and analyzed. The data was measured by L*a*b*, and the H V/C formula found in the Munsell notation was used to calculate the data. To classify the color range served for the fashion industry, the distribution of colors are analyzed by difference of season and fabric. The results of this study are as follows : 1. Dominant colors in the Korean fashion industry are Red, Yellow-red, Yellow, purple-blue and low chromatic range colors. 2. While high value colors, such as pale, light greyish, light, dull, dark and vivid tone colors, are dominant in the spring/summer season, low value colors, such as greyish, dark greyish. and deep tone colors and warm colors such as Red, Yellow-red, are prevalent in the fall/winter season. 3. The number of colors commonly used for color planning is less than 20 colors, and both hue and tone are considered important when making color selections. 4. All brands take consumers' color preferences into consideration for color planning, and most of them also take color trends into account. 5. Hue and tone color characteristics analyzed by types of fabrics show more seasonal influence than the fabric itself.

• Fashion & Textile Research Journal
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• v.10 no.6
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• pp.1036-1044
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• 2008

This research from analyzing dyed silk fabrics treated with persimmon juice by padding concludes as follows : The add on is increased as the number of padding increase and the color of the dyed fabrics holds red-yellow colors which has low brightness and high chromatic colors. The fabrics dyed with persimmon juice have properties such as 2nd grade of light fastness, 4~5th grade of perspiration fastness and rubbing fastness, and 3~4th grade of washing fastness. The dyed fabrics exposed to UV light have deeper yellow-red color than things exposed to sunlight. The silk fabrics treated premordants have shown strong yellow colors, especially the fabrics added Fe mordant have shown greenish red-yellow colors. As the padding times of dyeing with persimmon juice are increased, strength and water-repellent property are enhanced along warp and weft direction respectively but anti-crease property is decreased. Also, the dyed fabrics have good antibacterial activity and deodorization.