• 한국가구학회지
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• 제26권3호
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• pp.286-290
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• 2015

The wood veneers were clearly rainbow-colored with natural dyes. As shown through Korean-style jacket with stripes of multi-colors beyond traditional obang colors (red, blue, yellow, black and white colors), eco-friendly coloring methods representing Korean colors familiar from old times could be used nobly by coloring natural wood veneer being raw material of wood products. In terms of industrialization, the study to manifest korean color, substituting chemical stains such as dye and pigment, would be necessary. In order to realize this purpose, the study about economical dyeing materials and characteristics, that is, mordant, dyeing and drying techniques showing environment-friendly coloring and high coloration level ought to be followed. In addition to this, investigating discoloration transition by fading test for interior and exterior uses would have to be carried out.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.5800-5818
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• 2018

Interference may occur when several co-located wireless body area networks (WBANs) share the same channel simultaneously, which is compressed by resource scheduling generally. In this paper, a QoS-aware Adaptive Coloring (QAC) scheduling algorithm is proposed, which contains two components: interference sets determination and time slots assignment. The highlight of QAC is to determine the interference graph based on the relay scheme and adapted to the network QoS by multi-coloring approach. However, the frequent resource assignment brings in extra energy consumption and packet loss. Thus we come up with a launch condition for the QAC scheduling algorithm, that is if the interference duration is longer than a threshold predetermined, time slots rescheduling is activated. Furthermore, based on the relative distance and moving speed between WBANs, a prediction model for interference duration is proposed. The simulation results show that compared with the state-of-the-art approaches, the QAC scheduling algorithm has better performance in terms of network capacity, average delay and resource utility.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1375-1377
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• 2002

New graph coloring problems are discussed as models of a multihop network in this report. We consider a total scheduling problem, and prove that this problem is NP-hard. We propose new scheduling models of a multi-hop network for CDMA system, and show the complexity results of the scheduling problems.

• 전자공학회논문지A
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• 제30A권12호
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• pp.135-146
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• 1993

A ner general multi-layer area router, called DINOSAUR, is presented in this paper. DINOSAUR can route various types of routing areas, such as L-shaped channel, switchbox with/without obstacles, and rectilinear area with/without internal modules/terminals. The DINOSAUR algorithm consists of three major stages: layerless maze routing, layering by coloring, and rip-up and reroute. In layerless maze roution stage, the route of each net is determined by modified maze algorithm without taking the conflicts(short. circuits) into account. In layering by coloring stage, the layer of each net is determinde by a heuristic coloring algorithm. When the conflicts are not removed, rip-up and reroute process is invoded. In rip-up and reroute stage, the conflicts are removed iteratively. Many test cases have been run, and on all the benchmark data known in the literature DINOSAUR has performed either better than or comparable to the other routers.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권3호
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• pp.194-197
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• 2002

This paper considers the problem of routing connections in a optical multi tree networks using WDM (Wavelength Division Multiplexing), where each connection between a pair of nodes in the network is assigned a path through the network and a wavelength on that path, so that connections whose paths share a common link in the network are assigned different wavelengths. The problem of optimal coloring of the paths on the optical multi-networks is NP-hard[1], but if that is the coloring of all paths, then there exists efficient polynomial time algorithm. In this paper, using a "divide & conquer" method, we give efficient algorithm to assign wavelengths to all the paths of a tree network based on the theory of [7]. Here, our time complexity is 0(n4log n).

• 대한수학회논문집
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• 제19권3호
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• pp.577-584
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• 2004

In a 4-valent multi 3-gon graph, every cut-through curve forms a simple closed circuit. Hence it is a weak arrangement of simple curves that is defined by Branko Grunbaum. In this paper, we study the edge properties of the 4-valent multi 3-gon graphs from the point of view of arrangement, and we show that they are 3 colorable.

• Journal of applied mathematics & informatics
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• 제11권1_2호
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• pp.305-316
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• 2003

Recently, an iterative algorithm for finding the interior eigenvalues of a definite matrix by CG-type method has been proposed. This method compares to the inverse power method. The given matrices A, and B are assumed to be large and sparse, and SPD( Symmetric Positive Definite) The CG scheme for the optimization of the Rayleigh quotient has been proven a very attractive and promising technique for large sparse eigenproblems for smallest eigenvalue. Also, it is very amenable to parallel computations, like the CG method for the linear systems. A proper choice of the preconditioner significantly improves the convergence of the CG scheme. But for parallel computations we need to find an efficient parallel preconditioner. Our candidates we ILU(0) in the wave-front order, ILU(0) in the multi-coloring order, Point-SSOR(Symmetric Successive Overrelaxation), and Multi-Color Block SSOR preconditioner. Wavefront order is a simple way to increase parallelism in the natural order, and Multi-coloring realizes a parallelism of order(N), where N is the order of the matrix. Another choice is the Multi-Color Block SSOR(Symmetric Successive OverRelaxation) preconditioning. Block SSOR is a symmetric preconditioner which is expected to minimize the interprocessor communication due to the blocking. We implemented the results on the CRAY-T3E with 128 nodes. The MPI (Message Passing Interface) library was adopted for the interprocessor communications. The test problem was drawn from the discretizations of partial differential equations by finite difference methods. The results show that for small number of processors Multi-Color ILU(0) has the best performance, while for large number of processors Multi-Color Block SSOR performs the best.

• 한국정보통신학회논문지
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• 제9권5호
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• pp.1102-1110
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• 2005

본 논문에서는 기존 복셀 칼라링 기법에서의 색상 일관성에 대한 문턱값 문제를 해결하기 위한 개선된 복셀 칼라링 기법을 제안하였다. 제안 기법에서는 표면 복셀에 대한 색상 일관성의 문턱값을 내부 복셀의 색상 일관성 값으로 대체함으로써 복셀 칼라링의 반복 회수가 증가함에 따라 개별 표면 복셀에 대한 최적의 문턱값을 찾아가도록 하였다. 또한 그래프 절단 기법을 적용하여 주위 복셀을 제거 판단에 함께 고려함으로써 표면 잡음을 감소시켰다.

• Journal of applied mathematics & informatics
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• 제41권3호
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• pp.511-524
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• 2023

An L(p₁, p₂, p₃, . . . , p_m)-labeling of a graph G is an assignment of non-negative integers, called as labels, to the vertices such that the vertices at distance i should have at least pi as their label difference. If p₁ = 4, p₂ = 3, p₃ = 2, p₄ = 1, then it is called a L(4, 3, 2, 1)-labeling which is widely studied in the literature. A L(4, 3, 2, 1)-path coloring of graphs, is a labeling g : V (G) → Z⁺ such that there exists at least one path P between every pair of vertices in which the labeling restricted to this path is a L(4, 3, 2, 1)-labeling. This concept was defined and results for some simple graphs were obtained by the same authors in an earlier article. In this article, we study the concept of L(4, 3, 2, 1)-path coloring for complete bipartite graphs, 2-edge connected split graph, Cartesian product and join of two graphs and prove an existence theorem for the same.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권4호
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• pp.1535-1554
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• 2016

This paper proposes a novel channel assignment scheme called multi-cluster based dynamic channel assignment (MC-DCA) to improve system performance for the downlink of dense femtocell networks (DFNs) based on orthogonal frequency division multiple access (OFDMA) and frequency division duplexing (FDD). In order to dynamically assign channels for femtocell access points (FAPs), the MC-DCA scheme uses a heuristic method that consists of two steps: one is a multiple cluster assignment step to group FAPs using graph coloring algorithm with some extensions, while the other is a dynamic subchannel assignment step to allocate subchannels for maximizing the system capacity. Through simulations, we first find optimum parameters of the multiple FAP clustering to maximize the system capacity and then evaluate system performance in terms of the mean FAP capacity, unsatisfied femtocell user equipment (FUE) probability, and mean FAP power consumption for data transmission based on a given FUE traffic load. As a result, the MC-DCA scheme outperforms other schemes in two different DFN environments for commercial and office buildings.