• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10a
• /
• pp.178-180
• /
• 2003

최소 걸침 나무는 널리 알려진 순회 판매원 문제와 같이 전통적인 최적화 문제 중에 하나이다. 특히나 최소 걸침 나무와는 달리 차수 제약 최소 걸침 나무의 경우는 일반적으로 NP-hard 문제로 알려져 있다. 이러한 NP-hard 문제를 해결하기 위한 다양한 접근법들이 소개되었는데 유전 알고리즘은 효율적인 방법 중에 하나로 알려져 있다. 유전 알고리즘과 같이 진화에 기반을 둔 알고리즘을 어떤 문제에 적응하기 위해서 가장 우선적으로 고려되어야 하는 것은 해를 어떻게 표현할 것인가 인데 본 논문에서는 차수 제약 최소 걸침 나무를 해결하기 위한 새로운 트리 표현법을 제안한다.

• Communications of the Korean Mathematical Society
• /
• v.28 no.4
• /
• pp.857-863
• /
• 2013

In this paper, we prove that the total domination number of a $P_6$-free graph of order $n{\geq}3$ and minimum degree at least one which is not the cycle of length 6 is at most $\frac{n+1}{2}$, and the bound is sharp.

• Journal of KIEE
• /
• v.10 no.1
• /
• pp.23-27
• /
• 2000

The relative degree one and weakly minimum-phase conditions have been major obstacles for passification of the given system. In this paper, a dynamic output feedback passifier which can remove the obstacles is presented. The proposed method does not require any modification of the given output except just adding a new term. Therefore, the scheme is more suitable for output feedback passification.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.4
• /
• pp.1033-1043
• /
• 1998

In this paper, we present an improved multicasting path assignment algorithm based on the minimum cost spanning tree. In the method presented in this paper, a multicasting path is assigned preferentially when a node to be received is found among the next degree nodes of the searching node in the multicasting path assignment of the constrained steiner tree (CST). If nodes of the legacy group exist between nodes of the new group, a new path among the nodes of new group is assigned as long as the nodes may be excluded from the new multicasting path assignment taking into consideration characteristics of nodes in the legacy group. In assigning the multicasting path additionally, where the source and destination nodes which can be set for the new multicasting path exist in the domain of identical network (local area network) and conditions for degree constraint are satisfied, a method of producing and assigning a new multicasting path is used. The results of comparison of CST with MCSTOP, MCSTOp algorithm enhanced performance capabilities about the communication cost, the propagation delay, and the computation time for the multicasting assignment paths more than CST algorithm. Further to this, research activities need study for the application of the international standard protocol(multicasting path assignment technology in the multipoint communication service (MCS) of the ITU-T T.120).

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.7
• /
• pp.85-93
• /
• 2011

The Vertex Coloring Problem hasn't been solved in polynomial time, so this problem has been known as NP-complete. This paper suggests linear time algorithm for Vertex Coloring Problem (VCP). The proposed algorithm is based on assumption that we can't know a priori the minimum chromatic number ${\chi}(G)$=k for graph G=(V,E) This algorithm divides Vertices V of graph into two parts as independent sets $\overline{C}$ and cover set C, then assigns the color to $\overline{C}$. The element of independent sets $\overline{C}$ is a vertex ${\upsilon}$ that has minimum degree ${\delta}(G)$ and the elements of cover set C are the vertices ${\upsilon}$ that is adjacent to ${\upsilon}$. The reduced graph is divided into independent sets $\overline{C}$ and cover set C again until no edge is in a cover set C. As a result of experiments, this algorithm finds the ${\chi}(G)$=k perfectly for 26 Graphs that shows the number of selecting ${\upsilon}$ is less than the number of vertices n.

• Journal of Power System Engineering
• /
• v.5 no.3
• /
• pp.104-113
• /
• 2001

This paper describes a precise position synchronous control of two axes rotating system using BLDC motors and a cooperative control based on decoupling technique and PI control law. The system is required performances both good speed following and minimum position synchronous errors simultaneously. To accomplish these goals, the three kinds of controllers are designed. At first, the current and speed controller are designed very simply to compensate the influences of disturbances and to follow up speed references quickly. Especially, the two degree of freedom PI controller is used considering both good tracking for speed reference input and quick rejection of disturbances in speed controller. Finally, a position synchronous controller is designed as a simple proportional controller to minimize position synchronous errors. The validity of the proposed method is confirmed through some numerical simulations. Moreover, the results are compared to the conventional master-slave control ones to show the effectiveness of the proposed system.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.18 no.5
• /
• pp.615-621
• /
• 1994

This study was carried out to investigate the effect of clothing habit on physiological adaptation to the change of season. The survey of clothing weight in fall '||'&'||' winter for 2 years, the frequency of cold infection in winter and degree of fatigue was performed with 110 female high school students. The actual condition of clothing and the correlations between clothing weight and cold infection, and between the clothing weight and degree of fatigue were suveyed. The results are followed as; 1. The clothing insulation was nearly same to indoor standard clothing insulation in H hun wearing normal clothing, but was higher 2 clo in S hun clothed uniform. Especially in spite of similar enviromental condition the clothing weight, minimum '||'&'||' maximum and variation of clothing weight for 2 years were showed to be heavier in S hun than H hun. Also indoor thermal sensation felt by the subjects indicated "cold", and the difference between clothing insulation and standard clothing insulation showed increase gradually. 2. L group was indicated to be lower in cold infaction ratio than M '||'&'||' H group, and the correlation between clothing group and cold infection ratio was recognized to be significant (p<0.05). And H hun and L-H group showed to be lower in cold infection ratio than S hun, H-L group. 3. The coefficience between clothing weight and degree of fatigue was recognized to be significant (p<0.05).

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.1254-1263
• /
• 1993

Representing knowledge uncertainty , aggregating evidence confidences , and propagation uncertainties are three key elements that effect the ability of a rule-based expert system to represent domains with uncertainty . Fuzzy set theory provide a good mathematical tool for representing the vagueness associated with a variable when , as the condition of a rule , it only partially corresponds to the input data. However, the aggregation of ANDed and Ored confidences is not as simple as the intersection and union operators defined for fuzzy set membership. There is, in fact, a certain degree of compensation that occurs when an expert aggregates confidences associated with compound evidence . Further, expert often consider individual evidences to be varying importance , or weight , in their support for a conclusion. This paper presents a flexible approach for evaluating evidence and conclusion confidences. Evidences may be represented as fuzzy or nonfuzzy variables with as associat d degree of certainty . different weight can also be associated degree of certainty. Different weights can also be assigned to the individual condition in determining the confidence of compound evidence . Conclusion confidence is calculated using a modified approach combining the evidence confidence and a rule strength. The techniques developed offer a flexible framework for representing knowledge and propagating uncertainties. This framework has the potention to reflect human aggregation of uncertain information more accurately than simple minimum and maximum operator do.

• Korean journal of food and cookery science
• /
• v.6 no.4 s.13
• /
• pp.15-19
• /
• 1990

Gelatinization properties of potato starches from Irish Cobbler (the dry type), Shepody and Superior (the intermediate type) and Dejima (the moist type) were investigated. The minimum moisture contents for gelatinization of starches was 45%. When the moisture contents percentage was $45{\sim}60%$, the degree of gelatinization of potato starches was higher in Dejima than in Irish Cobbler, on the other when it was 70%, all of kind were almost similar. The gelatinization temperature of starches was $65^{\circ}C$, When the temperature was $65^{\circ}C$, degree of gelatinization was highest in Dejima and lowest in Irish Cobbler, on the other hand when it was $75^{\circ}C$. highest in Irish Cobbler and lowest in Shepody.

• Journal of Surface Science and Engineering
• /
• v.46 no.1
• /
• pp.48-53
• /
• 2013

In the present work, it was investigated a behavior of hydrogen embrittlement at the subsurface zones of 590 DP steels by using the micro-Vickers hardness test. The micro-Vickers hardnessess of DP steels were measured to evaluate the degree of embrittlement as the effective hardening depths of subsurface zones with hydrogen charging conditions. The results showed that the distributions of micro-Vickers hardness in width varied from maximum hardness 239.5 Hv to minimum hardness 174 Hv, while the depth of effective hardening layer at the subsurface zones of DP steels was from $320{\mu}m$ to $460{\mu}m$ with hydrogen charging conditions, respectively. It was proposed that the distribution of microhardness be used as the evaluation index of the degree of embrittlement. But the variations of martensite volume fractions were not affected along depth of hardening at the same changing time, hydrogen charging times were appeared as an effective factor of the degree of embrittlement. Therefore, the micro-Vickers hardness test is an attractive tool for evaluation of hydrogen embrittlement at the subsurface zones of these DP steels.