• 대한수학회논문집
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• 제28권4호
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• pp.857-863
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• 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
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• 제10권1호
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• pp.23-27
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• 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.

• 한국정보처리학회논문지
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• 제5권4호
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• pp.1033-1043
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• 1998

본 논문에서는 최소 비용 신장 트리(minimum cost spanning tree를 기반으로 최적 경로를 지원할 수 있는 새로운 멀티케스트 경로 배정 알고리즘을 제안하였다 본 논문에서 제안한 MCSTOP(Multicasting Path Assignment using the MInimum Cost Spanning Tree and the Optimum Path Generation) 알고리즘은 송신 노드나 이미 선정된 노드의 하위 노드들 중에서 새로운 그룹의 수신 노드가 발견되면 우선적으로 멀티캐스트 경로를 배정하는 방법을 적용하였다. 새로운 그룹의 멀티캐스트 배정과정에서 새로운 그룹의 수신 노드들 사이에 타 그룹의 노드가 발생될 수 있다. 이러한 경우가 발생되면, MCSTOP 알고리즘에서는 새로운 그룹의 송신 노드와 수신 노드가 동일한 네트워크 영역(예. LAN 영역)과 치수 제한조건이 만족되면 새로운 가상 경로를 생성하여 최적 경로를 배정하도록 하였다. MCSTOP 알고리즘은 가상 경로로 설정된 노드들 사이에 존재하는 타 그룹 노드가 네트워크에서 탈퇴하여도 영향을 받지 않게 되므로, 새로운 그룹에 대한 멀티캐스트 경로의 재구성을 최소화 시킬 수 있었다. 또한, 검증 결과 MCSTOP알고리즘은 멀티 캐스트 배정 경로를 위한 계산시간, 통신비용 그리고 데이터 전달지연시간 등이 CST(Constrained Steiner Tree) 알고리즘보다 성능 향상을 보였다. 추후 연구 사항으로는 데이터 회의를 지원하기 위한 그룹 통신 프로토콜로써 ITU-TT.120 시리즈의 MCS(Multipoint Communication Service)와 같은 국제 표준 프로토콜에 적용하기 위한 연구가 필요하다.

• 한국컴퓨터정보학회논문지
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• 제16권7호
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• pp.85-93
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• 2011

본 논문은 지금까지 NP-완전인 난제로 알려진 정점 색칠 문제를 선형시간 복잡도로 해결한 알고리즘을 제안하였다. 제안된 알고리즘은 그래프 G=(V,E)의 최소 채색수 ${\chi}(G)$=k를 결정하기 위해 사전에 k값을 알지 못한다는 가정에 기반하고 있다. 단지 주어진 그래프를 독립집합 $\overline{C}$와 정점 피복 집합 C로 정확히 양분하여 $\overline{C}$에 색을 배정하는 방법을 적용하였다. 독립집합 $\overline{C}$의 원소는 ${\delta}(G)$인 정점 ${\upsilon}$가, C의 원소는 정점 ${\upsilon}$의 인접 정점들 u가배정된다. 축소된 그래프 C는 다시 $\overline{C}$와 C로 양분되며, 이 과정을 C의 간선이 없을 때까지 수행한다. 26개의 다양한 그래프를 대상으로 제안된 알고리즘을 적용한 결과 정점 ${\upsilon}$를 선택하는 횟수는 정점의 수 n보다 작은 값을 나타내었으며, ${\chi}(G)$=k를 찾는데 성공하였다.

• 동력기계공학회지
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• 제5권3호
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• pp.104-113
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• 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.

• 한국의류학회지
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• 제18권5호
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• pp.615-621
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• 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).

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1254-1263
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• 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.

• 한국식품조리과학회지
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• 제6권4호통권13호
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• pp.15-19
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• 1990

분질 감자인 남작, 중간질 감자인 세풍과 수미, 점질 감자인 대지마로부터 전분을 분리하여 가열 온도에 따른 호화도와 호화에 필요한 수분 함량을 조사하였다. 감자 전분 현탄액(5%)의 호화에 필요한 최저 온도는 $65^{\circ}C$이었다. $65^{\circ}C$에서의 호화도는 점질인 대지마 전분이 높고 분질인 남작 전분이 낮았으며 $75^{\circ}C$에서는 분질인 남작 전분이 가장 높고 중간질인 세풍 전분이 가장 낮게 나타났다. 감자 전분의 호화에 필요한 최저 수분 함량은 45%이었으며 $45{\sim}60%$에서의 전분의 호화도는 점질인 대지마 전분이 분질인 남작 전분보다 높았으나 70%에서는 모든 품종이 거의 비슷하였다.

• 한국표면공학회지
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• 제46권1호
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• pp.48-53
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• 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.

• Structural Engineering and Mechanics
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• 제85권3호
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• pp.407-417
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• 2023

Precast assembled bridge piers with hybrid connection (PASP) use both tendons and socket connections. To study the seismic performance of PASP, a full-scale in-situ test was performed based on an actual bridge project. The elastic-plastic fiber model of PASP was established using finite element software, and numerical analyses were performed to study the influence of prestress degree and socket depth on the PASP seismic performance. The results show that the typical failure mode of PASP under horizontal load is bending failure dominated by concrete cracking at the joint between the column and cushion cap. The cracking of the pier concrete and opening of joints depend on the prestress degree and socket depth. The prestressing tendons and socket connection can provide enough ductility, strength, restoration capability, and bending strength under small horizontal displacements. Although the bearing capacity and post yield stiffness of the pier can be improved to some extent by increasing the prestressing force, ductility is reduced, and residual deformation is increased. Overall, there are reasonable minimum socket depths to ensure the reliability of the socket connection.