广西科学
廣西科學
엄서과학
GUANGXI SCIENCES
2014年
3期
287-289
,共3页
色数%Kneser图%平方图
色數%Kneser圖%平方圖
색수%Kneser도%평방도
chromatic number%Kneser graph%square graph
Kneser图KG(n,k)的顶点集包括一个n元集的所有k元子集,其中的任意两个顶点相邻当且仅当它们对应的子集不相交.一个图G的平方图G 2的顶点集与G的顶点集相同,在G2中两个顶点之间有边当且仅当它们在G中的距离不超过2.通过理论分析和计算机搜索,得到8≤χ(KG2(11,5))≤10,10≤χ(KG2(13,6))≤16,其中前一个结论改进了已知的下界7和上界12.
Kneser圖KG(n,k)的頂點集包括一箇n元集的所有k元子集,其中的任意兩箇頂點相鄰噹且僅噹它們對應的子集不相交.一箇圖G的平方圖G 2的頂點集與G的頂點集相同,在G2中兩箇頂點之間有邊噹且僅噹它們在G中的距離不超過2.通過理論分析和計算機搜索,得到8≤χ(KG2(11,5))≤10,10≤χ(KG2(13,6))≤16,其中前一箇結論改進瞭已知的下界7和上界12.
Kneser도KG(n,k)적정점집포괄일개n원집적소유k원자집,기중적임의량개정점상린당차부당타문대응적자집불상교.일개도G적평방도G 2적정점집여G적정점집상동,재G2중량개정점지간유변당차부당타문재G중적거리불초과2.통과이론분석화계산궤수색,득도8≤χ(KG2(11,5))≤10,10≤χ(KG2(13,6))≤16,기중전일개결론개진료이지적하계7화상계12.
The Kneser graph KG(n,k)is the graph whose vertex set consists of all k-subsets of an n-set,and two vertices are adj acent if and only if they are disj oint.The square G2 of a graph G is defined on the vertex set of G such that distinct vertices within distancetwo in G are j oined by an edge.By theoretical analysis and computer search,we obtain that 8 ≤χ(KG2(11,5))≤10,which improves the known lower bound 7 and upper bound 12,and that 10 ≤χ(KG2(13, 6))≤ 16.