Let G be a simple graph of order n and girth g. For any two adjacent vertices u and v of G, if d G (u) + d G (v) ? n ? 2g + 5 then G is up-embeddable. In the case of 2-edge-connected (resp. 3-edge-connected) graph, G ...Let G be a simple graph of order n and girth g. For any two adjacent vertices u and v of G, if d G (u) + d G (v) ? n ? 2g + 5 then G is up-embeddable. In the case of 2-edge-connected (resp. 3-edge-connected) graph, G is up-embeddable if d G (u) + d G (v) ? n ? 2g + 3 (resp. d G (u) + d G (v) ? n ? 2g ?5) for any two adjacent vertices u and v of G. Furthermore, the above three lower bounds are all shown to be tight.展开更多
This paper concerns with two reasons for stock price fluctuation, the instinctive stochastic fluctuation and the fluctuation caused by the spread of information. They are constructed by compound Poisson process and co...This paper concerns with two reasons for stock price fluctuation, the instinctive stochastic fluctuation and the fluctuation caused by the spread of information. They are constructed by compound Poisson process and continuum percolation model separately. Combining the two models, the authors get a Levy process for the price fluctuation that can explain the fat-tail phenomenon in stock market. The fat-tails axe also presented in numerical simulations.展开更多
In this paper we mainly prove that let G be a(k+1)-edge-connected simple graph of order n with girth g.Then G is upper embeddable if for any independent set I(G) = {vi | 1 i k2 + 2},k = 0,1,2 and the lower bound is ti...In this paper we mainly prove that let G be a(k+1)-edge-connected simple graph of order n with girth g.Then G is upper embeddable if for any independent set I(G) = {vi | 1 i k2 + 2},k = 0,1,2 and the lower bound is tight.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 10571013)
文摘Let G be a simple graph of order n and girth g. For any two adjacent vertices u and v of G, if d G (u) + d G (v) ? n ? 2g + 5 then G is up-embeddable. In the case of 2-edge-connected (resp. 3-edge-connected) graph, G is up-embeddable if d G (u) + d G (v) ? n ? 2g + 3 (resp. d G (u) + d G (v) ? n ? 2g ?5) for any two adjacent vertices u and v of G. Furthermore, the above three lower bounds are all shown to be tight.
基金supported by the Natural Science Foundation of Tianjin,China under Grant No.09JCYBLJC01800the China Postdoctoral Science Foundation Funded Project under Grant No.20110491248
文摘This paper concerns with two reasons for stock price fluctuation, the instinctive stochastic fluctuation and the fluctuation caused by the spread of information. They are constructed by compound Poisson process and continuum percolation model separately. Combining the two models, the authors get a Levy process for the price fluctuation that can explain the fat-tail phenomenon in stock market. The fat-tails axe also presented in numerical simulations.
文摘In this paper we mainly prove that let G be a(k+1)-edge-connected simple graph of order n with girth g.Then G is upper embeddable if for any independent set I(G) = {vi | 1 i k2 + 2},k = 0,1,2 and the lower bound is tight.
