EDGE-FACE CHROMATIC NUMBER OF 2-CONNECTED PLANE GRAPHS WITH HIGH MAXIMUM DEGREE

The edge-face chromatic number Xef （G） of a plane graph G is the least number of colors assigned to the edges and faces such that every adjacent or incident pair of them receives different colors. In this article, the authors prove that every 2-connected plane graph G with △（G）≥｜G｜ - 2≥9 has Xef（G） = △（G）.

A SEVEN-COLOR THEOREM ON EDGE-FACE COLORING OF PLANE GRAPHS

Melnikov(1975) conjectured that the edges and faces of a plane graph G can be colored with △(G) + 3 colors so that any two adjacent or incident elements receive distinct colors, where △(G) denotes the maximum degree of G. This paper proves the conjecture for the case △(G) ≤4.

(3, 1)^(*)-choosability of plane graphs without adjacent single cycles

Given a list assignment of L to graph G,assign a list L(υ)of colors to each υ∈V(G).An(L,d)^(*)-coloring is a mapping π that assigns a color π(υ)∈L(υ)to each vertex υ∈V(G)such that at most d neighbors of υ receive the color υ.If there exists an(L,d)^(*)-coloring for every list assignment L with|L(υ)|≥k for all υ∈ V(G),then G is called to be(k,d)^(*)-choosable.In this paper,we prove every planar graph G without adjacent k-cycles is(3,1)^(*)-choosable,where k ∈{3,4,5}.

On the Adjacent Strong Edge Coloring of Outer Plane Graphs

A k-adjacent strong edge coloring of graph G(V, E) is defined as a proper k-edge coloring f of graph G(V, E) such that f[u] ≠ f[v] for every uv ∈ E(G), where f[u] = {f(uw)|uw ∈ E(G)} and f(uw) denotes the color of uw, and the adjacent strong edge chromatic number is defined as x'as(G) = min{k| there is a k-adjacent strong edge coloring of G}. In this paper, it has been proved that △ ≤ x'as(G) ≤ △ + 1 for outer plane graphs with △(G) ≥ 5, and X'as(G) = △ + 1 if and only if there exist adjacent vertices with maximum degree.

Labelings of Plane Graphs Containing Hamilton Path

This paper deals with the problem of labeling the vertices, edges and faces of a plane graph. A weight of a face is the sum of the label of a face and the labels of the vertices and edges surrounding that face. In a super d-antimagic labeling the vertices receive the smallest labels and the weights of all s-sided faces constitute an arithmetic progression of difference d, for each s appearing in the graph. The paper examines the existence of such labelings for plane graphs containing a special Hamilton path.

Super d-antimagic Labelings of Disconnected Plane Graphs

This paper deals with the problem of labeling the vertices, edges and faces of a plane graph in such a way that the label of a face and the labels of the vertices and edges surrounding that face add up to a weight of that face, and the weights of all s-sided faces constitute an arithmetic progression of difference d, for each s that appears in the graph. The paper examines the existence of such labelings for disjoint union of plane graphs.

On 3-colorings of Plane Graphs

In this paper, we prove that if G is a plane graph without 4-, 5- and 7-circuits and without intersecting triangles, then for each face f of degree at most 11, any 3-coloring of the boundary of f can be extended to G. This gives a positive support to a conjecture of Borodin and Raspaud which claims that each plane graph without 5-circuits and intersecting triangles is 3-colorable.

A 3-color Theorem on Plane Graphs without 5-circuits

In this paper, we prove that every plane graph without 5-circuits and without triangles of distance less than 3 is 3-colorable. This improves the main result of Borodin and Raspaud [Borodin, O. V., Raspaud, A.： A sufficient condition for planar graphs to be 3-colorable. Journal of Combinatorial Theory, Ser. B, 88, 17-27 （2003）], and provides a new upper bound to their conjecture.

On 3-choosability of triangle-free plane graphs

It is known that every triangle-free plane graph is 3-colorable.However,such a triangle-free plane graph may not be 3-choosable.In this paper,we prove that a triangle-free plane graph is 3-choosable if no 4-cycle in it is adjacent to a 4-or a 5-cycle.This improves some known results in this direction.

A Sufficient Condition on 3-colorable Plane Graphs Without 5- and 6-circuits

In 2003, Borodin and Raspaud proved that if G is a plane graph without 5-circuits and without triangles of distance less than four, then G is 3-colorable. In this paper, we prove that if G is a plane graph without 5- and 6-circuits and without triangles of distance less than 2, then G is 3-colorable.

ON 3-CHOOSABIL ITY OF PL ANE GRAPHSON3 -CHOOSABIL ITY OF PL ANE GRAPHS WITHOUT 6-,7-AND 9-CYCLES

The choice number of a graph G,denoted byχl(G) ,is the minimum number k such that if a list of k colors is given to each vertex of G,there is a vertex coloring of G where each vertex receives a color from its own listno matter whatthe lists are.In this paper,itis showed thatχl(G)≤ 3 for each plane graph of girth not less than 4 which contains no 6- ,7- and 9- cycles

AN SIRS EPIDEMIC MODEL

This paper considers an SIRS epidemic model that incorporates constant immigrati on rate, a general population size dependent contact rate and proportional tran sfer rate from the infective class to susceptible class.A threshold parameter σ is identified. If σ≤1, the disease free equilibrium is globally stab le. If σ>1, a unique endemic equilibrium is locally asymptotically stable. For two important special cases of mass action incidence and standard incidence, global stability of the endemic equilibrium is proved provided the threshold is larger than unity. Some previous results are extended and improved.

Application of CorelDRAW in Environmental Art Design

CorelDRAW has particular uses in architectural design, interior design and landscape design. By comparing several software, it was found that CorelDRAW had the working plan drawing of AutoCAD, mapping of 3DMAX, and better typesetting than Photoshop had, thus it plays an irreplaceable role in drawing working plan of environmental art design, especially colored plane and elevation view drawings.

Embedding generalized of circulant graphs and Petersen graphs on projective plane

Both the circulant graph and the generalized Petersen graph are important types of graphs in graph theory. In this paper, the structures of embeddings of circulant graph C（2n ＋ 1; {1, n}） on the projective plane are described, the number of embeddings of C（2n ＋ 1; {1, n}） on the projective plane follows, then the number of embeddings of the generalized Petersen graph P（2n ＋ 1, n） on the projective plane is deduced from that of C（2n ＋ 1; {1, n}）, because C（2n ＋ 1; {1, n}） is a minor of P（2n ＋ 1, n）, their structures of embeddings have relations. In the same way, the number of embeddings of the generalized Petersen graph P（2n, 2） on the projective plane is also obtained.

The acyclic chromatic index of planar graphs without 4-,6-cycles and intersecting triangles

A proper edge k-coloring is a mappingΦ:E(G)-→{1,2,...,k}such that any two adjacent edges receive different colors.A proper edge k-coloringΦof G is called acyclic if there are no bichromatic cycles in G.The acyclic chromatic index of G,denoted by Xa(G),is the smallest integer k such that G is acyclically edge k-colorable.In this paper,we show that if G is a plane graph without 4-,6-cycles and intersecting 3-cycles,△(G)≥9,then Xa(G)≤△(G)+1.

The Number of Circles of a Maximum State of a Plane Graph with Applications

Motivated by the connection with the genus of the corresponding link and its application on DNA polyhedral links,in this paper,we introduce a parameter s_(max)(G),which is the maximum number of circles of states of the link diagram D(G)corresponding to a plane(positive)graph G.We show that s_(max)(G)does not depend on the embedding of G and if G is a 4-edge-connected plane graph then s_(max)(G)is equal to the number of faces of G,which cover the results of S.Y.Liu and H.P.Zhang as special cases.

Central Circuit Coverings of Octahedrites and Medial Polyhedra

An octahedrite is a 4-valent polyhedron with only 3-faces and 4-faces. We study edge-partitions of some octahedrites, medial and related polyhedra into central circuits.