Vertex-distinguishing IE-total Colorings of Cycles and Wheels

Let G be a simple graph. An IE-total coloring f of G refers to a coloring of the vertices and edges of G so that no two adjacent vertices receive the same color. Let C（u） be the set of colors of vertex u and edges incident to u under f. For an IE-total coloring f of G using k colors, if C（u）=C（v） for any two different vertices u and v of V （G）, then f is called a k-vertex-distinguishing IE-total-coloring of G, or a k-VDIET coloring of G for short. The minimum number of colors required for a VDIET coloring of G is denoted by χievt（G）, and is called the VDIET chromatic number of G. We get the VDIET chromatic numbers of cycles and wheels, and propose related conjectures in this paper.     

Sub-exponential graph coloring algorithm for stencil-based Jacobian computations

Partial differential equations can be discretized using a regular Cartesian grid and a stencil-based method to approximate the partial derivatives. The computational effort for determining the associated Jacobian matrix can be reduced. This reduction can be modeled as a (grid) coloring problem. Currently, this problem is solved by using a heuristic approach for general graphs or by developing a formula for every single stencil. We introduce a sub-exponential algorithm using the Lipton–Tarjan separator in a divide-and-conquer approach to compute an optimal coloring. The practical relevance of the algorithm is evaluated when compared with an exponential algorithm and a greedy heuristic.     

若干冠图的邻点可区别V-全染色

应用构造染色函数法研究了冠图C_m·C_n、C_m·C_n的邻点可区别V-全染色.通过对P_m·C_n的邻点可区别V-全染色的研究巧妙给出了C_m·C_n邻点可区别V-全染色,并得到了这些图的邻点可区别V-全色数,从而验证了图的邻点可区别V-全染色猜想.     

Acyclic edge coloring of triangle-free 1-planar graphs

A proper edge coloring of a graph G is acyclic if there is no 2-colored cycle in G. The acyclic chromatic index of G, denoted by χ a(G), is the least number of colors such that G has an acyclic edge coloring. A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this paper, it is proved that χ a(G) ≤Δ(G) + 22, if G is a triangle-free 1-planar graph.     

Monochromatic sinks in nearly transitive arc-colored tournaments

Let T be the set of all arc-colored tournaments, with any number of colors, that contain no rainbow 3-cycles, i.e., no 3-cycles whose three arcs are colored with three distinct colors. We prove that if T∈T and if each strong component of T is a single vertex or isomorphic to an upset tournament, then T contains a monochromatic sink. We also prove that if T∈T and T contains a vertex x such that T−x is transitive, then T contains a monochromatic sink. The latter result is best possible in the sense that, for each n≥5, there exists an n-tournament T such that (T−x)−y is transitive for some two distinct vertices x and y in T, and T can be arc-colored with five colors such that T∈T, but T contains no monochromatic sink.     

五像限法太阳自动跟踪仪

介绍由两心圆组成的等面积五像限光测量装置工作原理，即当光线与光电池垂直时其投影光斑经过一透镜后正好安全覆盖五片光电池，当光线与光电池成一夹角时，其投影光斑必然发生偏移，将光主在光电池上的偏移转移成光电流差值的变化，实现装置自动跟踪太阳。     

On the geometry of the Batalin–Vilkovisky formalism

In this work it is proved that the geometry of the well-known quantization scheme of general gauge theories, the so-called Batalin–Vilkovisky formalism, is the odd Riemannian geometry. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 28–31, November, 2008.     

联系数中差异度系数i的专家估测法及应用

在联系数中差异度系数i已有取值方法的基础上,给出了差异度系数i的专家估测取值方法、加权统计取值方法和频数统计取值方法以及它们在实际中的应用.