Counting rooted unicursal planar maps

This paper investigates the number of rooted unicursal planar maps and presents some formulae for such maps with four parameters： the numbers of nonrooted vertices and inner faces and the valencies of two odd vertices.     

The number of rooted nearly cubicC-nets

This paper provides the parametric expressions satisfied by the enumerating functions for rooted nearly cubicc-nets with the size and/or the root-vertex valency of the maps as the parameters via nonseparable nearly cubic maps. On this basis, two explicit expressions of the functions can be derived by employing Lagrangian inversion. This Research is supported by National Natural Science Foundation of China (No. 19831080).     

Counting rooted near-4-regular Eulerian maps on some surfaces

In this article the rooted planar near-4-regular Eulerian trails are enumerated and an explicit formula for such maps is presented. Further, the rooted near-4-regular Eulerian maps on the torus are counted in an exact way.     

ENUMERATING ROOTED EULERIAN PLANAR MAPS

1 IntroductionSince Thtte's papers oll enunlerating planar InaPs in [7,8] published iu the beginlling Ofsixties, the enumerative theory has been developed greatly up to now. The enumeration ofgenera1 Eulerian planar maps is dependent on two paranleters as the valency of rooted vertexalld the uunther of edges Of the nmps. Y.P.Liu found tl1e functional equation firstly for thenlaPs aud then obtained the number of general rooted Elllerian planar maPs with the nuntherof edges given in 1989[1].…     

The number of rooted essential maps on surfaces

In this paper, general functional equations of rooted essential maps on surfaces （orientable and nonorientable） are deduced and their formal solutions are presented. Further, three explicit for- mulae for counting essential maps on S2,N3 andN4 are given. In the same time, some known results can be derived.     

Computing arbitrary Lagrangian Eulerian maps for evolving surfaces

The good mesh quality of a discretized closed evolving surface is often compromised during time evolution. In recent years this phenomenon has been theoretically addressed in a few ways, one of them uses arbitrary Lagrangian Eulerian (ALE) maps. However, the numerical computation of such maps still remained an unsolved problem in the literature. An approach, using differential algebraic problems, is proposed here to numerically compute an arbitrary Lagrangian Eulerian map, which preserves the mesh properties over time. The ALE velocity is obtained by finding an equilibrium of a simple spring system, based on the connectivity of the nodes in the mesh. We also consider the algorithmic question of constructing acute surface meshes. We present various numerical experiments illustrating the good properties of the obtained meshes and the low computational cost of the proposed approach.     

环面上有根欧拉地图的计数

本文探讨了环面上有限欧拉迹的计算并且提供了一个解析表达式．在此基础上，我们给出了环面上有根欧地图的计算公式．     

The number of rooted circuit boundary maps

In this article, the authors discuss two kinds of new planar maps： pan-fan maps and circuit boundary maps, and provide explicit expressions about their enumerating functions with different parameters. Meanwhile, two explicit counting formulas for circuit cubic boundary maps with two parameters; the size and the valency of the root-face, are also extracted.     

有根无环欧拉地图的数目

本文首先解决了有根无环欧拉地图依边数的三次计数方程的求解问题,同时提供一种有效的计数方法对先前的一些相关结果及其推导过程进行了必要的改进．     

Enumeration of multi-colored rooted maps

We present a study of n-colored rooted maps in orientable and locally orientable surfaces. As far as we know, no work on these maps has yet been published. We give a system of n functional equations satisfied by n-colored orientable rooted maps regardless of genus and with respect to edges and vertices. We exhibit the solution of this system as a vector where each component has a continued fraction form and we deduce a new equation generalizing the Dyck equation for rooted planar trees. Similar results are shown for n-colored rooted maps in locally orientable surfaces.     

环面上一般有根地图的计数

这篇文章给出了环面上以内面个数，根面次和非根节点个数为参数的一般有根地图的计数方程，导出了以内面个数和非根节点个数为参数的这类地图的计数方程的精确解。作为推论，推出了以边数为参数的这类地图的个数，其近似解在文献[2]中已讨论。     

Klein瓶上的奇异地图

It is well known that singular maps (i. e. ,those have only one face on a surface)play a key role in the theory of up-embeddability of graphs. In this paper the number of rooted singular maps on the Klein bottle is studied. An explicit form of the enumerating function according to the root-valency and the size of the map is determined. Further ,an expression of the vertex partition function is also found.     

Enumeration of rooted planar halin maps

A Halin map is a kind of planar maps oriented by a tree. In this paper the rooted halin maps with the vertex partition as parameters are enumerated such that a famous result on rooted trees due to Harary. Prins, and Tutte is deduced as. a special ease. Further, by using Lagrangian inversion to obtain a number of summation free formulae dixectly, the various kinds of rooted Halin maps with up to three parameters have been counted.     

Optimal estimation of Eulerian velocity field given Lagrangian observations

The problem of estimating an Eulerian velocity field given particle trajectories is formulated as an optimal filtering problem. Under the idealistic assumption that the Eulerian velocity field is delta-correlated in time (Kraichnan model) the exact solution of the non-linear filtering problem is found. In a more realistic Markov model with finite correlation time an approximate solution is suggested and examined by Monte Carlo means.     

The asymptotic number of rooted maps on a surface

Let S be a surface. We asymptotically enumerate two classes of n-edged maps on S as n → ∞: rooted and rooted smooth. These are based on a system of equations which give, in principle, the exact generating functions.     

The Enumeration of General Rooted Planar Maps

This paper provides some functional equations satisfied by the generating functions for enumerating general rooted planar maps with up to three parameters. Furthermore, the generating functions can be obtained explicitly by employing the Lagrangian inversion. This is also an answer to an open problem in 1989.     

Enumerating near-4-regular maps on the sphere and the torus

In this paper rooted near-4-regular maps on the plane and the torus are counted with formulae with respect to four parameters: the root valency, the number of edges, the inner faces, and nonroot-vertex loops. In particular, the number of rooted near-4-regular maps on those surfaces with exactly k nonroot-vertex loops is investigated.     

A census of boundary cubic rooted planar maps

In this paper, boundary cubic rooted planar maps are investigated and exact enumerative formulae are given. First, an enumerative formula for boundary cubic inner-forest maps with the size (number of edges) as a parameter is derived. For the special case of boundary cubic inner-tree maps, a simple formula with two parameters is presented. Further, according to the duality, a corresponding result for outer-planar maps is obtained. Finally, some results for boundary cubic planar maps and general planar maps are obtained. Furthermore, two known Tutte's formulae are easily deduced in the paper.     

Enumeration of maps on the projective plane

1. IntroductionA lnap is rooted if an edge is distinguished togetl1er with an end and a side of the edge.An edge belo11ging to only one face is called double (or 8ingular by some author), al1 othersbelonging to exactly two faces are called s1ngle. The enumeration of rooted p1anar maps wasfirst introduced by Tutte['], Techniques originated by Tutte [2,3l for enumerating variousclasses of rooted Inaps on tIle sphere are here applied to the c1asses of alI rooted maps onthe projective plane. Th…