Trees have played a key role in the study of constraint satisfaction problems because problems with tree structure can be solved efficiently. It is shown here that a family of generalized trees, k-trees, can offer increasing representational complexity for constraint satisfaction problems, while maintaining a bound on computational complexity linear in the number of variables and exponential in...

In this work we provide a combinatorial analysis of bucket recursive trees, which have been introduced previously as a natural generalization of the growth model of recursive trees. Our analysis is based on the description of bucket recursive trees as a special instance of so called bucket increasing trees, which is a family of combinatorial objects introduced in this paper. Using this combinat...

in this paper, using generalized {polya} urn models we find the expected value of the size of a branch in recursive $k$-ary trees. we also find the expectation of the number of nodes of a given outdegree in a branch of such trees.

Agroforestry is a dynamic, ecologically based, natural resource management system that, through the integration of trees in farm and rangeland, diversifies and sustains production for increased social, economic and environmental benefits (Leakey, 1996). Apart from the social and cultural advantages of growing trees, recreational benefits for human being, as well as improvement in wildlife, ther...

A purpose of Zagros forests preservation plan is to reduce degradation factors through empowering woodman beneficiaries and underdevelopment of rural forested areas which appear as scattered agronomies inside and in forest margins, trees cutting for power supply, trees cutting for hay supply or making coal in forested regions. Therefore, natural resources experts believe that, by creation or im...

ABSTRACT. In this work we provide a combinatorial analysis of bucket recursive trees, which have been introduced previously as a natural generalization of the growth model of recursive trees. Our analysis is based on the description of bucket recursive trees as a special instance of so called bucket increasing trees, which is a family of combinatorial objects introduced in this paper. Using thi...