A non-decreasing sequence of positive integer weights P = {p1, . . . , p2, pn} is called k-ordered if an intermediate sequence of weights produced by Huffman algorithm for initial sequence P on i-th step satisfies the following conditions: p (i) 2 = p (i) 3 , i = 0, k; p (i) 2 < p (i) 3 , i = k + 1, n − 3. Let T be a binary tree of size n and M = M(T ) be a set of such sequences of positive int...

It has been shown that height measurements obtained by airborne laser scanning (ALS) with high point density (>7–8 m ́2) can be used to detect small trees in the alpine tree line—an ecotone sensitive to climate change. Because the height measurements do not discriminate between trees and other convex structures with positive height values, this study aimed at assessing the contribution of ALS ba...

We investigated community structure and tree species diversity of six subtropical mountain forests in relation to 11 topographical and edaphic factors in Lower Lancang River Basin, Yunnan Province, China, based on a census of all trees with diameter at breast height≥5 cm in 45 0.06-ha plots. The forests were as follows: a river valley monsoon forest, semi-humid evergreen broad-leaved forest, mo...

It is well-known that any chordal graph can be represented as a clique tree (acyclic hypergraph, join tree). Since some chordal graphs have many distinct clique tree representations, it is interesting to consider which one is most desirable under various circumstances. A clique tree of minimum diameter (or height) is sometimes a natural candidate when choosing clique trees to be processed in a ...

The coalescent with recombination is a fundamental model to describe the genealogical history of DNA sequence samples from recombining organisms. Considering recombination as a process which acts along genomes and which creates sequence segments with shared ancestry, we study the influence of single recombination events upon tree characteristics of the coalescent. We focus on properties such as...

It is well-known that any chordal graph can be represented as a clique tree (acyclic hypergraph, join tree). Since some chordal graphs have many distinct clique tree representations, it is interesting to consider which one is most desirable under various circumstances. A clique tree of minimum diameter (or height) is sometimes a natural candidate when choosing clique trees to be processed in a ...

Remote-sensing (RS) methods, such as airborne laser scanning (ALS), are capable of acquiring tree-level forest information with high accuracy. However, these methods need more detailed reference data from sample plots than standwise mean characteristics. Field-measured treewise characteristics must be matched with ALS data on the measured position of the tree. In addition to tree position and s...

A non-decreasing sequence of positive integer weights P ={p1, p2,..., pn} (n = N*(m-1) + 1, N is number of non-leaves of m-ary tree) is called absolutely ordered if the intermediate sequences of weights produced by m-ary Huffman algorithm for initial sequence P on i-th step satisfy the following conditions 2 , , ) ( 1 ) ( − = < + N 0 i p p i m i m . Let T be an m-ary tree of size n and M=M(T) b...

The behaviour of a greedy algorithm which estimates the height of a random labelled rooted tree is studied. A self-similarity argument is used to characterize the limit distribution of the length H of the path found by such an algorithm in a random rooted tree as the unique solution of an integral equation. Furthermore, it is shown that lim n!1 E H p n = p 2 2 p 2 ln(3 + 2 p 2) = 2 : 353139::: ...

the oriental beech constitute one third of northern forests area and stocking volume in the north ofiran. these stands obseve in pure and mixed. in order to properly management which guaranteesustained yield, it is crucial to collect basic information including stocking (volume and stem number),tree growth, diameter distribution pattern, diameter-height relationship, diameter-volume relationshi...