نتایج جستجو برای: tree height

تعداد نتایج: 265995  

2015
Yan-qiong Li Xiang-wen Deng Zhi-hong Huang Wen-hua Xiang Wen-de Yan Pi-feng Lei Xiao-lu Zhou Chang-hui Peng

Tree diameter at breast height (dbh) and height are the most important variables used in forest inventory and management as well as forest carbon-stock estimation. In order to identify the key stand variables that influence the tree height-dbh relationship and to develop and validate a suit of models for predicting tree height, data from 5961 tree samples aged from 6 years to 53 years and colle...

Kargar, Mohammad Reza , Sohrabi, Hormoz,

Two-dimensional image conversion algorithms to 3D data create the hope that the structural properties of trees can be extracted through these images. In this study, the accuracy of biomass estimation in tree, plot, and hybrid levels using UAVs images was investigated. In 34.8 ha of Sisangan Forest Park, using a quadcopter, 854 images from an altitude of 100 meters above ground were acquired. SF...

2004
Xiaowei Yu Juha Hyyppä Hannu Hyyppä Matti Maltamo

High-density airborne laser scanner data has been previously shown to provide great opportunities for individual tree detection and measurement of variables characterizing the detected trees. This paper evaluates the effect of laser flight altitude on the tree height estimation at individual tree level in the boreal forest area mainly consisting of Norway spruce, Scots pine and birch. The test ...

2009
Mohd Mahmood Ali Lakshmi Rajamani

Classification is considered as one of the building blocks in data mining problem and the major issues concerning data mining in large databases are efficiency and scalability. In this paper we propose a data classification method using AVL trees enhances the quality and stability of data mining problems. Researchers from various disciplines such as statistics, machine learning, pattern recogni...

2016
Petras Rupšys

The aim of this paper is twofold: to introduce the mathematics of stochastic differential equations (SDEs) for forest dynamics modeling and to describe how such a model can be applied to aid our understanding of tree height distribution corresponding to a given diameter using the large dataset provided by the Lithuanian National Forest Inventory (LNFI). Tree height-diameter dynamics was examine...

2007
Jaan Praks Florian Kugler Konstantinos Papathanassiou Martti Hallikainen

In this paper we present a airborne polarimetric interferometric SAR measurement campaign, carried out in Finland in 2003. The main aim of the FinSAR campaign was to validate POLinSAR tree height retrieval algorithms for boreal forest and it was arranged jointly by Helsinki University of Technology (TKK) and German Aerospace Center (DLR) Microwaves and Radar Institute. During the campaign airbo...

2017
Ville Luoma Ninni Saarinen Michael A. Wulder Joanne C. White Mikko Vastaranta Markus Holopainen Juha Hyyppä

Forest resource information has a hierarchical structure: individual tree attributes are summed at the plot level and then in turn, plot-level estimates are used to derive stand or large-area estimates of forest resources. Due to this hierarchy, it is imperative that individual tree attributes are measured with accuracy and precision. With the widespread use of different measurement tools, it i...

2002
Arnold Beckmann

Height restricted resolution (proofs or refutations) is a natural restriction of resolution where the height of the corresponding proof tree is bounded. Height restricted resolution does not distinguish between treeand sequence-like proofs. We show that polylogarithmic-height resolution is strongly connected to the bounded arithmetic theory S 2(α). We separate polylogarithmic-height resolution ...

Journal: :Inf. Process. Lett. 1988
Sakti Pramanik Myoung-Ho Kim

B-tree type indexes are popular in database applications because they provide a fast access path to large databases. In this paper we present a new storage structure which is suitable for fast parallel searching by using B-tree like indexes [I]. We call this modified B_ tree structure the Height Compressed B_ tree (HCB_tree). The main results presented in this paper are that parallel processing...

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