quantifying spatial structure is one of the most important components, describing natural ecosystems and their biodiversity. in this study, a set of indices and functions related to spatial structure using 102 established plots with an area of 1000 m2 were presented. to achieve spatial structure of carpinus-fagus type, a set of indices (clark & evans, uniform angle, shannon-wiener, mingling and...

The main idea of graph based image modeling is that the regions of the image, which contain similar properties, are denoted by graph vertices, and the relations between different regions are denoted by graph edges. The vertex and edge attributes usually describe the characteristics of that region and the relation between regions respectively. A simple approach to keep the structural and topolog...

in this paper‎, ‎we consider the following kirchhoff-type equations‎: ‎$-‎left(a+bint_{mathbb{r}^{3}}|nabla u|^{2}right)delta u+v(x) u=lambda$ $f(x,u)+u^{5}‎, ‎quad mbox{in }mathbb{r}^{3},$ ‎$u(x)>0‎, ‎quad mbox{in }mathbb{r}^{3},$ ‎$uin h^{1}(mathbb{r}^{3})‎ ,‎$ ‎ ‎‎‎where $a,b>0$ are constants and $lambda$ is a positive parameter‎. ‎the aim of this paper is to study the existence of positive ...

In this paper, two compact quad-channel and six-channel diplexer are designed and fabricated using defected microstrip structure (DMS). This structure is designed for the desired frequency based on the literature reviews. The proposed configuration is composed of a conventional T-junction divider with two pairs of open bended stubs and dual/tri-band filters. In designing dual band filters, a lo...

An algorithm is described for transforming a quad tree encoding for a picture into a quad tree for the same picture after application of a general linear operator. The technique relies on algorithms and data structures described previously for the construction and superposition of quad trees. The transformation algorithm is shown to take time O(n + sp + mp), where n is the number of nodes in th...

Let $x$ and $y$ be two distinct vertices in a connected graph $G$. The $x,y$-location of a vertex $w$ is the ordered pair of distances from $w$ to $x$ and $y$, that is, the ordered pair $(d(x,w), d(y,w))$. A set of vertices $W$ in $G$ is $x,y$-located if any two vertices in $W$ have distinct $x,y$-location.A set $W$ of vertices in $G$ is 2-located if it is $x,y$-located, for some distinct...

The paper extends the recently published methods for image reconstruction and texture minification using the generalized ripmap method, named fipmap, and quad-trees. Fipmap is based on the technique of partitioned iterated function systems, used in fractal image compression. The quad-tree texture reconstruction algorithm works well for many standard cases. The special cases can be solved using ...