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...

in this study, the spatial distribution of overwintered adults of sunn pest, eurygaster integriceps puton, was investigated by using dispersion parameters and indices, mathematical distribution, and regression techniques in rainfed wheat fields by sample size of 1 m2 in 2009 and 2010. the dispersion parameters including: mean-variance test and clumping parameter () showed that the overwintered ...

analysis of the spatial and temporal trends of precipitation and temperature are pertinent for future development and sustainable management of water resources in a given region. in this paper, we present a study concerning the climatic behavior of two principal observables variables, viz. monthly temperature (maximum and minimum) and mean precipitations obtained from the measurements carried o...

seasonal activity and spatial distribution of eoteranychus frosti mcgregor, tydeus longisetosus (elbagouy and momen) and zetzellia mali ewing were studied during 9th july to 22th october 2006 in an unsprayed apple orchard, maragheh region, northwest of iran. also the density dependence interaction between preys and predator was assessed. to estimate the spatial distribution pattern of these spe...

the population densities and spatial distribution patterns of zetzellia pourmirzai khanjani and ueckermann and its preys cenopalpus irani dosse and bryobia rubrioculus (scheuten) were studied in a sprayed orchard in kermanshah, a western province of iran, from 31 may till 7 november, 2007. the interaction (density dependence) between the plant feeding mites and their predator was determined as ...

abstract recent interest in describing the spatial distribution patterns of weeds through using interpolation methods has increased to estimate weed seedling density from spatially refferenced data and evaluation of applicable to site-specific weed management. in this research, a multi layer perceptron neural network (mlpnn) model was developed to predict the spatial distribution of h. glaucum ...

Researchers have identified numerous factors that impact the diffusion of open source software (OSS). This paper proposes an integrated model that studies how key factors affect the diffusion dynamics of OSS. Specifically, we investigate the role of software upgrade cycle in the diffusion of OSS. We also incorporate factors such as variability in OSS support costs, interoperability issues and n...

introduction: cost estimation is a important tool which assist the managers to plan and to control the economic functions of the organization. the present study aims to identify the cost of a cesarean surgery in one of the first class public hospitals in iran. methodology: reviewing all expenses of the hospital documents in the financial unit, the cost of a cesarean surgery was determined throu...

In this paper, we propose an analytical and methodological comparison between two of the most known distance-based methods in the evaluation of the geographic concentration of economic activity. These two methods are Ripley’s K function, a cumulative function popularised by Marcon and Puech (2003) that counts the average number of neighbours of each point within a circle of a given radius, and ...