The Ideal Free Distribution theory predicts a close spatial match between predators and prey. Studies have shown that seabird and prey distribution seldom conforms with this prediction. In this study, I review recent theoretical advances in spatial predator–prey interactions and relate these with studies of seabirds and pelagic schooling fish and crustaceans. Studies on seabirds and prey have g...

The Weibull distribution is widely employed in several areas of engineering because it is an extremely flexible distribution with different shapes. Moreover, it can include characteristics of several other distributions. However, successful usage of Weibull distribution depends on estimation accuracy for three parameters of scale, shape and location. This issue shifts the attentions to the requ...

a field experiment was conducted to study the spatial relationships between weed seed bank and population and their distribution models in sugar beet crop (beta vulgaris) in 2009 at motahari  agricultural research station of karaj. sampling from seed bank before sugar beet drilling and weed population in three stages during the growing season were done using square (50*50 cm) and rectangle (25*...

Cuckoo algorithm is a novel optimization algorithm in the field of heuristic intelligence algorithms. Given the strong random leaping in solution space search, careful local searches are susceptible to falling into the local optimum. Thus, the latter phase of the optimization slows down and the accuracy diminishes. To improve the performance of the algorithm, this paper proposes an improved cuc...

Functional and structural changes of regional system are ongoing spatial changes that form patterns of spatial organization, depending on dominant regional forces and factors. Spatial structure of West Azerbaijan province experienced significant changes during 15 years; thus, the present research aim to investigate the manner of spatial distribution of two variables of population and activity, ...

spatial distribution of thermal regions is dependent on local factors and circulation patterns in long terms. recognition of spatial distribution of temperature in geographical regions could be help on planning and environmental policies. the aim of this paper is recognition and detachment of thermal regions in iran. for this object, maximum daily temperature data have been provided using 620 s...

In this work, a new hybrid Symbiotic Organisms Search (SOS) algorithm introduced to design and optimize spatial and planar structures under structural constraints. The SOS algorithm is inspired by the interactive behavior between organisms to propagate in nature. But one of the disadvantages of the SOS algorithm is that due to its vast search space and a large number of organisms, it may trap i...