نتایج جستجو برای: shannon index
تعداد نتایج: 404090 فیلتر نتایج به سال:
Selecting appropriate inputs for intelligent models is important due to reduce costs and save time and increase accuracy and efficiency of models. The purpose of this study is using Shannon entropy to select the optimum combination of input variables in time series modeling. Monthly time series of precipitation, temperature and radiation in the period of 1982-2010 was used from Tabriz synoptic ...
the aim of this study is comparison of soil characteristics and biodiversity in plantation of bald cypress and caucasian alder forest stands in kludeh region (mazandaran province). in order to study biodiversity in forest stands and control region, 10 sample plots (releve) were selected and the name and abundance of plant species of the forest floor were recorded. biodiversity of herbal plants ...
the distribution of macroinvertebrate communities from 5 sampling sites of the tajan river were used to examine the relationship among physiochemical parameters with macroinvertebrate communities and also to assess ecological classification system as a tool for the management and conservation purposes. the amount of variation explained in macroinvertebrate taxa composition is within values repo...
recognizing of genetic diversity and genetic potential of each plant species is necessary and essential before any works on breeding program. genetic diversity among five populations of walnut (juglans regia l.) was studied using 11 ssr markers. the marker system produced 77 alleles in a range size of 176-275 bps. the minimum (2) and maximum (11) numbers of alleles were related to genetic locus...
in order to investigate the effects of soil chemical characteristics on weed species diversity in eastern mashhad region wheat (triticum aestivum l.) fields, an investigation was held in the year 2009. wheat fields were classified based on the acreage from 3-5, 5-10 and higher than 10 ha. five random soil samples were taken using a 5 cm diameter auger from the soil of each experimental field an...
ground beetles (family carabidae) with more than 40,000 described species worldwide are one of the most important generalist predators in agroecosystems. because of their habit of feeding on agricultural pests and weed seeds, in this study we tried to assess their biodiversity in agroecosystems of azadshahr region, eastern golestan province. samples were collected for some main crops, using pit...
A noiseless multiple-input multiple-output (MIMO) channel operating under a strict complexity constraint at the receiver is introduced. According to this constraint, detected bits, obtained by performing hard decisions directly on the channel’s matched filter output, must be the same as the transmitted binary inputs. An asymptotic analysis is carried out using mathematical tools originated from...
The stocks and characteristics of coarse woody debris (CWD) are expected to reflect forest stand features. However, despite their importance, there have been no reports of CWD stocks and characteristics in the Qinling Mountains. We measured the CWD stocks in different CWD types, decay classes and diameter classes of the five forest types in the Qinling Mountains. The highest biomass of CWD was ...
The Boltzmann–Gibbs and Tsallis entropies are essential concepts in statistical physics, which have found multiple applications in many engineering and science areas. In particular, we focus our interest on their applications to image processing through information theory. We present in this article a novel numeric method to calculate the Tsallis entropic index q characteristic to a given image...
Forests are biologically diverse systems, representing some of the richest biological areas on Earth. They offer a variety of habitats for plants, animals and micro-organisms. However, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. Biodiversity is the variation of life forms within a given ecosystem, biome, or on t...
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