نتایج جستجو برای: density distribution

تعداد نتایج: 974041  

ژورنال: فیزیک زمین و فضا 2014
M Ashtari Jafari S Vatankhah V Ardestani, E.

Applying 2D algorithms for inverting the potential field data is more useful and efficient than their 3D counterparts, whenever the geologic situation permits. This is because the computation time is less and modeling the subsurface is easier. In this paper we present a 2D inversion algorithm for interpreting gravity data by employing a set of constraints including minimum distance, smoothness,...

    Sampling methods have a theoretical basis and should be operational in different forests; therefore selecting an appropriate sampling method is effective for accurate estimation of forest characteristics. The purpose of this study was to estimate the stand density (number per hectare) in Arasbaran forest using a variety of the plotless density estimators of the nearest neighbors sampling me...

Journal: :تحقیقات اقتصادی 0
محمد سخنور دانشجوی دکترای علوم اقتصادی دانشگاه تربیت مدرس حسین صادقی استادیار دانشگاه تربیت مدرس عباس عصاری استادیار دانشگاه تربیت مدرس کاظم یاوری دانشیار دانشگاه تربیت مدرس الیاس نادران دانشیار دانشگاه بوعلی سینا همدان

in this article, we have used 36 electricity distribution companies of iran and by using input-oriented dea, we analysis the companies technical efficiency with respect to group frontier and metafrontier following restructuring, then we investigate the factors affecting efficiency. the companies decomposed to two groups in terms of high and low circuit density. for discussing the impact of stru...

Journal: :تحقیقات دامپزشکی 0
عباس ایمانی باران گروه پاتوبیولوژی، دانشکده دامپزشکی دانشگاه تبریز، تبریز- ایران محمد یخچالی گروه پاتوبیولوژی، دانشکده دامپزشکی دانشگاه ارومیه ، ارومیه- ایران رضا ملک زاده ویایه پژوهشکده آرتمیا و جانوراد آبزی دانشگاه ارومیه، ارومیه- ایران بهارک صحت نیا پژوهشکده آرتمیا و جانوراد آبزی دانشگاه ارومیه، ارومیه- ایران رضا درویش زاده گروه زراعت و اصلاح نباتات، دانشکده کشاورزی دانشگاه ارومیه، ارومیه- ایران

background: freshwater pulmonate family lymnaeidae are well-known for their role in transmission of diginean trematodes worldwide. objectives: the study was aimed to investigate the ecology and effects of physical and chemical components of the environment on their distribution and populaion density. methods: the lymnaeid snails were randomly collected from 16 freshwater habitats in west azarba...

Journal: :محیط شناسی 0
آرش کرمی کارشناسی ارشد جنگلداری و اقتصادجنگل دانشکدة منابع طبیعی، دانشگاه تهران جهانگیر فقهی دانشیارگروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی، دانشگاه تهران

nowadays, with the development of human societies and more mastery over the environment, to environmental changes caused by the faster and wider than before the occurrence of the joins. so having the necessary information about these changes and to manage the natural order is essential to sustainable ecosystems, metrics of landscape is tools landscape situation are few mechanisms that cause the...

In this paper, a new generalization of the half-normal distribution which is called the perturbed half-normal distribution is introduced. The new distribution belongs to a family of distributions which includes the half-normal distribution along with an extra parameter to regulate skewness. The probability density function (pdf) is derived and some various properties of the new distribution are...

Journal: :The Journal of Physical Chemistry A 2011

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