نتایج جستجو برای: which fitted by gaussian model. estimations were made by ordinary block (45 m×45m) kriging. cross

تعداد نتایج: 9958106  

Journal: :جنگل و فرآورده های چوب 0
عفت رضایی دانشجوی کارشناسی ارشد جنگل داری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران، تهران، ایران رضا اخوان استادیار پژوهش، بخش تحقیقات جنگل، مؤسسۀ تحقیقات جنگل ها و مراتع کشور، تهران، ایران جواد سوسنی استادیار، دانشکدۀ کشاورزی، دانشگاه لرستان، خرم آباد، ایران مهدی پورهاشمی استادیار پژوهش، بخش تحقیقات جنگل، مؤسسۀ تحقیقات جنگل ها و مراتع کشور، تهران، ایران

estimation and mapping of forest resources is a precondition for management, planning and research.this research was conducted to investigate the spatial structure and estimation of crown cover anddensity of an oak forest in the west of iran (loristan province) using kriging interpolation method ofgeostatistics. field sampling was performed based on a 100 m×100 m systematic grid using 2000 m2ci...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

in this study, scour of mashkid bridge pier located in mashkid river of saravan county has been studied and to measure the scour rate, the numerical model hec-ras 4.0 has been used. upon selection of mashkid river as the case study and whereas the studied zone is important with respect to the climatic conditions and showery monsoon raining and flowing the great and destructive floodwaters, ther...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - پژوهشکده علوم انسانی و اجتماعی 1390

this study attempts to investigate the effect of peers’ revision in comparison to that of the teacher, and whether peers’ comments and teachers’ comments facilitate students’ revision? if yes, which one is more effective? also attempts have been made to see which aspects of language are more highlighted by peers versus teachers when commenting. besides, it is investigating the student’s attitud...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی علوم پایه زنجان - دانشکده ریاضی 1393

in this thesis, a structured hierarchical methodology based on petri nets is used to introduce a task model for a soccer goalkeeper robot. in real or robot soccer, goalkeeper is an important element which has a key role and challenging features in the game. goalkeeper aims at defending goal from scoring goals by opponent team, actually to prevent the goal from the opponent player’s attacks. thi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی 1392

flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

Estimating the amount of variation due to spatial dependence at different scales provides a basis for designing effective experiments. Accurate knowledge of spatial structures is needed to inform silvicultural guidelines and management decisions for long term sustainability of forests. Furthermore, geostatistics is a useful tool to describe and draw map the spatial variability and estimation o...

Journal: :caspian journal of environmental sciences 2010
r. akhavan

estimating the amount of variation due to spatial dependence at different scales provides a basis for designing effective experiments. accurate knowledge of spatial structures is needed to inform silvicultural guidelines and management decisions for long term sustainability of forests. furthermore, geostatistics is a useful tool to describe and draw map the spatial variability and estimation of...

Journal: :مرتع و آبخیزداری 0
یوسف نبی پور دانشجوی کارشناسی ارشد آبخیزداری، دانشکده منابع طبیعی، دانشگاه تربیت مدرس مهدی وفاخواه دانشیار، دانشکده منابع طبیعی، دانشگاه تربیت مدرس

rainfall spatial analysis methods are very helpful since there are not enough rainfall gauge stations and watersheds are scattered in large extent. there are many different methods for estimating average precipitation such as; arithmetic method and thiessen polygon. however, the arrangement and location of data and their correlations are not considered by classic methods. thus, geostatistical t...

Journal: :caspian journal of environmental sciences 2010
r. akhavan

this research was conducted to investigate spatial variability and estimate tree attributes in a plantation forest in the caspian region of iran using geostatistical analysis. sampling was performed based on a 50m?125m systematic grid in a maple stand (acer velutinum boiss) 18 years of age using circular samples of 200m2 area. totally, 96 sample plots were measured in 63 hectares and 14.25 hect...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده مهندسی موادو متالورژی 1393

the aim of this paper is eliminating cr(vi) by natural hap. hap is a inexpensive material which is used from bovine critical bone ash in order to remove heavy metal ions like cr(vi). some experiments in different ph are performed (ph=2,3,7). maximum adsorption was appeared at ph=2, dosage=0.3 gr, c0=10 mg/l. cr(vi) removal depends on ph value and initial amount of cr(vi) result of experiments w...

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