نتایج جستجو برای: crop response and principal component analysis

تعداد نتایج: 17445434  

Journal: :journal of biomedical physics and engineering 0
a karimi rahmati control and intelligent processing center of excellence, school of electrical and computer engineering, college of engin s k setarehdan control and intelligent processing center of excellence, school of electrical and computer engineering, college of enginسازمان اصلی تایید شده: دانشگاه تهران (tehran university) b n araabi control and intelligent processing center of excellence, school of electrical and computer engineering, college of enginسازمان اصلی تایید شده: دانشگاه تهران (tehran university)

background: fetal electrocardiography is a developing field that provides valuable information on the fetal health during pregnancy. by early diagnosis and treatment of fetal heart problems, more survival chance is given to the infant. objective: here, we extract fetal ecg from maternal abdominal recordings and detect r-peaks in order to recognize fetal heart rate. on the next step, we find a b...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز 1378

مطالعه توزیع جغرافیایی بارندگی به جهت استفاده وسیع آن در کشاورزی، منابع آب، صنعت، توریسم، احداث و بهره برداری از سدها و نیز علم آبیاری حائز اهمیت می باشد. با استفاده از روش آماری مولفه اصلی ‏‎principal component analysis, oca)‎‏) که در مطالعات هوا و اقلیم شناسی کاربد وسیعیدارد می توان داده های اقلیمی نظیر بارندگی در یک گسترده وسیع جغرافیایی را پهنه بندی کرده و نسبت به کاهش حجم داده ها اقدام نمو...

Journal: :فیزیک زمین و فضا 0
مهدی صادقی دانشجوی کارشناسی ارشد ژئوفیزیک (لرزه شناسی)، دانشگاه صنعتی شاهرود، ایران امین روشندل کاهو استادیار، دانشکده معدن، نفت و ژئوفیزیک، دانشگاه صنعتی شاهرود، ایران حمیدرضا سیاه کوهی استاد، گروه فیزیک زمین، موسسه ژئوفیزیک دانشگاه تهران، ایران علیرضا حیدریان دانشجوی دکتری ژئوفیزیک، موسسه ژئوفیزیک، دانشگاه تهران، ایران

spectral decomposition of time series has a significant role in seismic data processing and interpretation. since the earth acts as a low-pass filter, it changes frequency content of passing seismic waves. conventional representing methods of signals in time domain and frequency domain cannot show time and frequency information simultaneously. time-frequency transforms upgraded spectral decompo...

ابراهیم, فاطمه, ارزانی, احمد, رحیم ملک, مهدی,

Crop wild relatives adaptively diversified for environmental stresses are valuable resources for crop breeding especially for climate change scenarios, supposedly worsening drought and heat conditions. In this study, genetic variation of 54 barley genotypes comprised of 47 H. vulgare spp. spontaneum genotypes collected from west of Iran along with Reyhan cultivar and six F1 hybrids resulted fro...

Journal: :journal of rangeland science 2012
sedigheh zare kia hossein arzani mohammad jafari seyyed akbar javadi ali ashraf jafari

this study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. the study was carried out in steppe rangelands of saveh, markazi province, iran. four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. to study various vegetation and...

Ijaz Rasool Noorka Saeed Rouf Shabir A Shahid

Principal component analysis is a valid method used for data compression and information extraction in a given set of experiments. It is a well-known classical data analysis technique. There are a number of algorithms for solving the problems, some scaling better than others. Wheat ranks as the staple food of most of the nations as well as an agent of poverty reduction, food security and world ...

2016
Roy Frostig Cameron Musco Christopher Musco Aaron Sidford

We show how to efficiently project a vector onto the top principal components of a matrix, without explicitly computing these components. Specifically, we introduce an iterative algorithm that provably computes the projection using few calls to any black-box routine for ridge regression. By avoiding explicit principal component analysis (PCA), our algorithm is the first with no runtime dependen...

Journal: :بوم شناسی کشاورزی 0
قربانعلی رسام ناصر لطیفی افشین سلطانی بهنام کامکار

the effects of land use, crop type and crop management on soil fauna were investigated with survey of four habitats in jajarm. the habitats included rangelands, alfalfa (medicago sativa l.) fields and low-input and high-input of wheat (triticum aestivum l.) fields, each with four sample units. in each sample unit, the macrofauna collected with pitfall traps, sorted and counted in terms of famil...

Journal: :Journal of environmental management 2009
José A Gómez-Limón Laura Riesgo

This paper describes a comparative analysis of alternative methods of constructing composite indicators to measure the sustainability of the agricultural sector. The three methods employed were Principal Component Analysis, the Analytic Hierarchy Process and a Multi-Criteria technique. The comparison focused on the irrigated agriculture of the Duero basin in Spain as a case study, using a datas...

Journal: :American Journal of Applied Mathematics 2016

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