نتایج جستجو برای: plant relationship

تعداد نتایج: 933165  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علم و صنعت ایران 1379

در این رساله به ارزیابی عملکرد سیستمهای کنترل دیجیتالˆسیستمهای کنترل با نمونه برداری (sampled-data) پرداخته خواهد شد. بطور خاص ، روش pim (نگاشت سیستم ورودی یا plant input mapping) که تکنیکی جدید در طراحی کنترل کننده های دیجیتال با استفاده از طراحی بعمل آمده در زمان پیوسته است ، مورد بررسی دقیق قرار می گیرد. روش نامبرده دارای خاصیت استقنایی پایداری تضمین شده برای کلیه پریودهای نمونه برداری غیرمع...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس 1388

یکی از مشکلات اساسی در rmmac کلاسیک این است که طراحی سیستماتیک این روش برای plant های ناپایدار امکان پذیر نمی باشد. مشکل اصلی در اینجاست که bpm برای plant های حلقه باز ناپایدار قابل محاسبه نیست. علاوه بر آن، تقسیم سیستماتیک زیرفضای نامعین در rmmac کلاسیک، وابسته به ابزار سنتز µ می باشد و دارای پیچیدگی های نسبتا زیادی است. برای حل مشکلات مذکور، در این تحقیق کنترل تطبیقی مقاوم به روش مدل چندگانه ...

Journal: :The American naturalist 2012
Gita Benadi Nico Blüthgen Thomas Hovestadt Hans-Joachim Poethke

Plant-pollinator networks are systems of outstanding ecological and economic importance. A particularly intriguing aspect of these systems is their high diversity. However, earlier studies have concluded that the specific mechanisms of plant-pollinator interactions are destabilizing and should lead to a loss of diversity. Here we present a mechanistic model of plant and pollinator population dy...

Journal: :Current opinion in plant biology 2004
Przemyslaw Prusinkiewicz

Computational plant models or 'virtual plants' are increasingly seen as a useful tool for comprehending complex relationships between gene function, plant physiology, plant development, and the resulting plant form. The theory of L-systems, which was introduced by Lindemayer in 1968, has led to a well-established methodology for simulating the branching architecture of plants. Many current arch...

Journal: :The New phytologist 2009
Barry H Lomax F Ian Woodward Ilia J Leitch Charles A Knight Janice A Lake

The recent discovery of a strong positive relationship between angiosperm genome size and stomatal guard cell length (GCL) opens the possibility of using plant fossil guard cell size as a proxy for changes in angiosperm genome size over periods of environmental change. The responses of GCL to environmental stimuli are currently unknown and may obscure this predictive relationship. Here, we inve...

2016
Emily Palmer

Studies about the relationship between diversity and stability have reached varying conclusions. I used plant-pollinator interaction data sampled from meadows in the HJ Andrews to examine this relationship. I found a clear reciprocal relationship between the number of species in an interaction network and the connectance of the network, as theoretically expected. The number of plant and pollina...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه مازندران 1388

some researches made in the field of agency problem issue, deal with the role of control systems regarding owners and managers. in this research the relationship between the two control mechanisms, namely the voluntary disclosure (external control mechanism) and outside directors (internal control mechanism), which are reductive of agency problems, has been studied. for this reason, a sample ...

Journal: :Ecology 2008
Jennifer A Schweitzer Joseph K Bailey Dylan G Fischer Carri J LeRoy Eric V Lonsdorf Thomas G Whitham Stephen C Hart

Although soil microbial communities are known to play crucial roles in the cycling of nutrients in forest ecosystems and can vary by plant species, how microorganisms respond to the subtle gradients of plant genetic variation is just beginning to be appreciated. Using a model Populus system in a common garden with replicated clones of known genotypes, we evaluated microbial biomass and communit...

Journal: :Science 2015
Lauchlan H Fraser Jason Pither Anke Jentsch Marcelo Sternberg Martin Zobel Diana Askarizadeh Sandor Bartha Carl Beierkuhnlein Jonathan A Bennett Alex Bittel Bazartseren Boldgiv Ilsi I Boldrini Edward Bork Leslie Brown Marcelo Cabido James Cahill Cameron N Carlyle Giandiego Campetella Stefano Chelli Ofer Cohen Anna-Maria Csergo Sandra Díaz Lucas Enrico David Ensing Alessandra Fidelis Jason D Fridley Bryan Foster Heath Garris Jacob R Goheen Hugh A L Henry Maria Hohn Mohammad Hassan Jouri John Klironomos Kadri Koorem Rachael Lawrence-Lodge Ruijun Long Pete Manning Randall Mitchell Mari Moora Sandra C Müller Carlos Nabinger Kamal Naseri Gerhard E Overbeck Todd M Palmer Sheena Parsons Mari Pesek Valério D Pillar Robert M Pringle Kathy Roccaforte Amanda Schmidt Zhanhuan Shang Reinhold Stahlmann Gisela C Stotz Shu-ichi Sugiyama Szilárd Szentes Don Thompson Radnaakhand Tungalag Sainbileg Undrakhbold Margaretha van Rooyen Camilla Wellstein J Bastow Wilson Talita Zupo

The search for predictions of species diversity across environmental gradients has challenged ecologists for decades. The humped-back model (HBM) suggests that plant diversity peaks at intermediate productivity; at low productivity few species can tolerate the environmental stresses, and at high productivity a few highly competitive species dominate. Over time the HBM has become increasingly co...

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