نتایج جستجو برای: ball shaped pine
تعداد نتایج: 113496 فیلتر نتایج به سال:
the ball and beam system is one of the most popular laboratory setups for control education. in this paper, we design a fuzzy pd cascade controller for a ball and beam system using asexual reproduction optimization (aro) technique. the ball & beam system consists of a servo motor, a grooved beam, and a rolling ball. this system utilizes a servo motor to control ball’s position on the beam. chan...
The concurrent discussions of landscape scale restoration among restoration ecologists, and of historic disturbance pattern as a guideline for forest management among forest scientists, offer a unique opportunity for collaboration between these traditionally separated fields. The objective of this study was to review the environmental history, early restoration projects, and current plans to re...
A disk Wang-Bézier type generalized Ball curve is a Wang-Bézier type generalized Ball curve whose control points are disks in a plane. It can be viewed as a parametric curve with error tolerances. In this paper, we discuss the problem of degree reduction of disk Wang-Bézier type generalized Ball curve, that is, bounding disk Wang-Bézier type generalized Ball curves with lower degree disk Wa...
Longleaf pine (Pinus palustris Mill) was once the main southern pine species found throughout the southeastern United States, encompassing approximately 38 million hectares (6). After nearly complete destruction of the longleaf pine ecosystem, restoration efforts in recent years have caused resurgence in the planting of longleaf pine on many state and federal lands (14). Many factors have signi...
Exotic tree pathogens can cause devastating ecological effects on forests that can be exacerbated when infections increase the likelihood of attack by insects. Current high rates of mortality of whitebark pine (Pinus albicaulis Engelm.) are due to white pine blister rust caused by the exotic fungus, Cronartium ribicola J.C. Fisch, and the native mountain pine beetle (Dendroctonus ponderosae Hop...
115 Eastern white pine (Pinus strobus L.) was often associated with oaks (Quercus spp.) on upland sites in presettlement forests of the upper Great Lakes region, but widespread logging and subsequent fires in the late 1800s converted these upland sites to fire-tolerant oak forests. Although white pine regeneration is occurring in these second-growth oak forests, white pine regeneration patterns...
in this paper, we prove that every metric line in the poincare ball model of hyperbolic geometry is exactly a classical line of itself. we also proved nonexistence of periodic lines in the poincare ball model of hyperbolic geometry.
BACKGROUND Several cases of pine nut allergies and anaphylaxis have been reported in the literature, but only few pine nut allergens have been characterized. The aim of this research is to identify through immunoelectrophoretic techniques the major pine nut allergens in a group of children monosensitized to pine nuts. METHODS We studied five children with pine nut allergies and no other sensi...
Etiological studies to determine the cause of decline and death of Pinus spp. in Delaware were initiated in 1980. The pinewood nematode, Bursaphelenchus xylophilus, was found to be the major canse of mortality in Japanese black pine (Pinus thunbergii). When inoculated into healthy 5-yr-old Japanese black pines, B. xylophilus produced typical decline symptoms observed in the field. The xylophilo...
(ed. B.P. Singh) 427 pine (Pinus elliottii var. elliottii). Of note, the former two are also considered to be species of concern for conservation (Erickson et al., 2012) due to long-standing land management practices that have favoured loblolly pine. Similarly to loblolly pine, although on a smaller scale, slash pine has been widely planted and managed for wood and fibre production. Because of ...
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