891 research outputs found
The Effects of Different Intensity of Thinning on the Development in Scots Pine (Pinus sylvestris L.) Stands in Kazakh Uplands
The search for more accurate methods of predicting the growth and development of forest stands became the most urgent task set for foresters of Kazakhstan to determine the permissible interventions in the natural course of the life of plantings, provide high durability and resilience in forests. The aim of the study was to identify the effects of diameter and density of Scots pine stands of Kazakh Uplands on their growth and productivity and the related productivity of single plantation stands taking into account the conditions of growth and development of internal factors as well as further study of the methodology for assessing the forestry cost-effectiveness and improvement thinning. To achieve this aim, effects of varied felling intensities on Scots pine stands were studied. The most common two forest types in upland Scots pine forests were chosen as permanent sample plots; the dead pine-lichen and moss pine-grass. The results showed that improvement thinning of moderate and severe intensity which are more profitable should be done in Scots pine forests of Kazakh Upland as well as carrying out such thinning increases the yield of the larger logs and increases the value of the left stand
Charged Vaidya-Tikekar model for super compact star
In this work, we explore a class of compact charged spheres that have been
tested against experimental and observational constraints with some known
compact stars candidates. The study is performed by considering the
self-gravitating, charged, isotropic fluids which is more pliability in solving
the Einstein-Maxwell equations. In order to determine the interior geometry, we
utilize the Vaidya-Tikekar geometry for the metric potential with
Riessner-Nordstrom metric as an exterior solution. In this models, we determine
constants after selecting some particular values of M and R, for the compact
objects SAX J1808.4-3658, Her X-1 and 4U 1538-52. The most striking consequence
is that hydrostatic equilibrium is maintained for different forces, and the
situation is clarified by using the generalized Tolman-Oppenheimer-Volkoff
(TOV) equation. In addition to this, we also present the energy conditions,
speeds of sound and compactness of stars that are very much compatible to that
for a physically acceptable stellar model. Arising solutions are also compared
with graphical representations that provide strong evidences for more realistic
and viable models, both at theoretical and astrophysical scale.Comment: 13 Pages, 5 Figures and 4 Table
Review of the fast growing forest tree species in Turkey
Los antecedentes de la utilización de especies de
crecimiento rápido en Turquía tienen se remontan a
50 años y en los últimos 35-40 años se ha abrodado
desde un punto de vista científico. Eucalyptus
camaldulensis Dehn., E. grandis W.Hill., Pinus
pinaster Ait., P. radiata D. Don., chopos híbridos,
algunos clones de Populus deltoides Bartr. ex Marsh.
y P. nigra L. son las especies más importantes por su
mayor utilización en ensayos de especies, orígenes y
en plantaciones. Aunque las especies y orígenes
americanas son los más usados en los ensayos, los
resultados esperados no han podido ser alcanzados
debido al bajo número de clones y orígenes,
establecidos en los experimentos que no representan
el área de distribución natural. Junto con estas
especies, los estudios deberían centrarse en Pinus
brutia Ten. que tiene una amplia área de distribución
natural en Turquía, elevado potencial y caracteres
relacionados con el crecimiento rápido. Además, P.
brutia esta considerado como una especie que podría
cubrir el déficit de suministro a largo plazo. También,
los estudios deberían ocuparse de Fraxinus
angustifolia Wahl. subsp. oxycarpa Bieb ex Willd.,
Salix excelsa J. F. Gmelin., S. Alba L., Pterocarya
fraxinifolia Spach. y Alnus glutinosa Gaertn. subsp.
barbata (C. A. Mey.) Yalt que fueron probados en
varias regiones y mostraron mejores características
de crecimiento rápido que otras especies de aliso
indígenas._____________________________________The fast growing species have 50 year-old political
and 35-40 year-old scientific background in Turkey.
Eucalyptus camaldulensis Dehn., E. grandis W.Hill.,
Pinus pinaster Ait., P. radiata D. Don., hybrid
poplars, some clones of Populus deltoides Bartr. ex
Marsh. and P. nigra L. are the most important
species for obtaining a great deal of progress in
species and origin experiments and starting the
plantation phase in Turkey. In fast growing species
process; although the American species and origins
are mostly used, the desired outcomes could not be
achived because of establishing the experiments
with few number of clones and origins, which didn’t
represent the natural distribution area. Along with
these species, studies should be focused on Pinus
brutia Ten. which has broad natural distribution
area in Turkey, improvement potential and fast
growing character. Furthermore, P. brutia is
evaluated as a species which will close the supply
deficit in long run. Also, studies should be
performed on Fraxinus angustifolia Wahl. subsp.
oxycarpa Bieb ex Willd., Salix excelsa J. F.
Gmelin., S. alba L., Pterocarya fraxinifolia Spach.
and Alnus glutinosa Gaertn. subsp. barbata (C. A.
Mey.) Yalt. which was experimented in regional
base and showed the faster growing character than
the other indigenous alder species and native
species
The Finslerian wormhole models
We present models of wormhole under the Finslerian structure of spacetime.
This is a sequel of our previous work (Eur Phys J 75:564, 2015) where we
constructed a toy model for compact stars based on the Finslerian spacetime
geometry. In the present investigation, a wide variety of solutions are
obtained that explore wormhole geometry by considering different choices for
the form function and energy density. The solutions, like the previous work,
are revealed to be physically interesting and viable models for the explanation
of wormholes as far as the background theory and literature are concerned.Comment: 9 pages and 7 figue
IoT Anomaly Detection Methods and Applications: A Survey
Ongoing research on anomaly detection for the Internet of Things (IoT) is a
rapidly expanding field. This growth necessitates an examination of application
trends and current gaps. The vast majority of those publications are in areas
such as network and infrastructure security, sensor monitoring, smart home, and
smart city applications and are extending into even more sectors. Recent
advancements in the field have increased the necessity to study the many IoT
anomaly detection applications. This paper begins with a summary of the
detection methods and applications, accompanied by a discussion of the
categorization of IoT anomaly detection algorithms. We then discuss the current
publications to identify distinct application domains, examining papers chosen
based on our search criteria. The survey considers 64 papers among recent
publications published between January 2019 and July 2021. In recent
publications, we observed a shortage of IoT anomaly detection methodologies,
for example, when dealing with the integration of systems with various sensors,
data and concept drifts, and data augmentation where there is a shortage of
Ground Truth data. Finally, we discuss the present such challenges and offer
new perspectives where further research is required.Comment: 22 page
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