scholarly journals DEVELOPMENT OF OPTIMAL PLANTING SCHEMES BY SIMULATION

ÈKOBIOTEH ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 418-423
Author(s):  
A.N. Kolobov ◽  
◽  
E.Ya. Frisman ◽  

One way to increase the productivity of artificial forestation is to control the density and relative position of trees. In this regard, there are tasks of finding the optimal planting schemes to obtain the maximum wood stock of a given diameter. Based on the developed simulation model, a comparative analysis of the productivity of spruce stands with different planting schemes was carried out. The optimal forest planting schemes for spruce stands, which provide the maximum stock of small, medium and large wood, are determined. It is shown that in order to maximize the stock of wood of different size classes, different initial planting densities are required. The higher the size classes of the grown wood, the lower the optimal planting density.

2021 ◽  
Vol 24 (2-3) ◽  
pp. 192-195
Author(s):  
A.N. Kolobov

The author has carried out a comparative analysis of spruce stands productivity for different planting schemes based on imitation modeling. He shows that the process of the stand self-thinning depends both on the initial density of planting and on the trees relative position on the site, which ultimately determines the amount of a given diameter wood stock. It is determined the optimal forest planting schemes for spruce stands providing the maximum stock of small, medium and large wood.


2017 ◽  
Vol 13 (3) ◽  
pp. 68-78
Author(s):  
A. A. Pavlov ◽  
I. O. Datyev ◽  
M. G. Shishaev

Simulation is the main way for testing technologies in the field of multi-hop wireless networks (MWN). Creating a simulation model MWN - a time-consuming task associated with the use of specialized software tools, called network simulators. In this paper, the modern experience of modeling MWN and the main problems are formulated. One of the main problem is the comparative analysis' impossibility of the experiments results conducted by various researchers. This is due to the reasons associated with the models used for testing, the planning an imitation experiment and the principal differences in the network simulators. To solve this problem, authors propose a generalized conceptual model of MWN simulation and a specialized software package that automates the execution of experiment series in a heterogeneous modeling environment.


Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1134 ◽  
Author(s):  
Andreas Zischg ◽  
Niccolo Galatioto ◽  
Silvana Deplazes ◽  
Rolf Weingartner ◽  
Bruno Mazzorana

Large wood (LW) can lead to clogging at bridges and thus cause obstruction, followed by floodplain inundation. Moreover, colliding logs can cause severe damage to bridges, defense structures, and other infrastructure elements. The factors influencing spatiotemporal LW dynamics (LWD) during extreme floods vary remarkably across river basins and flood scenarios. However, there is a lack of methods to estimate the amount of LW in rivers during extreme floods. Modelling approaches allow for a reliable assessment of LW dynamics during extreme flood events by determining LW recruitment, transport, and deposition patterns. Here, we present a method for simulating LWD on a river reach scale implemented in R (LWDsimR). We extended a previously developed LW transport model with a tree recognition model on the basis of Light Detection and Ranging (LiDAR) data for LW recruitment simulation. In addition, we coupled the LWD simulation model with the hydrodynamic simulation model Basic Simulation Environment for Computation of Environmental Flow and Natural Hazard Simulation (BASEMENT-ETH) by adapting the existing LW transport model to be used on irregular meshes. The model has been applied in the Aare River basin (Switzerland) to quantify mobilized LW volumes and the associated flow paths in a probable maximum flood scenario.


1983 ◽  
Vol 25 (6) ◽  
pp. 642-650 ◽  
Author(s):  
C. L. Richer ◽  
R. Drouin ◽  
M. Murer-Orlando ◽  
P. Jean

The schematic representation of RHG-banded chromosomes (R-banding was produced by heat denaturation followed by Giemsa staining (RHG)) in the 850-band range per haploid set, was prepared showing the relative position, the specific size, and the characteristic staining intensity for each band. To this idiogram was adapted the new International Standard Cytogenetic Nomenclature. Our aim was to produce a realisitic idiogram which could help in the preparation of R-banded prophase karyotypes and in the localization of chromosomal rearrangements. A comparative analysis of bands at prophase and metaphase revealed certain aspects of the dynamics involved in chromosome condensation and in R-band organization. The effect of chromosome elongation on the appearance of R-bands within heterochromatic regions has also been discussed.


Author(s):  
B. I. Shakhtarin ◽  
T. G. Aslanov ◽  
U. R. Tetakaev

Objectives. To study the dependencies obtained when determining the coordinates of an earthquake hypocentre using the figures of fourth and second orders.Method. A comparative analysis of determining the coordinates of the earthquake focus using the Cassini oval method, both taking errors in the readings of seismic sensors into account the and ignoring them, is presented.Result. A new method is proposed for determining the coordinates of the earthquake hypocentre, which uses the fourth-order figure, the Cassini oval, in the calculations. A graph is obtained for the distribution of errors in determining the coordinates of the earthquake focus (using the Cassini oval) depending on the relative position of two seismic sensors with different values of their errors in determining the difference in travel times of seismic waves.Conclusion. Since the calculation results are independent of the error sign in determining the difference in the arrival times of seismic waves, the method is suitable for the initial determination of the coordinates of the earthquake hypocentre as well as for comparison with the results of other methods for identifying the error sign. 


Author(s):  
И.В. Никифорчин ◽  
М.О. Гурьянов ◽  
Д.А. Шулыгина

В последние годы снизилось качество работ по отводу и таксации лесосек. Существующие и применяемые в таксации методы не обеспечивают необходимую точность конечных результатов, поскольку их использование часто не соответствует требованиям «Наставления по отводу и таксации лесосек». Таким образом, актуальной задачей становится изучение ошибок в определении товарной структуры древостоев и выявление возможных причин их возникновения с целью дальнейшего совершенствования лесотаксационных работ. На основании материалов таксации постоянных пробных площадей ели европейской была выполнена материально-денежная оценка древостоев по сортиментным и товарным таблицам, произведен расчет грубых, систематических и случайных ошибок выхода крупной, средней, мелкой деловой древесины, дров, ликвидной древесины и отходов. Для оценки влияния различных факторов на появление и величину ошибок были выполнены корреляционный и однофакторный дисперсионный анализы. Проведенный анализ позволил установить, что основными показателями, оказывающими влияние на расхождения в выходе сортиментов различных категорий древесины, при использовании товарных и сортиментных таблиц, являются средние высоты древостоев, а также разряды высот. Это связано с малым числом значений высот, представленных для каждой из ступеней толщины в товарных таблицах. Сортиментные таблицы, в силу большей вариабельности данного таксационного показателя, позволяют более точно определять товарную структуру древостоев. Выявленные закономерности демонстрируют необходимость совершенствования сортиментных и товарных таблиц для уменьшения расхождения получаемых результатов с фактическим выходом сортиментов, что позволит повысить качество лесотаксационных работ. In recent years, the quality of work on the allocation and taxation of cutting areas has decreased. Existing methods used in the taxation do not provide the required accuracy of results since their application often does not meet the criteria of the “Manual on the allocation and taxation of cutting areas”. Thus, the study of errors in determining the product structure of forest stands as well as identifying possible causes for their occurrence in order to improve forest taxation works becomes an urgent task. Based on the taxation materials of the permanent European spruce plots, material and monetary assessment of the stands was made using assortment and commodity tables, and gross, systematic, and random errors of the output of large, medium, small commercial timber, firewood, liquid wood, and waste were calculated. Сorrelation analysis and one-way analysis of variance were performed to assess the influence of various factors on the appearance and magnitude of the errors. The analysis made it possible to establish that the main indicators that influence the discrepancies in the output of assortments of different categories of wood, when using commodity and assortment tables, are the average heights of stands, as well as height categories. This is due to the small number of height values presented for each of the thickness steps in the product tables. Assortment tables, due to the greater variability of this taxation indicator, allow you to more accurately determine the product structure of stands. The revealed patterns demonstrate the high need to improve assortment and commodity tables in order to reduce the discrepancy between obtained results and the actual output of assortments, which will improve the quality of forest taxation work.


1987 ◽  
Vol 15 (16) ◽  
pp. 6515-6538 ◽  
Author(s):  
Giorgio Briner ◽  
Eliane Müller ◽  
Heinz Neuhaus ◽  
Eduard Back ◽  
Fritz Müller ◽  
...  

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