distribution of points
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Author(s):  
L. P. Ishchuk

The work program and ten-year experience of teaching the educational component “Ornamental plants of the closed ground” in Bila Tserkva National Agrarian University for the specialty 206 “Horticulture” of the bachelors level are analyzed. Considerable attention is paid to the practical training of applicants for higher education, in particular, in terms of production — botanical gardens, arboretums, garden centers and greenhouse complexes. The scale of evaluation of the success of higher applicants and the distribution of points by types of work are presented.


Author(s):  
D. V. Koleda

In the article we consider the spatial distribution of points, whose coordinates are conjugate algebraic numbers of fixed degree. The distribution is introduced using a height function. We have obtained universal upper and lower bounds of the distribution density of such points using an arbitrary height function. We have shown how from a given joint density function of coefficients of a random polynomial of degree n, one can construct such a height function H that the polynomials q of degree n uniformly chosen under H[q] ≤1 have the same distribution of zeros as the former random polynomial.


2021 ◽  
Vol 1 (1) ◽  
pp. 559-565
Author(s):  
Muhammad Faizal Zakaria ◽  
Tira Khasanah Handayani

Tirtoadi sub-district is one of the areas mentioned as being on alert for meteorological drought, which is a condition of not experiencing a day without rain (HTH) for more than 60 days. This research aims to provide information on the presence of subsurface water using geoelectric methods. Data acquisition was carried out at 20 points in Tirtoadi. The distribution of points is random but evenly distributed in the research area. The equipment used is Syscal Jr and the measuring range is 600 m AB, and the direction of the stretch is relatively north to south. The field data obtained are deltas V and I. These data are used to calculate R and Rho. The resistivity value obtained is the apparent resistivity. To obtain a subsurface model of the actual resistivity, it is necessary to perform a 1-D inversion. The inversion is carried out using the Progress V3.0 software. The results obtained in this study are variations in the value of subsurface resistivity. Resistivity of water-containing aquifers ranges between 10 ?m – 50 ?m. The depth of groundwater varies between 50 meters to 80 meters. The thickness of the groundwater varies between 5 meters to 22 meters. The recommended drill point is given at T11 with coordinates 49 S 424996 N 9144372 E because at this point it has the shallowest depth and thick enough thickness.


Author(s):  
D. V. Koleda

We consider the spatial distribution of points, whose coordinates are conjugate algebraic numbers of fixed de- gree and bounded height. In the article the main result of a recent joint work by the author and F. Götze, and D. N. Zaporozhets is extended to the case of arbitrary height functions. We prove an asymptotic formula for the number of such algebraic points lying in a given spatial region. We obtain an explicit expression for the density function of algebraic points under an arbitrary height function.


2021 ◽  
Vol 22 (2) ◽  
pp. 139-147
Author(s):  
Peter E. Rozin ◽  
Yuri A. Smolyaninov

The article is devoted to the actual task of planning the work of a group of different types of spacecraft for remote sensing of the Earth. An enlarged algorithm for solving the planning problem for different types of spacecraft is described. The result of the enlarged algorithm is sought in the form of a set of reference plans for groups of similar spacecraft, thinned out by removing some of the conflicting operations of resetting the sensing data. The characteristics of the developed plans largely depend on the methodology used to account for the impact of cloud cover. The possibility of implementing a methodology based on the use of files of current weather forecasts of hydrometeorological centers downloaded from the Internet in the form of a special application is investigated. The created application is being tested on the real data of the hydrometeorological center downloaded from the American server, which covers a large region, including the European part of Eurasia and part of Africa. An application that simulates the distribution of points within a region estimates the number of points covered by weak cloud cover (20% or less). Based on the results of the simulation, it was found that the proportion of points available for shooting lies in the range from about a quarter to a third. Based on the obtained quantitative estimates, it is concluded that taking into account the influence of cloud cover radically changes the reference plans calculated taking into account only illumination, and affects the structure of the enlarged planning algorithm.


2021 ◽  
Vol 13 (18) ◽  
pp. 3665
Author(s):  
Jaehoon Jung ◽  
Jaebin Lee ◽  
Christopher E. Parrish

A current hindrance to the scientific use of available bathymetric lidar point clouds is the frequent lack of accurate and thorough segmentation of seafloor points. Furthermore, scientific end-users typically lack access to waveforms, trajectories, and other upstream data, and also do not have the time or expertise to perform extensive manual point cloud editing. To address these needs, this study seeks to develop and test a novel clustering approach to seafloor segmentation that solely uses georeferenced point clouds. The proposed approach does not make any assumptions regarding the statistical distribution of points in the input point cloud. Instead, the approach organizes the point cloud into an inverse histogram and finds a gap that best separates the seafloor using the proposed peak-detection method. The proposed approach is evaluated with datasets acquired in Florida with a Riegl VQ-880-G bathymetric LiDAR system. The parameters are optimized through a sensitivity analysis with a point-wise comparison between the extracted seafloor and ground truth. With optimized parameters, the proposed approach achieved F1-scores of 98.14–98.77%, which outperforms three popular existing methods. Further, we compared seafloor points with Reson 8125 MBES hydrographic survey data. The results indicate that seafloor points were detected successfully with vertical errors of −0.190 ± 0.132 m and −0.185 ± 0.119 m (μ ± σ) for two test datasets.


2021 ◽  
pp. 193229682110235
Author(s):  
G. Da Prato ◽  
S. Pasquini ◽  
E. Rinaldi ◽  
T. Lucianer ◽  
S. Donà ◽  
...  

Background: continuous glucose monitoring systems (CGMs) play an important role in the management of T1D, but their accuracy may reduce during rapid glucose excursions. The aim of study was to assess the accuracy of recent rt-CGMs available in Italy, in subjects with T1D during 2 sessions of physical activity: moderate continuous (CON) and interval exercise (IE). Method: we recruited 22 patients with T1D, on CSII associated or integrated with a CGM, to which a second different sensor was applied. Data recorded by CGMs were compared with the corresponding plasma glucose (PG) values, measured every 5 minutes with the glucose analyzer. To assess the accuracy of the CGMs, we evaluated the Sensor Bias (SB), the Mean Absolute Relative Difference (MARD) and the Clarke error grid (CEG). Results: a total of 2355 plasma-sensor glucose paired points were collected. Both average plasma and interstitial glucose concentrations did not significantly differ during CON and IE. During CON: 1. PG change at the end of exercise was greater than during IE ( P = .034); 2. all sensors overestimated PG more than during IE, as shown by SB ( P < .001) and MARD ( P < .001) comparisons. Classifying the performance according to the CEG, significant differences were found between the 2 sessions in distribution of points in A and B zones. Conclusions: the exercise affects the accuracy of currently available CGMs, especially during CON, suggesting, in this circumstance, the need to maintain blood glucose in a “prudent” range, above that generally recommended. Further studies are needed to investigate additional types of activities.


Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1355
Author(s):  
Juan J. Benito ◽  
Ángel García ◽  
María Lucía Gavete ◽  
Mihaela Negreanu ◽  
Francisco Ureña ◽  
...  

In this paper, we show the application of the meshless numerical method called “Generalized Finite Diference Method” (GFDM) for solving a model for tumor growth with nutrient density, extracellular matrix and matrix degrading enzymes, [recently proposed by Li and Hu]. We derive the discretization of the parabolic–hyperbolic–parabolic–elliptic system by means of the explicit formulae of the GFDM. We provide a theoretical proof of the convergence of the spatial–temporal scheme to the continuous solution and we show several examples over regular and irregular distribution of points. This shows the feasibility of the method for solving this nonlinear model appearing in Biology and Medicine in complicated and realistic domains.


2020 ◽  
Vol 13 (6) ◽  
pp. 2908
Author(s):  
Renan Valério Eduvirgem ◽  
Maria Eugênia Moreira Costa Ferreira

O objetivo da pesquisa é avaliar a distribuição espacial do molusco Achatina fulica, espécie exótica, na zona rural do município. Para caracterizar e explicar a ocorrência positiva da espécie foram avaliados os seguintes elementos: localização em coordenada, temperatura, umidade, insolação, altitude e avaliação da arborização/cobertura vegetal. Em campo, foram detectados 40 propriedades rurais que possuem a espécie exótica, dispersa nas proximidades das residências, barracões, e não em meio às culturas temporárias. As entrevistas indicaram que a maior parte dos entrevistados aplicam os procedimentos de contato manual de forma adequada, cujo propósito é evitar a contaminação pelo helminto Angiostrongylus sp. Entretanto, o risco não está isento, pois há pessoas que têm contato com a espécie sem proteção nas mãos e, em mais de 50% das residências há roedores (ratos), que são hospedeiros definitivos do verme. Achatina fulica in rural zone of Maringá, Paraná: environmental relations A B S T R A C TThe objectives of this research are: 1) map the current spatial distribution of the mollusc Achatina fulica in the rural zone and its interaction with the environmental conditions in which they are found in the rural area of the municipality of Maringá, Paraná; 2) evaluate the potential risks to human health through the questionnaires used during the interviews; 3) assess whether the population is vulnerable to contamination by the giant African snail. The methodological procedures were established in the following steps: determining the sample size; distribution of points using the grid to not influence the choice of locations to be interviewed; authorization from the ethics board; field interviews; collections of variables in the field to relate to the snail; organize and tabulate the results; generate cartographic products; promote statistical analysis. 40 rural properties were detected that have the exotic species, dispersed in the vicinity of the residences, sheds, and not among the temporary cultures. The interviews indicated that most of the interviewees apply the procedures of manual contact in an appropriate way, whose purpose is to avoid contamination by the helminth Angiostrongylus sp. The risk is not exempt, as there are people with contact with the species without protection in their hands and, in more than 50% of the residences there are rodents (rats) - according to information raised with the residents. The snail was found at intermediate altitudes with declines of up to 12%. It was concluded that the rural area has favorable environmental conditions for the survival and reproduction of Achatina fulica, however, snails are found in specific places, thus increasing the chances of success in controlling the species.Keywords: Biogeography, environmental analysis, geographic distribution, exotic Species.


2020 ◽  
Vol 637 ◽  
pp. A18 ◽  
Author(s):  
Tony Bonnaire ◽  
Nabila Aghanim ◽  
Aurélien Decelle ◽  
Marian Douspis

Numerical simulations and observations show that galaxies are not uniformly distributed in the universe but, rather, they are spread across a filamentary structure. In this large-scale pattern, highly dense regions are linked together by bridges and walls, all of them surrounded by vast, nearly-empty areas. While nodes of the network are widely studied in the literature, simulations indicate that half of the mass budget comes from a more diffuse part of the network, which is made up of filaments. In the context of recent and upcoming large galaxy surveys, it becomes essential that we identify and classify features of the Cosmic Web in an automatic way in order to study their physical properties and the impact of the cosmic environment on galaxies and their evolution. In this work, we propose a new approach for the automatic retrieval of the underlying filamentary structure from a 2D or 3D galaxy distribution using graph theory and the assumption that paths that link galaxies together with the minimum total length highlight the underlying distribution. To obtain a smoothed version of this topological prior, we embedded it in a Gaussian mixtures framework. In addition to a geometrical description of the pattern, a bootstrap-like estimate of these regularised minimum spanning trees allowed us to obtain a map characterising the frequency at which an area of the domain is crossed. Using the distribution of halos derived from numerical simulations, we show that the proposed method is able to recover the filamentary pattern in a 2D or 3D distribution of points with noise and outliers robustness with a few comprehensible parameters.


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