scholarly journals EPENDENCE OF PARAMETERS OF VIRTUAL REGION FROM SUBSTANTIAL FACTORS

2020 ◽  
Vol 30 (1) ◽  
pp. 51-57
Author(s):  
A. N. Volkov ◽  
◽  
A. I. Burmaka ◽  
R. O. Kubitsky ◽  
◽  
...  

In the article is specified, that marine ships considerable part of the operating time work in the straitened districts, in which the width of free passage-way for vessels is limited in the navigation relation by dangers, or intensive navigation. It is marked that in the case of dangerous rapprochement of vessels in the straitened waters at the choice of maneuver of divergence by an operating ship besides a dangerous target it is necessary to take into account preventing ships and navigation dangers in the district of maneuvering, and the existent methods of simultaneous account of dangerous aims and navigation dangers carry analytical character and are bulky and ineffective. The necessity of development of operative and evident methods of warning of collisions of vessels at sailing in the straitened waters is caused to these. The analysis of the last achievements and publications is resulted in work, the decision of the considered problem and selection of parts unsolved before is begun in which. It is shown that binary coordination is the basic method of description of cooperation of pair of the dangerously drawn together vessels, urgent strategies of divergence are considered, the structure of which depends on the conduct of target in the process of divergence, the analysis of procedures of account of navigation dangers is also produced by an analytical method for different types of navigation dangers. Procedure of transformation of the ship safe region set in space of relative motion is offered, in space of veritable motion, a virtual region is formed as a result. It is indicated, that basic properties of virtual regions are: rapprochements of ship with a target dangerous, when the current area of programmatic trajectory of motion of ship gets in the virtual region of target; distance of the shortest rapprochement of ship with a dangerous target will be equal to the set minimum-possible distance of rapprochement, if direction of current area of programmatic trajectory of motion of ship is tangent to the border of virtual region; equality of distance of the shortest rapprochement of ship with a target and set minimum-possible distance of rapprochement is saved at the following of ship on a virtual region tangent to the border to the moment of the shortest rapprochement. It is shown in the publication, that by the computer program dependences of position and form of virtual region on the relation of speeds of ship and target were explored, from distance between a ship and target, and also from bearing on a target. It is shown that depending on distance between a ship and target at the unchanging bearing a virtual region occupies unchanging position in relation to the line of programmatic way of ship, and position and sizes of virtual region depend on bearing on a target.

2018 ◽  
Vol 10 (7) ◽  
pp. 2457 ◽  
Author(s):  
Christina Jönsson ◽  
Oscar Levenstam Arturin ◽  
Anne-Charlotte Hanning ◽  
Rebecka Landin ◽  
Emma Holmström ◽  
...  

The topic of shedding of micro-sized polymeric particles, so called microplastics, from textiles has been covered by an increasing number of studies over the past years. However, the methods with which the shedding of microplastics from textiles has been measured so far has shown a large variation. Consequently, the results regarding the amount of shed particles also vary, from 120 to 728,289 particles from similar garments in recent studies. This article presents research enabling for identification of whether the shedding of microplastics from different types of fabric was dependent on construction parameters. As none of the methods in the existing literature could be used for evaluating shedding of microplastics from textiles, a method was developed for this purpose. The resulting final method is described in this paper as well as the work with minimizing the error sources and consequently the standard deviation of the results through selection of material samples, equipment and procedure for sample preparation, washing, filtering the washing water and analyzing the shed microplastics. Comparing the environmental load of different garments, or identifying improvement possibilities in garment construction are two examples of how the method can be utilized.


2021 ◽  
Vol 13 (4) ◽  
pp. 2146
Author(s):  
Anik Gupta ◽  
Carlos J. Slebi-Acevedo ◽  
Esther Lizasoain-Arteaga ◽  
Jorge Rodriguez-Hernandez ◽  
Daniel Castro-Fresno

Porous asphalt (PA) mixtures are more environmentally friendly but have lower durability than dense-graded mixtures. Additives can be incorporated into PA mixtures to enhance their mechanical strength; however, they may compromise the hydraulic characteristics, increase the total cost of pavement, and negatively affect the environment. In this paper, PA mixtures were produced with 5 different types of additives including 4 fibers and 1 filler. Their performances were compared with the reference mixtures containing virgin bitumen and polymer-modified bitumen. The performance of all mixes was assessed using: mechanical, hydraulic, economic, and environmental indicators. Then, the Delphi method was applied to compute the relative weights for the parameters in multi-criteria decision-making methods. Evaluation based on distance from average solution (EDAS), technique for order of the preference by similarity to ideal solution (TOPSIS), and weighted aggregated sum product assessment (WASPAS) were employed to rank the additives. According to the results obtained, aramid pulp displayed comparable and, for some parameters such as abrasion resistance, even better performance than polymer-modified bitumen, whereas cellulose fiber demonstrated the best performance regarding sustainability, due to economic and environmental benefits.


2021 ◽  
Vol 11 (11) ◽  
pp. 5235
Author(s):  
Nikita Andriyanov

The article is devoted to the study of convolutional neural network inference in the task of image processing under the influence of visual attacks. Attacks of four different types were considered: simple, involving the addition of white Gaussian noise, impulse action on one pixel of an image, and attacks that change brightness values within a rectangular area. MNIST and Kaggle dogs vs. cats datasets were chosen. Recognition characteristics were obtained for the accuracy, depending on the number of images subjected to attacks and the types of attacks used in the training. The study was based on well-known convolutional neural network architectures used in pattern recognition tasks, such as VGG-16 and Inception_v3. The dependencies of the recognition accuracy on the parameters of visual attacks were obtained. Original methods were proposed to prevent visual attacks. Such methods are based on the selection of “incomprehensible” classes for the recognizer, and their subsequent correction based on neural network inference with reduced image sizes. As a result of applying these methods, gains in the accuracy metric by a factor of 1.3 were obtained after iteration by discarding incomprehensible images, and reducing the amount of uncertainty by 4–5% after iteration by applying the integration of the results of image analyses in reduced dimensions.


2021 ◽  
pp. 1-21
Author(s):  
Muhammad Shabir ◽  
Rimsha Mushtaq ◽  
Munazza Naz

In this paper, we focus on two main objectives. Firstly, we define some binary and unary operations on N-soft sets and study their algebraic properties. In unary operations, three different types of complements are studied. We prove De Morgan’s laws concerning top complements and for bottom complements for N-soft sets where N is fixed and provide a counterexample to show that De Morgan’s laws do not hold if we take different N. Then, we study different collections of N-soft sets which become idempotent commutative monoids and consequently show, that, these monoids give rise to hemirings of N-soft sets. Some of these hemirings are turned out as lattices. Finally, we show that the collection of all N-soft sets with full parameter set E and collection of all N-soft sets with parameter subset A are Stone Algebras. The second objective is to integrate the well-known technique of TOPSIS and N-soft set-based mathematical models from the real world. We discuss a hybrid model of multi-criteria decision-making combining the TOPSIS and N-soft sets and present an algorithm with implementation on the selection of the best model of laptop.


2021 ◽  
Vol 13 (5) ◽  
pp. 956
Author(s):  
Florian Mouret ◽  
Mohanad Albughdadi ◽  
Sylvie Duthoit ◽  
Denis Kouamé ◽  
Guillaume Rieu ◽  
...  

This paper studies the detection of anomalous crop development at the parcel-level based on an unsupervised outlier detection technique. The experimental validation is conducted on rapeseed and wheat parcels located in Beauce (France). The proposed methodology consists of four sequential steps: (1) preprocessing of synthetic aperture radar (SAR) and multispectral images acquired using Sentinel-1 and Sentinel-2 satellites, (2) extraction of SAR and multispectral pixel-level features, (3) computation of parcel-level features using zonal statistics and (4) outlier detection. The different types of anomalies that can affect the studied crops are analyzed and described. The different factors that can influence the outlier detection results are investigated with a particular attention devoted to the synergy between Sentinel-1 and Sentinel-2 data. Overall, the best performance is obtained when using jointly a selection of Sentinel-1 and Sentinel-2 features with the isolation forest algorithm. The selected features are co-polarized (VV) and cross-polarized (VH) backscattering coefficients for Sentinel-1 and five Vegetation Indexes for Sentinel-2 (among us, the Normalized Difference Vegetation Index and two variants of the Normalized Difference Water). When using these features with an outlier ratio of 10%, the percentage of detected true positives (i.e., crop anomalies) is equal to 94.1% for rapeseed parcels and 95.5% for wheat parcels.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Kangkang Zha ◽  
Xu Li ◽  
Zhen Yang ◽  
Guangzhao Tian ◽  
Zhiqiang Sun ◽  
...  

AbstractArticular cartilage is susceptible to damage but hard to self-repair due to its avascular nature. Traditional treatment methods are not able to produce satisfactory effects. Mesenchymal stem cells (MSCs) have shown great promise in cartilage repair. However, the therapeutic effect of MSCs is often unstable partly due to their heterogeneity. Understanding the heterogeneity of MSCs and the potential of different types of MSCs for cartilage regeneration will facilitate the selection of superior MSCs for treating cartilage damage. This review provides an overview of the heterogeneity of MSCs at the donor, tissue source and cell immunophenotype levels, including their cytological properties, such as their ability for proliferation, chondrogenic differentiation and immunoregulation, as well as their current applications in cartilage regeneration. This information will improve the precision of MSC-based therapeutic strategies, thus maximizing the efficiency of articular cartilage repair.


2021 ◽  
Vol 53 (1) ◽  
pp. 251-278
Author(s):  
Adrián González Casanova ◽  
Juan Carlos Pardo ◽  
José Luis Pérez

AbstractIn this paper, we introduce a family of processes with values on the nonnegative integers that describes the dynamics of populations where individuals are allowed to have different types of interactions. The types of interactions that we consider include pairwise interactions, such as competition, annihilation, and cooperation; and interactions among several individuals that can be viewed as catastrophes. We call such families of processes branching processes with interactions. Our aim is to study their long-term behaviour under a specific regime of the pairwise interaction parameters that we introduce as the subcritical cooperative regime. Under such a regime, we prove that a process in this class comes down from infinity and has a moment dual which turns out to be a jump-diffusion that can be thought as the evolution of the frequency of a trait or phenotype, and whose parameters have a classical interpretation in terms of population genetics. The moment dual is an important tool for characterizing the stationary distribution of branching processes with interactions whenever such a distribution exists; it is also an interesting object in its own right.


2021 ◽  
Author(s):  
Mohammed Gamal ◽  
Ibrahim A. Naguib ◽  
Dibya Sundar Panda ◽  
Fatma F. Abdallah

The competencies of four greenness assessment tools were tested. AGREE is the best greenness tool while NEMI is the poorest one. AGREE, GAPI, and ESA are reliable greenness tools.


2021 ◽  
Author(s):  
Deborah Martínez ◽  
Rafael Guzmán-Cabrera ◽  
Daniel A. May-Arrioja ◽  
Iván Hernández-Romano ◽  
Miguel Torres-Cisneros

Author(s):  
Shweta Rani ◽  
Bharti Suri

Mutation testing is a successful and powerful technique, specifically designed for injecting the artificial faults. Although it is effective at revealing the faults, test suite assessment and its reduction, however, suffer from the expense of executing a large number of mutants. The researchers have proposed different types of cost reduction techniques in the literature. These techniques highly depend on the inspection of mutation operators. Several metrics have been evolved for the same. The selective mutation technique is most frequently used by the researchers. In this paper, the authors investigate different metrics for evaluating the traditional mutation operators for Java. Results on 13 Java programs indicate how grouping few operators can impact the effectiveness of an adequate and minimal test suite, and how this could provide several cost benefits.


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