high dynamics
Recently Published Documents


TOTAL DOCUMENTS

225
(FIVE YEARS 100)

H-INDEX

13
(FIVE YEARS 2)

2021 ◽  
Vol 7 (4) ◽  
pp. 54-62
Author(s):  
A. Kovalsky ◽  
G. Mitryaev ◽  
A. Pitrin

The article develops a methodology for scheduling an orbital channel resource with operational priority assignment based on the calculation of the parameters of a non-Markov service model with a limited residence time of a request in the system, which differs from known methods in that it takes into account the priority of various network subscribers, taking into account the high dynamics of their movement and the average waiting time in the service system with priority in the allocation of the orbital channel resource of the satellite command-relay system. The analysis of the influence of service quality indicators of information data flows is carried out.It is shown that the developed method of priority scheduling makes it possible to meet the requirements for the quality of service. A complex of experimental studies was carried out, which showed the possibility of ensuring the required level of stability with the deterioration in difficult conditions of radio electronic equipment, which made it possible to formulate practical proposals for improving the complex of coordination and distribution of resources of in the satellite command relay system.


2021 ◽  
Vol 12 (1) ◽  
pp. 244
Author(s):  
Vu N. D. Kieu ◽  
Shyh-Chour Huang

Cable-driven parallel robots (CDPRs) have several advantages and have been widely used in many industrial fields, especially industrial applications that require high dynamics, high payload capacity, and a large workspace. In this study, a design model for a CDPR system was proposed, and kinematic and dynamic modeling of the system was performed. Experiments were carried out to identify the dynamic modulus of elastic cables based on the dynamic mechanical analysis (DMA) method. A modified kinematic equation considering cable nonlinear tension was developed to determine the optimal cable tension at each position of the end-effector, and the wrench-feasible workspace was analyzed at various motion accelerations. The simulation results show that the proposed CDPR system obtains a large workspace, and the overall workspace is satisfactory and unrestricted for moving ranges in directions limited by the X-axis and the Y-axis from −0.3 to 0.3 m and by the Z-axis from 0.1 to 0.7 m. The overall workspace was found to depend on the condition of acceleration as well as the moving ranges limited by the end-effector. With an increase in external acceleration, the cable tension distribution increased and reached a maximum in the case of 100 m/s2.


Coasts ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 73-89
Author(s):  
Ivana M. Mingo ◽  
Rafael Almar ◽  
Laurent Lacaze

Low tide terrace (LLT) beaches are characterised by a moderately steep beach face and a flat shallow terrace influencing the local hydro-morphodynamics during low tide. The upper beachface slope (β) and the terrace width (Lt) are the main morphological parameters that define the shape of LTT cross-shore beach profiles. This work aims at better understanding the behaviour of β and Lt and their link with the incoming wave forcing. For this purpose, our results are based on 3.5 years times series of daily beach profiles and wave conditions surveys at two different microtidal LTT beaches with similar sediments size but different wave climate, one at Nha Trang (Vietnam) and the other one at Grand Popo (Benin). While they look similar, two contrasting behaviour were linked to two sub-types of LTT regimes: the first one is surf regulated beaches (SRB) where the swash zone is highly regulated by the surf zone wave energy dissipation on the terrace, and the second is swash regulated beaches (SwRB) acting in more reflective regime where the terrace is not active and the energy dissipation is mainly produced in the swash zone, the terrace becomes a consequences of the high dynamics in the swash zone. Finally, extending the common view of an equilibrium beach profile as a power law of the cross-shore distance, the ability of a simple parametrized cubic function model with the Dean number as unique control parameters is proposed and discussed. This simple model can be used for the understanding of LLT environments but it can not be extended to the whole beach spectrum.


2021 ◽  
Vol 10 (12) ◽  
pp. 800
Author(s):  
Jinming Zhang ◽  
Lianrui Xu ◽  
Cuizhu Bao

The vision-based robot pose estimation and mapping system has the disadvantage of low pose estimation accuracy and poor local detail mapping effects, while the modeling environment has poor features, high dynamics, weak light, and multiple shadows, among others. To address these issues, we propose an adaptive pose fusion (APF) method to fuse the robot’s pose and use the optimized pose to construct an indoor map. Firstly, the proposed method calculates the robot’s pose by the camera and inertial measurement unit (IMU), respectively. Then, the pose fusion method is adaptively selected according to the motion state of the robot. When the robot is in a static state, the proposed method directly uses the extended Kalman filter (EKF) method to fuse camera and IMU data. When the robot is in a motive state, the weighted coefficient is determined according to the matching success rate of the feature points, and the weighted pose fusion (WPF) method is used to fuse camera and IMU data. According to the different states, a series of new poses of the robot are obtained. Secondly, the fusion optimized pose is used to correct the distance and azimuth angle of the laser points obtained by LiDAR, and a Gauss–Newton iterative matching process is used to match the corresponding laser points to construct an indoor map. Finally, a pose fusion experiment is designed, and the EuRoc data and the measured data are used to verify the effectiveness of this method. The experimental results confirm that this method provides higher pose estimation accuracy compared with the robust visual inertial odometry (ROVIO) and visual-inertial ORB-SLAM (VI ORB-SLAM) algorithms. Compared with the Cartographer algorithm, this method provides higher two-dimensional map modeling accuracy and modeling performance.


Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7588
Author(s):  
Huigang Chang ◽  
Nianwen Ning

Connected autonomous vehicles can leverage communication and artificial intelligence technologies to effectively overcome the perceived limitations of individuals and enhance driving safety and stability. However, due to the high dynamics of the vehicular network and frequent interruptions and handovers, it is still challenging to provide stable communication connections between vehicles, which is likely to cause disasters. To address this issue, in this paper, we propose an intelligent clustering mechanism based on driving patterns in heterogeneous Cognitive Internet of Vehicles (CIoVs). In the proposed approach, we analyze the driving mode containing multiple feature parameters to accurately capture the driving characteristics. To ensure the accuracy of pattern recognition, a genetic algorithm-based neural network pattern recognition algorithm is proposed to support the reliable clustering of connected autonomous vehicles. The cognitive engines recognize the driving modes to group vehicles with a similar driving mode into a relatively stable cluster. In addition, we formulate the stability and survival time of clusters and analyze the communication performance of the clustering mechanism. Simulation results show that the proposed mechanism improves the reliable communication throughput and average cluster lifetime by approximately 14.4% and 11.5% respectively compared to the state-of-the-art approaches.


2021 ◽  
Vol 9 ◽  
Author(s):  
Zufei Xiao ◽  
Gang Li ◽  
Yi Zhao ◽  
Keqing Xiao ◽  
Qinglin Chen ◽  
...  

Urbanization and seasonality strongly influence the bacterial composition of the soil. However, aquatic environments such as rivers are understudied owing to their high dynamics and therefore rules relating to more static habitats such as lentic or terrestrial environments may be limited. Here, we compared the spatiotemporal patterns of bacterioplankton communities in the Zhangxi river along a gradient of urbanization using 16S ribosomal DNA identification. The alpha and beta diversity of bacterioplankton showed no significant response to watershed urbanization. A significant difference in predicted functional profiles of the bacterioplankton community was also revealed between the wet and dry seasons. The bacterioplankton community assembly was driven by both deterministic and stochastic processes. Stochasticity was one of the most vital processes affecting the bacterioplankton communities in both wet and dry seasons, explaining over 50% variation in the community by the null model analysis. Bacterioplankton co-occurrence patterns in the river changed with the seasons. More notably, the composition of bacterioplankton communities was inconsistent with alternations of the spatial distance offering meaningful implications for interactions between zero-radius operational taxonomic units and the dynamics of the bacterioplankton communities in surface water. In summary, we found clear patterns of seasonal variations in the bacterioplankton community structures.


2021 ◽  
Vol 16 (3) ◽  
pp. 22-34
Author(s):  
D. M. Kangalakova ◽  
D. A. Rakhmetova

In Kazakhstan, the approach to this area is not sufficiently developed, there is no systematic and scientific justification in the management of intellectual resources of the country and regions. Therefore, Kazakhstan is faced with the urgent issue of creating opportunities for the effective use of intellectual capital in the regions, working out management mechanisms and technologies. The development of the region can be traced to the development of intellectual potential in the region. Given the high intellectual potential of the population living in the region, it can be concluded that this region is not lagging in economic development. To determine the potential of the local population, it is necessary to consider the factors influencing it. In this connection, the purpose of this article is to determine the level of factors affecting intellectual potential in the regions of Kazakhstan. During the study, the methods of observation and comparison, system analysis, synthesis and logic were used. In the course of the analysis, it was revealed that in Almaty, Nur-Sultan, Karaganda region, East Kazakhstan region, the components constituting the intellectual potential show a high dynamics of development. There are also regions with low rates of development of components of intellectual potential, these are Almaty region, Akmola region, Turkestan region. For the complex and varied development of regions, appropriate strategic and tactical management decisions should be made, considering the specifics of each region. The factors identified because of the study can become the basis for developing a methodology for assessing the intellectual potential of regions. The research results can be used in programs and strategic plans aimed at developing the intellectual potential of the regions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pradipta Mukherjee ◽  
Arata Miyazawa ◽  
Shinichi Fukuda ◽  
Toshiharu Yamashita ◽  
Donny Lukmanto ◽  
...  

AbstractWe demonstrate label-free imaging of the functional and structural properties of microvascular complex in mice liver. The imaging was performed by a custom-built Jones-matrix based polarization sensitive optical coherence tomography (JM-OCT), which is capable of measuring tissue’s attenuation coefficient, birefringence, and tiny tissue dynamics. Two longitudinal studies comprising a healthy liver and an early fibrotic liver model were performed. In the healthy liver, we observed distinctive high dynamics beneath the vessel at the initial time point (0 h) and reappearance of high dynamics at 32-h time point. In the early fibrotic liver model, we observed high dynamics signal that reveals a clear network vascular structure by volume rendering. Longitudinal time-course imaging showed that these high dynamics signals faded and decreased over time.


2021 ◽  
Vol 12 ◽  
Author(s):  
Renata Luiza Rosa de Moraes ◽  
Francisco de Menezes Cavalcante Sassi ◽  
Luiz Antonio Carlos Bertollo ◽  
Manoela Maria Ferreira Marinho ◽  
Patrik Ferreira Viana ◽  
...  

Miniature fishes have always been a challenge for cytogenetic studies due to the difficulty in obtaining chromosomal preparations, making them virtually unexplored. An example of this scenario relies on members of the family Lebiasinidae which include miniature to medium-sized, poorly known species, until very recently. The present study is part of undergoing major cytogenetic advances seeking to elucidate the evolutionary history of lebiasinids. Aiming to examine the karyotype diversification more deeply in Pyrrhulina, here we combined classical and molecular cytogenetic analyses, including Giemsa staining, C-banding, repetitive DNA mapping, comparative genomic hybridization (CGH), and whole chromosome painting (WCP) to perform the first analyses in five Pyrrhulina species (Pyrrhulina aff. marilynae, Pyrrhulina sp., P. obermulleri, P. marilynae and Pyrrhulina cf. laeta). The diploid number (2n) ranged from 40 to 42 chromosomes among all analyzed species, but P. marilynae is strikingly differentiated by having 2n = 32 chromosomes and a karyotype composed of large meta/submetacentric chromosomes, whose plesiomorphic status is discussed. The distribution of microsatellites does not markedly differ among species, but the number and position of the rDNA sites underwent significant changes among them. Interspecific comparative genome hybridization (CGH) found a moderate divergence in the repetitive DNA content among the species’ genomes. Noteworthy, the WCP reinforced our previous hypothesis on the origin of the X1X2Y multiple sex chromosome system in P. semifasciata. In summary, our data suggest that the karyotype differentiation in Pyrrhulina has been driven by major structural rearrangements, accompanied by high dynamics of repetitive DNAs.


2021 ◽  
Vol 5 (S1) ◽  
pp. 901-911
Author(s):  
Andrey P. Garnov ◽  
Victoria Yu. Garnova ◽  
Natalia A. Prodanova ◽  
Tamara P. Danko ◽  
Tat’yana A. Arhangel’skaya ◽  
...  

The problems of organizing interactive learning in higher education are discussed, taking into account the prospective introduction of new educational standards. It is noted that the emphasis on the use of professional standards in the existing conditions will lead to a decrease in the creative component of graduate training, and the lack of the possibility of real practice will lead to dogmatism and scholasticism. The high dynamics of technical and technological transformations and transformations of the economic sphere in the Russian Federation against the background of global challenges demonstrates the discrepancy between the paces of individual training of high-class professionals. According to the author, the problem is not the transition beyond the boundaries of habitual work; the main attention should be paid to the "smart" future. Complex technologies require significantly more time than before to master the profession. Domestic specialized education should certainly be linked to the spatial development of Russia, which has a huge territory and corresponding local-territorial specifics. Job security – as a tactical emphasis disappears irrevocably within the borders of the region and the industry, giving way for adaptation to the market of local labor and also rapidly and freely moving capital.


Sign in / Sign up

Export Citation Format

Share Document