uniform motion
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2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Huabing Cai ◽  
Li-Gang Wang

AbstractWe investigate the influence of atomic uniform motion on radiative energy shifts of a multilevel atom when it interacts with black-body radiation. Our analysis reveals that the atomic energy shifts depend crucially on three factors: the temperature of black-body thermal radiation, atomic velocity, and atomic polarizability. In the low-temperature limit, the presence of atomic uniform motion always enhances the effect of the thermal field on the atomic energy shifts. However, in the high-temperature limit, the atomic uniform motion enhances the effect of the thermal field for an atom polarizable perpendicular to the atomic velocity but weakens it for an atom polarizable parallel to the atomic velocity. Our work indicates that the physical properties of atom–field coupling systems can in principle be regulated and controlled by the combined action of the thermal field and the atomic uniform motion.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261266
Author(s):  
Maëlle Tixier ◽  
Stéphane Rousset ◽  
Pierre-Alain Barraud ◽  
Corinne Cian

A large body of research has shown that visually induced self-motion (vection) and cognitive processing may interfere with each other. The aim of this study was to assess the interactive effects of a visual motion inducing vection (uniform motion in roll) versus a visual motion without vection (non-uniform motion) and long-term memory processing using the characteristics of standing posture (quiet stance). As the level of interference may be related to the nature of the cognitive tasks used, we examined the effect of visual motion on a memory task which requires a spatial process (episodic recollection) versus a memory task which does not require this process (semantic comparisons). Results confirm data of the literature showing that compensatory postural response in the same direction as background motion. Repeatedly watching visual uniform motion or increasing the cognitive load with a memory task did not decrease postural deviations. Finally, participants were differentially controlling their balance according to the memory task but this difference was significant only in the vection condition and in the plane of background motion. Increased sway regularity (decreased entropy) combined with decreased postural stability (increase variance) during vection for the episodic task would indicate an ineffective postural control. The different interference of episodic and semantic memory on posture during visual motion is consistent with the involvement of spatial processes during episodic memory recollection. It can be suggested that spatial disorientation due to visual roll motion preferentially interferes with spatial cognitive tasks, as spatial tasks can draw on resources expended to control posture.


2021 ◽  
Vol 55 ◽  
pp. 44-53
Author(s):  
Misak Shoyan ◽  
◽  
Robert Hakobyan ◽  
Mekhak Shoyan ◽  

In this paper, we present deep learning-based blind image deblurring methods for estimating and removing a non-uniform motion blur from a single blurry image. We propose two fully convolutional neural networks (CNN) for solving the problem. The networks are trained end-to-end to reconstruct the latent sharp image directly from the given single blurry image without estimating and making any assumptions on the blur kernel, its uniformity, and noise. We demonstrate the performance of the proposed models and show that our approaches can effectively estimate and remove complex non-uniform motion blur from a single blurry image.


Author(s):  
Yuri Kopanytsia ◽  
Olena Gizha ◽  
Oksana Nechypor ◽  
Nestan Tavartkiladze

Research and calculations of non-uniform motion are very important from a practical point of view and have certain features for different states of flow, analysis of the shape of free surface curves, as well as the design of many hydraulic structures. When considering these issues, the concepts of specific cross-sectional energy and critical depth are used. The current trend of technology development in the educational process is based on Internet communications, instant online calculations and mobile microprocessor gadgets with appropriate software. The presented experimental project of educational and methodical material with web forms of online calculation of individual tasks is a variant of the modern competitive online environment on the Internet. Further direction of development - addition of methodical video, audio and graphic elements. Analysis of web analytics will gradually simplify the interface and choose the most effective set of modern formats for teaching materials. Computer on-line calculations allow to change the initial data and to introduce elements of modeling and in-depth study of theoretical positions using one typical example in the form of a web form


Author(s):  
A.N. Korshunova ◽  
V.D. Lakhno

Various regimes of a charge motion along a chain in a constant electric field are investigated. This motion is simulated on the basis of the Holstein model. Earlier studies demonstrate a possibility of a uniform motion of a charge in a constant electric field over very long distances. For small values of the electric field intensity a Holstein polaron can move at a constant velocity. As the electric field intensity increases, a charge motion acquires oscillatorily character, performing Bloch oscillations. Since the charge motion depends on the whole set of the system parameters the character of the motion depends not only on the value of the electric field intensity. Therefore, the electric field intensity for which the uniform motion takes place differs for chains with different parameters. The character of the charge motion and distribution is considered in chains with different values of the constant of coupling between the charge and the displacements of the chain. We showed that the values of the electric field intensity for which the regime of a charge motion changes are different in chains with different values of the coupling constant. We also demonstrated that for one and the same value of the electric field intensity, in chains with different values of the coupling constant either a uniform motion or an oscillatory motion, or a stationary polaron can be observed.


Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2283
Author(s):  
Garnet Ord

Minkowski spacetime provides a background framework for the kinematics and dynamics of classical particles. How the framework implements the motion of matter is not specified within special relativity. In this paper we specify how Minkowski space can implement motion in such a way that ’quantum’ propagation occurs on appropriate scales. This is done by starting in a discrete space and explicitly taking a continuum limit. The argument is direct and illuminates the special tension between ’rest’ and ’uniform motion’ found in Minkowski space, showing how the formal analytic continuations involved in Minkowski space and quantum propagation arise from the same source.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Pengcheng Ni ◽  
Xi Luo

With its advantages of high precision, noncontact, and high intelligence, intelligent visual sensor detection technology meets the requirements for online detection of motion status and intelligent recognition of motion images during sports activities, and its applications are becoming more and more extensive. In order to deeply explore the feasibility of using intelligent vision sensor technology to analyze the three-dimensional action of football, this article uses algorithm analysis method, technology summary method, and physical assembly method, collects samples, analyzes the motion model, streamlines the algorithm, and then creates a model based on intelligent visual sensor technology that can analyze the three-dimensional movement in football training. After the experimental objects are selected, the model is established in the ADM environment. All athletes do a uniform motion, the standard input motion speed is 5 m/s, they all move in the opposite direction relative to their respective coordinate axes, and the motion time is 6 seconds. The results show that the movement curves of the athletes in the three coordinate axis directions are basically the same. When the exercise time is 6 seconds, the coordinate values of the athletes on the three coordinate axes are all 0.992 m. We set six intensities in the experiment: 5%, 15%, 25%, 35%, 45%, and 55%. It can be found that as the noise intensity increases from 5% to 45%, the estimation error gradually increases, but as a whole, it is still at a relatively small level. It shows that the algorithm in this paper still has practical significance. It is basically realized that under the guidance of intelligent vision sensor technology, a model can be designed to successfully and efficiently analyze the three-dimensional movement pattern in training.


Author(s):  
Andriy Kravchuk ◽  
Gennadii Kochetov ◽  
Oleksandr Kravchuk

Peculiarities of the diagrams of averaged fluid velocities in the cross-sections of pressure collecting perforated pipelines were determined on the basis of the experimental studies conducted by the authors. The most characteristic typical diagrams of averaged velocities in the pipelines cross-sections with their different design characteristics were given. A comparative analysis of the obtained diagrams with the diagrams of velocities that occur during uniform motion in pressure pipelines with solid walls was carried out. It is shown that the main difference between them occurs in the flow zones, which are located near the pipeline walls. It was explained by the connected liquid jets effect on the main flow. The degree of diagrams deformation was estimated by the value of the momentum coefficient α0 (Boussinesq coefficient) and the coefficient of kinetic energy α (Coriolis coefficient). It was determined that in the general case these coefficients will be variable in magnitude along the length of the studied pipes. Nevertheless, these coefficients are recommended to be constant in magnitude in engineering calculations. The limits of the structural characteristics of collecting perforated pipes for which this non-uniformity of the diagrams must be taken into account, and for which it can be neglected were determined on the basis of the analysis of the equation of fluid motion with a variable flow rate.


2021 ◽  
Vol 2021 ◽  
pp. 1-25
Author(s):  
Sai Zhang ◽  
Zhen Yang

In this paper, a bounded finite-time control strategy is developed for the final proximity maneuver of spacecraft rendezvous and docking exposed to external disturbance and input quantization. To realize the integrated control for spacecraft final proximity operation, the coupling kinematics and dynamics of attitude and position are modeled by feat of Lie group SE 3 . With a view to improving the convergence rate and reducing the chattering, an adaptive finite-time controller is proposed for the error tracking system with one-step theoretical proof of stability. Meanwhile, the hysteresis logarithmic quantizer is implemented to effectively reduce the frequency of data transmission and the quantization errors are reduced under the proposed controller. The algorithms outlined above are based on an integrated model expressed by SE 3 and denoted by uniform motion states, which can simplify the design progress and improve control precision. Finally, simulations are provided to exhibit the effectiveness and advantages of the designed strategy.


2021 ◽  
pp. 108082
Author(s):  
Pei Wang ◽  
Wei Sun ◽  
Qingsen Yan ◽  
Axi Niu ◽  
Rui Li ◽  
...  

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