Motion In Region Research Articles

An Effective Method for Forest Fire Smoke Detection

This paper focuses on smoke detection in forest environments. In this paper, dark channel prior and OTSU based multi-threshold are used to find the disturbances such as sky and haze. These regions are blocked to reduce false alarm rate. A motion detection method based on frame difference is adapted to find the motion objects. Color moments, HOG and LBP are chosen as features of smoke and SVM is used as the classification. To reduce more false alarms, the motion regions are classified for several consecutive frames. They won’t be regarded as smoke regions unless M frames of them are classified as smoke ones. Experiment results showed that the proposed method can detect smoke in video effectively and work real-timely.

Chaotic vibrations of nonlinear viscoelastic plate with fractional derivative model and subjected to parametric and external excitations

This paper deals with the analysis of chaotic vibrations of simply supported nonlinear viscoelastic plate with fractional derivative model and subjected to parametric and external excitations. The Galerkin decomposition is used to obtain the modal equation of the system. Using the Melnikov's theorem, the criterion for appearance of horseshoes chaos from homoclinic bifurcation is presented. The Melnikov's predictions are confirmed by using the numerical simulation based on the basin of attraction of initial conditions. It is observed that the region of regular motions increases with the fractional order and decreases with the amplitude of parametric excitation. Moreover, it is found that the increase of the viscoelastic parameter contributes to control the chaos. The bifurcation diagrams and maximal Lyapunov exponent are used to show how the system parameters can affect the dissipative chaos.

Generalization of Störmer Theory for an Axisymmetric Superposition of Dipole and Quadrupole Fields

AbstractClassical Störmer theory is generalized to the case of an axisymmetric superposition of dipole and quadrupole fields. The basic laws of the charged particle motion in certain azimuthally symmetric magnetic configurations are investigated. The allowed and forbidden regions of particle motion, and also the capture regions, which ensure the stable existence of radiation belts, are identified.

Heterogeneous Oblate Primaries in Photo-gravitational CR5BP with Kite Configuration

This paper presents the investigation of the motion of infinitesimal body in the circular restricted five-body problem in which four bodies are taken as heterogeneous oblate spheroid with different densities in three layers and sources of radiation pressure. These four primaries are moving on the circumference of a circle and form a kite configuration. After evaluating the equations of motion and Jacobi-integral, we study the numerical part of the paper such as equilibria, zero-velocity curves and regions of motion. Finally, we examine the stability of the equilibria and observed that all the equilibria are unstable.

Influence of the Local Field and Dipole-Dipole Interactions on the Spectral Characteristics of Simple Metals and Their Nanoparticles

The effect of dipole-dipole interactions of free electrons on the spectral characteristics of simple metals and their nanoparticles is analyzed using Drude theory and the model of the Lorentz local field. It is established that accounting for the dispersion of a local field under conditions of one-dimensional (1D) confinement based on the optical constants of the bulk metal allows the determination of its spectral micro-characteristics in the frequency region of the longitudinal collective motions of the free electrons. This corresponds to the spectra of the dielectric losses of bulk plasma oscillations. A similar procedure for three-dimensional (3D) confinement produces the spectrum of dielectric losses at the frequency of localized plasma oscillations. Using a number of simple metal examples, viz., Li, Na, and K, and also Al, Be, and Mg, it is shown that the frequencies of volume and localized plasma oscillations obtained from a model of dispersion of the local field in the long-wave limit are in good agreement with the actual frequencies of the plasma oscillations of the corresponding metals and the absorption maxima of their nanoparticles with a radius of 2–20 nm. It is shown that the frequencies of the main mode of longitudinal plasma oscillations and the absorption frequency of localized plasmons are well described using the dynamic theory of crystal lattice vibrations.

Egomotion-related visual areas respond to active leg movements.

Monkey neurophysiology and human neuroimaging studies have demonstrated that passive viewing of optic flow stimuli activates a cortical network of temporal, parietal, insular, and cingulate visual motion regions. Here, we tested whether the human visual motion areas involved in processing optic flow signals simulating self-motion are also activated by active lower limb movements, and hence are likely involved in guiding human locomotion. To this aim, we used a combined approach of task-evoked activity and resting-state functional connectivity by fMRI. We localized a set of six egomotion-responsive visual areas (V6+, V3A, intraparietal motion/ventral intraparietal [IPSmot/VIP], cingulate sulcus visual area [CSv], posterior cingulate sulcus area [pCi], posterior insular cortex [PIC]) by using optic flow. We tested their response to a motor task implying long-range active leg movements. Results revealed that, among these visually defined areas, CSv, pCi, and PIC responded to leg movements (visuomotor areas), while V6+, V3A, and IPSmot/VIP did not (visual areas). Functional connectivity analysis showed that visuomotor areas are connected to the cingulate motor areas, the supplementary motor area, and notably to the medial portion of the somatosensory cortex, which represents legs and feet. We suggest that CSv, pCi, and PIC perform the visual analysis of egomotion-like signals to provide sensory information to the motor system with the aim of guiding locomotion.

Multi-level features fusion and selection for human gait recognition: an optimized framework of Bayesian model and binomial distribution

A biometric classification system is utilized to judge the features of human expression by recognizing distinct parameters. Human Gait Recognition (HGR) is a current research area which is mostly used for various security applications such as video surveillance etc. HGR is also utilized in medical imaging for the investigation of several diseases such as Parkinson disease which is identified by gait features. Still, various challenges occur in this domain that affects system accuracies such as shoe type, change in angle, load carriage and change in walking speed. In this research, a new approach for HGR is proposed which is based on Quartile Deviation of Normal Distribution (QDoND) for human extraction and Bayesian model along with Binomial Distribution for features fusion and best features selection. Initially, in the pre-processing step, the most excellent channel is selected and its motion flow is estimated. The motion regions are extracted by QDoND that are later utilized for shape and texture feature extraction. Afterward, the extracted features are fused by a Bayesian model based on their similarity index. Finally, BDs based best features are selected and recognition is performed on the basis of best features using multi-class support vector machine. Four publicly and famous datasets are utilized for the evaluation of proposed system such as AVA multi-view gait (AVAMVG), CASIA A, CASIA B and CASIA C having an accuracy rate of 100%, 98.8%, 87.7%, and 91.6% respectively. The results reveal that the proposed method outperforms in contrast to existing methods.

The effect of small perturbations in the Coriolis and centrifugal forces in the axisymmetric restricted five-body problem

In the framework of the axisymmetric problem of restricted five bodies, the existence and stability of the libration points, the regions of possible motion are illustrated and analyzed numerically, under the effect of small perturbations in the Coriolis and centrifugal forces. It is explored how the parameters influence substantially the positions of the libration points and the possible regions of motion. In an attempt to understand how the parameters involved due to the small perturbations in the Coriolis and centrifugal forces affect the stability of the libration points, we perform a systematic investigation and reveal that some of the collinear and non-collinear libration points are stable under these perturbations, whereas none of these libration points are stable for any combination of the angle parameters when the effects of these forces are neglected.

Numerical and experimental study of dynamics of two pendulums under a magnetic field

In this article, a two-degree-of-freedom system consisting of two pendulums with magnets embedded in a variable magnetic field is investigated experimentally and numerically. Pivots of the pendulums are coupled by an elastic element. The magnetic interaction originates from permanent magnets, mounted at free ends of the pendulums and current-powered air coils underneath. A novel model for the magnetic force is proposed and verified experimentally. Nonlinear dynamics of the system is examined by means of time series, bifurcation diagrams, phase portraits, and Poincaré sections. Regions of chaotic and regular motion are predicted numerically and justified experimentally. Multiperiodic motion and coexisting solutions are detected, and pictures in basins of their attraction are reported, among other.

Temperature Dependence of the Electron Paramagnetic Resonance Spectrum of Asphaltenes from Venezuelan Crude Oils and Their Vacuum Residues

The electron paramagnetic resonance (EPR) technique is used to evaluate the temperature dependence of the aggregation processes in asphaltenes of heavy and extra-heavy crude oils and their vacuum residues from the Venezuelan Oil Belt. All of the EPR spectra of the samples studied show an intense central signal assigned to free radicals (FRs) and a multiplet as a result of the presence of a V+4 porphyrin. From the analyses of the inverse of the normalized area as a function of the temperature for the FR signal and the most intense peak in the vanadium multiplet, we obtain a set of temperatures related to the transition of fast-to-slow motion regions, the temperature of generation–recombination of FRs, and the cracking temperature in all of the samples. On the other hand, applying a Curie–Weiss law, we obtain the order–disorder temperatures and correlated them with the American Petroleum Institute grade of the samples. A computational simulation was performed to propose possible conformers based on the expe...

Nonlinear aspects of focusing internal waves

When a torus oscillates horizontally in a linearly stratified fluid, the wave rays form a double cone, one upward and one downward, with two focal points where the wave amplitude has a maximum due to wave focusing. Following a former study on linear aspects of wave focusing (Ermanyuk et al., J. Fluid Mech., vol. 813, 2017, pp. 695–715), we here consider experimental results on the nonlinear aspects that occur in the focal region below the torus for higher-amplitude forcing. A new non-dimensional number that is based on heuristic arguments for the wave amplitude in the focal area is presented. This focusing number is defined as $Fo=(A/a)\unicode[STIX]{x1D716}^{-1/2}f(\unicode[STIX]{x1D703})$, with oscillation amplitude $A$, $f(\unicode[STIX]{x1D703})$ a function for the variation of the wave amplitude with wave angle $\unicode[STIX]{x1D703}$, and $\unicode[STIX]{x1D716}^{1/2}=\sqrt{b/a}$ the increase in amplitude due to the focusing, with $a$ and $b$, respectively, the minor and major radius of the torus. Nonlinear effects occur for $Fo\geqslant 0.1$, with the shear stress giving rise to a mean flow which results in the focal region in a central upward motion partially surrounded by a downward motion. With increasing $Fo$, the Richardson number $Ri$ measured from the wave steepness monotonically decreases. Wave breaking occurs at $Fo\approx 0.23$, corresponding to $Ri=0.25$. In this regime, the focal region is unstable due to triadic wave resonance. For the different tori sizes under consideration, the triadic resonant instability in these three-dimensional flows resembles closely the resonance observed by Bourget et al. (J. Fluid Mech., vol. 723, 2013, pp. 1–20) for a two-dimensional flow, with only minor differences. Application to internal tidal waves in the ocean are discussed.

The Asymmetry of Vertical Velocity in Current and Future Climate

AbstractA fundamental aspect of vertical velocities in the atmosphere is their asymmetric nature, with stronger upward than downward motions. Here we study this asymmetry from a synoptic‐scale perspective, by employing a storm‐tracking algorithm in observations and climate change simulations. We show that midlatitude cyclones and anticyclones are both skewed toward stronger upward motions, and that this asymmetry intensifies in a warmer climate. Downward motions are generally influenced by changes in the dry static stability, which increases in a warmer climate, and therefore weaken. However, upward motions are influenced by a reduced static stability, which takes into account the influence of latent heating on saturated ascent. The latter decreases locally in regions of upward motions, especially for strong cyclones, leading to an intensification of the upward velocity. The projected increase in the upward velocity of strong storms has potential implications for extreme midlatitude precipitation events.

The Restricted Five-Body Problem With Cyclic Kite Configuration

ABSTRACTThis manuscript investigates the five-body problem with kite configuration where four bodies are placed at the vertices of a kite. All the vertices of kite are taken at the circumference of a circle. These four bodies are considered as primaries which are moving on the circle with same centre which is taken as origin. The fifth infinitesimal body is moving in the space under the influences of these four primaries but not influencing them. After evaluating the equations of motion of the infinitesimal body, we have determined the Jacobi-integral. In the next section, we have done the computational works, where we have plotted the locations of equilibrium points, zero-velocity curves, regions of motion, Poincaré surfaces of section and basins of attraction in different planes (in-plane and out-of-planes). Moreover, we have examined the linear stability of all the equilibrium points and found that all the equilibrium points are unstable.

The mechanism of wrinkling of cotton fabric in a front-loading washer: The effect of mechanical action

In order to understand the impact of mechanical action on the wrinkling of cotton fabrics in a drum washer, fabric movement was observed and a movement index system was developed to characterize the textile motion. Results showed that spinning speed and wash load were the major factors influencing the smoothness of cotton fabrics, with p values of 0.000 and 0.032, respectively. The analysis of fabric movement illustrated that when the wash load increased, the free motion region decreased and the ratio of passive motion region increased, resulting in severe wrinkling of cotton fabric. A regression model was developed to characterize the relationship between fabric movement and smoothness. These findings help the understanding of the mechanism of wrinkling during a drum washer washing.

Motion Maps and Their Applications for Dynamic Object Monitoring

In this paper, dynamic object behavior analysis task is considered. We use basic optical flow to form integral optical flow and use it to separate background and foreground and obtain intensive motion regions. Based on information extracted from integral optical flow, we introduce notion of motion maps and show how it can be used for dynamic object motion analysis. In motion maps, we analyze pixel motions statistically for each frame to obtain quantity of pixels moving toward or away from each position and their comprehensive motion at each position. We then define and compute regional motion indicators to describe motions at regional level. These indicators are further used for analysis of dynamic object behavior. We conduct a set of experiments on real world videos. Experimental results show that motion maps can be effectively used for dynamic object monitoring.

Modeling and recognition of human limbs cooperative interaction based on Random Increased Hybrid Learning Machine

In this paper, we study the identification problem of human limbs synergistic interaction based on the application of natural human-computer interaction. We proposed an identification model of human limbs cooperative interaction based on the Random Increased Hybrid Learning Machine for the unique requirements of natural human-computer interaction applications. The model combines the motion region image, the Hu invariant moment model and the RIHLM. In this paper, the algorithm theory, the model rationality and the implementation of the human motion recognition model based on the RIHLM is described. Finally, by comparing the experimental results, we verified that the model presented in this paper has better robustness, timeliness and accuracy in the application of natural human-computer interaction.

Research on regional clustering and two-stage SVM method for container truck recognition

With large-scale, integrated, intelligence for ports, many ports begin to use intelligent detection systems to make their operations more efficient. The container truck recognition and positioning system is also beginning to apply into container quayside to assist the joint operations between quay cranes and container trucks. However, the traditional vehicle detection by using motion region detection cannot recognize the type of moving object, and the traditional pattern recognition method cannot meet the requirements in real-time operation. In order to solve these problems, an algorithm fused by regional clustering and two-stage SVM classifier is proposed in this paper. The method consists of two phases, which are independently executed in two camera systems on quay cranes. In the first stage, a fast motion regional clustering algorithm is used to detect moving image patches as the truck candidate sub-windows. In the second stage, the container trucks will be recognized in these sub-windows by an optimized two-stage SVM classifier. Compared with existing traditional algorithm, experimental results in container terminal show that the fusion algorithm with regional clustering and two-stage SVM has higher efficiency and better truck recognition performance.

Improved algorithm for calculating electric field in microwave applicators of irregular shapes with elements in translation

Our previous work shows that the use of two time-varying anisotropic layers on the basis of transformation optics can calculate the electric field in microwave applicators of regular shapes with moving elements in translation accurately and efficiently. However, it is difficult to deal with applicators of irregular shapes, which is widely used in practical applications. In this article, we extend this work to the calculation of electric field in applicators of irregular shapes. In the proposed two-dimensional model, the motion region is truncated by rectangular anisotropic coated layers, including four edge layers and four corner layers. In this case, the motion region is independent of applicator shapes. Therefore, the electric field can be calculated equivalently with arbitrary irregular applicator shapes. The results show good accuracy and efficiency, which indicates that the improved method has a good potential for modeling the heating process of practical microwave applicators with elements in translation.

On the existence of libration points in the spatial collinear restricted four-body problem within frame of repulsive Manev potential and variable mass

The present paper deals with the spatial collinear restricted four-body problem within the frame of repulsive Manev potential (−1r+er2),e>0 and variable mass. We have revealed that how the parameters involved due to variable mass of the infinitesimal body influence the locations as well as number of libration points. Moreover, it is observed that the libration points exist only on the coordinate axes. The regions of possible motion are highly influenced by the Manev parameter, parameter occur due to variable mass of the infinitesimal body as well as by the Jacobian constant. Further, it is unveiled that the libration points are unstable for all the involved parameters.

Global dynamics and integrity of a micro-plate pressure sensor

This paper investigates the complex bifurcation scenario of electrically-actuated circular micro-plates subjected to differential pressure. Our analysis deals with the primary, secondary and ultimate saddle-node bifurcation points responsible for the device snap-through and addresses the pressure range in which the robustness of the two main stable configurations is undermined by minor coexisting attractors. By making use of basins of attraction and integrity profiles, safe dynamical regions of motion are evaluated with respect to the applied DC voltage. It is found that period-doubling bifurcations are accountable for a sensible reduction in the dynamical integrity, small variations of the DC voltage largely modify the response of the pressure sensor.