Oscillations Of Body Research Articles

Oscillation of Contemporary Bodies between Biopolitics and Necropolitics

The article examines Tania Bruguera’s works 10,148,451 (2019, Tate Modern, UK) and the three versions of Tatlin’s Whisper #6 (2009 and 2014, Havana; 2015, Tate Modern). Thinking with Achille Mbembe’s work on necropolitics, Lauren Berlant’s on “slow death,” and Michel Foucault’s on biopolitics, Paramana suggests that 10,148,451 addresses the collective subject and critiques contemporary necropolitics, while the versions of Tatlin’s Whisper #6 address individuals as political subjects, and comment on the panoptic gaze and contemporary biopolitics. Through her analysis of these works, Paramana shows how Bruguera’s work is created to comment on the specific political economies in which it is presented, how the perception of the work’s politics differs when presented in different political economies, and the insights therefore the work might offer to them. Paramana argues that Bruguera’s work has often achieved more than local and national governments and that her “symbolic work with activist parameters” is surprisingly more efficacious than her activist work. The article concludes with the insights Bruguera’s work offers for the future of bodies in the 21st century.

APPLICATION OF THE VIBROPNEUMATIC SEPARATOR IN THE CLEANING AND PREPARATION SECTION OF THE CEREALS PROCESSING COMPANY

The development and introduction in the milling industry of new vibrating machines for separating and drying solid particles contributes to the intensification of this difficult technological process. The vibration action allows considerably improving the kinematic parameters – increasing the acceleration and frequency of the working body, reducing the amplitude of the oscillation of the working body compared to existing machines. Cleaning the batch of grains from impurities, sorting their derived products, as well as partially reducing humidity, represent the set of operations, which are carried out with the aim of increasing the quality of the grains in the batch and the derived products. Simultaneously with the removal of impurities, cleaning reduces the volume of products that must be handled, transported and stored, as well as the removal of 1-2% of moisture along the way. In the case of wheat intended for consumption, it is aimed to eliminate impurities as much as possible, which have no food value. The modernized vibropneumatic separator intended for the processing of cereal products, contains a body, mounted on a drum, with a hermetically fixed cover, in which a telescopic connection is placed for cutting the wet product. A working organ is located inside the body, made in the form of a conical sieve with the tip up. The conical sieve is rigidly connected with a vibrating mechanism, and with the bat - by means of elastic elements. Under the action of the vibrating mechanism, the working organ performs a complex spatial movement. Ducts for exhausting the air flow are installed on the circumference of the cover. An inner cone and an outer cone are placed one inside the other under the conical sieve. The device also contains connections for the discharge of the sifted fractions and refuse.

ON THE RECONSTRUCTION OF PRESTRESS FIELDS IN A HOLLOW CYLINDER

The present research is devoted to the development of the theoretical foundations of nondestructive acoustic method for identifying inhomogeneous prestress fields in a hollow cylinder, depending on the probing loading type. A linearized model of steady oscillations of an elastic body in the presence of an inhomogeneous prestress field of arbitrary nature is considered in the standard and weak formulations. On the basis of this model, we formulate a problem for a cantilever-clamped prestressed hollow cylinder that performs steady axisymmetric vibrations under three types of probing loading. A corresponding weak formulation of the problem in the cylindrical coordinate system is presented, in which six independent components of the prestress tensor are taken into account. At that, a case of prestress fields obtained by applying some initial mechanical external static load is considered. In the presence and absence of prestresses of various types, amplitude-frequency dependences are analyzed, and resonant and natural frequencies are found in a wide frequency range. Numerical calculations were carried out using the FEM on a non-uniform grid; mesh refinement is carried out in the vicinity of the boundary points, where the type of boundary conditions changes. Based on the numerical solution of an auxiliary set of direct problems, seven types of prestress fields are constructed, differing in the types of initial loading, most often encountered in practice. To assess the possibility of implementing the procedure for reconstructing prestresses of each of the considered types, a sensitivity analysis was additionally performed, which showed that for some prestress types there are frequencies and types of probing loading for which the presence of prestress is practically not manifested. The sensitivity analysis performed made it possible to implement the optimal method of probing loading when solving the inverse coefficient problem. The statement of the new inverse problem on the restoration of arbitrary inhomogeneous prestress fields in the considered finite hollow cylinder is formulated. When restoring the prestress of a given structure, the inverse problem is reduced to finding a set of parameters from an ill-conditioned algebraic system, which was studied with the help of the A.N. Tikhonov regularization method. Additional data for solving the inverse problem was obtained on the basis of probing both via a single load and via combined probing modes. It has been found that it is most effective to use a combined loading mode and use a sufficiently wide frequency range when selecting sounding frequencies. The results of computational experiments on the reconstruction of six components of the prestress tensor are presented and analyzed, and recommendations are proposed for choosing the optimal modes of acoustic sounding.

Environmental force sensing helps robots traverse cluttered large obstacles

Robots can traverse sparse obstacles by sensing environmental geometry and avoiding contact with obstacles. However, for search and rescue in rubble, environmental monitoring through dense vegetation, and planetary exploration over Martian and lunar rocks, robots must traverse cluttered obstacles as large as themselves by physically interacting with them. Previous work discovered that the forest floor-dwelling discoid cockroach and a sensor-less minimalistic robot can traverse cluttered grass-like beam obstacles of various stiffness by transitioning across different locomotor modes. Yet the animal was better at traversal than the sensor-less robot, likely by sensing forces during obstacle interaction to control its locomotor transitions. Inspired by this, here we demonstrated in simulation that environmental force sensing helps robots traverse cluttered large obstacles. First, we developed a multi-body dynamics simulation and a physics model of the minimalistic robot interacting with beams to estimate beam stiffness from the sensed contact forces. Then, we developed a force feedback strategy for the robot to use the sensed beam stiffness to choose the locomotor mode with a lower mechanical energy cost. With feedforward pushing, the robot was stuck in front of stiff beams if it has a limited force capacity; without force limit, it traversed but suffered a high energy cost. Using obstacle avoidance, the robot traversed beams by avoiding beam contact regardless of beam stiffness, resulting in a high energy cost for flimsy beams. With force feedback, the robot determined beam stiffness, then traversed flimsy beams by pushing them over and stiff beams by rolling through the gap between them with a low energy cost. Stiffness estimation based on force sensing was accurate across varied body oscillation amplitude and frequency and position sensing uncertainty. Mechanical energy cost of traversal increased with sensorimotor delay. Future work should demonstrate cluttered large obstacle traversal using force feedback in a physical robot.

Pressure Pulsatility Links Cardio-Respiratory and Brain Rhythmicity.

This article presents evidence indicating that intracranial pressure (ICP) pulsatility, associated with the heartbeat and breathing, is not just a source of mechanical artefact in electrical recordings, but is "sensed" and plays a role in the brain's information processing. Patch-clamp recording of pressure-activated channels, and detection of Piezo2-protein channel expression in brain neurons, suggest that these channels provide neurons with an intrinsic resonance to ICP pulsatility, which acts to synchronize remote neural networks. Direct measurements in human patients indicate that heartbeat and breathing rhythms generate intracranial forces of tens of millinewtons, exceeding by orders of magnitude the localized forces shown by atomic force microscopy and optical tweezers to activate Piezo channels in isolated neocortical and hippocampal neurons. Additionally, many human touch and proprioceptors, which are also transduced by Piezo channels, show spiking that is phase-locked to heartbeat- and breathing-induced extracranial pressure pulsations. Finally, based on the observation that low-frequency oscillations modulate the phase and amplitude of high-frequency oscillations, body and brain oscillations are proposed to form a single hierarchical system in which the heartbeat is the basic frequency and scaling factor for all other oscillations. Together, these results support the idea that ICP pulsatility may be elemental in modulating the brain's electrical rhythmicity.

Practical implementation and experimental testing of control system for vibratory lapping-polishing machine

Vibratory technological machines are widely implemented in various branches of industrial, manufacturing, and mechanical engineering. Particularly, such equipment can be effectively used while conducting finishing technological operations, e.g., lapping and polishing of different machine parts. The present paper is focused on developing the control system for the novel design of a vibratory lapping-polishing machine driven by six solenoids. The main purpose consists in providing the circular trajectory of the working member and ensuring the machining uniformity at each point of the surface being treated. In such a case, it is proposed to actuate the solenoids with the specified time shift depending on the forced frequency needed to be provided. The duration of the signal actuating the solenoid is equal to one-sixth of the total duration of a cycle (period) of the working body oscillation. The corresponding control approach is developed and simulated in the Tinkercad application, while the control system is designed based on the Arduino software and hardware. In addition, the laboratory prototype of the vibratory lapping-polishing machine and the corresponding control system are implemented in practice. The performed experimental investigations substantiate the possibilities of generating the circular oscillations of the working member of the vibratory lapping-polishing machine. The obtained results may be useful for engineers and technologists dealing with control systems of various vibratory technological equipment based on electromagnetic and solenoid-type drives.

Dynamic Responses of 8-DoF Vehicle with Active Suspension: Fuzzy-PID Control

The driving smoothness of vehicles is heavily influenced by their suspension system, and implementing active suspension control can effectively minimize the vibration movement of the vehicle and ensure a comfortable driving experience. An 8-DoF active suspension model of the full vehicle is established, and a fuzzy-PID controller is designed to autonomously regulate the parameters of the PID controller. Using the MATLAB/Simulink environment, a simulation model for suspension is created, and the vibration characteristics of passive, PID control, and fuzzy-PID control suspensions are compared with the help of the continuous crossing road hump model and C-level road model as road inputs. The results show that the utilization of fuzzy-PID control considerably diminishes the vertical, pitch, and roll oscillations of the suspension body and modifies the suspension dynamic deflection and tire dynamic load in contrast to the other two scenarios, thus enhancing ride comfort. Fuzzy-PID control led to a decrease of approximately 40% in acceleration, 25% in suspension workspace, and 30% in tire deflection compared to passive suspension. In addition, the reduction in acceleration is about 20%, the reduction in suspension workspace is approximately 10%, and the reduction in tire deflection is about 15% compared to the PID control suspension system.

The Orbital Stability Analysis of Pendulum Oscillations of a Heavy Rigid Body with a Fixed Point Under the Goriachev–Chaplygin Condition

The Orbital Stability Analysis of Pendulum Oscillations of a Heavy Rigid Body with a Fixed Point Under the Goriachev–Chaplygin Condition

Study of Self-Excited Pitch Oscillations of Conical-Spherical Body at Mach Number M = 1.75 and Two Moments of Inertia

Tests of a conical-spherical body in a supersonic wind tunnel were carried out on a free oscillation installation along the pitch angle at a Mach number M = 1.75 and two moments of inertia of the body relative to the axis of rotation. For a body with a large moment of inertia, self-oscillations with the amplitude of ca. 10 deg were obtained. For the first time, the phenomenon of degeneration of self-oscillations for a body with a smaller moment of inertia has been discovered. An attempt was made to model the phenomenon using an ordinary linear differential equation of the first order

Simple Mathematical Models for the Dynamics Of Spacecraft With Deployed Solar Panels

Most present day spacecrafts have large interconnected deployed solar panels having very low natural frequencies. The control torque applied to maneuver the spacecraft sets up transient oscillations in the spacecraft. The present work studies the nature of these interactions. The spacecraft in orbit can be modeled as a free rigid mass with flexible elements attached to it. It is shown that the oscillations of the spacecraft body are characterized by the dynamic characteristics of the flexible panel even if the mass and mass moment of inertia of the body is signifcantly higher than that of the flexible panels. A simple model consisting of an Euler-Bernoulli beam attached to a mass can represents such a system. The infuence of various parameters of the Euler-Bernoulli beam and the rigid element on the disturbances caused in the rigid element are investigated. The characteristics are determined for a step and also for a torque input. The responses are obtained in terms of nondimensionalised quantities. It is demonstrated that using the simple model developed the responses of spacecraft body can be easily obtained.

Improving the stability and handling of tractors when towing trailers and coupled units

BACKGROUND: Currently, almost all agricultural work is performed using tractors. As the transport speed of a tractor train increases, the amplitude of lateral and horizontal oscillations of its coupled units emerges and increases. At certain velocities, these oscillations become so large that they can lead to a rollover, in addition, shock loads occur in coupling devices, which make it difficult to handle a tractor train. The traditional method to prevent this is the velocity limit, which does not guarantee a positive result.
 AIMS: Development of methods to improve stability, handling and safety of wheeled tractor trains by reducing the galloping and yawing of a truck tractor when towing heavy loads.
 METHODS: The following options of the design of the system for countering the occurrence of self-oscillations in the design of a wheeled tractor train ensuring a reduction in the level of self-oscillations, increasing the stability, handling and safety of the tractor train have been proposed: the coupling device equipped with hydraulic damping devices operating at longitudinal and lateral folding; the control system for the individual traction electric drive of a truck tractor preventing the loss of wheel grip with the ground surface; the combined use of the control system for the individual traction electric drive of a truck tractor and the coupling device equipped with hydraulic damping devices; the combined use of the coupling device equipped with hydraulic damping devices and a steering correction system.
 RESULTS: With use of simulation modeling methods, it has been established that the coupling device equipped with hydraulic damping devices adjustable by the folding angle of the tractor train and by the yaw angle oscillations of a truck tractor body should be recognized as the most acceptable and effective system for reducing self-oscillations of a wheeled tractor train at the current state of the art.
 CONCLUSIONS: The practical value of the study lies in the possibility of using the proposed methods to eliminate the risk of self-oscillating processes in the design of promising types of agricultural machinery.

Serpentine motion of a trimaran robot

An aquatic robot is proposed that moves due to the motion of an internal flywheel. The body of the robot represents a trimaran that consists of a capsule and three floats rigidly attached to it. The floats are submerged into the water and ensure that the capsule is afloat. The horizontal cross-section of each float has the shape of an airfoil. The body moves in a horizontal plane. The rotation axis of the internal flywheel is vertical. The control system makes the flywheel to oscillate, which results in oscillations of the robot body together with the floats. It is known that, when an airfoil oscillates in pitch in fluid, a thrust force is produced. As a result, the center of mass of the body moves along a serpentine trajectory. The goal of the study is to describe the effect of geometrical parameters of the robot and coefficients of the control law on the average speed of propulsion. A quasi-steady model is used to describe the hydrodynamic forces acting upon the trimaran. In order to take into account non-steady effects, added masses are considered. This approach allows for describing the robot dynamics with the ODE system. Numerical simulation of the system behavior is performed. Attracting periodic solutions are found using the relaxation method. Parametric analysis of such solutions is performed. A laboratory model is manufactured, and a series of experiments is performed. It is shown theoretically and experimentally that the speed of propulsion of the robot depends non-monotonically on the control frequency.

Transcranial direct current stimulation suggests not improving postural control during adapted tandem position in people with Parkinson's disease: A pilot study

BackgroundBalance impairments in people with Parkinson's disease (PD) demonstrated mainly in challenging postural tasks, such as increased body oscillation may be attributed to the deficits in the brain structures functionality involved in postural control (e.g., motor cortex, midbrain, and brainstem). Although promising results, the effect of transcranial direct current stimulation (tDCS) on postural control in people with PD is unclear, especially in objective measures such as the center of pressure (CoP) parameters. Thus, we analyzed the effects of a single session of tDCS on the CoP parameters during the adapted tandem position in people with PD. MethodsNineteen people with PD participated in this crossover, randomized, and double-blind study. Anodal tDCS was applied over the primary motor cortex in two conditions of stimulation (2 mA/active and sham) on two different days for 20 min immediately before the postural control evaluation. Participants remained standing in an adapted tandem position for the postural control assessment for 30 s (three trials). CoP parameters were acquired by a force plate. ResultsNo significant differences were demonstrated between stimulation conditions (p-value range = 0.15–0.89). ConclusionsOur results suggested that a single session of tDCS with 2 mA does not improve the postural control of people with PD during adapted tandem.

On the effect of vibrational capture of rotation of an unbalanced rotor

The dynamics of an unbalanced rotor with a vibrating suspension axis and driven by an asynchronous electric motor of limited power is considered. Stationary (near stationary) modes of rotation of the rotor with a frequency equal to the vibration frequency of the axis are investigated. An explanation of the phenomenon of vibrational capture of rotation of an unbalanced rotor is given. The proposed mechanical interpretation of the effect allows deeper understanding of the classical results and conclusions. The obtained condition for the existence of a stationary mode allows us to estimate the frequency capture interval of the rotor. The case when the mode of vibration capture of rotation is not set is considered. For such a case, an expression for the vibrational moment is obtained, as well as an equation for slow motions. Attention is drawn to the possibility of occurrence in the considered modes of motion of slow (relative to the rotation frequency) rotor oscillations with sufficiently large amplitudes. It is demonstrated that the vibrational capture mode has the property of self-regulation; allows to stabilize the rotation frequency of an unbalanced rotor during load oscillations. Attention is drawn to the fact that in this mode of motion, there is certainly a transfer of energy either from the source of vibration to the rotor, or vice versa. The Sommerfeld effect in an oscillatory system with an inertial vibration exciter is represented by vibration capture of rotation of the vibration exciter by resonant oscillations of the carrier body. The theoretical results are confirmed by numerical modelling.

Excitation of an extreme wave by standing current

The statistics suggest that extreme waves cause more damage in shallow waters and at the coast than in the deep sea. In the linear theory of the formation of extreme waves, their existence is interpreted as a local superposition of surface monochromatic waves. The event of excitation of extreme waves can be understood as an increase in natural oscillations of the water basin. The conditions for the excitation and sustaining of natural oscillations are the proximity of the periods of exciting traveling waves to the period of traveling waves and the speed of movement of the exciting current to the phase speed of propagation of traveling waves of the reservoir. Examples of stimulating natural oscillations are presented. We determined the range of expected periods of natural oscillations, which range from 30 seconds to 24 hours. Synchronously and in common-mode with the oscillations of standing waves between their antinodes, a "standing" current occurs with a measured speed of up to 11 km/h. We presented a hypothesis about the possibility of stimulating natural oscillations of water bodies by a standing current, which changes its direction due to the movement of the water surface from the trough of the wave to its crest, and back. A model of stimulating oscillations by the waves with a constant period and currents with constant and variable speeds has been developed.

The 'Postural Rhythm' of the Ground Reaction Force during Upright Stance and Its Conversion to Body Sway-The Effect of Vision, Support Surface and Adaptation to Repeated Trials.

The ground reaction force (GRF) recorded by a platform when a person stands upright lies at the interface between the neural networks controlling stance and the body sway deduced from centre of pressure (CoP) displacement. It can be decomposed into vertical (VGRF) and horizontal (HGRF) vectors. Few studies have addressed the modulation of the GRFs by the sensory conditions and their relationship with body sway. We reconsidered the features of the GRFs oscillations in healthy young subjects (n = 24) standing for 90 s, with the aim of characterising the possible effects of vision, support surface and adaptation to repeated trials, and the correspondence between HGRF and CoP time-series. We compared the frequency spectra of these variables with eyes open or closed on solid support surface (EOS, ECS) and on foam (EOF, ECF). All stance trials were repeated in a sequence of eight. Conditions were randomised across different days. The oscillations of the VGRF, HGRF and CoP differed between each other, as per the dominant frequency of their spectra (around 4 Hz, 0.8 Hz and <0.4 Hz, respectively) featuring a low-pass filter effect from VGRF to HGRF to CoP. GRF frequencies hardly changed as a function of the experimental conditions, including adaptation. CoP frequencies diminished to <0.2 Hz when vision was available on hard support surface. Amplitudes of both GRFs and CoP oscillations decreased in the order ECF > EOF > ECS ≈ EOS. Adaptation had no effect except in ECF condition. Specific rhythms of the GRFs do not transfer to the CoP frequency, whereas the magnitude of the forces acting on the ground ultimately determines body sway. The discrepancies in the time-series of the HGRF and CoP oscillations confirm that the body's oscillation mode cannot be dictated by the inverted pendulum model in any experimental conditions. The findings emphasise the robustness of the VGRF "postural rhythm" and its correspondence with the cortical theta rhythm, shed new insight on current principles of balance control and on understanding of upright stance in healthy and elderly people as well as on injury prevention and rehabilitation.

MODELING OF A CONTROLLED ELECTROMAGNETIC VIBRATION DRIVE WITH A VARIABLE RESONANT FREQUENCY

The technology for the production of high-quality concrete products includes the vibration of the concrete mixture at various frequencies. For this, an electromagnetic vibration drive can be used, which has high reliability, durability and controllability. For its effective application, it is necessary to adjust the resonance frequency of the oscillating system in order to ensure the near-resonance mode of operation at different frequencies. This is possible by using devices with adjustable stiffness, in particular, controlled dynamic vibration absorbers with nonlinear elastic elements. In the article the electromagnetic, electromechanical, mechanical, and energy processes in a controlled vibration system, which includes an electromagnetic vibrator and a vibration absorber with conical springs, the stiffness of which is regulated by compression using a press, have been investigated. Using the circle-field method, a mathematical and simulation model of electromagnetic and electromechanical processes in the vibrator has been developed. For this purpose, numerical calculations of the magnetic field in the vibrator have been performed and, based on the obtained results, the functional dependences between the electromagnetic force, magnetic flux, magnetomotive force and the size of the air gap have been determined. A model of the mechanics of the oscillating system, processes in the vibration absorber press drive and processes in the control system has been also developed. The built simulation models were combined into a general model in the Simulink environment, by means of which the time diagrams of the processes have been obtained. The modeling results show that the system provides a smooth transition from one vibration frequency to another while maintaining the specified amplitude of the working body oscillations and near-resonance mode with high energy efficiency. References 12, figures 10, tables 3.

Method of calculating the influence of the suppression system on the autonomy of an armored combat vehicle

A method of calculating the effect of vibrations of the sprung body and the operation of the suspension system of an armored combat vehicle on its autonomy has been developed. One of the main indicators of autonomy is the power reserve, which depends on the specific fuel consumption. In the process of moving over bumps, a significant part of the power plant's energy, and accordingly fuel, is spent on the occurrence of vibrations of the sprung body of the machine and its unsprung masses. Then the energy of these vibrations is converted into heat in the damping devices of the chassis. In difficult road conditions, on real tracks, these losses average 10...15% of power plant power. In resonant modes, when moving along a harmonic profile of irregularities, they can reach 30%. Calculation and reduction of these costs will increase the autonomy of the armored combat vehicle.&#x0D; The methodology is based on the calculation of the energy balance of the longitudinal, angular and vertical vibrations of the sprung body of the machine and the vibrations of its unsprung masses, the deformation energies of the elastic elements of the suspension, the rubber hinges of the guide devices and tires, as well as the energies absorbed by the suspension damping devices, its rubber hinges and tires. Depending on this balance, there is either an increase in the load on the power plant and, accordingly, an increase in fuel consumption, or it decreases and the energy of the suspension system becomes the driving force. To calculate the oscillations of the sprung body and components of the energy balance, it is necessary to use a mathematical model of the movement of an armored combat vehicle over bumps. All the necessary parameters of the machine, a deterministic road profile of bumps and a high-speed driving mode are set. Amplitudes and velocities of longitudinal angular and vertical oscillations of the sprung body and oscillations of unsprung masses are calculated from these input data. For each suspension, its kinematics, twisting angles of torsions, forces in damping devices and the amount of movement of their working bodies and deformation of rubber joints and tires are calculated. Next, the magnitude and sign of the change in the total energy of the sprung body and the sprung system at each moment of time is determined. Based on the additional energy calculated using the efficiency coefficients of the engine and transmission, the additional power supplied by the power plant and, accordingly, additional fuel consumption are determined.&#x0D; Thus, it is possible to evaluate and compare with each other the reduction in the range of the armored combat vehicle, which is caused by the fluctuations of the sprung body and the operation of the suspension system, depending on the type and characteristics of the suspension, when driving in specific road conditions, at the given speed modes. With the help of the developed methodology, it is possible to carry out structural and parametric optimization of the suspension kinematics and the characteristics of its elastic elements and damping devices, in order to reduce fuel consumption and increase the autonomy of the armored combat vehicle. This technique will be useful in assessing the expediency of using the energy recovery system of the suspension system, depending on the purpose and conditions of operation of combat armored vehicles.

Model order reduction for seismic waveform modelling: inspiration from normal modes

SUMMARY The computational cost of full waveform simulation in seismological contexts is known to be expensive and generally requires large clusters of computers working in parallel. Although there have been many methods proposed over recent years to reduce this burden, in this work, we focus on a particular method called model order reduction (MOR) whereby a full waveform system of equations is projected onto a lower dimensional space to reduce computational and memory requirements at the cost of introducing approximation errors. In this paper, inspired by normal mode (NM) theory, we use the eigenmodes of the seismic wave equation to span this lower dimensional space. From this we argue that NM theory can be seen as an early form of MOR. Using this as inspiration, we demonstrate how free body oscillations and a form of Petrov–Galerkin projection can be applied in regional scale problems utilizing recent advanced eigensolvers to create a MOR scheme. We also demonstrate how this can be applied to inverse problems. We further conjecture that MOR will have an important role to play in future full waveform applications, particularly those of a time-critical nature such as seismic hazard monitoring.

Tracking and Characterizing Spatiotemporal and Three-Dimensional Locomotive Behaviors of Individual Broilers in the Three-Point Gait-Scoring System.

Gait scoring is a useful measure for evaluating broiler production efficiency, welfare status, bone quality, and physiology. The research objective was to track and characterize spatiotemporal and three-dimensional locomotive behaviors of individual broilers with known gait scores by jointly using deep-learning algorithms, depth sensing, and image processing. Ross 708 broilers were placed on a platform specifically designed for gait scoring and manually categorized into one of three numerical scores. Normal and depth cameras were installed on the ceiling to capture top-view videos and images. Four birds from each of the three gait-score categories were randomly selected out of 70 total birds scored for video analysis. Bird moving trajectories and 16 locomotive-behavior metrics were extracted and analyzed via the developed deep-learning models. The trained model gained 100% accuracy and 3.62 ± 2.71 mm root-mean-square error for tracking and estimating a key point on the broiler back, indicating precise recognition performance. Broilers with lower gait scores (less difficulty walking) exhibited more obvious lateral body oscillation patterns, moved significantly or numerically faster, and covered more distance in each movement event than those with higher gait scores. In conclusion, the proposed method had acceptable performance for tracking broilers and was found to be a useful tool for characterizing individual broiler gait scores by differentiating between selected spatiotemporal and three-dimensional locomotive behaviors.