Types Of Motion Research Articles

Effectiveness of different toothbrushing patterns among schoolchildren in an urban area of Argentina.

To identify toothbrushing patterns among schoolchildren with no prior dental hygiene training and associate them with effectiveness for eliminating dental biofilm. Eight calibrated dentists assessed dental biofilm, toothbrushing procedure and dental status and registered: grip, bristle angle with respect to tooth, type of movement, surfaces brushed, simultaneous brushing of both jaws, including all six sextants and duration of brushing dental biofilm before and after brushing was determined in 944 children. Frequency distribution was calculated for nominal variables and central tendency and dispersion for quantitative variables of the toothbrushing procedure. Effectiveness was evaluated in 236 children by calculating differences between biofilm levels before and after brushing using Student's test. A cutoff value was established for the difference in reductions in biofilm levels by means of an ROC curve. The variables including all 6 sextants and bristle angle showed positive association with biofilm reduction. The cutoff point for biofilm reduction for including all 6 sextants was 66.85% (OR 6.4 [3.6-11.38]). The cutoff value for biofilm reduction for bristle angle was 68.35% (OR 3.2 [1.83-5.8]). The variables associated with biofilm reduction can be used to optimize the modality of future educational interventions in schoolchildren.

Recognition of Human Lower Limb Motion and Muscle Fatigue Status Using a Wearable FES-sEMG System.

Functional electrical stimulation (FES) devices are widely employed for clinical treatment, rehabilitation, and sports training. However, existing FES devices are inadequate in terms of wearability and cannot recognize a user's intention to move or muscle fatigue. These issues impede the user's ability to incorporate FES devices into their daily life. In response to these issues, this paper introduces a novel wearable FES system based on customized textile electrodes. The system is driven by surface electromyography (sEMG) movement intention. A parallel structured deep learning model based on a wearable FES device is used, which enables the identification of both the type of motion and muscle fatigue status without being affected by electrical stimulation. Five subjects took part in an experiment to test the proposed system, and the results showed that our method achieved a high level of accuracy for lower limb motion recognition and muscle fatigue status detection. The preliminary results presented here prove the effectiveness of the novel wearable FES system in terms of recognizing lower limb motions and muscle fatigue status.

Evaluating the Injection of Platelet-Rich Plasma on Second Lower Molars Protraction: A Randomized Controlled Clinical Trial.

Background The use of platelet-rich plasma (PRP) in dentistry was entered several decades ago, yet its clinical use in orthodontics still requires further investigation. The aim of this study was to evaluate the possible effects of local injection of PRP on the rate and typeof mandibular second molar protractionmovement compared with the comparator (no PRP) group. Material and methods Eighteen patients aged between 17 and 25 years were randomly allocated in a split-mouth study design to receive PRP injections on one sideimmediately before the start of molar protraction (PRP group), while the other side received only saline solution (comparator group). Eligibility criteria included bilaterally extracted mandibular first molars casesand indicated mandibular second molars protraction. The primary outcome of the study consisted of measuring the rate of molar protraction from the beginning of protraction (T0) to the end of the seventh month (TF), using a digital gauge. The secondary outcome included measuring the typeof second molar protraction movement between T0 and TFby lateral cephalometric images. Randomization of the intervention side was performed by picking out opaque sealed envelopes. The blinding of the principal investigator was impossible but blinding of the patient was achieved by injection of saline. Analyses were done using paired samples T-test to compare the changes in all variables between T0 and TF. The level of significance was taken at a P-value < 0.05. Results No significant difference was detected between the PRP and comparator groups in the rate of second lower molar protraction during seven months (0.56±0.07 mm per month in the comparator group, whereas, was 0.6±0.11 mm per month in the PRP group). Molar protraction parameters in both groups showed second lower molars moving by controlled tipping closer to bodily movement (Root Movement:Crown Movement≈0.8). Conclusions Platelet-rich plasma (PRP) is ineffective in accelerating the rate of orthodontic tooth movement (OTM) during molar protraction, and it has no effect on the type of tooth movement. In addition, the mechanics that we used (6 mm power arm in combination with miniscrews) are effective in mandibular second molar protraction by controlled tipping closer to bodily movement.

Multiscale modeling of dislocation-mediated plasticity of refractory high entropy alloys

Refractory high entropy alloys (RHEAs) have drawn growing attention due to their remarkable strength retention at high temperatures. Understanding dislocation mobility is vital for optimizing high-temperature properties and ambient temperature ductility of RHEAs. Nevertheless, fundamental questions persist regarding the variability of dislocation motion in the rugged energy landscape and the effective activation barrier for specific mechanisms, such as kink-pair nucleation and kink migration. Here we perform systematic atomistic simulations and conduct statistical analysis to obtain the effective activation barriers for the mechanisms underlying various types of dislocation motion in a typical RHEA, NbMoTaW. Moreover, a stochastic line tension model is developed to calculate the activation barrier with substantially reduced computational costs. By incorporating the effective activation barriers into the crystal plasticity model, a multiscale simulation framework for predicting the mechanical properties of RHEAs is established. The ambient temperature yield strength of NbMoTaW is well-predicted by the kink-pair nucleation mechanism of screw dislocations, while the strengthening originating from screw dislocations does not predominate at high temperatures. Our work provides a robust foundation for atomistic studies of effective dislocation behaviors in random solution solids, elucidating the intricate relationship between microscopic mechanisms and macroscopic properties.

Micro-Doppler based Human Activity Recognition using ABOA based Dual Spatial Convolution with Gated Recurrent Unit

The through-wall capability, device-free detection of radar-based human activity recognition are drawing a lot of interest from both academics and industry. The majority of radar-based systems do not yet combine signal analysis and feature extraction in the frequency domain and the time domain. Applications like smart homes, assisted living, and monitoring rely on human identification and activity recognition (HIAR). Radar has a number of advantages over other sensing modalities, such as the ability to shield users' privacy and conduct contactless sensing. The article introduces a new human tracking system that uses radar and a classifier called Dual Spatial Convolution Gated Recurrent Unit (DSC-GRU) to identify the subject and their behavior. The system follows the person and identifies the type of motion whenever it detects movement. One important feature is the integration of the GRU with the DSC unit, which allows the model to simultaneously capture the spatiotemporal dependence. Present prediction models just take into account spatial features that are immediately adjacent to each other, disregarding or just superimposing global spatial features when taking spatial correlation into account. A new dependency graph is created by calculating the correlation among nodes using the correlation coefficient; this graph represents the global spatial dependence, while the classic static graph represents the neighboring spatial dependence in the DSC unit. The DSC unit goes a step further by using a modified gated mechanism to quantify the various contributions of both local and global spatial correlation. While previous models performed worse, the suggested model outperformed them with an accuracy of 99.45 percent and a precision of 97.15 percent.

Animating Cartographic Meaning: Unveiling the Impact of Pictorial Symbol Motion Speed in Preattentive Processing

The primary objective of this study is to assess how the motion of dynamic point symbols impacts preattentive processing on a map. Specifically, it involves identifying the motion velocity parameters for cartographic animated pictorial symbols that contribute to the preattentive perception of the target symbols. We created five pictorial symbols, each accompanied by a unique animation tailored to convey the meaning associated with each symbol. The animation dynamics of symbols on the administrative map were distributed across arithmetic, logarithmic, and exponential scales. Eye-tracking technology was utilized to explain the user’s visual attention. The key findings reveal that, although movement does not uniformly hold the same designation in cartographic communication, it could guide user attention to identify the value peaks in quantitative map visualization. Motion velocity enhances the salience of animated symbols, making them stand out, not only against static elements but also against other animated distractors. Additionally, motion distributions between symbol classes based on exponential or arithmetic scales were identified as the most successful. Nevertheless, certain types of motion, such as rotational, do not perform well with pictorial symbols, even on the most effective motion distribution scale.

Investigating the Relative Contributions of Unexpected Vection and Postural Instability to VR Cybersickness

This study tested unexpected vection and postural instability accounts of cybersickness by having 30 participants play a commercial virtual reality (VR) simulation (“Mission-ISS”), while wearing head-mounted displays (HMD) for up to 14 minutes, or until the first symptoms of sickness. Of these participants, 23 reported symptoms, while 7 did not. We found that the likelihood and severity of cybersickness increased when the vection experienced was unexpected. Spontaneous standing sway before entering VR was also found to differ depending on whether the participant became sick or remained well. In addition, the severity of their sickness appeared to be related to changes in their sway during VR. When these vection and sway-based predictors were examined together, unexpected vection emerged as the strongest predictor of cybersickness. Taken together with the findings of recent studies, the research shows that unexpected vection predicts experiences of cybersickness across a variety of different virtual environments, virtual navigation methods and types of simulated movement.

Assessment of Subject Head Motion in Diffusion MRI.

Subject head motion during the acquisition of diffusion-weighted imaging (DWI) of the brain induces artifacts and affects image quality. Information about the frequency and extent of motion could reveal which aspects of motion correction are most necessary. Therefore, we investigate the extent of translation and rotation among participants, and how the motion changes during the scan acquisition. We analyze 5,380 DWI scans from 1,034 participants. We measure the rotations and translations in the sagittal, coronal and transverse planes needed to align the volumes to the first and previous volumes, as well as the displacement. The different types of motion are compared with each other and compared over time. The largest rotation (per minute) is around the right - left axis (median 0.378 °/min, range 0.000 - 11.466°) and the largest translation (per minute) is along the anterior - posterior axis (median 1.867 mm/min, range 0.000 - 10.944 mm). We additionally observe that spikes in movement occur at the beginning of the scan, particularly in anterior - posterior translation. The results show that all scans are affected by subtle head motion, which may impact subsequent image analysis.

Research on the motion characteristics of the opening process of double joint folding wings

The folding wing mechanism is a system developed for the miniaturization of missile wings to facilitate box (cylinder) storage, transportation, and launching, saving the storage and transportation space of the missile and improving the combat capability of the weapon system. In order to solve the stability problem of the dynamic opening process of wings during missile flight, a theoretical model of a double joint folding wing is proposed. Based on dynamic theory, this paper studies the dynamic process of the folding wing system undergoing rotational opening motion under different initial forces. The influence of the initial angular velocity required for folding wing deployment on the deployment process is analyzed through structural model simulation. Finally, the effect of the folding wing opening action on the flight motion of the full missile is studied, and the dynamic opening process of the folding wing system is simulated by physical experiments. The research results show that the opening motion of the folding wing is sensitive to the initial conditions; during the deformation process, a change in motion type was observed, and the aeroelastic response at certain folding angles may exhibit different motion types. The main impact on the flight motion of the full missile is the change in the aerodynamic force of the missile.

Seismic response of a ground-bridge structure system in horizontal and inclined liquefiable site to near-fault pulse-like ground motions

Previous earthquake events have indicated that bridge structures are more vulnerable to severe damage when subjected to near-fault pulse-like (NF-P) ground motions. Structural seismic damage will be exacerbated when bridges are located in liquefiable site. Meanwhile, the seismic response of bridges located in inclined liquefiable site is different from that of bridges in horizontal liquefiable site. This study focuses on exploring the seismic response of a ground-bridge structure system located in horizontal and inclined liquefiable site to the NF-P ground motions. The seismic response of the whole system to the near-fault non-pulse-like (NF-NP) and far-field (FF) ground motions is studied for comparison. Two three-dimensional (3D) finite element (FE) models of the ground-structure system considering soil-pile interaction are developed. They are associated with the horizontal and inclined liquefiable site, respectively. The seismic responses of the ground-bridge structure system to the three different types of ground motions (i.e., NF-P, NF-NP and FF) are comprehensively evaluated from two perspectives. On the one hand, the seismic time history responses of the ground-bridge structure system under single representative ground motion are comprehensively assessed. On the other hand, the average responses of the ground-bridge structure system under multiple types of ground motions are explored. The results reveal that in contrast to the NF-NP and FF ground motions, the NF-P ground motions have more significant effect on various responses of the ground-bridge structure system. In addition, compared to the bridge in horizontal liquefiable site, the bridge in inclined liquefiable site exhibits larger seismic responses. Therefore, the velocity pulse effect of the NF-P ground motions and the liquefaction effect of the inclined site need to be emphasized in structural seismic design.

Live vs video interaction: sensorimotor and visual cortical oscillations during action observation.

Increasingly, in the field of communication, education, and business, people are switching to video interaction, and interlocutors frequently complain that the perception of nonverbal information and concentration suffer. We investigated this issue by analyzing electroencephalogram (EEG) oscillations of the sensorimotor (mu rhythm) and visual (alpha rhythm) cortex of the brain in an experiment with action observation live and on video. The mu rhythm reflects the activity of the mirror neuron system, and the occipital alpha rhythm shows the level of visual attention. We used 32-channel EEG recorded during live and video action observation in 83 healthy volunteers. The ICA method was used for selecting the mu- and alpha-components; the Fourier Transform was used to calculate the suppression index relative to the baseline (stationary demonstrator) of the rhythms. The main range of the mu rhythm was indeed sensitive to social movement and was highly dependent on the conditions of interaction-live or video. The upper mu-range appeared to be less sensitive to the conditions, but more sensitive to different movements. The alpha rhythm did not depend on the type of movement; however, a live performance initially caused a stronger concentration of visual attention. Thus, subtle social and nonverbal perceptions may suffer in remote video interactions.

Audiovisual integration of rhythm in musicians and dancers.

Music training is associated with better beat processing in the auditory modality. However, it is unknown how rhythmic training that emphasizes visual rhythms, such as dance training, might affect beat processing, nor whether training effects in general are modality specific. Here we examined how music and dance training interacted with modality during audiovisual integration and synchronization to auditory and visual isochronous sequences. In two experiments, musicians, dancers, and controls completed an audiovisual integration task and an audiovisual target-distractor synchronization task using dynamic visual stimuli (a bouncing figure). The groups performed similarly on the audiovisual integration tasks (Experiments 1 and 2). However, in the finger-tapping synchronization task (Experiment 1), musicians were more influenced by auditory distractors when synchronizing to visual sequences, while dancers were more influenced by visual distractors when synchronizing to auditory sequences. When participants synchronized with whole-body movements instead of finger-tapping (Experiment 2), all groups were more influenced by the visual distractor than the auditory distractor. Taken together, this study highlights how training is associated with audiovisual processing, and how different types of visual rhythmic stimuli and different movements alter beat perception and production outcome measures. Implications for the modality appropriateness hypothesis are discussed.

Can esthetically pleasing aligners change the root morphologies? – A narrative review

Background: The occurrence of root resorption (RR) is an unavoidable result of orthodontic treatment. Finding a straightforward approach to its prevention remains a challenge. It is a tragic occurrence when radiographically detected, even though it is rarely severe. The application of force starts a sequence of biological mechanisms. Although we are well aware of how and when it is provoked, we are unable to foresee what will happen in the end. In the past few years, clear aligner therapy has become very popular. Although not much data has been established describing RR after this treatment. Aim: The following review determines the effect of aligner therapy on the resorption of roots leading to the shortening of root length. Methods: Research publications were searched on search engines such as Scopus, PubMed, and Google Scholar using terms such as “RR,” “risk factors of RR” and “effects of clear aligner therapy on RR.” These publications were then collected. Results: For this review, 30 articles were collected and further used to formulate this review. Conclusion: (1) Most affected teeth were the maxillary central and lateral incisors post aligner therapy. (2) Multiple factors that influenced RR were gender, malocclusion, the severity of crowding, type of tooth movement, and close approximation of root toward the cortical plate (3) Clear aligner therapy is comparable to LightForce fixed orthodontics appliances but surpasses heavy-force orthodontic appliances in the terms of the risk associated with developing RR.

English translation of Giesekus's famous article on flows with constant velocity gradient and the motion of particles suspended therein. Part I. Spatial flows

Within the framework of a statistical rheology of suspensions, emulsions, and solutions, it is important to obtain an overview of the total set of flows with a constant velocity gradient. Therefore, the solutions of the differential equations of such flows are given and discussed especially with respect to the influence of the deformation and rotation parts of the velocity gradient. Subsequently, the motion of rigid particles in these flows is analyzed. Both the flow types themselves and the types of motion of the suspended particles can be divided into two broad classes. Among those with predominant deformation influence, we have hyperbolic–parabolic flows as well as a setting of the particles in fixed directions. Among those with predominant rotational influence, we have elliptical–spiral flows as well as a non-uniform orbital motion of the particles. The change from one place of motion to the other depends not only on the shape of the flow but also on the shape of the particles. Deformation becomes stronger as the form anisotropy of the particles increase.

The Impact of a Movement Type on Tribological Properties of AlTiN Coating Deposited on HS6-5-2C Steel

The Impact of a Movement Type on Tribological Properties of AlTiN Coating Deposited on HS6-5-2C Steel

On the motion stabilization of a three-link robotic manipulator with incomplete measurement

Abstract. This paper considers a mathematical model of a manipulator which consists of a vertical column, two links, connected to it in series, and a gripper with a load. The column resting on a fixed base can rotate around its vertical axis. The links are connected by cylindrical hinges allowing them to rotate in the same vertical plane. The column and the links are modeled as rigid bodies with the links having unequal principal moments of inertia. The position of the manipulator in space is determined by three rotation angles of the column and the links. The manipulator can have several types of steady-state program movements. When gravitational torques are compensated by control torques applied in the cylindrical hinges, the manipulator has a program equilibrium position. The manipulator can also have a program motion when the column rotates at a given constant angular velocity, and the links have given relative equilibrium positions in their plane. The stabilization problem of manipulator motion is investigated by means of control torques with feedback when only the rotation angles of the column and links are measured. The problem posed is solved in the form of a nonlinear proportional-integral controller taking into account the cylindrical phase space of the manipulator's mathematical model. The solution includes construction of a Lyapunov functional with a semi-definite derivative and application of the corresponding theorems on the asymptotic stability of non-autonomous functional differential retarded-type equations. The obtained conditions for the program motion stabilization are robust with respect to the mass-inertial parameters of the manipulator. The numerical simulation results demonstrate global attraction to its given position in cylindrical phase space.

Design and Analysis of a Lunar Crewed Vehicle With a Novel Versatile Compliant Suspension Mechanism

Abstract A lunar crewed vehicle (LCV) with improved maneuverability, mobility, and ride comfort is required for astronauts to conduct long-range scientific investigations and resource utilization on the Moon’s surface. This paper concentrates on designing a novel multi-functional compliant suspension for LCV to improve the above-mentioned performance. First, based on the requirement of high-speed traversing on the rough Lunar terrain, the required type of suspension motion is identified and the demanded suspension mechanism is obtained through structural evolution. Then, the kinematic analysis of the proposed suspension mechanism is conducted, and the steering kinematic model of the whole vehicle is established. A compliance analysis is completed, taking into account the actual design characteristics of the suspension mechanism. A multi-degrees-of-freedom dynamics model of the vehicle is developed, considering both wheel–ground separation and the deformation of wheels and soil. Simulations are conducted to verify full vehicle performance with the proposed suspension, and the results reveal that the design features better mobility and comfort in rough terrain with minimum turning radius, peak longitudinal acceleration, and root mean square reduced by 9.5%, 45.1%, and 21.4%, respectively.

The role of preSMA and STS in face recognition: A transcranial magnetic stimulation (TMS) study

Current models propose that facial recognition is mediated by two independent yet interacting anatomo-functional systems: one processing facial features mainly mediated by the Fusiform Face Area and the other involved in the extraction of dynamic information from faces, subserved by Superior Temporal Sulcus (STS). Also, the pre-Supplementary Motor Area (pre-SMA) is implicated in facial expression processing as it is involved in its motor mimicry. However, the literature only shows evidence of the implication of STS and preSMA for facial expression recognition, without relating it to face recognition. In addition, the literature shows a facilitatory role of facial motion in the recognition of unfamiliar faces, particularly for poor recognizers. The present study aimed at studying the role of STS and preSMA in unfamiliar face recognition in people with different face recognition skills. 34 healthy participants received repetitive transcranial magnetic stimulation over the right posterior STS, pre-SMA and as sham during a task of matching of faces encoded through: facial expression, rigid head movement or as static (i.e., absence of any facial or head motion). All faces were represented without emotional content. Results indicate that STS has a direct role in recognizing identities through rigid head movement and an indirect role in facial expression processing. This dissociation represents a step forward with respect to current face processing models suggesting that different types of motion involve separate brain and cognitive processes. PreSMA interacts with face recognition skills, increasing the performance of poor recognizers and decreasing that of good recognizers in all presentation conditions. Together, the results suggest the use of at least partially different mechanisms for face recognition in poor and good recognizers and a different role of STS and preSMA in face recognition.

Analysis for the Implementation of Distributed Renewable Energy Generation Systems for Areas of High Vulnerability Due to Hillside Movements: Case Study of Marianza-Cuenca, Ecuador

This research presents a renewable energy system that takes advantage of the energy potential available in the territory. This study emerges as a relevant option to provide solutions to geological risk areas where there are buildings that, due to emergency situations at certain times of the year during deep winter, are a target of danger and where its inhabitants would find it difficult to abandon their properties. The record of mass movements covering the city of Cuenca-Ecuador and part of the province has shown that the main triggering factor of this type of movement comprises the geological characteristics of tertiary formations characterized by lithological components that become unstable in the presence of water and due to their slopes being pronounced. Hybrid systems are effective solutions in distributed electricity generation, especially when it comes to helping people and their buildings in times of great need and the required electricity generation is basic. A hybrid photovoltaic, wind and hydrokinetic system has been designed that supplies electrical energy to a specific area on the opposite geographical side that is completely safe. The renewable energy system is connected to the public electricity grid available on site; however, in the event of an emergency the grid is disconnected for safety and only the hybrid system will work with the support of a battery backup system. In this study, the Homer Pro simulation tool was used and its results indicate that renewable systems that include PV, HKT and WT elements are economically viable, with a COE of USD 0.89/kWh.

Metachronal Motion of Biological and Artificial Cilia.

Cilia are slender, hair-like cell protrusions that are present ubiquitously in the natural world. They perform essential functions, such as generating fluid flow, propulsion, and feeding, in organisms ranging from protozoa to the human body. The coordinated beating of cilia, which results in wavelike motions known as metachrony, has fascinated researchers for decades for its role in functions such as flow generation and mucus transport. Inspired by nature, researchers have explored diverse materials for the fabrication of artificial cilia and developed several methods to mimic the metachronal motion observed in their biological counterparts. In this review, we will introduce the different types of metachronal motion generated by both biological and artificial cilia, the latter including pneumatically, photonically, electrically, and magnetically driven artificial cilia. Furthermore, we review the possible applications of metachronal motion by artificial cilia, focusing on flow generation, transport of mucus, particles, and droplets, and microrobotic locomotion. The overall aim of this review is to offer a comprehensive overview of the metachronal motions exhibited by diverse artificial cilia and the corresponding practical implementations. Additionally, we identify the potential future directions within this field. These insights present an exciting opportunity for further advancements in this domain.