Motor Performance Research Articles

Health monitoring and fault analysis of induction motors: a review

Abstract Induction motors are in high demand for industrial applications due to their reliable and efficient performance compared to other electrical motors. Therefore, the implementation of a predictive maintenance scheme is necessary to minimise financial losses in terms of revenue and maintenance costs. This scheme involves health monitoring system, aimed to enhance motor reliability, extend their useful lifespan and reduce maintenance expenses. Furthermore, traditional health monitoring systems often involve human intervention, which can slow down the diagnosis process. Therefore, a self-sufficient automated system has evolved to improve motor performance and reliability. This paper presents a comprehensive study of induction motor failures and the various methods used for their diagnosis. Additionally, it also discussed the importance of predictive maintenance and the pivotal role played by automated systems in ensuring the sustained efficiency of induction motors in industrial settings.

The effect of questioning gender stereotype threat on girl's standing long jump performance.

Over the past few years, the sport psychology literature has established that gender stereotype threat (ST) is one of the factors that can impair girls' performance. However, few studies have attempted to annihilate these negative effects. The purpose of the current study was to investigate whether questioning gender ST can mitigate the classical decline in girls' standing long jump (SLJ) performance. The participants were 120 girls (Mage = 10.74 ± 0.85 years), selected through convenience sampling and randomly assigned to three groups: the gender ST group (n = 40), the questioning group (n = 40), and the control group (n = 40). For all groups, baseline performance (i.e., SLJ) was measured by a female researcher following a warm-up period. In the experimental phase, the control group repeated the baseline conditions; the gender ST group completed the same test but was evaluated by a male examiner (i.e., implicit stereotype induction), while participants in the questioning group were assessed after receiving questioning statements while performing the task in front of a male examiner. The results of the present study showed that the induction of a gender ST leads to a decrease in SLJ in girls. Additionally, if these inducing conditions of gender ST are accompanied by a questioning condition, the negative effects of gender ST can be reduced, and SLJ in girls does not decline. Based on our findings, this intervention is recommended as a simple, inexpensive, and quick solution for mitigating the negative effects of gender ST on girl's motor performance.

Reliability, Concurrent Validity, Responsiveness and Measurement Error of the Portuguese Version of Comprehensive Motor Coordination Scale in Individuals With Parkinson's Disease.

Assessment of motor coordination in patients with Parkinson's disease (PD) is based on motor performance and does not consider movement quality. To validate the Comprehensive Coordination Scale (CCS) in patients with PD and correlate it with motor impairment. This cross-sectional and case-control study included 15 individuals with PD and 15 healthy older individuals as controls. Motor impairments were measured using the MDS-UPDRS (Part III). Motor coordination (CCS) was evaluated by five examiners and classified into four domains: upper and lower limbs and unilateral and bilateral tasks. CCS scores were compared between the groups using the Mann-Whitney test; concurrent validity was evaluated using Spearman's correlation between CCS and PD scales; and the inter-rate reliability was calculated by intraclass correlation coefficient (ICC). There was significant difference between the groups in the upper limb (p<0.001), lower limb (p=0.006), unilateral (p<0.001), bilateral (p=0.015), and total (p<0.001) CCS scores. Total CCS score (ICC 0.78), upper limb (ICC 0.71), lower limb (ICC 0.86) and unilateral (ICC 0.74) showed high inter-rate reliability. Bilateral domain (ICC 0.92) showed very high inter-rate reliability. And, there was negative correlation between CCS upper limb and postural tremor of hands (r=-0.716; p=0.008), unilateral CCS domain with postural tremor of hands (r=-0.687; p=0.012), and CCS total score with postural tremor of hands (r=-0.804; p=0.002). There was high inter-rater agreement for all CCS items, mainly in the lower limb and bilateral tasks. And, there was a moderate-to-very strong correlation between the total and sub-items of the CCS and motor impairment.

An in vivo and in silico probing of the protective potential of betaine against sodium fluoride-induced neurotoxicity.

Excessive fluoride exposure beyond the tolerable limit may adversely impacts brain functionality. Betaine (BET), a trimethyl glycine, possesses antioxidant, anti-inflammatory and anti-apoptotic functions, although the underlying mechanisms of the role of BET on fluoride-induced neurotoxicity remain unelucidated. To assess the mechanism involved in the neuro-restorative role of BET on behavioural, neurochemical, and histological changes, we employed a rat model of sodium fluoride (NaF) exposure. Animals were treated with NaF (9mg/kg) body weight (bw) only or co-treated with BET (50 and 100mg/kg bw) orally uninterrupted for 28 days. We obtained behavioural phenotypes in an open field, performed negative geotaxis, and a forelimb grip test, followed by oxido-inflammatory, apoptotic, and histological assessment. Behavioural endpoints indicated lessened locomotive and motor and heightened anxiety-like performance and upregulated oxidative, inflammatory, and apoptotic biomarkers in NaF-exposed rats. Co-treatment with BET significantly enhanced locomotive, motor, and anxiolytic performance, increased the antioxidant signalling mechanisms and demurred oxidative, inflammatory, and apoptotic biomarkers and histoarchitectural damage in the cerebrum and cerebellum cortices mediated by NaF. The in-silico analysis suggests that multiple hydrogen bonds and hydrophobic interactions of BET with critical amino acid residues, including arginine (ARG380 and ARG415) in the Keap1 Kelch domain, which may disrupt Keap1-Nrf2 complex and activate Nrf2. This may account for the observed increased in the Nrf2 levels, elevated antioxidant response and enhanced anti-inflammatory response. The BET-Keap1 complex was also observed to exhibit structural stability and conformational flexibility in solvated biomolecular systems, as indicated by the thermodynamic parameters computed from the trajectories obtained from a 100 ns full atomistic molecular dynamics simulation. Therefore, BET mediates neuroprotection against NaF-induced cerebro-cerebellar damage through rats' antioxidant, anti-inflammatory, and anti-apoptotic activity, which molecular interactions with Keap1-Nrf2 may drive.

Stiffness of elastic cuffs affects physiological and perceptual responses but not motor performance fatigue during low external load resistance exercise with practical blood flow restriction

ABSTRACT Practical blood flow restriction (pBFR), using non-pneumatic elastic cuffs, is a feasible and cost-effective alternative to pneumatic systems. There is evidence that cuff stiffness influences haemodynamic and perceptual responses in the upper body during rest. However, the impact of cuff stiffness during exercise is still unknown. Therefore, this study investigated the influence of cuff stiffness on physiological, perceptual, and performance changes during exercise. In a randomized and counterbalanced order, ten recreationally active males performed four sets of unilateral elbow flexions at 20% of individuals’ one-repetition-maximum with two elastic cuffs of different stiffness (low stiffness cuff [LS] and high stiffness cuff [HS]) each applied with two different overlaps (10% and 20% overlap in relation to the limb circumference) as well as a control condition without pBFR. Before and after exercise, maximal voluntary isometric contraction torque was measured to assess motor performance fatigue. During exercise, muscle oxygen saturation of the biceps brachii as well as effort and exercise-induced muscle pain perception were recorded. Statistical analysis revealed that motor performance fatigue was not different between conditions (BF10 = 0.289). The decline in muscle oxygen saturation (BF10 = 8.508 and BF10 = 1039.543) as well as effort (BF10 = 2646.104 and BF10 = 2.773∙106) and exercise-induced muscle pain perception (BF10 = 14087.983 and BF10 = 7.306∙109) were higher when using the stiffer cuff at 10% and 20% overlap, respectively. Conclusively, physiological and perceptual responses but not motor performance fatigue were affected by cuff stiffness when equal relative overlaps were applied.

Mathematical Optimization of Electric Motor Designs

When designing and improving the performance of electric motors, mathematical optimization is very important. The main goals are usually to make the motors more efficient, lower their costs, and work within certain limits. The main topic of this study is how to improve electric motor designs using advanced optimization methods, such as multi-objective optimization. The study looks at how to use different types of computer algorithms together, like gradient-based methods, genetic algorithms, and particle swarm optimization, to solve difficult design problems. Some of these problems are reducing energy loss, making the best use of materials, and finding the right balance between different performance measures such as speed, power density, and temperature management. Building mathematical models of the motor's physical and functional features is the first step in this method. Then, optimization methods are applied to these models. Finite element analysis (FEA) is used to correctly model the motor's electric behavior. This makes sure that the optimization process considers physical limits and nonlinearities that happen in the real world. The study also looks into how different design factors, like the shape of the motor's core, the way the windings are set up, and the materials used, affect its total performance. The study also looks at the fact that motor design has more than one goal by using Pareto front analysis to find the best ways to balance different goals. This lets people come up with motor designs that are good for speed, efficiency, and cost-effectiveness. Case studies of the design of different kinds of electric motors, such as induction motors, permanent magnet synchronous motors (PMSMs), and brushless DC motors (BLDCs), show that the proposed optimization method works well. The results show that mathematical optimization has the ability to make the planning process a lot better. This could lead to motors that work better, cost less, and are better suited to certain uses. The study ends with a talk of how optimization methods could be used in the future to improve the design of electric motors, especially for new technologies like electric cars and green energy systems.

Early progressive mobility to improve neurodevelopment of infants with severe bronchopulmonary dysplasia at a level IV neonatal intensive care unit: a prospective cohort study.

To measure the feasibility of early progressive mobility (EPM) in intubated infants with severe bronchopulmonary dysplasia (BPD) and compare neurodevelopmental skill acquisition of these infants before and after implementation of a clinical EPM program. Single-center pre-post intervention prospective cohort study in a level IV Neonatal Intensive Care Unit (NICU) from 2019-2022. Bivariate tests compared EPM interventions and results of serial Test of Infant Motor Performance (TIMP) assessments in 32 intubated infants with severe BPD cared for during two epochs, before and after NICU-wide EPM implementation. Infants in epoch 2 experienced significantly more EPM interventions than infants in epoch 1. Infants in epoch 2 also had more advanced motor skills on the TIMP than infants in epoch 1. There were no unplanned extubations. We demonstrated successful implementation of EPM in this high-risk population with evidence of beneficial impacts on early motor development.

Acoustic analysis of a three-dimensional cylindrical shell model under electromagnetic vibration

This paper presents the acoustic analysis of a three-dimensional cylindrical shell model under electromagnetic vibration, a critical factor affecting the performance of electric motors in various applications such as automotive, aerospace, and industrial systems. The study provides a multidisciplinary approach that integrates electromagnetics, structural vibration, and acoustics, solved using the fast multipole boundary element method (FMBEM). The results summarize the validation of the analytical models and numerical simulations, offering insights into effective vibration reduction methods. The conclusions indicate that the 3-D numerical analysis using FMBEM aligns well with the analytical solution for the sound pressure in the exterior acoustic domain of the cylindrical shell model. The paper contributes valuable insights for the design of low-noise motors and the control of electromagnetic vibration and noise in electric motors.

Design and experimental evaluation of a non-contact ultrasonic motor using acoustic phase holography

Abstract Non-contact ultrasonic motors address certain limitations of conventional ultrasonic motors. However, they continue to have intricate designs and electronics. Acoustic holography has emerged as a technique for its flexibility and dynamicity in manipulating acoustic phase and amplitude patterns in the nearfield, offering a reduction in mentioned complexities. Therefore, this technique may find utility in the development of non-contact ultrasonic motors. This paper discusses a novel design for non-contact rotary ultrasonic motor using acoustic holography. Acoustic holographic technique modulates the acoustic phase to create a phase gradient, resulting in a rotary flow that drives the rotor in the interface of aqueous media and air. The motor’s performance is influenced by factors such as the acoustic pressure amplitude, the number of 0 to 2 π pitches, and the rotor’s geometry. An empirical study using the Response Surface Method (RSM) identified an optimal number of pitches for maximum rotational speed at a constant voltage. The motor torque was measured by calculating the drag forces applied to the rotor blades. It was found that the minimum output torque occurs when the stator phase pitches match the rotor blades. The ideal motor performance is achieved with eight rotor blades and six phase pitches. The motor’s top speed reached 40 rpm, and the output torque varied around 0.1 μN.m, depending on the phase pitches and rotor blades. In summary, the research highlights the potential of acoustic holography in designing a non-contact ultrasonic motor, with specific configurations yielding optimal speed and torque.

Social isolation during the covid-19 pandemic impaired vitamin d concentrations, motor performance and physical fitness in adolescents

This study aims to verify the effect of social isolation arising from the Coronavirus pandemic (COVID-19) severe acute respiratory syndrome (SARS-CoV-2) on vitamin D (25(OH)D) concentrations, motor performance, and cardiorespiratory fitness (CRF) in adolescents. This research method is Case-control study, which included 34 boys, aged 12-16 years. In the pre-pandemic period, 17 schoolchildren were evaluated in December 2019, classified according to body mass index Z-score (BMI-z) as: eutrophic (n=8) and overweight (n=9). The post-pandemic group was composed of 17 boys, evaluated in March 2022, matched with the same BMI-z characteristics. Stature, body mass, fat mass (FM), fat free mass (FFM), flexibility (FLEX), 25(OH)D, absolute CRF (CRFabs) and relative (CRFrel) were assessed. The Supine-to-Stand test (STSTIME) execution time was used to assess motor performance and motor competence by the motor patterns used in execution (STSMC). considering p&lt;0.05 significant. The results showed that, post-pandemic, there were impairment on 25(OH)D, FLEX, STSTIME e CRF (p&lt;0.05). Both eutrophic and overweight groups reduced 25(OH)D concentrations (p&lt;0.001) and increased STSTIME (p=0.02) but did not modify STSMC. Regarding CRF, eutrophic individuals showed lower CRFabs and CRFrel values (p≤ 0.005), however no changes in the overweight group. We conclude that social isolation impaired the 25(OH)D concentrations and motor performance of adolescents. However, it stands out that the eutrophic were the most impacted with social isolation, as they showed unfavorable effect also on CRF.

Importance of Return to Usual and School Activities After Social Isolation in Recovering Vitamin D Concentrations, Physical Fitness, and Motor Performance in Adolescents

This study aimed to observe adolescents’ changes and individual responses regarding the anthropometry, cardiometabolic profile, vitamin D concentrations, physical fitness, and motor competence upon immediate return and three months of school activities after lockdown. Methods: The study included 28 adolescents (14.8 ± 0.8 years) of both sexes. Anthropometric measures, body composition, cardiometabolic parameters, physical fitness, and motor competence were assessed. A paired t-test was used to compare the frequencies of respondents and the effect size of the results, considering significant p &lt; 0.05. Results: After three months of school activities, adolescents changed their body composition, reducing % fat mass (p = 0.008) and increasing fat-free mass (p = 0.008). In terms of physical fitness, there was increased abdominal resistance (p &lt; 0.001; ES = −0.42) and motor performance, with reduction in supine-to-stand test time (p &lt; 0.001; ES = 0.53). There were very beneficial effects in reducing resting heart rate (p ≤ 0.001; ES = 0.61) and increasing vitamin D concentrations (p &lt; 0.001; ES = −0.61). After three months of a school routine, the proportions of change in respondents were similar between girls and boys and eutrophic individuals and overweight individuals. Conclusions: Returning to school activities after lockdown was important for the recovery of vitamin D concentrations, physical fitness, and motor competence, whose responses were independent of the level of adiposity and sex of the adolescents.

Early movement restriction impairs the development of sensorimotor integration, motor skills and memory in rats: Towards a preclinical model of developmental coordination disorder?

Children with neurodevelopmental disorders, such as developmental coordination disorder (DCD), exhibit gross to fine sensorimotor impairments, reduced physical activity and interactions with the environment and people. This disorder co-exists with cognitive deficits, executive dysfunctions and learning impairments. Previously, we demonstrated in rats that limited amounts and atypical patterns of movements and somatosensory feedback during early movement restriction manifested in adulthood as degraded postural and locomotor abilities, and musculoskeletal histopathology, including muscle atrophy, hyperexcitability within sensorimotor circuitry and maladaptive cortical plasticity, leading to functional disorganization of the primary somatosensory and motor cortices in the absence of cortical histopathology. In this study, we asked how this developmental sensorimotor restriction (SMR) started to impact the integration of multisensory information and the emergence of sensorimotor reflexes in rats. We also questioned the enduring impact of SMR on motor activities, pain and memory. SMR led to deficits in the emergence of swimming and sensorimotor reflexes, the development of pain and altered locomotor patterns and posture with toe-walking, adult motor performance and night spontaneous activity. In addition, SMR induced exploratory hyperactivity, short-term impairments in object-recognition tasks and long-term deficits in object-location tasks. SMR rats displayed minor alterations in histological features of the hippocampus, entorhinal, perirhinal and postrhinal cortices yet no obvious changes in the prefrontal cortex. Taken all together, these results show similarities with the symptoms observed in children with DCD, although further exploration seems required to postulate whether developmental SMR corresponds to a rat model of DCD.

Post-symptomatic administration of hMSCs exerts therapeutic effects in SCA2 mice

BackgroundDefects in the ataxin-2 (ATXN-2) protein and CAG trinucleotide repeat expansion in its coding gene, Atxn-2, cause the neurodegenerative disorder spinocerebellar ataxia type 2 (SCA2). While clinical studies suggest potential benefits of human-derived mesenchymal stem cells (hMSCs) for treating various ataxias, the exact mechanisms underlying their therapeutic effects and interaction with host tissue to stimulate neurotrophin expression remain unclear specifically in the context of SCA2.MethodsHuman bone marrow-derived MSCs (hMSCs) were injected into the cisterna magna of 26-week-old wild-type and SCA2 mice. Mice were assessed for impaired motor coordination using the accelerating rotarod, open field test, and composite phenotype scoring. At 50 weeks, the cerebellum vermis was harvested for protein assessment and immunohistochemical analysis.ResultsSignificant loss of NeuN and calbindin was observed in 25-week-old SCA2 mice. However, after receiving multiple injections of hMSCs starting at 26 weeks of age, these mice exhibited a significant improvement in abnormal motor performance and a protective effect on Purkinje cells. This beneficial effect persisted until the mice reached 50 weeks of age, at which point they were sacrificed to study further mechanistic events triggered by the administration of hMSCs. Calbindin-positive cells in the Purkinje cell layer expressed bone-derived neurotrophic factor after hMSC administration, contributing to the protection of cerebellar neurons from cell death.ConclusionIn conclusion, repeated administration of hMSCs shows promise in alleviating SCA2 symptoms by preserving Purkinje cells, improving neurotrophic support, and reducing inflammation, ultimately leading to the preservation of locomotor function in SCA2 mice.

Forecasting extremes of football players’ performance in matches

This study evaluates the use of simple linear or piecewise linear predictive models to predict extreme performance metrics in soccer matches, based on historical training and to match data of soccer players from RKS Raków Częstochowa football club. The data were collected from January to June 2023. The collected training and matched data average is 9000 records per month. A standard workweek at the RKS Academy consisted of 5 training units and at least 1 match. The best individual models found predict selected game performance metrics with a relative error of 2.3%, suggesting an excellent model fit between prediction and the actual value. This is illustrated by input data metric called “Metabolic Time Zone 5 and 6 Per Distance”, and output data by “Decelarations Total Distance in Zone 5 and 6 Per Distance”—calculated for in 3 min sliding window and characterized by the highest value of the generated parameter based on High Metabolic Load Distance (HMLD). The result concerns models run on aggregated performance metrics developed in APEX-PRO system using expert knowledge in soccer training, while raw GPS location-based models performing worse but still acceptably. Although we believe that the accuracy of the models still has limited reliability, their clarity and up-to-date quality make them useful in the daily planning of training activities and the management of workloads that affect player performance in the upcoming match, as well as the tactical decisions of the coach. More accurate predictions are given by individual models compared to aggregated models (player position), but there are exceptions where group models also perform very well. Adding a second metric to the input did not show a significant difference in the analyzed examples (the results are very similar). Our findings indicate that the model based on metrics from the last match also effectively predict extreme motor performances occurring in the game. In the case of the analyzed player, it was at the input “Accelerations Total Time Per Distance in Zone 6” at the output “Distance in Zone 6”. Specific training or match parameters can be key in predicting exceptional soccer performance, but they can also vary depending on the analyzed player. This confirms the need for further analysis of this issue.

Bearing Electrical Erosion Signal Detection Technique Based on Current Signal Analysis for Electric Motors

Abstract In modern industries, enhancing the efficiency and performance of electric motors is a critical requirement. Pulse width modulation (PWM) inverters utilized to enhance the energy efficiency of electric motors generate complex shaft voltages and bearing currents, leading to bearing electrical erosion. This study proposes a new method for detecting high-frequency (HF) circulating current and electric discharge machining (EDM) current signals in bearings for electric motors. The proposed method utilizes common mode voltage (CMV) and bearing current data, analyzing the relationship between these signals. Subsequently, it applies filtering techniques and differentiation for signal preprocessing. The Interquartile Range (IQR) method is used to detect outliers, classify HF circulating current and EDM current signals, and perform time-series data clustering to determine the occurrence frequency and timing of EDM signals. Finally, the implementation outcomes of the proposed method are validated, and its classification efficacy is evaluated and benchmarked against established methodologies through a comprehensive performance analysis. The proposed technique is anticipated to be applicable to the maintenance and prediction of modern electric motors in future developments, contributing to enhanced durability and reliability.

The Application of PID Control in DC Motor Control Systems

Abstract. The application of Proportional-Integral-Derivative (PID) control in direct current (DC) motor control systems is essential for achieving high levels of precision and reliability in both industrial and robotic applications. As DC motors are widely utilized in environments requiring accurate speed and torque control, this study seeks to address common challenges such as overshoot, instability, and sluggish response times that can compromise performance. The research is centered on the development and implementation of a PID-based control strategy using MATLAB/Simulink as the primary tool for simulation and testing. The study involves detailed simulation models and experimental validation, using data collected from controlled lab environments to evaluate the effectiveness of various tuning methods. These methods include adjusting the proportional, integral, and derivative gains to optimize motor responsiveness and system stability. The results indicate that with appropriate tuning, PID controllers can significantly enhance DC motor performance, leading to reduced overshoot, faster response times, and greater overall system reliability. The research concludes that adaptive PID control strategies, which dynamically adjust parameters in response to changing operating conditions, provide a robust solution for improving DC motor control in complex, dynamic, and nonlinear environments. This study lays the groundwork for future innovations in automation and precision-driven industries, offering insights that could be applied across a wide range of applications.

Stereoscopic objects affect reaching performance in virtual reality environments: influence of age on motor control

Although the stereoscopic effect in 3D virtual reality (VR) space has been studied, its influence on motor performance, specifically how stereoscopic objects affect behavioral outcomes like reaching, remains unclear. Previous research has primarily focused on perceptual aspects rather than on how stereoscopic visual input impacts motor control at the behavioral level. Thus, we investigated the effects of stereoscopic objects in a VR environment on reaching performance, examining whether the stereoscopic effect of objects is a significant aspect enough to affect performance at the behavioral level. While doing so, we investigated young and older adults separately, as age is a critical factor influencing motor performance. Fourteen young and 23 older participants performed a reaching task in the VR space. The target objects were 2D and 3D, deviating from the initial position by 10 and 20 cm. The movement attributed to feedforward control was analyzed using end-point error and smoothness of movement. Our results revealed that older participants had significantly worse predictive control than young participants in the 3D long task, suggesting that the positions of 3D objects were more difficult to predict than those of 2D objects. Young participants showed a significant difference in smoothness between 2D and 3D objects, which was not observed in older participants. This may reflect the floor effect in older participants. Under the short-distance condition, neither group showed a significant difference, suggesting the ceiling effect by distance. We confirmed that the effect of stereoscopic objects was not drastic but it did hamper the reaching performance.

Characterizing practice-dependent motor learning after a stroke.

After stroke, patients must learn to use residual motor function correctly. Consistently, motor learning is crucial in stroke motor recovery. We assessed motor performance, practice-dependent on-line motor learning, and factors potentially affecting them in stroke patients. This is a cross-sectional observational study. Twenty-six patients with first brain stroke leading to upper limb motor deficit in the subacute or chronic timeframe were enrolled. They performed a Finger Tapping Task (FTT) with both the affected and unaffected limbs. We assessed how patients learn to perform motor tasks despite the motor deficit and the differences in performance between the unaffected and affected limbs. Furthermore, by randomizing the order, we evaluated the possible inter-limb transfer of motor learning (i.e. transfer of a motor skill learned in one limb to the opposite one). Moreover, sleep, attention, anxiety, and depression were assessed through specific tests and questionnaires. Improved FTT accuracy and completed sequences for the affected limb were observed, even if lower than for the unaffected one. Furthermore, when patients initially performed the FTT with the unaffected limb, they showed higher accuracy in subsequent task completion with the affected limb than subjects who started with the affected limb. Only anxiety and attentional abilities showed significant correlations with motor performance. This work provides relevant insights into motor learning in stroke. Practice-dependent on-line motor learning is preserved in stroke survivors, and an inter-limb transfer effect can be observed. Attentional abilities and anxiety can affect learning after stroke, even if the effect of other factors cannot be excluded.

Performance improvement of a three phase induction squired-cage motor by winding topology configuration

The aim of this paper is to determine the optimal stator winding topology configuration for a 75 kW three-phase squirrel cage motor that provides the highest efficiency, power factor, and optimal starting parameters. The induction motor is simulated using Cedrat FLUX2D finite element software, which enables accurate modeling of its performance. Initially, the motor operation is simulated using the originally manufactured winding topology. Then, several alternative winding topology configurations are tested through numerical simulations. The performance results for each configuration are compared with those obtained from the original winding topology to identify the best option. The simulation results show that the shortened pitch concentric winding, combining both single and double layers, is the winding topology that offers the highest performance for the motor under study, significantly enhancing the overall efficiency of the system. These findings highlight the potential of optimized winding configurations in improving motor performance and energy efficiency.

What the visual system can learn from the non-dominant hand: The effect of graphomotor engagement on visual discrimination.

Previous studies have demonstrated that engaging in graphomotor activity for creating graphemes can enhance their subsequent visual discrimination. This suggests a positive influence of the motor system on visual learning. However, existing studies have emphasized the dominant hand, which is superiorly dexterous in fine-motor movements. This near-exclusive focus prompts the inquiry of whether the observed perceptual facilitation is a general characteristic of the motor system, or specific to pathways controlling the skilled over-trained dominant hand. Furthermore, the mechanistic underpinning of visual facilitation from graphomotor training (i.e., the individual contribution of motor activity, temporal evolution of the visual trace, variability of visual output) remain unclear. To address these questions, we assessed visual discrimination capabilities of healthy right-handed participants (N = 60) before and after graphomotor or visual training. Contrary to our initial expectation, graphomotor engagement with the non-dominant hand did not yield additional benefits to visual learning beyond those attainable through visual training alone. Moreover, graphomotor training with the non-dominant hand resulted in visual discrimination improvements comparable to those of dominant hand training, despite the inherent differences between hands in motor performance and in the amount of improvement in shape tracing throughout training. We conclude that the motor components of graphomotor activity may not be critical for visual learning of shapes through tracing activity. Instead, our results are in agreement with the symbolic theoretical account, suggesting that basic shape features required for discrimination can be acquired through visual inspection alone, providing a perspective on the improvements observed in prior studies.