The effect of induction motor shaft diameter on motor performance

Directory of Open Access Journals (Sweden)

Asım Gökhan Yetgin

2017-10-01

Full Text Available Induction motors are used in many areas from the past to the present and in different fields with the development of technology has continued to be used. It is obvious that induction motors as an improvement to the efficiency in terms of energy saving would cause great benefit. In that context, induction motor manufacturers and designers are constantly trying out new methods to improve motor performance and efficiency. In this study, what would be the optimum diameter of the shaft in order to increase the efficiency of the induction motor were investigated. In the study, 5.5 kW, 7.5 kW and 11 kW motors analyzes were also performed. Obtained shaft diameter values were compared with the manufacturer values. In addition, critical points such as the magnetic flux values, weight values and performances of the motors were examined and optimal shaft diameter values for each motor have been determined.

performance characteristics of an armature voltage controlled dc motor

African Journals Online (AJOL)

Dr Obe

. INTRODUCTION. The good control properties of the d.c. motor have made possible its initial large scale application in industry [1]. In spite of the present superiority of the solid state squirrel cage induction motor drive, especially at supply ...

Characteristics Analysis and Comparison of High-Speed 4/2 and Hybrid 4/4 Poles Switched Reluctance Motor

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Grace Firsta Lukman

2018-01-01

Full Text Available This paper presents a characteristics analysis and performance comparison of high-speed two-phase 4/2 and hybrid single-phase 4/4 switched reluctance motors (SRMs. Although the motors are advantageous as high-speed drives, both conventional structures have high torque ripple as a result of the presence of the torque dead zone. In this paper, solutions to the torque dead zone problem for each motor are discussed. For the 4/2 SRM, a wide-rotor stepper-type is adopted, while for the 4/4 SRM, the structure is changed to a hybrid by adding permanent magnets (PMs. Both motors have a non-uniform air gap to modify their inductance profile, which leads to the elimination of the torque dead zone. A finite-element method was used to analyze the characteristics of each motor. Then, the manufactured motors were tested through experiments, and lastly, their performance was compared.

The relative age effect on anthropometric characteristics and motor performances in Turkish children aged between 8 and 12 years

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Haslofça Ercan

2016-01-01

Full Text Available This study was carried out to investigate the effect of relative age on anthropometric properties and motor performance in Turkish children (girls n=423, boys n=601. Anthropometric measurement sites and techniques have been set out by the ISAK (International Society for the Advancement of Kinanthropometry. A group of tests involved in Eurofit Test Battery and other standard tests were used. For each age, the data of those who were born within the first three months and the last three months of the year were compared. The MedCalc Statistics Program was used for the differentiation and variation percentages between two periods were studied (p≤ 0.001, p= 0.05. Consequently effect of relative age was observed on anthropometric characteristics and motor performances of Turkish girls and boys between 8 and 12 years old. Researchers, trainers, families, sports managers and organizers are advised to consider Effect of Relative Age.

Split-phase motor running as capacitor starts motor and as capacitor run motor

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Yahaya Asizehi ENESI

2016-07-01

Full Text Available In this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The magnitude of capacitor that will develop maximum torque in capacitor start motor and capacitor run motor are investigated and determined by simulation. Each of these capacitors is connected to the auxiliary winding of split-phase motor thereby transforming it into capacitor start or capacitor run motor. The starting current and starting torque of the split-phase motor (SPM, capacitor run motor (CRM and capacitor star motor (CSM are compared for their suitability in their operational performance and applications.

The effectiveness of robotic training depends on motor task characteristics.

Science.gov (United States)

Marchal-Crespo, Laura; Rappo, Nicole; Riener, Robert

2017-12-01

Previous research suggests that the effectiveness of robotic training depends on the motor task to be learned. However, it is still an open question which specific task's characteristics influence the efficacy of error-modulating training strategies. Motor tasks can be classified based on the time characteristics of the task, in particular the task's duration (discrete vs. continuous). Continuous tasks require movements without distinct beginning or end. Discrete tasks require fast movements that include well-defined postures at the beginning and the end. We developed two games, one that requires a continuous movement-a tracking task-and one that requires discrete movements-a fast reaching task. We conducted an experiment with thirty healthy subjects to evaluate the effectiveness of three error-modulating training strategies-no guidance, error amplification (i.e., repulsive forces proportional to errors) and haptic guidance-on self-reported motivation and learning of the continuous and discrete games. Training with error amplification resulted in better motor learning than haptic guidance, besides the fact that error amplification reduced subjects' interest/enjoyment and perceived competence during training. Only subjects trained with error amplification improved their performance after training the discrete game. In fact, subjects trained without guidance improved the performance in the continuous game significantly more than in the discrete game, probably because the continuous task required greater attentional levels. Error-amplifying training strategies have a great potential to provoke better motor learning in continuous and discrete tasks. However, their long-lasting negative effects on motivation might limit their applicability in intense neurorehabilitation programs.

Motor competence and characteristics within the preschool environment.

Science.gov (United States)

True, Larissa; Pfeiffer, Karin Allor; Dowda, Marsha; Williams, Harriet G; Brown, William H; O'Neill, Jennifer R; Pate, Russell R

2017-08-01

Environmental characteristics within preschools that influence children's motor competence are largely unknown. The purpose of the present study was to examine the contribution of various preschool environmental characteristics to children's locomotor, object control, and total gross motor scores. Cross-sectional, observational study of 3-5 year-old children (n=229) from 22 preschools in South Carolina. The Children's Activity and Movement in Preschool Study (CHAMPS) Motor Skills Protocol assessed MC. Preschool directors provided information regarding policies and practices. The research team measured playgrounds and classrooms, and the Early Childhood Environment Rating Scale-Revised assessed preschool quality. Time spent in open space and electronic media use were also assessed using direct observation. The aforementioned variables predicted children's object control, locomotor, and total gross motor scores. Classroom size/child ratio, teacher education, playground size, electronic media use, and trips to outside organizations emerged as significant predictors of locomotor score and total motor score. The object control model was non-significant. Preschools may be able to promote motor competence by allowing children more time in open spaces, structured activity experiences, and by expanding existing outdoor playground space whenever possible. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Pressure-flow characteristics of normal and disordered esophageal motor patterns.

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Singendonk, Maartje M J; Kritas, Stamatiki; Cock, Charles; Ferris, Lara F; McCall, Lisa; Rommel, Nathalie; van Wijk, Michiel P; Benninga, Marc A; Moore, David; Omari, Taher I

2015-03-01

To perform pressure-flow analysis (PFA) in a cohort of pediatric patients who were referred for diagnostic manometric investigation. PFA was performed using purpose designed Matlab-based software. The pressure-flow index (PFI), a composite measure of bolus pressurization relative to flow and the impedance ratio, a measure of the extent of bolus clearance failure were calculated. Tracings of 76 pediatric patients (32 males; 9.1 ± 0.7 years) and 25 healthy adult controls (7 males; 36.1 ± 2.2 years) were analyzed. Patients mostly had normal motility (50%) or a category 4 disorder and usually weak peristalsis (31.5%) according to the Chicago Classification. PFA of healthy controls defined reference ranges for PFI ≤142 and impedance ratio ≤0.49. Pediatric patients with pressure-flow (PF) characteristics within these limits had normal motility (62%), most patients with PF characteristics outside these limits also had an abnormal Chicago Classification (61%). Patients with high PFI and disordered motor patterns all had esophagogastric junction outflow obstruction. Disordered PF characteristics are associated with disordered esophageal motor patterns. By defining the degree of over-pressurization and/or extent of clearance failure, PFA may be a useful adjunct to esophageal pressure topography-based classification. Copyright © 2015 Elsevier Inc. All rights reserved.

LEVEL OF ANTHROPOMETRIC CHARACTERISTICS AND MOTOR ABILITIES OF SEDENTARY AND CHILDREN WHO ARE IN TRAINING IN VARIOUS SPORTS ORIENTATION

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Nela Tatar

2011-09-01

Full Text Available Whit the goal to describe anthropometric characteristic and motorical abilities in groups of non sports and children which have some sports training activities, to calculate quantitative and qualitative difference between these groups of children in anthropometric characteristic and motorical abilities, it is conduct survey with the sample of 150 entities, age from 11 to 13, different sports orientation (karate, judo, football and volleyball and non sports children (scholars. In analyze, it was used system of total 27 variables (12 morphological and 15 basic - motorical. Also, descriptive statistical procedures were done and in this paper we present only arithmetical means. For quantitative difference between combination per groups in anthropometric characteristic and motorical abilities it was used ANOVA. According to quantitative and qualitative differences in anthropometric characteristics and motorical abilities from survey, the best anthropometric characteristic were get in groups of volleyball players, and in motorical abilities the best performance shown group of children which train a karate.

Split-phase motor running as capacitor starts motor and as capacitor run motor

OpenAIRE

Yahaya Asizehi ENESI; Jacob TSADO; Mark NWOHU; Usman Abraham USMAN; Odu Ayo IMORU

2016-01-01

In this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The ma...

Performance of claw-poled PM-stepping motor

International Nuclear Information System (INIS)

Liu, C.P.; Jeng, G.R.; Chen, W.C.; Tsai, M.C.; Wu, K.T.; Yao, Y.D.

2007-01-01

Present work is to analyze the performance of a permanent-magnetic (PM) stepping motor with claw poles by using the magnetic-circuit simulation technique. In this paper, we calculate the torque characteristics of the motor, such as the detent and the holding torques, and the step-position error by changing the gap between the upper and the lower stators and the staggered angle between the two stators. Through comparison of numerical data with experiment measurements, we found that the detent torque could be effectively reduced by increasing the stator-to-stator gap and further by decreasing the step-position error. Furthermore, the holding torque could be unchanged as the stator assemblage changed; however, it would be degenerated under the condition of low magnetization

Motor skills and functional characteristics of students of different somatotypes

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M.M. Kolokoltsev

2018-02-01

Full Text Available He purpose of the article is to study correlation of motor and functional characteristics of students of different somatotypes. Material : it was examined first year students (n=577, 17-18 years old. All students were trained in discipline “Physical education”. It was carried out somatotyping. It was considered motor skills and functional characteristics of students. Results : it was determined the reliable differences in values of parameters of motor tests and functional characteristics of students’ organism. It is determined that by the end of the first year of study the positive dynamics is registered: in sthenics (in two of seven motor tests; in asthenics (in four tests. It wasn’t found the reliable positive changes in group of hypersthenics. Students of sthenic and asthenic somatotypes have higher functional reserves of cardiorespiratory system, than girls of hypersthenics somatotype. Conclusions: constitutional features of motor skills and functional parameters of students of different somatotypes allow to concretize provisions of methodology of planning the individual differentiated training in discipline Physical education.

Motor performance in children with Noonan syndrome

NARCIS (Netherlands)

Croonen, E.A.; Essink, M.; Burgt, I. van der; Draaisma, J.M.; Noordam, C.; Nijhuis-Van der Sanden, M.W.G.

2017-01-01

Although problems with motor performance in daily life are frequently mentioned in Noonan syndrome, the motor performance profile has never been systematically investigated. The aim of this study was to examine whether a specific profile in motor performance in children with Noonan syndrome was seen

Effects of the friction coefficient on the torque characteristics of a hydraulic cam-rotor vane motor

Energy Technology Data Exchange (ETDEWEB)

Ma, Qiankun; Wang, Xuyong; Yuan, Fan; Chen, Liang Shen; Tao, Jian Feng [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai (China); Miao, Zhong Hua [School of Mechatronic Engineering and Automation, Shanghai University, Shanghai (China)

2016-08-15

The friction coefficient between the vane and the slot is one of the most critical factors that affects the performance of a continuous rotary hydraulic cam-rotor vane motor. To study the effects of this coefficient on the torque characteristics of the motor, the mathematical model for the normal force and the disturbing torque between the cam rotors and the vanes of the motor was established by analyzing the forces exerted on the vanes. The mathematical model was simulated with MATLAB, and simulation results show that an increase in the friction coefficient would simultaneously decrease the normal force and increase the disturbing torque, which would negatively affect the performance of the motor. Further experimental research indicated that the low-speed performance of the hydraulic cam-rotor motor was significantly improved when the friction coefficient was reduced by controlling the parallelism tolerance, flatness and roughness between the vanes and the slots.

Anthropometric and motor performance characteristics of futsal athletes in different categories

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Edilson Serpeloni Cyrino

2007-09-01

Full Text Available The objective of this study was to analyze the anthropometric characteristics of young futsal (fi ve-a-side soccer players and to make comparisons between different competitive categories. To this end, 232 male athletes aged 8 to 18 years, playing in the following categories: under-9 (8-9 years; n = 56, under-11 (10-11 years; n = 62, under-13 (12-13 years; n = 36, under-15 (14-15 years; n = 29, under-17 (16-17 years; n = 35 and under-19 (18 years; n = 14, underwent anthropometric measurement to obtain body mass (MB, height, middle-upper arm circumference and skin fold thicknesses (triceps and subscapular. Based on these measurements, body mass index (BMI, sum of skin folds thickness (ΣSF, relative body fat (%fat and muscular area of the arm (MAB were all calculated. Motor performance was analyzed based on the results of the following tests: modifi ed 1-minute abdominal (ABD, horizontal impulse (HI, 9/12 minute walk/run (9/12 min and medicine ball throw (MB. Categories were compared using one-way ANOVA, followed by Scheffé’s post hoc test when p ABSTRACT O propósito do presente estudo foi analisar as características antropométricas de jovens atletas de futsal e, posteriormente, estabelecer comparações entre diferentes categorias competitivas. Para tanto, 232 atletas do sexo masculino, de 8 a 18 anos, das categorias sub 9 (8-9 anos; n = 56, sub 11 (10-11 anos; n = 62, sub 13 (12-13 anos; n = 36, sub 15 (14-15 anos; n = 29, sub 17 (16-17 anos; n = 35 e sub 19 (18 anos; n = 14 foram submetidos a medidas antropométricas de massa corporal (MC, estatura, perímetro braquial e espessura de dobras cutâneas (tríceps e subescapular. A partir dessas medidas foram determinados o índice de massa corporal (IMC, o somatório de espessura de dobras cutâneas (ΣDC, a gordura corporal relativa (% gordura e a área muscular do braço (AMB. O desempenho motor foi analisado a partir dos seguintes testes motores: abdominal modifi cado 1 minuto (ABD

Relationship between Grooming Performance and Motor and Cognitive Functions in Stroke Patients with Receiver Operating Characteristic Analysis.

Science.gov (United States)

Fujita, Takaaki; Sato, Atsushi; Tsuchiya, Kenji; Ohashi, Takuro; Yamane, Kazuhiro; Yamamoto, Yuichi; Iokawa, Kazuaki; Ohira, Yoko; Otsuki, Koji; Tozato, Fusae

2017-12-01

This study aimed to elucidate the relationship between grooming performance of stroke patients and various motor and cognitive functions and to examine the cognitive and physical functional standards required for grooming independence. We retrospectively analyzed the data of 96 hospitalized patients with first stroke in a rehabilitation hospital ward. Logistic regression analysis and receiver operating characteristic curves were used to investigate the related cognitive and motor functions with grooming performance and to calculate the cutoff values for independence and supervision levels in grooming. For analysis between the independent and supervision-dependent groups, the only item with an area under the curve (AUC) of .9 or higher was the Berg Balance Scale, and the calculated cutoff value was 41/40 (sensitivity, 83.6%; specificity, 87.8%). For analysis between the independent-supervision and dependent groups, the items with an AUC of .9 or higher were the Simple Test for Evaluating Hand Function (STEF) on the nonaffected side, Vitality Index (VI), and FIM ® cognition. The cutoff values were 68/67 for the STEF (sensitivity, 100%; specificity, 72.2%), 9/8 points for the VI (sensitivity, 92.3%; specificity, 88.9%), and 23/22 points for FIM ® cognition (sensitivity, 91.0%; specificity, 88.9%). Our results suggest that upper-extremity functions on the nonaffected side, motivation, and cognitive functions are particularly important to achieve the supervision level and that balance is important to reach the independence level. The effective improvement of grooming performance is possible by performing therapeutic or compensatory intervention on functions that have not achieved these cutoff values. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Measurement of Static Characteristics Pneumatic Motors with Elastic Working Elements

Directory of Open Access Journals (Sweden)

Kamil FOJTÁŠEK

2012-06-01

Full Text Available Into a category of pneumatic motors with elastic working parts belong air bellows, diaphragm motors and fluid muscles. All three types of these motors have some elastic part usually made of rubber. This part is deformed under the pressure of a compressed air or a mass load resulting in a final working effect. This paper deals with measuring of static characteristics of these motors.

Comparison of Linear Induction Motor Theories for the LIMRV and TLRV Motors

Science.gov (United States)

1978-01-01

The Oberretl, Yamamura, and Mosebach theories of the linear induction motor are described and also applied to predict performance characteristics of the TLRV & LIMRV linear induction motors. The effect of finite motor width and length on performance ...

Association between Body Composition and Motor Performance in Preschool Children

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Tanja H. Kakebeeke

2017-09-01

Full Text Available Objective: Being overweight makes physical movement more difficult. Our aim was to investigate the association between body composition and motor performance in preschool children. Methods: A total of 476 predominantly normal-weight preschool children (age 3.9 ± 0.7 years; m/f: 251/225; BMI 16.0 ± 1.4 kg/m2 participated in the Swiss Preschoolers' Health Study (SPLASHY. Body composition assessments included skinfold thickness, waist circumference (WC, and BMI. The Zurich Neuromotor Assessment (ZNA was used to assess gross and fine motor tasks. Results: After adjustment for age, sex, socioeconomic status, sociocultural characteristics, and physical activity (assessed with accelerometers, skinfold thickness and WC were both inversely correlated with jumping sideward (gross motor task β-coefficient -1.92, p = 0.027; and -3.34, p = 0.014, respectively, while BMI was positively correlated with running performance (gross motor task β-coefficient 9.12, p = 0.001. No significant associations were found between body composition measures and fine motor tasks. Conclusion: The inverse associations between skinfold thickness or WC and jumping sideward indicates that children with high fat mass may be less proficient in certain gross motor tasks. The positive association between BMI and running suggests that BMI might be an indicator of fat-free (i.e., muscle mass in predominately normal-weight preschool children.

Dynamic characteristic of electromechanical coupling effects in motor-gear system

Science.gov (United States)

Bai, Wenyu; Qin, Datong; Wang, Yawen; Lim, Teik C.

2018-06-01

Dynamic characteristics of an electromechanical model which combines a nonlinear permeance network model (PNM) of a squirrel-cage induction motor and a coupled lateral-torsional dynamic model of a planetary geared rotor system is analyzed in this study. The simulations reveal the effects of internal excitations or parameters like machine slotting, magnetic saturation, time-varying mesh stiffness and shaft stiffness on the system dynamics. The responses of the electromechanical system with PNM motor model are compared with those responses of the system with dynamic motor model. The electromechanical coupling due to the interactions between the motor and gear system are studied. Furthermore, the frequency analysis of the electromechanical system dynamic characteristics predicts an efficient way to detect work condition of unsymmetrical voltage sag.

Skeletal maturation, fundamental motor skills and motor performance in preschool children.

Science.gov (United States)

Freitas, D L; Lausen, B; Maia, J A; Gouveia, É R; Antunes, A M; Thomis, M; Lefevre, J; Malina, R M

2018-06-01

Relationships among skeletal age (SA), body size and fundamental motor skills (FMS) and motor performance were considered in 155 boys and 159 girls 3-6 years of age. Stature and body mass were measured. SA of the hand-wrist was assessed with the Tanner-Whitehouse II 20 bone method. The Test of Gross Motor Development, 2 nd edition (TGMD-2) and the Preschool Test Battery were used, respectively, to assess FMS and motor performance. Based on hierarchical regression analyses, the standardized residuals of SA on chronological age (SAsr) explained a maximum of 6.1% of the variance in FMS and motor performance in boys (ΔR 2 3 , range 0.0% to 6.1%) and a maximum of 20.4% of the variance in girls (ΔR 2 3 , range 0.0% to 20.4%) over that explained by body size and interactions of SAsr with body size (step 3). The interactions of the SAsr and stature and body mass (step 2) explained a maximum of 28.3% of the variance in boys (ΔR 2 2 , range 0.5% to 28.3%) and 16.7% of the variance in girls (ΔR 2 2 , range 0.7% to 16.7%) over that explained by body size alone. With the exception of balance, relationships among SAsr and FMS or motor performance differed between boys and girls. Overall, SA per se or interacting with body size had a relatively small influence in FMS and motor performance in children 3-6 years of age. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Motor unit recruitment by size does not provide functional advantages for motor performance.

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Dideriksen, Jakob L; Farina, Dario

2013-12-15

It is commonly assumed that the orderly recruitment of motor units by size provides a functional advantage for the performance of movements compared with a random recruitment order. On the other hand, the excitability of a motor neuron depends on its size and this is intrinsically linked to its innervation number. A range of innervation numbers among motor neurons corresponds to a range of sizes and thus to a range of excitabilities ordered by size. Therefore, if the excitation drive is similar among motor neurons, the recruitment by size is inevitably due to the intrinsic properties of motor neurons and may not have arisen to meet functional demands. In this view, we tested the assumption that orderly recruitment is necessarily beneficial by determining if this type of recruitment produces optimal motor output. Using evolutionary algorithms and without any a priori assumptions, the parameters of neuromuscular models were optimized with respect to several criteria for motor performance. Interestingly, the optimized model parameters matched well known neuromuscular properties, but none of the optimization criteria determined a consistent recruitment order by size unless this was imposed by an association between motor neuron size and excitability. Further, when the association between size and excitability was imposed, the resultant model of recruitment did not improve the motor performance with respect to the absence of orderly recruitment. A consistent observation was that optimal solutions for a variety of criteria of motor performance always required a broad range of innervation numbers in the population of motor neurons, skewed towards the small values. These results indicate that orderly recruitment of motor units in itself does not provide substantial functional advantages for motor control. Rather, the reason for its near-universal presence in human movements is that motor functions are optimized by a broad range of innervation numbers.

Improvement of the environmental and operational characteristics of vehicles through decreasing the motor fuel density.

Science.gov (United States)

Magaril, Elena

2016-04-01

The environmental and operational characteristics of motor transport, one of the main consumers of motor fuel and source of toxic emissions, soot, and greenhouse gases, are determined to a large extent by the fuel quality which is characterized by many parameters. Fuel density is one of these parameters and it can serve as an indicator of fuel quality. It has been theoretically substantiated that an increased density of motor fuel has a negative impact both on the environmental and operational characteristics of motor transport. The use of fuels with a high density leads to an increase in carbonization within the engine, adversely affecting the vehicle performance and increasing environmental pollution. A program of technological measures targeted at reducing the density of the fuel used was offered. It includes a solution to the problem posed by changes in the refining capacities ratio and the temperature range of gasoline and diesel fuel boiling, by introducing fuel additives and adding butanes to the gasoline. An environmental tax has been developed which allows oil refineries to have a direct impact on the production of fuels with improved environmental performance, taking into account the need to minimize the density of the fuel within a given category of quality.

Structural Correlates of Skilled Performance on a Motor Sequence Task

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Christopher J Steele

2012-10-01

Full Text Available The brain regions functionally engaged in motor sequence performance are well established, but the structural characteristics of these regions and the fibre pathways involved have been less well studied. In addition, relatively few studies have combined multiple magnetic resonance imaging (MRI and behavioural performance measures in the same sample. Therefore, the current study used diffusion tensor imaging, probabilistic tractography, and voxel-based morphometry to determine the structural correlates of skilled motor performance. Further, we compared these findings with fMRI results in the same sample. We correlated final performance and rate of improvement measures on a temporal motor sequence task with skeletonised fractional anisotropy (FA and whole brain grey matter (GM volume. Final synchronisation performance was negatively correlated with FA in white matter underlying bilateral sensorimotor cortex – an effect that was mediated by a positive correlation with radial diffusivity. Multi-fibre tractography indicated that this region contained crossing fibres from the corticospinal tract and superior longitudinal fasciculus (SLF. The identified SLF pathway linked parietal and auditory cortical regions that have been shown to be functionally engaged in this task. Thus, we hypothesise that enhanced synchronisation performance on this task may be related to greater fibre integrity of the SLF. Rate of improvement on synchronisation was positively correlated with GM volume in cerebellar lobules HVI and V – regions that showed training-related decreases in activity in the same sample. Taken together, our results link individual differences in brain structure and function to motor sequence performance on the same task. Further, our study illustrates the utility of using multiple MR measures and analysis techniques to specify the interpretation of structural findings.

Influence of operating conditions upon the dynamic steady-state performance of a switched reluctance motor

International Nuclear Information System (INIS)

Faiz, J.; Shafagh, E.

1999-01-01

In order to obtain more accurate predicted dynamic steady-state performance with shorter computation time, an available mathematical model is modified and presented. Using this modified model, performance of a typical switched reluctance motor under a wide range of variations of operating conditions is obtained and discussed. These include variations of speed, voltage, load and switching angle. The static test characteristics of the motor are carefully measured and measured flux-linkage data are then used to predict the steady-state performance

Talent in Female Gymnastics: a Survival Analysis Based upon Performance Characteristics.

Science.gov (United States)

Pion, J; Lenoir, M; Vandorpe, B; Segers, V

2015-11-01

This study investigated the link between the anthropometric, physical and motor characteristics assessed during talent identification and dropout in young female gymnasts. 3 cohorts of female gymnasts (n=243; 6-9 years) completed a test battery for talent identification. Performance-levels were monitored over 5 years of competition. Kaplan-Meier and Cox Proportional Hazards analyses were conducted to determine the survival rate and the characteristics that influence dropout respectively. Kaplan-Meier analysis indicated that only 18% of the female gymnasts that passed the baseline talent identification test survived at the highest competition level 5 years later. The Cox Proportional Hazards Model indicated that gymnasts with a score in the best quartile for a specific characteristic significantly increased chances of survival by 45-129%. These characteristics being: basic motor skills (129%), shoulder strength (96%), leg strength (53%) and 3 gross motor coordination items (45-73%). These results suggest that tests batteries commonly used for talent identification in young female gymnasts may also provide valuable insights into future dropout. Therefore, multidimensional test batteries deserve a prominent place in the selection process. The individual test results should encourage trainers to invest in an early development of basic physical and motor characteristics to prevent attrition. © Georg Thieme Verlag KG Stuttgart · New York.

Motor and cognitive performance of overweight preschool children.

Science.gov (United States)

Krombholz, Heinz

2013-02-01

Gross and fine motor skills and cognitive performance in obese and overweight children were compared to healthy weight children. Participants were 1,543 children (797 boys and 746 girls) ages 43 to 84 months, attending childcare centers in Munich, Germany. According to German Body Mass Index (BMI) standards for age and sex, 4.6% of the children were classified as obese (percentile greater or equal 97), 6.8% as overweight (percentile greater or equal 90 and less than 97), 5.9% as underweight (percentile less than 10), and 83.1% as being of healthy weight. Dependent variables were physical characteristics (height, weight, skinfold thickness), physical fitness (standing broad jump, shuttle run, hanging), body coordination (balancing forward, balancing backward, lateral jump, hopping), manual dexterity (right and left hand), and cognitive performance (intelligence, verbal ability, concentration). Higher proportions of children from lower socioeconomic and immigrant backgrounds were overweight. There was no association between weight and sex. Overweight children showed lower performance on gross motor skills (coordination and fitness), manual dexterity, and intelligence compared to healthy weight children, even after controlling for the effects of social class and immigration status.

Dynamic characteristics of motor-gear system under load saltations and voltage transients

Science.gov (United States)

Bai, Wenyu; Qin, Datong; Wang, Yawen; Lim, Teik C.

2018-02-01

In this paper, a dynamic model of a motor-gear system is proposed. The model combines a nonlinear permeance network model (PNM) of a squirrel-cage induction motor and a coupled lateral-torsional dynamic model of a planetary geared rotor system. The external excitations including voltage transients and load saltations, as well as the internal excitations such as spatial effects, magnetic circuits topology and material nonlinearity in the motor, and time-varying mesh stiffness and damping in the planetary gear system are considered in the proposed model. Then, the simulation results are compared with those predicted by the electromechanical model containing a dynamic motor model with constant inductances. The comparison showed that the electromechanical system model with the PNM motor model yields more reasonable results than the electromechanical system model with the lumped-parameter electric machine. It is observed that electromechanical coupling effect can induce additional and severe gear vibrations. In addition, the external conditions, especially the voltage transients, will dramatically affect the dynamic characteristics of the electromechanical system. Finally, some suggestions are offered based on this analysis for improving the performance and reliability of the electromechanical system.

Relationship between Motor Symptoms, Cognition, and Demographic Characteristics in Treated Mild/Moderate Parkinson's Disease.

Directory of Open Access Journals (Sweden)

Jay S Schneider

Full Text Available Although Parkinson's disease (PD is a progressive neurodegenerative disorder characterized primarily by motor symptoms, PD patients, at all stages of the disease, can experience cognitive dysfunction. However, the relationships between cognitive and motor symptoms and specific demographic characteristics are not well defined, particularly for patients who have progressed to requiring dopaminergic medication.To examine relationships between motor and cognitive symptoms and various demographic factors in mild to moderate, PD patients requiring anti-PD medication.Cognitive function was assessed in 94 subjects with a variety of neuropsychological tests during baseline evaluations as part of an experimental treatment study. Data were analyzed in relation to Unified Parkinson's Disease Rating Scale motor scores and demographic variables.Of the UPDRS subscores analyzed, posture/balance/gait was associated with the highest number of adverse cognitive outcomes followed by speech/facial expression, bradykinesia, and rigidity. No associations were detected between any of the cognitive performance measures and tremor. Motor functioning assessed in the "off" condition correlated primarily with disease duration; neuropsychological performance in general was primarily related to age.In PD patients who have advanced to requiring anti-PD therapies, there are salient associations between axial signs and cognitive performance and in particular, with different aspects of visuospatial function suggesting involvement of similar circuits in these functions. Associations between executive functions and bradykinesia also suggest involvement similar circuits in these functions.

Motor performance in children with Noonan syndrome.

Science.gov (United States)

Croonen, Ellen A; Essink, Marlou; van der Burgt, Ineke; Draaisma, Jos M; Noordam, Cees; Nijhuis-van der Sanden, Maria W G

2017-09-01

Although problems with motor performance in daily life are frequently mentioned in Noonan syndrome, the motor performance profile has never been systematically investigated. The aim of this study was to examine whether a specific profile in motor performance in children with Noonan syndrome was seen using valid norm-referenced tests. The study assessed motor performance in 19 children with Noonan syndrome (12 females, mean age 9 years 4 months, range 6 years 1 month to 11 years and 11 months, SDS 1 year and 11 months). More than 60% of the parents of the children reported pain, decreased muscle strength, reduced endurance, and/or clumsiness in daily functioning. The mean standard scores on the Visual Motor Integration (VMI) test and Movement Assessment Battery for Children 2, Dutch version (MABC-2-NL) items differed significantly from the reference scores. Grip strength, muscle force, and 6 min Walking Test (6 MWT) walking distance were significantly lower, and the presence of generalized hypermobility was significantly higher. All MABC-2-NL scores (except manual dexterity) correlated significantly with almost all muscle strength tests, VMI total score, and VMI visual perception score. The 6 MWT was only significantly correlated to grip strength. This is the first study that confirms that motor performance, strength, and endurance are significantly impaired in children with Noonan syndrome. Decreased functional motor performance seems to be related to decreased visual perception and reduced muscle strength. Research on causal relationships and the effectiveness of interventions is needed. Physical and/or occupational therapy guidance should be considered to enhance participation in daily life. © 2017 Wiley Periodicals, Inc.

Design and performance testing of an ultrasonic linear motor with dual piezoelectric actuators.

Science.gov (United States)

Smithmaitrie, Pruittikorn; Suybangdum, Panumas; Laoratanakul, Pitak; Muensit, Nantakan

2012-05-01

In this work, design and performance testing of an ultrasonic linear motor with dual piezoelectric actuator patches are studied. The motor system consists of a linear stator, a pre-load weight, and two piezoelectric actuator patches. The piezoelectric actuators are bonded with the linear elastic stator at specific locations. The stator generates propagating waves when the piezoelectric actuators are subjected to harmonic excitations. Vibration characteristics of the linear stator are analyzed and compared with finite element and experimental results. The analytical, finite element, and experimental results show agreement. In the experiments, performance of the ultrasonic linear motor is tested. Relationships between velocity and pre-load weight, velocity and applied voltage, driving force and applied voltage, and velocity and driving force are reported. The design of the dual piezoelectric actuators yields a simpler structure with a smaller number of actuators and lower stator stiffness compared with a conventional design of an ultrasonic linear motor with fully laminated piezoelectric actuators.

Effect of rotor rectifier on motor performance in slip recovery drives

Energy Technology Data Exchange (ETDEWEB)

Al Zahawi, B.A.T.; Jones, B.L.; Drury, W.

1987-01-01

The static Kramer system, comprising a slip-ring induction motor and a slip energy recovery circuit, is one of the simplest and most efficient forms of ac variable-speed drive. It is sometimes used to upgrade drives which had originally been designed for fixed speed operation, often with substantial energy savings. In such cases, it is important to know how the inclusion of a rectifier in the slip energy recovery circuit affects motor performance. A satisfactory model for the motor-rectifier combination is also needed to provide a sound basis for assessing alternative forms of recovery systems which aim to overcome the principal shortcomings of the drive, namely the magnitude and variability of its reactive power. Despite its simplicity, the Kramer drive presents a formidable analytical challenge. Rigorous analysis is particularly difficult and there is a need for a simpler form of analysis when calculating ratings and steady-state performance. The approach taken in this paper uses a transformer-type model for the motor, and largely analytical expressions for predicting torque, stator power, stator reactive power and rectifier output voltage. Motor resistances, diode characteristics, and the several possible rectifier overlap modes are included. It is shown that the rectifier has an adverse effect on stator reactive power, power factor, and peak torque, particularly at speeds well below synchronous, requiring some derating of motors designed for resistance control and also requiring additional power factor correction. While the analysis does not cater to variations caused by harmonics at some speeds, it does provide a quick, accurate method of predicting performance over most sections of the operating range. 12 refs., 11 figs.

Motor network structure and function are associated with motor performance in Huntington's disease.

Science.gov (United States)

Müller, Hans-Peter; Gorges, Martin; Grön, Georg; Kassubek, Jan; Landwehrmeyer, G Bernhard; Süßmuth, Sigurd D; Wolf, Robert Christian; Orth, Michael

2016-03-01

In Huntington's disease, the relationship of brain structure, brain function and clinical measures remains incompletely understood. We asked how sensory-motor network brain structure and neural activity relate to each other and to motor performance. Thirty-four early stage HD and 32 age- and sex-matched healthy control participants underwent structural magnetic resonance imaging (MRI), diffusion tensor, and intrinsic functional connectivity MRI. Diffusivity patterns were assessed in the cortico-spinal tract and the thalamus-somatosensory cortex tract. For the motor network connectivity analyses the dominant M1 motor cortex region and for the basal ganglia-thalamic network the thalamus were used as seeds. Region to region structural and functional connectivity was examined between thalamus and somatosensory cortex. Fractional anisotropy (FA) was higher in HD than controls in the basal ganglia, and lower in the external and internal capsule, in the thalamus, and in subcortical white matter. Between-group axial and radial diffusivity differences were more prominent than differences in FA, and correlated with motor performance. Within the motor network, the insula was less connected in HD than in controls, with the degree of connection correlating with motor scores. The basal ganglia-thalamic network's connectivity differed in the insula and basal ganglia. Tract specific white matter diffusivity and functional connectivity were not correlated. In HD sensory-motor white matter organization and functional connectivity in a motor network were independently associated with motor performance. The lack of tract-specific association of structure and function suggests that functional adaptation to structural loss differs between participants.

Study on the Rollover Characteristic of In-Wheel-Motor-Driven Electric Vehicles Considering Road and Electromagnetic Excitation

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Di Tan

2016-01-01

Full Text Available For in-wheel-motor-driven electric vehicles, the motor is installed in the wheel directly. Tyre runout and uneven load can cause magnet gap deformation in the motor, which will produce electromagnetic forces that further influence the vehicle rollover characteristics. To study the rollover characteristics, a verified 16-degree-of-freedom rollover dynamic model is introduced. Next, the vehicle rollover characteristics both with and without electromagnetic force are analyzed under conditions of the Fixed Timing Fishhook steering and grade B road excitation. The results show that the electromagnetic force has a certain effect on the load transfer and can reduce the antirollover performance of the vehicle. Therefore, the effect of the electromagnetic force on the rollover characteristic should be considered in the vehicle design. To this end, extensive analysis was conducted on the effect of the road level, vehicle speed, and the road adhesion coefficient on the vehicle rollover stability. The results indicate that vehicle rollover stability worsens when the above-mentioned factors increase, the most influential factor being the road adhesion coefficient followed by vehicle speed and road level. This paper can offer certain theory basis for the design of the in-wheel-motor-driven electric vehicles.

Gross motor skill performance in children with and without visual impairments--research to practice.

Science.gov (United States)

Wagner, Matthias O; Haibach, Pamela S; Lieberman, Lauren J

2013-10-01

The aim of this study was to provide an empirical basis for teaching gross motor skills in children with visual impairments. For this purpose, gross motor skill performance of 23, 6-12 year old, boys and girls who are blind (ICD-10 H54.0) and 28 sighted controls with comparable age and gender characteristics was compared on six locomotor and six object control tasks using the Test of Gross Motor Development-Second Edition. Results indicate that children who are blind perform significantly (pskills, whereby running, leaping, kicking and catching are the most affected skills, and corresponding differences are related to most running, leaping, kicking and catching component. Practical implications are provided. Copyright © 2013 Elsevier Ltd. All rights reserved.

Auditory and motor imagery modulate learning in music performance.

Science.gov (United States)

Brown, Rachel M; Palmer, Caroline

2013-01-01

Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians' encoding (during Learning, as they practiced novel melodies), and retrieval (during Recall of those melodies). Pianists learned melodies by listening without performing (auditory learning) or performing without sound (motor learning); following Learning, pianists performed the melodies from memory with auditory feedback (Recall). During either Learning (Experiment 1) or Recall (Experiment 2), pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced) and temporal regularity (variability of quarter-note interonset intervals) were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists' pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2). Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1): Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2): Higher auditory imagery skill predicted greater temporal regularity during Recall in the presence of

Auditory and motor imagery modulate learning in music performance

Science.gov (United States)

Brown, Rachel M.; Palmer, Caroline

2013-01-01

Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians' encoding (during Learning, as they practiced novel melodies), and retrieval (during Recall of those melodies). Pianists learned melodies by listening without performing (auditory learning) or performing without sound (motor learning); following Learning, pianists performed the melodies from memory with auditory feedback (Recall). During either Learning (Experiment 1) or Recall (Experiment 2), pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced) and temporal regularity (variability of quarter-note interonset intervals) were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists' pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2). Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1): Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2): Higher auditory imagery skill predicted greater temporal regularity during Recall in the presence of

Starting characteristics of direct current motors powered by solar cells

Science.gov (United States)

Singer, S.; Appelbaum, J.

1989-01-01

Direct current motors are used in photovoltaic systems. Important characteristics of electric motors are the starting to rated current and torque ratios. These ratios are dictated by the size of the solar cell array and are different for the various dc motor types. Discussed here is the calculation of the starting to rated current ratio and starting to rated torque ratio of the permanent magnet, and series and shunt excited motors when powered by solar cells for two cases: with and without a maximum-power-point-tracker (MPPT) included in the system. Comparing these two cases, one gets a torque magnification of about 3 for the permanent magnet motor and about 7 for other motor types. The calculation of the torques may assist the PV system designer to determine whether or not to include an MPPT in the system.

Task-irrelevant auditory feedback facilitates motor performance in musicians

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Virginia eConde

2012-05-01

Full Text Available An efficient and fast auditory–motor network is a basic resource for trained musicians due to the importance of motor anticipation of sound production in musical performance. When playing an instrument, motor performance always goes along with the production of sounds and the integration between both modalities plays an essential role in the course of musical training. The aim of the present study was to investigate the role of task-irrelevant auditory feedback during motor performance in musicians using a serial reaction time task (SRTT. Our hypothesis was that musicians, due to their extensive auditory–motor practice routine during musical training, have a superior performance and learning capabilities when receiving auditory feedback during SRTT relative to musicians performing the SRTT without any auditory feedback. Here we provide novel evidence that task-irrelevant auditory feedback is capable to reinforce SRTT performance but not learning, a finding that might provide further insight into auditory-motor integration in musicians on a behavioral level.

Performance analysis of PM synchronous motor using fuzzy logic and self tuning fuzzy PI speed controls

International Nuclear Information System (INIS)

Karakaya, A.; Karakas, E.

2008-01-01

Permanent Magnet Synchronous Motors have nonlinear characteristics whose dynamics changes with time. In spite of this structure the permanent magnet synchronous motor has answered engineering problems in industry such as motion control which need high torque values. This paper obtains a nonlinear mathematical model for Permanent Magnet Synchronous Motor and realizes stimulation of the obtained model in the Matlab/Simulink program. Motor parameters are determined by an experimental set-up and they are used in the motor model. Speed control of motor model is made with Fuzzy Logic and Self Tuning logic PI controllers. Using the speed graphs obtained, rise time, overshoot, steady-state error and settling time are analyzed and controller performances are compared. (author)

Signs of abnormal motor performance in preschool children

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Martina Šlachtová

2013-12-01

Full Text Available BACKGROUND: The determination of the level of motor development should be a common part of examinations performed by paediatricians, physiotherapists and also teachers. The importance has been increasing because of the prevalence of developmental coordination disorder. OBJECTIVE: The aim of the study was to find the differences in performance of the selected motor tasks of gross motor function in preschoolers on both quantitative and qualitative parameters. METHODS: In the study 261 children were included, boys and girls aged 4–6 years (the average age 5.4 years attending regular kindergartens. We used motor tasks of standing on one leg and hopping. Significant differences in quantitative parameters were assessed by two-way ANOVA in Statistica (version 9 software. Relative frequency of characters in qualitative parameters was assessed by the test of the difference between two proportions. RESULTS: Significant differences between the age groups appeared in the quantitative parameters comparing 4 and 5 year old children and 4 and 6 year old children. Regardless of gender there were no differences between 5 year and 6 year old children. Overall, the girls mastered the tasks of the test better than the boys in the quantitative parameters of evaluation. From the evaluation of the quality of motor performance the most frequently reached performance in the tasks of the test has been described (relative frequency of characters. Significantly different motor performance from most children of the sample was observed particularly in the associated movements of limbs or trunk and face, showing for a reduced ability of selective relaxation at higher demands of the movement task. CONCLUSIONS: The different motor performance in observed parameters, showing for a reduced ability of selective relaxation, could be regarded as signs of abnormal motor performance in that age category.

Auditory and motor imagery modulate learning in music performance

Directory of Open Access Journals (Sweden)

Rachel M. Brown

2013-07-01

Full Text Available Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians’ encoding (during Learning, as they practiced novel melodies, and retrieval (during Recall of those melodies. Pianists learned melodies by listening without performing (auditory learning or performing without sound (motor learning; following Learning, pianists performed the melodies from memory with auditory feedback (Recall. During either Learning (Experiment 1 or Recall (Experiment 2, pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced and temporal regularity (variability of quarter-note interonset intervals were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists’ pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2. Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1: Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2: Higher auditory imagery skill predicted greater temporal regularity during Recall in the

Performance Comparison between a Permanent Magnet Synchronous Motor and an Induction Motor as a Traction Motor for High Speed Train

Science.gov (United States)

Kondo, Minoru; Kawamura, Junya; Terauchi, Nobuo

Performance tests are carried out to demonstrate the superiority of a permanent magnet synchronous motor to an induction motor as a traction motor for high-speed train. A prototype motor was manufactured by replacing the rotor of a conventional induction motor. The test results show that the permanent magnet motor is lighter, efficient and more silent than the induction motor because of the different rotor structure.

Assessment of global motor performance and gross and fine motor skills of infants attending day care centers.

Science.gov (United States)

Souza, Carolina T; Santos, Denise C C; Tolocka, Rute E; Baltieri, Letícia; Gibim, Nathália C; Habechian, Fernanda A P

2010-01-01

To analyze the global motor performance and the gross and fine motor skills of infants attending two public child care centers full-time. This was a longitudinal study that included 30 infants assessed at 12 and 17 months of age with the Motor Scale of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). This scale allows the analysis of global motor performance, fine and gross motor performance, and the discrepancy between them. The Wilcoxon test and Spearman's correlation coefficient were used. Most of the participants showed global motor performance within the normal range, but below the reference mean at 12 and 17 months, with 30% classified as having "suspected delays" in at least one of the assessments. Gross motor development was poorer than fine motor development at 12 and at 17 months of age, with great discrepancy between these two subtests in the second assessment. A clear individual variability was observed in fine motor skills, with weak linear correlation between the first and the second assessment of this subtest. A lower individual variability was found in the gross motor skills and global motor performance with positive moderate correlation between assessments. Considering both performance measurements obtained at 12 and 17 months of age, four infants were identified as having a "possible delay in motor development". The study showed the need for closer attention to the motor development of children who attend day care centers during the first 17 months of life, with special attention to gross motor skills (which are considered an integral part of the child's overall development) and to children with suspected delays in two consecutive assessments.

INDIVIDUAL CHARACTERISTICS OF THE STUDENTS ENROLLED IN DIFFERENT TYPES OF MOTOR ACTIVITY OF PHYSICAL EDUCATION

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E. M. Revenko

2017-01-01

Full Text Available The aim of this study was to examine intensity of motor and intellectual abilities and motivation for physical activity of students engaged in physical education in different sports groups.Methodology and research methods. Motor abilities of the students were assessed by measuring: hand, strength endurance, speed-power abilities, speed ability and general stamina. Assessment of general intelligence (GI was carried out by R. Amthauer’s test in the adaptation of L. A. Yasjukova. Formal-dynamic characteristics of the individuality (FDCI were studied using the technique of FDCI feedback form proposed by V. M. Rusalov. Assessment of motivation to implement motor activity was performed using the author's questionnaire. The method of statistical information processing has allowed the author to reveal correlation communications between motor abilities and GI of first-year students.Results. Significant differences in the manifestation of the individual students’ characteristics choosing practicing in different types of physical activity are experimentally established. In particular, students who chose table tennis, are inferior to the students who went in for wrestling in the manifestation of certain (power, motor skills, motivation for physical activity, but at the same time show relatively higher rates of certain intellectual abilities.Formal-dynamic traits of individuality are peculiar to students involved in table tennis, reflecting lower psychomotor activity (integrated indicator PDI - Psychomotor Development Index, in comparison with students who prefer fighting. The material presented provides a basis to argue that sports-oriented approach has some potential in the aspect of increase of efficiency of students’ physical education, distinguished by individual characteristics of age specific development.Scientific novelty. Scientific findings on distinct differences in motivation to physical activity, manifestation of motor and mental

Polyphasic Temporal Behavior of Finger-Tapping Performance: A Measure of Motor Skills and Fatigue.

Science.gov (United States)

Aydin, Leyla; Kiziltan, Erhan; Gundogan, Nimet Unay

2016-01-01

Successive voluntary motor movement involves a number of physiological mechanisms and may reflect motor skill development and neuromuscular fatigue. In this study, the temporal behavior of finger tapping was investigated in relation to motor skills and fatigue by using a long-term computer-based test. The finger-tapping performances of 29 healthy male volunteers were analyzed using linear and nonlinear regression models established for inter-tapping interval. The results suggest that finger-tapping performance exhibits a polyphasic nature, and has several characteristic time points, which may be directly related to muscle dynamics and energy consumption. In conclusion, we believe that future studies evaluating the polyphasic nature of the maximal voluntary movement will lead to the definition of objective scales that can be used in the follow up of some neuromuscular diseases, as well as, the determination of motor skills, individual ability, and peripheral fatigue through the use of a low cost, easy-to-use computer-based finger-tapping test.

Performance Characteristics of an Armature Voltage Controlled D.C. ...

African Journals Online (AJOL)

In this paper, the performance study of a separately excited d. c. motor whose speed is controlled by armature voltage variation is presented. Both the open loop and the closed loop steady state and transient characteristics are reported. The speed controllers considered in the closed loop mode are the proportional and the ...

MECHANICAL CHARACTERISTICS OF THREE-PHASE INDUCTION MOTORS WITH SINGLE-PHASE POWER SUPPLY

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V.S. Malyar

2016-06-01

Full Text Available Aim. Development of a method for calculating mechanical characteristics of three-phase induction motors with single-phase power supply. Methods. The developed algorithm is based on the high-adequacy mathematical model of motor and projection method for solving the boundary problem for equations of electrical circuits balance presented in the three-phase coordinate system. As a result of asymmetry of power supply to the stator windings, in steady state, flux-linkage and current change according to the periodic law. They are determined by solving the boundary problem. Results. The developed mathematical model allows determining periodic dependence of coordinates as a function of slip and, based on them, mechanical characteristics of motors. Academic novelty. The developed method relies on a completely new mathematical approach to calculation of stationary modes of nonlinear electromagnetic circuits, which allows obtaining periodic solution in a timeless domain. Practical value. Using the developed calculation algorithm, one can select capacitance required to start an induction motor with single-phase power supply and calculate static mechanical characteristics at a given capacitance.

Characteristics of switched reluctance motor operating in continuous and discontinuous conduction mode

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Ćalasan Martin P.

2013-01-01

Full Text Available This paper presents mechanical characteristics of Switched Reluctance Motor (SRM when it operates in Discontinuous Conduction Mode (DCM or in Continuous Conduction Mode (CCM, i.e. when the current through the phase coils (windings flows discontinuously or continuously. Firstly, in order to maximize the output power of SRM optimization of its control parameters was performed, such that the peak and RMS values of the current do not exceed the predefined values. The optimal control parameters vs. rotation speed, as well as the corresponding characteristics of torque, power and efficiency. It is shown that with CCM the machine torque (power, at high speed, can be increased.

Task-relevant cognitive and motor functions are prioritized during prolonged speed-accuracy motor task performance.

Science.gov (United States)

Solianik, Rima; Satas, Andrius; Mickeviciene, Dalia; Cekanauskaite, Agne; Valanciene, Dovile; Majauskiene, Daiva; Skurvydas, Albertas

2018-06-01

This study aimed to explore the effect of prolonged speed-accuracy motor task on the indicators of psychological, cognitive, psychomotor and motor function. Ten young men aged 21.1 ± 1.0 years performed a fast- and accurate-reaching movement task and a control task. Both tasks were performed for 2 h. Despite decreased motivation, and increased perception of effort as well as subjective feeling of fatigue, speed-accuracy motor task performance improved during the whole period of task execution. After the motor task, the increased working memory function and prefrontal cortex oxygenation at rest and during conflict detection, and the decreased efficiency of incorrect response inhibition and visuomotor tracking were observed. The speed-accuracy motor task increased the amplitude of motor-evoked potentials, while grip strength was not affected. These findings demonstrate that to sustain the performance of 2-h speed-accuracy task under conditions of self-reported fatigue, task-relevant functions are maintained or even improved, whereas less critical functions are impaired.

Dynamic Characteristics of DC Servo Motor Driven by Conventional Servo Driver: Estimation of Circuit Constants in Conventional Servo Driver

OpenAIRE

酒井, 史敏; 神谷, 好承; 関, 啓明; 疋津, 正利

2000-01-01

DC servo motors that are made as manufactured goods in the factory are widely used as actuators for driving many automatic machines. Then the manufactured driver (amplifier) that is matched to its servo motor is coveniently chosen to drive when aiming at high performance of the motion control. Motion of motor that is driven by the manufactured servo driver has very complicated dynamic characteristics. In this study, it is tried to make clear about inner composition of the servo driver through...

Depressive symptoms and motor performance in the elderly: a population based study Sintomas depressivos e desempenho motor em idosos: estudo de base populacional

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Kleyton T. Santos

2012-08-01

Full Text Available BACKGROUND: There is a growing incidence of depression in the elderly, and this impairment interferes directly in the reduction of motor skills. OBJECTVE: This study aims to examine the association between depressive symptoms and motor performance in community-dwelling elderly. METHOD: This is a cross-sectional study that analyzed data from 316 elders of a home and population-based epidemiological survey. The information used was: socio-demographic characteristics; motor performance tests; physical activity; and Geriatric Depression Scale. The data were analyzed using the Statistical Package for Social Sciences. Mann-Whitney U test, chi-square, Spearman correlation and Poisson regression, with a confidence interval of 95%, were calculated. RESULTS: For all motor tests, motor performance was negatively associated with depressive symptoms, regardless of gender, age, literacy and illiteracy, per capita income and physical activity. Elderly people with depressive symptoms have between 58% and 82% more functional limitation, depending on the motor performance test compared to those who were not depressed. CONCLUSIONS: There is an inverse relationship between depressive symptoms and motor performance in the elderly.CONTEXTUALIZAÇÃO: É crescente a ocorrência de depressão em idosos, e esse acometimento interfere diretamente na redução da capacidade motora. OBJETIVO: Analisar a associação entre sintomas depressivos e desempenho motor em idosos residentes na comunidade. MÉTODO: Trata-se de um estudo transversal que analisou dados de 316 idosos de uma pesquisa epidemiológica de base domiciliar e populacional. As informações usadas foram: características sociodemográficas; testes de desempenho motor; atividade física e Escala de Depressão Geriátrica. Os dados foram analisados no The Statistical Package for Social Sciences, sendo realizados testes U de Mann-Whitney, qui-quadrado, Correlação de Spearman e regressão de Poisson, com

Modulation of motor performance and motor learning by transcranial direct current stimulation.

Science.gov (United States)

Reis, Janine; Fritsch, Brita

2011-12-01

Transcranial direct current stimulation (tDCS) has shown preliminary success in improving motor performance and motor learning in healthy individuals, and restitution of motor deficits in stroke patients. This brief review highlights some recent work. Within the past years, behavioural studies have confirmed and specified the timing and polarity specific effects of tDCS on motor skill learning and motor adaptation. There is strong evidence that timely co-application of (hand/arm) training and anodal tDCS to the contralateral M1 can improve motor learning. Improvements in motor function as measured by clinical scores have been described for combined tDCS and training in stroke patients. For this purpose, electrode montages have been modified with respect to interhemispheric imbalance after brain injury. Cathodal tDCS applied to the unlesioned M1 or bihemispheric M1 stimulation appears to be well tolerated and useful to induce improvements in motor function. Mechanistic studies in humans and animals are discussed with regard to physiological motor learning. tDCS is well tolerated, easy to use and capable of inducing lasting improvements in motor function. This method holds promise for the rehabilitation of motor disabilities, although acute studies in patients with brain injury are so far lacking.

Calculation of static characteristics of linear step motors for control rod drives of nuclear reactors - an approximate approach

International Nuclear Information System (INIS)

Khan, S.H.; Ivanov, A.A.

1993-01-01

This paper describes an approximate method for calculating the static characteristics of linear step motors (LSM), being developed for control rod drives (CRD) in large nuclear reactors. The static characteristic of such an LSM which is given by the variation of electromagnetic force with armature displacement determines the motor performance in its standing and dynamic modes. The approximate method of calculation of these characteristics is based on the permeance analysis method applied to the phase magnetic circuit of LSM. This is a simple, fast and efficient analytical approach which gives satisfactory results for small stator currents and weak iron saturation, typical to the standing mode of operation of LSM. The method is validated by comparing theoretical results with experimental ones. (Author)

Comparative analysis of electro-mechanical characteristic of a three-phase induction motor with 1,5 CV with high performance and conventional one; Analise comparativa das caracteristicas eletromecanicas entre um motor de inducao trifasico de 1,5CV de alto-rendimento e convencional

Energy Technology Data Exchange (ETDEWEB)

Mendieta, J.C.V. [Dalkia, Rio de Janeiro, RJ (Brazil); Bertoleti, P.H.F.; Magalhaes Sobrinho, P. [Universidade Estadual Paulista (LAMOTRIZ/UNESP), Guaratingueta, SP (Brazil). Lab. de Otimizacao de Sistemas Motrizes Industriais; Souza, T.M. [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil)

2009-07-01

In Brazil, the electric power consumed by three-phase induction motors corresponding to approximately 55% of total electric power consumed by the industrial sector. Therefore, a thorough analysis of this type of engine under the questions of energy saving, economic viability and electro-mechanical characteristics are needed. This work deals with the comparative analysis for two motors three-phase induction, one conventional and another with high performance (manufacturer WEG and IP55 protection grade), aiming to obtain the necessary relationships to do an economical and electro-mechanical analysis.

Two-phase strategy of controlling motor coordination determined by task performance optimality.

Science.gov (United States)

Shimansky, Yury P; Rand, Miya K

2013-02-01

A quantitative model of optimal coordination between hand transport and grip aperture has been derived in our previous studies of reach-to-grasp movements without utilizing explicit knowledge of the optimality criterion or motor plant dynamics. The model's utility for experimental data analysis has been demonstrated. Here we show how to generalize this model for a broad class of reaching-type, goal-directed movements. The model allows for measuring the variability of motor coordination and studying its dependence on movement phase. The experimentally found characteristics of that dependence imply that execution noise is low and does not affect motor coordination significantly. From those characteristics it is inferred that the cost of neural computations required for information acquisition and processing is included in the criterion of task performance optimality as a function of precision demand for state estimation and decision making. The precision demand is an additional optimized control variable that regulates the amount of neurocomputational resources activated dynamically. It is shown that an optimal control strategy in this case comprises two different phases. During the initial phase, the cost of neural computations is significantly reduced at the expense of reducing the demand for their precision, which results in speed-accuracy tradeoff violation and significant inter-trial variability of motor coordination. During the final phase, neural computations and thus motor coordination are considerably more precise to reduce the cost of errors in making a contact with the target object. The generality of the optimal coordination model and the two-phase control strategy is illustrated on several diverse examples.

Statistical mechanical characteristics of slip-ring induction motors when direct current braking

Energy Technology Data Exchange (ETDEWEB)

Kedzior, W; Muchorowski, J; Pienkowski, K

1980-09-01

This paper evaluates methods of braking high capacity belt conveyors used in brown coal surface mines in Poland. Complications associated with belt conveyor braking, particularly when a conveyor moves down a slope, are analyzed. A method of calculating mechanical characteristics of wound-rotor induction motors during direct current braking taking into account saturation of magnetic circuit is presented. Characteristics of the SZUr motor with 630 kW power, used in brown coal mining, are also given. Analyses show that motor operation can be efficiently braked in two ways: 1. by changing additional resistance in rotor circuit (e.g. using thyristor controller); 2. by changing intensity of electric current supplied to stator winding (e.g. using a rectifier). (3 refs.) (In Polish)

User's Self-Prediction of Performance in Motor Imagery Brain-Computer Interface.

Science.gov (United States)

Ahn, Minkyu; Cho, Hohyun; Ahn, Sangtae; Jun, Sung C

2018-01-01

Performance variation is a critical issue in motor imagery brain-computer interface (MI-BCI), and various neurophysiological, psychological, and anatomical correlates have been reported in the literature. Although the main aim of such studies is to predict MI-BCI performance for the prescreening of poor performers, studies which focus on the user's sense of the motor imagery process and directly estimate MI-BCI performance through the user's self-prediction are lacking. In this study, we first test each user's self-prediction idea regarding motor imagery experimental datasets. Fifty-two subjects participated in a classical, two-class motor imagery experiment and were asked to evaluate their easiness with motor imagery and to predict their own MI-BCI performance. During the motor imagery experiment, an electroencephalogram (EEG) was recorded; however, no feedback on motor imagery was given to subjects. From EEG recordings, the offline classification accuracy was estimated and compared with several questionnaire scores of subjects, as well as with each subject's self-prediction of MI-BCI performance. The subjects' performance predictions during motor imagery task showed a high positive correlation ( r = 0.64, p performance even without feedback information. This implies that the human brain is an active learning system and, by self-experiencing the endogenous motor imagery process, it can sense and adopt the quality of the process. Thus, it is believed that users may be able to predict MI-BCI performance and results may contribute to a better understanding of low performance and advancing BCI.

Motor cortex synchronization influences the rhythm of motor performance in premanifest huntington's disease.

Science.gov (United States)

Casula, Elias P; Mayer, Isabella M S; Desikan, Mahalekshmi; Tabrizi, Sarah J; Rothwell, John C; Orth, Michael

2018-03-01

In Huntington's disease there is evidence of structural damage in the motor system, but it is still unclear how to link this to the behavioral disorder of movement. One feature of choreic movement is variable timing and coordination between sequences of actions. We postulate this results from desynchronization of neural activity in cortical motor areas. The objective of this study was to explore the ability to synchronize activity in a motor network using transcranial magnetic stimulation and to relate this to timing of motor performance. We examined synchronization in oscillatory activity of cortical motor areas in response to an external input produced by a pulse of transcranial magnetic stimulation. We combined this with EEG to compare the response of 16 presymptomatic Huntington's disease participants with 16 age-matched healthy volunteers to test whether the strength of synchronization relates to the variability of motor performance at the following 2 tasks: a grip force task and a speeded-tapping task. Phase synchronization in response to M1 stimulation was lower in Huntington's disease than healthy volunteers (P synchronization (r = -0.356; P synchronization and desynchronization could be a physiological basis for some key clinical features of Huntington's disease. © 2018 International Parkinson and Movement Disorder Society. © 2018 International Parkinson and Movement Disorder Society.

From Children to Adults: Motor Performance across the Life-Span

Science.gov (United States)

Leversen, Jonas S. R.; Haga, Monika; Sigmundsson, Hermundur

2012-01-01

The life-span approach to development provides a theoretical framework to examine the general principles of life-long development. This study aims to investigate motor performance across the life span. It also aims to investigate if the correlations between motor tasks increase with aging. A cross-sectional design was used to describe the effects of aging on motor performance across age groups representing individuals from childhood to young adult to old age. Five different motor tasks were used to study changes in motor performance within 338 participants (7–79 yrs). Results showed that motor performance increases from childhood (7–9) to young adulthood (19–25) and decreases from young adulthood (19–25) to old age (66–80). These results are mirroring results from cognitive research. Correlation increased with increasing age between two fine motor tasks and two gross motor tasks. We suggest that the findings might be explained, in part, by the structural changes that have been reported to occur in the developing and aging brain and that the theory of Neural Darwinism can be used as a framework to explain why these changes occur. PMID:22719958

Morphological and motor characteristics of Croatian first league female football players.

Science.gov (United States)

Jelaska, Petra Mandić; Katić, Ratko; Jelaska, Igor

2013-05-01

The aim of this study was to determine the structure of morphological and motor characteristics of Croatian first league female football players and their impact on the estimated quality of the players. According to the goal of the research, a sample consisted of 70 Croatian first league female football players. Participants were measured in 18 tests for assessing morphological characteristics, a set of 12 basic motor abilities tests and a set of 7 tests for assessing football-specific motor abilities. Exploratory factor analysis strategy was applied separately to all measured tests: morphological, basic motor abilities and football specific motor abilities. Factor analysis of morphological tests has shown existence of 3 significant latent dimensions that explain 64% of the total variability. Factors are defined as transverse dimensionality of the skeleton and voluminosity (35%), subcutaneous fat tissue (16%) and longitudinal dimensionality of the skeleton (13%). In the area of basic motor abilities, four factors were extracted. The first factor is responsible for the integration of agility and explosive power of legs, i.e. a factor of movement regulation (agility/lower body explosiveness) (23%), the second one defines muscle tone regulation (15%), the third one defines the frequency of leg movements (12%), while the fourth one is recognized as responsible for the manifestation of basic strength, particularly of basic core strength (19%). Two factors were isolated in the space of football-specific motor abilities: football-specific efficiency (53%) and situational football coordination (27%). Furthermore, by use of factor analysis on extracted latent dimensions (morphological, basic and football specific motor abilities) two higher order factors (explaining 87% of common variability) were extracted. They were named morphological-motor factor (54%) and football-specific motor abilities factor (33%). It is assumed that two extracted higher-order factors fully

Characteristics of a Bidirectional Rotary Ultrasonic Motor Using Obliquely Polarized Piezoelectric Transducers

Science.gov (United States)

Ishii, Takaaki; Ohnishi, Kazumasa; Ueha, Sadayuki

1993-05-01

Obliquely polarized piezoelectric ceramic transducers are newly employed to an ultrasonic motor. Since the direction of polarization is neither parallel nor perpendicular to the applied electric field, the longitudinal and the torsional vibrations are excited simultaneously. In addition, the direction of rotation can be switched by changing the driving frequency. Thus, this motor rotates in both clockwise and counterclockwise directions in spite of a single-phase input signal. The principle and the characteristics of the ultrasonic motor are described.

Dependence of the paired motor unit analysis on motor unit discharge characteristics in the human tibialis anterior muscle

Science.gov (United States)

Stephenson, Jennifer L.; Maluf, Katrina S.

2011-01-01

The paired motor unit analysis provides in vivo estimates of the magnitude of persistent inward currents (PIC) in human motoneurons by quantifying changes in the firing rate (ΔF) of an earlier recruited (reference) motor unit at the time of recruitment and derecruitment of a later recruited (test) motor unit. This study assessed the variability of ΔF estimates, and quantified the dependence of ΔF on the discharge characteristics of the motor units selected for analysis. ΔF was calculated for 158 pairs of motor units recorded from nine healthy individuals during repeated submaximal contractions of the tibialis anterior muscle. The mean (SD) ΔF was 3.7 (2.5) pps (range −4.2 to 8.9 pps). The median absolute difference in ΔF for the same motor unit pair across trials was 1.8 pps, and the minimal detectable change in ΔF required to exceed measurement error was 4.8 pps. ΔF was positively related to the amount of discharge rate modulation in the reference motor unit (r2=0.335; Precruitment of the reference and test motor units (r2=0.229, Pmotor unit activity (r2=0.110, Precruitment threshold of the test motor unit (r2=0.237, Pmotor unit analysis. PMID:21459110

Actual motor performance and self-perceived motor competence in children with attention-deficit hyperactivity disorder compared with healthy siblings and peers.

Science.gov (United States)

Fliers, Ellen A; de Hoog, Marieke L A; Franke, Barbara; Faraone, Stephen V; Rommelse, Nanda N J; Buitelaar, Jan K; Nijhuis-van der Sanden, Maria W G

2010-01-01

: Children with attention-deficit hyperactivity disorder (ADHD) frequently experience comorbid motor problems, developmental coordination disorder. Also, children with ADHD are said to overestimate their abilities in the cognitive and social domain, the so-called "Positive Illusory Bias." In this cross-sectional study, the relationship between actual motor performance and perceived motor competence was examined. Motor performance was assessed using the Movement Assessment Battery for Children in 100 children and adolescents (age 6-17 years), including 32 children with ADHD combined type, 18 unaffected siblings, and 50 healthy control children. ADHD was diagnosed using Parent and Teacher questionnaires and a clinical interview. Perceived motor competence and interest in the motor domain were rated with the Dutch supplement scale to Harters' Self-Perception Profile for Children, especially focusing on the motor domain (m-CBSK). Children with ADHD had poorer motor performance than unaffected siblings and control children, especially in the field of manual dexterity. However, no relationship was found between motor performance and perceived motor competence. Only children with the very lowest motor performance had a significantly lowered perception of their motor competence. Interest in the motor domain and motor self-perception was positively correlated. Children with ADHD performed poorer on the Movement Assessment Battery for Children, but generally overestimated their own motor competence.

Gross motor performance and self-perceived motor competence in children with emotional, behavioural, and pervasive developmental disorders: a review

NARCIS (Netherlands)

Emck, C.; Bosscher, R.J.; Beek, P.J.; Doreleijers, T.A.H.

2009-01-01

Aims: Motor performance and self-perceived motor competence have a great impact on the psychosocial development of children in general. In this review, empirical studies of gross motor performance and self-perception of motor competence in children with emotional (depression and anxiety),

Design, Modeling and Performance Optimization of a Novel Rotary Piezoelectric Motor

Science.gov (United States)

Duong, Khanh A.; Garcia, Ephrahim

1997-01-01

This work has demonstrated a proof of concept for a torsional inchworm type motor. The prototype motor has shown that piezoelectric stack actuators can be used for rotary inchworm motor. The discrete linear motion of piezoelectric stacks can be converted into rotary stepping motion. The stacks with its high force and displacement output are suitable actuators for use in piezoelectric motor. The designed motor is capable of delivering high torque and speed. Critical issues involving the design and operation of piezoelectric motors were studied. The tolerance between the contact shoes and the rotor has proved to be very critical to the performance of the motor. Based on the prototype motor, a waveform optimization scheme was proposed and implemented to improve the performance of the motor. The motor was successfully modeled in MATLAB. The model closely represents the behavior of the prototype motor. Using the motor model, the input waveforms were successfully optimized to improve the performance of the motor in term of speed, torque, power and precision. These optimized waveforms drastically improve the speed of the motor at different frequencies and loading conditions experimentally. The optimized waveforms also increase the level of precision of the motor. The use of the optimized waveform is a break-away from the traditional use of sinusoidal and square waves as the driving signals. This waveform optimization scheme can be applied to any inchworm motors to improve their performance. The prototype motor in this dissertation as a proof of concept was designed to be robust and large. Future motor can be designed much smaller and more efficient with lessons learned from the prototype motor.

An analytical method for the calculation of static characteristics of linear step motors for control rod drives in nuclear reactors

International Nuclear Information System (INIS)

Khan, S.H.; Ivanov, A.A.

1995-01-01

An analytical method for calculating static characteristics of linear dc step motors (LSM) is described. These multiphase passive-armature motors are now being developed for control rod drives (CRD) in large nuclear reactors. The static characteristics of such LSM is defined by the variation of electromagnetic force with armature displacement and it determines motor performance in its standing and dynamic modes of operation. The proposed analytical technique for calculating this characteristic is based on the permeance analysis method applied to phase magnetic circuits of LSM. Reluctances of various parts of phase magnetic circuit is calculated analytically by assuming probable flux paths and by taking into account complex nature of magnetic field distribution in it. For given armature positions stator and armature iron saturations are taken into account by an efficient iterative algorithm which gives fast convergence. The method is validated by comparing theoretical results with experimental ones which shows satisfactory agreement for small stator currents and weak iron saturation

Identifying patterns of motor performance, executive functioning, and verbal ability in preschool children: A latent profile analysis.

Science.gov (United States)

Houwen, Suzanne; Kamphorst, Erica; van der Veer, Gerda; Cantell, Marja

2018-04-30

A relationship between motor performance and cognitive functioning is increasingly being recognized. Yet, little is known about the precise nature of the relationship between both domains, especially in early childhood. To identify distinct constellations of motor performance, executive functioning (EF), and verbal ability in preschool aged children; and to explore how individual and contextual variables are related to profile membership. The sample consisted of 119 3- to 4-year old children (62 boys; 52%). The home based assessments consisted of a standardized motor test (Movement Assessment Battery for Children - 2), five performance-based EF tasks measuring inhibition and working memory, and the Receptive Vocabulary subtest from the Wechsler Preschool and Primary Scale of Intelligence Third Edition. Parents filled out the Behavior Rating Inventory of Executive Function - Preschool version. Latent profile analysis (LPA) was used to delineate profiles of motor performance, EF, and verbal ability. Chi-square statistics and multinomial logistic regression analysis were used to examine whether profile membership was predicted by age, gender, risk of motor coordination difficulties, ADHD symptomatology, language problems, and socioeconomic status (SES). LPA yielded three profiles with qualitatively distinct response patterns of motor performance, EF, and verbal ability. Quantitatively, the profiles showed most pronounced differences with regard to parent ratings and performance-based tests of EF, as well as verbal ability. Risk of motor coordination difficulties and ADHD symptomatology were associated with profile membership, whereas age, gender, language problems, and SES were not. Our results indicate that there are distinct subpopulations of children who show differential relations with regard to motor performance, EF, and verbal ability. The fact that we found both quantitative as well as qualitative differences between the three patterns of profiles underscores

CHARACTERISTICS OF A 4-PHASE VALVE RELUCTANCE MOTOR WHEN POWERED BY UNCAPACITOR SWITCHBOARD

Directory of Open Access Journals (Sweden)

V.B. Finkelshtein

2016-06-01

Full Text Available Purpose. Nowadays more and more in a variety of machines and mechanisms applied switched reluctance motor. When designing these engines solve the problem selection switch. While the switch scheme comprises symmetrical bridge and eight transistors, eight diodes; Miller switch comprises six transistors and six diodes; in company Graseby Controls Ltd switch circuit but four transistors and four diodes includes two capacitors. The aim is to develop a mathematical model, calculation program, a numerical analysis of the characteristics and parameters of the WFD and the characteristics of their work. Methodology. It is assumed that the resistance in the open state transistors and diodes for direct current is zero and the resistance of the transistors in the closed state, and diode reverse voltage is infinity. When feeding a single-phase motor and power at the same time two adjacent phases determined by the flow through the tooth. Results. The motor powered by a switch on the circuit symmetrical bridge power, which provides a maximum permissible winding temperature is 1.665 kW. But at the same time the surge up to 38.8%, resulting in high levels of noise and vibration. Through the installation of switching angles, ensuring reduction of torque ripple and reduce engine power to a level below which there is a decrease in the value of torque ripple, received power of 1,066 kW and a torque ripple value of 21.18 %. For engines with improved vibration acoustic characteristics necessary to use a switch of four transistors and four diodes. Practical value. For motors with improved vibration acoustic characteristics appropriate to apply uncapacitor switch on four transistors and four diodes, which allows you to receive half the value of torque ripple than the lowest value of the motor torque ripple, eating from a switch on the circuit asymmetric bridge. The cost of reluctance motor with uncapacitor switch on the circuit with four transistors and four diodes is

Quantitative assessment of finger motor performance: Normative data.

Directory of Open Access Journals (Sweden)

Alessio Signori

Full Text Available Finger opposition movements are the basis of many daily living activities and are essential in general for manipulating objects; an engineered glove quantitatively assessing motor performance during sequences of finger opposition movements has been shown to be useful to provide reliable measures of finger motor impairment, even subtle, in subjects affected by neurological diseases. However, the obtained behavioral parameters lack published reference values.To determine mean values for different motor behavioral parameters describing the strategy adopted by healthy people in performing repeated sequences of finger opposition movements, examining associations with gender and age.Normative values for finger motor performance parameters were obtained on a sample of 255 healthy volunteers executing sequences of finger-to-thumb opposition movements, stratified by gender and over a wide range of ages. Touch duration, inter-tapping interval, movement rate, correct sequences (%, movements in advance compared with a metronome (% and inter-hand interval were assessed.Increasing age resulted in decreased movement speed, advance movements with respect to a cue, correctness of sequences, and bimanual coordination. No significant performance differences were found between male and female subjects except for the duration of the finger touch, the interval between two successive touches and their ratio.We report age- and gender-specific normal mean values and ranges for different parameters objectively describing the performance of finger opposition movement sequences, which may serve as useful references for clinicians to identify possible deficits in subjects affected by diseases altering fine hand motor skills.

Principle and Basic Characteristics of a Hybrid Variable-Magnetic-Force Motor

Science.gov (United States)

Sakai, Kazuto; Kuramochi, Satoru

Reduction in the power consumed by motors is important for energy saving in the case of electrical appliances and electric vehicles (EVs). The motors used for operating these devices operate at variable speeds. Further, the motors operate with a small load in the stationary mode and a large load in the starting mode. A permanent magnet motor can be operated at the rated power with a high efficiency. However, the efficiency is low at a small load or at a high speed because the large constant magnetic force results in substantial core loss. Furthermore, the flux-weakening current that decreases the voltage at a high speed leads to significant copper loss and core loss. Therefore, we have developed a new technique for controlling the magnetic force of a permanent magnet on the basis of the load or speed of the motor. In this paper, we propose a novel motor that can vary the magnetic flux of a permanent magnet and clarify the principle and basic characteristics of the motor. The new motor has a permanent magnet that is magnetized by the magnetizing coil of the stator. The analysis results show that the magnetic flux linkage of the motor can be changed from 37% to 100% that a high torque can be produced.

Study on the Rollover Characteristic of In-Wheel-Motor-Driven Electric Vehicles Considering Road and Electromagnetic Excitation

OpenAIRE

Di Tan; Haitao Wang; Qiang Wang

2016-01-01

For in-wheel-motor-driven electric vehicles, the motor is installed in the wheel directly. Tyre runout and uneven load can cause magnet gap deformation in the motor, which will produce electromagnetic forces that further influence the vehicle rollover characteristics. To study the rollover characteristics, a verified 16-degree-of-freedom rollover dynamic model is introduced. Next, the vehicle rollover characteristics both with and without electromagnetic force are analyzed under conditions of...

Effect of Group Setting on Gross Motor Performance in Children 3-5 Years Old with Motor Delays.

Science.gov (United States)

Fay, Deanne; Wilkinson, Tawna; Wagoner, Michelle; Brooks, Danna; Quinn, Lauren; Turnell, Andrea

2017-02-01

The purpose of this study was to evaluate differences in gross motor performance of children 3-5 years of age with motor delays when assessed individually compared to assessment in a group setting among peers with typical development (TD). Twenty children with motor delays and 42 children with TD were recruited from a preschool program. A within-subject repeated measures design was used; each child with delay was tested both in an individual setting and in a group setting with two to four peers with TD. Testing sessions were completed 4-8 days apart. Ten different motor skills from the Peabody Developmental Motor Scales-2 were administered. Performance of each item was videotaped and scored by a blinded researcher. Overall gross motor performance was significantly different (p < .05) between the two settings, with 14 of 20 children demonstrating better performance in the group setting. In particular, children performed better on locomotion items (p < .05). The higher scores for locomotion in the group setting may be due to the influence of competition, motivation, or modeling. Assessing a child in a group setting is recommended as part of the evaluation process.

Motor-Enriched Learning Activities Can Improve Mathematical Performance in Preadolescent Children

Science.gov (United States)

Beck, Mikkel M.; Lind, Rune R.; Geertsen, Svend S.; Ritz, Christian; Lundbye-Jensen, Jesper; Wienecke, Jacob

2016-01-01

Objective: An emerging field of research indicates that physical activity can benefit cognitive functions and academic achievements in children. However, less is known about how academic achievements can benefit from specific types of motor activities (e.g., fine and gross) integrated into learning activities. Thus, the aim of this study was to investigate whether fine or gross motor activity integrated into math lessons (i.e., motor-enrichment) could improve children's mathematical performance. Methods: A 6-week within school cluster-randomized intervention study investigated the effects of motor-enriched mathematical teaching in Danish preadolescent children (n = 165, age = 7.5 ± 0.02 years). Three groups were included: a control group (CON), which received non-motor enriched conventional mathematical teaching, a fine motor math group (FMM) and a gross motor math group (GMM), which received mathematical teaching enriched with fine and gross motor activity, respectively. The children were tested before (T0), immediately after (T1) and 8 weeks after the intervention (T2). A standardized mathematical test (50 tasks) was used to evaluate mathematical performance. Furthermore, it was investigated whether motor-enriched math was accompanied by different effects in low and normal math performers. Additionally, the study investigated the potential contribution of cognitive functions and motor skills on mathematical performance. Results: All groups improved their mathematical performance from T0 to T1. However, from T0 to T1, the improvement was significantly greater in GMM compared to FMM (1.87 ± 0.71 correct answers) (p = 0.02). At T2 no significant differences in mathematical performance were observed. A subgroup analysis revealed that normal math-performers benefitted from GMM compared to both CON 1.78 ± 0.73 correct answers (p = 0.04) and FMM 2.14 ± 0.72 correct answers (p = 0.008). These effects were not observed in low math-performers. The effects were partly

Improving Motor and Drive System Performance – A Sourcebook for Industry

Energy Technology Data Exchange (ETDEWEB)

None

2014-02-01

This sourcebook outlines opportunities to improve motor and drive systems performance. The sourcebook is divided into four main sections: (1) Motor and Drive System Basics: Summarizes important terms, relationships, and system design considerations relating to motor and drive systems. (2) Performance Opportunity Road Map: Details the key components of well-functioning motor and drive systems and opportunities for energy performance opportunities. (3) Motor System Economics: Offers recommendations on how to propose improvement projects based on corporate priorities, efficiency gains, and financial payback periods. (4) Where to Find Help: Provides a directory of organizations associated with motors and drives, as well as resources for additional information, tools, software, videos, and training opportunities.

Effects of gross motor function and manual function levels on performance-based ADL motor skills of children with spastic cerebral palsy.

Science.gov (United States)

Park, Myoung-Ok

2017-02-01

[Purpose] The purpose of this study was to determine effects of Gross Motor Function Classification System and Manual Ability Classification System levels on performance-based motor skills of children with spastic cerebral palsy. [Subjects and Methods] Twenty-three children with cerebral palsy were included. The Assessment of Motor and Process Skills was used to evaluate performance-based motor skills in daily life. Gross motor function was assessed using Gross Motor Function Classification Systems, and manual function was measured using the Manual Ability Classification System. [Results] Motor skills in daily activities were significantly different on Gross Motor Function Classification System level and Manual Ability Classification System level. According to the results of multiple regression analysis, children categorized as Gross Motor Function Classification System level III scored lower in terms of performance based motor skills than Gross Motor Function Classification System level I children. Also, when analyzed with respect to Manual Ability Classification System level, level II was lower than level I, and level III was lower than level II in terms of performance based motor skills. [Conclusion] The results of this study indicate that performance-based motor skills differ among children categorized based on Gross Motor Function Classification System and Manual Ability Classification System levels of cerebral palsy.

Thermal Performance of Motor and Inverter in an Integrated Starter Generator System for a Hybrid Electric Vehicle

OpenAIRE

Sung Chul Kim

2013-01-01

If the integrated starter generator (ISG) motor and inverter operate under continuously high loading conditions, the system’s performance and durability will decrease and the heat dissipation requirements will increase. Therefore, in this study, we developed two cooling designs for the ISG motor and inverter, and then carried out both a model analysis and an experiment on the fluid flow and thermal characteristics of the system under various operating conditions. As the outdoor temperature in...

Dynamic neural networks based on-line identification and control of high performance motor drives

Science.gov (United States)

Rubaai, Ahmed; Kotaru, Raj

1995-01-01

In the automated and high-tech industries of the future, there wil be a need for high performance motor drives both in the low-power range and in the high-power range. To meet very straight demands of tracking and regulation in the two quadrants of operation, advanced control technologies are of a considerable interest and need to be developed. In response a dynamics learning control architecture is developed with simultaneous on-line identification and control. the feature of the proposed approach, to efficiently combine the dual task of system identification (learning) and adaptive control of nonlinear motor drives into a single operation is presented. This approach, therefore, not only adapts to uncertainties of the dynamic parameters of the motor drives but also learns about their inherent nonlinearities. In fact, most of the neural networks based adaptive control approaches in use have an identification phase entirely separate from the control phase. Because these approaches separate the identification and control modes, it is not possible to cope with dynamic changes in a controlled process. Extensive simulation studies have been conducted and good performance was observed. The robustness characteristics of neuro-controllers to perform efficiently in a noisy environment is also demonstrated. With this initial success, the principal investigator believes that the proposed approach with the suggested neural structure can be used successfully for the control of high performance motor drives. Two identification and control topologies based on the model reference adaptive control technique are used in this present analysis. No prior knowledge of load dynamics is assumed in either topology while the second topology also assumes no knowledge of the motor parameters.

Performance in complex motor tasks deteriorates in hyperthermic humans

DEFF Research Database (Denmark)

Piil, Jacob Feder; Lundbye-Jensen, Jesper; Trangmar, Steven J

2017-01-01

-motor tracking performance was reduced by 10.7 ± 6.5% following exercise-induced hyperthermia when integrated in the multipart protocol and 4.4 ± 5.7% when tested separately (bothP 1.3% (P math tasks...... of information or decision-making prior to responding. We hypothesized that divergences could relate to task complexity and developed a protocol consisting of 1) simple motor task [TARGET_pinch], 2) complex motor task [Visuo-motor tracking], 3) simple math task [MATH_type], 4) combined motor-math task [MATH...

Desempenho motor de lactentes frequentadores de berçários em creches públicas Motor performance of infants attending the nurseries of public day care centers

Directory of Open Access Journals (Sweden)

Letícia Baltieri

2010-09-01

cross-sectional study evaluated 40 infants (mean age 14.3±2.4 months attending public day care centers. The Bayley Scales of Infant and Toddler Development-III test was used to assess motor performance and to allow comparison between gross and fine domains of motor development. Neonatal, familial and day care center exposure data were collected and correlated with motor performance. Paired t-tests for mean comparisons and Pearson correlation were used. RESULTS: Motor performance of the studied group was below the average mean. The prevalence of suspected delays in gross and global motor performance was 22.5%, in contrast to none in fine motor performance. There was a significant difference between fine and gross motor performance, with the latter displaying lower scores; 35% of the group showed significant discrepancies between these areas. No correlation was found between the motor categories, neonatal and familial characteristics, and day care center exposure variables. CONCLUSIONS: The infants' global motor development fell below the average mean, with a delay in gross motor development and a relevant discrepancy between motor domains. This study suggests that attention should be given to gross motor skills and opportunities for exploration the environment in day care centers, especially during the first two years of life.

UNIFIED CONTROL STRUCTURE OF MULTI-TYPE INTERIOR PERMANENT MAGNET MOTOR

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M. NORHISAM

2015-03-01

Full Text Available This paper presents the control strategy structure to extract the speed torque characteristic for the newly designed three phase Multi Type Interior Permanent Magnet Motor. The proposed structure with the driving circuits exhibit the performance of torque characteristics of the stepper motor and brushless motor with independent coil winding per phase especially used as an in-wheel motor in agricultural applications. Brushless Direct Current motors exhibit characteristics of generating high torque at high speed while the Permanent Magnet Stepper motors has characteristic of generating high torque at low speed. The typical characteristics of the above two are integrated in the proposed structure with a complex control structure that handle the switching complexity and speed control in real time. Thus, a specially designed driving system is essential to drive and control this special motor. The evaluation of the motor mechanical characteristics when applying load torque is also presented. The result determines the practical torque range applicable for each motor configuration and as combined machine.

MEASURE CHARACTERISTICS OF MOTOR TESTS OF MOVEMENT FREQUENCY WITH STUDENT FROM MACEDONIA AND KOSOVO

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Georgi Georgiev

2014-06-01

Full Text Available Introduction: The tests of good measure characteristics are a multiple matter of interest. They can be property used in the work of selecting young athletes as well as programming the physical activities and giving marks in classes. There are many authors who have conducted researches and established measure characteristics of motor tests. Measure characteristics are constantly an actual issue for research. This research was conducted with the aim of establishing and comparing the measure characteristics of the used motor tests of movement frequencies with 11-year-old students from Macedonia and Kosovo. Methods: The sample of respondents consists of 180 male students at the age of 11 (100 from Macedonia and 80 from Kosovo. They were tested with three composite motor tests to assess the movement frequency. For the obtained data there calculated: basic descriptive parameters, Pearson coefficient of correlation, factor analyse, Cronbach α and Spearman-Brown’s coefficients (Vincent, 2005. Results: On the based of the received results, it is obvious that regarding the three tests satisfactory measure characteristics are established (validity and reliability. Discussion: In kinesiology, by using motor tests, we indirectly form a concept about the motor abilities of the respondents. That is why, it is of great importance to use tests that have satisfactory measure characteristics. The used tests are recommended for application in assessing motor abilities’ movement frequency. The final results correspond to a great extent with the researches of Metikos et al, (1989, Georgiev (1996, 2007, Pireva (2013 and other. References: Georgiev G (1996. Definiranje na stepenot na faktorskata validnost, relijabilnost i drugi merni karakteristiki vo biomotorniot prostor kaj učenicite od dvata pola od 11-godišna vozrast. (Magisterski trud, Univerzitet “Sv. Kiril i Metodij”, Fakultet za fizička kultura, Skopje. Georgiev G (2007. Sport i nauka, 5, 224

HEALTH INDICATORS IN SCHOOL: ASSESSMENT OF NUTRITIONAL STATUS AND MOTOR PERFORMANCE

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Andressa Ribeiro Contreira

2013-11-01

Full Text Available Objective: This study aimed to investigate the relationship among motor performance and nutritional status in students. Methods: Attended by 27 adolescents of both sexes, aged between 11-13 years (average 11.74 ± 0.70 years from a private school in Florianópolis/SC. The motor performance was assessed using the MABC-2. For assess the nutritional status was used the BMI calculus. Results: Among 27 participants, 6 had a risk / indicative of motor difficulties and 9 had overweight. The vast majority of participants had adequate height for age. There was negative significant statistically correlation, but moderate, among BMI and total performance in the MABC-2, indicating that as higher the BMI, worse is the motor performance. Conclusion: Based on these results and the literature, it is suggested that in addition to the identification of children with overweight and motor difficulties, programs targeted physical activity and motor interventions are implemented, especially in the school environment, aiming to maintain the health conditions.

PERFORMANCE OPTIMIZATION OF LINEAR INDUCTION MOTOR BY EDDY CURRENT AND FLUX DENSITY DISTRIBUTION ANALYSIS

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M. S. MANNA

2011-12-01

Full Text Available The development of electromagnetic devices as machines, transformers, heating devices confronts the engineers with several problems. For the design of an optimized geometry and the prediction of the operational behaviour an accurate knowledge of the dependencies of the field quantities inside the magnetic circuits is necessary. This paper provides the eddy current and core flux density distribution analysis in linear induction motor. Magnetic flux in the air gap of the Linear Induction Motor (LIM is reduced to various losses such as end effects, fringes, effect, skin effects etc. The finite element based software package COMSOL Multiphysics Inc. USA is used to get the reliable and accurate computational results for optimization the performance of Linear Induction Motor (LIM. The geometrical characteristics of LIM are varied to find the optimal point of thrust and minimum flux leakage during static and dynamic conditions.

A Recommended New Approach on Motorization Ratio Calculations of Stepper Motors

Science.gov (United States)

Nalbandian, Ruben; Blais, Thierry; Horth, Richard

2014-01-01

Stepper motors are widely used on most spacecraft mechanisms requiring repeatable and reliable performance. The unique detent torque characteristics of these type of motors makes them behave differently when subjected to low duty cycle excitations where the applied driving pulses are only energized for a fraction of the pulse duration. This phenomenon is even more pronounced in discrete permanent magnet stepper motors used in the space industry. While the inherent high detent properties of discrete permanent magnets provide desirable unpowered holding performance characteristics, it results in unique behavior especially in low duty cycles. Notably, the running torque reduces quickly to the unpowered holding torque when the duty cycle is reduced. The space industry's accepted methodology of calculating the Motorization Ratio (or Torque Margin) is more applicable to systems where the power is continuously applied to the motor coils like brushless DC motors where the cogging torques are low enough not to affect the linear performance of the motors as a function of applied current. This paper summarizes the theoretical and experimental studies performed on a number of space qualified motors under different pulse rates and duty cycles. It is the intention of this paper to introduce a new approach to calculate the Motorization Ratios for discrete permanent magnet steppers under all full and partial duty cycle regimes. The recommended approach defines two distinct relationships to calculate the Motorization Ratio for 100 percent duty cycle and partial duty cycle, when the motor detent (unpowered holding torque) is the main contributor to holding position. These two computations reflect accurately the stepper motor physical behavior as a function of the command phase (ON versus OFF times of the pulses), pointing out how the torque contributors combine. Important points highlighted under this study are the torque margin computations, in particular for well characterized

Identification and adaptive neural network control of a DC motor system with dead-zone characteristics.

Science.gov (United States)

Peng, Jinzhu; Dubay, Rickey

2011-10-01

In this paper, an adaptive control approach based on the neural networks is presented to control a DC motor system with dead-zone characteristics (DZC), where two neural networks are proposed to formulate the traditional identification and control approaches. First, a Wiener-type neural network (WNN) is proposed to identify the motor DZC, which formulates the Wiener model with a linear dynamic block in cascade with a nonlinear static gain. Second, a feedforward neural network is proposed to formulate the traditional PID controller, termed as PID-type neural network (PIDNN), which is then used to control and compensate for the DZC. In this way, the DC motor system with DZC is identified by the WNN identifier, which provides model information to the PIDNN controller in order to make it adaptive. Back-propagation algorithms are used to train both neural networks. Also, stability and convergence analysis are conducted using the Lyapunov theorem. Finally, experiments on the DC motor system demonstrated accurate identification and good compensation for dead-zone with improved control performance over the conventional PID control. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

MOTOR PERFORMANCE OF PRIMARY SCHOOL GIRLS ACCORDING TO BIRTH SEASON

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Josip Lepeš

2010-09-01

Full Text Available Body height, weight and motor performances data of 348 junior level primary schools girls 122 seven, 151 eight, 76 nine year olds. The results show that girls born in summer and in autumn generally had better performances in most of the skills, than those born in spring and winter and the differences were proved statistically in each case, expect obstacle race test. Girls who were better than average at some motor skills, generally outdid their school maters or contemporary group average at other motor skill performance as well.

Effects of gross motor function and manual function levels on performance-based ADL motor skills of children with spastic cerebral palsy

OpenAIRE

Park, Myoung-Ok

2017-01-01

[Purpose] The purpose of this study was to determine effects of Gross Motor Function Classification System and Manual Ability Classification System levels on performance-based motor skills of children with spastic cerebral palsy. [Subjects and Methods] Twenty-three children with cerebral palsy were included. The Assessment of Motor and Process Skills was used to evaluate performance-based motor skills in daily life. Gross motor function was assessed using Gross Motor Function Classification S...

QUALITY LEVEL-RELATED DIFFERENCES IN SELECTED MORPHOLOGICAL BODY CHARACTERISTICS AND MOTOR ABILITIES OF GOALKEEPERS IN TEAM HANDBALL

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Marko Šibila

2010-09-01

Full Text Available The aim of the present study is to identify the quality level-related differences between two groups of team handball goalkeepers in selected morphological body characteristics and motor abilities. A group of 36 senior goalkeepers who were members of first and second Slovenian handball league clubs (age: 22,6 ± 5,4 yr, height: 185,8 ± 4,7 cm, body weight: 88,7 ± 9,1 kg, training experience: 11,8 ± 4,8 yr participated in the present study. The goalkeepers were divided in two groups, according to their competition level. The sample of variables consisted of age and competition experience data, four morphological body characteristics and of six motor ability tests. In order to determine differences between two groups of goalkeepers in selected morphologic and motor variables a one–way analysis of variance (one-way ANOVA was employed. Findings of the present study indicate existing of quality level-related differences between two groups of team handball goalkeepers in selected morphological body characteristics and motor abilities. Further individualization and careful planning of training process of the goalkeepers is essential if we want to improve for goalkeepers’ important motor abilities and morphological body characteristics.

Permanently split capacitor motor-study of the design parameters

Science.gov (United States)

Sarac, Vasilija; Stefanov, Goce

2017-09-01

Paper analyzes the influence of various design parameters on torque of permanently split capacitor motor. Motor analytical model is derived and it is used for calculating the performance characteristics of basic motor model. The acquired analytical model is applied in optimization software that uses genetic algorithms (GA) as an optimization method. Optimized motor model with increased torque is derived by varying three motor parameters in GA program: winding turns ratio, average air gap flux density and motor stack length. Increase of torque has been achieved for nominal operation but also at motor starting. Accuracy of the derived models is verified by Simulink. The acquired values of several motor parameters from transient characteristics of Simulink models are compared with the corresponding values obtained from analytical models of both motors, basic and optimized. Numerical analysis, based on finite element method (FEM), is also performed for both motor models. As a result of the FEM analysis, magnetic flux density in motor cross-section is calculated and adequate conclusions are derived in relation to core saturation and air gap flux density in both motor models.

The Effect of Motor Performance on Sportive Performance of Children in Different Sports Branches

Science.gov (United States)

Aktug, Zait Burak; Iri, Ruckan

2018-01-01

The aim of the study is to investigate the relationship between motor performances of children aged 10-14 years and ball striking speeds made by specific technique and to determine motor performance differences between the branches. A total of 64 children (football = 22, volleyball = 19, tennis = 23) aged 10-14 years participated in the study. The…

Time of Day Does Not Modulate Improvements in Motor Performance following a Repetitive Ballistic Motor Training Task

Science.gov (United States)

Sale, Martin V.; Ridding, Michael C.; Nordstrom, Michael A.

2013-01-01

Repetitive performance of a task can result in learning. The neural mechanisms underpinning such use-dependent plasticity are influenced by several neuromodulators. Variations in neuromodulator levels may contribute to the variability in performance outcomes following training. Circulating levels of the neuromodulator cortisol change throughout the day. High cortisol levels inhibit neuroplasticity induced with a transcranial magnetic stimulation (TMS) paradigm that has similarities to use-dependent plasticity. The present study investigated whether performance changes following a motor training task are modulated by time of day and/or changes in endogenous cortisol levels. Motor training involving 30 minutes of repeated maximum left thumb abduction was undertaken by twenty-two participants twice, once in the morning (8 AM) and once in the evening (8 PM) on separate occasions. Saliva was assayed for cortisol concentration. Motor performance, quantified by measuring maximum left thumb abduction acceleration, significantly increased by 28% following training. Neuroplastic changes in corticomotor excitability of abductor pollicis brevis, quantified with TMS, increased significantly by 23% following training. Training-related motor performance improvements and neuroplasticity were unaffected by time of day and salivary cortisol concentration. Although similar neural elements and processes contribute to motor learning, training-induced neuroplasticity, and TMS-induced neuroplasticity, our findings suggest that the influence of time of day and cortisol differs for these three interventions. PMID:23577271

Time of Day Does Not Modulate Improvements in Motor Performance following a Repetitive Ballistic Motor Training Task

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Martin V. Sale

2013-01-01

Full Text Available Repetitive performance of a task can result in learning. The neural mechanisms underpinning such use-dependent plasticity are influenced by several neuromodulators. Variations in neuromodulator levels may contribute to the variability in performance outcomes following training. Circulating levels of the neuromodulator cortisol change throughout the day. High cortisol levels inhibit neuroplasticity induced with a transcranial magnetic stimulation (TMS paradigm that has similarities to use-dependent plasticity. The present study investigated whether performance changes following a motor training task are modulated by time of day and/or changes in endogenous cortisol levels. Motor training involving 30 minutes of repeated maximum left thumb abduction was undertaken by twenty-two participants twice, once in the morning (8 AM and once in the evening (8 PM on separate occasions. Saliva was assayed for cortisol concentration. Motor performance, quantified by measuring maximum left thumb abduction acceleration, significantly increased by 28% following training. Neuroplastic changes in corticomotor excitability of abductor pollicis brevis, quantified with TMS, increased significantly by 23% following training. Training-related motor performance improvements and neuroplasticity were unaffected by time of day and salivary cortisol concentration. Although similar neural elements and processes contribute to motor learning, training-induced neuroplasticity, and TMS-induced neuroplasticity, our findings suggest that the influence of time of day and cortisol differs for these three interventions.

Improvement in motor performance during high pressure pump starting at NDDP, Kalpakkam

International Nuclear Information System (INIS)

Nagaraj, R.; Murugan, V.; Thalor, K.L.; Saxena, A.K.; Dangore, A.Y.; Prabhakar, S.; Tiwari, P.K.

2007-01-01

The major energy requirement required for a Sea Water Reverse Osmosis is in the form of Electrical Energy. The primary energy requirement in the process is the electrical energy fed to High Pressure Pumps to pressurize the feed sea water to membranes. This High pressure pump being a high inertia load requires very high torque at the time of starting. This high starting torque requirement results in increased acceleration time of the motor which subsequently increases the strain on the upstream electrical system from motor feeder to transformer. Such starting characteristic necessitates provision of special starting scheme for the high pressure pump motors. Sea water reverse osmosis (SWRO) plant of Nuclear Desalination Demonstration Project (NDDP) was commissioned in October 2002 at Kalpakkam, India. This paper presents the experiences of problems faced due to the typical starting characteristics of High Pressure pumps and provision of series reactor type motor starter for the same. (author)

Prevalence of obesity and motor performance capabilities in Tyrolean preschool children.

Science.gov (United States)

Greier, Klaus; Riechelmann, Herbert; Burtscher, Martin

2014-07-01

The childrens' world of movement has changed dramatically during the last decades. As a consequence motor performance decreases particularly in children affected by overweight and obesity. This study analyses the influence of the body mass index (BMI) on motor performance of pre-school children. In a cross-sectional study including 41 kindergartens in Tyrol (Austria), 4- to 5-year-old children (n = 1,063) were recruited. Four BMI groups were used according to a German BMI reference system: Group I (anorexic/underweight), group II (normal weight), group III (overweight) and group IV (obese). Motor performance was assessed by the use of the Karlsruhe Motorik-Screening (KMS 3-6). Out of the 1,063 preschool children (550 ♂, 513 ♀) 7.6 % (n = 81) were overweight and 5.5 % (n = 58) were obese. The results demonstrate that motor performance of under- and overweight preschool-children is not different from children with normal BMI, but obese children had significantly lower motor performance (p obese Tyrolean preschool children is similar to those of non-mountainous areas of Austria and Germany. The fact that motor performance is reduced only in obese children suggests that targeted promotion of physical activity is urgently needed for preschool children particularly considering children with a risk to develop obesity. Besides the efforts of parents, nursery schools are the ideal setting for intervention measures.

Space shuttle booster separation motor design

Science.gov (United States)

Smith, G. W.; Chase, C. A.

1976-01-01

The separation characteristics of the space shuttle solid rocket boosters (SRBs) are introduced along with the system level requirements for the booster separation motors (BSMs). These system requirements are then translated into specific motor requirements that control the design of the BSM. Each motor component is discussed including its geometry, material selection, and fabrication process. Also discussed is the propellant selection, grain design, and performance capabilities of the motor. The upcoming test program to develop and qualify the motor is outlined.

Motor performance and physical activity habits of college students in Costa Rica

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Judith Jiménez-Díaz

2016-01-01

Full Text Available The purpose of this study was to analyze the motor performance of fundamental motor skills and physical activity habits of students at the University of Costa Rica. A total of 92 males and 48 females (M age = 19.78 yr., SD = 4.72 yr. enrolled in different Sports Activity courses taught at the Rodrigo Facio campus was assessed. The Instrument for the Evaluation of Fundamental Movement Patterns was used to assess motor performance in eight fundamental movement patterns (running, jumping, galloping, catching, throwing, bouncing, and kicking. The physical activity level was obtained from a self-reported questionnaire developed for such purpose. Results show that 28% of the participants were physically active. Participants presented a proficient performance in kicking, running, and galloping, but a non-proficient performance in jumping, hopping, bouncing, throwing and catching. Physical activity behavior was related to the overall performance of the motor skills assessed (Rho = .233; p = .006. In conclusion, college students presented a proficient performance on three of the eight skills assessed. In addition, a relationship was found between physical activity levels and performance. Physical Education teachers are recommended to develop activities to enhance motor performance of fundamental motor skills in college students.

Anthropometric and motor performance profile of elite futsal athletes

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Ademar Avelar

2008-07-01

Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n1p76 The purpose of the present study was to identify the anthropometric and motor performance profi le of futsal (indoor soccer athletes in the second and third-placed teams in the Parana state championships (Brazil. Anthropometric(body mass, stature and skinfolds thickness and motor performance (modified abdominal test, shuttle run, race of 30 m and 40 s measures were obtained from twenty-seven male athletes (24.7 ± 6.4 years; 73.6 ± 7.6 kg; 174.8 ± 6.6 cm. For data analysis, athletes were grouped according to game positions. ANOVA one-way was used for comparisons between different positions, followed by Scheffé’s post hoc test, with p < 0.05. Signifi cant differences were detected in body mass (midfielder < goalkeeper, p < 0.01, stature (midfielder < forward and goalkeeper, p < 0.01 and lean body mass (midfi elder < goalkeeper, p < 0.01. No significant differences in motor performance were detected between the athletes studied. The results of this study show that futsal athletes playing in different positions exhibit similar anthropometric and motor performance, in the majority of variables.

The validity of parental reports on motor skills performance level in preschool children: a comparison with a standardized motor test.

Science.gov (United States)

Zysset, Annina E; Kakebeeke, Tanja H; Messerli-Bürgy, Nadine; Meyer, Andrea H; Stülb, Kerstin; Leeger-Aschmann, Claudia S; Schmutz, Einat A; Arhab, Amar; Ferrazzini, Valentina; Kriemler, Susi; Munsch, Simone; Puder, Jardena J; Jenni, Oskar G

2018-05-01

Motor skills are interrelated with essential domains of childhood such as cognitive and social development. Thus, the evaluation of motor skills and the identification of atypical or delayed motor development is crucial in pediatric practice (e.g., during well-child visits). Parental reports on motor skills may serve as possible indicators to decide whether further assessment of a child is necessary or not. We compared parental reports on fundamental motor skills performance level (e.g., hopping, throwing), based on questions frequently asked in pediatric practice, with a standardized motor test in 389 children (46.5% girls/53.5% boys, M age = 3.8 years, SD = 0.5, range 3.0-5.0 years) from the Swiss Preschoolers' Health Study (SPLASHY). Motor skills were examined using the Zurich Neuromotor Assessment 3-5 (ZNA3-5), and parents filled in an online questionnaire on fundamental motor skills performance level. The results showed that the answers from the parental report correlated only weakly with the objectively assessed motor skills (r = .225, p skills would be desirable, the parent's report used in this study was not a valid indicator for children's fundamental motor skills. Thus, we may recommend to objectively examine motor skills in clinical practice and not to exclusively rely on parental report. What is Known: • Early assessment of motor skills in preschool children is important because motor skills are essential for the engagement in social activities and the development of cognitive abilities. Atypical or delayed motor development can be an indicator for different developmental needs or disorders. • Pediatricians frequently ask parents about the motor competences of their child during well-child visits. What is New: • The parental report on fundamental motor skills performance level used in this study was not a reliable indicator for describing motor development in the preschool age. • Standardized examinations of motor skills are

Relationship of ocular accommodation and motor skills performance in developmental coordination disorder.

Science.gov (United States)

Rafique, Sara A; Northway, Nadia

2015-08-01

Ocular accommodation provides a well-focussed image, feedback for accurate eye movement control, and cues for depth perception. To accurately perform visually guided motor tasks, integration of ocular motor systems is essential. Children with motor coordination impairment are established to be at higher risk of accommodation anomalies. The aim of the present study was to examine the relationship between ocular accommodation and motor tasks, which are often overlooked, in order to better understand the problems experienced by children with motor coordination impairment. Visual function, gross and fine motor skills were assessed in children with developmental coordination disorder (DCD) and typically developing control children. Children with DCD had significantly poorer accommodation facility and amplitude dynamics compared to controls. Results indicate a relationship between impaired accommodation and motor skills. Specifically, accommodation anomalies correlated with visual motor, upper limb and fine dexterity task performance. Consequently, we argue accommodation anomalies influence the ineffective coordination of action and perception in DCD. Furthermore, reading disabilities were related to poorer motor performance. We postulate the role of the fastigial nucleus as a common pathway for accommodation and motor deficits. Implications of the findings and recommended visual screening protocols are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Operation Characteristics Optimization of Low Power Three-Phase Asynchronous Motors

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VLAD, I.

2014-02-01

Full Text Available Most published papers on low power asynchronous motors were aimed to achieve better operational performances in different operating conditions. The optimal design of the general-purpose motors requires searching and selecting an electric machine to meet minimum operating costs criterion and certain customer imposed restrictive conditions. In this paper, there are many significant simulations providing qualitative and quantitative information on reducing active and reactive energy losses in motors, and on parameters and constructive solution. The optimization study applied the minimal operating costs criterion, and it took into account the starting restrictive conditions. Thirteen variables regarding electromagnetic stresses and main constructive dimensions were considered. The operating costs of the optimized motor decreased with 25.6%, as compared to the existing solution. This paper can be a practical and theoretical support for the development and implementation of modern design methods, based on theoretical and experimental study of stationary and transient processes in low power motors, to increase efficiency and power factor.

ANTHROPOMETRIC AND MOTOR CHARACTERISTICS IN VOLLEYBALL AND BASKETBALL PLAYERS

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Enver Tahiraj

2011-09-01

Full Text Available The purpose of this study is the morphological and motor status players for both teams, and then based on the results of anthropometric and motor status of this work can also do a comparative analysis between these two sports, volleyball and basketball. Therefore, the present study is in the results (achieved of the differences and their special achievement and to skills top players. In this research, we have participation 30 players (15 for each team volleyball and basketball, the teams is from Pristina. It should be noted that all players are fully able to follow regular exercise in their clubs. Those two clubs in Pristina, have the training five days a week, the clubs are in super league and the current champion in country. We as a coach interesed about the comparisons and differences of these two sports for anthropometric and motor characteristics, and in these sports, in those two sports players have a special that is characterized by height body and explosive power. We think, that this research work serves as a continuation of the way and further research on these two sports that have a significant increase from the psycho-physical and anthropometric aspects

Learning-performance distinction and memory processes for motor skills: a focused review and perspective.

Science.gov (United States)

Kantak, Shailesh S; Winstein, Carolee J

2012-03-01

Behavioral research in cognitive psychology provides evidence for an important distinction between immediate performance that accompanies practice and long-term performance that reflects the relative permanence in the capability for the practiced skill (i.e. learning). This learning-performance distinction is strikingly evident when challenging practice conditions may impair practice performance, but enhance long-term retention of motor skills. A review of motor learning studies with a specific focus on comparing differences in performance between that at the end of practice and at delayed retention suggests that the delayed retention or transfer performance is a better indicator of motor learning than the performance at (or end of) practice. This provides objective evidence for the learning-performance distinction. This behavioral evidence coupled with an understanding of the motor memory processes of encoding, consolidation and retrieval may provide insight into the putative mechanism that implements the learning-performance distinction. Here, we propose a simplistic empirically-based framework--motor behavior-memory framework--that integrates the temporal evolution of motor memory processes with the time course of practice and delayed retention frequently used in behavioral motor learning paradigms. In the context of the proposed framework, recent research has used noninvasive brain stimulation to decipher the role of each motor memory process, and specific cortical brain regions engaged in motor performance and learning. Such findings provide beginning insights into the relationship between the time course of practice-induced performance changes and motor memory processes. This in turn has promising implications for future research and practical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

Thermal Performance of Motor and Inverter in an Integrated Starter Generator System for a Hybrid Electric Vehicle

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Sung Chul Kim

2013-11-01

Full Text Available If the integrated starter generator (ISG motor and inverter operate under continuously high loading conditions, the system’s performance and durability will decrease and the heat dissipation requirements will increase. Therefore, in this study, we developed two cooling designs for the ISG motor and inverter, and then carried out both a model analysis and an experiment on the fluid flow and thermal characteristics of the system under various operating conditions. As the outdoor temperature increased from 25 °C to 95 °C, the coil temperature of the air-cooled motor increased by about 82 °C. Under the harsh-air condition of 95 °C, the coil of the air-cooled motor increased to a maximum temperature of about 158.5 °C. We also determined that the temperature of the metal-oxide-semiconductor field-effect transistor (MOSFET chip in the liquid-cooled inverter increased to a maximum temperature of about 96.8 °C under a coolant flow rate of 4 L/min and a coolant temperature of 65 °C. The observed thermal performance of the ISG motor and inverter using the proposed cooling structures was found to be sufficient for heat loads under various real driving conditions for a hybrid electric vehicle (HEV.

Stepping motors a guide to theory and practice

CERN Document Server

Acarnely, Paul

2002-01-01

This book provides an introductory text which will enable the reader to both appreciate the essential characteristics of stepping motor systems and understand how these characteristics are being exploited in the continuing development of new motors, drives and controllers. A basic theoretical approach relating to the more significant aspects of performance is presented, although it is assumed throughout that the reader has no previous experience of electrical machines and is primarily interested in the applications of stepping motors.

Numerical studies on the force characteristic of superconducting linear synchronous motor with HTS bulk magnet

Science.gov (United States)

Tang, Junjie; Li, Jing; Li, Xiang; Han, Le

2018-03-01

High temperature superconductor (HTS) bulks have significant potential use in linear motor application act as quasi-permanent magnet to replace traditional magnets. Force characteristic between HTS bulk magnet and traveling magnetic field was investigated with numerical simulation and experimental measurement in this paper. Influences of bulk height and number on the force characteristic were studied by the finite element model considering the nonlinear E-J relationship. Study was also made on addition of a back iron plate to the bulk magnet. Besides, force characteristic of bulk was compared with the permanent magnet results. The small initial decrease of the thrust could be explained by inside superconducting current redistribution. It was found that efficiency of linear motor did not increase by adding more bulk magnets. The bulk magnet will be remagnetized instead of erasing trapped field with the increase of the traveling magnetic field strength. The conclusions are helpful in prediction and design the linear motor with HTS bulk magnet.

Motor Performance in Relation with Sustained Attention in Children with Attention Deficit Hyperactivity Disorder

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Solmaz Solouki

2012-04-01

Full Text Available Objective: Present study compares relationship between motor performance, sustained attention and impulse control in children with Attention Deficit Hyperactivity Disorder and normal children. Materials & Methods: In this descriptive-analytic study, 21 boys with ADHD and 21 normal boys in the age range of 7- 10 years old were participated. Motor performance by using Bruininks Oseretsky Test of Motor Proficiency and sustained attention and impulse control by using Continuous Performance Test were evaluated. Results: Analysis by T-Test and Mann-Whitney revealed significant difference between ADHD group and normal group in gross, fine and battery motor performance also sustained attention and impulse control (P<0.0001. Analysis by Z-Fisher test indicated no significant difference between Correlation Coefficient of inattention and gross motor performance in two groups (P=0.276 but significant difference between Correlation Coefficient of inattention and fine (P<0.0001 and battery (P<0.0001 motor performance were shown. Correlation Coefficient impulsivity and gross (P=0.379, fine (P=0.92 and battery (P=0.562 motor performance shown no significant difference between two groups. Conclusion: According to study results there was a positive relation between sustained attention and impulse control and most of motor performance in both groups. Therefore these findings help Occupational Therapist to determine rehabilitation priorities and to use exact strategies in order to enhance motor performance in children.

Development of High-Speed Switched Reluctance Motor for Electric Power Tools

Science.gov (United States)

Nakamura, Kenji; Kumasaka, Yuya; Ichinokura, Osamu

2017-10-01

This paper presents design and experimental evaluation of a switched reluctance (SR) motor used for electric power tools. First, characteristics of a previous designed 6/4-pole SR motor is shown and compared to a permanent magnet (PM) motor used in present electric power tools. Next, to further improve characteristics, a 12/8-pole SR motor is designed and evaluated in experiment. It is proved that the performance of the prototype 12/8-pole SR motor is almost comparable or superior to the present PM motor.

Motor performance of pupils with attention deficit hyperactivity disorder (ADHD).

OpenAIRE

Otipková, Zuzana

2012-01-01

Title: Motor performance of pupils with attention deficit hyperactivity disorder (ADHD). Objectives: The aim of the work was to determine the level of fine and gross motor skills of upper extremities of the pupils with diagnosis ADHD at schools specialized on these pupils and compare it with the fine and gross motor skills of upper extremities of children without this diagnosis at common elementary school. Further work objective was to determine the level of gross motor skills of lower limbs ...

The design, characteristic experiment of rotary step motor for ball screw type CEDM

International Nuclear Information System (INIS)

Hu, H.; Yoo, J. Y.; Kim, J. H.; Kim, J. I.; Yeo, J. W.

2003-01-01

This paper describes the 3-dimensional finite element analysis(FEA) for the design of rotary step motor(RSM) for ball screw-type Control Element Drive Mechanism(CEDM) and compares with the holding torque characteristics of prototype RSM. A thermal analysis was performed for the RSM. A model for the thermal analysis of the electromagnet was developed and theoretical bases for the model were established. It is important that the temperature of the RSM windings be maintained within the allowable limit of the insulation, since the electromagnet of CEDM is always supplied with current during the reactor operation. So the thermal analysis of the winding insulation which is composed of polyimide and air were performed by finite element method. But the test results show that the holding; torque is less than those by analysis

Evaluation and prediction of the performance of positive displacement motor

Energy Technology Data Exchange (ETDEWEB)

Tudor, R.; Ginzburg, L. [Canadian Fracmaster Ltd., Calgary, AB (Canada); Xu, H. [Japan National Oil Corp (Japan); Li, J.; Robello, G.; Grigor, C.

1998-12-31

Test results of positive displacement motors (PDMs) collected by using various PDMs from a number of different suppliers have been analyzed. Various correlations have been developed and motor performance pumped with incompressible drilling fluid was evaluated based on test data provided by suppliers in the form of pressure drop versus torque output. Conclusions drawn from the study suggest that when a motor is operated at less than full load, the correlation between mechanical power and hydraulic power across the PDM power section can be described with a simple linear equation (different for each PDM type). Assuming the availability of patented geometric information for each PDM type, the performance of PDMs can be described by both the geometric parameters of the motor and the rheological properties of the circulation fluid. 9 refs., 8 figs.

Working Memory Training Improves Dual-Task Performance on Motor Tasks.

Science.gov (United States)

Kimura, Takehide; Kaneko, Fuminari; Nagahata, Keita; Shibata, Eriko; Aoki, Nobuhiro

2017-01-01

The authors investigated whether working memory training improves motor-motor dual-task performance consisted of upper and lower limb tasks. The upper limb task was a simple reaction task and the lower limb task was an isometric knee extension task. 45 participants (age = 21.8 ± 1.6 years) were classified into a working memory training group (WM-TRG), dual-task training group, or control group. The training duration was 2 weeks (15 min, 4 times/week). Our results indicated that working memory capacity increased significantly only in the WM-TRG. Dual-task performance improved in the WM-TRG and dual-task training group. Our study provides the novel insight that working memory training improves dual-task performance without specific training on the target motor task.

High frequency vibration characteristics of electric wheel system under in-wheel motor torque ripple

Science.gov (United States)

Mao, Yu; Zuo, Shuguang; Wu, Xudong; Duan, Xianglei

2017-07-01

With the introduction of in-wheel motor, the electric wheel system encounters new vibration problems brought by motor torque ripple excitation. In order to analyze new vibration characteristics of electric wheel system, torque ripple of in-wheel motor based on motor module and vector control system is primarily analyzed, and frequency/order features of the torque ripple are discussed. Then quarter vehicle-electric wheel system (QV-EWS) dynamics model based on the rigid ring tire assumption is established and the main parameters of the model are identified according to tire free modal test. Modal characteristics of the model are further analyzed. The analysis indicates that torque excitation of in-wheel motor is prone to arouse horizontal vibration, in which in-phase rotational, anti-phase rotational and horizontal translational modes of electric wheel system mainly participate. Based on the model, vibration responses of the QV-EWS under torque ripple are simulated. The results show that unlike vertical low frequency (lower than 20 Hz) vibration excited by road roughness, broadband torque ripple will arouse horizontal high frequency (50-100 Hz) vibration of electric wheel system due to participation of the three aforementioned modes. To verify the theoretical analysis, the bench experiment of electric wheel system is conducted and vibration responses are acquired. The experiment demonstrates the high frequency vibration phenomenon of electric wheel system and the measured order features as well as main resonant frequencies agree with simulation results. Through theoretical modeling, analysis and experiments this paper reveals and explains the high frequency vibration characteristics of electric wheel system, providing references for the dynamic analysis, optimal design of QV-EWS.

A fuzzy expert system for predicting the performance of switched reluctance motor

International Nuclear Information System (INIS)

Mirzaeian, B.; Moallem, M.; Lucas, Caro

2001-01-01

In this paper a fuzzy expert system for predicting the performance of a switched reluctance motor has been developed. The design vector consists of design parameters, and output performance variables are efficiency and torque ripple. An accurate analysis program based on Improved Magnetic Equivalent Circuit method has been used to generate the input-output data. These input-output data is used to produce the initial fuzzy rules for predicting the performance of Switched Reluctance Motor. The initial set of fuzzy rules with triangular membership functions has been devised using a table look-up scheme. The initial fuzzy rules have been optimized to a set of fuzzy rules with Gaussian membership functions using gradient descent training scheme. The performance prediction results for a 6/8, 4 kw, Switched Reluctance Motor shows good agreement with the results obtained from Improved Magnetic Equivalent Circuit method or Finite Element analysis. The developed fuzzy expert system can be used for fast prediction of motor performance in the optimal design process or on-line control schemes of Switched Reluctance motor

Anthropometric characteristics and motor abilities in 13-15 year old female volleyball players

OpenAIRE

Nešić, Goran; Majstorović, Nikola; Sikimić, Milan; Marković, Srđan; Ilić, Dejan; Grbić, Vladimir; Osmankač, Nedžad; Savić, Zoran

2014-01-01

The goal of this research was to determine whether there is a difference in the manifestation of measured anthropometric characteristics and tested motor abilities of female volleyball players that are 13-15 years old. The sample of participants consists of 62 female volleyball players divided into three groups according to their age. The sample of variables has two sub-samples: 18 variables belonging to anthropometric space and 14 variables belonging to the space of motor skills. A variance ...

CANONICAL CORRELATION OF MORPHOLOGIC CHARACTERISTIC AND MOTORIC ABILITIES OF YOUNG JUDO ATHLETES

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Lulzim Ibri

2013-07-01

Full Text Available In sample from 80 young judo athletes aged from 16-17 year, was applied the system a total of 18 variables, of which 10 are morphologic characteristic and 8 motoric abilities variables, with a purpose to determinate mutual report between each other, while the information were analyzed by using canonical correlation analysis. With case of authentication statistically important relation was achieve one pair of canonical correlations statistically important. In morphologic variables field the canonical factor is interpreted in first canonical structure is the consists of variables: adipose tissue under skin of stomach (ATST, adipose tissue under skin of triceps (ATTR, adipose tissue under skin of biceps (ATBI, adipose tissue under skin of sub scapulars (ATSS, adipose tissue under skin of sub iliac a (ATSI and adipose tissue under skin of list (ATSL, so that is interpreted as a canonical factor of adipose tissue: And second structure of canonical factors of anthropometric characteristics is the consists of variables: body length: body length (LEBO, length of the leg (LELE and length of the arm (LEAR, so that is interpreted as a canonical factor of longitudinal dimensionality. The first structure of canonical factors in motoric variables is can not be interpreted because of low values of motor variables, while second structure of canonical factors of motoric abilities is the consists of variables: squeeze palm (SQPA, so that is interpreted as a canonical factor of strong factor in palm. Based on structure analysis of matrix results of canonical factors results were shown that to young judo athletes of this age exist statistically valid correlations between canonical factor of anthropometric variables and canonical factor of variables to motoric abilities which is (Rc=77 that is statistically valid in level (P=00.

Factors associated with motor performance among overweight and nonoverweight Tyrolean primary school children.

Science.gov (United States)

Ruedl, Gerhard; Greier, Klaus; Kirschner, Werner; Kopp, Martin

2016-01-01

The increasing prevalence of overweight and obesity among children is often associated with motor deficits. Motor performance among children partly depends on modifiable factors, for example, weight status, electronic media use, sports club participation, and on nonmodifiable factors, for example, sex, age, migration background, or socio-economic status. To evaluate factors associated with motor performance among overweight and nonoverweight Tyrolean primary school children. Height, weight, and sport motor performance of primary school children were measured using the German motor performance test DMT 6-18. In addition, children were asked about migration background, sports club participation, and electronic media use in their room. A total of 304 children (48.7% girls) with a mean age of 8.0 ± 1.2 years were tested. In total, 61 (20.1%) children were overweight or obese. Regarding motor performance, nonoverweight children showed significantly higher total z-scores (106.8 ± 5.7 vs. 102.4 ± 6.8). For the total cohort, results of the multiple linear regression analysis (R (2) = 0.20) revealed that factors male sex (β = 0.12), nonoverweight children (β = 0.28), higher school grade (β = 0.23), sports club participation (β = 0.18),and > 2 weekly lessons of physical education (β = 0.26) were associated with an increased motor performance. For nonoverweight children results of the multiple linear regression analysis (R (2) = 0.09) found that a higher school grade (β = 0.17), sports club participation (β = 0.16),and more than 2 weekly lessons of physical education (β = 0.22) were associated with an increased motor performance. For the overweight children, results of the multiple linear regression analysis (R (2) = 0 .43) showed that no migration background (β = 0.23), a higher school grade (β = 0.55), sports club participation (β = 0.33) and more than 2 weekly lessons of physical

The Investigation of the Relationship between Children's 50m Freestyle Swimming Performances and Motor Performances

Science.gov (United States)

Aktug, Zait Burak; Iri, Ruckan; Top, Elif

2018-01-01

The aim of the study is to examine the relationship between children's 50 m freestyle swimming performances and motor performances. There were 32 swimmers (male = 21, female = 11), who had been swimming for at least one and a half year, participated in the study. The motor performances of the participating swimmers were determined through the…

Neurofeedback training of alpha-band coherence enhances motor performance.

Science.gov (United States)

Mottaz, Anais; Solcà, Marco; Magnin, Cécile; Corbet, Tiffany; Schnider, Armin; Guggisberg, Adrian G

2015-09-01

Neurofeedback training of motor cortex activations with brain-computer interface systems can enhance recovery in stroke patients. Here we propose a new approach which trains resting-state functional connectivity associated with motor performance instead of activations related to movements. Ten healthy subjects and one stroke patient trained alpha-band coherence between their hand motor area and the rest of the brain using neurofeedback with source functional connectivity analysis and visual feedback. Seven out of ten healthy subjects were able to increase alpha-band coherence between the hand motor cortex and the rest of the brain in a single session. The patient with chronic stroke learned to enhance alpha-band coherence of his affected primary motor cortex in 7 neurofeedback sessions applied over one month. Coherence increased specifically in the targeted motor cortex and in alpha frequencies. This increase was associated with clinically meaningful and lasting improvement of motor function after stroke. These results provide proof of concept that neurofeedback training of alpha-band coherence is feasible and behaviorally useful. The study presents evidence for a role of alpha-band coherence in motor learning and may lead to new strategies for rehabilitation. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Motor Performance as Risk Factor for Lower Extremity Injuries in Children

DEFF Research Database (Denmark)

Runge, Lisbeth; Kristensen, Peter Lund; Junge, Tina

2016-01-01

PURPOSE: Physical activity related injuries in children constitute a costly public health matter. The influence of motor performance on injury risk is unclear. The purpose was to examine if motor performance was a risk factor of traumatic and overuse lower extremity injuries in a normal population...... motor performance (core stability, vertical jump, shuttle run) was positively associated with traumatic and overuse injuries, and negatively (single leg hop) associated with traumatic injuries, indicating different influence on injury risk. Previous injury was a confounder affecting the effect size...... and the significance. More studies are needed to consolidate the findings, to clarify the influence of different performance tests on different types of injuries and to examine the influence of behaviour in relation to injury risk....

Simulation and Analysis of Magnetisation Characteristics of Interior Permanent Magnet Motors

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J. A. Walker

2005-01-01

Full Text Available Modern permanent magnet (PM synchronous brushless machines often have magnetic circuits in which the patterns of saturation are complex and highly variable with the position of the rotor. The classical phasor diagram theory of operation relies on the assumption of sinusoidal variation of flux-linkage with rotor position, and neglects the non-linear effects that arise in different operating states. The finite element method is a useful tool for detailed magnetic analysis, but it is important to verify simulation results by direct measurement of the magnetic characteristics of the motor, in terms of “magnetisation curves” of current and flux-linkage. This paper presents results from finite element simulations to determine the magnetisation in a split-phase interior permanent magnet (IPM motor. Investigation has been made to determine the effects of the rotor geometry on the synchronous reactances and airgap flux distribution. Comparisons are made with a second IPM motor with a different rotor configuration. 

Performance Analysis of Permanent Magnet Motors for Electric Vehicles (EV Traction Considering Driving Cycles

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Thanh Anh Huynh

2018-05-01

Full Text Available This paper evaluates the electromagnetic and thermal performance of several traction motors for electric vehicles (EVs. Two different driving cycles are employed for the evaluation of the motors, one for urban and the other for highway driving. The electromagnetic performance to be assessed includes maximum motor torque output for vehicle acceleration and the flux weakening capability for wide operating range under current and voltage limits. Thermal analysis is performed to evaluate the health status of the magnets and windings for the prescribed driving cycles. Two types of traction motors are investigated: two interior permanent magnet motors and one permanent magnet-assisted synchronous reluctance motor. The analysis results demonstrate the benefits and disadvantages of these motors for EV traction and provide suggestions for traction motor design. Finally, experiments are conducted to validate the analysis.

Stepper Motor Characterization Utilizing Borland Delphi 5.0

International Nuclear Information System (INIS)

Yoyok-Dwi-Setyo-Pambudi, Darlis

2005-01-01

Characterization of 12-Watt, Shinano Kensi, Japan. Stepper Motors series TEAC P.No.14769070.90 had been conducted. Knowledge obtained from this characteristic test can be exploited in motor stepper application in the field of robotics, the appliance of las automatization and also the metal clippers equipment. Test characteristic was performed by using computer program Borland Delphi version 5.0. The result showed that by using input delay time 10 ms, the quickest turn around frequency of the motor is 0.5 Hz. The longer delay time tend to make a rotation frequency became lower, it also mean the moving of motor became slower. (author)

Motor planning flexibly optimizes performance under uncertainty about task goals.

Science.gov (United States)

Wong, Aaron L; Haith, Adrian M

2017-03-03

In an environment full of potential goals, how does the brain determine which movement to execute? Existing theories posit that the motor system prepares for all potential goals by generating several motor plans in parallel. One major line of evidence for such theories is that presenting two competing goals often results in a movement intermediate between them. These intermediate movements are thought to reflect an unintentional averaging of the competing plans. However, normative theories suggest instead that intermediate movements might actually be deliberate, generated because they improve task performance over a random guessing strategy. To test this hypothesis, we vary the benefit of making an intermediate movement by changing movement speed. We find that participants generate intermediate movements only at (slower) speeds where they measurably improve performance. Our findings support the normative view that the motor system selects only a single, flexible motor plan, optimized for uncertain goals.

Traveling-wave piezoelectric linear motor part II: experiment and performance evaluation.

Science.gov (United States)

Ting, Yung; Li, Chun-Chung; Chen, Liang-Chiang; Yang, Chieh-Min

2007-04-01

This article continues the discussion of a traveling-wave piezoelectric linear motor. Part I of this article dealt with the design and analysis of the stator of a traveling-wave piezoelectric linear motor. In this part, the discussion focuses on the structure and modeling of the contact layer and the carriage. In addition, the performance analysis and evaluation of the linear motor also are dealt with in this study. The traveling wave is created by stator, which is constructed by a series of bimorph actuators arranged in a line and connected to form a meander-line structure. Analytical and experimental results of the performance are presented and shown to be almost in agreement. Power losses due to friction and transmission are studied and found to be significant. Compared with other types of linear motors, the motor in this study is capable of supporting heavier loads and provides a larger thrust force.

Application of stepping motor

International Nuclear Information System (INIS)

1980-10-01

This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

A Universal Motor Performance Test System Based on Virtual Instrument

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Wei Li

2014-09-01

Full Text Available With the development of technology universal motors play a more and more important role in daily life and production, they have been used in increasingly wide field and the requirements increase gradually. How to control the speed and monitor the real-time temperature of motors are key issues. The cost of motor testing system based on traditional technology platform is very high in many reasons. In the paper a universal motor performance test system which based on virtual instrument is provided. The system achieves the precise control of the current motor speed and completes the measurement of real-time temperature of motor bearing support in order to realize the testing of general-purpose motor property. Experimental result shows that the system can work stability in controlling the speed and monitoring the real-time temperature. It has advantages that traditional using of SCM cannot match in speed, stability, cost and accuracy aspects. Besides it is easy to expand and reconfigure.

Impact of extrinsic factors on fine motor performance of children attending day care

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Carolina Corsi

Full Text Available Abstract Objective: To assess the impact of extrinsic factors on fine motor performance of children aged 2-years old. Methods: 73 children attending public and 21 private day care centers were assessed. Day care environment was evaluated using the Infant/Toddler Environment Rating Scale-Revised Edition (ITERS-R, fine motor performance was assessed through the Bayley Scales of Infant and Toddler Development-III (BSITD-III, socioeconomic data, maternal education and time of start at the day care were collected through interviews. Spearman's correlation coefficient was calculated to assess the association between the studied variables. Results: The time at the day care was positively correlated with the children's performance in some fine motor tasks of the BSITD-III, showing that the activities developed in day care centers were important for the refinement of specific motor skills, while the overall fine motor performance by the scale was associated with maternal education and the ITERS-R scale sub-item “language and understanding”. Conclusions: Extrinsic factors such as higher maternal education and quality of day care centers are associated with fine motor performance in children attending day care.

Impact of extrinsic factors on fine motor performance of children attending day care.

Science.gov (United States)

Corsi, Carolina; Santos, Mariana Martins Dos; Marques, Luísa de Andrade Perez; Rocha, Nelci Adriana Cicuto Ferreira

2016-12-01

To assess the impact of extrinsic factors on fine motor performance of children aged two years old. 73 children attending public and 21 private day care centers were assessed. Day care environment was evaluated using the Infant/Toddler Environment Rating Scale - Revised Edition (ITERS-R), fine motor performance was assessed through the Bayley Scales of Infant and Toddler Development - III (BSITD-III), socioeconomic data, maternal education and time of start at the day care were collected through interviews. Spearman's correlation coefficient was calculated to assess the association between the studied variables. The time at the day care was positively correlated with the children's performance in some fine motor tasks of the BSITD-III, showing that the activities developed in day care centers were important for the refinement of specific motor skills, while the overall fine motor performance by the scale was associated with maternal education and the ITERS-R scale sub-item "language and understanding". Extrinsic factors such as higher maternal education and quality of day care centers are associated with fine motor performance in children attending day care. Copyright © 2016 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

Long-term performance of motor-operated valves

Energy Technology Data Exchange (ETDEWEB)

Scarbrough, T.G.

1996-12-01

The U.S. Nuclear Regulatory Commission (NRC) requires that motor-operated valves (MOVs) important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Despite these requirements, operating experience and research revealed problems with the performance of MOVs in operating nuclear power plants. In response to the concerns about MOV performance, the NRC issued Generic Letter (GL) 89-10, {open_quotes}Safety-Related Motor-Operated Valve Testing and Surveillance,{close_quotes} and its supplements. Most licensees have completed the aspects of their GL 89-10 programs associated with the review of MOV design bases, verification of MOV switch settings initially, testing of MOVs under design-basis conditions where practicable, and improvement of evaluations of MOV failures and necessary corrective action. Licensees are establishing processes to ensure that the long-term aspects of their MOV programs, such as periodic verification of MOV capability and the trending of MOV problems, are maintained. The NRC staff is developing a generic letter to address periodic verification of MOV design-basis capability.

Long-term performance of motor-operated valves

International Nuclear Information System (INIS)

Scarbrough, T.G.

1996-01-01

The U.S. Nuclear Regulatory Commission (NRC) requires that motor-operated valves (MOVs) important to safety be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed. Despite these requirements, operating experience and research revealed problems with the performance of MOVs in operating nuclear power plants. In response to the concerns about MOV performance, the NRC issued Generic Letter (GL) 89-10, open-quotes Safety-Related Motor-Operated Valve Testing and Surveillance,close quotes and its supplements. Most licensees have completed the aspects of their GL 89-10 programs associated with the review of MOV design bases, verification of MOV switch settings initially, testing of MOVs under design-basis conditions where practicable, and improvement of evaluations of MOV failures and necessary corrective action. Licensees are establishing processes to ensure that the long-term aspects of their MOV programs, such as periodic verification of MOV capability and the trending of MOV problems, are maintained. The NRC staff is developing a generic letter to address periodic verification of MOV design-basis capability

Hybrid Modelling of a Traveling Wave Piezoelectric Motor

DEFF Research Database (Denmark)

El, Ghouti N.

a theoretical model is derived. Since the dynamic characteristics of the real motor are difficult to capture in an analytical model, and the parameters of the motor are time varying and highly nonlinear, then some assumptions are required in order to simplify the modeling task and thus provide a suitable model......This thesis considers the modeling of the traveling wave piezoelectric motor (PEM). The rotary traveling wave ultrasonic motor "Shinsei type USR60" is the case study considered in this work. The traveling wave PEM has excellent performance and many useful features such as high holding torque, high....... Despite many attempts a lumped motor model of the PEM is unavailable so far. The dynamical characteristics of the PEM are complicated, highly nonlinear, and the motor parameters are time varying due to temperature rise and changes in motor drive operating conditions. Therefore it is difficult to predict...

Torque Characteristic Analysis of a Transverse Flux Motor Using a Combined-Type Stator Core

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Xiaobao Yang

2016-11-01

Full Text Available An external rotor transverse flux motor using a combined-type stator core is proposed for a direct drive application in this paper. The stator core is combined by two kinds of components that can both be manufactured conveniently by generic laminated silicon steel used in traditional motors. The motor benefits from the predominance of low manufacturing cost and low iron loss by using a silicon-steel sheet. Firstly, the basic structure and operation principles of the proposed motor are introduced. Secondly, the expressions of the electromagnetic torque and the cogging torque are deduced by theoretical analysis. Thirdly, the basic characteristics such as permanent magnet flux linkage, no-load back electromotive force, cogging torque and electromagnetic torque are analyzed by a three-dimensional finite element method (3D FEM. Then, the influence of structure parameters on the torque density is investigated, which provides a useful foundation for optimum design of the novel motor. Finally, the torque density of the proposed motor is calculated and discussed, and the result shows that the proposed motor in this paper can provide considerable torque density by using few permanent magnets.

Analysis of mechanical characteristics of superconducting field coil for 17 MW class high temperature superconducting synchronous motor

International Nuclear Information System (INIS)

Kim, J. H.; Park, S. I.; Im, S. H.; Kim, H. M.

2013-01-01

Superconducting field coils using a high-temperature superconducting (HTS) wires with high current density generate high magnetic field of 2 to 5 [T] and electromagnetic force (Lorentz force) acting on the superconducting field coils also become a very strong from the point of view of a mechanical characteristics. Because mechanical stress caused by these powerful electromagnetic force is one of the factors which worsens the critical current performance and structural characteristics of HTS wire, the mechanical stress analysis should be performed when designing the superconducting field coils. In this paper, as part of structural design of superconducting field coils for 17 MW class superconducting ship propulsion motor, mechanical stress acting on the superconducting field coils was analyzed and structural safety was also determined by the coupling analysis system that is consists of commercial electromagnetic field analysis program and structural analysis program.

Association between vestibular function and motor performance in hearing-impaired children.

Science.gov (United States)

Maes, Leen; De Kegel, Alexandra; Van Waelvelde, Hilde; Dhooge, Ingeborg

2014-12-01

The clinical balance performance of normal-hearing (NH) children was compared with the balance performance of hearing-impaired (HI) children with and without vestibular dysfunction to identify an association between vestibular function and motor performance. Prospective study. Tertiary referral center. Thirty-six children (mean age, 7 yr 5 mo; range, 3 yr 8 mo-12 yr 11 mo) divided into three groups: NH children with normal vestibular responses, HI children with normal vestibular responses, and HI children with abnormal vestibular function. A vestibular test protocol (rotatory and collic vestibular evoked myogenic potential testing) in combination with three clinical balance tests (balance beam walking, one-leg hopping, one-leg stance). Clinical balance performance. HI children with abnormal vestibular test results obtained the lowest quotients of motor performance, which were significantly lower compared with the NH group (p beam walking and one-leg stance; p = 0.003 for one-leg hopping). The balance performance of the HI group with normal vestibular responses was better in comparison with the vestibular impaired group but still significantly lower compared with the NH group (p = 0.020 for balance beam walking; p = 0.001 for one-leg stance; not significant for one-leg hopping). These results indicate an association between vestibular function and motor performance in HI children, with a more distinct motor deterioration if a vestibular impairment is superimposed to the auditory dysfunction.

Motor performance of preschool children

OpenAIRE

Słonka Karina; Dyas Manuela; Słonka Tadeusz; Szurmik Tomasz

2017-01-01

Słonka Karina, Dyas Manuela, Słonka Tadeusz, Szurmik Tomasz. Motor performance of preschool children. Journal of Education, Health and Sport. 2017;7(8):1308-1323. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.1045272 http://ojs.ukw.edu.pl/index.php/johs/article/view/5028 https://pbn.nauka.gov.pl/sedno-webapp/works/836989 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26.01.2017...

Motor unit activity when young and old adults perform steady contractions while supporting an inertial load

Science.gov (United States)

Gould, Jeffrey R.; Enoka, Roger M.

2013-01-01

The purpose of the study was to compare the discharge characteristics of biceps brachii motor units of young and old adults when they performed steady, submaximal contractions while the arm supported different inertial loads. Young (28 ± 4 yr; n = 16) and old (75 ± 4 yr; n = 14) adults performed steady contractions with the elbow flexors at target forces set at either small (11.7 ± 4.4% maximum) or large (17.8 ± 6.5% maximum) differences below the recruitment threshold force of the motor unit (n = 40). The task was to maintain an elbow angle at 1.57 rad until the motor unit was recruited and discharged action potentials for ∼120 s. Time to recruitment was longer for the larger target force difference (187 ± 227 s vs. 23 ± 46 s, P recruited, motor units discharged action potentials either repetitively or intermittently, with a greater proportion of motor units exhibiting the repetitive pattern for old adults. Discharge rate at recruitment and during the steady contraction was similar for the two target force differences for old adults but was greater for the small target force difference for young adults. Discharge variability was similar at recruitment for the two age groups but less for the old adults during the steady contraction. The greatest difference between the present results and those reported previously when the arm pulled against a rigid restraint was that old adults modulated discharge rate less than young adults across the two contraction intensities for both load types. PMID:23221403

THE RELATIONS OF MORPHOLOGIC CHARACTERISTICS AND MOTOR ABILITIES OF JOUNG WATER POLO PLAYERS

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Dragan Toskić

2013-07-01

Full Text Available The aim of our research was to determine the connection between morphologic characteristics and motor abilities of young water polo players. The sample of participants for this research can be defined as the population of water polo swimmers (N=60 aged 16 to 18, who were only included in the study under the condition that they have taken part in the water polo training process for a period of at least four years. In order to evaluate morphological characteristics of the participants we used 20 anthro¬po¬me¬tric variables (IBP to evaluated longitudinal and transversal dimenions, mass and body voluminosity and subcutaneous fatty tissue. In this study, the measurings of the sig¬ni¬ficant motor dimensions were carried by means of the following measuring instruments which the authors (Gredelj, Hošek, Metikoš, Momirović, 1975 had previously evaluated with the help of physiological mechanisms: the integration factor, based on the me¬cha¬nism for movement structure (MSK, the synergistic automatism and tonus regulation factor (SRT; the factor for excitation intensity regulation (RIE; the excitation duration re¬gulation factor (RTE. The relations between morphological and motor dimensions we¬re determined using a canonical correlation analysis. A correlation analysis was carried out and it indicated a very high correlation between dimesions morphological cha¬ra¬cte¬ri¬stics and motor abilities of young water polo players.

Segmented motor drive - with multi-phase induction motor

DEFF Research Database (Denmark)

Bendixen, Flemming Buus

of the induction motor is set up. The model is able to calculate dynamical electric, magnetic and mechanic state variables, but initially it is used to calculate static characteristics in motors with different number of phases and different voltage supply shapes. This analysis show i.e. that the efficiency....... The multi-phase motor is selected for further analysis. The project is limited to examine if increasing the number of phases can improve the characteristics for induction motor drives. In the literature it is demonstrated that torque production in a six-phase motor can be increased, if a 3rd harmonic......This PhD project commences in modulation of motor drives, i.e. having the advantage of reducing the number of variants and improves the system reliability at error situations. Four different motor drive topologies with modular construction as common denominator are compared on a general level...

Effectiveness of autogenic training in improving motor performances in Parkinson's disease.

Science.gov (United States)

Ajimsha, M S; Majeed, Nisar A; Chinnavan, Elanchezhian; Thulasyammal, Ramiah Pillai

2014-06-01

Relaxation training can be an important adjunct in reducing symptoms associated with Parkinson's disease (PD). Autogenic Training (AT) is a simple, easily administered and inexpensive technique for retraining the mind and the body to be able to relax. AT uses visual imagery and body awareness to promote a state of deep relaxation. To investigate whether AT when used as an adjunct to Physiotherapy (PT) improves motor performances in PD in comparison with a control group receiving PT alone. Randomized, controlled, single blinded trial. Movement Disorder Clinic and Department of Physiotherapy, Sree Chithira Thirunal Institute of Medical Sciences and Technology in Trivandrum, Kerala, India. Patients with PD of grade 2 or 3 of Hoehn & Yahr (H&Y) scale (N = 66). AT group or control group. The techniques were administered by Physiotherapists trained in AT and consisted of 40 sessions per patient over 8 weeks. Motor score subscale of Unified Parkinson's Disease Rating Scale (UPDRS) was used to measure the motor performances. The primary outcome measure was the difference in Motor score subscale of UPDRS scores between Week 1 (pretest score), Week 8 (posttest score), and follow-up at Week 12 after randomization. The simple main effects analysis showed that the AT group performed better than the control group in weeks 8 and 12 (P < .005). Patients in the AT and control groups reported a 51.78% and 35.24% improvement, respectively, in their motor performances in Week 8 compared with that in Week 1, which persisted, in the follow-up (Week 12) as 30.82% in the AT group and 21.42% in the control group. This study provides evidence that AT when used as an adjunct to PT is more effective than PT alone in improving motor performances in PD patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

Teeth grinding, oral motor performance and maximal bite force in cerebral palsy children.

Science.gov (United States)

Botti Rodrigues Santos, Maria Teresa; Duarte Ferreira, Maria Cristina; de Oliveira Guaré, Renata; Guimarães, Antonio Sergio; Lira Ortega, Adriana

2015-01-01

Identify whether the degree of oral motor performance is related to the presence of teeth grinding and maximal bite force values in children with spastic cerebral palsy. Ninety-five spastic cerebral palsy children with and without teeth grinding, according to caregivers' reports, were submitted to a comprehensive oral motor performance evaluation during the feeding process using the Oral Motor Assessment Scale. Maximal bite force was measured using an electronic gnathodynamometer. The teeth grinding group (n = 42) was younger, used anticonvulsant drugs, and was more frequently classified within the subfunctional oral motor performance category. Teeth grinding subfunctional spastic cerebral palsy children presented lower values of maximal bite force. The functional groups showing the presence or absence of teeth grinding presented higher values of maximal bite force compared with the subfunctional groups. In spastic cerebral palsy children, teeth grinding is associated with the worse oral motor performance. © 2015 Special Care Dentistry Association and Wiley Periodicals, Inc.

Effect of Frequency and Spatial-Harmonics on Rotary and Linear Induction Motor Characteristics

Science.gov (United States)

1972-03-01

A computer analysis is made of the effect of current and MMF airgap harmonics on the output characteristics of rotary and linear induction motors. The current harmonics accompanying thyristor-control operation are evaluated by Fourier analyzing the p...

Investigation of Electromagnetic, Thermal and Mechanical Characteristics of a Five-Phase Dual-Rotor Permanent-Magnet Synchronous Motor

Directory of Open Access Journals (Sweden)

Jing Zhao

2015-09-01

Full Text Available This paper investigates of a kind of five-phase dual-rotor permanent-magnet synchronous motor (DRPMSM, which contains dual rotors and a single stator. This kind of motor has the potential advantages of high power density, high reliability and high efficiency, which make it more appropriate for using in electric vehicles (EVs. In order to evaluate the most suitable power level for this kind of structure, the electromagnetic, the thermal and the mechanical characteristics are investigated in this paper. The length to diameter ratio of motors is researched to obtain the highest power density and then the optimum ratio is obtained. Based on the optimum ratio, the thermal characteristics are researched under natural condition and forced-air cooling condition with different wind speeds. In addition, the mechanical characteristics are analyzed under no-load and different loads conditions, respectively. All of the results are analyzed by two-dimension (2-D and three-dimension (3-D finite element method (FEM simulation, which provide a good reference to select suitable power level for this kind of motor structure. Finally, a DRPMSM prototype is manufactured and tested. The experimental results effectively verify the FEM results.

Concurrent word generation and motor performance: further evidence for language-motor interaction.

Directory of Open Access Journals (Sweden)

Amy D Rodriguez

Full Text Available Embodied/modality-specific theories of semantic memory propose that sensorimotor representations play an important role in perception and action. A large body of evidence supports the notion that concepts involving human motor action (i.e., semantic-motor representations are processed in both language and motor regions of the brain. However, most studies have focused on perceptual tasks, leaving unanswered questions about language-motor interaction during production tasks. Thus, we investigated the effects of shared semantic-motor representations on concurrent language and motor production tasks in healthy young adults, manipulating the semantic task (motor-related vs. nonmotor-related words and the motor task (i.e., standing still and finger-tapping. In Experiment 1 (n = 20, we demonstrated that motor-related word generation was sufficient to affect postural control. In Experiment 2 (n = 40, we demonstrated that motor-related word generation was sufficient to facilitate word generation and finger tapping. We conclude that engaging semantic-motor representations can have a reciprocal influence on motor and language production. Our study provides additional support for functional language-motor interaction, as well as embodied/modality-specific theories.

Effect of magnetic properties of non-oriented electrical steel on torque characteristics of interior-permanent-magnet synchronous motor

Energy Technology Data Exchange (ETDEWEB)

Fujimura, Hiroshi [Corporate Research and Development Laboratories, Sumitomo Metal Industries, Ltd., 1-8 Fuso-cho, Amagasaki 660-0891 (Japan)], E-mail: fujimura-hrs@sumitomometals.co.jp; Nitomi, Hirokatsu; Yashiki, Hiroyoshi [Corporate Research and Development Laboratories, Sumitomo Metal Industries, Ltd., 1-8 Fuso-cho, Amagasaki 660-0891 (Japan)

2008-10-15

The torque characteristics of interior-permanent-magnet synchronous motor (IPMSM), in which core materials were our conventional non-oriented electrical steel 35SX250 and our developed steels 35SXH, 27SXH with high permeability, were measured by a pulse wave modulation (PWM) inverter control. The torque characteristics of the motor with developed steels were superior to that of conventional steel. The advantage of developed steels was remarkable in the high-toque region. Experimental torque separation using current phase control showed that reluctance torque was strongly affected by the magnetic properties of core materials. And we did magnetic field analysis of the motors by finite element method (FEM). The flux density in the teeth of the stator core was higher in the high permeability steels than that in the conventional steel under the same current condition. The developed steels are expected to be suited to the stator material of IPMSM used as drive motors for electric vehicles and compressor motors for air conditioner.

Effect of magnetic properties of non-oriented electrical steel on torque characteristics of interior-permanent-magnet synchronous motor

International Nuclear Information System (INIS)

Fujimura, Hiroshi; Nitomi, Hirokatsu; Yashiki, Hiroyoshi

2008-01-01

The torque characteristics of interior-permanent-magnet synchronous motor (IPMSM), in which core materials were our conventional non-oriented electrical steel 35SX250 and our developed steels 35SXH, 27SXH with high permeability, were measured by a pulse wave modulation (PWM) inverter control. The torque characteristics of the motor with developed steels were superior to that of conventional steel. The advantage of developed steels was remarkable in the high-toque region. Experimental torque separation using current phase control showed that reluctance torque was strongly affected by the magnetic properties of core materials. And we did magnetic field analysis of the motors by finite element method (FEM). The flux density in the teeth of the stator core was higher in the high permeability steels than that in the conventional steel under the same current condition. The developed steels are expected to be suited to the stator material of IPMSM used as drive motors for electric vehicles and compressor motors for air conditioner

Performance and touch characteristics of disabled and non-disabled participants during a reciprocal tapping task using touch screen technology.

Science.gov (United States)

Irwin, Curt B; Sesto, Mary E

2012-11-01

Touch screens are becoming more prevalent in everyday environments. Therefore, it is important that this technology is accessible to those with varying disabilities. The objective of the current study was to evaluate performance and touch characteristics (forces, impulses, and dwell times) of individuals with and without a movement disorder during a reciprocal tapping touch screen task. Thirty-seven participants with a motor control disability and 15 non-disabled participants participated. Outcome measures include number of correct taps, dwell time, exerted force, and impulse. Results indicate non-disabled participants had 1.8 more taps than participants with fine motor control disabilities and 2.8 times more than those with gross motor impairments (ptouch characteristics exist between those with and without motor control disabilities. Understanding how people (including those with disabilities) interact with touch screens may allow designers and engineers to ultimately improve usability of touch screen technology. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Cognitive Orientation to (daily) Occupational Performance (CO-OP) with children with Asperger's syndrome who have motor-based occupational performance goals.

Science.gov (United States)

Rodger, Sylvia; Brandenburg, Julia

2009-02-01

Motor difficulties associated with Asperger's syndrome (AS) are commonly reported, despite these not being diagnostically significant. Cognitive Orientation to daily Occupational Performance (CO-OP) is a verbal problem-solving intervention developed for use with children with developmental coordination disorder to address their motor-based difficulties. This paper reports on two case studies of children with AS illustrating the outcomes of CO-OP to address motor-based occupational performance goals. A case study approach was used to document how two children with AS engaged in 10 weekly sessions of CO-OP addressing child-chosen motor-based occupational performance goals and the outcomes of this intervention. Pre and post-intervention assessment using the Canadian Occupational Performance Measure, Vineland Adaptive Behaviour Scales and the Performance Quality Rating Scale indicated that both children were able to engage in CO-OP intervention to successfully improve their occupational performance. Further research into the application of CO-OP with children with AS is warranted based on preliminary positive findings regarding the efficacy of this intervention to address motor-based performance difficulties in two children with AS.

Discharge properties of motor units during steady isometric contractions performed with the dorsiflexor muscles.

Science.gov (United States)

Jesunathadas, Mark; Klass, Malgorzata; Duchateau, Jacques; Enoka, Roger M

2012-06-01

The purpose of this study was to record the discharge characteristics of tibialis anterior motor units over a range of target forces and to import these data, along with previously reported observations, into a computational model to compare experimental and simulated measures of torque variability during isometric contractions with the dorsiflexor muscles. The discharge characteristics of 44 motor units were quantified during brief isometric contractions at torques that ranged from recruitment threshold to an average of 22 ± 14.4% maximal voluntary contraction (MVC) torque above recruitment threshold. The minimal [range: 5.8-19.8 pulses per second (pps)] and peak (range: 8.6-37.5 pps) discharge rates of motor units were positively related to the recruitment threshold torque (R(2) ≥ 0.266; P recruitment was positively associated with recruitment threshold torque (R(2) = 0.443; P recruitment threshold torque. The variability in the simulated torque did not differ from the experimental values once the recruitment range was set to ∼85% MVC torque, and the association between motor twitch contraction times and peak twitch torque was defined as a weak linear association (R(2) = 0.096; P motor units in the tibialis anterior.

Motor performance is not enhanced by daytime naps in older adults

Directory of Open Access Journals (Sweden)

Winifried eBackhaus

2016-05-01

Full Text Available The impact of sleep on motor learning in the aging brain was investigated using an experimental diurnal nap setup. As the brain ages several components of learning as well as motor performance change. In addition, aging is also related to sleep architectural changes. This combination of slowed learning processes and impaired sleep behavior raises the question of whether sleep can enhance learning and specifically performance of procedural tasks in healthy, older adults. Previous research was able to show sleep-dependent consolidation overnight for numerous tasks in young adults. Some of these study findings can also be replicated for older adults. This study aims to clarify whether sleep-dependent consolidation can also be found during shorter periods of diurnal sleep. The impact of midday naps on motor consolidation was analyzed by comparing procedural learning using a sequence and a motor adaptation task, in a crossover fashion in healthy, non-sleep deprived, older adults randomly subjected to wake (45 min, short nap (10-20 min sleep or long nap (50-70 min sleep conditions. Older adults exhibited learning gains, these were not found to be sleep-dependent in either task. The results suggest that daytime naps do not have an impact on performance and motor learning in an aging population.

Teacher Compliance and Accuracy in State Assessment of Student Motor Skill Performance

Science.gov (United States)

Hall, Tina J.; Hicklin, Lori K.; French, Karen E.

2015-01-01

Purpose: The purpose of this study was to investigate teacher compliance with state mandated assessment protocols and teacher accuracy in assessing student motor skill performance. Method: Middle school teachers (N = 116) submitted eighth grade student motor skill performance data from 318 physical education classes to a trained monitoring…

High-performance permanent magnet brushless motors with balanced concentrated windings and similar slot and pole numbers

International Nuclear Information System (INIS)

Stumberger, Bojan; Stumberger, Gorazd; Hadziselimovic, Miralem; Hamler, Anton; Trlep, Mladen; Gorican, Viktor; Jesenik, Marko

2006-01-01

The paper presents a comparison between the performances of exterior-rotor permanent magnet brushless motors with distributed windings and the performances of exterior-rotor permanent magnet brushless motors with concentrated windings. Finite element method analysis is employed to determine the performance of each motor. It is shown that motors with concentrated windings and similar slot and pole numbers exhibit similar or better performances than motors with distributed windings for brushless AC (BLAC) operation mode and brushless DC (BLDC) operation mode as well

Air pollution from motor vehicle emissions

International Nuclear Information System (INIS)

Petrushevska, Ljubica

1996-01-01

This paper presents some aspects of air pollution from motor vehicle emissions as: characteristic primary and secondary pollutants, dependence of the motor vehicle emission from the engine type; the relationship of typical engine emission and performance to air-fuel ratio, transport of pollutants from mobile sources of emissions, as well as some world experiences in the control approaches for exhaust emissions. (author)

Effects of occupational therapy services on fine motor and functional performance in preschool children.

Science.gov (United States)

Case-Smith, J

2000-01-01

This study examined how performance components and variables in intervention influenced fine motor and functional outcomes in preschool children. In a sample of 44 preschool-aged children with fine motor delays who received occupational therapy services, eight fine motor and functional performance assessments were administered at the beginning and end of the academic year. Data on the format and intervention activities of each occupational therapy session were recorded for 8 months. The children received a mean of 23 sessions, in both individual and group format. Most of the sessions (81%) used fine motor activities; 29% addressed peer interaction, and 16% addressed play skills. Visual motor outcomes were influenced by the number of intervention sessions and percent of sessions with play goals. Fine motor outcomes were most influenced by the therapists' emphasis on play and peer interaction goals; functional outcomes were influenced by number of sessions and percent of sessions that specifically addressed self-care goals. The influence of play on therapy outcomes suggests that a focus on play in intervention activities can enhance fine motor and visual motor performance.

Relationship between children's performance-based motor skills and child, parent, and teacher perceptions of children's motor abilities using self/informant-report questionnaires.

Science.gov (United States)

Lalor, Aislinn; Brown, Ted; Murdolo, Yuki

2016-04-01

Occupational therapists often assess the motor skill performance of children referred to them as part of the assessment process. This study investigated whether children's, parents' and teachers' perceptions of children's motor skills using valid and reliable self/informant-report questionnaires were associated with and predictive of children's actual motor performance, as measured by a standardised performance-based motor skill assessment. Fifty-five typically developing children (8-12 years of age), their parents and classroom teachers were recruited to participate in the study. The children completed the Physical Self-Description Questionnaire (PSDQ) and the Self-Perception Profile for Children. The parents completed the Developmental Profile III (DP-III) and the Developmental Coordination Disorder Questionnaire, whereas the teachers completed the Developmental Coordination Disorder Questionnaire and the Teacher's Rating Scale of Child's Actual Behavior. Children's motor performance composite scores were determined using the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition (BOT-2). Spearman's rho correlation coefficients were calculated to identify if significant correlations existed and multiple linear regression was used to identify whether self/informant report data were significant predictors of children's motor skill performance. The child self-report scores had the largest number of significant correlations with the BOT-2 composites. Regression analysis found that the parent report DP-III Physical subscale was a significant predictor of the BOT-2 Manual Coordination composite and the child-report questionnaire PSDQ. Endurance subscale was a significant predictor of the BOT-2 Strength and Agility composite. The findings support the use of top-down assessment methods from a variety of sources when evaluating children's motor abilities. © 2016 Occupational Therapy Australia.

The Performance of Fundamental Gross Motor Skills by Children Enrolled in Head Start.

Science.gov (United States)

Woodard, Rebecca J.; Yun, Joonkoo

2001-01-01

This study sought to descriptively evaluate the performance of fundamental gross motor skills among Head Start children. Levels of performance were compared and contrasted with performance profiles of the Test of Gross Motor Development. Findings suggest that Head Start curriculum should focus on the importance of developing fundamental gross…

Melodic Priming of Motor Sequence Performance: The Role of the Dorsal Premotor Cortex

Directory of Open Access Journals (Sweden)

Marianne Anke Stephan

2016-05-01

Full Text Available The purpose of this study was to determine whether exposure to specific auditory sequences leads to the induction of new motor memories and to investigate the role of the dorsal premotor cortex (dPMC in this crossmodal learning process. Fifty-two young healthy non-musicians were familiarized with the sound to key-press mapping on a computer keyboard and tested on their baseline motor performance. Each participant received subsequently either continuous theta burst stimulation (cTBS or sham stimulation over the dPMC and was then asked to remember a 12-note melody without moving. For half of the participants, the contour of the melody memorized was congruent to a subsequently performed, but never practiced, finger movement sequence (Congruent group. For the other half, the melody memorized was incongruent to the subsequent finger movement sequence (Incongruent group. Hearing a congruent melody led to significantly faster performance of a motor sequence immediately thereafter compared to hearing an incongruent melody. In addition, cTBS speeded up motor performance in both groups, possibly by relieving motor consolidation from interference by the declarative melody memorization task. Our findings substantiate recent evidence that exposure to a movement-related tone sequence can induce specific, crossmodal encoding of a movement sequence representation. They further suggest that cTBS over the dPMC may enhance early offline procedural motor skill consolidation in cognitive states where motor consolidation would normally be disturbed by concurrent declarative memory processes. These findings may contribute to a better understanding of auditory-motor system interactions and have implications for the development of new motor rehabilitation approaches using sound and non-invasive brain stimulation as neuromodulatory tools.

Effects of Different Environment Temperatures on Some Motor Characteristics and Muscle Strength

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Çakir, Ergün; Yüksek, Selami; Asma, Bülent; Arslanoglu, Erkal

2016-01-01

The aim of this study was determine the effects of different environment temperatures on motor characteristics and muscle strength. 15 athletes participated to study. Flexibility, vertical jump, hand grip-leg strength, 30m sprint, 20-meter shuttle run and coordination-agility tests were measured in five different environment temperatures. (22°C,…

Quantitative Motor Performance and Sleep Benefit in Parkinson Disease.

Science.gov (United States)

van Gilst, Merel M; van Mierlo, Petra; Bloem, Bastiaan R; Overeem, Sebastiaan

2015-10-01

Many people with Parkinson disease experience "sleep benefit": temporarily improved mobility upon awakening. Here we used quantitative motor tasks to assess the influence of sleep on motor functioning in Parkinson disease. Eighteen Parkinson patients with and 20 without subjective sleep benefit and 20 healthy controls participated. Before and directly after a regular night sleep and an afternoon nap, subjects performed the timed pegboard dexterity task and quantified finger tapping task. Subjective ratings of motor functioning and mood/vigilange were included. Sleep was monitored using polysomnography. On both tasks, patients were overall slower than healthy controls (night: F2,55 = 16.938, P Parkinson patients. Here we show that the subjective experience of sleep benefit is not paralleled by an actual improvement in motor functioning. Sleep benefit therefore appears to be a subjective phenomenon and not a Parkinson-specific reduction in symptoms. © 2015 Associated Professional Sleep Societies, LLC.

Effects of Motor Skill Intervention on Gross Motor Development, Creative Thinking and Academic Performance in Preschool Children

Directory of Open Access Journals (Sweden)

Judith Jiménez Díaz

2010-08-01

Full Text Available The purpose of this study was to investigate how students (mean= 6.08±0.5 years benefit from a physical education program in motor performance, creative thinking and academic achievement. Students (n = 39 were randomly assigned to comparison group (6 boys and 7 girls who received the regular preschool program (which includes 1 session of 30 minutes per week; intervention group 1 (6 boys and 7 girls who received the regular preschool program plus 1 session of 30 minutes per week of the intervention program; or intervention group 2 (6 boys and 7 girls, who received the regular preschool program plus 1 session of 60 minutes per week of the intervention program; during 8 weeks. All participants performed the Test of Gross Motor Development (TGMD-2 and the Torrance Test of Creative Thinking (TTCT before and after the study. The academic achievement score was given by the school. The ANOVA (Group x Gender x Time pre and post analysis revealed a significant triple interaction in the object control. Significant double interactions in the locomotor subscale and in the gross motor quotient were also found. After the post-hoc analysis, the results suggest that the physical education program benefits the gross motor performance and did not have an effect on the creative thinking or on the academic achievement.

Effects of interactive games on motor performance in children with spastic cerebral palsy.

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AlSaif, Amer A; Alsenany, Samira

2015-06-01

[Purpose] Motor control and muscle strength impairments are the prime reasons for motor behavior disorders in children with spastic cerebral palsy. These impairments lead to histological changes in muscle growth and the learning of motor skills. Therefore, such children experience reduced muscle force generation and decreased muscle flexibility. We investigated the effect of training with Nintendo Wii Fit games on motor performance in children with spastic cerebral palsy. [Subjects and Methods] Forty children with cerebral palsy spastic diplegia aged 6-10 years diagnosed with level-3 functional capabilities according to the Gross Motor Classification System (GMFCS) were enrolled. Participants were divided randomly into equal groups: group (A) that practiced with the Nintendo Wii Fit game for at least 20 minutes/day for 12 weeks and group (B) that underwent no training (control group). The Movement Assessment Battery for Children-2 (mABC-2) was used to assess motor performance, because it mainly involves motor tasks very similar to those involved in playing Nintendo Wii Fit games, e.g., goal-directed arm movements, balancing, and jumping. [Results] There were significant improvements in the subscales of the motor performance test of those who practiced with the Nintendo Wii, while the control group showed no significant changes. [Conclusion] Using motion interactive games in home rehabilitation is feasible for children with cerebral palsy.

Two is better than one: Physical interactions improve motor performance in humans

Science.gov (United States)

Ganesh, G.; Takagi, A.; Osu, R.; Yoshioka, T.; Kawato, M.; Burdet, E.

2014-01-01

How do physical interactions with others change our own motor behavior? Utilizing a novel motor learning paradigm in which the hands of two - individuals are physically connected without their conscious awareness, we investigated how the interaction forces from a partner adapt the motor behavior in physically interacting humans. We observed the motor adaptations during physical interactions to be mutually beneficial such that both the worse and better of the interacting partners improve motor performance during and after interactive practice. We show that these benefits cannot be explained by multi-sensory integration by an individual, but require physical interaction with a reactive partner. Furthermore, the benefits are determined by both the interacting partner's performance and similarity of the partner's behavior to one's own. Our results demonstrate the fundamental neural processes underlying human physical interactions and suggest advantages of interactive paradigms for sport-training and physical rehabilitation.

Sensory threshold neuromuscular electrical stimulation fosters motor imagery performance.

Science.gov (United States)

Corbet, Tiffany; Iturrate, Iñaki; Pereira, Michael; Perdikis, Serafeim; Millán, José Del R

2018-04-21

Motor imagery (MI) has been largely studied as a way to enhance motor learning and to restore motor functions. Although it is agreed that users should emphasize kinesthetic imagery during MI, recordings of MI brain patterns are not sufficiently reliable for many subjects. It has been suggested that the usage of somatosensory feedback would be more suitable than standardly used visual feedback to enhance MI brain patterns. However, somatosensory feed-back should not interfere with the recorded MI brain pattern. In this study we propose a novel feedback modality to guide subjects during MI based on sensory threshold neuromuscular electrical stimulation (St-NMES). St-NMES depolarizes sensory and motor axons without eliciting any muscular contraction. We hypothesize that St-NMES does not induce detectable ERD brain patterns and fosters MI performance. Twelve novice subjects were included in a cross-over design study. We recorded their EEG, comparing St-NMES with visual feed-back during MI or resting tasks. We found that St-NMES not only induced significantly larger desynchronization over sensorimotor areas (p<0.05) but also significantly enhanced MI brain connectivity patterns. Moreover, classification accuracy and stability were significantly higher with St-NMES. Importantly, St-NMES alone did not induce detectable artifacts, but rather the changes in the detected patterns were due to an increased MI performance. Our findings indicate that St-NMES is a promising feedback in order to foster MI performance and cold be used for BMI online applications. Copyright © 2018. Published by Elsevier Inc.

Proposed torque optimized behavior for digital speed control of induction motors

Energy Technology Data Exchange (ETDEWEB)

Metwally, H.M.B.; El-Shewy, H.M.; El-Kholy, M.M. [Zagazig Univ., Dept. of Electrical Engineering, Zagazig (Egypt); Abdel-Kader, F.E. [Menoufyia Univ., Dept. of Electrical Engineering, Menoufyia (Egypt)

2002-09-01

In this paper, a control strategy for speed control of induction motors with field orientation is proposed. The proposed method adjusts the output voltage and frequency of the converter to operate the motor at the desired speed with maximum torque per ampere at all load torques keeping the torque angle equal to 90 deg. A comparison between the performance characteristics of a 2 hp induction motor using three methods of speed control is presented. These methods are the proposed method, the direct torque control method and the constant V/f method. The comparison showed that better performance characteristics are obtained using the proposed speed control strategy. A computer program, based on this method, is developed. Starting from the motor parameters, the program calculates a data set for the stator voltage and frequency required to obtain maximum torque per ampere at any motor speed and load torque. This data set can be used by the digital speed control system of induction motors. (Author)

Driving performance of a two-dimensional homopolar linear DC motor

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.; Yamaguchi, M.; Kano, Y. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

1998-05-01

This paper presents a novel two-dimensional homopolar linear de motor (LDM) which can realize two-dimensional (2-D) motion. For position control purposes, two kinds of position detecting methods are proposed. The position in one position is detected by means of a capacitive sensor which makes the output of the sensor partially immune to the variation of the gap between electrodes. The position in the other direction is achieved by exploiting the position dependent property of the driving coil inductance, instead of using an independent sensor. The position control is implemented on the motor and 2-D tracking performance is analyzed. Experiments show that the motor demonstrates satisfactory driving performance, 2-D tracking error being within 5.5% when the angular frequency of reference signal is 3.14 rad./s. 7 refs., 17 figs., 2 tabs.

Performance exploration of an energy harvester near the varying magnetic field of an operating induction motor

International Nuclear Information System (INIS)

Uzun, Yunus; Kurt, Erol

2013-01-01

Highlights: • This paper explores the piezoelectric harvester performance. • The varying magnetic field generates electricity via exciting harvester. • Generated power should be optimized via load resistance. • 0.11 mW/cm 3 Power can be generated from 500 cm 3 surrounding volume. - Abstract: This paper reports a performance exploration of a piezoelectric harvester which is positioned near an operating induction motor. The harvester includes a magnet knob in a pendulum arrangement, which ascertains mechanical vibrations under the varying magnetic field. This energy harvester transforms the ambient unused magnetic energy into the electricity due to the piezoelectric layer attached to the pendulum. It has been proven that when the motor is under operation, the varying ambient field causes a varying magnetic force at the tip of harvester, then output voltage between the terminals of piezoelectric layer is produced due to the mechanical vibrations. This output signal has some characteristics of the operating induction motor in terms of its operation frequency, number of magnetic pole and natural frequency of the harvester. Since the surrounding field of the induction motor directly depends on the current flowing through the windings and electrical parameters, both the amplitude U and the frequency ω m of the harvested voltage can be characterized after some certain parametrical explorations. It has been proven that the harvested voltage strictly depends on the electrical load, which is attached to the terminals of the harvester, after the rectifying circuit. The harvested power per surrounding volume can be increased up to 0.11 mW/cm 3 , if the entire surrounding volume of the motor is considered

Roentgenological characteristics of motor-evacuatory stomach function after selective proximal vagotomy (SPV)

International Nuclear Information System (INIS)

Rustamov, Eh.A.; Manafov, S.S.

1988-01-01

An x-ray picture of motor-evacuatory stomach function was studied in patients with pyloroduodenal ulcers after SPV with and without drainage (435 patients aged 16 to 80). Methods of investigation included polyprojectional radioscopy and panoramic and spot films at various time intervals after barium suspension intake. Stomach investigation was performed before operation as well as 2-3 weeks, 3-6 mos, 1-2 yrs, 3-5 yrs, and 7-10 yrs after it. Motor-evacuatory stomach function was studied over time. The least changes in motor-evacuatory fucntion were observed after SPV without drainage as a result of preserving pyloric contractility

Motor-enriched learning activities can improve mathematical performance in preadolescent children

DEFF Research Database (Denmark)

Beck, Mikkel Malling; Lind, Rune Rasmussen; Geertsen, Svend Sparre

2016-01-01

Objective: An emerging field of research indicates that physical activity can benefit cognitive functions and academic achievements in children. However, less is known about how academic achievements can benefit from specific types of motor activities (e.g., fine and gross) integrated into learning......-enriched mathematical teaching in Danish preadolescent children (n = 165, age = 7.5 ± 0.02 years). Three groups were included: a control group (CON), which received non-motor enriched conventional mathematical teaching, a fine motor math group (FMM) and a gross motor math group (GMM), which received mathematical.......73 correct answers (p = 0.04) and FMM 2.14 ± 0.72 correct answers (p = 0.008). These effects were not observed in low math-performers. The effects were partly accounted for by visuo-spatial short-term memory and gross motor skills. Conclusion: The study demonstrates that motor enriched learning activities...

Integral performance optimum design for multistage solid propellant rocket motors

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hongtao (Shaanxi Power Machinery Institute (China))

1989-04-01

A mathematical model for integral performance optimization of multistage solid propellant rocket motors is presented. A calculation on a three-stage, volume-fixed, solid propellant rocket motor is used as an example. It is shown that the velocity at burnout of intermediate-range or long-range ballistic missile calculated using this model is four percent greater than that using the usual empirical method.

MOV motor and gearbox performance under design basis loads

International Nuclear Information System (INIS)

DeWall, K.G.; Watkins, J.C.

1998-01-01

This paper describes the results of valve testing sponsored by the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research and conducted at the Idaho National Engineering and Environmental Laboratory. The research objective was to evaluate the capabilities of specific actuator motor and gearbox assemblies under various design basis loading conditions. The testing was performed using the motor-operated valve load simulator, a test fixture that simulates the stem load profiles a valve actuator would experience when closing a valve against flow and pressure loadings. The authors tested five typical motors (four ac motors and one dc motor) with three gearbox assemblies at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. The authors also determined the efficiency of the actuator gearbox. The testing produced the following significant results: all five motors operated at or above their rated torque during tests at full voltage and ambient temperature; for all five motors (dc as well as ac), the actual torque loss due to voltage degradation was greater than the torque loss predicted using common methods; startup torques in locked rotor tests compared well with stall torques in dynamometer-type tests; the methods commonly used to predict torque losses due to elevated operating temperatures sometimes bounded the actual losses, but not in all cases; the greatest discrepancy involved the prediction for the dc motor; running efficiencies published by the manufacturer for actuator gearboxes were higher than the actual efficiencies determined from testing, in some instances, the published pullout efficiencies were also higher than the actual values; operation of the gearbox at elevated temperature did not affect the operating efficiency

Levitation Performance of Two Opposed Permanent Magnet Pole-Pair Separated Conical Bearingless Motors

Science.gov (United States)

Kascak, Peter; Jansen, Ralph; Dever, Timothy; Nagorny, Aleksandr; Loparo, Kenneth

2013-01-01

In standard motor applications, rotor suspension with traditional mechanical bearings represents the most economical solution. However, in certain high performance applications, rotor suspension without contacting bearings is either required or highly beneficial. Examples include applications requiring very high speed or extreme environment operation, or with limited access for maintenance. This paper expands upon a novel bearingless motor concept, in which two motors with opposing conical air-gaps are used to achieve full five-axis levitation and rotation of the rotor. Force in this motor is created by deliberately leaving the motor s pole-pairs unconnected, which allows the creation of different d-axis flux in each pole pair. This flux imbalance is used to create lateral force. This approach is different than previous bearingless motor designs, which require separate windings for levitation and rotation. This paper examines the predicted and achieved suspension performance of a fully levitated prototype bearingless system.

Electrodynamic ratchet motor.

Science.gov (United States)

Lim, Jiufu; Sader, John E; Mulvaney, Paul

2009-03-01

Brownian ratchets produce directed motion through rectification of thermal fluctuations and have been used for separation processes and colloidal transport. We propose a flashing ratchet motor that enables the transduction of electrical energy into rotary micromechanical work. This is achieved through torque generation provided by boundary shaping of equipotential surfaces. The present device contrasts to previous implementations that focus on translational motion. Stochastic simulations elucidate the performance characteristics of this device as a function of its geometry. Miniaturization to nanoscale dimensions yields rotational speeds in excess of 1 kHz, which is comparable to biomolecular motors of similar size.

Numerical and experimental comparison of electromechanical properties and efficiency of HTS and ferromagnetic hysteresis motors

International Nuclear Information System (INIS)

Inacio, D; Inacio, S; Pina, J; Goncalves, A; Neves, M Ventim; Rodrigues, A Leao

2008-01-01

Hysteresis motors are very attractive in a wide range of fractional power applications, due to its torque-speed characteristics and simplicity of construction. This motor's performance is expected to improve when HTS rotors are used, and in fact, hysteresis motors have shown to be probably the most viable electrical machines using HTS materials. While these motors, either conventional or HTS, are both hysteresis motors, they base their operation on different physical phenomena: hysteretic behaviour in conventional ferromagnetic materials is due to the material's non-linear magnetic properties, while in HTS materials the hysteresis has an ohmic nature and is related with vortices' dynamics. In this paper, theoretical aspects of both conventional and HTS hysteresis motors are discussed, its operation principles are highlighted, and the characteristics of both motors are presented. The characteristics, obtained both by experimental tests and numerical simulation (made with commercial software), are compared, in order to evaluate not only the motor's electromechanical performances but also the overall systems efficiency, including cryogenics for the HTS device

A flight simulator control system using electric torque motors

Science.gov (United States)

Musick, R. O.; Wagner, C. A.

1975-01-01

Control systems are required in flight simulators to provide representative stick and rudder pedal characteristics. A system has been developed that uses electric dc torque motors instead of the more common hydraulic actuators. The torque motor system overcomes certain disadvantages of hydraulic systems, such as high cost, high power consumption, noise, oil leaks, and safety problems. A description of the torque motor system is presented, including both electrical and mechanical design as well as performance characteristics. The system develops forces sufficiently high for most simulations, and is physically small and light enough to be used in most motion-base cockpits.

Electromagnetic characteristics and static torque of a solid salient poles synchronous motor computed by 3D-finite element method magnetics

International Nuclear Information System (INIS)

Popnikolova Radevska, Mirka; Cundev, Milan; Petkovska, Lidija

2002-01-01

In these paper is presented a methodology for numerical determination and complex analysis of the electromagnetic characteristics of the Solid Salient Poles Synchronous Motor, with rated data: 2.5 kW, 240 V and 1500 r.p.m.. A mathematical model and original algorithm for the nonlinear and iterative calculations by using Finite Element Method in 3D domain will be given. The program package FEM-3D will be used to perform automatically mesh generation of the finite elements in the 3D domain, calculation of the magnetic field distribution, as well as electromagnetic characteristics and Static torque in SSPSM. (Author)

Spatially defined disruption of motor imagery performance in people with osteoarthritis

NARCIS (Netherlands)

Stanton, T.R.; Lin, C.W.; Smeets, R.J.P.; Taylor, D.; Law, R.; Lorimer Moseley, G.

2012-01-01

OBJECTIVES: To determine whether motor imagery performance is disrupted in patients with painful knee OA and if this disruption is specific to the location of the pain. METHODS: Twenty patients with painful knee OA, 20 patients with arm pain and 20 healthy pain-free controls undertook a motor

Single phase induction motor with starting performance

Energy Technology Data Exchange (ETDEWEB)

Popescu, M.; Demeter, E. [Research Institute for Electrical Machines, ICPE-ME, Bucharest (Romania); Navrapescu, V. [University `Politehnica` Bucharest, Electrical Engineering Faculty Splaiul Independentei, Bucharest (Romania)

1997-12-31

The paper presents problems related to a special type of single phase induction motor. The main novelty consists in the use of a conducting (aluminium casted) shell distributed on the periferic region of the rotor. As a result the starting performance, as well as the rated ones, is much improved in comparison with the conventional construction. (orig.) 4 refs.

Diagnóstico diferencial dos distúrbios motores esofagianos pelas características da disfagia Differential diagnosis of esophageal motor disorders based in characteristics of dysphagia

Directory of Open Access Journals (Sweden)

Gerson R. DOMINGUES

2001-01-01

disorders and its caracterization is important for diagnosis and management of patients. Anamnesis is useful for differenciating organic and functional dysphagia, but data are lacking about dysphagia characterization among different motor disorders. Objectives - To evaluate if it is possible the distinction among esophageal motor disorders according to their manometric diagnosis, based on dysphagia characteristics. Patients and Methods - Dysphagia characteristics (relation with bolus, frequency and localization of 133 patients submitted to esophageal manometry were reviewed and analysed. All patients had barium swallow studies and/or endoscopy in order to exclude organic lesions. Results - Esophageal manometry was abnormal in 85% of the patients. Characteristics of dysphagia were compared among groups of patients with achalasia, esophageal spastic disorders, non-specific esophageal motor disorders and with normal test. The precise distinction among groups based solely on characteristics of dysphagia was not possible, however some aspects could point to one or another group. In achalasia patients, dysphagia for both solid food and liquids, constant and felt in substernal area, was more frequent in relation to every other group. Intermitent dysphagia was more frequent in patients with spastic disorders. Characteristics of dysphagia in patients with non-specific esophageal motor disorders were similar to those observed in the group with normal test, frequently referred in the neck. Conclusion - Characteristics of dysphagia were ancillary to presume the diagnosis of these motor disturbances, however esophageal manometry is necessary for the correct diagnosis in patients with functional dysphagia.

Altered neuronal activities in the motor cortex with impaired motor performance in adult rats observed after infusion of cerebrospinal fluid from amyotrophic lateral sclerosis patients.

Science.gov (United States)

Sankaranarayani, R; Nalini, A; Rao Laxmi, T; Raju, T R

2010-01-05

Although definite evidences are available to state that, neuronal activity is a prime determinant of animal behavior, the specific relationship between local field potentials of the motor cortex after intervention with CSF from human patients and animal behavior have remained opaque. The present study has investigated whether cerebrospinal fluid from sporadic amyotrophic lateral sclerosis (sALS) patients could disrupt neuronal activity of the motor cortex, which could be associated with disturbances in the motor performance of adult rats. CSF from ALS patients (ALS-CSF) was infused into the lateral ventricle of Wistar rats. After 24h, the impact of ALS-CSF on the local field potentials (LFPs) of the motor cortex and on the motor behavior of animals were examined. The results indicate that ALS-CSF produced a bivariate distribution on the relative power values of the LFPs of the motor cortex 24h following infusion. However, the behavioral results did not show bimodality, instead showed consistent decrease in motor performance: on rotarod and grip strength meter. The neuronal activity of the motor cortex negatively correlated with the duration of ALS symptoms at the time of lumbar puncture. Although the effect of ALS-CSF was more pronounced at 24h following infusion, the changes observed in LFPs and motor performance appeared to revert to baseline values at later time points of testing. In the current study, we have shown that, ALS-CSF has the potential to perturb neuronal activity of the rat motor cortex which was associated with poor performance on motor function tests.

Efficiency Characteristics of Low Power Hybrid Switched Reluctance Motor

DEFF Research Database (Denmark)

Jakobsen, Uffe; Ahn, Jin-Woo

2009-01-01

Switched reluctance motors (SRM) are usually considered inferior in terms of efficiency as compared to permanent magnet synchronous motors (PMSM) and brushless DC-motors (BLDC), but less costly. This article presents a test of a 70W hybrid switched reluctance motor (HSRM), that archieves a peak...... efficiency for the motor drive of more than 74%, and an efficiency for the motor of almost 80%....

Long-term progressive motor skill training enhances corticospinal excitability for the ipsilateral hemisphere and motor performance of the untrained hand

DEFF Research Database (Denmark)

Christiansen, Lasse; Larsen, Malte Nejst; Grey, Michael James

2017-01-01

It is well-established that unilateral motor practice can lead to increased performance in the opposite non-trained hand. Here, we test the hypothesis that progressively increasing task difficulty during long-term skill training with the dominant right hand increase performance and corticomotor...... and accuracy to individual proficiency promotes motor skill learning and drives the iM1-CSE resulting in enhanced performance of the non-trained hand. The results underline the importance of increasing task difficulty progressively and individually in skill learning and rehabilitation training. This article...... excitability of the left non-trained hand. Subjects practiced a visuomotor tracking task engaging right digit V for 6 weeks with either progressively increasing task difficulty (PT) or no progression (NPT). Corticospinal excitability(CSE) was evaluated from the resting motor threshold(rMT) and recruitment...

Long-term progressive motor skill training enhances corticospinal excitability for the ipsilateral hemisphere and motor performance of the untrained hand

DEFF Research Database (Denmark)

Christiansen, Lasse; Larsen, Malte Nejst; Grey, Michael James

2017-01-01

It is well established that unilateral motor practice can lead to increased performance in the opposite non-trained hand. Here, we test the hypothesis that progressively increasing task difficulty during long-term skill training with the dominant right hand increase performance and corticomotor...... demands for timing and accuracy to individual proficiency promotes motor skill learning and drives the iM1-CSE resulting in enhanced performance of the non-trained hand. The results underline the importance of increasing task difficulty progressively and individually in skill learning and rehabilitation...... excitability of the left non-trained hand. Subjects practiced a visuomotor tracking task engaging right digit V for 6 weeks with either progressively increasing task difficulty (PT) or no progression (NPT). Corticospinal excitability (CSE) was evaluated from the resting motor threshold (rMT) and recruitment...

Low Intensity Focused tDCS Over the Motor Cortex Shows Inefficacy to Improve Motor Imagery Performance

Directory of Open Access Journals (Sweden)

Irma N. Angulo-Sherman

2017-07-01

Full Text Available Transcranial direct current stimulation (tDCS is a brain stimulation technique that can enhance motor activity by stimulating the motor path. Thus, tDCS has the potential of improving the performance of brain-computer interfaces during motor neurorehabilitation. tDCS effects depend on several aspects, including the current density, which usually varies between 0.02 and 0.08 mA/cm2, and the location of the stimulation electrodes. Hence, testing tDCS montages at several current levels would allow the selection of current parameters for improving stimulation outcomes and the comparison of montages. In a previous study, we found that cortico-cerebellar tDCS shows potential of enhancing right-hand motor imagery. In this paper, we aim to evaluate the effects of the focal stimulation of the motor cortex over motor imagery. In particular, the effect of supplying tDCS with a 4 × 1 ring montage, which consists in placing an anode on the motor cortex and four cathodes around it, over motor imagery was assessed with different current densities. Electroencephalographic (EEG classification into rest or right-hand/feet motor imagery was evaluated on five healthy subjects for two stimulation schemes: applying tDCS for 10 min on the (1 right-hand or (2 feet motor cortex before EEG recording. Accuracy differences related to the tDCS intensity, as well as μ and β band power changes, were tested for each subject and tDCS modality. In addition, a simulation of the electric field induced by the montage was used to describe its effect on the brain. Results show no improvement trends on classification for the evaluated currents, which is in accordance with the observation of variable EEG band power results despite the focused stimulation. The lack of effects is probably related to the underestimation of the current intensity required to apply a particular current density for small electrodes and the relatively short inter-electrode distance. Hence, higher current

Dynamic and steady state performance comparison of line-start permanent magnet synchronous motors with interior and surface rotor magnets

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Ogbuka Cosmas

2016-03-01

Full Text Available A comprehensive comparison of the dynamic and steady state performance characteristics of permanent magnet synchronous motors (PMSM with interior and surface rotor magnets for line-start operation is presented. The dynamic model equations of the PMSM, with damper windings, are utilized for dynamic studies. Two typical loading scenarios are examined: step and ramp loading. The interior permanent magnet synchronous motor (IPMSM showed superior asynchronous performance under no load, attaining faster synchronism compared to the surface permanent magnet synchronous motor (SPMSM. With step load of 10 Nm at 2 s the combined effect of the excitation and the reluctance torque forced the IPMSM to pull into synchronism faster than the SPMSM which lacks saliency. The ability of the motors to withstand gradual load increase, in the synchronous mode, was examined using ramp loading starting from zero at 2 s. SPMSM lost synchronism at 12 s under 11 Nm load while the IPMSM sustained synchronism until 41 seconds under 40 Nm load. This clearly suggests that the IPMSM has superior load-withstand capability. The superiority is further buttressed with the steady state torque analysis where airgap torque in IPMSM is enhanced by the reluctance torque within 90° to 180° torque angle.

Motor performance and learning difficulties in schoolchildren aged 7 to 10 years old

Directory of Open Access Journals (Sweden)

J. Silva

2011-01-01

Full Text Available The general objective of this study was to evaluate the motor performance of children with and without learning difficulty indicatives. Took part in the study 406 students aged 7 to 10 years old, being 231 girls (56.9% and 175 (43.1% boys enrolled in a municipal public school in São José, Santa Catarina, Brazil. The indicative of learning difficulties was verified through the TDE, while motor performance was evaluated with the MABC. Boys without learning difficulties had better performance in the majority of the abilities evaluated, beyond an association between the indicative of motor problems with learning difficulties towards writing, arithmetic, reading, and in general. On the other hand, female students of the sample with and without any indicative of learning difficulties did not differentiate themselves as to motor abilities evaluated, with an association merely between the indicative of motor problems and reading problems. Based on the differences identified between girls and boys, results call attention to the need for future research in this area, considering gender as a differential variable in this relationship.

Design principles and optimal performance for molecular motors under realistic constraints

Science.gov (United States)

Tu, Yuhai; Cao, Yuansheng

2018-02-01

The performance of a molecular motor, characterized by its power output and energy efficiency, is investigated in the motor design space spanned by the stepping rate function and the motor-track interaction potential. Analytic results and simulations show that a gating mechanism that restricts forward stepping in a narrow window in configuration space is needed for generating high power at physiologically relevant loads. By deriving general thermodynamics laws for nonequilibrium motors, we find that the maximum torque (force) at stall is less than its theoretical limit for any realistic motor-track interactions due to speed fluctuations. Our study reveals a tradeoff for the motor-track interaction: while a strong interaction generates a high power output for forward steps, it also leads to a higher probability of wasteful spontaneous back steps. Our analysis and simulations show that this tradeoff sets a fundamental limit to the maximum motor efficiency in the presence of spontaneous back steps, i.e., loose-coupling. Balancing this tradeoff leads to an optimal design of the motor-track interaction for achieving a maximum efficiency close to 1 for realistic motors that are not perfectly coupled with the energy source. Comparison with existing data and suggestions for future experiments are discussed.

Short-term immobilization influences use-dependent cortical plasticity and fine motor performance.

Science.gov (United States)

Opie, George M; Evans, Alexandra; Ridding, Michael C; Semmler, John G

2016-08-25

Short-term immobilization that reduces muscle use for 8-10h is known to influence cortical excitability and motor performance. However, the mechanisms through which this is achieved, and whether these changes can be used to modify cortical plasticity and motor skill learning, are not known. The purpose of this study was to investigate the influence of short-term immobilization on use-dependent cortical plasticity, motor learning and retention. Twenty-one adults were divided into control and immobilized groups, both of which underwent two experimental sessions on consecutive days. Within each session, transcranial magnetic stimulation (TMS) was used to assess motor-evoked potential (MEP) amplitudes, short- (SICI) and long-interval intracortical inhibition (LICI), and intracortical facilitation (ICF) before and after a grooved pegboard task. Prior to the second training session, the immobilized group underwent 8h of left hand immobilization targeting the index finger, while control subjects were allowed normal limb use. Immobilization produced a reduction in MEP amplitudes, but no change in SICI, LICI or ICF. While motor performance improved for both groups in each session, the level of performance was greater 24-h later in control, but not immobilized subjects. Furthermore, training-related MEP facilitation was greater after, compared with before, immobilization. These results indicate that immobilization can modulate use-dependent plasticity and the retention of motor skills. They also suggest that changes in intracortical excitability are unlikely to contribute to the immobilization-induced modification of cortical excitability. Copyright © 2016. Published by Elsevier Ltd.

Effects of interactive games on motor performance in children with spastic cerebral palsy

OpenAIRE

AlSaif, Amer A.; Alsenany, Samira

2015-01-01

[Purpose] Motor control and muscle strength impairments are the prime reasons for motor behavior disorders in children with spastic cerebral palsy. These impairments lead to histological changes in muscle growth and the learning of motor skills. Therefore, such children experience reduced muscle force generation and decreased muscle flexibility. We investigated the effect of training with Nintendo Wii Fit games on motor performance in children with spastic cerebral palsy. [Subjects and Method...

Priming of disability and elderly stereotype in motor performance: similar or specific effects?

Science.gov (United States)

Ginsberg, Frederik; Rohmer, Odile; Louvet, Eva

2012-04-01

In three experimental studies, the effects of priming participants with the disability stereotype were investigated with respect to their subsequent motor performance. Also explored were effects of activating two similar stereotypes, persons with a disability and elderly people. In Study 1, participants were primed with the disability stereotype versus with a neutral prime, and then asked to perform on a motor coordination task. In Studies 2 and 3, a third condition was introduced: priming participants with the elderly stereotype. Results indicated that priming participants with the disability stereotype altered their motor performance: they showed decreased manual dexterity and performed slower than the non-primed participants. Priming with the elderly stereotype decreased only performance speed. These findings underline that prime-to-behavior effects may depend on activation of specific stereotype content.

Low motor performance scores among overweight children: poor coordination or morphological constraints?

Science.gov (United States)

Chivers, Paola; Larkin, Dawne; Rose, Elizabeth; Beilin, Lawrence; Hands, Beth

2013-10-01

This study examined whether lower motor performance scores can be full attributed to poor coordination, or whether weight related morphological constraints may also affect motor performance. Data for 666 children and adolescents from the longitudinal Western Australian Pregnancy Cohort (Raine) Study were grouped into normal weight, overweight and obese categories based on the International Obesity Task Force cut points. Participants completed the 10-item McCarron Assessment of Neuromuscular Development (MAND) at the 10 and 14 year follow-up. The prevalence of overweight and obese participants classified with mild or moderate motor difficulties was not different from the normal weight group at 10 years (χ2 = 5.8 p = .215), but higher at 14 years (χ2 = 11.3 p = .023). There were no significant differences in overall motor performance scores between weight status groups at 10 years, but at 14 years, the normal weight group achieved better scores than the obese group (pobese groups on the jump task at 10 (pmotor competence are appropriate for an increasingly overweight and obese population. Copyright © 2013 Elsevier B.V. All rights reserved.

Visual Motor and Perceptual Task Performance in Astigmatic Students

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Erin M. Harvey

2017-01-01

Full Text Available Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism < 1.00 D, myopia < 0.75 D, hyperopia < 2.50 D, and anisometropia < 1.50 D or bilateral astigmatism group (right and left eye ≥ 1.00 D based on cycloplegic refraction. Students completed the Beery-Buktenica Developmental Test of Visual Motor Integration (VMI and Visual Perception (VMIp. Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88. Mean VMI score in corrected astigmats did not differ from the control group (p=0.829. Uncorrected astigmats had lower VMI scores than the control group (p=0.038 and corrected astigmats (p=0.007. Mean VMIp scores for uncorrected (p=0.209 and corrected astigmats (p=0.124 did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p=0.003. Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction.

Sex differences in anthropometric characteristics, motor and cognitive functioning in preschool children at the time of school enrolment.

Science.gov (United States)

Bala, Gustav; Katić, Ratko

2009-12-01

The study included a sample of 333 preschool children (162 male and 171 female) at the time of school enrolment. Study subjects were recruited from the population of children in kindergartens in the cities of Novi Sad, Sombor, Sremska Mitrovica and Backa Palanka (Province of Voivodina, Serbia). Eight anthropometric variables, seven motor variables and one cognitive variable were analyzed to identify quantitative and qualitative sex differences in anthropometric characteristics, motor and cognitive functioning. Study results showed statistically significant sex differences in anthropometric characteristics and motor abilities in favor of male children, whereas no such difference was recorded in cognitive functioning. Sex differences found in morphological and motor spaces contributed to structuring proper general factors according to space and sex. Somewhat stronger structures were observed in male children. The cognitive aspect of functioning yielded better correlation with motor functioning in female than in male children. Motor functioning correlated better with morphological growth and development in male children, whereas cognitive functioning was relatively independent. These results are not fully in accordance with the current concept of general conditions in preschool children, nor they fully confirm the theory of integral development of children, hence they should be re-examined in future studies. Although these study results cannot be applied to sports practice in general, since we believe that it is too early for preschool children to take up sports and sport competitions, they are relevant for pointing to the need of developing general motor ability and motor behavior in preschool children.

Evidence That Bimanual Motor Timing Performance Is Not a Significant Factor in Developmental Stuttering

Science.gov (United States)

Hilger, Allison I.; Zelaznik, Howard; Smith, Anne

2016-01-01

Purpose: Stuttering involves a breakdown in the speech motor system. We address whether stuttering in its early stage is specific to the speech motor system or whether its impact is observable across motor systems. Method: As an extension of Olander, Smith, and Zelaznik (2010), we measured bimanual motor timing performance in 115 children: 70…

Motor performance of tongue with a computer-integrated system under different levels of background physical exertion

Science.gov (United States)

Huo, Xueliang; Johnson-Long, Ashley N.; Ghovanloo, Maysam; Shinohara, Minoru

2015-01-01

The purpose of this study was to compare the motor performance of tongue, using Tongue Drive System, to hand operation for relatively complex tasks under different levels of background physical exertion. Thirteen young able-bodied adults performed tasks that tested the accuracy and variability in tracking a sinusoidal waveform, and the performance in playing two video games that require accurate and rapid movements with cognitive processing using tongue and hand under two levels of background physical exertion. Results show additional background physical activity did not influence rapid and accurate displacement motor performance, but compromised the slow waveform tracking and shooting performances in both hand and tongue. Slow waveform tracking performance by the tongue was compromised with an additional motor or cognitive task, but with an additional motor task only for the hand. Practitioner Summary We investigated the influence of task complexity and background physical exertion on the motor performance of tongue and hand. Results indicate the task performance degrades with an additional concurrent task or physical exertion due to the limited attentional resources available for handling both the motor task and background exertion. PMID:24003900

Motor Skill Performance and Sports Participation in Deaf Elementary School Children

Science.gov (United States)

Hartman, Esther; Houwen, Suzanne; Visscher, Chris

2011-01-01

This study aimed to examine motor performance in deaf elementary school children and its association with sports participation. The population studied included 42 deaf children whose hearing loss ranged from 80 to 120 dB. Their motor skills were assessed with the Movement Assessment Battery for Children, and a questionnaire was used to determine…

Recruitment and derecruitment characteristics of motor units in a hand muscle of young and old adults.

Science.gov (United States)

Jesunathadas, Mark; Marmon, Adam R; Gibb, James M; Enoka, Roger M

2010-06-01

The significant decline in motor neuron number after approximately 60 yr of age is accompanied by a remodeling of the neuromuscular system so that average motor unit force increases and the ability of old adults to produce an intended force declines. One possible explanation for the loss of movement precision is that the remodeling increases the difference in recruitment forces between successively recruited motor units in old adults and this augments force variability at motor unit recruitment. The purpose of the study was to compare the forces and discharge characteristics of motor units in a hand muscle of young and old adults at motor unit recruitment and derecruitment. The difference in recruitment force between pairs of motor units did not differ between young (n=54) and old adults (n=56; P=0.702). However, old adults had a greater proportion of contractions in which motor units discharged action potentials transiently before discharging continuously during the ramp increase in force (young: 0.32; old: 0.41; P=0.045). Force variability at motor unit recruitment was greater for old adults compared with young adults (Por=0.729). These results suggest that the difference in force between the recruitment of successive motor units does not differ between age groups, but that motor unit recruitment may be more transient and could contribute to the greater variability in force observed in old adults during graded ramp contractions.

the steady-state performance characteristics of single phase transfer

African Journals Online (AJOL)

2012-11-03

Nov 3, 2012 ... field (SPTF) machine operating in the asynchronous mode from which the performance charac- teristics could be ... motor from a poly-phase induction motor by discon- necting one of its .... tating magnetic field. The pulsating ...

Motor Decline in Clinically Presymptomatic Spinocerebellar Ataxia Type 2 Gene Carriers

Science.gov (United States)

Velázquez-Perez, Luis; Díaz, Rosalinda; Pérez-González, Ruth; Canales, Nalia; Rodríguez-Labrada, Roberto; Medrano, Jacquelín; Sánchez, Gilberto; Almaguer-Mederos, Luis; Torres, Cira; Fernandez-Ruiz, Juan

2009-01-01

Background Motor deficits are a critical component of the clinical characteristics of patients with spinocerebellar ataxia type 2. However, there is no current information on the preclinical manifestation of those motor deficits in presymptomatic gene carriers. To further understand and characterize the onset of the clinical manifestation in this disease, we tested presymptomatic spinocerebellar ataxia type 2 gene carriers, and volunteers, in a task that evaluates their motor performance and their motor learning capabilities. Methods and Findings 28 presymptomatic spinocerebellar ataxia type 2 gene carriers and an equal number of control volunteers matched for age and gender participated in the study. Both groups were tested in a prism adaptation task known to be sensible to both motor performance and visuomotor learning deficits. Our results clearly show that although motor learning capabilities are intact, motor performance deficits are present even years before the clinical manifestation of the disease start. Conclusions The results show a clear deficit in motor performance that can be detected years before the clinical onset of the disease. This motor performance deficit appears before any motor learning or clinical manifestations of the disease. These observations identify the performance coefficient as an objective and quantitative physiological biomarker that could be useful to assess the efficiency of different therapeutic agents. PMID:19401771

Quantitative differences in motor abilities and basic anthropometrics characteristics of boys and girls from fourth grade of primary school

Directory of Open Access Journals (Sweden)

Buišić Svetlana

2013-01-01

Full Text Available In order to determine the quantitative differences in motor abilities and basic anthropometric characteristics by gender, we were testing 123 students of the primary school (fourth grade, 10,5 years old. Testing was applied technique of research. Two basic anthropometric measures and 14 motor tests were selected for measuring instruments. Using canonical discriminant analysis leads to results which indicate the presence of statistically significant quantitative differences in motor abilities of boys and girls but not in the anthropometric chararacteristics. Boys were in almost all motor variables statistically significantly better, except in variables for evaluation of flexibility which is more expressed by girls, but in the anthropometric characteristics there is no statistically significant differences relating to gender. Based on research results it is deduced that we need to differentiate primary students of the fourth grade by gender, because of the different levels of motor skills. Fourth grade students do not only need different approach to the work, they also need more frequent physical activity which is indispensable for development and growth.

Synchronization of motor unit firings: an epiphenomenon of firing rate characteristics not common inputs.

Science.gov (United States)

Kline, Joshua C; De Luca, Carlo J

2016-01-01

Synchronous motor unit firing instances have been attributed to anatomical inputs shared by motoneurons. Yet, there is a lack of empirical evidence confirming the notion that common inputs elicit synchronization under voluntary conditions. We tested this notion by measuring synchronization between motor unit action potential trains (MUAPTs) as their firing rates progressed within a contraction from a relatively low force level to a higher one. On average, the degree of synchronization decreased as the force increased. The common input notion provides no empirically supported explanation for the observed synchronization behavior. Therefore, we investigated a more probable explanation for synchronization. Our data set of 17,546 paired MUAPTs revealed that the degree of synchronization varies as a function of two characteristics of the motor unit firing rate: the similarity and the slope as a function of force. Both are measures of the excitation of the motoneurons. As the force generated by the muscle increases, the firing rate slope decreases, and the synchronization correspondingly decreases. Different muscles have motor units with different firing rate characteristics and display different amounts of synchronization. Although this association is not proof of causality, it consistently explains our observations and strongly suggests further investigation. So viewed, synchronization is likely an epiphenomenon, subject to countless unknown neural interactions. As such, synchronous firing instances may not be the product of a specific design and may not serve a specific physiological purpose. Our explanation for synchronization has the advantage of being supported by empirical evidence, whereas the common input does not. Copyright © 2016 the American Physiological Society.

Motor performance of children with mild intellectual disability and borderline intellectual functioning

NARCIS (Netherlands)

Vuijk, P. J.; Hartman, E.; Scherder, E.; Visscher, C.

2010-01-01

Background There is a relatively small body of research on the motor performance of children with mild intellectual disabilities (MID) and borderline intellectual functioning (BIF). Adequate levels of motor skills may contribute to lifelong enjoyment of physical activity, participation in sports and

Static Analysis of High-Performance Fixed Fluid Power Drive with a Single Positive-Displacement Hydraulic Motor

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O. F. Nikitin

2015-01-01

Full Text Available The article deals with the static calculations in designing a high-performance fixed fluid power drive with a single positive-displacement hydraulic motor. Designing is aimed at using a drive that is under development and yet unavailable to find and record the minimum of calculations and maximum of existing hydraulic units that enable clear and unambiguous performance, taking into consideration an available assortment of hydraulic units of hydraulic drives, to have the best efficiency.The specified power (power, moment and kinematics (linear velocity or angular velocity of rotation parameters of the output element of hydraulic motor determine the main output parameters of the hydraulic drive and the useful power of the hydraulic drive under development. The value of the overall efficiency of the hydraulic drive enables us to judge the efficiency of high-performance fixed fluid power drive.The energy analysis of a diagram of the high-performance fixed fluid power drive shows that its high efficiency is achieved when the flow rate of fluid flowing into each cylinder and the magnitude of the feed pump unit (pump are as nearly as possible.The paper considers the ways of determining the geometric parameters of working hydromotors (effective working area or working volume, which allow a selection of the pumping unit parameters. It discusses the ways to improve hydraulic drive efficiency. Using the principle of holding constant conductivity allows us to specify the values of the pressure losses in the hydraulic units used in noncatalog modes. In case of no exact matching between the parameters of existing hydraulic power modes and a proposed characteristics of the pump unit, the nearest to the expected characteristics is taken as a working version.All of the steps allow us to create the high-performance fixed fluid power drive capable of operating at the required power and kinematic parameters with high efficiency.

Motor skills, cognition, and work performance of people with severe mental illness.

Science.gov (United States)

Lipskaya-Velikovsky, Lena; Elgerisi, Dikla; Easterbrook, Adam; Ratzon, Navah Z

2018-01-12

Employment offers many benefits to people with mental illness, yet their employment rate is much lower than that of the general population. We investigated the effect of work-related motor skills, neurocognition, and job attitudes on the work performance of people with mental illness, comparing those working in sheltered workshops, with controls working in similar jobs. Twenty-nine adults with severe mental illness and 27 controls matched by gender and age were enrolled into the study using convenience sampling. They were assessed for gross and fine motor hand functioning, job attitudes, work performance, and cognition. People with mental illness scored lower on work performance, cognitive functioning, and hand dexterity while sitting and working with tools. They were assigned lower job loads than were controls, and perceived the physical environment at work as more constraining than did controls. Assembling motor skills significantly explained the work performance of people with mental illness. The results expand our understanding of the complexities involved in the employment of people with severe mental illness, and point to new paths for improving vocational outcomes of people with severe mental illness, taking into account their motor skills and job attitudes. Implications for rehabilitation Therapists should be aware that employed people with severe mental illness may have various unmet needs, affecting their work performance and experience of stress. This study results demonstrate importance of motor skills and perception of the work environment for the promotion of vocational outcomes among individuals with severe mental illness. Employment of people with severe mental illness should be viewed from holistic perspective as with general population, rather than focused on traditionally illness-related factors.

The role of rotational hand movements and general motor ability in children’s mental rotation performance

Directory of Open Access Journals (Sweden)

Petra eJansen

2015-07-01

Full Text Available Mental rotation of visual images of body parts and abstract shapes can be influenced by simultaneous motor activity. Children in particular seem to have a strong coupling between motor and cognitive processes. We investigated the influence of a rotational hand movement performed by rotating a knob on mental rotation performance in primary school-age children (N= 83; Age range: 7.0-8.3 and 9.0-10.11 years. In addition, we assessed the role of motor ability in this relationship. Boys in the 7-8-year-old group were faster when mentally and manually rotating in the same direction than in the opposite direction. For girls and older children this effect was not found. A positive relationship was found between motor ability and accuracy on the mental rotation task: stronger motor ability related to improved mental rotation performance. In both age groups, children with more advanced motor abilities were more likely to adopt motor processes to solve mental rotation tasks if the mental rotation task was primed by a motor task. Our evidence supports the idea that an overlap between motor and visual cognitive processes in children is influenced by motor ability.

STUDYING THE EFFECT OF AN ADDITIONAL ACTIVE RESISTANCE IN THE FIELD WINDING CIRCUIT ON STARTING CHARACTERISTICS OF SALIENT-POLE SYNCHRONOUS MOTORS

Directory of Open Access Journals (Sweden)

V. S. Malyar

2018-04-01

Full Text Available On the basis of the developed method for calculating steady-state asynchronous operation modes of salient-pole synchronous motors, a procedure of mathematical modelling of the starting characteristics is proposed. The problem of calculating the steady-state asynchronous mode is solved as a boundary value one for differential equations of motor circuit electrical equilibrium. Algebraization of the system of differential equations is carried out by approximating the equations of state using cubic spline functions on a grid of period nodes, taking into account the periodic law of variation of the coordinates. This results in the changeover from continual values to nodal ones. The starting static characteristics are calculated using the parameter continuation method. The study of the effect of the starting resistance value on the asynchronous characteristics of the motor relied on a mathematical model of the motor taking into consideration real field circuits, saturation and asymmetry of the magnetic path.

RELATIONS OF CONSTITUTIONAL CHARACTERISTICS AND MOTORIC ABILITIES OF SERBIA AND MONTENEFRO AND MONTENEGRO

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Ivan Terzić

2011-08-01

Full Text Available Handball is the one of the most important sports in this region for many years. Althought being a host of European chamiponship 2010, Montenegro didn’t fulfill expectations, neither of fans, neither of professional comunity, only reaching 17th place. Couple of years before, male cadet handball selection Sebia and Montenegro had achieved great succes conquered the title of European (2004 and World champion (2005. Since representatives of Montenegro have consisted a significant part of that team, we tried to compare some of constitutional characteristics (weight, height and planimetry of hand and 10 motorical abilities of these two selections. Sample consisted of 20 representatives male cadet handball selection of Sebia and Montenegro and 16 male cadet handball selection Montenegro. We used t test for independent samples. Our results showed that there were statisticaly significant differences at planimetry of hand, agility test, speed test, long jump, triple jump, repetitive trunk flexor strength and hand taping. Representatives of Montenego had better results only on the test of hand taping. Also, we tried to find out, by use of Pearson correlation coefficient, which of anthropometic characteristics and motorical abilities could participate in succes of Serbia and Montenegro team and compare them with relationships obtained at the sample of Montenegro’s representatives. Results showed that there were some statisticaly significant correlations between anthropometrical characteristics and motorical abilities. Only one correlation was the common at both samples, the one between long jump and triple jump, and it was stronger at sample of Montenegro cadets. These results confirmed our assumption about usefulness of standards which were created by trophy cadet selection of Sebia and Montenegro for planing and creating work programmes for Montenegro handball team and also in process of selection of players for national team

Transcranial direct current stimulation (tDCS) to the supplementary motor area (SMA) influences performance on motor tasks.

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Hupfeld, K E; Ketcham, C J; Schneider, H D

2017-03-01

The supplementary motor area (SMA) is believed to be highly involved in the planning and execution of both simple and complex motor tasks. This study aimed to examine the role of the SMA in planning the movements required to complete reaction time, balance, and pegboard tasks using anodal transcranial direct current stimulation (tDCS), which passes a weak electrical current between two electrodes, in order to modulate neuronal activity. Twenty healthy adults were counterbalanced to receive either tDCS (experimental condition) or no tDCS (control condition) for 3 days. During administration of tDCS, participants performed a balance task significantly faster than controls. After tDCS, subjects significantly improved their simple and choice reaction time. These results demonstrate that the SMA is highly involved in planning and executing fine and gross motor skill tasks and that tDCS is an effective modality for increasing SMA-related performance on these tasks. The findings may be generalizable and therefore indicate implications for future interventions using tDCS as a therapeutic tool.

Mental workload and motor performance dynamics during practice of reaching movements under various levels of task difficulty.

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Shuggi, Isabelle M; Oh, Hyuk; Shewokis, Patricia A; Gentili, Rodolphe J

2017-09-30

The assessment of mental workload can inform attentional resource allocation during task performance that is essential for understanding the underlying principles of human cognitive-motor behavior. While many studies have focused on mental workload in relation to human performance, a modest body of work has examined it in a motor practice/learning context without considering individual variability. Thus, this work aimed to examine mental workload by employing the NASA TLX as well as the changes in motor performance resulting from the practice of a novel reaching task. Two groups of participants practiced a reaching task at a high and low nominal difficulty during which a group-level analysis assessed the mental workload, motor performance and motor improvement dynamics. A secondary cluster analysis was also conducted to identify specific individual patterns of cognitive-motor responses. Overall, both group- and cluster-level analyses revealed that: (i) all participants improved their performance throughout motor practice, and (ii) an increase in mental workload was associated with a reduction of the quality of motor performance along with a slower rate of motor improvement. The results are discussed in the context of the optimal challenge point framework and in particular it is proposed that under the experimental conditions employed here, functional task difficulty: (i) would possibly depend on an individuals' information processing capabilities, and (ii) could be indexed by the level of mental workload which, when excessively heightened can decrease the quality of performance and more generally result in delayed motor improvements. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Motor-cognitive dual-task performance: effects of a concurrent motor task on distinct components of visual processing capacity.

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Künstler, E C S; Finke, K; Günther, A; Klingner, C; Witte, O; Bublak, P

2018-01-01

Dual tasking, or the simultaneous execution of two continuous tasks, is frequently associated with a performance decline that can be explained within a capacity sharing framework. In this study, we assessed the effects of a concurrent motor task on the efficiency of visual information uptake based on the 'theory of visual attention' (TVA). TVA provides parameter estimates reflecting distinct components of visual processing capacity: perceptual threshold, visual processing speed, and visual short-term memory (VSTM) storage capacity. Moreover, goodness-of-fit values and bootstrapping estimates were derived to test whether the TVA-model is validly applicable also under dual task conditions, and whether the robustness of parameter estimates is comparable in single- and dual-task conditions. 24 subjects of middle to higher age performed a continuous tapping task, and a visual processing task (whole report of briefly presented letter arrays) under both single- and dual-task conditions. Results suggest a decline of both visual processing capacity and VSTM storage capacity under dual-task conditions, while the perceptual threshold remained unaffected by a concurrent motor task. In addition, goodness-of-fit values and bootstrapping estimates support the notion that participants processed the visual task in a qualitatively comparable, although quantitatively less efficient way under dual-task conditions. The results support a capacity sharing account of motor-cognitive dual tasking and suggest that even performing a relatively simple motor task relies on central attentional capacity that is necessary for efficient visual information uptake.

Carbon monoxide exposure and information processing during perceptual-motor performance

Energy Technology Data Exchange (ETDEWEB)

Mihevic, P.M.; Gliner, J.A.; Horvath, S.M.

1983-01-01

This study examined the influence of exposure to ambient carbon monoxide resulting in final carboxyhemoglobin (COHb) levels of approximately 5.0% on the ability to process information during motor performance. Subjects (n . 16) performed a primary reciprocal tapping task and a secondary digit manipulation task singly and/or concurrently during 2.5 h exposure to room air (0 ppm CO) or 100 ppm CO. Five levels of tapping difficulty and two levels of digit manipulation were employed. Tapping performance was unaffected when COHb levels were as high as 5%. However, at this level of COHb it was noted that CO exposure interacted with task difficulty of both tasks to influence reaction time on the digit manipulation task. It was concluded that motor performance was not influenced by exposure to CO leading to COHb concentrations of 5%. Task difficulty was a significant factor mediating behavioral effects of CO exposure.

Carbon monoxide exposure and information processing during perceptual-motor performance

Energy Technology Data Exchange (ETDEWEB)

Mihevic, P.M.; Gliner, J.A.; Horvath, S.M.

1983-04-01

This study examined the influence of exposure to ambient carbon monoxide resulting in final carboxyhemoglobin (COHb) levels of approximately 5.0% on the ability to process information during motor performance. Subjects (n = 16) performed a primary reciprocal tapping task and a secondary digit manipulation task singly and/or concurrently during 2.5 h exposure to room air (0 ppm CO) or 100 ppm CO. Five levels of tapping difficulty and two levels of digit manipulation were employed. Tapping performance was unaffected when COHb levels were as high as 5%. However, at this level of COHb it was noted that CO exposure interacted with task difficulty of both tasks to influence reaction time on the digit manipulation task. It was concluded that motor performance was not influenced by exposure to CO leading to COHb concentrations of 5%. Task difficulty was a significant factor mediating behavioral effects of CO exposure.

Optimization of a piezoelectric linear motor in terms of the contact parameters

International Nuclear Information System (INIS)

Ko, Hyun-Phill; Kim, Sangsig; Kang, Chong-Yun; Kim, Hyun-Jai; Yoon, Seok-Jin

2005-01-01

The contact kinetics of piezoelectric linear motors determines the operational characteristics like speed and torque or transmitted mechanical power and efficiency. Piezoelectric linear motors are driven by tangential stress in the interface between tip of shaking beam and slider. A good contact between the tip and slider is necessary for a reliable analysis of the motor, which is needed for the optimization of its performance. The piezoelectric linear motor was fabricated and the characteristics of the motor were investigated by external conditions such as tip shape with different curvatures and contact force between the tip and the slider. It was found in this investigation that the optimal curvature of the tip and the contact force are curvature of 1 and 10, respectively, for the high actuating speed, and curvature of 1 and 40 N, respectively, for the high actuating force. Finally, tip shape has an influence on the characteristics of linear motor

Slot Optimization Design of Induction Motor for Electric Vehicle

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Shen, Yiming; Zhu, Changqing; Wang, Xiuhe

2018-01-01

Slot design of induction motor has a great influence on its performance. The RMxprt module based on magnetic circuit method can be used to analyze the influence of rotor slot type on motor characteristics and optimize slot parameters. In this paper, the authors take an induction motor of electric vehicle for a typical example. The first step of the design is to optimize the rotor slot by RMxprt, and then compare the main performance of the motor before and after the optimization through Ansoft Maxwell 2D. After that, the combination of optimum slot type and the optimum parameters are obtained. The results show that the power factor and the starting torque of the optimized motor have been improved significantly. Furthermore, the electric vehicle works at a better running status after the optimization.

Effects of glycine on motor performance in rats after traumatic spinal cord injury.

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Gonzalez-Piña, Rigoberto; Nuño-Licona, Alberto

2007-01-01

It has been reported that glycine improves some functions lost after spinal cord injury (SCI). In order to assess the effects of glycine administration on motor performance after SCI, we used fifteen male Wistar rats distributed into three groups: sham (n = 3), spinal-cord injury (n = 6,) and spinal cord injury + glycine (n = 6). Motor performance was assessed using the beam-walking paradigm and footprint analysis. Results showed that for all animals with spinal-cord injury, scores in the beam-walking increased, which is an indication of increased motor deficit. In addition, footprint analysis showed a decrease in stride length and an increase in stride angle, additional indicators of motor deficit. These effects trended towards recovery after 8 weeks of recording and trended toward improvement by glycine administration; the effect was not significant. These results suggest that glycine replacement alone is not sufficient to improve the motor deficits that occur after SCI.

Physical and Motor Performance Predictors of Lower Body ...

African Journals Online (AJOL)

The aim of this study was to develop a lower body explosive power (LBEP) prediction model from various physical and motor performance components among a cohort of male and female adolescents living in the Tlokwe local municipality of the North-West Province. A cross-sectional experimental research design was ...

Performance analysis of samarium cobalt P.M. synchronous motor fed from PWM inverters

International Nuclear Information System (INIS)

Rahman, M.A.; Choudhury, M.A.

1985-01-01

This paper presents an analysis and performance of samarium cobalt permanent magnet (P.M.) synchronous motors fed from two types of voltage source pulse width modulated (PWM) inverters. The analysis and test results on the steady state performance of a P.M. motor fed from PWM inverters are presented. PWM inverters are used in variable voltage variable frequency applications to avoid a double conversion process of ordinary inverters. In drives, they are used for voltage and speed regulation of motors. Use of modulation technique in inverters also allow to eliminate or minimize selected harmonics from the inverter output voltage

Human θ burst stimulation enhances subsequent motor learning and increases performance variability.

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Teo, James T H; Swayne, Orlando B C; Cheeran, Binith; Greenwood, Richard J; Rothwell, John C

2011-07-01

Intermittent theta burst stimulation (iTBS) transiently increases motor cortex excitability in healthy humans by a process thought to involve synaptic long-term potentiation (LTP), and this is enhanced by nicotine. Acquisition of a ballistic motor task is likewise accompanied by increased excitability and presumed intracortical LTP. Here, we test how iTBS and nicotine influences subsequent motor learning. Ten healthy subjects participated in a double-blinded placebo-controlled trial testing the effects of iTBS and nicotine. iTBS alone increased the rate of learning but this increase was blocked by nicotine. We then investigated factors other than synaptic strengthening that may play a role. Behavioral analysis and modeling suggested that iTBS increased performance variability, which correlated with learning outcome. A control experiment confirmed the increase in motor output variability by showing that iTBS increased the dispersion of involuntary transcranial magnetic stimulation-evoked thumb movements. We suggest that in addition to the effect on synaptic plasticity, iTBS may have facilitated performance by increasing motor output variability; nicotine negated this effect on variability perhaps via increasing the signal-to-noise ratio in cerebral cortex.

Effect of the home environment on motor and cognitive behavior of infants.

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Miquelote, Audrei F; Santos, Denise C C; Caçola, Priscila M; Montebelo, Maria Imaculada de L; Gabbard, Carl

2012-06-01

Although information is sparse, research suggests that affordances in the home provide essential resources that promote motor and cognitive skills in young children. The present study assessed over time, the association between motor affordances in the home and infant motor and cognitive behavior. Thirty-two (32) infants were assessed for characteristics of their home using the Affordances in the Home Environment for Motor Development--Infant Scale and motor and cognitive behavior with the Bayley Scales of Infant and Toddler Development--III. Infant's home and motor behavior were assessed at age 9 months and 6 months later with the inclusion of cognitive ability. Results for motor ability indicated that there was an overall improvement in performance from the 1st to the 2nd assessment. We found significant positive correlations between the dimensions of the home (daily activities and play materials) and global motor performance (1st assessment) and fine-motor performance on the 2nd assessment. In regard to cognitive performance (2nd assessment), results indicated a positive association with fine-motor performance. Our results suggest that motor affordances can have a positive impact on future motor ability and speculatively, later cognitive behavior in infants. Copyright © 2012 Elsevier Inc. All rights reserved.

The performance and efficiency of four motor/controller/battery systems for the simpler electric vehicles

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Shipps, P. R.

1980-01-01

A test and analysis program performed on four complete propulsion systems for an urban electric vehicle (EV) is described and results given. A dc series motor and a permanent magnet (PM) motor were tested, each powered by an EV battery pack and controlled by (1) a series/parallel voltage-switching (V-switch) system; and (2) a system using a pulse width modulation, 400 Hz transistorized chopper. Dynamometer tests were first performed, followed by eV performance predictions and data correlating road tests. During dynamometer tests using chopper control; current, voltage, and power were measured on both the battery and motor sides of the chopper, using three types of instrumentation. Conventional dc instruments provided adequate accuracy for eV power and energy measurements, when used on the battery side of the controller. When using the chopper controller, the addition of a small choke inductor improved system efficiency in the lower duty cycle range (some 8% increase at 50% duty cycle) with both types of motors. Overall system efficiency rankings during road tests were: (1) series motor with V-switch; (2) PM motor with V-switch; (3) series motor with chopper; and (4) PM motor with chopper. Chopper control of the eV was smoother and required less driver skill than V-switch control.

Anthropometric and motor performance profile of elite futsal athletes

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Leandro Ricardo Altimari

2008-01-01

Full Text Available The purpose of the present study was to identify the anthropometric and motor performance profile of futsal (indoor soccer athletes in the second and third-placed teams in the Parana state championships (Brazil. Anthropometric (body mass, stature and skinfolds thickness and motor performance (modified abdominal test, shuttle run, race of 30 m and 40 s measures were obtained from twenty-seven male athletes (24.7 ± 6.4 years; 73.6 ± 7.6 kg; 174.8 ± 6.6 cm. For data analysis, athletes were grouped according to game positions. ANOVA one-way was used for comparisons between different positions, followed by Scheffé’s post hoc test, with p ABSTRACT Este estudo objetivou identificar o perfil antropométrico e o desempenho motor de atletas de futsal masculino, pertencentes às equipes finalistas do campeonato paranaense da categoria adulto, chave ouro. Para tanto, coletou-se medidas antropométricas (massa corporal, estatura e espessura de dobras cutâneas e de desempenho motor (testes abdominal modificado, shuttle run, corrida de 30 m e corrida de 40 s de vinte e sete atletas (24,7 ± 6,4 anos; 73,6 ± 7,6 kg; 174,8 ± 6,6 cm, do sexo masculino. Para a análise dos dados, agrupou-se os atletas de acordo com a posição de jogo. Anova one-way foi empregada para as comparações entre os jogadores das diferentes posições, seguida pelo teste post hoc de Scheffé, com P < 0,05. Verificou-se diferença signifi cante entre os jogadores de diferentes posições de jogo nas variáveis: massa corporal (alas < goleiros, P < 0,01, estatura (alas < pivôs e goleiros, P < 0,01 e massa corporal magra (alas < goleiros, P < 0,01. Não foram observadas diferenças significantes entre os jogadores das diferentes posições de jogo nas variáveis de desempenho motor. Os resultados encontrados no presente estudo sugerem que atletas de futsal apresentam, na maioria das variáveis analisadas, características antropométricas e de desempenho motor semelhantes entre

Evaluation of some physical and motoric characteristics of athletes with down syndrome

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Ilkım Mehmet

2017-01-01

Full Text Available The aim of this study was to evaluate some physical and motoric characteristics of Down’s syndrome athletes. The sample of the study consists of 60 athletes (n=30 experimetal group and n=30 control group who are in the Malatya Sessiz Adımlar Sports Club, aged between 13 and 15. Athletes in the experimental group were subjected to a training program to improve the balance and flexibility of 2 hours of 3 days a week for 8 weeks. The athletes, in the control group continued their usual training programs. Before and after the 8-week training program that is applicated for the athletes in the experimental group, the balance and flexibility performances of the athletes in both the experimental and control groups were determined. It was used the flamingo balance test to determine the balance performance of the athletes; was used Sit & Reach test to determine flexibility performance. In favor of the athletes who are in experimental group a statistically significant difference (p0.05 obtained between pre-test and post-test results that is applicated to determine the flexibility performance. It was also found that there was no relationship (p>0.05 between the BMI values of the athletes and their balance and flexibility performances. In the study, it was found that the training program for 8 week training to improve balance and flexibility that was applied to dealing with athleticism 13–15 age group athletes with down syndrome improved the athletes’ balance performance but did not contribute to the their improvement of flexibility performances.

The fourth dimension: A motoric perspective on the anxiety-performance relationship.

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Carson, Howie J; Collins, Dave

2016-01-01

This article focuses on raising concern that anxiety-performance relationship theory has insufficiently catered for motoric issues during, primarily, closed and self-paced skill execution (e.g., long jump and javelin throw). Following a review of current theory, we address the under-consideration of motoric issues by extending the three-dimensional model put forward by Cheng, Hardy, and Markland (2009) ('Toward a three-dimensional conceptualization of performance anxiety: Rationale and initial measurement development, Psychology of Sport and Exercise , 10 , 271-278). This fourth dimension, termed skill establishment , comprises the level and consistency of movement automaticity together with a performer's confidence in this specific process, as providing a degree of robustness against negative anxiety effects. To exemplify this motoric influence, we then offer insight regarding current theories' misrepresentation that a self-focus of attention toward an already well-learned skill always leads to a negative performance effect. In doing so, we draw upon applied literature to distinguish between positive and negative self-foci and suggest that on what and how a performer directs their attention is crucial to the interaction with skill establishment and, therefore, performance. Finally, implications for skill acquisition research are provided. Accordingly, we suggest a positive potential flow from applied/translational to fundamental/theory-generating research in sport which can serve to freshen and usefully redirect investigation into this long-considered but still insufficiently understood concept.

A Review of Standardized Tests of Nonverbal Oral and Speech Motor Performance in Children

Science.gov (United States)

McCauley, Rebecca J.; Strand, Edythe A.

2008-01-01

Purpose: To review the content and psychometric characteristics of 6 published tests currently available to aid in the study, diagnosis, and treatment of motor speech disorders in children. Method: We compared the content of the 6 tests and critically evaluated the degree to which important psychometric characteristics support the tests' use for…

Motor Performance of Children with Mild Intellectual Disability and Borderline Intellectual Functioning

Science.gov (United States)

Vuijk, P. J.; Hartman, E.; Scherder, E.; Visscher, C.

2010-01-01

Background: There is a relatively small body of research on the motor performance of children with mild intellectual disabilities (MID) and borderline intellectual functioning (BIF). Adequate levels of motor skills may contribute to lifelong enjoyment of physical activity, participation in sports and healthy lifestyles. The present study compares…

Outcome and Process in Motor Performance: A Comparison of Jumping by Typically Developing Children and Those with Low Motor Proficiency

Science.gov (United States)

Williams, Morgan D.; Saunders, John E.; Maschette, Wayne E.; Wilson, Cameron J.

2013-01-01

The motivation for this study was to explore a conceptual framework to understand the outcomes and processes of motor performance in children. Vertical jumping, a fundamental movement skill, was used to compare children (ages 6-12 years) who were typically developing (TD) and those identified as having low motor proficiency (LMP). Jumps were…

The change in perceived motor competence and motor task values during elementary school : Gender and motor performance differences

NARCIS (Netherlands)

Noordstar, J.J.; van der Net, J.; Jak, S.; Helders, P.J.M.; Jongmans, M.J.

2016-01-01

Participation in motor activities is essential for social interaction and life satisfaction in children. Self-perceptions and task values have a central position in why children do or do not participate in (motor) activities. Investigating developmental changes in motor self-perceptions and motor

The Effect of the Rotor Static Eccentricity on the Electro-Mechanical Coupled Characteristics of the Motorized Spindle

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Wu Zaixin

2016-01-01

Full Text Available High-speed motorized spindle is a multi-variable, non-linear and strong coupling system. The rotor static eccentricity is inevitable because of machining or assembling error. The rotor static eccentricities have an important effect on the electromechanical coupled characteristics of the motorized spindle. In this paper, the electromechanical coupled mathematical model of the motorized spindle was set up. The mathematical model includes mechanical and electrical equation. The mechanical and electrical equation is built up by the variational principle. Furthermore, the inductance parameters without the rotor static eccentricity and the inductance parameters with rotor static eccentricity have been calculated by the winding function method and the high speed motorized spindle was simulated. The result show that the rotor static eccentricity can delay the starting process of the motorized spindle, and at steady state, the rotor circuit currents are still large because of the rotor static eccentricity.

Motor performance as predictor of physical activity in children - The CHAMPS Study-DK

DEFF Research Database (Denmark)

Larsen, Lisbeth Runge; Kristensen, Peter Lund; Junge, Tina

2015-01-01

Purpose Physical activity is associated with several health benefits in children, and physical activity habits developed in childhood tend to persist into adulthood. Physical activity may be the foundation of a healthy lifestyle and motor performance has been shown to be positively associated wit...... run in childhood may be important determinants of physical activity in adolescence.......Purpose Physical activity is associated with several health benefits in children, and physical activity habits developed in childhood tend to persist into adulthood. Physical activity may be the foundation of a healthy lifestyle and motor performance has been shown to be positively associated...... with physical activity in cross-sectional studies. The purpose of this study was to explore the longitudinal relationship between motor performance and physical activity in a three-year follow-up study. Methods Longitudinal analyses were performed using data from 673 participants (44% boys, 6-12 years old) who...

Fine-motor skills testing and prediction of endovascular performance

DEFF Research Database (Denmark)

Bech, Bo; Lönn, Lars; Schroeder, Torben V

2013-01-01

Performing endovascular procedures requires good control of fine-motor digital movements and hand-eye coordination. Objective assessment of such skills is difficult. Trainees acquire control of catheter/wire movements at various paces. However, little is known to what extent talent plays for novice...

Peak height velocity as an alternative for maturational classification associated with motor performance

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Leonardo Trevizan Costa

2009-01-01

Full Text Available Adolescence is a phase characterized by important physical and maturational alterations, with individuals of the same chronological age, but who are more mature, may present sportive advantages because of greater force gain and additional muscle mass. Thus, in studies evaluating motor skills of children and adolescents, maturational classification should be an efficient and easily applicable tool in order to facilitate the interpretation of the true relationship between maturation and motor performance. Therefore, the objective of this study was to compare the relationship between motor performance and different types of classification of biological maturation in 209 boys aged to 17 years (11.59 ± 2.57 practicing soccer. Anthropometric variables were obtained according to the ISAK criteria. Biological maturation was determined based on age at peak height velocity (PHV and also by self-assessment of sexual maturation (genitalia and pubic hair. Motor performance was evaluated by sit-and-reach tests, horizontal jump, modified push-ups, 50-m run, and 9/12-min run/walk. The results showed progression in the variables analyzed as the subjects reached maturity. Correlation analysis and the egression values indicated higher consistency for the PHV classification, which better explained motor performance according to maturational status, exceeding the values obtained by comparison according to age or sexual maturation. Thus, the use of PHV as a classification instrument is preferably recommended for youngsters with haracteristics similar to those of the present sample.

Reduce consumption, improve production. Electronic adjustable speed drives and high performance motors; Consommez moins, produisez mieux. Variateurs electroniques de vitesse et moteurs performants

Energy Technology Data Exchange (ETDEWEB)

David, A.; Pratmarty, D.; Dessoude, M. [Electricite de France (EDF), 92 - Clamart (France). Direction des Etudes et Recherches

1995-10-01

The electric power consumption from electric motors accounts for up to two third of industry`s electric power consumption. When equipped with electronic adjustable speed drives (ASD), energy savings of 10 to 50 percent, with an estimated average of 25 percent, may be achieved for pumps, fans and compressors, which account for 63 percent of motor applications. The advantages of electronic ASD, the installation recommendations which should be applied, the sensibility of ASDs to power cuts and harmonics, the characteristics of high efficiency motors, the energy aspects of motors with or without electronic ASD, and the EDF-ADEME (French energy conservation agency) approach for electricity demand side management, are described

A novel PM motor with hybrid PM excitation and asymmetric rotor structure for high torque performance

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Gaohong Xu

2017-05-01

Full Text Available This paper proposes a novel permanent magnet (PM motor for high torque performance, in which hybrid PM material and asymmetric rotor design are applied. The hybrid PM material is adopted to reduce the consumption of rare-earth PM because ferrite PM is assisted to enhance the torque production. Meanwhile, the rotor structure is designed to be asymmetric by shifting the surface-insert PM (SPM, which is used to improve the torque performance, including average torque and torque ripple. Moreover, the reasons for improvement of the torque performance are explained by evaluation and analysis of the performances of the proposed motor. Compared with SPM motor and V-type motor, the merit of high utilization ratio of rare-earth PM is also confirmed, showing that the proposed motor can offer higher torque density and lower torque ripple simultaneously with less consumption of rare-earth PM.

Torque Ripple Minimization and Performance Investigation of an In-Wheel Permanent Magnet Motor

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A. Mansouri

2016-06-01

Full Text Available Recently, electric vehicle motoring has become a topic of interest, due to the several problems caused by thermal engines such as pollution and high oil prices. Thus, electric motors are increasingly applied in vehicle’ applications and relevant research about these motors and their applications has been performed. Of particular interest are the improvements regarding torque production capability, the minimization of torque ripple and iron losses. The present work deals with the optimum design and the performance investigation of an outer rotor permanent magnet motor for in-wheel electric vehicle application. At first, and in order to find the optimum motor design, a new based particle-swarm multi-objective optimization procedure is applied. Three objective functions are used: efficiency maximization, weight and ripple torque minimization. Secondly, the effects of the permanent magnets segmentation, the stator slots opening, and the separation of adjacent magnets by air are outlined. The aim of the paper is the design of a topology with smooth output torque, low ripple torque, low iron losses and mechanical robustness.

Characteristic analysis of a less-rare-earth hybrid PM-assisted synchronous reluctance motor for EVs application

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Wenye Wu

2017-05-01

Full Text Available Low-energy permanent magnet (PM such as ferrite is usually adopted in a PM-assisted reluctance (PMAREL motor to enhance the output torque and reduce costs. However, the relatively low magnetic energy product and remanence in such PMs may lead to the risk of demagnetization. By using two types of materials of rare-earth NdFeB and non-rare-earth ferrite PM, a new less-rare-earth hybrid PMAREL motor is proposed in this paper, where the output torque and the power factor can be improved obviously, and meanwhile the risk of irreversible demagnetization in ferrite PMs can be reduced significantly due to the existence of NdFeB PMs. To verify the validity of the proposed motor, the operating principles of the motor and the positive interaction influences between the two involved types of PMs are analyzed. Moreover, by using the finite element method, the torque characteristics and anti-demagnetization capabilities are also investigated in details. Both the theoretical analysis and simulated results confirm the advantages of the proposed motor.

Characteristic analysis of a less-rare-earth hybrid PM-assisted synchronous reluctance motor for EVs application

Science.gov (United States)

Wu, Wenye; Zhu, Xiaoyong; Quan, Li; Fan, Deyang; Xiang, Zixuan

2017-05-01

Low-energy permanent magnet (PM) such as ferrite is usually adopted in a PM-assisted reluctance (PMAREL) motor to enhance the output torque and reduce costs. However, the relatively low magnetic energy product and remanence in such PMs may lead to the risk of demagnetization. By using two types of materials of rare-earth NdFeB and non-rare-earth ferrite PM, a new less-rare-earth hybrid PMAREL motor is proposed in this paper, where the output torque and the power factor can be improved obviously, and meanwhile the risk of irreversible demagnetization in ferrite PMs can be reduced significantly due to the existence of NdFeB PMs. To verify the validity of the proposed motor, the operating principles of the motor and the positive interaction influences between the two involved types of PMs are analyzed. Moreover, by using the finite element method, the torque characteristics and anti-demagnetization capabilities are also investigated in details. Both the theoretical analysis and simulated results confirm the advantages of the proposed motor.

Theta Neurofeedback Effects on Motor Memory Consolidation and Performance Accuracy: An Apparent Paradox?

Science.gov (United States)

Reiner, Miriam; Lev, Dror D; Rosen, Amit

2018-05-15

Previous studies have shown that theta neurofeedback enhances motor memory consolidation on an easy-to-learn finger-tapping task. However, the simplicity of the finger-tapping task precludes evaluating the putative effects of elevated theta on performance accuracy. Mastering a motor sequence is classically assumed to entail faster performance with fewer errors. The speed-accuracy tradeoff (SAT) principle states that as action speed increases, motor performance accuracy decreases. The current study investigated whether theta neurofeedback could improve both performance speed and performance accuracy, or would only enhance performance speed at the cost of reduced accuracy. A more complex task was used to study the effects of parietal elevated theta on 45 healthy volunteers The findings confirmed previous results on the effects of theta neurofeedback on memory consolidation. In contrast to the two control groups, in the theta-neurofeedback group the speed-accuracy tradeoff was reversed. The speed-accuracy tradeoff patterns only stabilized after a night's sleep implying enhancement in terms of both speed and accuracy. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Awake Surgery for a Violin Player: Monitoring Motor and Music Performance, A Case Report.

Science.gov (United States)

Piai, Vitória; Vos, Sandra H; Idelberger, Reinhard; Gans, Pauline; Doorduin, Jonne; Ter Laan, Mark

2018-02-27

We report the case of a professional violin player who underwent an awake craniotomy to resect a tumor in the left supplementary motor area, an area involved in motor planning. A careful pre- and intraoperative monitoring plan for music performance and complex motor function was established that could be used in combination with cortical stimulation. The patient suffered an epileptic seizure during cortical stimulation. The monitoring of complex motor and musical functions was implemented with the patient playing the violin while the resection was performed. Almost complete resection was achieved with no notable postoperative deficits contributing to functional impairment. The multidisciplinary approach, involving neurosurgery, neuropsychology, anesthesiology, and clinical neurophysiology, allowed us to successfully cope with the theoretical and practical challenges associated with tailored care for a professional musician. The music and motor monitoring plan is reported in detail to enable other sites to reproduce and adapt it accordingly.

Neuronal Substrates Underlying Performance Variability in Well-Trained Skillful Motor Task in Humans.

Science.gov (United States)

Mizuguchi, Nobuaki; Uehara, Shintaro; Hirose, Satoshi; Yamamoto, Shinji; Naito, Eiichi

2016-01-01

Motor performance fluctuates trial by trial even in a well-trained motor skill. Here we show neural substrates underlying such behavioral fluctuation in humans. We first scanned brain activity with functional magnetic resonance imaging while healthy participants repeatedly performed a 10 s skillful sequential finger-tapping task. Before starting the experiment, the participants had completed intensive training. We evaluated task performance per trial (number of correct sequences in 10 s) and depicted brain regions where the activity changes in association with the fluctuation of the task performance across trials. We found that the activity in a broader range of frontoparietocerebellar network, including the bilateral dorsolateral prefrontal cortex (DLPFC), anterior cingulate and anterior insular cortices, and left cerebellar hemisphere, was negatively correlated with the task performance. We further showed in another transcranial direct current stimulation (tDCS) experiment that task performance deteriorated, when we applied anodal tDCS to the right DLPFC. These results indicate that fluctuation of brain activity in the nonmotor frontoparietocerebellar network may underlie trial-by-trial performance variability even in a well-trained motor skill, and its neuromodulation with tDCS may affect the task performance.

The fourth dimension: A motoric perspective on the anxiety–performance relationship

Science.gov (United States)

Carson, Howie J.; Collins, Dave

2016-01-01

ABSTRACT This article focuses on raising concern that anxiety–performance relationship theory has insufficiently catered for motoric issues during, primarily, closed and self-paced skill execution (e.g., long jump and javelin throw). Following a review of current theory, we address the under-consideration of motoric issues by extending the three-dimensional model put forward by Cheng, Hardy, and Markland (2009) (‘Toward a three-dimensional conceptualization of performance anxiety: Rationale and initial measurement development, Psychology of Sport and Exercise, 10, 271–278). This fourth dimension, termed skill establishment, comprises the level and consistency of movement automaticity together with a performer's confidence in this specific process, as providing a degree of robustness against negative anxiety effects. To exemplify this motoric influence, we then offer insight regarding current theories’ misrepresentation that a self-focus of attention toward an already well-learned skill always leads to a negative performance effect. In doing so, we draw upon applied literature to distinguish between positive and negative self-foci and suggest that on what and how a performer directs their attention is crucial to the interaction with skill establishment and, therefore, performance. Finally, implications for skill acquisition research are provided. Accordingly, we suggest a positive potential flow from applied/translational to fundamental/theory-generating research in sport which can serve to freshen and usefully redirect investigation into this long-considered but still insufficiently understood concept. PMID:26692896

Motor Performance as Predictor of Physical Activity in Children: The CHAMPS Study-DK.

Science.gov (United States)

Larsen, Lisbeth Runge; Kristensen, Peter Lund; Junge, Tina; Rexen, Christina Trifonov; Wedderkopp, Niels

2015-09-01

Physical activity (PA) is associated with several health benefits in children, and PA habits developed in childhood tend to persist into adulthood. PA may be the foundation of a healthy lifestyle, and motor performance has been shown to be positively associated with PA in cross-sectional studies. The purpose of this study was to explore the longitudinal relation between motor performance and PA in a 3-yr follow-up study. Longitudinal analyses were performed using data from 673 participants (44% boys, 6-12 yr old) who had been included in the Childhood Health Activity and Motor Performance School study-DK. Baseline motor performance tests consisted of vertical jump, shuttle run, hand grip strength, backward balance, precision throw, and cardiovascular fitness. Composite z-scores were generated to express health-related fitness and performance-related fitness. PA was measured by accelerometer at baseline and at 3-yr follow-up and was expressed as a percentage of time in moderate-to-vigorous PA. Cardiovascular fitness, vertical jump, health-related fitness, and performance-related fitness showed significant positive associations with 3-yr follow-up measures of PA in both sexes. Furthermore, shuttle run showed significant inverse associations with follow-up measures of PA for both sexes. Cardiorespiratory fitness, shuttle run, vertical jump, health-related fitness, and performance-related fitness were significantly associated with time spent in moderate-to-vigorous PA at 3-yr follow-up. The clinical relevance of the results indicates that cardiorespiratory fitness and shuttle run in childhood may be important determinants of PA in adolescence.

An electrical gearbox by means of pole variation for induction and superconducting disc motor

International Nuclear Information System (INIS)

Inacio, S; Inacio, D; Pina, J M; Valtchev, S; Neves, M V; Rodrigues, A L

2008-01-01

In this paper, a poly-phase disc motor innovative feeding and control strategy, based on a variable poles approach, and its application to a HTS disc motor, are presented. The stator windings may be electronically commutated to implement a 2, 4, 6 or 8 poles winding, thus changing the motor's torque/speed characteristics. The motor may be a conventional induction motor with a conductive disc rotor, or a new HTS disc motor, with conventional copper windings at its two iron semi-stators, and a HTS disc as a rotor. The conventional induction motor's operation principle is related with the induced electromotive forces in the conductive rotor. Its behaviour, characteristics (namely their torque/speed characteristics for different number of pole pairs) and modelling through Steinmetz and others theories are well known. The operation principle of the motor with HTS rotor, however, is rather different and is related with vortices' dynamics and pinning characteristics; this is a much more complex process than induction, and its modelling is quite complicated. In this paper, the operation was simulated through finite-elements commercial software, whereas superconductivity was simulated by the E-J power law. The Electromechanical performances of both motors where computed and are presented and compared. Considerations about the systems overall efficiency, including cryogenics, are also discussed

Trends in Motor Performance of First Graders: A Comparison of Cohorts from 2006 to 2015.

Science.gov (United States)

Spengler, Sarah; Rabel, Matthias; Kuritz, Arvid Marius; Mess, Filip

2017-01-01

Motor performance is an important factor for health. Already in childhood, motor performance is associated with, e.g., obesity and risk factors for cardiovascular diseases. It is widely believed that the motor performance of children has declined over recent years. However, this belief is lacking clear evidence. The objective of this study was to examine trends in motor performance of first grade students during a period of 10 years (2006-2015). We examined trends in (a) aerobic fitness, (b) strength, (c) speed, and (d) balance for boys and girls separately and considered body mass index (BMI) as a potential confounder. From 2006 to 2015, we tested 5,001 first graders [50.8% boys; mean age 6.76 (0.56) years] of 18 primary schools in Germany. Each year between 441 and 552 students of the same schools were surveyed. Performance tests were taken from the Motorik-Module Study and the "German Motor Ability Test": "6-min run," "push-ups," "20-m sprint," and "static stand." Linear regression models were conducted for statistical analysis. A slightly negative trend in aerobic fitness performance was revealed in boys (β = -0.050; p  = 0.012) but not in girls. In the strength performance test no trend over time was detected. Performance in speed (boys: β = -0.094; girls: β = -0.143; p  ≤ 0.001) and balance tests (boys: β = -0.142; girls: β = -0.232; p  ≤ 0.001) increased over time for both boys and girls. These findings held true when BMI was considered. This study only partly supported the assumption that motor performance of children has declined: in our study, aerobic fitness declined (only in boys), while strength remained stable and speed and balance even increased in both sexes. Moreover, it seems as if BMI can explain changes in performance only to a small extent. Changed lifestyles might be a substantial cause. Further research on recent trends of motor performance and interacting variables is needed to support the results

Improving motor reliability in nuclear power plants: Volume 1, Performance evaluation and maintenance practices

International Nuclear Information System (INIS)

Subudhi, M.; Gunther, W.E.; Taylor, J.H.; Sugarman, A.C.; Sheets, M.W.

1987-11-01

This report constitutes the first of the three volumes under this NUREG. The report presents recommendations for developing a cost-effective program for performance evaluation and maintenance of electric motors in nuclear power plants. These recommendations are based on current industry practices, available techniques for monitoring degradation in motor components, manufacturer's recommendations, operating experience, and results from two laboratory tests on aged motors. Two laboratory test reports on a small and a large motor are presented in separate volumes of this NUREG. These provide the basis for the various functional indicators recommended for maintenance programs in this report. The overall preventive maintenance program is separated into two broad areas of activity aimed at mitigating the potential effects of equipment aging: Performance Evaluation and Equipment Maintenance. The latter involves actually maintaining the condition of the equipment while the former involves those activities undertaken to monitor degradation due to aging. These monitoring methods are further categorized into periodic testing, surveillance testing, continuous monitoring and inspections. This study focuses on the methods and procedures for performing the above activities to maintain the motors operationally ready in a nuclear facility. This includes an assessment of various functional indicators to determine their suitability for trending to monitor motor component condition. The intrusiveness of test methods and the present state-of-the-art for using the test equipment in a plant environment are discussed. In conclusion, implementation of the information provided in this report, will improve motor reliability in nuclear power plants. The study indicates the kinds of tests to conduct, how and when to conduct them, and to which motors the tests should be applied. 44 refs., 12 figs., 13 tabs

Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance.

Science.gov (United States)

Molero-Chamizo, Andrés; Alameda Bailén, José R; Garrido Béjar, Tamara; García López, Macarena; Jaén Rodríguez, Inmaculada; Gutiérrez Lérida, Carolina; Pérez Panal, Silvia; González Ángel, Gloria; Lemus Corchero, Laura; Ruiz Vega, María J; Nitsche, Michael A; Rivera-Urbina, Guadalupe N

2018-02-01

Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS-namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

Cerebellar contribution to motor and cognitive performance in multiple sclerosis: An MRI sub-regional volumetric analysis.

Science.gov (United States)

D'Ambrosio, Alessandro; Pagani, Elisabetta; Riccitelli, Gianna C; Colombo, Bruno; Rodegher, Mariaemma; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo; Rocca, Maria A

2017-08-01

To investigate the role of cerebellar sub-regions on motor and cognitive performance in multiple sclerosis (MS) patients. Whole and sub-regional cerebellar volumes, brain volumes, T2 hyperintense lesion volumes (LV), and motor performance scores were obtained from 95 relapse-onset MS patients and 32 healthy controls (HC). MS patients also underwent an evaluation of working memory and processing speed functions. Cerebellar anterior and posterior lobes were segmented using the Spatially Unbiased Infratentorial Toolbox (SUIT) from Statistical Parametric Mapping (SPM12). Multivariate linear regression models assessed the relationship between magnetic resonance imaging (MRI) measures and motor/cognitive scores. Compared to HC, only secondary progressive multiple sclerosis (SPMS) patients had lower cerebellar volumes (total and posterior cerebellum). In MS patients, lower anterior cerebellar volume and brain T2 LV predicted worse motor performance, whereas lower posterior cerebellar volume and brain T2 LV predicted poor cognitive performance. Global measures of brain volume and infratentorial T2 LV were not selected by the final multivariate models. Cerebellar volumetric abnormalities are likely to play an important contribution to explain motor and cognitive performance in MS patients. Consistently with functional mapping studies, cerebellar posterior-inferior volume accounted for variance in cognitive measures, whereas anterior cerebellar volume accounted for variance in motor performance, supporting the assessment of cerebellar damage at sub-regional level.

An Allometric Modelling Approach to Identify the Optimal Body Shape Associated with, and Differences between Brazilian and Peruvian Youth Motor Performance.

Directory of Open Access Journals (Sweden)

Simonete Silva

Full Text Available Children from developed and developing countries differ in their body size and shape due to marked differences across their life history caused by social, economic and cultural differences which are also linked to their motor performance (MP. We used allometric models to identify size/shape characteristics associated with MP tests between Brazilian and Peruvian schoolchildren. A total of 4,560 subjects, 2,385 girls and 2,175 boys aged 9-15 years were studied. Height and weight were measured; biological maturation was estimated with the maturity offset technique; MP measures included the 12 minute run (12MR, handgrip strength (HG, standing long jump (SLJ and the shuttle run speed (SR tests; physical activity (PA was assessed using the Baecke questionnaire. A multiplicative allometric model was adopted to adjust for body size differences across countries. Reciprocal ponderal index (RPI was found to be the most suitable body shape indicator associated with the 12MR, SLJ, HG and SR performance. A positive maturation offset parameter was also associated with a better performance in SLJ, HG and SR tests. Sex differences were found in all motor tests. Brazilian youth showed better scores in MP than their Peruvian peers, even when controlling for their body size differences The current study identified the key body size associated with four body mass-dependent MP tests. Biological maturation and PA were associated with strength and motor performance. Sex differences were found in all motor tests, as well as across countries favoring Brazilian children even when accounting for their body size/shape differences.

An Allometric Modelling Approach to Identify the Optimal Body Shape Associated with, and Differences between Brazilian and Peruvian Youth Motor Performance.

Science.gov (United States)

Silva, Simonete; Bustamante, Alcibíades; Nevill, Alan; Katzmarzyk, Peter T; Freitas, Duarte; Prista, António; Maia, José

2016-01-01

Children from developed and developing countries differ in their body size and shape due to marked differences across their life history caused by social, economic and cultural differences which are also linked to their motor performance (MP). We used allometric models to identify size/shape characteristics associated with MP tests between Brazilian and Peruvian schoolchildren. A total of 4,560 subjects, 2,385 girls and 2,175 boys aged 9-15 years were studied. Height and weight were measured; biological maturation was estimated with the maturity offset technique; MP measures included the 12 minute run (12MR), handgrip strength (HG), standing long jump (SLJ) and the shuttle run speed (SR) tests; physical activity (PA) was assessed using the Baecke questionnaire. A multiplicative allometric model was adopted to adjust for body size differences across countries. Reciprocal ponderal index (RPI) was found to be the most suitable body shape indicator associated with the 12MR, SLJ, HG and SR performance. A positive maturation offset parameter was also associated with a better performance in SLJ, HG and SR tests. Sex differences were found in all motor tests. Brazilian youth showed better scores in MP than their Peruvian peers, even when controlling for their body size differences The current study identified the key body size associated with four body mass-dependent MP tests. Biological maturation and PA were associated with strength and motor performance. Sex differences were found in all motor tests, as well as across countries favoring Brazilian children even when accounting for their body size/shape differences.

An Allometric Modelling Approach to Identify the Optimal Body Shape Associated with, and Differences between Brazilian and Peruvian Youth Motor Performance

Science.gov (United States)

Silva, Simonete; Bustamante, Alcibíades; Nevill, Alan; Katzmarzyk, Peter T.; Freitas, Duarte; Prista, António; Maia, José

2016-01-01

Children from developed and developing countries differ in their body size and shape due to marked differences across their life history caused by social, economic and cultural differences which are also linked to their motor performance (MP). We used allometric models to identify size/shape characteristics associated with MP tests between Brazilian and Peruvian schoolchildren. A total of 4,560 subjects, 2,385 girls and 2,175 boys aged 9–15 years were studied. Height and weight were measured; biological maturation was estimated with the maturity offset technique; MP measures included the 12 minute run (12MR), handgrip strength (HG), standing long jump (SLJ) and the shuttle run speed (SR) tests; physical activity (PA) was assessed using the Baecke questionnaire. A multiplicative allometric model was adopted to adjust for body size differences across countries. Reciprocal ponderal index (RPI) was found to be the most suitable body shape indicator associated with the 12MR, SLJ, HG and SR performance. A positive maturation offset parameter was also associated with a better performance in SLJ, HG and SR tests. Sex differences were found in all motor tests. Brazilian youth showed better scores in MP than their Peruvian peers, even when controlling for their body size differences The current study identified the key body size associated with four body mass-dependent MP tests. Biological maturation and PA were associated with strength and motor performance. Sex differences were found in all motor tests, as well as across countries favoring Brazilian children even when accounting for their body size/shape differences. PMID:26939118

Influence of different rotor magnetic circuit structure on the performance of permanent magnet synchronous motor

Directory of Open Access Journals (Sweden)

Qiu Hongbo

2017-09-01

Full Text Available In order to compare the performance difference of the permanent magnet synchronous motors (PMSM with different rotor structure, two kinds of rotor magnetic circuit structure with surface-mounted radial excitation and tangential excitation are designed respectively. By comparing and analyzing the results, the difference of the motor performance was determined. Firstly, based on the finite element method (FEM, the motor electromagnetic field performance was studied, and the magnetic field distribution of the different magnetic circuit structure was obtained. The influence mechanism of the different magnetic circuit structure on the air gap flux density was obtained by using the Fourier theory. Secondly, the cogging torque, output torque and overload capacity of the PMSM with different rotor structure were studied. The effect mechanism of the different rotor structure on the motor output property difference was obtained. The motor prototype with two kinds of rotor structure was manufactured, and the experimental study was carried out. By comparing the experimental data and simulation data, the correctness of the research is verified. This paper lays a foundation for the research on the performance of the PMSM with different magnetic circuit structure.

Characteristic analysis of a traveling wave ultrasonic motor using an ellipsoidal static contact model

International Nuclear Information System (INIS)

Lim, Jung Pil; Rho, Jong Seok; Yi, Kyung Pyo; Jung, Hyun Kyo; Seo, Jung Moo

2009-01-01

A characteristic analysis of an ultrasonic motor (USM) at the design stage has thus far been impossible. Therefore, a characteristic analysis method is suggested on the basis of a proposed model describing the complex nonlinear contact condition between the rotor and stator. The proposed contact model and analysis method can guide theoretical research on the minimization of the main disadvantages of the USM, which mainly result from the contact mechanism. The validity and usefulness of the suggested analysis method is verified by experimental data from a prototyped USM

The effect of caffeine on cognitive task performance and motor fatigue

NARCIS (Netherlands)

van Duinen, Hiske; Lorist, Monicque M.; Zijdewind, Inge

Rationale: In everyday life, people are usually capable of performing two tasks simultaneously. However, in a previous study we showed that during a fatiguing motor task, cognitive performance declined progressively. There is extensive literature on the ( positive) effects of caffeine on cognitive

Passing thoughts on the evolutionary stability of implicit motor behaviour: performance retention under physiological fatigue.

Science.gov (United States)

Poolton, J M; Masters, R S W; Maxwell, J P

2007-06-01

Heuristics of evolutionary biology (e.g., survival of the fittest) dictate that phylogenetically older processes are inherently more stable and resilient to disruption than younger processes. On the grounds that non-declarative behaviour emerged long before declarative behaviour, Reber (1992) argues that implicit (non-declarative) learning is supported by neural processes that are evolutionarily older than those supporting explicit learning. Reber suggested that implicit learning thus leads to performance that is more robust than explicit learning. Applying this evolutionary framework to motor performance, we examined whether implicit motor learning, relative to explicit motor learning, conferred motor output that was resilient to physiological fatigue and durable over time. In Part One of the study a fatigued state was induced by a double Wingate Anaerobic test protocol. Fatigue had no affect on performance of participants in the implicit condition; whereas, performance of participants in the explicit condition deteriorated significantly. In Part Two of the study a convenience sample of participants was recalled following a one-year hiatus. In both the implicit and the explicit condition retention of performance was seen and, contrary to the findings in Part One, so was resilience to fatigue. The resilient performance in the explicit condition after one year may have resulted from forgetting (the decay of declarative knowledge) or from consolidation of declarative knowledge as implicit memories. In either case, implicit processes were left to more effectively support motor performance.

Motor performance of preschool children

OpenAIRE

Karina Słonka; Manuela Dyas; Tadeusz Słonka; Tomasz Szurmik

2017-01-01

Introduction: Pre‑school age is a period of intensive development when children shape their posture, habits and motor memory. Movement is child's physiological need.  Motive activity supports not only physical development, but also psychical, intellectual and social.   Aim: The aim of the study is to assess motor ability in preschool children from the city of Opole and District Dobrzeń Wielki. Materials and methods: The research involved 228 children, aged 5 and 6. The method used in...

Over-focused? The relation between patients' inclination for conscious control and single- and dual-task motor performance after stroke.

Science.gov (United States)

Denneman, R P M; Kal, E C; Houdijk, H; Kamp, J van der

2018-05-01

Many stroke patients are inclined to consciously control their movements. This is thought to negatively affect patients' motor performance, as it disrupts movement automaticity. However, it has also been argued that conscious control may sometimes benefit motor performance, depending on the task or patientś motor or cognitive capacity. To assess whether stroke patients' inclination for conscious control is associated with motor performance, and explore whether the putative association differs as a function of task (single- vs dual) or patientś motor and cognitive capacity. Univariate and multivariate linear regression analysis were used to assess associations between patients' disposition to conscious control (i.e., Conscious Motor Processing subscale of Movement-Specific Reinvestment Scale; MSRS-CMP) and single-task (Timed-up-and-go test; TuG) and motor dual-task costs (TuG while tone counting; motor DTC%). We determined whether these associations were influenced by patients' walking speed (i.e., 10-m-walk test) and cognitive capacity (i.e., working memory, attention, executive function). Seventy-eight clinical stroke patients (task TuG performance. However, patients with a strong inclination for conscious control showed higher motor DTC%. These associations were irrespective of patients' motor and cognitive abilities. Patients' disposition for conscious control was not associated with single task motor performance, but was associated with higher motor dual task costs, regardless of patients' motor or cognitive abilities. Therapists should be aware that patients' conscious control inclination can influence their dual-task performance while moving. Longitudinal studies are required to test whether reducing patients' disposition for conscious control would improve dual-tasking post-stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

Toxicological and performance aspects of oxygenated motor vehicle fuels

National Research Council Canada - National Science Library

National Research Council Staff; Commission on Life Sciences; Division on Earth and Life Studies; National Research Council; National Academy of Sciences

... COMMITTEE ON TOXICOLOGICAL PERFORMANCE ASPECTS OXYGENATED MOTOR VEHICLE FUELS ENVIRONMENTAL STUDIES TOXICOLOGY COMMISSION LIFE SCIENCES NATIONAL RESEARCH COUNCIL AND OF BOARD ON AND ON NATIONAL ACADEMY PRESS Washington, D.C. 1996 i Copyrightoriginal retained, the be not from cannot book, paper original however, for version formatting, authoritative the t...

Performance characteristics of conventional X-ray generator isotope source and high energy accelerator in rocket motor evaluation

International Nuclear Information System (INIS)

Viswanathan, K.; Rao, K.V.; Subbalah, C.; Uttam, M.C.

1985-01-01

Final qualification of solid rocket motors and other related components in the Indian Space Programme is carried out using radiographic sources of different energies. The necessity to have different sources of varying energies arises from the fact that the components in the space programme vary from small fastners to gigantic solid rocket motors. In order to achieve the best radiographic quality with the optimised exposure time different X-ray sources are used. To have 100% coverage and to reduce the inspection time, a Real Time Radiography for the high energy LINAC is also planned

Learning trajectories for speech motor performance in children with specific language impairment.

Science.gov (United States)

Richtsmeier, Peter T; Goffman, Lisa

2015-01-01

Children with specific language impairment (SLI) often perform below expected levels, including on tests of motor skill and in learning tasks, particularly procedural learning. In this experiment we examined the possibility that children with SLI might also have a motor learning deficit. Twelve children with SLI and thirteen children with typical development (TD) produced complex nonwords in an imitation task. Productions were collected across three blocks, with the first and second blocks on the same day and the third block one week later. Children's lip movements while producing the nonwords were recorded using an Optotrak camera system. Movements were then analyzed for production duration and stability. Movement analyses indicated that both groups of children produced shorter productions in later blocks (corroborated by an acoustic analysis), and the rate of change was comparable for the TD and SLI groups. A nonsignificant trend for more stable productions was also observed in both groups. SLI is regularly accompanied by a motor deficit, and this study does not dispute that. However, children with SLI learned to make more efficient productions at a rate similar to their peers with TD, revealing some modification of the motor deficit associated with SLI. The reader will learn about deficits commonly associated with specific language impairment (SLI) that often occur alongside the hallmark language deficit. The authors present an experiment showing that children with SLI improved speech motor performance at a similar rate compared to typically developing children. The implication is that speech motor learning is not impaired in children with SLI. Copyright © 2015 Elsevier Inc. All rights reserved.

Control and Performance Evaluation of Multiphase FSPM Motor in Low-Speed Region for Hybrid Electric Vehicles

Directory of Open Access Journals (Sweden)

Feng Yu

2015-09-01

Full Text Available The flux-switching permanent-magnet (FSPM motor has been viewed as a highly reliable machine with both armature windings and magnets on the stator. Owing to the high torque-production capability with low torque ripple, FSPM motors with a higher number of phases are potential candidates for traction applications in hybrid electric vehicles (HEVs. However, existing research has mostly focused on the principles and static performance of multiphase FSPM motors, and little attention has been paid to advanced control strategies. In this paper, the fully decoupled current control of a 36/34-pole nine-phase FSPM (NP-FSPM motor is developed and the performance under different operating conditions is investigated. The aim of the design is to alleviate cross coupling effects and unwanted low-order stator harmonic currents, to guarantee fast transient response and small steady-state error. In addition, its fault-tolerance is further elaborated. These features are very important in automotive applications where low torque pulsation, high fault-tolerant capability and high dynamic performance are of major importance. Firstly, the research status of multiphase FSPM motors is briefly reviewed. Secondly, the mathematical model in the dq reference frames and control strategies are presented. Then, the control and performance of the NP-FSPM motor are evaluated by using MATLAB/Simulink. Finally, experiments on an NP-FSPM motor prototype are carried out to validate the study.

AC Application of HTS Conductors in Highly Dynamic Electric Motors

International Nuclear Information System (INIS)

Oswald, B; Best, K-J; Setzer, M; Duffner, E; Soell, M; Gawalek, W; Kovalev, L K

2006-01-01

Based on recent investigations we design highly dynamic electric motors up to 400 kW and linear motors up to 120 kN linear force using HTS bulk material and HTS tapes. The introduction of HTS tapes into AC applications in electric motors needs fundamental studies on double pancake coils under transversal magnetic fields. First theoretical and experimental results on AC field distributions in double-pancake-coils and corresponding AC losses will be presented. Based on these results the simulation of the motor performance confirms extremely high power density and efficiency of both types of electric motors. Improved characteristics of rare earth permanent magnets used in our motors at low temperatures give an additional technological benefit

Self-Concept in Adolescents—Relationship between Sport Participation, Motor Performance and Personality Traits

OpenAIRE

Markus Klein; Michael Fröhlich; Eike Emrich

2017-01-01

The relationship between sport participation, personality development, self-concept and self-esteem has been discussed repeatedly. In this research, a standardized written survey together with tests on motor performance were carried out with 1399 students (707 male; 692 female) in school years 7 (12.9 ± 0.6 years) and 10 (15.8 ± 0.6 years) to measure the extent of a relationship between physical self-concept (self-developed short scale) and sporting activity, measured motor performance (Germa...

Motor development in individuals with congenital adrenal hyperplasia: strength, targeting, and fine motor skill.

Science.gov (United States)

Collaer, Marcia L; Brook, Charles G D; Conway, Gerard S; Hindmarsh, Peter C; Hines, Melissa

2009-02-01

This study investigated early androgen influence on the development of human motor and visuomotor characteristics. Participants, ages 12-45 years, were individuals with congenital adrenal hyperplasia (CAH), a disorder causing increased adrenal androgen production before birth (40 females, 29 males) and their unaffected relatives (29 females, 30 males). We investigated grip strength and visuomotor targeting tasks on which males generally outperform females, and fine motor pegboard tasks on which females generally outperform males. Physical characteristics (height and weight) were measured to explore whether body parameters could explain differences in motor skills. Females with CAH were stronger and showed better targeting than unaffected females and showed reduced fine visuomotor skill on one pegboard measure, with no difference on the other. Males with CAH were weaker than unaffected males in grip strength but did not differ on the targeting or pegboard measures. Correction for body size could not explain the findings for females, but suggests that the reduced strength of males with CAH may relate to their smaller stature. Further, the targeting advantage in females with CAH persisted following adjustment for their greater strength. Results in females support the hypothesis that androgen may masculinize, or promote, certain motor characteristics at which males excel, and contribute to defeminization of certain fine motor characteristics at which females excel. Thus, these data suggest that organizational effects of androgens on behavior during prenatal life may extend to motor characteristics and may contribute to general sex differences in motor-related behaviors; however, alternative explanations based on activational influences of androgen or altered experiential factors cannot be excluded without further study.

Individual Differences Influencing Immediate Effects of Internal and External Focus Instructions on Children's Motor Performance.

Science.gov (United States)

van Abswoude, Femke; Nuijen, Nienke B; van der Kamp, John; Steenbergen, Bert

2018-06-01

A large pool of evidence supports the beneficial effect of an external focus of attention on motor skill performance in adults. In children, this effect has been studied less and results are inconclusive. Importantly, individual differences are often not taken into account. We investigated the role of working memory, conscious motor control, and task-specific focus preferences on performance with an internal and external focus of attention in children. Twenty-five children practiced a golf putting task in both an internal focus condition and external focus condition. Performance was defined as the average distance toward the hole in 3 blocks of 10 trials. Task-specific focus preference was determined by asking how much effort it took to apply the instruction in each condition. In addition, working memory capacity and conscious motor control were assessed. Children improved performance in both the internal focus condition and external focus condition (ŋ p 2  = .47), with no difference between conditions (ŋ p 2  = .01). Task-specific focus preference was the only factor moderately related to the difference between performance with an internal focus and performance with an external focus (r = .56), indicating better performance for the preferred instruction in Block 3. Children can benefit from instruction with both an internal and external focus of attention to improve short-term motor performance. Individual, task-specific focus preference influenced the effect of the instructions, with children performing better with their preferred focus. The results highlight that individual differences are a key factor in the effectiveness in children's motor performance. The precise mechanisms underpinning this effect warrant further research.

Self-Concept in Adolescents—Relationship between Sport Participation, Motor Performance and Personality Traits

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Markus Klein

2017-04-01

Full Text Available The relationship between sport participation, personality development, self-concept and self-esteem has been discussed repeatedly. In this research, a standardized written survey together with tests on motor performance were carried out with 1399 students (707 male; 692 female in school years 7 (12.9 ± 0.6 years and 10 (15.8 ± 0.6 years to measure the extent of a relationship between physical self-concept (self-developed short scale and sporting activity, measured motor performance (German motor performance test DMT (Deutscher Motorik-Test 6–18 and report mark in physical education. Relationships were also analyzed between physical self-concept and general personality traits (neuroticism, extraversion, openness to experiences, compatibility, and conscientiousness, measured with NEO Five Factor Inventory (NEO-FFI. The assessment of own physical attractiveness and own athleticism differs by sex (F(1, 962 = 35.21; p < 0.001, whereby girls assess themselves more critically. Weak significant relationships are displayed between motor performance and the assessment of own physical attractiveness (r(395 = 0.31; p < 0.01. Motor performance is given a higher predictive value with regard to a subject’s own self-concept, (physical attractiveness β = 0.37; t(249 = 5.24; p < 0.001; athleticism β = 0.40; t(248 = 6.81; p < 0.001 than the mark achieved in physical education (physical attractiveness β = −0.01; n.s.; athleticism β = −0.30; t(248 = 5.10; p < 0.001. Relationships were found overall between personality traits and physical self-concept. The influence of the ‘neuroticism’ trait is particularly strong (physical attractiveness β = −0.44; t(947 = −13.58; p < 0.001; athleticism β = −0.27; t(948 = −7.84; p < 0.001. The more pronounced this trait, the lower the assessment of own physical attractiveness and own athleticism.

Anthropometric characteristics, physical fitness and motor coordination of 9 to 11 year old children participating in a wide range of sports.

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Opstoel, Katrijn; Pion, Johan; Elferink-Gemser, Marije; Hartman, Esther; Willemse, Bas; Philippaerts, Renaat; Visscher, Chris; Lenoir, Matthieu

2015-01-01

The aim of this study was to investigate to what extent 9 to 11 year old children participating in a specific sport already exhibit a specific anthropometric, physical fitness and motor coordination profile, in line with the requirements of that particular sport. In addition, the profiles in children with a different training volume were compared and possible differences in training hours per week between children from a low, moderate, and high level of physical fitness and motor coordination were investigated. Data of 620 children, 347 boys and 273 girls, who participated in the Flemish Sports Compass were used. Only the primary sport of each child was considered and six groups of sports (Ball sports, Dance, Gymnastics, Martial arts, Racquet sports and Swimming) were formed based on common characteristics. Measurements consisted of 17 tests. Independent T-tests and Mann-Whitney U-tests revealed few differences between the groups of sports and the discriminant analyses with the moderate and low active group did not show any significant results (p > .05). However, when discriminating among the high active children, a 85.2 % correct classification between six groups of sports was found (Wilks' Λ = .137 and p sport per week (2.50 ± 1.84 hours) compared to the children performing best (3.25 ± 2.60 hours) (p = .016) and the children performing above average (2.90 ± 1.96 hours) (p = .029) on physical fitness and motor coordination. The study showed that in general, children at a young age do not exhibit sport-specific characteristics, except in children with a high training volume. It is possible that on the one hand, children have not spent enough time yet in their sport to develop sport-specific qualities. On the other hand, it could be possible that they do not take individual qualities into account when choosing a sport.

Smooth torque speed characteristic of switched reluctance motors

DEFF Research Database (Denmark)

Zeng, Hui; Chen, Zhe; Chen, Hao

2014-01-01

The torque ripple of switched reluctance motors (SRMs) is the main disadvantage that limits the industrial application of these motors. Although several methods for smooth-toque operation (STO) have been proposed, STO works well only within a certain torque and speed range because...

Trauma history characteristics and subsequent PTSD symptoms in motor vehicle accident victims.

Science.gov (United States)

Irish, Leah; Ostrowski, Sarah A; Fallon, William; Spoonster, Eileen; Dulmen, Manfred van; Sledjeski, Eve M; Delahanty, Douglas L

2008-08-01

The present study examined the relationship between trauma history characteristics (number and type of traumas, age at first trauma, and subjective responses to prior traumas) and the development of posttraumatic stress disorder (PTSD) symptoms following a motor vehicle accident (MVA). One hundred eighty-eight adult MVA victims provided information about prior traumatization and were evaluated for PTSD symptoms 6 weeks and one year following the MVA. Results indicated that after controlling for demographics and depression, prior trauma history characteristics accounted for a small, but significant amount of the variance in PTSD symptoms. Distress from prior trauma and number of types of prior traumas were the most meaningful trauma history predictors. Results encourage further evaluation of trauma history as a multifaceted construct.

Comparing motor performance, praxis, coordination, and interpersonal synchrony between children with and without Autism Spectrum Disorder (ASD).

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Kaur, Maninderjit; M Srinivasan, Sudha; N Bhat, Anjana

2018-01-01

Children with Autism Spectrum Disorder (ASD) have basic motor impairments in balance, gait, and coordination as well as autism-specific impairments in praxis/motor planning and interpersonal synchrony. Majority of the current literature focuses on isolated motor behaviors or domains. Additionally, the relationship between cognition, symptom severity, and motor performance in ASD is unclear. We used a comprehensive set of measures to compare gross and fine motor, praxis/imitation, motor coordination, and interpersonal synchrony skills across three groups of children between 5 and 12 years of age: children with ASD with high IQ (HASD), children with ASD with low IQ (LASD), and typically developing (TD) children. We used the Bruininks-Oseretsky Test of Motor Proficiency and the Bilateral Motor Coordination subtest of the Sensory Integration and Praxis Tests to assess motor performance and praxis skills respectively. Children were also examined while performing simple and complex rhythmic upper and lower limb actions on their own (solo context) and with a social partner (social context). Both ASD groups had lower gross and fine motor scores, greater praxis errors in total and within various error types, lower movement rates, greater movement variability, and weaker interpersonal synchrony compared to the TD group. In addition, the LASD group had lower gross motor scores and greater mirroring errors compared to the HASD group. Overall, a variety of motor impairments are present across the entire spectrum of children with ASD, regardless of their IQ scores. Both, fine and gross motor performance significantly correlated with IQ but not with autism severity; however, praxis errors (mainly, total, overflow, and rhythmicity) strongly correlated with autism severity and not IQ. Our study findings highlight the need for clinicians and therapists to include motor evaluations and interventions in the standard-of-care of children with ASD and for the broader autism community to

Motor current signature analysis for determining operational readiness of motor-operated valves (MOVs)

International Nuclear Information System (INIS)

Kryter, R.C.; Haynes, H.D.

1987-01-01

Motor current signature analysis (MCSA) is a novel diagnostic process for condition monitoring of electric-motor-driven mechanical equipment (e.g., pumps, motor-operated valves, compressors, and processing machinery). The MCSA process identifies, characterizes, and trends over time the instantaneous load variations of mechanical equipment in order to diagnose changes in the condition of the equipment (e.g., due to degradation or service wear), which, if allowed to continue, may lead to failure. It monitors the instantaneous variations (noise content) in the electric current flowing through the power leads to the electric motor that drives the equipment. The motor itself thereby acts as a transducer, sensing both large and small, long-term and rapid, mechanical load variations and converting them to variations in the induced current generated in the motor windings. This motor current noise signature is detected, amplified, and further processed as needed to examine its time domain and frequency domain (spectral) characteristics. The operational principles of MCSA and the nonintrusive data collection apparatus and procedure used with MOVs will be described. Data collected from MOVs in both laboratory and in-plant environments will also be shown to illustrate the ability of MCSA to ''see'' the detailed inner workings of the valve and operator and thus to detect degraded performance at an incipient stage. (Set of 18 vugraphs)

Effects of 6 weeks motor-enrichment-intervention to improve math performance in preadolescent children

DEFF Research Database (Denmark)

Wienecke, Jacob; Beck, Mikkel Malling; Lind, Rune Rasmussen

al., 2015). We conducted a six-week cluster-randomized intervention study of motor-enriched mathematics for Danish schoolchildren (n= 148, age= 7.5 ± 0.02). We investigated whether low intensity motor activity congruently integrated during solving of math problems could enhance math performance....... Three groups were included: 1) Control group with normal math teaching, CON (used pencil, paper but refrained from additional motor activity). 2) Fine-motor-enriched-group, FM (motor-manipulating LEGO bricks integrated in the lessons). 3) Gross-motor-enriched-group, GM (full-body movements integrated...... in the lessons). In FM and GM, all math classes (six lessons pr. week) had motor activity integrated in the math lessons and the teachers of all groups followed a detailed description for the conduction of the lessons. This aimed at ensuring homogeneity between groups concerning the taught themes. The children...

On-line PWR RHR pump performance testing following motor and impeller replacement

International Nuclear Information System (INIS)

DiMarzo, J.T.

1996-01-01

On-line maintenance and replacement of safety-related pumps requires the performance of an inservice test to determine and confirm the operational readiness of the pumps. In 1995, major maintenance was performed on two Pressurized Water Reactor (PWR) Residual Heat Removal (RHR) Pumps. A refurbished spare motor was overhauled with a new mechanical seal, new motor bearings and equipped with pump's 'B' impeller. The spare was installed into the 'B' train. The motor had never been run in the system before. A pump performance test was developed to verify it's operational readiness and determine the in-situ pump performance curve. Since the unit was operating, emphasis was placed on conducting a highly accurate pump performance test that would ensure that it satisfied the NSSS vendors accident analysis minimum acceptance curve. The design of the RHR System allowed testing of one train while the other was aligned for normal operation. A test flow path was established from the Refueling Water Storage Tank (RWST) through the pump (under test) and back to the RWST. This allowed staff to conduct a full flow range pump performance test. Each train was analyzed and an expression developed that included an error vector term for the TDH (ft), pressure (psig), and flow rate (gpm) using the variance error vector methodology. This method allowed the engineers to select a test instrumentation system that would yield accurate readings and minimal measurement errors, for data taken in the measurement of TDH (P,Q) versus Pump Flow Rate (Q). Test results for the 'B' Train showed performance well in excess of the minimum required. The motor that was originally in the 'B' train was similarly overhauled and equipped with 'A' pump's original impeller, re-installed in the 'A' train, and tested. Analysis of the 'A' train results indicate that the RHR pump's performance was also well in excess of the vendors requirements

On-line PWR RHR pump performance testing following motor and impeller replacement

Energy Technology Data Exchange (ETDEWEB)

DiMarzo, J.T.

1996-12-01

On-line maintenance and replacement of safety-related pumps requires the performance of an inservice test to determine and confirm the operational readiness of the pumps. In 1995, major maintenance was performed on two Pressurized Water Reactor (PWR) Residual Heat Removal (RHR) Pumps. A refurbished spare motor was overhauled with a new mechanical seal, new motor bearings and equipped with pump`s `B` impeller. The spare was installed into the `B` train. The motor had never been run in the system before. A pump performance test was developed to verify it`s operational readiness and determine the in-situ pump performance curve. Since the unit was operating, emphasis was placed on conducting a highly accurate pump performance test that would ensure that it satisfied the NSSS vendors accident analysis minimum acceptance curve. The design of the RHR System allowed testing of one train while the other was aligned for normal operation. A test flow path was established from the Refueling Water Storage Tank (RWST) through the pump (under test) and back to the RWST. This allowed staff to conduct a full flow range pump performance test. Each train was analyzed and an expression developed that included an error vector term for the TDH (ft), pressure (psig), and flow rate (gpm) using the variance error vector methodology. This method allowed the engineers to select a test instrumentation system that would yield accurate readings and minimal measurement errors, for data taken in the measurement of TDH (P,Q) versus Pump Flow Rate (Q). Test results for the `B` Train showed performance well in excess of the minimum required. The motor that was originally in the `B` train was similarly overhauled and equipped with `A` pump`s original impeller, re-installed in the `A` train, and tested. Analysis of the `A` train results indicate that the RHR pump`s performance was also well in excess of the vendors requirements.

Age-specific neural strategies to maintain motor performance after an acute social stress bout.

Science.gov (United States)

Mehta, Ranjana K; Rhee, Joohyun

2017-07-01

Stress due to cognitive demands and fatigue have shown to impair motor performance in older adults; however, the effect of social stress and its influence on prefrontal cortex (PFC) functioning in older adults during upper extremity motor performance tasks is not known. The present study explored the after-effects of an acute social stress bout on neural strategies, measured using PFC and hand/arm muscle activation, and adopted by younger and older adults to maintain handgrip force control. Nine older [74.1 (6.5) years; three men, six women] and ten younger [24.2 (5.0) years, four men, six women] adults performed handgrip force control trials at 30% maximum voluntary contractions before and after the Trier Social Stress Test (TSST). PFC activity was measured using functional near infrared spectroscopy and muscle activity from the flexor and extensor carpi radialis (FCR/ECR) was measured using electromyography. In general, aging was associated with decreased force steadiness and force complexity with a concomitant increase in bilateral PFC activity. While motor performance remained comparable before and after the TSST stress session in both age groups, the associated neural strategies differed between groups. While the stress condition was associated with lower FCR and ECR activity in younger adults despite no change in the PFC activation, stress was associated with increases in FCR activity in older adults. This stress-related compensatory neural strategy of increasing hand/arm muscle activation, potentially via the additional recruitment of the stress-motor neural circuitry, may have played a role in maintaining motor performance in older adults.

Trends in Motor Performance of First Graders: A Comparison of Cohorts from 2006 to 2015

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Sarah Spengler

2017-09-01

Full Text Available BackgroundMotor performance is an important factor for health. Already in childhood, motor performance is associated with, e.g., obesity and risk factors for cardiovascular diseases. It is widely believed that the motor performance of children has declined over recent years. However, this belief is lacking clear evidence. The objective of this study was to examine trends in motor performance of first grade students during a period of 10 years (2006–2015. We examined trends in (a aerobic fitness, (b strength, (c speed, and (d balance for boys and girls separately and considered body mass index (BMI as a potential confounder.MethodsFrom 2006 to 2015, we tested 5,001 first graders [50.8% boys; mean age 6.76 (0.56 years] of 18 primary schools in Germany. Each year between 441 and 552 students of the same schools were surveyed. Performance tests were taken from the Motorik-Module Study and the “German Motor Ability Test”: “6-min run,” “push-ups,” “20-m sprint,” and “static stand.” Linear regression models were conducted for statistical analysis.ResultsA slightly negative trend in aerobic fitness performance was revealed in boys (β = −0.050; p = 0.012 but not in girls. In the strength performance test no trend over time was detected. Performance in speed (boys: β = −0.094; girls: β = −0.143; p ≤ 0.001 and balance tests (boys: β = −0.142; girls: β = −0.232; p ≤ 0.001 increased over time for both boys and girls. These findings held true when BMI was considered.ConclusionThis study only partly supported the assumption that motor performance of children has declined: in our study, aerobic fitness declined (only in boys, while strength remained stable and speed and balance even increased in both sexes. Moreover, it seems as if BMI can explain changes in performance only to a small extent. Changed lifestyles might be a substantial cause. Further research on recent trends of motor

A Novel Single Phase Hybrid Switched Reluctance Motor Drive System

DEFF Research Database (Denmark)

Liang, Jianing; Xu, Guoqing; Jian, Linni

2011-01-01

In this paper, a novel single phase hybrid switched reluctance motor(SRM) drive system is proposed. It integrated a single phase hybrid SRM and a novel single phase boost converter. This motor can reduce the number of phase switch. And the permanent magnet which is used in the motor can improve...... the performance and efficiency of SR motor. However, the inherent characteristic of this motor is that the negative torque is very sensitive with the excitation current near the turn-on angle. The slow excitation current limits the torque generation region and reduces the average torque. Therefore, a novel single...... phase boost converter is applied to improve the performance of this motor. It is easy to generate a double dclink voltage and dc-link voltage and switch both of them. The voltage of boost capacitor is self balance, so the protective circuit is not need to consider. The fast excitation mode helps hybrid...

Comparison of motor and cognitive performance of children attending public and private day care centers

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Mariana M. Santos

2013-12-01

Full Text Available BACKGROUND: Given that environmental factors, such as the school environment, can influence child development, more attention should be paid to the development of children attending day care centers. OBJECTIVE: Todetermine whether there are differences in the gross motor, fine motor, or cognitive performances of children between 1 and3 years-old of similar socioeconomic status attending public and private day care centers full time. METHOD: Participants were divided into 2 groups, 1 of children attending public day care centers (69 children and another of children attending private day care centers (47 children. All children were healthy and regularly attended day care full time for over 4 months. To assess cognitive, gross and fine motor performance, the Bayley Scales of Infant and Toddler Development III was used. The Mann-Whitney test was used for comparative analyses between groups of children between 13 and 24 months, 25 and 41 months, and 13 and 41 months. RESULTS: Children in public day care centers exhibited lower scores on the cognitive development scale beginning at 13 months old. The fine and gross motor performance scores were lower in children over the age of 25 months attending public centers. Maternal education was not related to the performance of children in either group. CONCLUSION: The scores of cognitive performance as well as fine and gross motor performance of children of similar socioeconomic status who attend public day care centers are lower than children attending private daycare centers.

Avaliação do desempenho motor global e em habilidades motoras axiais e apendiculares de lactentes frequentadores de creche Assessment of global motor performance and gross and fine motor skills of infants attending day care centers

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Carolina T Souza

2010-08-01

Full Text Available OBJETIVO: Analisar o desempenho motor global em habilidades motoras axiais e apendiculares de lactentes que frequentavam, em tempo integral, duas Escolas Municipais de Educação Infantil. MÉTODOS: Estudo longitudinal do qual participaram 30 lactentes avaliados aos 12 e 17 meses de vida com a escala motora das Bayley Scales of Infant and Toddler Development-III, que possibilita a análise do desempenho motor global, apendicular e axial e a discrepância entre eles. Utilizaram-se o teste de Wilcoxon e o Coeficiente de Correlação de Spearman. RESULTADOS: A maioria dos participantes apresentou desempenho motor global dentro dos limites de normalidade, porém abaixo da média de referência aos 12 e 17 meses, com 30% classificados como suspeitos de atraso em pelo menos uma das avaliações. O desempenho motor axial foi inferior ao apendicular aos 12 e aos 17 meses, com grande discrepância entre eles especialmente na 2ª avaliação. Observou-se marcada variabilidade individual nas habilidades motoras apendiculares, com fraca correlação linear no desempenho entre a 1ª e a 2ª avaliações nesse domínio. Nas habilidades axiais e no desempenho motor global, encontrou-se menor variabilidade individual, com correlações moderadas e positivas entre a 1ª e a 2ª avaliações. Identificaram-se quatro lactentes com suspeita de atraso no desenvolvimento motor em ambas as avaliações. CONCLUSÕES: O estudo aponta necessidade de maior atenção ao desenvolvimento motor durante os primeiros 17 meses de crianças que frequentam creches, com especial vigilância à motricidade axial (considerando que ela é parte integrante do desenvolvimento global da criança e às crianças com desempenho suspeito de atraso em duas avaliações consecutivas.OBJECTIVE: To analyze the global motor performance and the gross and fine motor skills of infants attending two public child care centers full-time. METHODS: This was a longitudinal study that included 30 infants

Touch Screen Performance by Individuals With and Without Motor Control Disabilities

Science.gov (United States)

Chen, Karen B.; Savage, Anne B.; Chourasia, Amrish O.; Wiegmann, Douglas A.; Sesto, Mary E.

2012-01-01

Touch technology is becoming more prevalent as functionality improves and cost decreases. Therefore, it is important that this technology is accessible to users with diverse abilities. The objective of this study was to investigate the effects of button and gap size on performance by individuals with varied motor abilities. Participants with (n=38) and without (n=15) a motor control disability completed a digit entry task. Button size ranged from 10 to 30 mm and gap size was either 1 or 3 mm. Results indicated that as button size increased, there was a decrease in misses, errors, and time to complete tasks. Performance for the non-disabled group plateaued at button size 20mm, with minimal, if any gains observed with larger button sizes. In comparison, the disabled group’s performance continued to improve as button size increased. Gap size did not affect user performance. These results may help to improve accessibility of touch technology. PMID:23021630

Performance variation in motor imagery brain-computer interface: a brief review.

Science.gov (United States)

Ahn, Minkyu; Jun, Sung Chan

2015-03-30

Brain-computer interface (BCI) technology has attracted significant attention over recent decades, and has made remarkable progress. However, BCI still faces a critical hurdle, in that performance varies greatly across and even within subjects, an obstacle that degrades the reliability of BCI systems. Understanding the causes of these problems is important if we are to create more stable systems. In this short review, we report the most recent studies and findings on performance variation, especially in motor imagery-based BCI, which has found that low-performance groups have a less-developed brain network that is incapable of motor imagery. Further, psychological and physiological states influence performance variation within subjects. We propose a possible strategic approach to deal with this variation, which may contribute to improving the reliability of BCI. In addition, the limitations of current work and opportunities for future studies are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Determinants of gross motor skill performance in children with visual impairments.

Science.gov (United States)

Haibach, Pamela S; Wagner, Matthias O; Lieberman, Lauren J

2014-10-01

Children with visual impairments (CWVI) generally perform poorer in gross motor skills when compared with their sighted peers. This study examined the influence of age, sex, and severity of visual impairment upon locomotor and object control skills in CWVI. Participants included 100 CWVI from across the United States who completed the Test of Gross Motor Development II (TGMD-II). The TGMD-II consists of 12 gross motor skills including 6 object control skills (catching, kicking, striking, dribbling, throwing, and rolling) and 6 locomotor skills (running, sliding, galloping, leaping, jumping, and hopping). The full range of visual impairments according to United States Association for Blind Athletes (USABA; B3=20/200-20/599, legally blind; B2=20/600 and up, travel vision; B1=totally blind) were assessed. The B1 group performed significantly worse than the B2 (0.000 ≤ p ≤ 0.049) or B3 groups (0.000 ≤ p ≤ 0.005); however, there were no significant differences between B2 and B3 except for the run (p=0.006), catch (p=0.000), and throw (p=0.012). Age and sex did not play an important role in most of the skills, with the exception of boys outperforming girls striking (p=0.009), dribbling (p=0.013), and throwing (p=0.000), and older children outperforming younger children in dribbling (p=0.002). The significant impact of the severity of visual impairment is likely due to decreased experiences and opportunities for children with more severe visual impairments. In addition, it is likely that these reduced experiences explain the lack of age-related differences in the CWVI. The large disparities in performance between children who are blind and their partially sighted peers give direction for instruction and future research. In addition, there is a critical need for intentional and specific instruction on motor skills at a younger age to enable CWVI to develop their gross motor skills. Copyright © 2014 Elsevier Ltd. All rights reserved.

Performance test of a 1 MW class HTS synchronous motor for industrial application

International Nuclear Information System (INIS)

Kwon, Y.K.; Kim, H.M.; Baik, S.K.; Lee, E.Y.; Lee, J.D.; Kim, Y.C.; Lee, S.H.; Hong, J.P.; Jo, Y.S.; Ryu, K.S.

2008-01-01

This paper deals with development activities of high temperature superconducting (HTS) synchronous motor at DOOSAN heavy industry and Korea Electrotechnology Research Institute (KERI) in Korea, and is sponsored by DAPAS program which is supported by Korean government. The final aim of the project is realization of HTS motor in the field of industry such as large driving pumps, fans and compressors for utility and industrial environments. At present time, 1 MW HTS motor is developed for the purpose to fully represent the design and manufacturing issues for the larger capacity machine. The number of pole and rotating speed of machine are 2 pole and 3600 rpm. The HTS field coil of the developed motor is cooled by way of neon thermosyphon mechanism and the stator coil is cooled by water through hollow copper conductor. This paper describes status of 1 MW HTS motor development, such as design, fabrication and performance test results, which was conducted at steady state in generator mode and motor mode

Model reference adaptive vector control for induction motor without speed sensor

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Bo Fan

2017-01-01

Full Text Available The wide applications of vector control improve the high-accuracy performance of alternating current (AC adjustable speed system. In order to obverse the full-order flux and calculate the real-time speed, this article introduces the motor T equivalent circuit to build a full-order flux observer model, where the current and flux variables of stator and rotor are adopted. Model reference adaptive control is introduced to build the AC motor flux observer. The current output is used as feedback to build the feedback matrix. The calculation method of motor speed, which is part of the inputs of flux observation, is applied to realize the adaptive control. The concept of characteristic function is introduced to calculate the flux, of which the foundation is the variables of composite form of voltage and current models. The characteristic function is deduced as a relative-state variable function. The feedback matrix is improved and designed to ensure the motor flux observer is a smooth switch between current and voltage model in low and high speeds, respectively. Experimental results show that the feedback and characteristic model are feasible, and the vector control with speed sensorless based on the full-order flux observer has better performance and anti-disturbance.

Characteristics of the Motor Units during Sternocleidomastoid Isometric Flexion among Patients with Mechanical Neck Disorder and Asymptomatic Individuals.

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Chia-Chi Yang

Full Text Available Mechanical neck disorder is a widespread and non-neurological musculoskeletal condition resulting from modern lifestyles. Presently, the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles and the characteristics of the short-term synchronization of the motor unit in patients with neck pain are ambiguous. This study therefore aims to clarify the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles in patients with mechanical neck disorder and in asymptomatic individuals. We further investigated whether alterations in the degree of motor unit short-term synchronization occur. The surface electrophysiological signals of the bilateral sternal heads of the sternocleidomastoid muscles of twelve patients with mechanical neck disorder and asymptomatic individuals were detected at 25% of the maximum voluntary contraction during cervical isometric flexion and then decomposed into individual motor unit action potential trains. We found that the patients with mechanical neck disorder showed significantly higher initial and mean firing rates of the sternocleidomastoid muscles and displayed substantially lower motor unit short-term synchronization values compared with the asymptomatic subjects. Consequently, these convincing findings support the assertion that patients with mechanical neck disorder display altered neuromuscular control strategies, such as the reinforcement of motor unit recruitment firing rates in the sternocleidomastoid muscles. The motor units of these patients also revealed neural recruitment strategies with relatively poor efficiency when executing the required motor tasks.

Characteristics of the Motor Units during Sternocleidomastoid Isometric Flexion among Patients with Mechanical Neck Disorder and Asymptomatic Individuals.

Science.gov (United States)

Yang, Chia-Chi; Su, Fong-Chin; Yang, Po-Ching; Lin, Hwai-Ting; Guo, Lan-Yuen

2016-01-01

Mechanical neck disorder is a widespread and non-neurological musculoskeletal condition resulting from modern lifestyles. Presently, the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles and the characteristics of the short-term synchronization of the motor unit in patients with neck pain are ambiguous. This study therefore aims to clarify the fundamental electrophysiological properties of the motor units of the sternocleidomastoid muscles in patients with mechanical neck disorder and in asymptomatic individuals. We further investigated whether alterations in the degree of motor unit short-term synchronization occur. The surface electrophysiological signals of the bilateral sternal heads of the sternocleidomastoid muscles of twelve patients with mechanical neck disorder and asymptomatic individuals were detected at 25% of the maximum voluntary contraction during cervical isometric flexion and then decomposed into individual motor unit action potential trains. We found that the patients with mechanical neck disorder showed significantly higher initial and mean firing rates of the sternocleidomastoid muscles and displayed substantially lower motor unit short-term synchronization values compared with the asymptomatic subjects. Consequently, these convincing findings support the assertion that patients with mechanical neck disorder display altered neuromuscular control strategies, such as the reinforcement of motor unit recruitment firing rates in the sternocleidomastoid muscles. The motor units of these patients also revealed neural recruitment strategies with relatively poor efficiency when executing the required motor tasks.

A CFD study of Screw Compressor Motor Cooling Analysis

Science.gov (United States)

Branch, S.

2017-08-01

Screw compressors use electric motors to drive the male screw rotor. They are cooled by the suction refrigerant vapor that flows around the motor. The thermal conditions of the motor can dramatically influence the performance and reliability of the compressor. The more optimized this flow path is, the better the motor performance. For that reason it is important to understand the flow characteristics around the motor and the motor temperatures. Computational fluid dynamics (CFD) can be used to provide a detailed analysis of the refrigerant’s flow behavior and motor temperatures to identify the undesirable hot spots in the motor. CFD analysis can be used further to optimize the flow path and determine the reduction of hot spots and cooling effect. This study compares the CFD solutions of a motor cooling model to a motor installed with thermocouples measured in the lab. The compressor considered for this study is an R134a screw compressor. The CFD simulation of the motor consists of a detailed breakdown of the stator and rotor components. Orthotropic thermal conductivity material properties are used to represent the simplified motor geometry. In addition, the analysis includes the motor casings of the compressor to draw heat away from the motor by conduction. The study will look at different operating conditions and motor speeds. Finally, the CFD study will investigate the predicted motor temperature change by varying the vapor mass flow rates and motor speed. Recommendations for CFD modeling of such intricate heat transfer phenomenon have thus been proposed.

Motor Skill Performance by Low SES Preschool and Typically Developing Children on the PDMS-2

Science.gov (United States)

Liu, Ting; Hoffmann, Chelsea; Hamilton, Michelle

2017-01-01

The purpose of this study was to compare the motor skill performance of preschool children from low socioeconomic (SES) backgrounds to their age matched typically developing peers using the Peabody Developmental Motor Scales-2 (PDMS-2). Sixty-eight children (34 low SES and 34 typically developing; ages 3-5) performed the PDMS-2. Standard scores…

Using the motor to monitor pump conditions

International Nuclear Information System (INIS)

Casada, D.

1996-01-01

When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented

Using the motor to monitor pump conditions

Energy Technology Data Exchange (ETDEWEB)

Casada, D. [Oak Ridge National Lab., TN (United States)

1996-12-01

When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented.

The relative age effect in the German Football TID Programme: biases in motor performance diagnostics and effects on single motor abilities and skills in groups of selected players.

Science.gov (United States)

Votteler, Andreas; Höner, Oliver

2014-01-01

This study examined the disturbing effects of relative age on the talent identification process in the talent development programme of the German Football Association. The bias in the selection rate was examined via the extent of relative age effects. The bias in motor performance diagnostics was analysed by comparing the motor performance of selected players with normal motor development. The mechanisms underlying the relative age biases in motor performance were examined by modelling the direct and indirect effects of relative age on single motor performance tests for sprint, running agility, dribbling and ball passing and control. Data from 10,130 selected football players from the U12 to U15 age groups were collected in autumn 2010. The birth distribution differed significantly from the reference population with approximately 61% of the players born in the first half of the year. The selection probability was approximately two times higher for players born in the first quarter of the year than for players born in the last quarter. Revised motor performance diagnostics showed better results on average for relatively younger players. Path analysis revealed significant direct and indirect relative age effects for physiologically demanding tests and almost no effects for technically demanding tests. Large sample sizes allowed high resolution in relative age with additional informational content and multivariate modelling of the complex relationships among relative age, physical development and motor performance. The results are discussed on how relative age affects the effectiveness and fairness of talent identification and development processes.

High variability impairs motor learning regardless of whether it affects task performance.

Science.gov (United States)

Cardis, Marco; Casadio, Maura; Ranganathan, Rajiv

2018-01-01

Motor variability plays an important role in motor learning, although the exact mechanisms of how variability affects learning are not well understood. Recent evidence suggests that motor variability may have different effects on learning in redundant tasks, depending on whether it is present in the task space (where it affects task performance) or in the null space (where it has no effect on task performance). We examined the effect of directly introducing null and task space variability using a manipulandum during the learning of a motor task. Participants learned a bimanual shuffleboard task for 2 days, where their goal was to slide a virtual puck as close as possible toward a target. Critically, the distance traveled by the puck was determined by the sum of the left- and right-hand velocities, which meant that there was redundancy in the task. Participants were divided into five groups, based on both the dimension in which the variability was introduced and the amount of variability that was introduced during training. Results showed that although all groups were able to reduce error with practice, learning was affected more by the amount of variability introduced rather than the dimension in which variability was introduced. Specifically, groups with higher movement variability during practice showed larger errors at the end of practice compared with groups that had low variability during learning. These results suggest that although introducing variability can increase exploration of new solutions, this may adversely affect the ability to retain the learned solution. NEW & NOTEWORTHY We examined the role of introducing variability during motor learning in a redundant task. The presence of redundancy allows variability to be introduced in different dimensions: the task space (where it affects task performance) or the null space (where it does not affect task performance). We found that introducing variability affected learning adversely, but the amount of

Dynamic response characteristics evaluation of hydrostatic bearing in hydraulic piston pump/motor

International Nuclear Information System (INIS)

Ham, Young Bog; Yun, So Nam; Kim, Dong Soo; Choi, Byoung Oh; Kim, Sung Dong

2001-01-01

In swash plate type axial piston hydraulic pump and motor, the piston shoe is periodically pressurized with square function shape by supply pressure load as rotation of cylinder barrel. Therefore the recess pressure ono bottom part of piston shoe is suddenly increase through orifice in the piston shoe. In this study, we simulated that the frequency response of the recess pressure against with change of supply pressure with analysis tool. Also, we evaluate the dynamic response characteristics of overbalanced hydrostatic bearing with change of the orifice diameter

WHICH MOTOR ABILITIES HAVE THE HIGHEST IMPACT ON WORKING PERFORMANCE OF SLOVENIAN SOLDIERS?

Directory of Open Access Journals (Sweden)

Maja Pori

2010-09-01

Full Text Available The objective of the research was to find a correlation between motor abilities and working efficiency of soldiers in a battle unit of Slovenia Armed Forces (SAF. The subject consisted of 115 soldiers (age = 27,1 ± 3,7 years who were serving in the first brigade of the SAF. Motor abilities were measured with 11 motor tests, assessing the level of flexibility, speed, strength and coordination. To evaluate working efficiency of soldiers a special questionnaire was used, which consisted of 19 statements. Superior officer was asked to fill a questionnaire for each inferior soldier with values from 1 to 5. The correlation between motor abilities and working efficiency was assessed with the Pearson’s correlation coefficient. We have found 5 statistically significant correlations. Motor tests correlating most with working performance were tests of arm strength.

Does the Animal Fun program improve motor performance in children aged 4-6 years?

Science.gov (United States)

Piek, J P; McLaren, S; Kane, R; Jensen, L; Dender, A; Roberts, C; Rooney, R; Packer, T; Straker, L

2013-10-01

The Animal Fun program was designed to enhance the motor ability of young children by imitating the movements of animals in a fun, inclusive setting. The efficacy of this program was investigated through a randomized controlled trial using a multivariate nested cohort design. Pre-intervention scores were recorded for 511 children aged 4.83 years to 6.17 years (M=5.42 years, SD=3.58 months). Six control and six intervention schools were compared 6 months later following the intervention, and then again at 18 months after the initial testing when the children were in their first school year. Changes in motor performance were examined using the Bruininks-Oseretsky Test of Motor Proficiency short form. Data were analyzed using multi-level-mixed effects linear regression. A significant Condition×Time interaction was found, F(2,1219)=3.35, p=.035, demonstrating that only the intervention group showed an improvement in motor ability. A significant Sex×Time interaction was also found, F(2,1219)=3.84, p=.022, with boys improving over time, but not girls. These findings have important implications for the efficacy of early intervention of motor skills and understanding the differences in motor performance between boys and girls. Copyright © 2012 Elsevier B.V. All rights reserved.

RELIABILITY OF ANKLE-FOOT MORPHOLOGY, MOBILITY, STRENGTH, AND MOTOR PERFORMANCE MEASURES.

Science.gov (United States)

Fraser, John J; Koldenhoven, Rachel M; Saliba, Susan A; Hertel, Jay

2017-12-01

Assessment of foot posture, morphology, intersegmental mobility, strength and motor control of the ankle-foot complex are commonly used clinically, but measurement properties of many assessments are unclear. To determine test-retest and inter-rater reliability, standard error of measurement, and minimal detectable change of morphology, joint excursion and play, strength, and motor control of the ankle-foot complex. Reliability study. 24 healthy, recreationally-active young adults without history of ankle-foot injury were assessed by two clinicians on two occasions, three to ten days apart. Measurement properties were assessed for foot morphology (foot posture index, total and truncated length, width, arch height), joint excursion (weight-bearing dorsiflexion, rearfoot and hallux goniometry, forefoot inclinometry, 1 st metatarsal displacement) and joint play, strength (handheld dynamometry), and motor control rating during intrinsic foot muscle (IFM) exercises. Clinician order was randomized using a Latin Square. The clinicians performed independent examinations and did not confer on the findings for the duration of the study. Test-retest and inter-tester reliability and agreement was assessed using intraclass correlation coefficients (ICC 2,k ) and weighted kappa ( K w ). Test-retest reliability ICC were as follows: morphology: .80-1.00, joint excursion: .58-.97, joint play: -.67-.84, strength: .67-.92, IFM motor rating: K W -.01-.71. Inter-rater reliability ICC were as follows: morphology: .81-1.00, joint excursion: .32-.97, joint play: -1.06-1.00, strength: .53-.90, and IFM motor rating: K w .02-.56. Measures of ankle-foot posture, morphology, joint excursion, and strength demonstrated fair to excellent test-retest and inter-rater reliability. Test-retest reliability for rating of perceived difficulty and motor performance was good to excellent for short-foot, toe-spread-out, and hallux exercises and poor to fair for lesser toe extension. Joint play measures had

Development of a dc motor with virtually zero powered magnetic bearing

Science.gov (United States)

1971-01-01

The development of magnetic bearings for use in direct current electric motors is discussed. The characteristics of the magnets used in the construction of the bearings are described. A magnetic bearing using steel armoring on permanent magnets was selected for performance tests. The specifications of the motor are presented. The test equipment used in the evaluation is described.

Comparison of Unmodulated Current Control Characteristics of Permanent Magnet Synchronous Motor

Directory of Open Access Journals (Sweden)

Anwar Muqorobin

2014-12-01

Full Text Available This paper discusses comparison of unmodulated current controls in PMSM, more specifically, on-off, sliding mode, predictive and hybrid controls. The purpose of this study is to select the most appropriate control technique to be adopted. The comparison method is preceded by modeling the motor and entering the values of the motor parameters. PI control is used for speed control and zero d-axis current is employed. Furthermore, performing simulation for each type ofthe selected current controls and analyzing their responses in terms of dq and abc currents, q-axis current response with step reference, as well as THD. Simulation results show that the on-off control gives the best overall performance based on its abc-axis current ripple and THD at large load torque. The hybrid control shows the best response occurring only at the fastest transient time of q-axis current but its response exhibits bad qualities compared with other controls. The predictive control yields the best responses offering the smallest d-axis ripple current and THD at small load torque condition. The sliding mode control, however, does not exhibit any prominent performance compared to the others. Results presented in this paper further indicate that for the PMSM used in the simulation the most appropriate control is the predictive control.

The effect of amblyopia on fine motor skills in children.

Science.gov (United States)

Webber, Ann L; Wood, Joanne M; Gole, Glen A; Brown, Brian

2008-02-01

In an investigation of the functional impact of amblyopia in children, the fine motor skills of amblyopes and age-matched control subjects were compared. The influence of visual factors that might predict any decrement in fine motor skills was also explored. Vision and fine motor skills were tested in a group of children (n = 82; mean age, 8.2 +/- 1.7 [SD] years) with amblyopia of different causes (infantile esotropia, n = 17; acquired strabismus, n = 28; anisometropia, n = 15; mixed, n = 13; and deprivation n = 9), and age-matched control children (n = 37; age 8.3 +/- 1.3 years). Visual motor control (VMC) and upper limb speed and dexterity (ULSD) items of the Bruininks-Oseretsky Test of Motor Proficiency were assessed, and logMAR visual acuity (VA) and Randot stereopsis were measured. Multiple regression models were used to identify the visual determinants of fine motor skills performance. Amblyopes performed significantly poorer than control subjects on 9 of 16 fine motor skills subitems and for the overall age-standardized scores for both VMC and ULSD items (P multiple regression model that took into account the intercorrelation between visual characteristics, poorer fine motor skills performance was associated with strabismus (F(1,75) = 5.428; P = 0.022), but not with the level of binocular function, refractive error, or visual acuity in either eye. Fine motor skills were reduced in children with amblyopia, particularly those with strabismus, compared with control subjects. The deficits in motor performance were greatest on manual dexterity tasks requiring speed and accuracy.

Profiles of Motor Laterality in Young Athletes' Performance of Complex Movements: Merging the MOTORLAT and PATHoops Tools

Science.gov (United States)

Castañer, Marta; Andueza, Juan; Hileno, Raúl; Puigarnau, Silvia; Prat, Queralt; Camerino, Oleguer

2018-01-01

Laterality is a key aspect of the analysis of basic and specific motor skills. It is relevant to sports because it involves motor laterality profiles beyond left-right preference and spatial orientation of the body. The aim of this study was to obtain the laterality profiles of young athletes, taking into account the synergies between the support and precision functions of limbs and body parts in the performance of complex motor skills. We applied two instruments: (a) MOTORLAT, a motor laterality inventory comprising 30 items of basic, specific, and combined motor skills, and (b) the Precision and Agility Tapping over Hoops (PATHoops) task, in which participants had to perform a path by stepping in each of 14 hoops arranged on the floor, allowing the observation of their feet, left-right preference and spatial orientation. A total of 96 young athletes performed the PATHoops task and the 30 MOTORLAT items, allowing us to obtain data about limb dominance and spatial orientation of the body in the performance of complex motor skills. Laterality profiles were obtained by means of a cluster analysis and a correlational analysis and a contingency analysis were applied between the motor skills and spatial orientation actions performed. The results obtained using MOTORLAT show that the combined motor skills criterion (for example, turning while jumping) differentiates athletes' uses of laterality, showing a clear tendency toward mixed laterality profiles in the performance of complex movements. In the PATHoops task, the best spatial orientation strategy was “same way” (same foot and spatial wing) followed by “opposite way” (opposite foot and spatial wing), in keeping with the research assumption that actions unfolding in a horizontal direction in front of an observer's eyes are common in a variety of sports. PMID:29930527

Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

Science.gov (United States)

Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

2017-06-22

This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

Synchronous motor with soft start element formed between the motor rotor and motor output shaft to successfully synchronize loads that have high inertia and/or high torque

Science.gov (United States)

Umans, Stephen D; Nisley, Donald L; Melfi, Michael J

2014-10-28

A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

Daily-life tele-monitoring of motor performance in stroke survivors

NARCIS (Netherlands)

Veltink, Petrus H.; van Meulen, Fokke; van Beijnum, Bernhard J.F.; Klaassen, Bart; Hermens, Hermanus J.; Droog, Adriaan; Weusthof, Marcel H.H.; Lorussi, F.; Tognetti, A.; Reenalda, J.; Reenalda, Jasper; Nikamp, C.D.M.; Nikamp-Simons, Corien Diana Maria; Baten, Christian T.M.; Buurke, Jaap; Held, J.; Luft, A.; Luinge, H.; De Toma, G.; Mancuso, C.; Paradiso, R.; Aminian, Kamiar

2014-01-01

The objective of the EU project INTERACTION is to develop an unobtrusive and modular sensing system for objective monitoring of daily-life motor performance of stroke survivors. This will enable clinical professionals to advise their patients about their continued daily-life activity profile and

Characteristics of motor speech phenotypes in multiple sclerosis.

Science.gov (United States)

Rusz, Jan; Benova, Barbora; Ruzickova, Hana; Novotny, Michal; Tykalova, Tereza; Hlavnicka, Jan; Uher, Tomas; Vaneckova, Manuela; Andelova, Michaela; Novotna, Klara; Kadrnozkova, Lucie; Horakova, Dana

2018-01-01

Motor speech disorders in multiple sclerosis (MS) are poorly understood and their quantitative, objective acoustic characterization remains limited. Additionally, little data regarding relationships between the severity of speech disorders and neurological involvement in MS, as well as the contribution of pyramidal and cerebellar functional systems on speech phenotypes, is available. Speech data were acquired from 141 MS patients with Expanded Disability Status Scale (EDSS) ranging from 1 to 6.5 and 70 matched healthy controls. Objective acoustic speech assessment including subtests on phonation, oral diadochokinesis, articulation and prosody was performed. The prevalence of dysarthria in our MS cohort was 56% while the severity was generally mild and primarily consisted of a combination of spastic and ataxic components. Prosodic-articulatory disorder presenting with monopitch, articulatory decay, excess loudness variations and slow rate was the most salient. Speech disorders reflected subclinical motor impairment with 78% accuracy in discriminating between a subgroup of asymptomatic MS (EDSS oral diadochokinesis and the 9-Hole Peg Test (r = - 0.65, p oral diadochokinesis and excess loudness variations significantly separated pure pyramidal and mixed pyramidal-cerebellar MS subgroups. Automated speech analyses may provide valuable biomarkers of disease progression in MS as dysarthria represents common and early manifestation that reflects disease disability and underlying pyramidal-cerebellar pathophysiology. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of Thrust Characteristics in Pencil Sized Cylinder-type Linear Motors with Different Magnet Arrays

OpenAIRE

Nakaiwa, K; Yamada, A; Tashiro, K; Wakiwaka, H

2009-01-01

From a strong demand on the miniaturization of a chip mounter or a semiconductor device, the thrust improvement considering the magnets arrangement is studied. We accept a core stator with a Halbach type magnet array for a current linear motor. The thrust characteristics are compared with two kinds of mover, a NS magnet array and a Halbach magnet array.

The performance of the DC motor by the PID controlling PWM DC-DC boost converter

OpenAIRE

Can, Erol; Sayan, Hasan Hüseyin

2017-01-01

This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...

Principle and Basic Characteristics of Variable-Magnetic-Force Memory Motors

Science.gov (United States)

Sakai, Kazuto; Yuki, Kazuaki; Hashiba, Yutaka; Takahashi, Norio; Yasui, Kazuya; Kovudhikulrungsri, Lilit

A reduction in the power consumed by motors is required for energy saving in the case of electrical appliances and electric vehicles (EV). The motors used for operating these apparatus operate at variable speeds. Further, the motors operate with small load in stationary mode and with large load in start-up mode. A permanent magnet motor can operate at the rated power with a high efficiency. However, the efficiency is lower at small load or high speed because the large constant magnetic force results in substantial core loss. Furthermore, the flux-weakening current that depresses voltage at high speed leads to significant copper loss. Therefore, we have developed a new technique for controlling the magnetic force of permanent magnet on the basis of the load or speed of the motor. In this paper, we propose the novel motor that can vary magnetic flux and we clarify the principle.

Sleep and memory consolidation: motor performance and proactive interference effects in sequence learning.

Science.gov (United States)

Borragán, Guillermo; Urbain, Charline; Schmitz, Rémy; Mary, Alison; Peigneux, Philippe

2015-04-01

That post-training sleep supports the consolidation of sequential motor skills remains debated. Performance improvement and sensitivity to proactive interference are both putative measures of long-term memory consolidation. We tested sleep-dependent memory consolidation for visuo-motor sequence learning using a proactive interference paradigm. Thirty-three young adults were trained on sequence A on Day 1, then had Regular Sleep (RS) or were Sleep Deprived (SD) on the night after learning. After two recovery nights, they were tested on the same sequence A, then had to learn a novel, potentially competing sequence B. We hypothesized that proactive interference effects on sequence B due to the prior learning of sequence A would be higher in the RS condition, considering that proactive interference is an indirect marker of the robustness of sequence A, which should be better consolidated over post-training sleep. Results highlighted sleep-dependent improvement for sequence A, with faster RTs overnight for RS participants only. Moreover, the beneficial impact of sleep was specific to the consolidation of motor but not sequential skills. Proactive interference effects on learning a new material at Day 4 were similar between RS and SD participants. These results suggest that post-training sleep contributes to optimizing motor but not sequential components of performance in visuo-motor sequence learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Computer simulation of a 3-phase induction motor

International Nuclear Information System (INIS)

Memon, N.A.; Unsworth, P.J.

2004-01-01

Computer Simulation of a 3-phase squirrel-cage induction motor is presented in Microsoft QBASIC for understanding trends and various operational modes of an induction motor. Thyristor fed, phase controlled induction motor (three-wire) model has been simulated. In which voltage is applied to the motor stator winding through back-to-back connected thyristors as controlled switches in series with the stator. The simulated induction motor system opens up towards a wide range of investigation/analysis options for research and development work in the field. Key features of the simulation performed are highlighted for development of better understanding of the work done. Complete study of an Induction Motor, starting modes in terms the voltage/current, torque/speed characteristics and their graphical representation produced is presented. Ideal agreement of the simulation results with the notional outcome encourages users to go ahead for various hardware development projects based on the study through the simulation. (author)

Deficits in motor abilities and developmental fractionation of imitation performance in high-functioning autism spectrum disorders.

Science.gov (United States)

Biscaldi, Monica; Rauh, Reinhold; Irion, Lisa; Jung, Nikolai H; Mall, Volker; Fleischhaker, Christian; Klein, Christoph

2014-07-01

The co-occurrence of motor and imitation disabilities often characterises the spectrum of deficits seen in patients with autism spectrum disorders (ASD). Whether these seemingly separate deficits are inter-related and whether, in particular, motor deficits contribute to the expression of imitation deficits is the topic of the present study and was investigated by comparing these deficits' cross-sectional developmental trajectories. To that end, different components of motor performance assessed in the Zurich Neuromotor Assessment and imitation abilities for facial movements and non-meaningful gestures were tested in 70 subjects (aged 6-29 years), including 36 patients with high-functioning ASD and 34 age-matched typically developed (TD) participants. The results show robust deficits in probands with ASD in timed motor performance and in the quality of movement, which are all independent of age, with one exception. Only diadochokinesis improves moderately with increasing age in ASD probands. Imitation of facial movements and of non-meaningful hand, finger, hand finger gestures not related to social context or tool use is also impaired in ASD subjects, but in contrast to motor performance this deficit overall improves with age. A general imitation factor, extracted from the highly inter-correlated imitation tests, is differentially correlated with components of neuromotor performance in ASD and TD participants. By developmentally fractionating developmentally stable motor deficits from developmentally dynamic imitation deficits, we infer that imitation deficits are primarily cognitive in nature.

cTBS disruption of the supplementary motor area perturbs cortical sequence representation but not behavioural performance.

Science.gov (United States)

Solopchuk, Oleg; Alamia, Andrea; Dricot, Laurence; Duque, Julie; Zénon, Alexandre

2017-12-01

Neuroimaging studies have repeatedly emphasized the role of the supplementary motor area (SMA) in motor sequence learning, but interferential approaches have led to inconsistent findings. Here, we aimed to test the role of the SMA in motor skill learning by combining interferential and neuroimaging techniques. Sixteen subjects were trained on simple finger movement sequences for 4 days. Afterwards, they underwent two neuroimaging sessions, in which they executed both trained and novel sequences. Prior to entering the scanner, the subjects received inhibitory transcranial magnetic stimulation (TMS) over the SMA or a control site. Using multivariate fMRI analysis, we confirmed that motor training enhances the neural representation of motor sequences in the SMA, in accordance with previous findings. However, although SMA inhibition altered sequence representation (i.e. between-sequence decoding accuracy) in this area, behavioural performance remained unimpaired. Our findings question the causal link between the neuroimaging correlate of elementary motor sequence representation in the SMA and sequence generation, calling for a more thorough investigation of the role of this region in performance of learned motor sequences. Copyright © 2017 Elsevier Inc. All rights reserved.

Performance Analysis of Three-Phase Induction Motor with AC Direct and VFD

Science.gov (United States)

Kumar, Dinesh

2018-03-01

The electrical machine analysis and performance calculation is a very important aspect of efficient drive system design. The development of power electronics devices and power converters provide smooth speed control of Induction Motors by changing the frequency of input supply. These converters, on one hand are providing a more flexible speed control that also leads to problems of harmonics and their associated ailments like pulsating torque, distorted current and voltage waveforms, increasing losses etc. This paper includes the performance analysis of three phase induction motor with three-phase AC direct and variable frequency drives (VFD). The comparison has been concluded with respect to various parameters. MATLAB-SIMULINKTM is used for the analysis.

The relationship of overweight and obesity to the motor performance ...

African Journals Online (AJOL)

Objectives: This study aimed to determine the relationship between overweight and obesity and the motor performance of nine- to 13-year-old South African children. Design: The study used a one-way cross-sectional design based on baseline measurements. Settings and subjects: The research group comprised 280 ...

RELATIONS OF THE MORPHOLOGICAL CHARACTERISTICS AND MOTOR ABILITIES WITH JUMP FOWRARD AND TRIPLE JUMP OF STUDENTS AT THE FACULTY OF SCIENCE AND SPORT

OpenAIRE

Rashiti Naser; Ajvazi Vlora; Adem Nura; Fadil Nika

2011-01-01

In order to examine the impact of anthropometrical characteristics and motor skills during the tests’ implementation of the jump forward and triple jump from place, the experimental research was carried out on a sample of 100 second year students from the Faculty of Physical Education and Sport in Prishtine. For the purposes of this study were measured eight anthropometrical characteristics and ten tests for assessing motor skills, which made the predictor system of variables. To assess the e...

Study of linear induction motor characteristics : the Mosebach model

Science.gov (United States)

1976-05-31

This report covers the Mosebach theory of the double-sided linear induction motor, starting with the ideallized model and accompanying assumptions, and ending with relations for thrust, airgap power, and motor efficiency. Solutions of the magnetic in...

Study of linear induction motor characteristics : the Oberretl model

Science.gov (United States)

1975-05-30

The Oberretl theory of the double-sided linear induction motor (LIM) is examined, starting with the idealized model and accompanying assumptions, and ending with relations for predicted thrust, airgap power, and motor efficiency. The effect of varyin...

Motor carrier industry profile study : financial and operating performance profiles by industry segment, 2001-2002.

Science.gov (United States)

2004-09-01

This report profiles the motor carrier industry and its significant operating segments. It is one of a series of reports analyzing various aspects of the motor carrier industry. Other reports in the series focus on the safety performance of the indus...

Magnetic suspension motorized spindle-cutting system dynamics analysis and vibration control review

Directory of Open Access Journals (Sweden)

Xiaoli QIAO

2016-10-01

Full Text Available The performance of high-speed spindle directly determines the development of high-end machine tools. The cutting system's dynamic characteristics and vibration control effect are inseparable with the performance of the spindle,which influence each other, synergistic effect together the cutting efficiency, the surface quality of the workpiece and tool life in machining process. So, the review status on magnetic suspension motorized spindle, magnetic suspension bearing-flexible rotor system dynamics modeling theory and status of active control technology of flexible magnetic suspension motorized spindle rotor vibration are studied, and the problems which present in the magnetic suspension flexible motorized spindle rotor systems are refined, and the development trend of magnetic levitation motorized spindle and the application prospect is forecasted.

Performance Characteristics of a Cross-Flow Hydrokinetic Turbine under Unsteady Conditions

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Flack, Karen; Lust, Ethan; Bailin, Ben

2017-11-01

Performance characteristics are presented for a cross-flow hydrokinetic turbine designed for use in a riverine environment. The test turbine is a 1:6 scale model of a three-bladed device (9.5 m span, 6.5 m diameter) that has been proposed by the Department of Energy. Experiments are conducted in the large towing tank (116 m long, 7.9 m wide, 5 m deep) at the United States Naval Academy. The turbine is towed beneath a moving carriage at a constant speed in combination with a shaft motor to achieve the desired tip speed ratio (TSR) range. The measured quantities of turbine thrust, torque and RPM result in power and thrust coefficients for a range of TSR. Results will be presented for cases with quiescent flow at a range of Reynolds numbers and flow with mild surface waves, representative of riverine environments. The impact of unsteady flow conditions on the average turbine performance was not significant. Unsteady flow conditions did have an impact on instantaneous turbine performance which operationally would result in unsteady blade loading and instantaneous power quality.

Motor of Lift RSG-GAS Performance Analysis after Repair

International Nuclear Information System (INIS)

Asep-Saepuloh; Yayan-Andriyanto; Yuyut-Suraniyanto

2006-01-01

The out of order an equipment is ordinary natural process happened, above all the equipment be used continually with very old time, as for as out of order can be resulted from kinds of cause. Lift motor out of order can be result by motor is broken or happened the body shorten then affected do not function it the lift, so until done rewinding process. The rewinding is furl to repeat at motor coils. Motor of Lift represent main activator machine turning around shares pulley. Lift Motor will work if there is called in normal operation condition or the moment manual switch if done maintenance. Motor used at lift is motor three phases with two speeds that is low speed and high speed. Rewinding process must be done removed the motor from Lift machine and have to be done by professional workshop. In during function test take place, temperature at coil reach 70 o C (exceeding boundary permitted). After done installation addition thermal at motor coil hence his temperature become normal that is only reach 50 o C. (author)

School-Based Fundamental-Motor-Skill Intervention for Children With Autism-Like Characteristics: An Exploratory Study.

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Bremer, Emily; Lloyd, Meghann

2016-01-01

The purpose of this pilot study was to demonstrate the impact of a fundamental-motor-skill (FMS) intervention on the motor skills of 3- to 7-year-old children with autism-like characteristics in an early intervention classroom. A secondary purpose was to qualitatively assess the impact of the program as described by the classroom's special education teacher. All children in the classroom (N = 5) took part in an FMS intervention for two 6-wk blocks (fall 2013 and winter 2014). Motor-skill proficiency and social skills were assessed at 3 times: baseline, after Block 1 of the intervention, and after Block 2 of the intervention. In addition, an interview was conducted with the classroom teacher after Assessment 3 to draw further insights into the relative success and impact of the program. Results were analyzed through a visual analysis and presented individually. They indicated improvements in the participants' individual FMS and social-skill scores, possible improvements in declarative knowledge, and an increase in the special education teacher's readiness to teach FMS; further research with larger, controlled samples is warranted.

Conveyor Performance based on Motor DC 12 Volt Eg-530ad-2f using K-Means Clustering

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Arifin, Zaenal; Artini, Sri DP; Much Ibnu Subroto, Imam

2017-04-01

To produce goods in industry, a controlled tool to improve production is required. Separation process has become a part of production process. Separation process is carried out based on certain criteria to get optimum result. By knowing the characteristics performance of a controlled tools in separation process the optimum results is also possible to be obtained. Clustering analysis is popular method for clustering data into smaller segments. Clustering analysis is useful to divide a group of object into a k-group in which the member value of the group is homogeny or similar. Similarity in the group is set based on certain criteria. The work in this paper based on K-Means method to conduct clustering of loading in the performance of a conveyor driven by a dc motor 12 volt eg-530-2f. This technique gives a complete clustering data for a prototype of conveyor driven by dc motor to separate goods in term of height. The parameters involved are voltage, current, time of travelling. These parameters give two clusters namely optimal cluster with center of cluster 10.50 volt, 0.3 Ampere, 10.58 second, and unoptimal cluster with center of cluster 10.88 volt, 0.28 Ampere and 40.43 second.

Transcranial direct current stimulation over multiple days enhances motor performance of a grip task.

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Fan, Julie; Voisin, Julien; Milot, Marie-Hélène; Higgins, Johanne; Boudrias, Marie-Hélène

2017-09-01

Recovery of handgrip is critical after stroke since it is positively related to upper limb function. To boost motor recovery, transcranial direct current stimulation (tDCS) is a promising, non-invasive brain stimulation technique for the rehabilitation of persons with stroke. When applied over the primary motor cortex (M1), tDCS has been shown to modulate neural processes involved in motor learning. However, no studies have looked at the impact of tDCS on the learning of a grip task in both stroke and healthy individuals. To assess the use of tDCS over multiple days to promote motor learning of a grip task using a learning paradigm involving a speed-accuracy tradeoff in healthy individuals. In a double-blinded experiment, 30 right-handed subjects (mean age: 22.1±3.3 years) participated in the study and were randomly assigned to an anodal (n=15) or sham (n=15) stimulation group. First, subjects performed the grip task with their dominant hand while following the pace of a metronome. Afterwards, subjects trained on the task, at their own pace, over 5 consecutive days while receiving sham or anodal tDCS over M1. After training, subjects performed de novo the metronome-assisted task. The change in performance between the pre and post metronome-assisted task was used to assess the impact of the grip task and tDCS on learning. Anodal tDCS over M1 had a significant effect on the speed-accuracy tradeoff function. The anodal tDCS group showed significantly greater improvement in performance (39.28±15.92%) than the sham tDCS group (24.06±16.35%) on the metronome-assisted task, t(28)=2.583, P=0.015 (effect size d=0.94). Anodal tDCS is effective in promoting grip motor learning in healthy individuals. Further studies are warranted to test its potential use for the rehabilitation of fine motor skills in stroke patients. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Quad-copter UAV BLDC Motor Control: Linear v/s non-linear control maps

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Deep Parikh

2015-08-01

Full Text Available This paper presents some investigations and comparison of using linear versus non-linear static motor-control maps for the speed control of a BLDC (Brush Less Direct Current motors used in quad-copter UAV (Unmanned Aerial Vehicles. The motor-control map considered here is the inverse of the static map relating motor-speed output to motor-voltage input for a typical out-runner type Brushless DC Motors (BLDCM.  Traditionally, quad-copter BLDC motor speed control uses simple linear motor-control map defined by the motor-constant specification. However, practical BLDC motors show non-linear characteristic, particularly when operated across wide operating speed-range as is commonly required in quad-copter UAV flight operations. In this paper, our investigations to compare performance of linear versus non-linear motor-control maps are presented. The investigations cover simulation-based and experimental study of BLDC motor speed control systems for  quad-copter vehicle available. First the non-linear map relating rotor RPM to motor voltage for quad-copter BLDC motor is obtained experimentally using an optical speed encoder. The performance of the linear versus non-linear motor-control-maps for the speed control are studied. The investigations also cover study of time-responses for various standard test input-signals e.g. step, ramp and pulse inputs, applied as the reference speed-commands. Also, simple 2-degree of freedom test-bed is developed in our laboratory to help test the open-loop and closed-loop experimental investigations. The non-linear motor-control map is found to perform better in BLDC motor speed tracking control performance and thereby helping achieve better quad-copter roll-angle attitude control.

Relationships between academic performance, SES school type and perceptual-motor skills in first grade South African learners: NW-CHILD study.

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Pienaar, A E; Barhorst, R; Twisk, J W R

2014-05-01

Perceptual-motor skills contribute to a variety of basic learning skills associated with normal academic success. This study aimed to determine the relationship between academic performance and perceptual-motor skills in first grade South African learners and whether low SES (socio-economic status) school type plays a role in such a relationship. This cross-sectional study of the baseline measurements of the NW-CHILD longitudinal study included a stratified random sample of first grade learners (n = 812; 418 boys and 394 boys), with a mean age of 6.78 years ± 0.49 living in the North West Province (NW) of South Africa. The Beery-Buktenica Developmental Test of Visual-Motor Integration-4 (VMI) was used to assess visual-motor integration, visual perception and hand control while the Bruininks Oseretsky Test of Motor Proficiency, short form (BOT2-SF) assessed overall motor proficiency. Academic performance in math, reading and writing was assessed with the Mastery of Basic Learning Areas Questionnaire. Linear mixed models analysis was performed with spss to determine possible differences between the different VMI and BOT2-SF standard scores in different math, reading and writing mastery categories ranging from no mastery to outstanding mastery. A multinomial multilevel logistic regression analysis was performed to assess the relationship between a clustered score of academic performance and the different determinants. A strong relationship was established between academic performance and VMI, visual perception, hand control and motor proficiency with a significant relationship between a clustered academic performance score, visual-motor integration and visual perception. A negative association was established between low SES school types on academic performance, with a common perceptual motor foundation shared by all basic learning areas. Visual-motor integration, visual perception, hand control and motor proficiency are closely related to basic academic skills

Complete modeling of rotary ultrasonic motors actuated by traveling flexural waves

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Bao, Xiaoqi; Bar-Cohen, Yoseph

2000-06-01

Ultrasonic rotary motors have the potential to meet this NASA need and they are developed as actuators for miniature telerobotic applications. These motors are being adapted for operation at the harsh space environments that include cryogenic temperatures and vacuum and analytical tools for the design of efficient motors are being developed. A hybrid analytical model was developed to address a complete ultrasonic motor as a system. Included in this model is the influence of the rotor dynamics, which was determined experimentally to be important to the motor performance. The analysis employs a 3D finite element model to express the dynamic characteristics of the stator with piezoelectric elements and the rotor. The details of the stator including the teeth, piezoelectric ceramic, geometry, bonding layer, etc. are included to support practical USM designs. A brush model is used for the interface layer and Coulomb's law for the friction between the stator and the rotor. The theoretical predictions were corroborated experimentally for the motor. In parallel, efforts have been made to determine the thermal and vacuum performance of these motors. To explore telerobotic applications for USMs a robotic arm was constructed with such motors.

Development of common principles for the evaluation of quality characteristics of motor activity in the fitness and sports aerobics aesthetic orientation

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Galyna Artemyeva

2015-12-01

Full Text Available Purpose: to develop and validate methods for quantifying qualitative indicators special physical preparedness of sportsmen in fitness-aerobics and sports aesthetic orientation. Materials and Methods: an analytical synthesis of these scientific and methodical literature, the use of the theory of similarity and dimensionality, biomechanical analysis of motor activity, processing of video. Results: based on the use of similarity theory presents the methods of quantitative evaluation of qualitative characteristics of motor activity in special physical training, which allow an assessment of motor talent of the athlete and to provide objective guidance to training in particular sport. Conclusions: the presented methods quantify the qualitative indicators of the special motor preparation allow us to estimate a measure of motor gifted individual and his susceptibility to training in particular sport

Anthropometric Characteristics, Physical Fitness and Motor Coordination of 9 to 11 Year Old Children Participating in a Wide Range of Sports

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Elferink-Gemser, Marije; Hartman, Esther; Willemse, Bas; Philippaerts, Renaat; Visscher, Chris; Lenoir, Matthieu

2015-01-01

Objectives The aim of this study was to investigate to what extent 9 to 11 year old children participating in a specific sport already exhibit a specific anthropometric, physical fitness and motor coordination profile, in line with the requirements of that particular sport. In addition, the profiles in children with a different training volume were compared and possible differences in training hours per week between children from a low, moderate, and high level of physical fitness and motor coordination were investigated. Methods and Results Data of 620 children, 347 boys and 273 girls, who participated in the Flemish Sports Compass were used. Only the primary sport of each child was considered and six groups of sports (Ball sports, Dance, Gymnastics, Martial arts, Racquet sports and Swimming) were formed based on common characteristics. Measurements consisted of 17 tests. Independent T-tests and Mann-Whitney U-tests revealed few differences between the groups of sports and the discriminant analyses with the moderate and low active group did not show any significant results (p > .05). However, when discriminating among the high active children, a 85.2 % correct classification between six groups of sports was found (Wilks’ Λ = .137 and p sport per week (2.50 ± 1.84 hours) compared to the children performing best (3.25 ± 2.60 hours) (p = .016) and the children performing above average (2.90 ± 1.96 hours) (p = .029) on physical fitness and motor coordination. Discussion The study showed that in general, children at a young age do not exhibit sport-specific characteristics, except in children with a high training volume. It is possible that on the one hand, children have not spent enough time yet in their sport to develop sport-specific qualities. On the other hand, it could be possible that they do not take individual qualities into account when choosing a sport. PMID:25978313

Thermal performance of 2350 kW totally enclosed air to air cooled motor

Energy Technology Data Exchange (ETDEWEB)

Chang, C.C.; Kuo, S.C.; Chen, S.L. [National Taiwan Univ., Taipei, Taiwan (China). Dept. of Mechanical Engineering; Cheng, T.F. [TATUNG CO., Sanhsia, Taiwan (China)

2009-07-01

This study investigated numerically and experimentally the thermal performance of a 2350 kW enclosed air-to-air cooled motor. The experiment was divided into 2 sections. The centrifugal fans were tested using a standard test apparatus. Flow rates, output power, and pressure drop between the inlet and outlet were obtained. The motor was then tested to measure the flow rate of the external flow, and inlet and outlet temperatures of the external and internal flow in the heat exchanger. Motor performance was then simulated using a computational fluid dynamics (CFD) tool. Heat transfer within the motor was divided into external and internal flows. External flow was driven by the rotation of the centrifugal fan mounted to the frame on the motor shaft and passing through the tubes of a staggered heat exchanger mounted on the top of the frame. Internal flow was circulated through the heat exchanger by 2 axial fans located on either side of the rotor and cooled by the external flow. Axial and centrifugal fan simulations were in good agreement with results obtained during the experiments. The study demonstrated that the calculated velocity distributions of external flow fluids through the heat exchanger tubes are non-uniform. Air outlet temperatures for internal and external flows were estimated within 2 per cent. However, stator and rotor simulations were 3 per cent lower than experimental measured values. 7 refs., 1 tab., 15 figs.

The Determination of the Asynchronous Traction Motor Characteristics of Locomotive

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Pavel Grigorievich Kolpakhchyan

2017-01-01

Full Text Available The article deals with the problem of the locomotive asynchronous traction motor control with the AC diesel-electric transmission. The limitations of the torque of the traction motor when powered by the inverter are determined. The recommendations to improve the use of asynchronous traction motor of locomotives with the AC diesel-electric transmission are given.

A cycloidal wobble motor driven by shape memory alloy wires

International Nuclear Information System (INIS)

Hwang, Donghyun; Higuchi, Toshiro

2014-01-01

A cycloidal wobble motor driven by shape memory alloy (SMA) wires is proposed. In realizing a motor driving mechanism well known as a type of reduction system, a cycloidal gear mechanism is utilized. It facilitates the achievement of bidirectional continuous rotation with high-torque capability, based on its high efficiency and high reduction ratio. The applied driving mechanism consists of a pin/roller based annular gear as a wobbler, a cycloidal disc as a rotor, and crankshafts to guide the eccentric wobbling motion. The wobbling motion of the annular gear is generated by sequential activation of radially phase-symmetrically placed SMA wires. Consequently the cycloidal disc is rotated by rolling contact based cycloidal gearing between the wobbler and the rotor. In designing the proposed motor, thermomechanical characterization of an SMA wire biased by extension springs is experimentally performed. Then, a simplified geometric model for the motor is devised to conduct theoretical assessment of design parametric effects on structural features and working performance. With consideration of the results from parametric analysis, a functional prototype three-phase motor is fabricated to carry out experimental verification of working performance. The observed experimental results including output torque, rotational speed, bidirectional positioning characteristic, etc obviously demonstrate the practical applicability and potentiality of the wobble motor. (paper)

Working memory and fine motor skills predict early numeracy performance of children with cerebral palsy.

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Van Rooijen, Maaike; Verhoeven, Ludo; Steenbergen, Bert

2016-01-01

Early numeracy is an important precursor for arithmetic performance, academic proficiency, and work success. Besides their apparent motor difficulties, children with cerebral palsy (CP) often show additional cognitive disturbances. In this study, we examine whether working memory, non-verbal intelligence, linguistic skills, counting and fine motor skills are positively related to the early numeracy performance of 6-year-old children with CP. A total of 56 children (M = 6.0, SD = 0.61, 37 boys) from Dutch special education schools participated in this cross-sectional study. Of the total group, 81% of the children have the spastic type of CP (33% unilateral and 66% bilateral), 9% have been diagnosed as having diskinetic CP, 8% have been diagnosed as having spastic and diskinetic CP and 2% have been diagnosed as having a combination of diskinetic and atactic CP. The children completed standardized tests assessing early numeracy performance, working memory, non-verbal intelligence, sentence understanding and fine motor skills. In addition, an experimental task was administered to examine their basic counting performance. Structural equation modeling showed that working memory and fine motor skills were significantly related to the early numeracy performance of the children (β = .79 and p working memory and early numeracy (β = .57, p working memory for early numeracy performance in children with CP and they warrant further research into the efficacy of intervention programs aimed at working memory training.

Performance comparison of three-phase flux reversal permanent magnet motors in BLDC and BLAC operation mode

International Nuclear Information System (INIS)

Stumberger, B.; Stumberger, G.; Hadziselimovic, M.; Hamler, A.; Gorican, V.; Jesenik, M.; Trlep, M.

2008-01-01

The paper presents a comparison of torque capability and flux-weakening performance of three-phase flux reversal permanent magnet motors with surface and inset permanent magnets. Finite element analysis is employed to determine the performance of each motor in BLDC and BLAC operation mode. It is shown that the torque capability and flux-weakening performance of surface or inset permanent magnet configuration is strongly dependent on the stator teeth number/rotor pole number combination

The relationship of overweight and obesity to the motor performance ...

African Journals Online (AJOL)

2011-11-02

Nov 2, 2011 ... Objectives: This study aimed to determine the relationship between overweight and obesity and the motor performance of nine- to 13-year-old ... Body coordination is an indication of balance skills, as well as ..... who work with overweight and obese learners in these age .... statement: life skills grade 4-6.

Cardiorespiratory Fitness and Motor Skills in Relation to Cognition and Academic Performance in Children – A Review

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Haapala, Eero A.

2013-01-01

Different elements of physical fitness in children have shown a declining trend during the past few decades. Cardiorespiratory fitness and motor skills have been associated with cognition, but the magnitude of this association remains unknown. The purpose of this review is to provide an overview of the relationship of cardiorespiratory fitness and motor skills with cognitive functions and academic performance in children up to 13 years of age. Cross-sectional studies suggest that children with higher cardiorespiratory fitness have more efficient cognitive processing at the neuroelectric level, as well as larger hippocampal and basal ganglia volumes, compared to children with lower cardiorespiratory fitness. Higher cardiorespiratory fitness has been associated with better inhibitory control in tasks requiring rigorous attention allocation. Better motor skills have been related to more efficient cognitive functions including inhibitory control and working memory. Higher cardiorespiratory fitness and better motor skills have also been associated with better academic performance. Furthermore, none of the studies on cardiorespiratory fitness have revealed independent associations with cognitive functions by controlling for motor skills. Studies concerning the relationship between motor skills and cognitive functions also did not consider cardiorespiratory fitness in the analyses. The results of this review suggest that high levels of cardiorespiratory fitness and motor skills may be beneficial for cognitive development and academic performance but the evidence relies mainly on cross-sectional studies. PMID:23717355

Study on a high thrust force bi-double-sided permanent magnet linear synchronous motor

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Liang Tong

2016-03-01

Full Text Available A high thrust force bi-double-sided permanent magnet linear synchronous motor used in gantry-type five-axis machining center is designed and its performance was tested in this article. This motor is the subproject of Chinese National Science and Technology Major Project named as “development of domestic large thrust linear motor used in high-speed gantry-type five-axis machining center project” jointly participated by enterprises and universities. According to the requirement of the application environment and motor performance parameters, the linear motor’s basic dimensions, form of windings, and magnet arrangement are preliminarily specified through theoretical analysis and calculation. To verify the correctness of the result of the calculation, the finite element model of the motor is established. The static and dynamic characteristics of the motor are studied and analyzed through the finite element method, and the initial scheme is revised. The prototype of the motor is manufactured based on the final revised structure parameters, and the performance of the motor is fully tested using the evaluation platform for direct-drive motor component. Experimental test results meet the design requirements and show the effectiveness of design method and process.

Motor performance as predictor of physical activity in children - The CHAMPS Study-DK

DEFF Research Database (Denmark)

Larsen, Lisbeth Runge; Kristensen, Peter Lund; Junge, Tina

, health-related fitness and performance-related fitness were significantly associated to time spent at moderate to vigorous physical activity level at three years follow up. The clinical relevance of the results indicated cardiorespiratory fitness and shuttle run to be important skills to perceive......Background Physical activity is associated to several health benefits in children and has a tendency to track from childhood to adulthood. An adequate motor performance has been shown positively related to physical activity level in cross sectional studies and may be the foundation of a healthy...... lifestyle, but there is a lack of longitudinal studies. The objective of this study was to explore the longitudinal relationship between motor performance and physical activity in a three-year follow up study. Methods Longitudinal analyses were performed using data from the CHAMPS-Study DK, including 673...

Experimental Study of the Swirling Oxidizer Flow in HTPB/N2O Hybrid Rocket Motor

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Mohammad Mahdi Heydari

2017-01-01

Full Text Available Effects of swirling oxidizer flow on the performance of a HTPB/N2O Hybrid rocket motor were studied. A hybrid propulsion laboratory has been developed, to characterize internal ballistics characteristics of swirl flow hybrid motors and to define the operating parameters, like fuel regression rate, specific impulse, and characteristics velocity and combustion efficiency. Primitive variables, like pressure, thrust, temperature, and the oxidizer mass flow rate, were logged. A modular motor with 70 mm outer diameter and variable chamber length is designed for experimental analysis. The injector module has four tangential injectors and one axial injector. Liquid nitrous oxide (N2O as an oxidizer is injected at the head of combustion chamber into the motor. The feed system uses pressurized air as the pressurant. Two sets of tests have been performed. Some tests with axial and tangential oxidizer injection and a test with axial oxidizer injection were done. The test results show that the fuel grain regression rate has been improved by applying tangential oxidizer injection at the head of the motor. Besides, it was seen that combustion efficiency of motors with the swirl flow was about 10 percent more than motors with axial flow.

Motor performance is impaired following vestibular stimulation in ageing mice.

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Victoria W.K. Tung

2016-02-01

Full Text Available Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5-6, 8-9 and 27-28 months were tested using a combination of standard (such as grip strength and rotarod and newly-developed behavioural tests (including balance beam and walking trajectory tests with a vestibular stimulus. In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2-3 Hz and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip from the beam. Furthermore, aged mice (27-28 months that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13, and 27-28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13, and 27-28 months. Conclusion: This study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioural changes in task performance were observed.

Motor Performance is Impaired Following Vestibular Stimulation in Ageing Mice.

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Tung, Victoria W K; Burton, Thomas J; Quail, Stephanie L; Mathews, Miranda A; Camp, Aaron J

2016-01-01

Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5-6, 8-9 and 27-28 months were tested using a combination of standard (such as grip strength and rotarod) and newly-developed behavioral tests (including balance beam and walking trajectory tests with a vestibular stimulus). In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2-3 Hz) and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip (FS) from the beam. Furthermore, aged mice (27-28 months) that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13 and 27-28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13 and 27-28 months. this study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioral changes in task performance were observed.

Neuroplasticity & Motor Learning

DEFF Research Database (Denmark)

Jensen, Jesper Lundbye

Practice of a new motor task is usually associated with an improvement in performance. Indeed, if we stop practicing and return the next day to the same task, we find that our performance has been maintained and may even be better than it was at the start of the first day. This improvement...... is a measure of our ability to form and store a motor memory of the task. However, the initial memory of the task is labile and may be subject to interference. During and following motor learning plastic changes occur within the central nervous system. On one hand these changes are driven by motor practice......, on the other hand the changes underlie the formation of motor memory and the retention of improved motor performance. During motor learning changes may occur at many different levels within the central nervous system dependent on the type of task and training. Here, we demonstrate different studies from our...

Analysis on Bilateral Hindlimb Mapping in Motor Cortex of the Rat by an Intracortical Microstimulation Method

OpenAIRE

Seong, Han Yu; Cho, Ji Young; Choi, Byeong Sam; Min, Joong Kee; Kim, Yong Hwan; Roh, Sung Woo; Kim, Jeong Hoon; Jeon, Sang Ryong

2014-01-01

Intracortical microstimulation (ICMS) is a technique that was developed to derive movement representation of the motor cortex. Although rats are now commonly used in motor mapping studies, the precise characteristics of rat motor map, including symmetry and consistency across animals, and the possibility of repeated stimulation have not yet been established. We performed bilateral hindlimb mapping of motor cortex in six Sprague-Dawley rats using ICMS. ICMS was applied to the left and the righ...

Manipulating motor performance and memory through real-time fMRI neurofeedback

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Scharnowski, Frank; Veit, Ralf; Zopf, Regine; Studer, Petra; Bock, Simon; Diedrichsen, Jörn; Goebel, Rainer; Mathiak, Klaus; Birbaumer, Niels; Weiskopf, Nikolaus

2015-01-01

Task performance depends on ongoing brain activity which can be influenced by attention, arousal, or motivation. However, such modulating factors of cognitive efficiency are unspecific, can be difficult to control, and are not suitable to facilitate neural processing in a regionally specific manner. Here, we non-pharmacologically manipulated regionally specific brain activity using technically sophisticated real-time fMRI neurofeedback. This was accomplished by training participants to simultaneously control ongoing brain activity in circumscribed motor and memory-related brain areas, namely the supplementary motor area and the parahippocampal cortex. We found that learned voluntary control over these functionally distinct brain areas caused functionally specific behavioral effects, i.e. shortening of motor reaction times and specific interference with memory encoding. The neurofeedback approach goes beyond improving cognitive efficiency by unspecific psychological factors such as attention, arousal, or motivation. It allows for directly manipulating sustained activity of task-relevant brain regions in order to yield specific behavioral or cognitive effects. PMID:25796342

Differences in visuo-motor control in skilled vs. novice martial arts athletes during sustained and transient attention tasks: a motor-related cortical potential study.

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Sanchez-Lopez, Javier; Fernandez, Thalia; Silva-Pereyra, Juan; Martinez Mesa, Juan A; Di Russo, Francesco

2014-01-01

Cognitive and motor processes are essential for optimal athletic performance. Individuals trained in different skills and sports may have specialized cognitive abilities and motor strategies related to the characteristics of the activity and the effects of training and expertise. Most studies have investigated differences in motor-related cortical potential (MRCP) during self-paced tasks in athletes but not in stimulus-related tasks. The aim of the present study was to identify the differences in performance and MRCP between skilled and novice martial arts athletes during two different types of tasks: a sustained attention task and a transient attention task. Behavioral and electrophysiological data from twenty-two martial arts athletes were obtained while they performed a continuous performance task (CPT) to measure sustained attention and a cued continuous performance task (c-CPT) to measure transient attention. MRCP components were analyzed and compared between groups. Electrophysiological data in the CPT task indicated larger prefrontal positive activity and greater posterior negativity distribution prior to a motor response in the skilled athletes, while novices showed a significantly larger response-related P3 after a motor response in centro-parietal areas. A different effect occurred in the c-CPT task in which the novice athletes showed strong prefrontal positive activity before a motor response and a large response-related P3, while in skilled athletes, the prefrontal activity was absent. We propose that during the CPT, skilled athletes were able to allocate two different but related processes simultaneously according to CPT demand, which requires controlled attention and controlled motor responses. On the other hand, in the c-CPT, skilled athletes showed better cue facilitation, which permitted a major economy of resources and "automatic" or less controlled responses to relevant stimuli. In conclusion, the present data suggest that motor expertise

Motor skills and school performance in children with daily physical education in school--a 9-year intervention study.

Science.gov (United States)

Ericsson, I; Karlsson, M K

2014-04-01

The aim was to study long-term effects on motor skills and school performance of increased physical education (PE). All pupils born 1990-1992 from one school were included in a longitudinal study over nine years. An intervention group (n = 129) achieved daily PE (5 × 45 min/week) and if needed one extra lesson of adapted motor training. The control group (n = 91) had PE two lessons/week. Motor skills were evaluated by the Motor Skills Development as Ground for Learning observation checklist and school achievements by marks in Swedish, English, Mathematics, and PE and proportion of pupils who qualified for upper secondary school. In school year 9 there were motor skills deficits in 7% of pupils in the intervention group compared to 47% in the control group (P motor skills deficit than among pupils with motor skills deficits (P motor skills training during the compulsory school years is a feasible way to improve not only motor skills but also school performance and the proportion of pupils who qualify for upper secondary school. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Design of a Bearingless Outer Rotor Induction Motor

Directory of Open Access Journals (Sweden)

Yuxin Sun

2017-05-01

Full Text Available A bearingless induction (BI motor with an outer rotor for flywheel energy storage systems is proposed due to the perceived advantages of simple rotor structure, non-contact support and high speed operation. Firstly, the configuration and operation principle of the proposed motor are described. Then several leading dimensional parameters are optimally calculated for achieving the maximum average values and the minimum ripples of torque output and suspension force. Finally, by using the finite element method, the characteristics and performance of the proposed machine are analyzed and verified.

Assessing Energy Efficiency Opportunities in US Industrial and Commercial Building Motor Systems

Energy Technology Data Exchange (ETDEWEB)

Rao, Prakash; Sheaffer, Paul; McKane, Aimee; Scheihing, Paul

2015-09-01

In 2002, the United States Department of Energy (USDOE) published an energy efficiency assessment of U.S. industrial sector motor systems titled United States Industrial Electric Motor Systems Market Opportunities Assessment. The assessment advanced motor system efficiency by providing a greater understanding of the energy consumption, use characteristics, and energy efficiency improvement potential of industrial sector motor systems in the U.S. Since 2002, regulations such as Minimum Energy Performance Standards, cost reductions for motor system components such as variable frequency drives, system-integrated motor-driven equipment, and awareness programs for motor system energy efficiency have changed the landscape of U.S. motor system energy consumption. To capture the new landscape, the USDOE has initiated a three-year Motor System Market Assessment (MSMA), led by Lawrence Berkeley National Laboratory (LBNL). The MSMA will assess the energy consumption, operational and maintenance characteristics, and efficiency improvement opportunity of U.S. industrial sector and commercial building motor systems. As part of the MSMA, a significant effort is currently underway to conduct field assessments of motor systems from a sample of facilities representative of U.S. commercial and industrial motor system energy consumption. The Field Assessment Plan used for these assessments builds on recent LBNL research presented at EEMODS 2011 and EEMODS 2013 using methods for characterizing and determining regional motor system energy efficiency opportunities. This paper provides an update on the development and progress of the MSMA, focusing on the Field Assessment Plan and the framework for assessing the global supply chain for emerging motors and drive technologies.

Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development & Performance Analysis

Science.gov (United States)

Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan

2014-01-01

ATA-002 Technical Team has successfully designed, developed, tested and assessed the SLS Pathfinder propulsion systems for the Main Base Heating Test Program. Major Outcomes of the Pathfinder Test Program: Reach 90% of full-scale chamber pressure Achieved all engine/motor design parameter requirements Reach steady plume flow behavior in less than 35 msec Steady chamber pressure for 60 to 100 msec during engine/motor operation Similar model engine/motor performance to full-scale SLS system Mitigated nozzle throat and combustor thermal erosion Test data shows good agreement with numerical prediction codes Next phase of the ATA-002 Test Program Design & development of the SLS OML for the Main Base Heating Test Tweak BSRM design to optimize performance Tweak CS-REM design to increase robustness MSFC Aerosciences and CUBRC have the capability to develop sub-scale propulsion systems to meet desired performance requirements for short-duration testing.

Direct and Conceptual Replications of Burgmer & Englich (2012: Power May Have Little to No Effect on Motor Performance.

Directory of Open Access Journals (Sweden)

Margaret Cusack

Full Text Available Burgmer and Englich (2012 have reported that manipulating feelings of power can substantially improve performance on two motor tasks: golf and darts. We conducted two high-powered direct replications of the effects of power on golf, two online conceptual replications using mirror-tracing as a performance measure, and an additional conceptual replication using a cognitive performance measure (word-search. Overall, we found little to no effect of power on motor skill (d = 0.09, 95% CI[-0.07, 0.22], n = 603. We varied task difficulty, re-analyzed data without participants showing weak responses on manipulation checks, and tried adjusting performance scores for age, gender, and initial task skill. None of these secondary analyses revealed a strong effect of power on performance. A meta-analysis integrating our data with Burgmer & Englich leaves open the possibility that manipulating power could provide a modest boost in motor skill (d = 0.19, 95% CI [0.001, 0.38], n = 685. Unfortunately, the pattern of performance changes we observed was unrelated to group differences in perceived and rated power, suggesting that what motor effects do occur with this protocol may not be directly related to the construct of power. [Burgmer, P., &Englich, B. (2012. Bullseye!: How Power Improves Motor Performance. Social Psychological and Personality Science, 4(2, 224-232.].

Behavior of high efficiency electric motors; Comportamiento de motores electricos de alta eficiencia

Energy Technology Data Exchange (ETDEWEB)

Bonett, Austin H. [IEEE, (United States)

2001-09-01

The energy efficiency is one of the main parameters in the design of the industrial motors of general purpose; nevertheless, it is avoided that it is at the cost of the reliability or to the global performance of the motor. Exist user groups of this equipment that consider that, in the search of a greater efficiency, the useful life period is diminished and the characteristics of operation of the motor are affected. During the past last years, the author has studied the aspects of quality and reliability, as well as the operative advantages of the high efficiency motors and written down the increasing interest for these aspects. Also he has detected that a great number of users has realized that, additionally to the obvious energy saving, the efficient motor offers a greater reliability and a longer useful life in most of the industrial applications. The objective of this article is to present the differences in the quality levels, reliability and operation parameters of high efficiency squirrel cage type electrical motors with those of the motors of standard manufacture. [Spanish] La eficiencia energetica es uno de los principales parametros en el diseno de los motores industriales de proposito general; sin embargo, se evita que sea a costa de la confiabilidad o del desempeno global del motor. Existen grupos de usuarios de estos equipos que consideran que, en la busqueda de una mayor eficiencia, se disminuye el periodo de vida util y se afectan las caracteristicas de operacion del motor. Durante los ultimos anos, el autor ha estudiado los aspectos de calidad y confiabilidad, asi como las ventajas operativas de los motores de alta eficiencia y anotado el incremento del interes por estos aspectos. Tambien ha detectado que un gran numero de usuarios se ha dado cuenta que, adicionalmente a los obvios ahorros de energia, el motor eficiente ofrece una mayor confiabilidad y una vida util mas larga en la mayoria de las aplicaciones industriales. El objetivo de este

Interventions to improve gross motor performance in children with neurodevelopmental disorders: a meta-analysis.

Science.gov (United States)

Lucas, Barbara R; Elliott, Elizabeth J; Coggan, Sarah; Pinto, Rafael Z; Jirikowic, Tracy; McCoy, Sarah Westcott; Latimer, Jane

2016-11-29

Gross motor skills are fundamental to childhood development. The effectiveness of current physical therapy options for children with mild to moderate gross motor disorders is unknown. The aim of this study was to systematically review the literature to investigate the effectiveness of conservative interventions to improve gross motor performance in children with a range of neurodevelopmental disorders. A systematic review with meta-analysis was conducted. MEDLINE, EMBASE, AMED, CINAHL, PsycINFO, PEDro, Cochrane Collaboration, Google Scholar databases and clinical trial registries were searched. Published randomised controlled trials including children 3 to ≤18 years with (i) Developmental Coordination Disorder (DCD) or Cerebral Palsy (CP) (Gross Motor Function Classification System Level 1) or Developmental Delay or Minimal Acquired Brain Injury or Prematurity (gross motor outcomes obtained using a standardised assessment tool. Meta-analysis was performed to determine the pooled effect of intervention on gross motor function. Methodological quality and strength of meta-analysis recommendations were evaluated using PEDro and the GRADE approach respectively. Of 2513 papers, 9 met inclusion criteria including children with CP (n = 2) or DCD (n = 7) receiving 11 different interventions. Only two of 9 trials showed an effect for treatment. Using the least conservative trial outcomes a large beneficial effect of intervention was shown (SMD:-0.8; 95% CI:-1.1 to -0.5) with "very low quality" GRADE ratings. Using the most conservative trial outcomes there is no treatment effect (SMD:-0.1; 95% CI:-0.3 to 0.2) with "low quality" GRADE ratings. Study limitations included the small number and poor quality of the available trials. Although we found that some interventions with a task-orientated framework can improve gross motor outcomes in children with DCD or CP, these findings are limited by the very low quality of the available evidence. High quality intervention

The cognitive complexity of concurrent cognitive-motor tasks reveals age-related deficits in motor performance

DEFF Research Database (Denmark)

Oliveira, Anderson Souza; Reiche, Mikkel Staall; Vinescu, Cristina Ioana

2018-01-01

Aging reduces cognitive functions, and such impairments have implications in mental and motor performance. Cognitive function has been recently linked to the risk of falls in older adults. Physical activities have been used to attenuate the declines in cognitive functions and reduce fall incidence......, but little is known whether a physically active lifestyle can maintain physical performance under cognitively demanding conditions. The aim of this study was to verify whether physically active older adults present similar performance deficits during upper limb response time and precision stepping walking...... tasks when compared to younger adults. Both upper limb and walking tasks involved simple and complex cognitive demands through decision-making. For both tasks, decision-making was assessed by including a distracting factor to the execution. The results showed that older adults were substantially slower...

Motor performance and functional ability in preschool- and early school-aged children with Juvenile Idiopathic Arthritis: a cross-sectional study

Directory of Open Access Journals (Sweden)

Takken Tim

2008-01-01