Добірка наукової літератури з теми "Time and speed of a single movement"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Time and speed of a single movement".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Time and speed of a single movement"
1
Flanders, M., and U. Herrmann. "Two components of muscle activation: scaling with the speed of arm movement." Journal of Neurophysiology 67, no. 4 (April 1, 1992): 931–43. http://dx.doi.org/10.1152/jn.1992.67.4.931.
Повний текст джерелаАнотація:
1. The temporal waveform of muscle activity was related to the speed of arm movement. Speed was expressed in terms of the duration of a fixed amplitude movement or the "movement time." 2. Human subjects moved their arms to targets in three-dimensional space. The right arm started at a standard initial position and moved directly to the target in a single stroke. The targets were placed in various directions in a vertical plane. The arm movements consisted of shoulder and elbow rotations. 3. Subjects were required to vary the speed of their movements. In most of the experiments, trials with different movement times were randomly ordered. One of the experiments also included randomly interspersed static trials, in which the subject held the arm still at the initial posture, the final posture, or halfway between the two extremes. 4. Electromyographic (EMG) activity was recorded from several superficial elbow and/or shoulder muscles. The time base of rectified EMG records was normalized for movement time such that records from movements with various speeds were compressed to align the ending times of the movements. 5. A principal component (PC) analysis revealed that the compressed EMG waveforms could be described by a summation of PC1 and PC2 waveforms; each individual EMG waveform was approximated by a weighted sum of these two components. 6. The PC1 weighting coefficients scaled down in a monotonic relationship with movement time such that the fastest movement corresponded to a large positive weighting coefficient and the slowest movement corresponded to a small positive weighting coefficient. The PC2 weighting coefficients exhibited a similar monotonic scaling, but the values ranged from positive to negative. Further analysis demonstrated that these two components can be mathematically transformed into a tonic waveform with a constant mathematically transformed into a tonic waveform with a constant weighting coefficient and a phasic waveform with positive weighting coefficients that scale down with movement time. 7. The amplitude scaling of EMG records cannot be described by a single component, but instead requires a summation of two separate components. The tonic component may correspond to the force element needed to counteract gravity, because the magnitude of this element does not scale with movement speed. The phasic component may correspond to the force element that scales quadratically to produce a linear increase in velocity.
2
Corcos, D. M., G. L. Gottlieb, and G. C. Agarwal. "Organizing principles for single-joint movements. II. A speed-sensitive strategy." Journal of Neurophysiology 62, no. 2 (August 1, 1989): 358–68. http://dx.doi.org/10.1152/jn.1989.62.2.358.
Повний текст джерелаАнотація:
1. Normal human subjects made discrete flexions of the elbow over a fixed distance in the horizontal plane from a stationary initial position to a visually defined target. We measured joint angle, acceleration, and electromyograms (EMGs) from two agonist and two antagonist muscles. 2. Changes in movement speed were elicited either by explicit instruction to the subject or by adjusting the target width. Instructions always required accurately stopping in the target zone. 3. Peak inertial torques and accelerations, movement times, and integrated EMGs were all highly correlated with speed. We show that inertial torque can be used as a linking variable that is almost sufficient to explain all correlations between the task, the EMG, and movement kinematics. 4. When subjects perform tasks that require control of movement speed, they adjust the rate at which torque is developed by the muscles. This rate is modulated by the way in which the muscles are activated. The rate at which joint torque develops is correlated with the rate at which the agonist EMG rises as well as with integrated EMG. 5. The antagonist EMG shows two components. The latency of the first is 30-50 ms and independent of movement dynamics. The latency of the second component is proportional to movement time. The rate of rise and area of both components scale with torque. 6. We propose organizing principles for the control of single-joint movements in which tasks are performed by one of two strategies. These are called speed-insensitive and speed-sensitive strategies. 7. A model is proposed in which movements made under a speed-sensitive strategy are executed by controlling the intensity of an excitation pulse delivered to the motoneuron pool. The effect is to regulate the rate at which joint torque, and consequently acceleration, increases. 8. Movements of variable distance, speed, accuracy, and load are shown to be controlled by one of two consistent sets of rules for muscle activation. These rules apply to the control of both the agonist and antagonist muscles. Rules of activation lead to distinguishable patterns of EMG and torque development. All observable changes in movement kinematics are explained as deterministic consequences of these effects.
3
d'Avella, Andrea, Laure Fernandez, Alessandro Portone, and Francesco Lacquaniti. "Modulation of Phasic and Tonic Muscle Synergies With Reaching Direction and Speed." Journal of Neurophysiology 100, no. 3 (September 2008): 1433–54. http://dx.doi.org/10.1152/jn.01377.2007.
Повний текст джерелаАнотація:
How the CNS masters the many degrees of freedom of the musculoskeletal system to control goal-directed movements is a long-standing question. We have recently provided support to the hypothesis that the CNS relies on a modular control architecture by showing that the phasic muscle patterns for fast reaching movements in different directions are generated by combinations of a few time-varying muscle synergies: coordinated recruitment of groups of muscles with specific activation profiles. However, natural reaching movements occur at different speeds and require the control of both movement and posture. Thus we have investigated whether muscle synergies also underlie reaching at different speeds as well as the maintenance of stable arm postures. Hand kinematics and shoulder and elbow muscle surface EMGs were recorded in five subjects during reaches to eight targets in the frontal plane at different speeds. We found that the amplitude modulation of three time-invariant synergies captured the variations in the postural muscle patterns at the end of the movement. During movement, three phasic and three tonic time-varying synergies could reconstruct the time-normalized muscle pattern in all conditions. Phasic synergies were modulated in both amplitude and timing by direction and speed. Tonic synergies were modulated only in amplitude by direction. The directional tuning of both types of synergies was well described by a single or a double cosine function. These results suggest that muscle synergies are basic control modules that allow generating the appropriate muscle patterns through simple modulation and combination rules.
4
Herfst, Lucas J., and Michael Brecht. "Whisker Movements Evoked by Stimulation of Single Motor Neurons in the Facial Nucleus of the Rat." Journal of Neurophysiology 99, no. 6 (June 2008): 2821–32. http://dx.doi.org/10.1152/jn.01014.2007.
Повний текст джерелаАнотація:
The lateral facial nucleus is the sole output structure whose neuronal activity leads to whisker movements. To understand how single facial nucleus neurons contribute to whisker movement we combined single-cell stimulation and high-precision whisker tracking. Half of the 44 stimulated neurons gave rise to fast whisker protraction or retraction movement, whereas no stimulation-evoked movements could be detected for the remainder. Direction, speed, and amplitude of evoked movements varied across neurons. Protraction movements were more common than retraction movements ( n = 16 vs. n = 4), had larger amplitudes (1.8 vs. 0.3° for single spike events), and most protraction movements involved only a single whisker, whereas most retraction movements involved multiple whiskers. We found a large range in the amplitude of single spike-evoked whisker movements (0.06–5.6°). Onset of the movement occurred at 7.6 (SD 2.5) ms after the spike and the time to peak deflection was 18.2 (SD 4.3) ms. Each spike reliably evoked a stereotyped movement. In two of five cases peak whisker deflection resulting from consecutive spikes was larger than expected when based on linear summation of single spike-evoked movement profiles. Our data suggest the following coding scheme for whisker movements in the facial nucleus. 1) Evoked movement characteristics depend on the identity of the stimulated neuron (a labeled line code). 2) The facial nucleus neurons are heterogeneous with respect to the movement properties they encode. 3) Facial nucleus spikes are translated in a one-to-one manner into whisker movements.
5
Gottlieb, Gerald L., Daniel M. Corcos, and Gyan C. Agarwal. "Strategies for the control of voluntary movements with one mechanical degree of freedom." Behavioral and Brain Sciences 12, no. 2 (June 1989): 189–210. http://dx.doi.org/10.1017/s0140525x00048238.
Повний текст джерелаАнотація:
AbstractA theory is presented to explain how accurate, single-joint movements are controlled. The theory applies to movements across different distances, with different inertial loads, toward targets of different widths over a wide range of experimentally manipulated velocities. The theory is based on three propositions. (1) Movements are planned according to “strategies” of which there are at least two: a speed-insensitive (SI) and a speed-sensitive (SS) one. (2) These strategies can be equated with sets of rules for performing diverse movement tasks. The choice between SI and SS depends on whether movement speed and/or movement time (and hence appropriate muscle forces) must be constrained to meet task requirements. (3) The electromyogram can be interpreted as a low-pass filtered version of the controlling signal to the motoneuron pools. This controlling signal can be modelled as a rectangular excitation pulse in which modulation occurs in either pulse amplitude or pulse width. Movements to different distances and with loads are controlled by the SI strategy, which modulates pulse width. Movements in which speed must be explicitly regulated are controlled by the SS strategy, which modulates pulse amplitude. The distinction between the two movement strategies reconciles many apparent conflicts in the motor control literature.
6
Gottlieb, G. L., D. M. Corcos, and G. C. Agarwal. "Organizing principles for single-joint movements. I. A speed-insensitive strategy." Journal of Neurophysiology 62, no. 2 (August 1, 1989): 342–57. http://dx.doi.org/10.1152/jn.1989.62.2.342.
Повний текст джерелаАнотація:
1. Normal human subjects made discrete elbow flexions and extensions in the horizontal plane from a stationary initial position to visually defined targets at different distances with a constant inertial load or made flexions to a visually defined target with different inertial loads. We measured joint angle, acceleration, and electromyograms (EMGs) from two agonist and two antagonist muscles. 2. Subjects were instructed to move their limbs accurately but quickly to the targets. Movements of greater distances or lesser loads were performed at higher velocities. 3. Peak inertial torque, acceleration and velocity, movement time, and integrated, rectified EMG were all highly correlated with the task variables, distance and inertial load. We show that peak inertial torque can be used as a linking variable that is almost sufficient to explain all correlations between the tasks, the EMG, and movement kinematics. 4. The rate at which subjects initially developed torque to accelerate their movements was invariant over changes in the value of either task variable. The rising phase of the agonist EMG was also independent of the distance or load moved. 5. Two components were distinguished in the antagonist EMG. The first had a relatively constant latency and amplitude. It terminated on the onset of the second and larger component at a latency that was delayed as both distance and load increased. 6. The integrated, rectified antagonist EMG was proportional to inertial load and peak decelerating torque for changes in inertial load. When target distance varied, proportionality between peak decelerating torque and antagonist EMG could be found if correction was made for the effects of muscle length on the torque-EMG relationship. 7. We propose organizing principles for the control of single-joint human movements in which tasks are performed by one of two strategies. These are called speed-insensitive and speed-sensitive strategies. 8. A model is described in which movements made under a speed-insensitive strategy are executed by controlling the duration and the relative timing of amplitude invariant patterns of activation to the spinal motoneuron pools.
7
Filimonikhin, Gennadiy, Vladimir Pirogov, Maksim Hodunko, Ruslan Kisilov, and Vitalii Mazhara. "The dynamics of a resonance single-mass vibratory machine with a vibration exciter of targeted action that operates on the Sommerfeld effect." Eastern-European Journal of Enterprise Technologies 3, no. 7 (111) (June 17, 2021): 51–58. http://dx.doi.org/10.15587/1729-4061.2021.233960.
Повний текст джерелаАнотація:
This paper reports a study into the dynamics of a vibratory machine composed of a viscoelastically-fixed platform that can move vertically and two identical inertial vibration exciters. The vibration exciters' bodies rotate at the same angular velocities in opposite directions. The bodies host a single load in the form of a ball, roller, or pendulum. The loads' centers of mass can move relative to the bodies in a circle with a center on the axis of rotation. The loads' relative movements are hindered by the forces of viscous resistance. It was established that a vibratory machine theoretically possesses the following: – one to three oscillatory modes of movement under which loads get stuck at almost constant angular velocity and generate total unbalanced mass in the vertical direction only; – a no-oscillation mode under which loads rotate synchronously with the bodies and generate total unbalanced mass in the horizontal direction only. At the same time, only one oscillatory mode is resonant and exists at the above-the-resonance speeds of body rotation, lower than some characteristic speed. At the bodies' rotation speeds: ‒ pre-resonant; there is a globally asymptotically stable (the only existing) mode of load jams; ‒ above-the-resonance, lower than the characteristic velocity; there are locally asymptotically stable regimes ‒ both the resonance mode of movement of a vibratory machine and a no-oscillations mode; ‒ exceeding the characteristic velocity: there is a globally asymptotically stable no-oscillations mode. Computational experiments have confirmed the results of theoretical research. At the same time, it was additionally established that it would suffice, to enter a resonant mode of movement, to slowly accelerate the bodies of vibration exciters to the above-the-resonance speed, less than the characteristic speed. The results reported here could be interesting both for the theory and practice of designing new vibratory machines
8
Prosen, Jerneja, Nic James, Lygeri Dimitriou, Janez Perš, and Goran Vučković. "A Time-Motion Analysis of Turns Performed by Highly Ranked Viennese Waltz Dancers." Journal of Human Kinetics 37, no. 1 (June 1, 2013): 55–62. http://dx.doi.org/10.2478/hukin-2013-0025.
Повний текст джерелаАнотація:
Twenty-four dance couples performing at the 2011 IDSF (International DanceSport Federation) International Slovenia Open were divided into two groups: the first twelve placed couples (top ranked) and the last twelve placed couples (lower ranked). Video recordings were processed automatically using computer vision tracking algorithms under operator supervision to calculate movement parameters. Time and speed of movement were analysed during single natural (right) and reverse (left) turns performed during the Viennese waltz. Both top and lower ranked dancers tended to perform similar proportionate frequencies of reverse (≈ 35%) and natural (≈ 65%) turns. Analysis of reverse turns showed that the top ranked dancers performed less turns on a curved trajectory (16%) than the lower ranked dancers (33%). The top ranked couples performed all turns at similar speeds (F = 1.31, df = 3, p = 0.27; mean = 2.09m/s) all of which were significantly quicker than the lower ranked couples (mean = 1.94m/s), the greatest differences found for reverse turns (12.43% faster for curved trajectories, 8.42% for straight trajectories). This suggests that the ability to maintain a high speed in the more difficult turns, particularly the reverse turns on a curved trajectory, results in the overall dance appearing more fluent as the speed of movement does not fluctuate as much. This aspect of performance needs to be improved by lower ranked dancers if they wish to improve rating of their performance. Future research should determine which factors relate to the speed of turns.
9
Gribble, Paul L., David J. Ostry, Vittorio Sanguineti, and Rafael Laboissière. "Are Complex Control Signals Required for Human Arm Movement?" Journal of Neurophysiology 79, no. 3 (March 1, 1998): 1409–24. http://dx.doi.org/10.1152/jn.1998.79.3.1409.
Повний текст джерелаАнотація:
Gribble, Paul L., David J. Ostry, Vittorio Sanguineti, and Rafael Laboissière. Are complex control signals required for human arm movement? J. Neurophysiol. 79: 1409–1424, 1998. It has been proposed that the control signals underlying voluntary human arm movement have a “complex” nonmonotonic time-varying form, and a number of empirical findings have been offered in support of this idea. In this paper, we address three such findings using a model of two-joint arm motion based on the λ version of the equilibrium-point hypothesis. The model includes six one- and two-joint muscles, reflexes, modeled control signals, muscle properties, and limb dynamics. First, we address the claim that “complex” equilibrium trajectories are required to account for nonmonotonic joint impedance patterns observed during multijoint movement. Using constant-rate shifts in the neurally specified equilibrium of the limb and constant cocontraction commands, we obtain patterns of predicted joint stiffness during simulated multijoint movements that match the nonmonotonic patterns reported empirically. We then use the algorithm proposed by Gomi and Kawato to compute a hypothetical equilibrium trajectory from simulated stiffness, viscosity, and limb kinematics. Like that reported by Gomi and Kawato, the resulting trajectory was nonmonotonic, first leading then lagging the position of the limb. Second, we address the claim that high levels of stiffness are required to generate rapid single-joint movements when simple equilibrium shifts are used. We compare empirical measurements of stiffness during rapid single-joint movements with the predicted stiffness of movements generated using constant-rate equilibrium shifts and constant cocontraction commands. Single-joint movements are simulated at a number of speeds, and the procedure used by Bennett to estimate stiffness is followed. We show that when the magnitude of the cocontraction command is scaled in proportion to movement speed, simulated joint stiffness varies with movement speed in a manner comparable with that reported by Bennett. Third, we address the related claim that nonmonotonic equilibrium shifts are required to generate rapid single-joint movements. Using constant-rate equilibrium shifts and constant cocontraction commands, rapid single-joint movements are simulated in the presence of external torques. We use the procedure reported by Latash and Gottlieb to compute hypothetical equilibrium trajectories from simulated torque and angle measurements during movement. As in Latash and Gottlieb, a nonmonotonic function is obtained even though the control signals used in the simulations are constant-rate changes in the equilibrium position of the limb. Differences between the “simple” equilibrium trajectory proposed in the present paper and those that are derived from the procedures used by Gomi and Kawato and Latash and Gottlieb arise from their use of simplified models of force generation.
10
Cooper, Jr., William. "Foraging movements by the ambush-foraging striped plateau lizard (Sceloporus virgatus) vary between sexes and with air temperature, but not with distance to an immobile observer or time of day." Amphibia-Reptilia 32, no. 2 (2011): 203–12. http://dx.doi.org/10.1163/017353711x557014.
Повний текст джерелаАнотація:
AbstractLizard foraging activity is assessed quantitatively by measuring various aspects of activity including number of movements per minute (MPM), proportion of time spent moving (PTM), average speed over an observation period (AS), and speed while moving (MS). With some exceptions, single estimates are given without considering possible effects of environmental variables such as air temperature and time of day. Effects of distance between lizard and observer during observation, the standing distance, have not been studied previously. I measured foraging movements in a phrynosomatid ambush forager, Sceloporus virgatus, early in the breeding season to examine possible effects of sex, air temperature, time of day, and standing distance. Males had higher values of all four foraging movement variables than females. The major cause of this difference is presumably greater socially motivated movement by males, which have much larger home ranges than females. Decreased female foraging probably contributed to the difference because gravid and possibly late vitellogenic females reduce feeding and might become less mobile to reduce the likelihood of being detected by predators when a heavy clutch reduces running speed. Time of day and standing distance did not affect foraging movements. MPM, PTM, and AS decreased as temperature increased, but these effects were small. All pairs of MPM, PTM, and AS were positively correlated, but MS was correlated only with AS, and weakly. I discuss reasons for intraspecific and interspecific correlations among movement variables.
Дисертації з теми "Time and speed of a single movement"
1
Magaro, Christopher Michael. "Dissociating clock speed and attention in the modality effect." Click here for download, 2008. http://proquest.umi.com/pqdweb?did=1490081061&sid=1&Fmt=2&clientId=3260&RQT=309&VName=PQD.
Повний текст джерела
2
Pihnastyi, O. M., and R. O. Korsun. "Single-node model of the conveyor line with a constant speed movement of subjects of labor." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/42513.
Повний текст джерела
3
Gokbulut, Alev. "Monorail: An Alternative Transportation Mode For Metu." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1252667/index.pdf.
Повний текст джерелаАнотація:
The aim of this thesis is to investigate an alternative mode of transportation for METU and the impacts of spatial transformations generated by the proposed system in an
architectural context. This study embraces modern concepts of space-time in the practice of architectural design, and involves a sensitive consideration of the perception of space
relative to position, speed and movement. In an urban context, the thesis unfolds spatial transformations affected by new movement technology. While the notions of movement
and speed fundamentally shape the image of the contemporary city, METU campus will be reanalyzed within this framework.
4
Andrijauskaitė, Inga. "Kariūnų psichomotorinių procesų tyrimas ir įvertinimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060522_123126-98072.
Повний текст джерелаАнотація:
This Master Thesis involves the analysis and evaluation of military students psychomotor processes. This was carried out using the analyzer DPA – 1. This device is used for measuring dynamic parameters of independent or coordinated arm and leg movements by reacting to the target with a variety of geometric, colour or time parameters appearing on the screen. The DPA – 1 device enables scientists to analyse psychomotor reaction and dynamic and kinematical characteristics. The goal of the research was to identify the peculiarities of psychomotor reaction performing movements with the right and left arms. The participants of the research were 40 students (n=40) of the Lithuanian Military academy. Their age was 22.03 ± 0.54 years, body mass – 76.04 ± 9.13 kg, height – 180.29 ± 7.99 cm. Their right arm was dominant.
To achieve this goal the following tasks had to be completed:
1. To determine the differences in psychomotor reaction by performing the moves with the dominant and non-dominant arms.
2. To determine the difference between movement speed and accuracy by performing the movement with the right and the left arms.
3. To determine the connection between the parameters of psychomotor reaction of the right and the left arms.
The hypothesis:
We think that movements performed with the dominant arm have better psychomotor qualities.
The research methods:
1. Analysis of the scientific literature resources
2. Testing
3. Mathematical statistics
Conclusions
1. There were no... [to full text]
5
Chon, John H. "Characterization of single-cell movement using a computer-aided fluorescence time-lapse videomicroscopy system : role of integrins in endothelial cell migration." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/11171.
Повний текст джерела
6
Hajj, Joëlle. "Perceptual Ability is Diminished at Peak Limb Velocity of a Goal-directed Movement But is Unaffected During Motor Preparation." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36577.
Повний текст джерелаАнотація:
Due to various shortcomings of the visual system, some visual stimuli can only be identified with 100% accuracy if they are shown for a certain amount of time. This time can be measured using the Inspection Time (IT) paradigm. In an IT task, a “pi” figure with differing leg lengths is typically presented briefly (e.g., 20-200 ms) and is then immediately masked to prevent retinal afterimages. Participants are subsequently required to choose which of the two legs was longer. The objective of this task is to determine the shortest amount of time the pi figure needs to be shown for it to be perceived with 80% accuracy. Given that visual processing has been shown to
be altered during and /or prior to a movement, the present experiment sought to test how the requirement to perform a motor task affected IT. Twenty-eight participants took part in the experiment, which was comprised of three conditions: no-movement (NM), peak velocity (PV), and foreperiod (FP). In the NM condition, participants grasped a manipulandum and engaged in the IT paradigm. At the end of every trial, participants verbally stated which leg they believed was longest. In the PV condition participants made a rapid movement to a target, and the IT stimulus was presented when their limb reached peak velocity. Finally in the FP condition the IT stimulus was presented during foreperiod (FP). In all three conditions the IT stimulus was randomly presented from between 15-105 ms (in 15 ms increments) and masked for 400 ms. Results showed no significant differences on the IT task between the NM and FP conditions, suggesting no visual upregulation during foreperiod. However, IT performance was significantly
poorer in the PV condition in comparison to both the NM and FP condition, suggesting a visual downregulation at that particular movement kinematic.
7
Zaicevaitė, Vitalija. "Kojų judesių valdymo atsigavimas persirgus galvos smegenų insultu." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100526_133534-42399.
Повний текст джерелаАнотація:
Tyrimo objektas: kojų judesių reakcijos laiko bei judesių atlikimo greičio vertinimas.
Tyrimo problema: daugumai žmonių po insulto stebimas kojų judesių valdymo sutrikimas. Sutrikęs kojų judesių valdymas padidina griuvimų riziką, sutrikdo eiseną, apsunkina kasdieninę veiklą, riboja fizinį aktyvumą. Žmogaus rankų bei kojų dinaminių parametrų analizatoriaus DPA-1 pagalba galima tirti psichomotorinę reakciją, judesių dinamines bei kinematines charakteristikas, o tai suteikia didesnes galimybes įvertinti insulto liekamųjų reiškinių poveikį kojų judesių valdymui.
Tyrimo tikslas: nustatyti kojų judesių valdymo atsigavimą persirgus galvos smegenų insultu.
Tyrimo metodai ir organizavimas: tyrimas buvo atliekamas Lietuvos kūno kultūros akademijoje (LKKA) Žmogaus motorikos laboratorijoje 2009 – 2010 metais. Tiriamųjų kontingentą sudarė dvi grupės: tiriamoji ir kontrolinė. Tiriamąją grupę sudarė 10 žmonių patyrusių galvos smegenų insultą, amžiaus vidurkis: 70,1 ± 1,3 metai. Kontrolinę grupę sudarė 10 vyresnio amžiaus, neurologinių sutrikimų neturinčių žmonių, amžiaus vidurkis: 66,6 ± 1,8 metai. Kojų dinaminių judesių tyrimui buvo naudojamas LKKA mokslininkų ir UAB „Katra“ specialistų sukurtas originalus prietaisas - žmogaus rankų ir kojų judesių dinaminių parametrų analizatorius DPA-1. Tyrimo metu buvo registruojamas dešinės ir kairės kojos judesių reakcijos laikas (RT) bei dešinės ir kairės kojos maksimalus judesių greitis (V ) atliekant reakcijos, greitumo ir tikslumo užduotis... [toliau žr. visą tekstą]Problem of study: lots of people feel disorder of controlling legs dynamic movement after stroke. Disordered control of legs movement rise the risk of fallings, unbalances gait, prejudice casual activity, limits physical activity. With help of human hands and legs dynamic parameter analyzer (DPA-1) it is possible to feel psychomotorical reaction, movements dynamic and kinematic characteristics, and this gives better opportunities to value remanant stroke influence for control of legs dynamic movement. Object of study: evaluation of legs movement reaction time and speed of movement performance. Aim of study: to determine recovery of legs motor control after stroke. Methods and organization of sudy: this research was carried out in the Laboratory of Human motor control at the Lithuanian Academy of physical Education (LAPE) during 2009 - 2010. Investigative contingent included two groups: trial and control. In trial group there were included 10 people, who had a stroke of head brains. Average of age - 70±3 years. In control group there were included 10 older people without neurological disorder. Average of age - 60±3 years. For legs dynamic movement research was used new original gear made by LAPE scientists and company “Katra” – human hands and legs dynamic parameter analyser DPA-1. During research there was registering the reaction time (RT) of right and left leg and the maximal movement speed (V ) of right and left leg performing tasks of reaction, speed and accuracy. Goals... [to full text]
8
Гетманцев, С. В., А. С. Яцунский, О. В. Кувалдина, И. В. Колоскова, А. А. Раевский, И. Н. Веселова, S. V. Getmantsev та ін. "Исследование уровня физического качества быстроты". Thesis, 2016. http://eir.nuos.edu.ua/xmlui/handle/123456789/4635.
Повний текст джерелаАнотація:
Исследование уровня физического качества быстроты / С. В.Гетманцев, А. С. Яцунский, О. В. Кувалдина, И. В. Колоскова, А. А. Раевский, И. Н. Веселова // Матеріали XVI всеукр. наук.-практ. конф. "Медико-біологічні проблеми фізичної культури, спорту та здоров’я людини". – Миколаїв : МНУ ім. В. О. Сухомлинського, 2016. – Вип. 16. – С. 55–59.Determine the pace, time and speed of a single movement, the frequency of motor actions, time of sensorimotor responses to auditory and visual stimuli in athletes 17-18 years engaged in rowing. We have developed a method of determining the effect of coaching activities modeled passing distance in rowing: the first period - starting acceleration, the second - to maintain optimum speed at a distance, the third - finishing acceleration.
Определялись темп, время и скорость одиночного движения, частота двигательных действий, время сенсомоторных реакций на звуковой и световой раздражители у спортсменок 17-18 лет, занимающихся академической греблей. Разработанная нами методика определения эффекта тренирующего действия моделировала прохождение дистанции в академической гребле: первый период – стартовый разгон, второй – поддержание оптимальной скорости на дистанции, третий – финишное ускорение.
9
Field, Ryan Michael. "High-Speed Wide-Field Time-Correlated Single-Photon Counting Fluorescence Lifetime Imaging Microscopy." Thesis, 2014. https://doi.org/10.7916/D8V40S7T.
Повний текст джерелаАнотація:
Fluorescence microscopy is a powerful imaging technique used in the biological sciences to identify labeled components of a sample with specificity. This is usually accomplished through labeling with fluorescent dyes, isolating these dyes by their spectral signatures with optical filters, and recording the intensity of the fluorescent response. Although these techniques are widely used, fluorescence intensity images can be negatively affected by a variety of factors that impact the fluorescence intensity. Fluorescence lifetime imaging microscopy (FLIM) is an imaging technique that is relatively immune to intensity fluctuations and also provides the unique ability to directly monitor the microenvironment surrounding a fluorophore. Despite the benefits associated with FLIM, the applications to which it is applied are fairly limited due to long image acquisition times and high cost of traditional hardware. Recent advances in complementary metal-oxide-semiconductor (CMOS) single-photon avalanche diodes (SPADs) have enabled the design of low-cost imaging arrays that are capable of recording lifetime images with acquisition times greater than one order of magnitude faster than existing systems. However, these SPAD arrays have yet to realize the full potential of the technology due to limitations in their ability to handle the vast amount of data generated during the commonly used time-correlated single-photon counting (TCSPC) lifetime imaging technique. This thesis presents the design, implementation, characterization, and demonstration of a high speed FLIM imaging system. The components of this design include a CMOS imager chip in a standard 0.13 μm technology containing a custom CMOS SPAD, a 64-by-64 array of these SPADs, pixel control circuitry, independent time-to-digital converters (TDCs), a FLIM specific datapath, and high bandwidth output buffers. In addition to the CMOS imaging array, a complete system was designed and implemented using a printed circuit board (PCB) for capturing data from the imager, creating histograms for the photon arrival data using field-programmable gate arrays, and transferring the data to a computer using a cabled PCIe interface. Finally, software is used to communicate between the imaging system and a computer.The dark count rate of the SPAD was measured to be only 231 Hz at room temperature while maintaining a photon detection probability of up to 30\%. TDCs included on the array have a 62.5 ps resolution and a 64 ns range, which is suitable for measuring the lifetime of most biological fluorophores. Additionally, the on-chip datapath was designed to handle continuous data transfers at rates capable of supporting TCSPC-based lifetime imaging at 100 frames per second. The system level implementation also provides sufficient data throughput for transferring up to 750 frames per second from the imaging system to a computer. The lifetime imaging system was characterized using standard techniques for evaluating SPAD performance and an electrical delay signal for measuring the TDC performance. This thesis concludes with a demonstration of TCSPC-FLIM imaging at 100 frames per second -- the fastest 64-by-64 TCSPC FLIM that has been demonstrated. This system overcomes some of the limitations of existing FLIM systems and has the potential to enable new application domains in dynamic FLIM imaging.
10
Pan, Kuei Yeh, and 潘桂葉. "The Effect of Plyometric Training on Lower Limb Power, Movement Speed, Reaction Time and Agility in Senier High School Squash Players." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/264jeh.
Повний текст джерелаАнотація:
碩士長榮大學
運動競技學系(所)
104
The purpose of this study was to investigate the effects of plyometric training on lower limb power, movement velocity, movement speed, reaction time and agility of senior high school squash players. The subjects of the experiment were twelve male senior high school squash team players. The subjects were randomly divided into the experimental group and the control group by counter-balanced order. The control group received ordinary training while the experimental group received plyometric three a week for either weeks. All the subjects conducted a test before the training. Including, reaction time, agility, the height of vertical jump, length of stand jump, 60-meters sprint and specific movement velocity. Statistical analyses were carried out by utilizing ANCOVA. And the result showed that: After the plyometric either weeks, the experimental group were apparently better than the control group in the height of vertical jump ; and also a noticeable promotion in length of stand jump. As for the 60-meters sprint and specific movement velocity, the experimental group makes a more significantly improvement compared with the control group. Regarding the agility, the experimental group shows significantly higher improvement than the control group. In addition, No significan difference was showed between these two group on reaction time. Finally, the researcher gives out the advice on the basis of the result for coaches and athletes as a reference on training or research.
Книги з теми "Time and speed of a single movement"
1
Lèbre, Jérôme. Vitesses. Paris: Hermann, 2011.
Знайти повний текст джерела
2
Honoré, Carl. In praise of slow: How a worldwide movement is challenging the cult of speed. Toronto: Random House Canada, 2004.
Знайти повний текст джерела
3
In praise of slow: How a worldwide movement is challenging the cult of speed. Toronto: Vintage Canada, 2004.
Знайти повний текст джерела
4
Honoré, Carl, and Carl Honoré. In praise of slowness: How a worldwide movement is challenging the cult of speed. [San Francisco]: HarperSanFrancisco, 2004.
Знайти повний текст джерела
5
In praise of slowness: Challenging the cult of speed. [San Francisco]: HarperSanFrancisco, 2005.
Знайти повний текст джерела
6
Awesome Super Nintendo Secrets 2. Lahaina, USA: Sandwich Islands Publishing, 1993.
Знайти повний текст джерела
7
Temporal precision as a condition for a linear speed-accuracy trade-off in aimed movements. 1986.
Знайти повний текст джерела
8
Differences in movement speed between six year old children and adults on three motor tasks. 1992.
Знайти повний текст джерела
9
Sivakolundu, Ramesh. Implementation of single board computer for real time control of power electronic converter controlled varible speed generation system. 1988.
Знайти повний текст джерела
10
Kubisz, Marzena. Resistance in the Deceleration Lane: Velocentrism, Slow Culture and Everyday Practice. Lang GmbH, Internationaler Verlag der Wissenschaften, Peter, 2014.
Знайти повний текст джерелаЧастини книг з теми "Time and speed of a single movement"
1
Hancock, P. A., and K. M. Newell. "The Movement Speed-Accuracy Relationship in Space-Time." In Motor Behavior, 153–88. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-69749-4_5.
Повний текст джерела
2
Nakanishi, Tomoko M. "Real-Time Element Movement in a Plant." In Novel Plant Imaging and Analysis, 109–68. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-4992-6_4.
Повний текст джерелаАнотація:
AbstractWe developed an imaging method utilizing the available RIs. We developed two types of real-time RI imaging systems (RRIS), one for macroscopic imaging and the other for microscopic imaging. The principle of visualization was the same, converting the radiation to light by a Cs(Tl)I scintillator deposited on a fiber optic plate (FOS). Many nuclides were employed, including 14C, 18F, 22Na, 28Mg, 32P 33P, 35S, 42K, 45Ca, 48V, 54Mn, 55Fe, 59Fe, 65Zn, 86Rb, 109Cd, and 137Cs.Since radiation can penetrate the soil as well as water, the difference between soil culture and water culture was visualized. 137Cs was hardly absorbed by rice roots growing in soil, whereas water culture showed high absorption, which could provide some reassurance after the Fukushima Nuclear Accident and could indicate an important role of soil in firmly adsorbing the radioactive cesium.28Mg and 42K, whose production methods were presented, were applied for RRIS to visualize the absorption image from the roots. In addition to 28Mg and 42K, many nuclides were applied to image absorption in the roots. Each element showed a specific absorption speed and accumulation pattern. The image analysis of the absorption of Mg is presented as an example. Through successive images of the element absorption, phloem flow in the aboveground part of the plant was analyzed. The element absorption was visualized not only in the roots but also in the leaves, a basic study of foliar fertilization.In the case of the microscopic imaging system, a fluorescence microscope was modified to acquire three images at the same time: a light image, fluorescent image, and radiation image. Although the resolution of the image was estimated to be approximately 50 μm, superposition showed the expression site of the transporter gene and the actual 32P-phosphate absorption site to be the same in Arabidopsis roots.
3
Yagi, T., S. Wakasa, N. Tokunaga, Y. Akimoto, and M. Umezu. "Single-cell real-time imaging of flow-induced hemolysis using high-speed microfluidic technology." In IFMBE Proceedings, 2337–40. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-03882-2_621.
Повний текст джерела
4
Pedretti, Giacomo. "One Step in-Memory Solution of Inverse Algebraic Problems." In Special Topics in Information Technology, 63–76. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-62476-7_6.
Повний текст джерелаАнотація:
AbstractMachine learning requires to process large amount of irregular data and extract meaningful information. Von-Neumann architecture is being challenged by such computation, in fact a physical separation between memory and processing unit limits the maximum speed in analyzing lots of data and the majority of time and energy are spent to make information travel from memory to the processor and back. In-memory computing executes operations directly within the memory without any information travelling. In particular, thanks to emerging memory technologies such as memristors, it is possible to program arbitrary real numbers directly in a single memory device in an analog fashion and at the array level, execute algebraic operation in-memory and in one step. In this chapter the latest results in accelerating inverse operation, such as the solution of linear systems, in-memory and in a single computational cycle will be presented.
5
Ezoji, Amer, Romain Pinquie, and Jean François Boujut. "Towards a Better Understanding of Open Source Hardware Design Reuse in Company-Community Collaboration." In Lecture Notes in Mechanical Engineering, 149–54. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-70566-4_24.
Повний текст джерелаАнотація:
AbstractThe open-source-software movement that emerged in the late 90s has recently extended to hardware. In this paper, we try to better understand how the reuse of design solutions facilitates company-community collaboration. On the one hand, based on existing research studies, we analyze three fundamental questions - 1) who wants to reuse a design? 2) Why do they want to reuse a design?, and 3) How do they reuse a design? - from a company perspective and a community perspective. On the other hand, we identified that companies and communities must create a common understanding of the design problems and solution and they could benefit in reusing design artifact to speed up the development time and improve the quality and transferability of the results. However, this research shows that companies and communities don’t use the same type of tools and methods to reuse design knowledge which may cause some problems for collaboration [2].
6
Liu, Yong-Bo, and Xin-Yu Wang. "Gene flow mitigation by ecological approaches." In Gene flow: monitoring, modeling and mitigation, 125–36. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789247480.0009.
Повний текст джерелаАнотація:
Abstract With an increased area of cultivating genetically modified (GM) plants worldwide, the ecological risks of transgenic plants released into the environment have caused concern. One of the risks is the occurrence of gene flow between GM plants and non-GM plants, including their wild relatives. Gene flow data from oilseed rape (Brassica napus), cotton (Gossypium hirsutum), maize (Zea mays), soybean (Glycine max), rice (Oryza sativa), and wheat (Triticum aestivum) indicate that the frequency of pollen-mediated gene flow is negatively related with distance between donor and recipient plants, and the frequency is relatively high in closely related species. We discuss five main ecological approaches to mitigate gene flow from GM plants to non-GM plants, including distance isolation, border or trap crops, barrier crops, agricultural practices, and through biological means. The required isolation distance has been adopted in managing GM crops in some countries, and cultivating tall crops, or border or trap crops, can decrease the requisite isolation distance to mitigate gene flow. Combining several approaches is more effective than a single approach in mitigating gene flow, because the frequency of pollen-mediated gene flow depends on plant genotype, flowering time, wind speed and direction, and other factors. Thus, in the framework of biosafety assessment of GM plants, mitigating the occurrence of gene flow between GM and non-GM plants is a key step to decrease the ecological risk of post- commercial cultivation of GM plants.
7
Sowa, Anna S., Lisa Dussling, Jörg Hagmann, and Sebastian J. Schultheiss. "The power of next-generation sequencing and machine learning for causal gene finding and prediction of phenotypes." In Mutation breeding, genetic diversity and crop adaptation to climate change, 401–10. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789249095.0041.
Повний текст джерелаАнотація:
Abstract The wide application of next-generation sequencing (NGS) has facilitated and accelerated causal gene finding and breeding in the field of plant sciences. A wide variety of techniques and computational strategies is available that needs to be appropriately tailored to the species, genetic architecture of the trait of interest, breeding system and available resources. Utilizing these NGS methods, the typical computational steps of marker discovery, genetic mapping and identification of causal mutations can be achieved in a single step in a cost- and time-efficient manner. Rather than focusing on a few high-impact genetic variants that explain phenotypes, increased computational power allows modelling of phenotypes based on genome-wide molecular markers, known as genomic selection (GS). Solely based on this genotype information, modern GS approaches can accurately predict breeding values for a given trait (the average effects of alleles over all loci that are anticipated to be transferred from the parent to the progeny) based on a large training population of genotyped and phenotyped individuals (Crossa et al., 2017). Once trained, the model offers great reductions in breeding speed and costs. We advocate for improving conventional GS methods by applying advanced techniques based on machine learning (ML) and outline how this approach can also be used for causal gene finding. Subsequent to genetic causes of agronomically important traits, epigenetic mechanisms such as DNA methylation play a crucial role in shaping phenotypes and can become interesting targets in breeding pipelines. We highlight an ML approach shown to detect functional methylation changes sensitively from NGS data. We give an overview about commonly applied strategies and provide practical considerations in choosing and performing NGS-based gene finding and NGS-assisted breeding.
8
Spence, John C. H. "Ole Roemer, Who Started It All." In Lightspeed, 18–26. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198841968.003.0002.
Повний текст джерелаАнотація:
The story of the first measurement of the speed of light by Ole Roemer in 1676. Galileo had discovered the moons of Jupiter with his new telescope, and proposed using observations of their eclipse every forty-two hours as a universal clock for our planet, since they could be seen from practically anywhere. This would keep track of the time at home, and so give a traveller his or her local longitude. (The King of Spain had offered a prize for longitude determination to avoid disasterous shipwrecks.) Roemer noticed that the eclipses were sometimes a little late, which he concluded was due to the time it took light to get from Saturn to Earth and the movement of the Earth between eclipses. His estimate of the time for light to travel from the Sun to Earth was quite accurate. Roemer’s remarkable life story and many other achievements are told.
9
Ángel Mejías Vera, Miguel, and Víctor Manuel Romeo Jiménez. "The Degraded Insular Landscape in the Urban-Rural Interface. Application to the Urban Agglomeration of the South of the Island of Tenerife." In Urban Agglomeration [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102647.
Повний текст джерелаАнотація:
The urban agglomeration of the south of Tenerife is characterized by its accelerated and explosive conformation since the tourist boom of the 80s of the last century. This speed has caused radical landscape changes that have had environmental, economic, social, and spatial repercussions. We try to extract those landscape patterns that characterize this urban model but also to analyze and quantify the landscape degradation of the urban-rural transition zones existing between the tourist and non-tourist nuclei. Through the cartographic and graphic method, typical of spatial thinking and regional geographical analysis, we combine multiple components that characterize and synthesize the substance of the abiotic, biotic, and cultural elements. As a result, we have a diagnosis where the centrality of the tourist nucleus brings together economic activity, the movement of people and vehicles, but at the same time, allows the development of other former rural-based nuclei, transforming them into residential ones, as well as the explosion of buildings dispersed between them. We propose that planning should be based on the landscape patterns that characterize it, starting from the corridor that links the urban centers of the agglomeration.
10
Bhimull, Chandra D. "Speed." In Empire in the Air. NYU Press, 2017. http://dx.doi.org/10.18574/nyu/9781479843473.003.0008.
Повний текст джерелаАнотація:
The third chapter connects rapidity, depth, and altitude to inequality and oppression. It questions how the notion of speed, which is a rate, lost its sense of slowness and became synonymous with fastness. It advocates for an understanding of speed that is culturally and historically informed. Aviation literally turned speed up at a time when access to technological advancements in the maritime world was generating new hopes for Pan Africanism. A temporal and spatial revolution, speed-up established new racial hierarchies. In Britain, government officials and airline executives were drawn to the advantages of direct straight-line travel. They planned to use commercial air power to fashion faster transportation flows between certain parts of the empire. Consequently, some people and places were selected to speed-up, which meant others were made to slow-down. The shift from land- and sea- to air-based movement radically altered the terrains of empire, giving rise to a new dimension and direction of structural inequality.
Тези доповідей конференцій з теми "Time and speed of a single movement"
1
Keshavarzi, Gholamreza, Tracie J. Barber, and Guan Yeoh. "Development of Two-Dimensional Bubble Movement and Development Benchmark Dataset for Numerical Validation." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88717.
Повний текст джерелаАнотація:
The motion and transport of bubbles in fluid flows have many engineering applications. The rise of a bubble has been a point of interest for both numerical and experimental studies. Various tracking methodologies have been developed, including markers, level sets and volume tracking. In order to validate numerical models of bubble flow, detailed experimental data describing the transient bubble shape is needed. This is best found from a 2D comparison rather than 3D experiment because computational resources for determining an accurate shape can be maximized. No real full time shape and subsequent deformation of this 2D bubble has yet been demonstrated. In this paper 2D bubble experiments have been conducted, in which a single bubble has been injected inside a close-walled tank and the rising of the bubble has been captured through a high speed camera. This data is now being used as a benchmark for numerical interface capturing and two phase flow methodology validations.
2
Manukovskiy, Andrey, A. Rubanov, and N. Nedovesov. "INCREASING THE EFFICIENCY OF WATER TRANSPORT OF THE FOREST TO INCREASE THE HYDRODYNAMIC PROPERTIES OF THE RAFT." In Modern machines, equipment and IT solutions for industrial complex: theory and practice. FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov, 2021. http://dx.doi.org/10.34220/mmeitsic2021_80-85.
Повний текст джерелаАнотація:
Of all the known modern types of water transport of the forest, the most promising is timber rafting, which, when used, has both positive and negative properties. Negative indicators include such indicators as: seasonality of work, since use in the winter period is impossible, loss of wood when unloading logs onto water and a raft, large dimensions, complexity of management, the need to unload a raft when unloading it. Passes through non-standard sections of the river bed and subsequent formations, special requirements for the dimensions of the waterway, speed limits and others.
One of the most acute problems caused by huge hydrodynamic resistance to movement, which increases with an increase in towing speed, is the limitation of the speed of movement of the raft in the water area. In this regard, the maximum speed of the raft in calm weather reaches no more than 1 1.2 m
/ s, while two or more powerful tugs are involved.
The limited time frame for rafting on wooden rafts is due to the flood period during the spring floods and floods, and they have fallen on hard times. Increasing the raft’s allowable towing speed will shorten the raft’s transport time. A decrease in hydrodynamic resistance when the raft is moving will increase the maximum allowable speed of its towing, which will have a positive effect on the efficiency of timber rafting.
Based on the analysis of existing known designs of modern rafts, as well as methods of influencing the reduction of hydrodynamic resistance in the field of shipbuilding, a number of methods have been proposed for reducing the hydrodynamic resistance to the movement of the raft. Methods of reducing the resistance to the movement of the raft by changing the features of its formation by placing separate sections or beams in the streamlined material, the introduction of hydrodynamic fairings are considered. The proposed methods for reducing the hydrodynamic resistance can significantly increase the efficiency of timber rafting.
3
Marzban, Mostapha, and Aria Alasty. "Stability Control of an Amphibious Single Wheel Robot." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-44020.
Повний текст джерелаАнотація:
Single wheel robots are typically those kinds of robots which contain all the necessary mechanizations, namely the stabilization and driving mechanizations, within a shell-liked housing appearing analogous to a wheel. These robots have proved to be useful in various fields of industry due to their advantages of giving high instant acceleration and maintaining high cruise speeds for considerable amount of time in addition to being compact and small. It is a sharp-edged wheel actuated by a spinning flywheel for steering and a drive motor for propulsion. The spinning flywheel acts as a gyroscope to stabilize the robot and it can be tilted to achieve steering. In this paper first the kinematics of a single wheel robot, like Gyrover, in water is considered and then a simple mechanism for its movement in water is proposed. After hydrodynamic analysis of the robot a complete dynamics model is designed with Lagrange energy method. Then a stabilizer controller is designed to balance the robot with nonlinear control approach. For simplicity the added mass effect in hydrodynamic analysis, has been neglected. This complete model can be used for examining the behavior of the robot in designing a controller.
4
Zhou, Wei, Xue xun Guo, Xiaofei Pei, Chengcai Zhang, Jun Yan, Jialei Xia, and Yu Tang. "Modelling and Real Vehicle Verification of Drivability Evaluation based on Longitudinal and Lateral Movement Characteristics." In FISITA World Congress 2021. FISITA, 2021. http://dx.doi.org/10.46720/f2021-vdc-104.
Повний текст джерелаАнотація:
"In order to overcome the shortcomings of subjective evaluation that experienced testers and much time are required, and the evaluation results are closely related to human subjective awareness and environmental factors. An objective evaluation model of vehicle drivability based on longitudinal and lateral movement characteristics is proposed. It reveals the quality of vehicle drivability by analyzing the objective parameters, which are obtained through on-board sensors. First , a vehicle drivability evaluation model framework is given, including signal collection, data cleaning, feature extraction and automated scoring. Then, according to the longitudinal and lateral dynamic model, objective parameters such as steering wheel angle, vehicle speed, longitudinal acceleration, lateral acceleration, engine speed, engine torque, gear shift signal, accelerator pedal opening and braking signal are obtained from the developed Intelligent drivability objective evaluation tool (I-DOET) hardware platform，It is composed of CAN module and AD analog quantity module, which can be used to obtain objective parameters in vehicle-mounted OBD and inertial navigation sensors，such as IMU or acceleration sensors. Thereafter, Fuzzy analytic hierarchy process（FAHP）is used to construct an objective drivability evaluation model. The subjective weight is determined by a team of calibration engineering with rich evaluation experience and full-time professors from Wuhan University of Technology. The fuzzy logic matrix is obtained by analyzing a large number of vehicle tests in the early stage. Finally, a real-vehicle verification is carried out with a single-line shifting conditions. The experimental results show that the vehicle drivability evaluation model based on longitudinal and lateral movement characteristics can scientifically and effectively evaluate the vehicle drivability. The objective drivability evaluation model can not only be used for the evaluation of drivability, but also provide a theoretical basis for the objective evaluation of vehicle ride comfort and handing stability. In addition, the model is also suitable for driving evaluation of new energy vehicles and autonomous vehicles."
5
Johnson, Kristyn B., Donald H. Ferguson, Robert S. Tempke, and Andrew C. Nix. "Application of a Convolutional Neural Network for Wave Mode Identification in a Rotating Detonation Combustor Using High-Speed Imaging." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-15676.
Повний текст джерелаАнотація:
Abstract Utilizing a neural network, individual down-axis images of combustion waves in a Rotating Detonation Engine (RDE) can be classified according to the number of detonation waves present and their directional behavior. While the ability to identify the number of waves present within individual images might be intuitive, the further classification of wave rotational direction is a result of the detonation wave’s profile, which suggests its angular direction of movement. The application of deep learning is highly adaptive and therefore can be trained for a variety of image collection methods across RDE study platforms. In this study, a supervised approach is employed where a series of manually classified images is provided to a neural network for the purpose of optimizing the classification performance of the network. These images, referred to as the training set, are individually labeled as one of ten modes present in an experimental RDE. Possible classifications include deflagration, clockwise and counterclockwise variants of co-rotational detonation waves with quantities ranging from one to three waves, as well as single, double and triple counter-rotating detonation waves. After training the network, a second set of manually classified images, referred to as the validation set, is used to evaluate the performance of the model. The ability to predict the detonation wave mode in a single image using a trained neural network substantially reduces computational complexity by circumnavigating the need to evaluate the temporal behavior of individual pixels throughout time. Results suggest that while image quality is critical, it is possible to accurately identify the modal behavior of the detonation wave based on only a single image rather than a sequence of images or signal processing. Successful identification of wave behavior using image classification serves as a stepping stone for further machine learning integration in RDE research and comprehensive real-time diagnostics.
6
Infantino, Daniele, Francesca Satta, Daniele Simoni, Marina Ubaldi, Pietro Zunino, and Francesco Bertini. "Analysis of a LPT Rotor Blade for a Geared Engine: Part II — Characterization of the Time-Varying Flow Field in a Single Stage Research Turbine." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57725.
Повний текст джерелаАнотація:
The present paper is the second part of a two-part paper focused on the design and the analysis of an optimized rotor blade for a geared open rotor engine. This part is focused on the experimental investigation of the three-dimensional unsteady flow field at the exit plane of a rotor row installed in a large scale single-stage low speed research turbine. The investigation is aimed at in depth characterizing the wake-boundary layer and the vortex-vortex interaction processes induced by the rotor-stator relative motion. Measurements have been carried out at a typical aeroengine cruise condition Reynolds number. The rotor blade aerodynamic loadings at different blade spans have been measured. A five-hole probe has been used to assess the row efficiency and detailed hot-wire phase-locked ensemble-averaged data have been analyzed to characterize the three-dimensional time-dependent flow field at the rotor exit plane. Results clearly highlight a significant distortion of the rotor blade wake and tip vortex during the migration of the high turbulence regions (wake and secondary flows) associated with the upstream stator. The unsteady interaction between the stator secondary flows and the rotor passage vortex provokes a time dependent movement of the low momentum area at the hub surface, sensibly modifying the penetration of the rotor secondary flows in an incoming stator wake passage period. The comparison of deterministic and random velocity fluctuations also allows the distinction between the structures generated by the stator and those due to the rotor.
7
Busch, Eirene Rebecca, Manuel Keßler, and Ewald Krämer. "Numerical Investigation of Counter-Rotating Open Rotor Noise Emission in Different Flight Conditions." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68625.
Повний текст джерелаАнотація:
Noise emission of a 9×7 and 8×8 open rotor configuration in cruise and in take-off conditions is examined by 3D unsteady numerical simulations utilising the chimera method to represent rotor movement. The acoustic analysis has been carried out with a Ffowcs Williams-Hawkings code over one rotor revolution with a resolution of 360 time steps. To ensure covering of all sources while keeping numerical losses low different hull surfaces have been examined. The comparison of two configurations at different flight conditions shows two main noise generating effects: the single rotor emission and emission caused by interaction of the rotors. The single rotor emission can mostly be seen in the rotor plane whereas the interaction can be examined at an angle of 20 to 45 and 135 to 155 degrees to the rotating axis with approximately the same share of total noise in take-off conditions. In cruise conditions the single rotor emission prevails over the interaction. This can be explained by the transonic blade tip speeds during cruise. Due to the reduced tip speeds in take-off interaction noise contributes to the total noise with a higher share than in cruise conditions. The 8×8-configuration shows higher noise emissions by interaction since the rotor-rotor interactions occur simultaneously.
8
Navarro-Devia, John Henry, Dzung Viet Dao, Yun Chen, and Huaizhong Li. "Analysis of Vibration Signals in Monitoring Titanium End Milling Process Using Triaxial Accelerometer." In ASME 2021 16th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/msec2021-64688.
Повний текст джерелаАнотація:
Abstract Vibrations during milling of hard-to-cut materials can cause low productivity, inferior quality and short tool life. It is one of the common issues in the machining of hard-to-cut materials employed in aerospace applications, such as titanium alloys. This paper presents an analysis of the vibration signals in the 3 axes of movement during titanium end milling, under diverse cutting parameters, manipulating spindle speed and feed rate. Signals were obtained using a triaxial accelerometer and processed in MATLAB. The analysis was conducted in the frequency-domain and the time-frequency domain. The results show that high-frequency vibration could occur in any direction with different amplitudes. Response on each axis depends on spindle speed, feed, and type of milling. A frequency component continually appeared in each axis regardless of cutting conditions and is located near the natural frequencies. Finally, the triaxial accelerations were compared for the milling cases with a new and a worn tool. Results highlight the importance and need for continuous monitoring of vibration in the 3 axes, instead of only using a single-channel signal, providing experimental data which could expand knowledge relating to the milling of titanium alloys.
9
Chen, J., H. Hasemann, U. Seidel, D. Jin, X. Huang, and M. Rautenberg. "The Interpretation of Internal Pressure Patterns of Rotating Stall in Centrifugal Compressor Impellers." In ASME 1993 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1993. http://dx.doi.org/10.1115/93-gt-192.
Повний текст джерелаАнотація:
Dynamic pressure measurement on the shroud wall for a high performance single stage centrifugal compressor has been implemented to record the unsteady pressure data during rotating stall. Apart from the frequency analysis of the stall characteristics, a computer-aided method has been developed to enable the unsteady internal pressure patterns inside the blade channel near shroud surface to be described and shown in an animated visualisation. Typical results of internal pressure patterns for a backswept impeller with two cell rotating stall occurrence at the impeller speed of 16000 rpm are presented in detail. The internal flow structure can be interpreted by pressure patterns of three types emerged consecutively within one time period of stall pressure oscillation: the normal pattern, the mixed pattern and the stalled pattern. The mixed pattern is characterized by a coexistence of the reverse movement of high pressure region towards inlet and the inlet separation. The stalled pattern is characterized by a collapse of pressure loadings in the blade channel. Such observation is thought to be useful for exploring the flow mechanism of rotating stall.
10
Renner, Alex, Joseph Holub, Shubang Sridhar, Gabe Evans, and Eliot Winer. "A Virtual Reality Application for Additive Manufacturing Process Training." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-47807.
Повний текст джерелаАнотація:
The promise of cheap and widely available 3D printers may be one of the best and worst aspects of Additive Manufacturing (AM). A non-technical consumer may pay significantly more for a 3D printer with “no assembly required”. Since it is reasonable to assume that they may not understand how the printer works and what will come out of it, they may wind up returning it because it does not meet their expectations. While consumers are starting to use 3D printers, designers in industry are utilizing Rapid Prototyping (RP) machines to manufacture final products in addition to prototypes. Designers will need to know AM principles in order to communicate design specifications to a RP lab technician so that a part passes Quality Assurance inspection. Training users on fundamental layer-based manufacturing methods can assist before and after a 3D printer purchase and reduce the strain on RP labs in industry. This paper presents an extensible software application that simulates an AM process in a Virtual Reality (VR) environment. The application parses machine component movements and printed segment attributes from G-code files exported from the MakerBot® Computer Aided Manufacturing (CAM) software. Position, speed, and type of movement are used to simulate the physical machine movements. A print “segment” is created at the start and end positions of a print movement. Color-coding segment attributes and modifying their size and shape establishes a visual relationship between terminology for a print setting and its representation in the virtual environment. This visual relationship between printed segments and print settings makes it easier to learn the 3D printing process and associated terminology. Novice and expert users can modify print settings in the virtual environment before and after printing a prototype. Identifying and fixing a mistake in the virtual environment reduces the time and cost to print a part with the desired quality. Training multidisciplinary users in a virtual world allows them to explore AM processes in detail from any angle or scale desired. This application has been tested in a cube shaped virtual reality CAVE system with each side measuring ten feet powered by a 96-node graphics computer cluster. Approximately 20 hours of demonstrations have been performed for public outreach programs related to STEM initiatives and visitors from industry who have had a variety of AM experience.
Звіти організацій з теми "Time and speed of a single movement"
1
Zilberman, Mark. Methods to Test the “Dimming Effect” Produced by a Decrease in the Number of Photons Received from Receding Light Sources. Intellectual Archive, November 2020. http://dx.doi.org/10.32370/iaj.2437.
Повний текст джерелаАнотація:
The hypothetical “Dimming Effect” describes the change of the number of photons arriving from a moving light source per unit of time. In non-relativistic systems, the “Dimming effect” may occur due to the growing distance of light sources moving away from the receiver. This means that due to the growing distance, the photons continuously require more time to reach the receiver, which reduces the number of received photons per time unit compared to the number of emitted photons. Understandably, the proposed “Dimming effect” must be tested (confirmed or rejected) through observations. a. This article provides the formula for the calculation of “Dimming effect” values using the redshift parameter Z widely used in astronomy. b. The “Dimming effect” can possibly be detected utilizing the orbital movement of the Earth around the Sun. In accordance to the “Dimming effect”, observers on Earth will view 1.0001 more photons per time unit emitted by stars located near the ecliptic plane in the direction of the Earth orbiting the Sun. And, in contrast, observers will view only 0.9999 photons per time unit emitted by stars located near the ecliptic plane in the direction opposite to the Earth orbiting the Sun. Calculating precise measurements of the same stars within a 6-month period can possibly detect this difference. These changes in brightness are not only for specific stars, as the change in brightness takes place for all stars near the ecliptic in the direction of the Earth’s orbit around the Sun and in the opposite direction. c. The “Dimming effect” can possibly be detected in a physics laboratory using a moving light source (or mirror) and photon counters located in the direction of travel and in the opposite direction. d. In theory, Dilation of time can also be used for testing the existence of the “Dimming effect.” However, in experiments on Earth this effect appears in only the 14th digit after the decimal point and testing does not appear to be feasible. e. Why is it important to test the “Dimming effect?” If confirmed, it would allow astronomers to adjust values of "Standard Candles" used in astronomy. Since “Standard Candles” are critical in various cosmological models, the “Dimming effect” can correct models and/or reveal and support new models. If it is proved that the “Dimming effect” does not exist, it will mean that the number of photons arriving per unit of time does not depend on the speed of the light source and observer, which is not so apparent.
2
Duvvuri, Sarvani, and Srinivas S. Pulugurtha. Researching Relationships between Truck Travel Time Performance Measures and On-Network and Off-Network Characteristics. Mineta Transportation Institute, July 2021. http://dx.doi.org/10.31979/mti.2021.1946.
Повний текст джерелаАнотація:
Trucks serve significant amount of freight tonnage and are more susceptible to complex interactions with other vehicles in a traffic stream. While traffic congestion continues to be a significant ‘highway’ problem, delays in truck travel result in loss of revenue to the trucking companies. There is a significant research on the traffic congestion mitigation, but a very few studies focused on data exclusive to trucks. This research is aimed at a regional-level analysis of truck travel time data to identify roads for improving mobility and reducing congestion for truck traffic. The objectives of the research are to compute and evaluate the truck travel time performance measures (by time of the day and day of the week) and use selected truck travel time performance measures to examine their correlation with on-network and off-network characteristics. Truck travel time data for the year 2019 were obtained and processed at the link level for Mecklenburg County, Wake County, and Buncombe County, NC. Various truck travel time performance measures were computed by time of the day and day of the week. Pearson correlation coefficient analysis was performed to select the average travel time (ATT), planning time index (PTI), travel time index (TTI), and buffer time index (BTI) for further analysis. On-network characteristics such as the speed limit, reference speed, annual average daily traffic (AADT), and the number of through lanes were extracted for each link. Similarly, off-network characteristics such as land use and demographic data in the near vicinity of each selected link were captured using 0.25 miles and 0.50 miles as buffer widths. The relationships between the selected truck travel time performance measures and on-network and off-network characteristics were then analyzed using Pearson correlation coefficient analysis. The results indicate that urban areas, high-volume roads, and principal arterial roads are positively correlated with the truck travel time performance measures. Further, the presence of agricultural, light commercial, heavy commercial, light industrial, single-family residential, multi-family residential, office, transportation, and medical land uses increase the truck travel time performance measures (decrease the operational performance). The methodological approach and findings can be used in identifying potential areas to serve as truck priority zones and for planning decentralized delivery locations.
3
Zilberman, Mark. Methods to Test the “Dimming Effect” Produced by a Decrease in the Number of Photons Received from Receding Light Sources. Intellectual Archive, June 2021. http://dx.doi.org/10.32370/ia_2021_06_22.
Повний текст джерелаАнотація:
The hypothetical “Dimming effect” describes the change of the number of photons arriving from a receding light source per unit of time. In non-relativistic systems,the "Dimming effect" occurs due to the fact that as light sources move away, the distance between the emitter and the receiver constantly increases, and the photons always take longer to reach the receiver. This reduces the number of photons received per time unit compared to the number of emitted photons per time unit. Negligible for speeds incomparable with the speed of light c, the "Dimming effect" can be very significant for speeds above 0.1c. “Dimming effect” can possibly be tested in a physics labor-atory using a moving light source (or mirror) and photon counters located in the travel direction and in opposite direction. It can possibly also be tested utilizing the orbital movement of the Earth around the Sun. If confirmed, “Dimming effect” would allow astronomers to adjust values of the "Standard Candles", which are critical in cosmological models. Absence of “Dimming effect” will mean that the number of photons arriving per time unit does not depend on the relative speed of light source and observer,which is not so apparent
4
Chen, Pictiaw, Boaz Zion, and Michael J. McCarthy. Utilization of NMR Technology for Internal Nondestructive Quality Evaluation of Fruits and Vegetables. United States Department of Agriculture, September 1994. http://dx.doi.org/10.32747/1994.7568778.bard.
Повний текст джерелаАнотація:
Objective: The objective of this research was to investigate the potential use of NMR for evaluating various internal quality factors of fruits and vegetables, leading to the eventual development of practical techniques that are useful for future development of NMR sensors. Summary: Investigation on NMR imaging, one-dimension NMR projection, and single-pulse free-induction-decay (FID) spectrum led to the development of high-speed NMR techniques for real-time sensing of internal quality of selected fruits. NMR imaging can be used for detecting internal defects and various quality factors such as bruises, dry regions, worm damage, stage of ripeness, tissue breakdown, and the presence of voids, seeds, sprouts, and pits. The one-dimension (1-D) image profile technique, in which the 1-D projection of the NMR signal of a selected slice of the intact fruit is recorded, is suitable for detecting tissue breakdown regions, presence of pits, and other defects in fruits. The oil and sugar content of fruits can be determined from the single-pulse FID spectrum measurement, in which a surface coil is used to acquire the FID spectrum and the ratio of the resonance peaks is used as the quality index. The latter two techniques are suitable for high-speed sorting of fruits. The most important accomplishment is the successful development of high-speed NMR techniques for determining internal quality of fruits while they are moving at speed up to 30 cm/s. This accomplishment is an important step toward the development of NMR techniques for on-line sorting of fruits and vegetables.