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Author(s):  
Xiaoping Ren ◽  
Fang Deng

We address the propagation dynamics of two-dimensional multi-peak solitons in the optical lattices based on the fractional Schrödinger equation. The effect of Lévy index and lattice depth on the band-gap structure of optical lattices are presented. Two-, three-, four-, six- and eight-peak solitons all can exist in the first gap and be stable in a wide region of their existence domain. The effective width, maximal peak value and the power of soliton are also studied. It indicates that the Lévy index plays a significant role on the properties of solitons.


2021 ◽  
Vol 3 ◽  
Author(s):  
Hirotaka Sugino ◽  
Junichi Ushiyama

Previous psychological studies using questionnaires have consistently reported that athletes have superior motor imagery ability, both for sports-specific and for sports-non-specific movements. However, regarding motor imagery of sports-non-specific movements, no physiological studies have demonstrated differences in neural activity between athletes and non-athletes. The purpose of this study was to examine the differences in sensorimotor rhythms during kinesthetic motor imagery (KMI) of sports-non-specific movements between gymnasts and non-gymnasts. We selected gymnasts as an example population because they are likely to have particularly superior motor imagery ability due to frequent usage of motor imagery, including KMI as part of daily practice. Healthy young participants (16 gymnasts and 16 non-gymnasts) performed repeated motor execution and KMI of sports-non-specific movements (wrist dorsiflexion and shoulder abduction of the dominant hand). Scalp electroencephalogram (EEG) was recorded over the contralateral sensorimotor cortex. During motor execution and KMI, sensorimotor EEG power is known to decrease in the α- (8–15 Hz) and β-bands (16–35 Hz), referred to as event-related desynchronization (ERD). We calculated the maximal peak of ERD both in the α- (αERDmax) and β-bands (βERDmax) as a measure of changes in corticospinal excitability. αERDmax was significantly greater in gymnasts, who subjectively evaluated their KMI as being more vivid in the psychological questionnaire. On the other hand, βERDmax was greater in gymnasts only for shoulder abduction KMI. These findings suggest gymnasts' signature of flexibly modulating sensorimotor rhythms with no movements, which may be the basis of their superior ability of KMI for sports-non-specific movements.


Author(s):  
Mohamed Almghraby ◽  
◽  
Abdelrady Okasha Elnady* ◽  

Face mask detection has made considerable progress in the field of computer vision since the start of the Covid-19 epidemic. Many efforts are being made to develop software that can detect whether or not someone is wearing a mask. Many methods and strategies have been used to construct face detection models. A created model for detecting face masks is described in this paper, which uses “deep learning”, “TensorFlow”, “Keras”, and “OpenCV”. The MobilenetV2 architecture is used as a foundation for the classifier to perform real-time mask identification. The present model dedicates 80 percent of the training dataset to training and 20% to testing, and splits the training dataset into 80% training and 20% validation, resulting in a final model with 65 percent of the dataset for training, 15 percent for validation, and 20% for testing. The optimization approach used in this experiment is “stochastic gradient descent” with momentum (“SGD”), with a learning rate of 0.001 and momentum of 0.85. The training and validation accuracy rose until they reached their maximal peak at epoch 12, with 99% training accuracy and 98% validation accuracy. The model's training and validation losses both reduced until they reached their lowest at epoch 12, with a validation loss of 0.050% and a training loss of less than 0.025%. This system allows for real-time detection of someone is missing the appropriate face mask. This model is particularly resource-efficient when it comes to deployment, thus it can be employed for safety. So, this technique can be merged with embedded application systems at public places and public services places as airports, trains stations, workplaces, and schools to ensure subordination to the guidelines for public safety. The current version is compatible with both IP and non-IP cameras. Web and desktop apps can use the live video feed for detection. The program can also be linked to the entrance gates, allowing only those who are wearing masks to enter. It can also be used in shopping malls and universities.


Author(s):  
Guanhao Li ◽  
Clemens Puppe ◽  
Arkadii Slinko
Keyword(s):  

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.


2020 ◽  
Vol 29 (8) ◽  
pp. 1218-1221
Author(s):  
Matheus Lima Oliveira ◽  
Isabela Christina Ferreira ◽  
Kariny Realino Ferreira ◽  
Gabriela Silveira-Nunes ◽  
Michelle Almeida Barbosa ◽  
...  

Context: Strength assessment is essential to prescribe exercise in sports and rehabilitation. Low-cost valid equipment may allow continuous monitoring of training. Objective: To examine the validity of a very low-cost hanging scale by comparing differences in the measures of peak force to a laboratory grade load cell during shoulder abduction, flexion, extension, and internal and external rotations. Design: Analytical study. Participants: Thirty-two healthy subjects (18 women, age 26 [10] y, height 172 [8] cm, mass 69 [13] kg, body mass index 23 [4] kg/m2). Main Outcome Measures: The dependent variable was the maximal peak force (in kilogram-force). The independent variable was the instrument (laboratory grade load cell and hanging scale). Results: No differences were observed while comparing the results. The intraclass correlation coefficients1,1 ranged from .96 to .99, showing excellent results. The Cronbach alpha test also returned >.99 for all comparisons. The SEM ranged from 0.02 to 0.04 kgf, with an averaged SD from 0.24 to 0.38 kgf. The correlation was classified as high for all tested movements (r > .99; P < .001), with excellent adjusted coefficients of determination (.96 < r2 < .99). Bland–Altman results showed high levels of agreement with bias ranging from 0.27 to 0.48. Conclusions: Hanging scale provides valid measures of isometric strength with similar output measures as laboratory grade load cell.


2020 ◽  
pp. 61-65

The aim of the work is dedicated isolation of anthocyanins by ethanol from herbal plant of Occimum basilicum L. Lamiaceae basis. The were studied influencing of temperature, concentration of ethanol to isolation of anthocyanins. There were passed investigations on studying influence level of heating and hydromodule system of rav material-solvent to maximal isolating of anthocyanins. The colors define by fotokolorometrical method at wave length 400-600 nm. There are shown at 540 nm maximal peak of anthocyanins and it is geven as a grapfical diagram. From the obtained depends on content of alcohol in aquatic solution from outlet of colors is defined optimal content of spirt. There are determined chemical content of color, extracted from basis leaf, there are studied organoleptical and physico-chemical parameters of the obtained natural colors. Quantity of carbohydrates and vitamins are determined on total methodics.


SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A217-A217
Author(s):  
W Li ◽  
S Gakwaya ◽  
J Masse ◽  
F Series

Abstract Introduction Soft palate muscles are crucial in the maintenance of UA patency. This study aimed to investigate the fatigability of soft palate muscles and to quantify its effects on velopharyngeal UA dynamic properties in OSA patients and control subjects. Methods 8 control (AHI ≤ 10 /h), 21 OSA patients (13 with mild/moderate disease: 10 /h &lt; AHI ≤ 20 /h and 8 with moderate/severe: AHI &gt; 20/h) were included in the study. Subjects were asked to develop repetitive intra-oral positive pressure during cheek-bulging maneuvers while wearing a mouth piece to keep the jaw opened. Subjects were asked to develop sustained maximal bulging pressure for 5 sec every 10 sec until the peak pressure could not reach 85% of baseline maximal pressure for 2 consecutive times. UA dynamic properties were assessed by measuring instantaneous airflow and velopharyngeal pressure in response to phrenic nerve magnetic stimulation (PNMS) performed before, immediately and every 3 minutes after the fatiguing protocol for a maximum of 30 minutes’ recovery time. UA closing pressure (Pcrit) was estimated by modeling the flow/pressure relationship in response to PNMS. Results The sex, age, BMI and the soft palate mechanical properties (including the baseline strength, endurance time, total muscle work) did not significantly differ between the 3 groups. Maximal peak bulging pressure measured using cheek-bulging maneuver significantly changed following the fatigue task (p &lt; 0.05). Baseline velopharyngeal Pcrit were less negative in moderate/severe OSA group compared to mild/moderate OSA (-6.5±2.6 vs. -11.9±3.2, p &lt; 0.05). In mild/moderate OSA patients, PNMS-induced drop in maximal instantaneous airflow tend to increase 3 mins after the fatiguing trial compared to baseline (22.7±21.1 l.s-1vs. 9.6±5.8 l.s-1, p &lt; 0.1), and their Velopharyngeal linear resistance 3 mins after the fatiguing trial tend to be higher than the moderate/severe OSA group (3.9 ± 5.0 cmH2O·l−1·s−1 vs. 1.8 ± 1.1 cmH2O·l−1·s−1, p&lt; 0.1). Conclusion The cheek-bulging maneuver could induce soft palate muscle fatigue, with no difference observed in soft palate mechanical performances among patients with different OSA severity. The fatiguing maneuver could further alter velopharyngeal UA mechanical properties in patients with mild/moderate OSA. Support SBD from IUCPQ Foundation


2020 ◽  
pp. 100-103
Author(s):  
Ermek Kenzhebulatovich Khusainov ◽  
◽  
Yuriy Vladimirovich Kondratyev ◽  

The paper considers efficiency of distance protection with adaptation to rectifier converters of traction substations with different number of pulsations. The authors have revealed the influence of inclination of the external characteristic of rectifier converters on total efficiency of protection. They have also introduced notions for indicators of efficiency of distance protection with adaptation: сoefficient that determines the increase ratio of peak operating current; coefficient that determines the decrease ratio of minimal voltage on traction substation buses; coefficient that determines the increase ratio of maximal peak power of catenary feeder realized by 3.3 kV direct current. The paper presents methods of their calculation.


Author(s):  
Zongxin Zhang ◽  
Fenxiang Wu ◽  
Jiabing Hu ◽  
Xiaojun Yang ◽  
Jiayan Gui ◽  
...  

In this paper, we report the recent progress on the $1~\text{PW}/0.1~\text{Hz}$ laser beamline of Shanghai Superintense Ultrafast Laser Facility (SULF). The SULF-1 PW laser beamline is based on the double chirped pulse amplification (CPA) scheme, which can generate laser pulses of 50.8 J at 0.1 Hz after the final amplifier; the shot-to-shot energy fluctuation of the amplified pulse is as low as 1.2% (std). After compression, the pulse duration of 29.6 fs is achieved, which can support a maximal peak power of 1 PW. The contrast ratio at $-80~\text{ps}$ before main pulse is measured to be $2.5\times 10^{-11}$ . The focused peak intensity is improved by optimizing the angular dispersion in the grating compressor. The maximal focused peak intensity can reach $2.7\times 10^{19}~\text{W}/\text{cm}^{2}$ even with an $f/26.5$ off-axis parabolic mirror. The horizontal and vertical angular pointing fluctuations in 1 h are measured to be 1.89 and $2.45~\unicode[STIX]{x03BC}\text{rad}$ , respectively. The moderate repetition rate and the good stability are desirable characteristics for laser–matter interactions. The SULF-1 PW laser beamline is now in the phase of commissioning, and preliminary experiments of particle acceleration and secondary radiation under 300–400 TW/0.1 Hz laser condition have been implemented. The progress on the experiments and the daily stable operation of the laser demonstrate the availability of the SULF-1 PW beamline.


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