scholarly journals INVESTIGATION OF THE EFFECT OF WALKING SPEED ON LEG MUSCLE REACTION BY COMPLEXITY-BASED ANALYSIS OF ELECTROMYOGRAM (EMG) SIGNALS

Fractals ◽  
2021 ◽  
pp. 2150254
Author(s):  
HAMIDREZA NAMAZI ◽  
NAJMEH PAKNIYAT
Keyword(s):  
Walking Speed ◽  
Fractal Theory ◽  
Research Area ◽  
Sample Entropy ◽  
Physiological Signals ◽  
Analysis Method ◽  
Clear Trend ◽  
Important Research Area ◽  
Leg Muscle ◽  
Walking Speeds

An important research area in physiological and sport sciences is the analysis of the variations of the muscle reaction due to changes in walking speed. In this paper, we investigated the effect of walking speed variations on leg muscle reaction by the analysis of Electromyogram (EMG) signals at different walking inclines. For this purpose, we benefited from fractal theory and sample entropy to analyze how the complexity of EMG signals changes at different walking speeds. According to the results, although fractal theory could not show a clear trend between the variations of the complexity of EMG signals and the variations of the walking speed, however, based on the results, increasing the speed of walking in the case of different inclines is mapped on to the decrement of the sample entropy of EMG signals. Therefore, sample entropy could decode the effect of walking speed on the reaction of leg muscle. This analysis method could be applied to analyze the variations of other physiological signals of humans durin walking.

scholarly journals Complexity-Based Decoding of the Coupling Among Heart Rate Variability (HRV) and Walking Path

2020 ◽  
Vol 11 ◽  
Author(s):  
Shahul Mujib Kamal ◽  
Mohammad Hossein Babini ◽  
Ondrej Krejcar ◽  
Hamidreza Namazi
Keyword(s):  
Heart Rate ◽  
Time Series ◽  
Heart Rate Variability ◽  
Fractal Dimension ◽  
Daily Life ◽  
Fractal Theory ◽  
Sample Entropy ◽  
Physiological Signals ◽  
Everyday Activity ◽  
First Time

Walking is an everyday activity in our daily life. Because walking affects heart rate variability, in this research, for the first time, we analyzed the coupling among the alterations of the complexity of walking paths and heart rate. We benefited from the fractal theory and sample entropy to evaluate the influence of the complexity of paths on the complexity of heart rate variability (HRV) during walking. We calculated the fractal exponent and sample entropy of the R-R time series for nine participants who walked on four paths with various complexities. The findings showed a strong coupling among the alterations of fractal dimension (an indicator of complexity) of HRV and the walking paths. Besides, the result of the analysis of sample entropy also verified the obtained results from the fractal analysis. In further studies, we can analyze the coupling among the alterations of the complexities of other physiological signals and walking paths.

Nonlinear Regression Analysis of Herbicide Absorption Studies

Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 601-610 ◽  
Author(s):  
Andrew R. Kniss ◽  
Joseph D. Vassios ◽  
Scott J. Nissen ◽  
Christian Ritz
Keyword(s):  
Nonlinear Models ◽  
Research Area ◽  
Analysis Method ◽  
Absorption Data ◽  
The Past ◽  
Absorption Studies ◽  
Important Research Area ◽  
Standardized Method ◽  
Treatment Structure ◽  
Over Time

Although foliar herbicide absorption has been studied intensively, there is currently no standardized method for data analysis when evaluating herbicide absorption over time. Most peer-reviewed journals require the treatment structure of data be incorporated in the analysis; however, many herbicide absorption studies published in the past 5 yr do not account for the time structure of the experiment. Herbicide absorption studies have been presented in a variety of ways, making it difficult to compare results among studies. The objective of this article is to propose possible nonlinear models to analyze herbicide absorption data and to provide a stepwise framework so that researchers may standardize the analysis method in this important research area. Asymptotic regression and rectangular hyperbolic models with similar parameterizations are proposed, so that the maximum herbicide absorption and absorption rate may be adequately modeled and statistically compared among treatments. Adoption of these models for herbicide absorption analysis over time will provide a standardized method making comparison of results within and among studies more practical.

scholarly journals ANALYSIS OF THE CORRELATION BETWEEN BRAIN AND SKIN REACTIONS TO DIFFERENT TYPES OF MUSIC

Fractals ◽  
2021 ◽  
Vol 29 (02) ◽  
pp. 2150124
Author(s):  
HAMIDREZA NAMAZI ◽  
DUMITRU BALEANU ◽  
SHAFIUL OMAM ◽  
ONDREJ KREJCAR
Keyword(s):  
Rock Music ◽  
Research Area ◽  
Sample Entropy ◽  
Skin Reactions ◽  
Dimension Formula ◽  
Different Types ◽  
Skin Response ◽  
Important Research Area ◽  
Electroencephalogram Eeg ◽  
The Brain

Evaluation of the correlation among the activities of various organs is an important research area in physiology. In this paper, we analyzed the correlation between the brain and skin reactions in response to various auditory stimuli. We played three different music (relaxing, pop, and rock music) to eleven subjects (4 M and 7 F, 18–22 years old) and accordingly analyzed the changes in the complexity of Electroencephalogram (EEG) and Galvanic Skin Response (GSR) signals by calculating their fractal exponent and sample entropy. A strong correlation was observed among the alterations of the complexity of GSR and EEG signals in the case of fractal dimension ([Formula: see text]) and also sample entropy ([Formula: see text]), which indicates the correlation between the activities of skin and brain. This analysis method could be further applied to investigate the correlation among the activities of the brain and other organs of the human body.

scholarly journals Myofascial Release of the Hamstrings Improves Physical Performance—A Study of Young Adults

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 674
Author(s):  
Keisuke Itotani ◽  
Kanta Kawahata ◽  
Wakana Takashima ◽  
Wakana Mita ◽  
Hitomi Minematsu ◽  
...  
Keyword(s):  
Young Adults ◽  
Physical Performance ◽  
Walking Speed ◽  
Quadriceps Muscle ◽  
Lower Limbs ◽  
Joint Movement ◽  
Myofascial Release ◽  
Functional Reach Test ◽  
Hamstring Flexibility ◽  
Walking Speeds

Physical performance is mainly assessed in terms of gait speed, chair rise capacity, and balance skills, and assessments are often carried out on the lower limbs. Such physical performance is largely influenced by the strength of the quadriceps and hamstrings muscles. Flexibility of the hamstrings is important because quadriceps muscle activity influences the hip flexion angle. Therefore, hamstring flexibility is essential to improve physical performance. In this study, Myofascial Release (MFR) was applied to the hamstrings to evaluate its effects. MFR on the hamstrings was performed on 17 young adults. Physical function and physical performance were measured before, immediately after, and 5 days after the MFR intervention: finger floor distance (FFD), range of motion (ROM) of the straight leg raising test (SLR), standing long jump (SLJ), squat jump (SJ), functional reach test (FRT), comfortable walking speeds (C-walking speed), and maximum walking speeds (M-walking speed). The results of the analysis show a significant increase in FFD (−2.6 ± 8.9 vs. 0.4 ± 9.4 vs. 2.4 ± 8.9, p < 0.01), SLJ (185.6 ± 44.5 vs. 185.0 ± 41.8 vs. 196.6 ± 40.1, p < 0.01), and M-walking speed (2.9 ± 0.6 vs. 3.0 ± 0.6 vs. 3.3 ± 0.6, p < 0.01). This study has shown that MFR for hamstrings not only improves flexibility but also increases M-walking speed and physical performance of the SLJ. As MFR is safe and does not involve joint movement, it may be useful for maintaining and improving performance and flexibility during inactivity and for stretching before exercise.

Research Commentary: Analysis of Curriculum Standards: An Important Research Area

2016 ◽  
Vol 47 (2) ◽  
pp. 118-133 ◽  
Author(s):  
Dung Tran ◽  
Barbara J. Reys ◽  
Dawn Teuscher ◽  
Shannon Dingman ◽  
Lisa Kasmer
Keyword(s):  
Mathematics Education ◽  
Education Reform ◽  
Careful Analysis ◽  
Research Area ◽  
State Standards ◽  
Content Standards ◽  
Curriculum Standards ◽  
Education Professionals ◽  
Important Research Area ◽  
Improving Student Learning

This commentary highlights the contribution that careful and systematic analyses of curriculum or content standards can make to questions and issues important in the mathematics education field. We note the increased role that curriculum standards have played as part of a standards-based education reform strategy. We also review different methods used by researchers to compare and analyze the Common Core State Standards for Mathematics, each method designed for a particular purpose. Finally, we call upon mathematics education researchers to engage in careful analysis of curriculum standards and to share their findings in ways that can inform public debate as well as support education professionals in improving student learning opportunities.

scholarly journals On the Analysis of PM/FM Noise Radar Waveforms Considering Modulating Signals with Varied Stochastic Properties

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1727
Author(s):  
Leandro Pralon ◽  
Gabriel Beltrao ◽  
Alisson Barreto ◽  
Bruno Cosenza
Keyword(s):  
Random Phase ◽  
Research Area ◽  
General Term ◽  
Radar Systems ◽  
Noise Radar ◽  
Random Samples ◽  
Spectrum Density ◽  
Important Research Area ◽  
Radar Waveforms ◽  
Stochastic Properties

Noise Radar technology is the general term used to describe radar systems that employ realizations of a given stochastic process as transmit waveforms. Originally, carriers modulated in amplitude by a Gaussian random signal, derived from a hardware noise source, were taken into consideration, justifying the adopted nomenclature. With the advances made in hardware as well as the rise of the software defined noise radar concept, waveform design emerges as an important research area related to such systems. The possibility of generating signals with varied stochastic properties increased the potential in achieving systems with enhanced performances. The characterization of random phase and frequency modulated waveforms (more suitable for several applications) has then gained considerable notoriety within the radar community as well. Several optimization algorithms have been proposed in order to conveniently shape both the autocorrelation function of the random samples that comprise the transmit signal, as well as their power spectrum density. Nevertheless, little attention has been driven to properly characterize the stochastic properties of those signals through closed form expressions, jeopardizing the effectiveness of the aforementioned algorithms as well as their reproducibility. Within this context, this paper investigates the performance of several random phase and frequency modulated waveforms, varying the stochastic properties of their modulating signals.

Human Gait Analysis Method Based on Sample Entropy Fusion AlphaPose Algorithm

2021 ◽  
Author(s):  
Xinyu Lv ◽  
Shengying Wang ◽  
Tao Chen ◽  
Jing Zhao ◽  
Desheng Chen ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Sample Entropy ◽  
Human Gait ◽  
Analysis Method ◽  
Human Gait Analysis

Climate change and employment relations

2017 ◽  
Vol 59 (5) ◽  
pp. 670-679 ◽  
Author(s):  
Caleb Goods
Keyword(s):  
Climate Change ◽  
Research Area ◽  
Research Note ◽  
Employment Relations ◽  
Important Research ◽  
Workplace Relations ◽  
Important Research Area

A central, yet overlooked, aspect of contemporary employment relations is the growing impact climate change is having on workplace relations. This research note outlines how climate change and workplace relations are linked, the minimal academic focus this important research area has received and the limited response from employment relations actors to the climate change challenge. Some examples of ‘climate bargaining’ are given to demonstrate both the connection between employment relations and climate change and to provide possible models for meaningfully advancing climate change actions in the workplace.

MULTI-LEVEL DOCUMENT IMAGE SEGMENTATION USING MULTI-LAYER PERCEPTRON AND SUPPORT VECTOR MACHINE

2012 ◽  
Vol 26 (06) ◽  
pp. 1253002 ◽  
Author(s):  
YAN ZHANG ◽  
BIN YU ◽  
HAI-MING GU
Keyword(s):  
Support Vector Machine ◽  
Image Segmentation ◽  
Research Area ◽  
Document Image ◽  
Support Vector ◽  
Multi Layer Perceptron ◽  
Document Image Analysis ◽  
Important Research Area ◽  
Multi Level ◽  
Document Image Segmentation

Document image segmentation is an important research area of document image analysis which classifies the contents of a document image into a set of text and non-text classes. Previous existing methods are often designed to classify text and halftone therefore they perform poorly in classifying graphics, tables and circuit, etc. In this paper, we present a robust multi-level classification method using multi-layer perceptron (MLP) and support vector machine (SVM) to segment the texts from non-texts and thereafter classify them as tables, graphics and halftones. This method outperforms previously existing methods by overcoming various issues associated with the complexity of document images. Experimental results prove the effectiveness of our proposed method. By virtue of our multi-level classification approach, the text components, halftone components, graphic components and table components are accurately classified respectively which would highly improve OCR accuracy to reduce garbage symbols as well as increase compression ratio thereafter simultaneously.

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