DECODING OF HAND GESTURES BY FRACTAL ANALYSIS OF ELECTROMYOGRAPHY (EMG) SIGNAL

Fractals ◽  
2019 ◽  
Vol 27 (03) ◽  
pp. 1950022 ◽  
Author(s):  
HAMIDREZA NAMAZI
Keyword(s):  
Fractal Dimension ◽  
Fractal Analysis ◽  
Complex Structure ◽  
Fractal Dimensions ◽  
Major Research ◽  
Hand Gestures ◽  
Research Areas ◽  
Emg Signal ◽  
Human Movements ◽  
Different Types

One of the major research areas in analysis of human movements is to investigate how different movements are related to biosignals. Hand gestures belong to major movements of human that have been considered widely by researchers. Therefore, decoding of different hand’s gestures by analysis of related biosignal is very important to be considered. In this paper, we analyze the complex structure of electromyography (EMG) signal from subjects who did eight hand gestures. For this purpose, we chose fractal dimension as the indicator of complexity. The analysis showed that the EMG signal has the greatest and lowest fractal dimensions in case of fingers flexed together in fist, and pointing index, respectively. The employed method in this research is not limited to the analysis of the influence of hand’s gestures on EMG signal. However, it can be widely applied to analyze the influence of different types of stimuli on different human’s biosignals.

DECODING OF SIMPLE HAND MOVEMENTS BY FRACTAL ANALYSIS OF ELECTROMYOGRAPHY (EMG) SIGNAL

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950042 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
SAJAD JAFARI
Keyword(s):  
Fractal Dimension ◽  
Fractal Analysis ◽  
Complexity Analysis ◽  
Body Movement ◽  
Hand Movement ◽  
Hand Movements ◽  
Heavy Load ◽  
Emg Signal ◽  
Rehabilitation Science ◽  
Different Types

Analysis of body movement is the most important aspect of rehabilitation science. Hand movement as one of the major movements of humans has aroused the attention of many researchers. For this purpose, decoding of movements by analysis of the related bio signals is very important. In this research, complexity analysis of Electromyography (EMG) signal that was recorded due to simple hand movements is done. For this purpose, we employ fractal dimension as the indicator of complexity of signal in this research. The EMG signal was recorded from subjects while they did six simple hand movements and accordingly we applied fractal analysis on the signal. The result of our analysis showed that the EMG signal has the greatest and lowest fractal dimension in case of lateral (for holding thin, flat objects) and hook (for supporting a heavy load) hand movements. The capability seen in this research can be applied to the analysis of other types of bio signals in order to investigate the reaction of humans to different types of stimuli.

Complexity-Based Analysis of the Relation between Human Muscle Reaction and Walking Path

2020 ◽  
Vol 19 (03) ◽  
pp. 2050025 ◽  
Author(s):  
Shahul Mujib Kamal ◽  
Sue Sim ◽  
Rui Tee ◽  
Visvamba Nathan ◽  
Hamidreza Namazi
Keyword(s):  
Fractal Dimension ◽  
Statistical Analysis ◽  
Fractal Theory ◽  
Contact Point ◽  
Fractal Dimensions ◽  
Human Muscle ◽  
Physiological Signals ◽  
Eeg Signal ◽  
Leg Muscles ◽  
Emg Signal

Legs are the contact point of humans during walking. In fact, leg muscles react when we walk in different conditions (such as different speeds and paths). In this research, we analyze how walking path affects leg muscles’ reaction. In fact, we investigate how the complexity of muscle reaction is related to the complexity of path of movement. For this purpose, we employ fractal theory. In the experiment, subjects walk on different paths that have different fractal dimensions and then we calculate the fractal dimension of Electromyography (EMG) signals obtained from both legs. The result of our analysis showed that the complexity of EMG signal increases with the increment of complexity of path of movement. The conducted statistical analysis also supported the result of analysis. The method of analysis used in this research can be further applied to find the relation between complexity of path of movement and other physiological signals of humans such as respiration and Electroencephalography (EEG) signal.

scholarly journals FRACTAL ANALYSIS OF TRABECULAR BONE: A STANDARDISED METHODOLOGY

2011 ◽  
Vol 19 (1) ◽  
pp. 45 ◽  
Author(s):  
Ian Parkinson ◽  
Nick Fazzalari
Keyword(s):  
Fractal Dimension ◽  
Trabecular Bone ◽  
Fractal Analysis ◽  
Fractal Dimensions ◽  
Box Counting ◽  
Cell Tissue ◽  
Image Analyser ◽  
Model Independent ◽  
Box Counting Method ◽  
Image Orientation

A standardised methodology for the fractal analysis of histological sections of trabecular bone has been established. A modified box counting method has been developed for use on a PC based image analyser (Quantimet 500MC, Leica Cambridge). The effect of image analyser settings, magnification, image orientation and threshold levels, was determined. Also, the range of scale over which trabecular bone is effectively fractal was determined and a method formulated to objectively calculate more than one fractal dimension from the modified Richardson plot. The results show that magnification, image orientation and threshold settings have little effect on the estimate of fractal dimension. Trabecular bone has a lower limit below which it is not fractal (λ<25 μm) and the upper limit is 4250 μm. There are three distinct fractal dimensions for trabecular bone (sectional fractals), with magnitudes greater than 1.0 and less than 2.0. It has been shown that trabecular bone is effectively fractal over a defined range of scale. Also, within this range, there is more than 1 fractal dimension, describing spatial structural entities. Fractal analysis is a model independent method for describing a complex multifaceted structure, which can be adapted for the study of other biological systems. This may be at the cell, tissue or organ level and compliments conventional histomorphometric and stereological techniques.

scholarly journals RESEARCH OF THE EMG-SIGNAL USING THE FRACTAL DIMENSION METHOD

2021 ◽  
Vol 1 (1) ◽  
pp. 119-120
Author(s):  
Egor Demidchenko ◽  
Aleksey Pudalov
Keyword(s):  
Fractal Dimension ◽  
Fractal Dimensions ◽  
Human Hand ◽  
Emg Signal

the article deals with the study of EMG signals and their characteristics using the method of fractal dimensions for the task of constructing a database of features that allows you to recognize the movement of the fingers of the human hand.

scholarly journals Fractal analysis of urban catchments and their representation in semi-distributed models: imperviousness and sewer system

2016 ◽  
Author(s):  
Auguste Gires ◽  
Ioulia Tchiguirinskaia ◽  
Daniel Schertzer ◽  
Susana Ochoa Rodriguez ◽  
Patrick Willems ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Fractal Analysis ◽  
Fractal Dimensions ◽  
Hydrological Models ◽  
Scale Invariant ◽  
Sewer System ◽  
Distributed Models ◽  
Urban Catchments ◽  
Distributed Hydrological Models ◽  
Dimension Characteristic

Abstract. Fractal analysis relies on scale invariance and the concept of fractal dimension enables to characterise and quantify the space filled by a geometrical set exhibiting complex and tortuous patterns. Fractal tools have been widely used in hydrology but seldom in the specific context of urban hydrology. In this paper fractal tools are used to analyse surface and sewer data from 10 urban or peri-urban catchments located in 5 European countries. The aim was to characterise urban catchment properties accounting for the complexity and inhomogeneity typical of urban water systems. Sewer system density and imperviousness (roads or buildings), represented in rasterized maps of 2 m × 2 m pixels, were analysed to quantify their fractal dimension, characteristic of scaling invariance. The results showed that both sewer density and imperviousness exhibit scale invariant features and can be characterized with the help of fractal dimensions ranging from 1.6 to 2, depending on the catchment. In a given area consistent results were found for the two geometrical features, yielding a robust and innovative way of quantifying the level of urbanization. The representation of imperviousness in operational semi-distributed hydrological models for these catchments was also investigated by computing fractal dimensions of the geometrical sets made up of the sub-catchments with coefficients of imperviousness greater than a range of thresholds. It enabled to quantify how well spatial structures of imperviousness were represented in the urban hydrological models.

Image Reconstruction and Analysis of Three-Dimensional Fracture Surfaces Based on the Stereo Matching Method

2004 ◽  
Vol 261-263 ◽  
pp. 1593-1598
Author(s):  
M. Tanaka ◽  
Y. Kimura ◽  
A. Kayama ◽  
L. Chouanine ◽  
Reiko Kato ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Image Reconstruction ◽  
Fracture Surface ◽  
Fractal Analysis ◽  
Stereo Matching ◽  
Three Dimensional ◽  
Fractal Dimensions ◽  
Matching Method ◽  
Fracture Surfaces ◽  
Box Counting Method

A computer program of the fractal analysis by the box-counting method was developed for the estimation of the fractal dimension of the three-dimensional fracture surface reconstructed by the stereo matching method. The image reconstruction and fractal analysis were then made on the fracture surfaces of materials created by different mechanisms. There was a correlation between the fractal dimension of the three-dimensional fracture surface and the fractal dimensions evaluated by other methods on ceramics and metals. The effects of microstructures on the fractal dimension were also experimentally discussed.

FRACTAL ANALYSIS OF DENDRITIC ARBORISATION PATTERNS OF STALKED AND ISLET NEURONS IN SUBSTANTIA GELATINOSA OF DIFFERENT SPECIES

Fractals ◽  
2007 ◽  
Vol 15 (01) ◽  
pp. 1-7 ◽  
Author(s):  
NEBOJŠA T. MILOŠEVIĆ ◽  
DUŠAN RISTANOVIĆ ◽  
JOVAN B. STANKOVIĆ ◽  
RADMILA GUDOVIĆ
Keyword(s):  
Fractal Dimension ◽  
Fractal Analysis ◽  
Islet Cells ◽  
Fractal Dimensions ◽  
Substantia Gelatinosa ◽  
Neuronal Populations ◽  
Box Counting ◽  
Morphological Descriptor ◽  
The Mean ◽  
Box Counting Method

Through analysis of the morphology of dendritic arborisation of neurons from the substantia gelatinosa of dorsal horns from four different species, we have established that two types of cells (stalked and islet) are always present. The aim of the study was to perform the intra- and/or inter-species comparison of these two neuronal populations by fractal analysis, as well as to clarify the importance of the fractal dimension as an objective and usable morphological parameter. Fractal analysis was carried out adopting the box-counting method. We have shown that the mean fractal dimensions for the stalked cells are significantly different between species. The same is true for the mean fractal dimensions of the islet cells. Still, no significant differences were found for the fractal dimensions of the stalked and islet cells within a particular species. The human species has shown as the only exception where fractal dimensions of these two types of cells differ significantly. This study shows once more that the fractal dimension is a useful and sensitive morphological descriptor of neuronal structures and differences between them.

Fractal analysis of leaf shapes

1986 ◽  
Vol 16 (1) ◽  
pp. 124-127 ◽  
Author(s):  
J. Vlcek ◽  
E. Cheung
Keyword(s):  
Fractal Dimension ◽  
Fractal Analysis ◽  
Sugar Maple ◽  
Shape Change ◽  
Leaf Shape ◽  
Fractal Dimensions ◽  
Imaging Method ◽  
Analysis Program ◽  
White Oak ◽  
Starting Position

An application of fractal mathematics to the analysis of leaf shapes is presented. Six leaves randomly selected from nine tree species were used in the study. A video imaging method together with microcomputer-based image processing was used to generate leaf outlines. A fractal analysis program was written to calculate the fractal dimensions of the leaves. Recalling a leaf outline from a diskette and specifying both the starting position on it (e.g., the beginning of the petiole) and six step lengths (explained later), the program then generates the fractal dimension according to the theory described. The results show that the fractal dimension is sensitive to leaf shape variations within a species. For example, two types of ginkgo leaves (one with and one without a notch in the middle of the leaf outline) showed distinctly different fractal values. Similar sensitivity to shape change was observed among the leaves of white oak, red oak, and sugar maple where such variables as width to length ratio and the degree of jaggedness of the leaf caused a departure of the fractal value from the average.

scholarly journals Fractal Analysis of Fragmentation Distribution of Rockbursts Induced by Low-Frequency Seismic Disturbances

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Lihua Hu ◽  
Zhenghu Zhang ◽  
Xin Liang ◽  
Chunan Tang
Keyword(s):  
Fractal Dimension ◽  
Low Frequency ◽  
Fractal Dimensions ◽  
Point Of View ◽  
The Self ◽  
Deep Excavation ◽  
Linear Processes ◽  
True Triaxial ◽  
Amplitude Increase ◽  
Different Types

Low-frequency seismic disturbances frequently induce violent rockburst hazards, seriously threatening the safety of deep excavation and mining engineering. To investigate the characteristics and mechanisms of rockbursts induced by seismic disturbances, in this study a series of true triaxial experiments, including the moderate seismically induced, the weak seismically induced, and the self-initiated rockburst experiments under different conditions were conducted. The fractal geometry theory was applied to study rockbursts and the fractal dimensions of fragmentation distribution of different types of rockbursts were calculated. The results show that the fragmentation distributions of both the seismically induced and self-initiated rockbursts exhibit fractal behaviors. For the moderate seismically induced rockbursts, as the static stresses (i.e., the maximum and minimum static stresses) and disturbance amplitude increase, the fractal dimension increases, whereas, as the disturbance frequency increases, the fractal dimension decreases first and then increases. Under similar static loading conditions, the moderate seismically induced rockbursts have the largest fractal dimension, followed by the self-initiated rockbursts, and the weak seismically induced rockbursts have the smallest fractal dimension. There is a linear relationship between the average fractal dimension and kinetic energy of these rockbursts, implying that the fractal dimension can serve as an indicator for estimating rockburst intensity. Furthermore, from a fractal point of view, the energy input, dissipation, and release of these rockbursts are all linear processes.

scholarly journals Bi-Fractal Characterization of the Pore Network of Tight Sandstone

2021 ◽  
Vol 9 ◽  
Author(s):  
Zezhang Song ◽  
Junyi Zhao ◽  
Yuanyin Zhang ◽  
Dailin Yang ◽  
Yunlong Wang ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Thin Section ◽  
Fractal Analysis ◽  
Pore Space ◽  
Fractal Dimensions ◽  
Pore Network ◽  
Physical Analysis ◽  
Tight Sandstone ◽  
Gas Bearing

Fluid seepage performance and accumulation in tight sandstone is a critical research topic for in-depth exploration and development, closely related to the heterogeneity of the pore network. The fractal characterization is one of the most compelling and direct ways for quantitative investigation of heterogeneity. However, only one kind of fractal is used in most studies, and the differences and relations between different fractal dimensions are rarely discussed. This paper chose one of the most representative tight sandstone formations in China, the second member of the Xujiahe Formation, as the research object. First, based on physical analysis and XRD analysis, we carried out a qualitative investigation on pore structure utilizing thin-section and scanning electron microscopy. Then, detailed pore structure parameters were obtained using high-pressure mercury intrusion (HPMI). Lastly, we combined two-dimensional fractal analysis on thin-section images and three-dimensional fractal analysis on HPMI data to characterize the pore network heterogeneity quantitatively. The Xu2 tight sandstone is mainly medium- to fine-grained lithic feldspathic sandstone or feldspathic lithic sandstone with low porosity and permeability. Also, the Xujiahe tight sandstone is mainly composed of quartz, feldspar, and clay. The pore types of Xu2 tight sandstones are primarily intergranular pores, micro-fractures, and intra- and intergranular dissolution pores. Moreover, most of the micro-fractures in gas-bearing formation are open-ended, while most are filled by clay minerals in the dry formation. The r50 (median pore radius) is the most sensitive parameter to seepage capability (permeability) and gas-bearing status. The 2D fractal dimension (Ds) of gas-bearing samples is significantly larger than that of dry samples, while the 3D fractal dimension (D1, D2) of gas-bearing samples is lower than that of dry samples. There is a strong negative correlation between D2 and gas-bearing status, permeability, quartz content, and r50, but a positive correlation between Ds and these parameters. D2 represents the heterogeneity of pore space, while the Ds indicates the development of the pore network. Tectonic movements that generate micro-fractures and clay cementation that blocks the seepage channels are the two main controlling factors on fractal dimensions. Combining 2D and 3D fractal analysis could give a more in-depth investigation of pore structure.

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