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.

Roughness and fractality of fracture surfaces as indicators of mechanical quantities of porous solids

Open Physics ◽  
2011 ◽  
Vol 9 (6) ◽  
Author(s):  
Tomáš Ficker ◽  
Dalibor Martišek
Keyword(s):  
Mechanical Properties ◽  
Fractal Dimension ◽  
Fractal Dimensions ◽  
Point Of View ◽  
Porous Solids ◽  
Surface Parameter ◽  
Cement Pastes ◽  
Fracture Surfaces ◽  
Profile Parameter ◽  
3D Profile

AbstractThe 3D profile surface parameter H q and fractal dimension D were tested as indicators of mechanical properties inferred from fracture surfaces of porous solids. High porous hydrated cement pastes were used as prototypes of porous materials. Both the profile parameter H q and the fractal dimension D showed capability to assess compressive strength from the fracture surfaces of hydrated pastes. From a practical point of view the 3D profile parameter H q seems to be more convenient as an indicator of mechanical properties, as its values suffer much less from statistical scatter than those of fractal dimensions.

scholarly journals Rock Mechanical Property Influenced by Inhomogeneity

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yunliang Tan ◽  
Dongmei Huang ◽  
Ze Zhang
Keyword(s):  
Mechanical Property ◽  
Fractal Dimension ◽  
Rock Type ◽  
Fractal Dimensions ◽  
Rock Material ◽  
The Self ◽  
Self Similarity ◽  
Red Sandstone ◽  
Variation Patterns ◽  
Rock Microstructure

In order to identify the microstructure inhomogeneity influence on rock mechanical property, SEM scanning test and fractal dimension estimation were adopted. The investigations showed that the self-similarity of rock microstructure markedly changes with the scanned microscale. Different rocks behave in different fractal dimension variation patterns with the scanned magnification, so it is conditional to adopt fractal dimension to describe rock material. Grey diabase and black diabase have high suitability; red sandstone has low suitability. The suitability of fractal-dimension-describing method for rocks depends on both investigating scale and rock type. The homogeneities of grey diabase, black diabase, grey sandstone, and red sandstone are 7.8, 5.7, 4.4, and 3.4, separately; their average fractal dimensions of microstructure are 2.06, 2.03, 1.72, and 1.40 correspondingly, so the homogeneity is well consistent with fractal dimension. For rock material, the stronger brittleness is, the less profile fractal dimension is. In a sense, brittleness is an image of rock inhomogeneity in macroscale, while profile fractal dimension is an image of rock inhomogeneity in microscale. To combine the test of brittleness with the estimation of fractal dimension with condition will be an effective approach for understanding rock failure mechanism, patterns, and behaviours.

A Modified Box-Counting Method to Estimate the Fractal Dimensions

2011 ◽  
Vol 58-60 ◽  
pp. 1756-1761 ◽  
Author(s):  
Jie Xu ◽  
Giusepe Lacidogna
Keyword(s):  
Fractal Dimension ◽  
Fractal Dimensions ◽  
The Self ◽  
Whole Body ◽  
Counting Method ◽  
Border Effect ◽  
Self Similarity ◽  
Box Counting ◽  
Self Similar ◽  
Box Counting Method

A fractal is a property of self-similarity, each small part of the fractal object is similar to the whole body. The traditional box-counting method (TBCM) to estimate fractal dimension can not reflect the self-similar property of the fractal and leads to two major problems, the border effect and noninteger values of box size. The modified box-counting method (MBCM), proposed in this study, not only eliminate the shortcomings of the TBCM, but also reflects the physical meaning about the self-similar of the fractal. The applications of MBCM shows a good estimation compared with the theoretical ones, which the biggest difference is smaller than 5%.

DEVELOPING A NEW METHOD FOR THE IDENTIFICATION OF MICROORGANISMS FOR THE FOOD INDUSTRY USING THE FRACTAL DIMENSION

Fractals ◽  
1994 ◽  
Vol 02 (03) ◽  
pp. 457-460 ◽  
Author(s):  
OSCAR CASTILLO ◽  
PATRICIA MELIN
Keyword(s):  
Quality Control ◽  
Fractal Dimension ◽  
Food Industry ◽  
Fractal Dimensions ◽  
New Method ◽  
Different Types ◽  
One To One

The fractal dimension can be a useful tool in the identification of microorganisms, because it can be experimentally shown that the colonies of different types of bacteria have different geometrical forms, and as a result of this fact different fractal dimensions. Our method of identification of microorganisms for the food industry, is based on the application of a one to one map between the different types of bacteria and their corresponding fractal dimension. The importance of this new method can be related to the need of making more efficient the task of the quality control lab of the food industry.

scholarly journals Modified Catalysts and Their Fractal Properties

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1518
Author(s):  
Gianina Dobrescu ◽  
Florica Papa ◽  
Razvan State ◽  
Monica Raciulete ◽  
Daniela Berger ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Heterogeneous Catalysis ◽  
Fractal Theory ◽  
Fractal Dimensions ◽  
Active Surface ◽  
Point Of View ◽  
Surface Sites ◽  
Fractal Properties ◽  
Active Surface Sites ◽  
Scientific Results

Obtaining high-area catalysts is in demand in heterogeneous catalysis as it influences the ratio between the number of active surface sites and the number of total surface sites of the catalysts. From this point of view, fractal theory seems to be a suitable instrument to characterize catalysts’ surfaces. Moreover, catalysts with higher fractal dimensions will perform better in catalytic reactions. Modifying catalysts to increase their fractal dimension is a constant concern in heterogeneous catalysis. In this paper, scientific results related to oxide catalysts, such as lanthanum cobaltites and ferrites with perovskite structure, and nanoparticle catalysts (such as Pt, Rh, Pt-Cu, etc.) will be reviewed, emphasizing their fractal properties and the influence of their modification on both fractal and catalytic properties. Some of the methods used to compute the fractal dimension of the catalysts (micrograph fractal analysis and the adsorption isotherm method) and the computed fractal dimensions will be presented and discussed.

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.

scholarly journals PENDETEKSIAN CITRA DAUN TANAMAN MENGGUNAKAN METODE BOX COUNTING

2020 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Novita Anggraini Juwitarty ◽  
Kosala Dwidja Purnomo ◽  
Kiswara Agung Santoso
Keyword(s):  
Fractal Dimension ◽  
Fractal Dimensions ◽  
Plant Leaves ◽  
Counting Method ◽  
Image Detection ◽  
Box Counting ◽  
Irregular Shapes ◽  
Different Types ◽  
Box Counting Method ◽  
Leaf Part

Different types of plants make identification difficult. Therefore, we need a system that can identify the similarity of the leaves based on a reference leaf. Extraction can be done by taking one part of the plant and the most easily obtained part is the leaf part. Natural objects such as leaves have irregular shapes and are difficult to measure, but this can be overcome by using fractal dimensions. In this research, image detection of plant leaves will be carried out using the box counting method. The box counting method is a method of calculating fractal dimensions by dividing images into small boxes in various sizes. Image detection using fractal dimension values, we know which leaves the match with the reference. In this study,10 species of leave were tested, with each species 10 samples of plant leaves. Image testing of plant leaves uses a variety of r box size, namely 1/2 ,1/4 , 1/8 , 1/16 ,1/32 , 1/64 , 128which obtain an average match accuracy of 44%. Keywords: Box Counting, Fractal dimension

Simulating Self-Regeneration and Self-Replication Processes Using Movable Cellular Automata with a Mutual Equilibrium Neighborhood

2020 ◽  
Vol 29 (4) ◽  
pp. 741-757
Author(s):  
Kateryna Hazdiuk ◽  
◽  
Volodymyr Zhikharevich ◽  
Serhiy Ostapov ◽  
◽  
...  
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Three Dimensional ◽  
Computer Models ◽  
The Self ◽  
Model Construction ◽  
Natural Phenomena ◽  
Different Types ◽  
Movable Cellular Automata ◽  
Self Replication

This paper deals with the issue of model construction of the self-regeneration and self-replication processes using movable cellular automata (MCAs). The rules of cellular automaton (CA) interactions are found according to the concept of equilibrium neighborhood. The method is implemented by establishing these rules between different types of cellular automata (CAs). Several models for two- and three-dimensional cases are described, which depict both stable and unstable structures. As a result, computer models imitating such natural phenomena as self-replication and self-regeneration are obtained and graphically presented.

Decorative motifs on oil lamps from Grimm's 1973 excavations in Alexandria

2019 ◽  
Author(s):  
Heba Abdel Wahed Sayed
Keyword(s):  
Point Of View ◽  
Symbolic Meaning ◽  
Ancient History ◽  
Different Types ◽  
Decorative Motifs ◽  
Egyptian Culture ◽  
Late Roman

A collection of 30 clay oil lamps from Gunther Grimm's excavations in 1973 in the Western necropolis of Alexandria has been classified by Safaa Samir Abu Al Yazid from Tanta University and found to represent 12 different types ranging in time from the Hellenistic to the late Roman periods in Egypt's ancient history. The present paper looks at this collection from the point of view of the symbolic significance of the decorative motifs used in their decoration. These motifs— figural, floral and geometric—had obvious symbolic meaning to their users and signified more than a simple belief in certain deities. They also reflected Roman Egyptian culture.

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