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Dense Fractal Networks, Trends, Noises and Switches in Homeostasis Regulation of Shannon Entropy for Chromosomes’ Activity in Living Cells for Medical Diagnostics
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作者 Nikolay E. Galich 《Applied Mathematics》 2013年第11期30-41,共12页
We analyze correlations and patterns of oxidative activity of 3D DNA at DNA fluorescence in complete sets of chromosomes in neutrophils of peripheral blood. Fluorescence of DNA is registered by method of flow cytometr... We analyze correlations and patterns of oxidative activity of 3D DNA at DNA fluorescence in complete sets of chromosomes in neutrophils of peripheral blood. Fluorescence of DNA is registered by method of flow cytometry with nanometer spatial resolution. Experimental data present fluorescence of many ten thousands of cells, from different parts of body in each population, in various blood samples. Data is presented in histograms as frequency distributions of flashes in the dependence on their intensity. Normalized frequency distribution of information in these histograms is used as probabilistic measure for definition of Shannon entropy. Data analysis shows that for this measure of Shannon entropy common sum of entropy, i.e. total entropy E, for any histogram is invariant and has identical trends of changes all values of E (r) = lnr at reduction of rank r of histogram. This invariance reflects informational homeostasis of chromosomes activity inside cells in multi-scale networks of entropy, for varied ranks r. Shannon entropy in multi-scale DNA networks has much more dense packing of correlations than in “small world” networks. As the rule, networks of entropy differ by the mix of normal D 2 and abnormal D > 2 fractal dimensions for varied ranks r, the new types of fractal patterns and hinges for various topology (fractal dimension) at different states of health. We show that all distributions of information entropy are divided on three classes, which associated in diagnostics with a good health or dominants of autoimmune or inflammatory diseases. This classification based on switching of stability at transcritical bifurcation in homeostasis regulation. We defined many ways for homeostasis regulation, coincidences and switching patterns in branching sequences, the averages of H&ouml;lder for deviations of entropy from homeostasis at different states of health, with various saturation levels the noises of entropy at activity of all chromosomes in support regulation of homeostasis. 展开更多
关键词 Abnormal fractals DNA ACTIVITY and Shannon Information ENTROPY fractal Patterns and Fragmentation Informational HOMEOSTASIS Saturations of CHROMOSOMAL Correlations Multi-Scale fractal networkS of Shannon ENTROPY
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Fractal Networks of Real Worlds of Fluorescing DNA in Complete Set of Chromosomes inside Blood Cells for Medical Diagnostics
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作者 Nikolay E. Galich 《Open Journal of Biophysics》 2013年第4期232-244,共13页
We analyze fluorescence due to oxidizing activity of DNA in neutrophils of peripheral blood in the large populations ~104 - 105 of cells. Fluorescence is registered by flow cytometry method. Spatial resolution is abou... We analyze fluorescence due to oxidizing activity of DNA in neutrophils of peripheral blood in the large populations ~104 - 105 of cells. Fluorescence is registered by flow cytometry method. Spatial resolution is about a few nanometers for varied complex three-dimensional (3D) DNA nanostructures of all non-coding and coding parts of DNA. It’s shown that oxidative activity of all 3D DNA in the full set of chromosomes inside cells is defined by new standards for complex networks of “exponentially small worlds”, with more dense packing than in the well known networks of “small worlds”. Analysis of various blood samples in vivo and during medical treatment shown that only two classes of Good and Bad Networks of DNA for a good and a bad health existed. This division is defined by any network to one from two classes of “n” or “s” shaped curves for typical deviations and from straight line in perfect networks of “exponentially small worlds”, as for two types of hysteresis curves at phase transitions or at switching of bistability. These deviations coincide with two types of positive and negative trends of changing fractal dimension by changing the scales of multi-scale networks of fluorescing DNA. These trends give the overall assessments of human immunity, including hidden and unidentified diseases, and as a sum of all kinds of health and illness of given person, from the point of view the inner life of neutrophils, living in different parts of human body in given time. Characteristics of deviations associated with type, level and complexity of illness in the dependence on 展开更多
关键词 Abnormal fractals in DNA ACTIVITY Complex networkS of 3D-DNA Diagnostics and Hysteresis in fractal networkS of DNA DNA Packing networkS of “Exponentially Small Worlds” Shannon-Weaver Biodiversity of DNA ACTIVITY INSIDE Cells
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Research on the Eigentime and Related Problems of theCorresponding Fractal Network of Sierpiński Fractal Antenna
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作者 PENG Yulu HUANG Yuke 《中国应用数学通报》 2025年第2期10-18,共9页
This paper studies the eigentime and related issues in the fractal network corresponding to the Sierpiński fractal antenna.The access time or hitting time H(i,j)is the expected number of steps before node j is visite... This paper studies the eigentime and related issues in the fractal network corresponding to the Sierpiński fractal antenna.The access time or hitting time H(i,j)is the expected number of steps before node j is visited,starting from node i.The eigentime of G is the expectation of H(i,j)for all i,j∈G.Classical eigenvalue method let H(i,i)=0.However,when studying the random walk behavior of electrons in fractal networks corresponding to fractal antennas,it is nec-essary to consider the time when electrons leave a certain node and first return to that node(self return time).This paper adopts two research methods-the eigenvalue method based on spectral theory and the Markov chain method based on stochastic process theory-to obtain the modified in-trinsic time,and demonstrates through an example that the difference between the classical intrin-sic time and the modified intrinsic time is precisely due to the self return time.This paper shows the applications of fractal networks in modern communications.The research results are expected to provide a theoretical basis for the design and performance optimization of fractal antennas. 展开更多
关键词 Sierpiński fractal antenna fractal network random walk eigentime Markov Chain
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Hierarchically structured 2D silver sheets with fractal network 被引量:1
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作者 Aasim Shahzad Suk Ho Bhang +2 位作者 Euiyoung Jung Woo-Sik Kim Taekyung Yu 《Journal of Materiomics》 SCIE EI 2018年第2期121-128,共8页
Oriented attachment can be used as a good synthetic route to make highly anisotropic nanostructures including nanorod,nanowire,nanoplate,and nanosheets.In a typical growth of anisotropic nanostructures,coalescence and... Oriented attachment can be used as a good synthetic route to make highly anisotropic nanostructures including nanorod,nanowire,nanoplate,and nanosheets.In a typical growth of anisotropic nanostructures,coalescence and reshaping after attachment make dense nanostructures.In this report,we show the formation of Ag sheets having fractal network by oriented attachment at low reaction temperature of 30℃.The synthesized Ag sheets exhibited good crystalline nature despite of their network structure and low synthetic temperature.We also investigated the effect of reaction conditions for the formation of the Ag sheets.In addition,using the Ag sheets as a sacrificial template,we could make hollow Au sheets via galvanic replacement. 展开更多
关键词 Ag sheets fractal network Oriented attachment AQUEOUS-PHASE Au sheets Galvanic replacement
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Relationships Between Fractal Road and Drainage Networks in Wuling Mountainous Area:Another Symmetric Understanding of Human-Environment Relations 被引量:2
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作者 LIU Cheng-liang DUAN De-zhong ZHANG Hong 《Journal of Mountain Science》 SCIE CSCD 2014年第4期1060-1069,共10页
Symmetrical relationships between humans and their environment have been referred to as an extension of symmetries in the human geographical system and have drawn great attention.This paper explored the symmetry betwe... Symmetrical relationships between humans and their environment have been referred to as an extension of symmetries in the human geographical system and have drawn great attention.This paper explored the symmetry between physical and human systems through fractal analysis of the road and drainage networks in Wuling mountainous area.We found that both the road and drainage networks reflect weak clustering distributions.The evolution of the road network shared a significant self-organizing composition,while the drainage network showed obvious double fraetal characteristics.The geometric fractal dimension of the road network was larger than that of the drainage network.In addition,when assigned a weight relating to hierarchy or length,neither the road network nor drainage network showed a fractal property.These findings indicated that the fractal evolution of the road network shared certain similarities with fractal distribution of the drainage network.The symmetry between the two systems resulted from an interactive process of destroying symmetry at the lower order and reconstructing symmetry at the higher order.The relationships between the fractal dimensions of the rural-urban road network,the drainage network andthe urban system indicated that the development of this area was to achieve the symmetrical isomorphism of physical-human geographical systems. 展开更多
关键词 fractal road network fractal drainagenetwork SYMMETRY Human-environment relation SELF-ORGANIZATION
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A smart productivity evaluation method for shale gas wells based on 3D fractal fracture network model 被引量:2
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作者 WEI Yunsheng WANG Junlei +4 位作者 YU Wei QI Yadong MIAO Jijun YUAN He LIU Chuxi 《Petroleum Exploration and Development》 CSCD 2021年第4期911-922,共12页
The generation method of three-dimensional fractal discrete fracture network(FDFN)based on multiplicative cascade process was developed.The complex multi-scale fracture system in shale after fracturing was characteriz... The generation method of three-dimensional fractal discrete fracture network(FDFN)based on multiplicative cascade process was developed.The complex multi-scale fracture system in shale after fracturing was characterized by coupling the artificial fracture model and the natural fracture model.Based on an assisted history matching(AHM)using multiple-proxy-based Markov chain Monte Carlo algorithm(MCMC),an embedded discrete fracture modeling(EDFM)incorporated with reservoir simulator was used to predict productivity of shale gas well.When using the natural fracture generation method,the distribution of natural fracture network can be controlled by fractal parameters,and the natural fracture network generated coupling with artificial fractures can characterize the complex system of different-scale fractures in shale after fracturing.The EDFM,with fewer grids and less computation time consumption,can characterize the attributes of natural fractures and artificial fractures flexibly,and simulate the details of mass transfer between matrix cells and fractures while reducing computation significantly.The combination of AMH and EDFM can lower the uncertainty of reservoir and fracture parameters,and realize effective inversion of key reservoir and fracture parameters and the productivity forecast of shale gas wells.Application demonstrates the results from the proposed productivity prediction model integrating FDFN,EDFM and AHM have high credibility. 展开更多
关键词 fractal discrete fracture network multiplicative cascade process embedded discrete fracture model intelligent history matching reservoir parameter inversion shale gas smart productivity evaluation
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Coordination and evolution mechanism of fractal crack network in mining rock mass destruction 被引量:1
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作者 YU Guang-ming~1, ZHANG Chun-hui~2 (1. Qingdao Institute of Architecture and Engineering, Qingdao 266033, China 2. Liaoning Technical University, Fuxin 123000, China) 《中国有色金属学会会刊:英文版》 CSCD 2005年第S1期105-107,共3页
Based on the natural characters of stratum, complicated geological mining conditions and the essence of mining rock mass destruction, the complexity of rock mass destruction caused by miningw as analyzed. The inner li... Based on the natural characters of stratum, complicated geological mining conditions and the essence of mining rock mass destruction, the complexity of rock mass destruction caused by miningw as analyzed. The inner link between rock mass destruction phenomena caused by mining and nonlinear science was revealed. There are numerous cracks in natural rock mass. The cracks’ distribution is irregular and is of statistical fractal structure. Self-organizational nonlinear evolution of the inner structure flaws leads to the rock mass destruction with external force. The evolution includes single fault’s fractal development, formation and evolution of fractal crack network and coordination of fractal crack network, etc. The law of fractal crack network’s evolution was introduced, at the same time, the coordination of fractal crack network was analyzed. Finally, based on coordination the principal equation of mining-caused subsidence of structural rock mass was established and its steady-state solution and unsteady-state solution were found. 展开更多
关键词 the complexity of rock mass DESTRUCTION fractal CRACK network COORDINATION
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Improve Fractal Compression Encoding Speed Using Feature Extraction and Self-organization Network 被引量:1
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作者 Berthe Kya, Yang Yang Information Engineering School. University of Science and Technology Beijing. Beijing 100083. China 《Journal of University of Science and Technology Beijing》 CSCD 2001年第4期306-310,共5页
Image compression consists of two main parts: encoding and decoding. One of the important problems of the fractal theory is the long encoding implementation time, which hindered the acceptance of fractal image compres... Image compression consists of two main parts: encoding and decoding. One of the important problems of the fractal theory is the long encoding implementation time, which hindered the acceptance of fractal image compression as a practical method. The long encoding time results from the need to perform a large number of domain-range matches, the total encoding time is the product of the number of matches and the time to perform each match. In order to improve encoding speed, a hybrid method combining features extraction and self-organization network has been provided, which is based on the feature extraction approach the comparison pixels by pixels between the feature of range blocks and domains blocks. The efficiency of the new method was been proved by examples. 展开更多
关键词 image compression fractal theory features extraction self-organization network fractal encoding
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Study on the phase transition of the fractal scale-free networks
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作者 Qing-Kuan Meng Dong-Tai Feng +4 位作者 Yu-Ping Sun Ai-Ping Zhou Yan Sun Shu-Gang Tan Xu-Tuan Gao 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第10期512-517,共6页
Based on the Ising spin, the phase transition on fractal scale-free networks with tree-like skeletons is studied, where the loops are generated by local links. The degree distribution of the tree-like skeleton satisfi... Based on the Ising spin, the phase transition on fractal scale-free networks with tree-like skeletons is studied, where the loops are generated by local links. The degree distribution of the tree-like skeleton satisfies the power-law form P(k)~ k^-δ.It is found that when δ≥3, the renormalized scale-free network will have the same degree distribution as the original network. For a special case of δ = 4.5, a ferromagnetic to paramagnetic transition is found and the critical temperature is determined by the box-covering renormalization method. By keeping the structure of the fractal scale-free network constant, the numerical relationship between the critical temperature and the network size is found, which is the form of power law. 展开更多
关键词 fractal scale-free network phase transition RENORMALIZATION
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Fractal Analysis of Mobile Social Networks
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作者 郑巍 潘倩 +3 位作者 孙晨 邓宇凡 赵小康 康钊 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第3期142-145,共4页
Fractal and self similarity of complex networks have attracted much attention in recent years. The fractal dimension is a useful method to describe the fractal property of networks. However, the fractal features of mo... Fractal and self similarity of complex networks have attracted much attention in recent years. The fractal dimension is a useful method to describe the fractal property of networks. However, the fractal features of mobile social networks (MSNs) are inadequately investigated. In this work, a box-covering method based on the ratio of excluded mass to closeness centrality is presented to investigate the fractal feature of MSNs. Using this method, we find that some MSNs are fractal at different time intervals. Our simulation results indicate that the proposed method is available for analyzing the fractal property of MSNs. 展开更多
关键词 of MSNs fractal Analysis of Mobile Social networks in IS NODE
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Performance-based fractal fracture model for complex fracture network simulation 被引量:2
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作者 Wen-Dong Wang Yu-Liang Su +2 位作者 Qi Zhang Gang Xiang Shi-Ming Cui 《Petroleum Science》 SCIE CAS CSCD 2018年第1期126-134,共9页
The paper presents a novel hydraulic fracturing model for the characterization and simulation of the complex fracture network in shale gas reservoirs. We go beyond the existing method that uses planar or orthogonal co... The paper presents a novel hydraulic fracturing model for the characterization and simulation of the complex fracture network in shale gas reservoirs. We go beyond the existing method that uses planar or orthogonal conjugate fractures for representing the ''complexity'' of the network. Bifurcation of fractures is performed utilizing the Lindenmayer system based on fractal geometry to describe the fracture propagation pattern, density and network connectivity. Four controlling parameters are proposed to describe the details of complex fractures and stimulated reservoir volume(SRV). The results show that due to the multilevel feature of fractal fractures, the model could provide a simple method for contributing reservoir volume calibration. The primary-and second-stage fracture networks across the overall SRV are the main contributions to the production, while the induced fracture network just contributes another 20% in the late producing period. We also conduct simulation with respect to different refracturing cases and find that increasing the complexity of the fracture network provides better performance than only enhancing the fracture conductivity. 展开更多
关键词 fractal geometry fractal fracture model Complex fracture network characterization Contributing reservoirvolume REFRACTURING
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MULTISCALE IMAGE SEGMENTATION USING FRACTAL AND NEURAL NETWORK
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作者 Yang Shaoguo Yin Zhongke Luo Bingwei (University of Electronic Science and Technology of China, Chengdu 610054) 《Journal of Electronics(China)》 1999年第4期299-304,共6页
Clustering algorithms in feature space are important methods in image segmentation. The choice of the effective feature parameters and the construction of the clustering method are key problems encountered with cluste... Clustering algorithms in feature space are important methods in image segmentation. The choice of the effective feature parameters and the construction of the clustering method are key problems encountered with clustering algorithms. In this paper, the multifractal dimensions are chosen as the segmentation feature parameters which are extracted from original image and wavelet-transformed image. SOM (Self-Organizing Map) network is applied to cluster the segmentation feature parameters. The experiment shows that the performance of the presented algorithm is very good. 展开更多
关键词 fractal WAVELET TRANSFORM NEURAL network Image SEGMENTATION
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FractalNet-LSTM Model for Time Series Forecasting
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作者 Nataliya Shakhovska Volodymyr Shymanskyi Maksym Prymachenko 《Computers, Materials & Continua》 2025年第3期4469-4484,共16页
Time series forecasting is important in the fields of finance,energy,and meteorology,but traditional methods often fail to cope with the complex nonlinear and nonstationary processes of real data.In this paper,we prop... Time series forecasting is important in the fields of finance,energy,and meteorology,but traditional methods often fail to cope with the complex nonlinear and nonstationary processes of real data.In this paper,we propose the FractalNet-LSTM model,which combines fractal convolutional units with recurrent long short-term memory(LSTM)layers to model time series efficiently.To test the effectiveness of the model,data with complex structures and patterns,in particular,with seasonal and cyclical effects,were used.To better demonstrate the obtained results and the formed conclusions,the model performance was shown on the datasets of electricity consumption,sunspot activity,and Spotify stock price.The result showed that the proposed model outperforms traditional approaches at medium forecasting horizons and demonstrates high accuracy for data with long-term and cyclical dependencies.However,for financial data with high volatility,the model’s efficiency decreases at long forecasting horizons,indicating the need for further adaptation.The findings suggest further adaptation.The findings suggest that integrating fractal properties into neural network architecture improves the accuracy of time series forecasting and can be useful for developing more accurate and reliable forecasting systems in various industries. 展开更多
关键词 Time series fractal neural networks forecasting LSTM fractalNet
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基于EMD和Multi-fractal spectrum的BP水机故障诊断 被引量:5
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作者 薛延刚 《排灌机械工程学报》 EI CSCD 北大核心 2016年第5期455-460,共6页
为了准确判断水轮机组的故障,提高水轮机组诊断的精确性,建立了EMD-Multi-fractal spectrum和改进BP神经网络相结合的机组振动故障诊断模型.选取水轮发电机组不同工况下的轴系正常、轴承油膜涡动、转子部件不平衡、转子不对中等状态,采... 为了准确判断水轮机组的故障,提高水轮机组诊断的精确性,建立了EMD-Multi-fractal spectrum和改进BP神经网络相结合的机组振动故障诊断模型.选取水轮发电机组不同工况下的轴系正常、轴承油膜涡动、转子部件不平衡、转子不对中等状态,采集各状态下的振动信号.经过经验模态分解得到振动信号波各种故障信号的EMD分量,根据信号波形趋势图由EMD系数提取出波形样本,再由多重分形谱算法提取波形样本的特征值alpha(q),f(q),将该特征向量作为BP神经网络的输入进行分类识别.将训练好的神经网络应用于全部样本,得到测试正确率为100%.该模型用波形提取信号特征代替了传统的频谱特性,并结合先进的多重分形谱进行诊断识别,为水轮发电机组故障诊断提供了一种新的思路.应用信号采集于水电厂运行的水轮机,根据诊断的结果对轴系各个部件进行局部校正,通过检测发现振动和摆度都大大减弱.该方法提高了检测精度,增强了人机交互性,具有重要的理论意义和实用价值. 展开更多
关键词 水轮机组 故障诊断 经验模态分解 多重分形谱 BP神经网络
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Fractal Characteristic of Pits Distribution on 304 Stainless Steel Corroded Surface and Its Application in Corrosion Diagnosis 被引量:2
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作者 梁成浩 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2007年第3期389-393,共5页
Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution. Fractal fea... Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution. Fractal features of pits distribution over the corroded surfaces were observed and described by the fractal dimension. A 5-8-2 back-propagation (BP) artificial neural network model for the diagnoses of the pitting corrosion rate and pits deepness of 304 stainless steel under various conditions was developed by considering the fractal dimension as a key parameter for describing the pitting corrosion characteristics. The predicted results are well in agreement with the experimental data of pitting corrosion rate and pit deepness. The max relative errors between their experimental and simulation data are 6.69% and 4.62%, respectively. 展开更多
关键词 304 stainless steel pits distribution fractal neural network DIAGNOSIS
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Evolution of a mining induced fracture network in the overburden strata of an inclined coal seam 被引量:8
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作者 Wei Xiujun Gao Mingzhong +3 位作者 Lv Youchang Shi Xiangchao Gao Hailian Zhou Hongwei 《International Journal of Mining Science and Technology》 SCIE EI 2012年第6期775-779,共5页
The geological conditions of the Pingdingshan coal mining group were used to construct a physical model used to study the distribution and evolution of mining induced cracks in the overburden strata.Digital graphics t... The geological conditions of the Pingdingshan coal mining group were used to construct a physical model used to study the distribution and evolution of mining induced cracks in the overburden strata.Digital graphics technology and fractal theory are introduced to characterize the distribution and growth of the mining induced fractures in the overburden strata of an inclined coal seam.A relationship between fractal dimension of the fracture network and the pressure in the overburden strata is suggested.Mining induced fractures spread dynamically to the mining face and up into the roof as the length of advance increases.Moreover,the fractal dimension of the fracture network increases with increased mining length,in general,but decreases during a period from overburden strata separation until the main roof collapses.It is a1so shown that overburden strata pressure plays an important role in the evolution of mining induced fractures and that the fractal dimension of the fractures increases with the pressure of the overburden. 展开更多
关键词 Inclined coal SEAM Fracture network EVOLUTION fractal DIMENSION
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A fractal-based model for the microstructure evolution of silicon bronze wires fabricated by dieless drawing 被引量:1
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作者 Zhen Wang Xue-feng Liu +1 位作者 Yong He Jian-xin Xie 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第6期770-776,共7页
The back-propagation neural (BPN) network was proposed to model the relationship between the parameters of the dieless draw- ing process and the microstrecmres of the QSi3-1 silicon bronze alloy. Combined with image... The back-propagation neural (BPN) network was proposed to model the relationship between the parameters of the dieless draw- ing process and the microstrecmres of the QSi3-1 silicon bronze alloy. Combined with image processing techniques, grain sizes and grain-boundary morphologies were respectively determined by the quantitative metallographic method and the flactal theory. The outcomes obtained show that the deformed microstructures exhibit typical fractal features, and the boundaries can be characterized quantitatively by ffactal dimensions. With the temperature of 600-800℃ and the drawing speed of 0.67-1.00 mm-s-1, either a lower temperature or a higher speed will cause a smaller grain size together with an elevated fractal dimension. The developed model can be capable for forecasting the microstructure evolution with a minimum error. The average relative errors between the predicted results and the experimental values of grain size and fractal dimension are 3.9% and 0.9%, respectively. 展开更多
关键词 silicon bronze dieless drawing MICROSTRUCTURE fractal dimension neural networks
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Studying Relationships between the Fractal Dimension of the Drainage Basins and Some of Their Geomorphological Characteristics 被引量:2
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作者 Zahra Khanbabaei Amir Karam Ghobad Rostamizad 《International Journal of Geosciences》 2013年第3期636-642,共7页
Complex nonlinear dynamic systems are ubiquitous in the landscapes and phenomena studied by earth sciences in general and by geomorphology in particular. Many natural landscape features have an aspect such as fractals... Complex nonlinear dynamic systems are ubiquitous in the landscapes and phenomena studied by earth sciences in general and by geomorphology in particular. Many natural landscape features have an aspect such as fractals. In the many geomorphologic phenomena such as river networks and coast lines this is visible. In recent years fractal geometry offers as an option for modeling river geometry and physical processes of rivers. The fractal dimension is a statistical quantity that indicates how a fractal scales with the shrink, the space occupied. This theory has the mathematical basis but also applied in geomorphology and also shown great success. Physical behavior of many natural processes as well as using fractal geometry is predictable relations. Behavior of complex natural phenomena as rivers has always been of interest to researchers. In this study using data basic maps, drainage networks map and Digital Elevation Model of the ground was prepared. Then applying the rules Horton-Strahler river network, fractal dimensions were calculated to examine the relationship between fractal dimension and some rivers geomorphic features were investigated. Results showed fractal dimension of watersheds have meaningful relations with factors such as shape form, area, bifurcation ratio and length ratio in the watersheds. 展开更多
关键词 fractal Geometry fractal DIMENSION Drainage networks Horton-Strahler
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Fractal Characteristics and Prediction of Ti-15-3 Alloy Recrystallized Microstructure
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作者 Ping LI Qing ZHANG Kemin XUE 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2008年第6期835-839,共5页
Grain shape of the hot deforming alloy is an important of material. The fractal theory was applied to analyze index to character the microstructure and performance the recrystallized microstructure of Ti-15-3 alloy af... Grain shape of the hot deforming alloy is an important of material. The fractal theory was applied to analyze index to character the microstructure and performance the recrystallized microstructure of Ti-15-3 alloy after hot deformation and solution treatment. The fractal dimensions of recrystallized grains were calculated by slit island method. The influence of processing parameters on fractal dimension and grain size was studied, It has been shown that the shapes of recrystallized grain boundaries are self-similar, and the fractal dimension varies from 1 to 2. With increasing deformation degree and strain rate or decreasing deformation temperature, the fractal dimension of grain boundaries increased and the grain size decreased. So the fractal dimension could characterize the grain shape and size. A neural network model was trained to predict the fractal dimension of recrystallized microstructure and the result is in excellent agreement with the experimental data. 展开更多
关键词 Ti-15-3 alloy Hot deformation Recrystallized microstructure fractal Neural network
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基于VRA-UNet网络的煤岩组合体裂隙识别与三维重构 被引量:3
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作者 王登科 王龙航 +6 位作者 秦亚光 位乐 曹塘根 李文睿 李璐 陈旭 夏玉玲 《煤炭科学技术》 北大核心 2025年第2期96-108,共13页
在煤岩组合体裂隙三维重构中,针对传统阈值分割方法无法准确确定煤岩之间的阈值大小从而导致裂隙分割效果不佳的问题,基于深度学习理论提出了一种新型VRA-UNet煤岩组合体裂隙精确识别模型,为煤岩组合体裂隙精确识别提供了一种优化解决... 在煤岩组合体裂隙三维重构中,针对传统阈值分割方法无法准确确定煤岩之间的阈值大小从而导致裂隙分割效果不佳的问题,基于深度学习理论提出了一种新型VRA-UNet煤岩组合体裂隙精确识别模型,为煤岩组合体裂隙精确识别提供了一种优化解决方案。为了提升模型的泛化能力和防止初始化模型参数过于随机,使用VGG16模块作为骨干特征提取网络。针对煤岩组合体裂隙拓扑结构复杂,非均匀性强等问题,在上采样部分引入使用残差连接且具有空间维度和通道维度的注意力模块(ResCBAM)增强模型特征提取能力,缓解模型梯度消失的问题。在下采样的末端加入了利用不同尺度卷积核的非对称空洞金字塔模块(AC-ASPP),通过多尺度的特征提取,提高模型对不同大小裂隙的识别能力。同时,利用煤岩组合体CT扫描图像数据集验证了模型的有效性。研究结果表明:VRA-UNet模型在裂隙提取和识别方面性能良好,平均交并比、像素平均值及识别精度分别为85.22%、90.80%和91.95%;与主流的分割网络UNet、PSPNet、DeeplabV3+、FCN和SegNet相比,VRA-UNet模型的平均交并比分别提高了6.05%、16.7%、10.77%、6.87%和6.4%,像素平均值分别提高了7.13%、13.29%、12.84%、7.4%和7.53%,识别精度分别提高了3.82%、14.45%、7.4%、5.58%和4.31%;VRA-UNet识别出的裂隙结构分形维数与原始CT扫描裂隙结构分形维数保持了良好的一致性,真实还原了煤岩组合体内部裂隙结构的分布特征。 展开更多
关键词 煤岩组合体 裂隙识别 裂隙重构 卷积神经网络 分形维数
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