Fractals最新文献_第2页

QUANTIFYING THE COVID-19 SHOCK IN CRYPTOCURRENCIES 量化加密货币中的 covid-19 冲击

Fractals Pub Date : 2024-01-18 DOI: 10.1142/s0218348x24500191

L. H. Fernandes, J. W. Silva, Fernando H. A. Araujo, A. F. Bariviera

{"title":"QUANTIFYING THE COVID-19 SHOCK IN CRYPTOCURRENCIES","authors":"L. H. Fernandes, J. W. Silva, Fernando H. A. Araujo, A. F. Bariviera","doi":"10.1142/s0218348x24500191","DOIUrl":"https://doi.org/10.1142/s0218348x24500191","url":null,"abstract":"This paper sheds light on the changes suffered in cryptocurrencies due to the COVID-19 shock through a nonlinear cross-correlations and similarity perspective. We have collected daily price and volume data for the seven largest cryptocurrencies considering trade volume and market capitalization. For both attributes (price and volume), we calculate their volatility and compute the Multifractal Detrended Cross-Correlations (MF-DCCA) to estimate the complexity parameters that describe the degree of multifractality of the underlying process. We detect (before and during COVID-19) a standard multifractal behavior for these volatility time series pairs and an overall persistent long-term correlation. However, multifractality for price volatility time series pairs displays more persistent behavior than the volume volatility time series pairs. From a financial perspective, it reveals that the volatility time series pairs for the price are marked by an increase in the nonlinear cross-correlations excluding the pair Bitcoin versus Dogecoin [Formula: see text]. At the same time, all volatility time series pairs considering the volume attribute are marked by a decrease in the nonlinear cross-correlations. The K-means technique indicates that these volatility time series for the price attribute were resilient to the shock of COVID-19. While for these volatility time series for the volume attribute, we find that the COVID-19 shock drove changes in cryptocurrency groups.","PeriodicalId":502452,"journal":{"name":"Fractals","volume":"101 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139615752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

VIBRATION ANALYSIS OF HEAVY WEAPONS IN TRANSIT BY AIRCRAFT IN FRACTAL SPACE CONSIDERING LOCATION DEVIATION 考虑位置偏差的飞机运输重型武器在分形空间中的振动分析

Fractals Pub Date : 2024-01-18 DOI: 10.1142/s0218348x2450018x

YONG-GANG Kang, Shuai-Jia Kou, SI-REN Song, YU-ZHEN Chang, AN-YANG Wang, YONG-GANG Chen

{"title":"VIBRATION ANALYSIS OF HEAVY WEAPONS IN TRANSIT BY AIRCRAFT IN FRACTAL SPACE CONSIDERING LOCATION DEVIATION","authors":"YONG-GANG Kang, Shuai-Jia Kou, SI-REN Song, YU-ZHEN Chang, AN-YANG Wang, YONG-GANG Chen","doi":"10.1142/s0218348x2450018x","DOIUrl":"https://doi.org/10.1142/s0218348x2450018x","url":null,"abstract":"Air transportation constitutes a significant advancement in enhancing transportation efficiency. Nonetheless, when this modality is employed for the transit of large-scale armaments and equipment, the vibrational properties of these items within the aircraft’s cabin, coupled with potential deviations from their designated installation positions, emerge as critical factors that could compromise the safety of such transportation endeavors. To accommodate the unique environmental conditions of low-temperature and low-pressure prevalent in high-altitude air transportation, this model employs a fractal frequency formula for an expedited and accurate characterization of vibrational properties, while also providing a detailed analysis of the errors attributable to positional deviations in these vibration assessments. The findings of this research demonstrate that the computational accuracy achieved herein surpasses that of the variational iteration method (VIM) and the homotopy perturbation method (HPM). Moreover, the investigation into the damping effects of inertial forces within fractal dimensions unveils innovative prospects for optimizing nonlinear vibration systems under the challenging conditions of low-temperature and low-pressure environments.","PeriodicalId":502452,"journal":{"name":"Fractals","volume":"116 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139614964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fractal study on interporosity flow function and shape factor of a power-law fluid in rough fractured dual media 粗糙断裂双介质中幂律流体的孔间流函数和形状因子的分形研究

Fractals Pub Date : 2023-11-30 DOI: 10.1142/s0218348x24500051

Shanshan Yang, Ruike Cui, Mingqing Zou, Qiong Sheng, Shuaiyin Chen, Mengying Wang

引用次数: 0

Neural network method for parameter estimation of fractional discrete-time unified systems 分数离散时间统一系统参数估计的神经网络方法

Fractals Pub Date : 2023-11-30 DOI: 10.1142/s0218348x2450004x

Zhifeng Wu, Guo-Cheng Wu, Wei Zhu

引用次数: 0

Complexity-based analysis of the correlation of brain and heart activity in younger and older subjects 基于复杂性的年轻和年长受试者大脑和心脏活动相关性分析

Fractals Pub Date : 2023-11-30 DOI: 10.1142/s0218348x24500142

Najmeh Pakniyat, Gayathri Vivekanandhan, Norazryana Mat Dawi, Ondrej Krejcar, R. Frischer, H. Namazi