scholarly journals Morlet Wavelet Analysis of ML ≥ 3 Earthquakes in the Taipei Metropolitan Area

2015 ◽  
Vol 26 (2-1) ◽  
pp. 83 ◽  
Author(s):  
Kou-Cheng Chen ◽  
Jeen-Hwa Wang ◽  
Kwang-Hee Kim ◽  
Win-Gee Huang ◽  
Kao-Hao Chang ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
Metropolitan Area ◽  
Morlet Wavelet

scholarly journals Exploring the Relationship between Rising Temperatures and the Number of Climate-Related Natural Disasters in China

2021 ◽  
Vol 18 (2) ◽  
pp. 745
Author(s):  
Mingan Zhu ◽  
Bihang Fan
Keyword(s):  
Wavelet Analysis ◽  
Natural Disasters ◽  
Natural Disaster ◽  
Temperature Drop ◽  
Morlet Wavelet ◽  
Temperature Cycle ◽  
Cycle Period ◽  
Considerable Influence ◽  
Elasticity Coefficient ◽  
The Relationship

Warming has strongly influenced the quantity and variability of natural disasters around the globe. This study aims to characterize the varying patterns between rising temperatures and climate-related natural disasters in China from 1951 to 2010. We examined the overall trend in the patterns of an 11-year cycle, and climate-related natural disaster responses to periods of rising and dropping temperature. We used Morlet wavelet analysis to determine the length of a temperature cycle period, and the arc elasticity coefficient to assess the number of climate-related natural disasters in response to the changing temperature. We found that: (1) the overall relationship between temperature and the number of climate-related natural disasters was positive; (2) however, on the cycle level, the pattern of climate-related natural disasters was found to be independent of temperature variation; (3) on the rise-drop level, temperature increases were associated with declines in the number of climate-related natural disasters. Moreover, as temperature decreased, the number of climate-related natural disasters increased substantially, such that temperature had a more considerable influence on the quantity of climate-related natural disasters during the temperature-drop period. Findings in this study can help enhance the dissemination of warning and mitigation efforts to combat natural disasters in the changing climate.

scholarly journals Analysis of Agile Canine Gait Characteristics Using Accelerometry

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4379 ◽  
Author(s):  
Hasti Hayati ◽  
Fatemeh Mahdavi ◽  
David Eager
Keyword(s):  
Wavelet Analysis ◽  
Morlet Wavelet ◽  
Frame Rate ◽  
High Rate ◽  
Measurement Unit ◽  
Contributing Factors ◽  
Severe Injuries ◽  
Speed Reduction ◽  
Morlet Wavelet Transform ◽  
The Time Domain

The high rate of severe injuries associated with racing greyhounds poses a significant problem for both animal welfare and the racing industry. Using accelerometry to develop a better understanding of the complex gait of these agile canines may help to eliminate injury contributing factors. This study used a single Inertial Measurement Unit (IMU) equipped with a tri-axial accelerometer to characterise the galloping of thirty-one greyhounds on five different race tracks. The dorsal-ventral and anterior-posterior accelerations were analysed in both the time and frequency domains. The fast Fourier transform (FFT) and Morlet wavelet transform were applied to signals. The time-domain signals were synced with the corresponding high frame rate videos of the race. It was observed that the acceleration peaks in the dorsal-ventral accelerations correspond to the hind-leg strikes which were noted to be fifteen times the greyhound’s weight. The FFT analysis showed that the stride frequencies in all tracks were around 3.5 Hz. The Morlet wavelet analysis also showed a reduction in both the frequency and magnitude of signals, which suggests a speed reduction throughout the race. Also, by detecting abrupt changes along the track, the wavelet analysis highlighted potentially hazardous locations on the track. In conclusion, the methods applied in this research contribute to animal safety and welfare by eliminating the factors leading to injuries through optimising the track design and surface type.

scholarly journals Characterization of Monsoonal Rainfall in the Sudano-Sahelian Zone of Northwestern Nigeria

2021 ◽  
Vol 1 (2) ◽  
pp. 123-135
Author(s):  
Abdullahi Umar ◽  
Saadu Umar Wali ◽  
Ibrahim Mustapha Dankani
Keyword(s):  
Wavelet Transform ◽  
Wavelet Analysis ◽  
Daily Rainfall ◽  
Kendall Test ◽  
Morlet Wavelet ◽  
Rainfall Data ◽  
Seasonal Rainfall ◽  
Rainfall Characteristics ◽  
Sahelian Zone

Wavelet transform has been underutilized in characterization of rainfall (Real Onset Dates and Real Cessation Dates) in the study area. This study aims at the characterization of monsoonal rainfall. Daily rainfall data of four stations for the period 1981-2018 were collected from Nigerian Meteorological Agency. The Intra-seasonal Rainfall Monitoring Index (IRMI) was generated and used in determining the RODs and RCDs. The Mann–Kendall test was used to detect trends of the rainfall characteristics. Wavelet transform was used in modelling RODs and RCDs. Findings revealed that RODs vary between stations. There is low (0.3 Spearman’s Rank r) correlation between latitudes and Early Cessations (ECs) of rains. The Morlet wavelet analysis revealed that from 1999 to 2018, there were more of EOs and NOs especially in Kano station. We conclude that from 1981 to 2018 there has been a minimal increase in the retreat dates of rainfall in the study area.

scholarly journals Identification of solar periodicities in southern African baobab δ13C record

2020 ◽  
Vol 116 (7/8) ◽  
Author(s):  
Pieter B. Kotze
Keyword(s):  
South Africa ◽  
Spectral Analysis ◽  
Wavelet Analysis ◽  
Maximum Entropy ◽  
Carbon Isotope ◽  
Confidence Level ◽  
Morlet Wavelet ◽  
Sunspot Minimum ◽  
Annual Carbon ◽  
Schwabe Cycle

Spectral analysis using wavelet, Lomb–Scargle and maximum entropy techniques of the proxy rainfall record of northeastern South Africa based on annual carbon isotope (δ13C) data obtained from baobab trees for the period 1600 AD – 2000 AD show clear evidence of the presence of characteristic solar periodicities. Solar periodicities that were identified above the 95% confidence level include the ~11-year Schwabe cycle, the ~22-year Hale cycle as well as the 80–110-year Gleissberg cycle. A Morlet wavelet analysis of the δ13C data between 1600 AD and 1700 AD shows the effect of the Maunder sunspot minimum on both the Schwabe and Hale cycles during this time.

Simulation and Test of the Balance Ability for the Elderly Based on Morlet Wavelet Analysis

2019 ◽  
Author(s):  
Guoquan Liu ◽  
Yuezhong Li ◽  
Yiming Chen ◽  
Zehui Lin ◽  
Xinyi Zheng ◽  
...  
Keyword(s):  
Wavelet Analysis ◽  
The Elderly ◽  
Morlet Wavelet ◽  
Balance Ability

scholarly journals Wavelet analysis on transient behaviour of tidal amplitude fluctuations observed by meteor radar in the lower thermosphere above Bulgaria

2000 ◽  
Vol 18 (3) ◽  
pp. 316-331 ◽  
Author(s):  
D. Pancheva ◽  
P. Mukhtarov
Keyword(s):  
Wavelet Transform ◽  
Wavelet Analysis ◽  
Morlet Wavelet ◽  
Neutral Wind ◽  
Bispectral Analysis ◽  
Time Intervals ◽  
Cross Wavelet Analysis ◽  
Morlet Wavelet Transform ◽  
Cross Wavelet ◽  
Mlt Region

Abstract. On the basis of bispectral analysis applied to the hourly data set of neutral wind measured by meteor radar in the MLT region above Bulgaria it was demonstrated that nonlinear processes are frequently and regularly acting in the mesopause region. They contribute significantly to the short-term tidal variability and are apparently responsible for the observed complicated behavior of the tidal characteristics. A Morlet wavelet transform is proposed as a technique for studying nonstationary signals. By simulated data it was revealed that the Morlet wavelet transform is especially convenient for analyzing signals with: (1) a wide range of dominant frequencies which are localized in different time intervals; (2) amplitude and frequency modulated spectral components, and (3) singular, wave-like events, observed in the neutral wind of the MLT region and connected mainly with large-scale disturbances propagated from below. By applying a Morlet wavelet transform to the hourly values of the amplitudes of diurnal and semidiurnal tides the basic oscillations with periods of planetary waves (1.5-20 days), as well as their development in time, are obtained. A cross-wavelet analysis is used to clarify the relation between the tidal and mean neutral wind variability. The results of bispectral analysis indicate which planetary waves participated in the nonlinear coupling with the atmospheric tides, while the results of cross-wavelet analysis outline their time intervals if these interactions are local.Key words: Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides) - Radio science (nonlinear phenomena)

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