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.

An algorithm for Morlet wavelet transform based on generalized discrete Fourier transform

2019 ◽  
Vol 17 (05) ◽  
pp. 1950030
Author(s):  
Hua Yi ◽  
Peichang Ouyang ◽  
Tao Yu ◽  
Tao Zhang
Keyword(s):  
Fourier Transform ◽  
Wavelet Transform ◽  
Discrete Fourier Transform ◽  
Time Domain ◽  
Morlet Wavelet ◽  
Wavelet Function ◽  
Linear Convolution ◽  
Calculation Results ◽  
Morlet Wavelet Transform ◽  
The Time Domain

Continuous wavelet transform (CWT) is a linear convolution of signal and wavelet function for a fixed scale. This paper studies the algorithm of CWT with Morlet wavelet as mother wavelet by using nonzero-padded linear convolution. The time domain filter, which is a non-causal filter, is the sample of wavelet function. By making generalized discrete Fourier transform (GDFT) and inverse transform for this filter, we can get a geometrically weighted periodic extension of the filter when evaluated outside its original support. From this extension of the time domain filter, we can get a causal filter. In this paper, GDFT-based algorithm for CWT, which has a more concise form than that of linear convolution proposed by Jorge Martinez, is constructed by using this causal filter. The analytic expression of the GDFT of this filter, which is essential for GDFT-based algorithm for CWT, is deduced in this paper. The numerical experiments show that the calculation results of GDFT-based algorithm are stable and reliable; the running speed of GDFT-based algorithm is faster than that of the other two algorithms studied in our previous work.

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)

Factors Affecting Driver Injury Severity in the Wrong-Way Crash: Accounting for Potential Heterogeneity in Means and Variances of Random Parameters

2021 ◽  
pp. 036119812110098
Author(s):  
Miao Yu ◽  
Jinxing Shen ◽  
Changxi Ma
Keyword(s):  
High Speed ◽  
Injury Severity ◽  
Unobserved Heterogeneity ◽  
Research Effort ◽  
Random Parameter ◽  
Policy Implications ◽  
Contributing Factors ◽  
Severe Injuries ◽  
Data Set ◽  
Severity Levels

Because of the high percentage of fatalities and severe injuries in wrong-way driving (WWD) crashes, numerous studies have focused on identifying contributing factors to the occurrence of WWD crashes. However, a limited number of research effort has investigated the factors associated with driver injury-severity in WWD crashes. This study intends to bridge the gap using a random parameter logit model with heterogeneity in means and variances approach that can account for the unobserved heterogeneity in the data set. Police-reported crash data collected from 2014 to 2017 in North Carolina are used. Four injury-severity levels are defined: fatal injury, severe injury, possible injury, and no injury. Explanatory variables, including driver characteristics, roadway characteristics, environmental characteristics, and crash characteristics, are used. Estimation results demonstrate that factors, including the involvement of alcohol, rural area, principal arterial, high speed limit (>60 mph), dark-lighted conditions, run-off-road collision, and head-on collision, significantly increase the severity levels in WWD crashes. Several policy implications are designed and recommended based on findings.

339 Morlet wavelet transform in EEG during perceptuo-motor tasks

1998 ◽  
Vol 30 (1-2) ◽  
pp. 131-132
Author(s):  
S. Slobounovl ◽  
R. Tutwiler ◽  
E. Slobounova
Keyword(s):  
Wavelet Transform ◽  
Morlet Wavelet ◽  
Motor Tasks ◽  
Morlet Wavelet Transform

Fall, Crush, Kick: Mechanisms and Outcomes in a Cohort of Equine-Related Injuries

2021 ◽  
pp. 000313482110488
Author(s):  
Pratik Bhade ◽  
Amelia Parsons ◽  
Abbey Smiley ◽  
Jacob Shreffler ◽  
Nick Nash ◽  
...  
Keyword(s):  
Traumatic Injury ◽  
The United States ◽  
Rib Fractures ◽  
High Rate ◽  
Protective Equipment ◽  
Solid Organ ◽  
Mechanism Of Injury ◽  
Severe Injuries ◽  
Protective Devices ◽  
Animal Size

Introduction The potential for significant traumatic injury to individuals who interact with horses remains high due to animal size, forces applied, and unpredictability. Despite an estimated 30 million riders in the United States annually, few recent publications have addressed this patient population. Objectives This study describes characteristics of patients injured in interactions with horses, focusing on mechanism of injury and use of protective equipment. Methods We queried our institution’s trauma registry for all patients admitted for equine-related injuries (ERI) between January 1, 2013 and December 31, 2017. We categorized by specific mechanism of injury (fall, crush, kick, fall + crush, and fall + kick) and presence or absence of protective devices. Results We discovered 143 patients admitted for injuries in equine-related accidents. Patients averaged 49.2 years old, and 62.2% were female. Crush injuries resulted in a high rate of rib fractures. Riders who were kicked had an increased chance of solid organ and facial injuries and falls most commonly led to rib fractures and extremity trauma. Despite lack of documentation on most subjects, protective devices were associated with less severe injuries in those with data (n = 36). Conclusions In this relatively large series of patients with ERI, we found mechanism differences within injury groups. Providers should more carefully document specific circumstances of ERIs. All individuals working with or around horses should exercise prudence and consider using protective equipment.

Victimization and Substance Abuse among Women: Contributing Factors, Interventions, and Implications

2002 ◽  
Vol 6 (4) ◽  
pp. 325-397 ◽  
Author(s):  
TK Logan ◽  
Robert Walker ◽  
Jennifer Cole ◽  
Carl Leukefeld
Keyword(s):  
Substance Abuse ◽  
High Rate ◽  
Clinical Implications ◽  
Contributing Factors ◽  
Research Results ◽  
Treatment Models

Although the literature indicates that there is an association of victimization with substance abuse, there has been limited research focused on understanding and synthesizing the factors that have been identified as contributing to victimization and substance abuse and on interventions designed to address these contributing factors. The purposes of this article are to (a) review the literature on factors related to victimization and substance abuse, (b) review interventions and outcomes, and (c) discuss clinical implications for interventions and research. Results suggest that there is a high rate of co-occurrence of victimization and substance abuse among women, that the factors contributing to victimization and substance abuse are complex, and that there is a lack of treatment models addressing victimization and substance abuse.

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