scholarly journals Illustrating a free, open-source method for quantifying locomotor performance with sprinting Aegean wall lizards

2014 ◽  
Author(s):  
Colin Donihue ◽  
Ben Kazez
Keyword(s):  
Natural History ◽  
Open Source ◽  
High Speed ◽  
Video Data ◽  
Locomotor Performance ◽  
Analysis Program ◽  
Video Cameras ◽  
High Speed Video ◽  
Position Data ◽  
Free Open Source

Locomotion is an important characteristic of many animals’ natural history. With the increasing availability of high-speed video cameras, videography is a powerful tool for analyzing fast or subtle motions with unprecedented resolution. However, the programs currently available for analyzing these videos are either dauntingly time intensive or prohibitively expensive. We have developed a free, open-source video analysis program, SAVRA, that enables the quick capture of scaled position data. Here we demonstrate its use with an analysis of several videos of the Aegean wall lizard (Podarcis erhardii). We hope making this program freely available will facilitate the analysis of video data across taxa, not just in laboratory settings but also in natural contexts.

scholarly journals Illustrating a free, open-source method for quantifying locomotor performance with sprinting Aegean wall lizards

2014 ◽  
Author(s):  
Colin Donihue ◽  
Ben Kazez
Keyword(s):  
Natural History ◽  
Open Source ◽  
High Speed ◽  
Video Data ◽  
Locomotor Performance ◽  
Analysis Program ◽  
Video Cameras ◽  
High Speed Video ◽  
Position Data ◽  
Free Open Source

Locomotion is an important characteristic of many animals’ natural history. With the increasing availability of high-speed video cameras, videography is a powerful tool for analyzing fast or subtle motions with unprecedented resolution. However, the programs currently available for analyzing these videos are either dauntingly time intensive or prohibitively expensive. We have developed a free, open-source video analysis program, SAVRA, that enables the quick capture of scaled position data. Here we demonstrate its use with an analysis of several videos of the Aegean wall lizard (Podarcis erhardii). We hope making this program freely available will facilitate the analysis of video data across taxa, not just in laboratory settings but also in natural contexts.

Identification of Release Conditions and Aerodynamic Forces in Pitched-Baseball Trajectories

2001 ◽  
Vol 17 (1) ◽  
pp. 63-76 ◽  
Author(s):  
LeRoy W. Alaways ◽  
Sean P. Mish ◽  
Mont Hubbard
Keyword(s):  
Drag Coefficient ◽  
Initial Velocity ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Three Dimensions ◽  
Video Cameras ◽  
High Speed Video ◽  
Position Data ◽  
Estimation Scheme ◽  
The Mean

Pitched-baseball trajectories were measured in three dimensions during competitions at the 1996 Summer Olympic games using two high-speed video cameras and standard DLT techniques. A dynamic model of baseball flight including aerodynamic drag and Magnus lift forces was used to simulate trajectories. This simulation together with the measured trajectory position data constituted the components of an estimation scheme to determine 8 of the 9 release conditions (3 components each of velocity, position, and angular velocity) as well as the mean drag coefficient CD and terminal conditions at home plate. The average pitch loses 5% of its initial velocity during flight. The dependence of estimated drag coefficient on Reynolds number hints at the possibility of the drag crisis occurring in pitched baseballs. Such data may be used to quantify a pitcher’s performance (including fastball speed and amount of curve-ball break) and its improvement or degradation over time. It may also be used to understand the effects of release parameters on baseball trajectories.

APPLICATION OF THE EARLY DAMAGE DIAGNOSTICS TECHNIQUE TO EXAMINATION OF THE AVIATION PANEL

2019 ◽  
Vol 85 (6) ◽  
pp. 53-63 ◽  
Author(s):  
I. E. Vasil’ev ◽  
Yu. G. Matvienko ◽  
A. V. Pankov ◽  
A. G. Kalinin
Keyword(s):  
Acoustic Emission ◽  
Damage Detection ◽  
High Speed ◽  
Early Stage ◽  
Video Data ◽  
High Speed Video ◽  
Damage Diagnostics ◽  
Subsurface Defect ◽  
Sensitive Coating ◽  
Early Damage

The results of using early damage diagnostics technique (developed in the Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAN) for detecting the latent damage of an aviation panel made of composite material upon bench tensile tests are presented. We have assessed the capabilities of the developed technique and software regarding damage detection at the early stage of panel loading in conditions of elastic strain of the material using brittle strain-sensitive coating and simultaneous crack detection in the coating with a high-speed video camera “Video-print” and acoustic emission system “A-Line 32D.” When revealing a subsurface defect (a notch of the middle stringer) of the aviation panel, the general concept of damage detection at the early stage of loading in conditions of elastic behavior of the material was also tested in the course of the experiment, as well as the software specially developed for cluster analysis and classification of detected location pulses along with the equipment and software for simultaneous recording of video data flows and arrays of acoustic emission (AE) data. Synchronous recording of video images and AE pulses ensured precise control of the cracking process in the brittle strain-sensitive coating (tensocoating)at all stages of the experiment, whereas the use of structural-phenomenological approach kept track of the main trends in damage accumulation at different structural levels and identify the sources of their origin when classifying recorded AE data arrays. The combined use of oxide tensocoatings and high-speed video recording synchronized with the AE control system, provide the possibility of definite determination of the subsurface defect, reveal the maximum principal strains in the area of crack formation, quantify them and identify the main sources of AE signals upon monitoring the state of the aviation panel under loading P = 90 kN, which is about 12% of the critical load.

scholarly journals Standard of the Initial Ball Velocity for a Fly Ball in Baseball Hitting

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 137
Author(s):  
Hirotaka Nakashima ◽  
Gen Horiuchi ◽  
Shinji Sakurai
Keyword(s):  
Initial Velocity ◽  
High Speed ◽  
Baseball Players ◽  
Ball Impact ◽  
Video Cameras ◽  
High Speed Video ◽  
Before And After ◽  
Ball Velocity ◽  
Opposite Field ◽  
Measuring Tape

This study aimed to determine the minimum required initial velocity to hit a fly ball toward the same field (left-field for right-handed batters), center field, and opposite field (right field for right-handed batters). Six baseball players hit fastballs launched by a pitching machine. The movements of the balls before and after bat-to-ball impact were recorded using two high-speed video cameras. The flight distance was determined using a measuring tape. Seventy-nine trials were analyzed, and the minimum required initial velocities of batted balls were quantified to hit balls 60, 70, 80, 90, 100, 110, and 120 m in each direction through regression analysis. As a result, to hit a ball 120 m, initial velocities of 43.0, 43.9, and 46.0 m/s were required for the same field, center field, and opposite field, respectively. The result provides a useful index for batters to hit a fly ball in each of the directions.

scholarly journals Modeling stepped leaders using a time-dependent multidipole model and high-speed video data

2015 ◽  
Vol 120 (6) ◽  
pp. 2419-2436 ◽  
Author(s):  
Sumedhe Karunarathne ◽  
Thomas C. Marshall ◽  
Maribeth Stolzenburg ◽  
Nadeeka Karunarathna ◽  
Richard E Orville
Keyword(s):  
High Speed ◽  
Video Data ◽  
Time Dependent ◽  
High Speed Video

scholarly journals Experimental analysis of high velocity impacts of composite fragments on aluminium plates

2021 ◽  
Vol 250 ◽  
pp. 01011
Author(s):  
Jorge López-Puente ◽  
Jesús Pernas-Sánchez ◽  
José Alfonso Artero-Guerrero ◽  
David Varas ◽  
Joseba Múgica ◽  
...  
Keyword(s):  
High Velocity ◽  
High Speed ◽  
Woven Composites ◽  
Residual Velocity ◽  
Video Cameras ◽  
High Speed Video ◽  
High Velocity Impacts ◽  
Deformable Structure ◽  
The Impact ◽  
Composite Blades

The improvement of engines is one of the ways to diminish the fuel consumption in civil aircrafts, and Open Rotors engines are one of the best promises in order to achieve a sensible efficiency increment. These engines have large composite blades that could, in the event of failure, impact against the fuselage, totally or partially. In this case, composite fragments could behave as impactors. In order to design fuselages for this event and adopt these new engines in the future, it is necessary to understand the impact behaviour of a composite fragment against a deformable structure. To this end, unidirectional and woven composites fragments were impacted at high velocity (up to 150 m/s) against aluminium panels at different impact velocities. The composite fragments were made using AS4/8552 (UD) and AGP-193PW (woven) prepregs manufactured by Hexcel Composites, both using AS4 fibres and 8552 epoxy matrix. High speed video cameras were used to record the impact process and to measure both the impact and the residual velocity and hence the energy absorbed.

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