Vibration analysis of acoustic guitar string employing high-speed video cameras

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.

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

EPJ Web of Conferences ◽

10.1051/epjconf/202125001011 ◽

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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Efficient subtle motion detection from high-speed video for sound recovery and vibration analysis using singular value decomposition-based approach

Optical Engineering ◽

10.1117/1.oe.56.9.094105 ◽

2017 ◽

Vol 56 (09) ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

Dashan Zhang ◽

Jie Guo ◽

Yi Jin

Keyword(s):

Singular Value Decomposition ◽

Motion Detection ◽

Vibration Analysis ◽

High Speed ◽

Singular Value ◽

High Speed Video ◽

Value Decomposition

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J027022 Kinematic analysis of dolphin jumping by using high-speed video cameras

The Proceedings of Mechanical Engineering Congress Japan ◽

10.1299/jsmemecj.2013._j027022-1 ◽

2013 ◽

Vol 2013 (0) ◽

pp. _J027022-1-_J027022-5

Author(s):

Yusuke UCHIDA ◽

Gen LI ◽

Masashi NAKAMURA ◽

Hiroto TANAKA ◽

Hao LIU

Keyword(s):

Kinematic Analysis ◽

High Speed ◽

Video Cameras ◽

High Speed Video

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Design and Development of a Robotic Bee for the Analysis of Honeybee Dance Communication

Applied Bionics and Biomechanics ◽

10.1155/2008/871297 ◽

2008 ◽

Vol 5 (3) ◽

pp. 157-164 ◽

Cited By ~ 4

Author(s):

T. Landgraf ◽

H. Moballegh ◽

R. Rojas

Keyword(s):

Visual Feedback ◽

High Speed ◽

Tracking System ◽

Feedback System ◽

High Speed Camera ◽

Video Cameras ◽

High Speed Video ◽

Successive Addition ◽

Essential Properties ◽

Dance Communication

We have designed a robotic honeybee to mimic the bee dance communication system. To achieve this goal, a tracking system has been developed to extract real bee dance trajectories recorded with high-speed video cameras. The results have been analysed to find the essential properties required for the prototype robot. Putative signals in the dance communication have been identified from the literature. Several prototypes were built with successive addition of more features or improvement of existing components. Prototypes were tested in a populated beehive results were documented using high-speed camera recordings. A substantial innovation is a visual feedback system that helps the robot to minimise collisions with other bees.

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Development of high-speed video cameras for Dynamic PIV

Journal of Visualization ◽

10.1007/bf03182329 ◽

2002 ◽

Vol 5 (3) ◽

pp. 213-224 ◽

Cited By ~ 3

Author(s):

G. T. Etoh ◽

K. Takehara ◽

Y. Takano

Keyword(s):

High Speed ◽

Video Cameras ◽

High Speed Video ◽

Dynamic Piv

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Mechanics and aerodynamics of perching manoeuvres in a large bird of prey

The Aeronautical Journal ◽

10.1017/s0001924000004152 ◽

2010 ◽

Vol 114 (1161) ◽

pp. 673-680 ◽

Cited By ~ 14

Author(s):

A. C. Carruthers ◽

A. L. R. Thomas ◽

S. M. Walker ◽

G. K. Taylor

Keyword(s):

High Speed ◽

High Lift ◽

Still Images ◽

Video Cameras ◽

Bird Of Prey ◽

High Speed Video ◽

Wing Profile ◽

Large Bird ◽

Flight Muscles

Abstract This paper reviews recent results on the mechanics and aerodynamics of perching in a large bird of prey, the Steppe Eagle Aquila nipalensis. Data collected using onboard and high-speed video cameras are used to examine gross morphing of the wing planform by the flight muscles, and smaller-scale morphing of the wing profile by aeroelastic deflection of the feathers, Carruthers et al. High-resolution still images are used to reconstruct the shape of the wing using multi-station photogrammetry, and the performance of the measured wing profile is analysed using a panel code, Carruthers et al. In bringing these lines of research together, we examine the role of aeroelastic feather deflection, and show that the key to perching in birds lies not in high-lift aerodynamics, but in the way in which the wings and tail morph to allow the bird to transition quickly from a steady glide into a deep stall.

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