New Approach to Assess in Vivo Rearfoot Control of Court Footwear during Side-Stepping Moves

1997 ◽  
Vol 13 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Mario A. Lafortune
Keyword(s):  
High Speed ◽  
Pressure Sensors ◽  
Experimental Results ◽  
Lateral Side ◽  
New Approach ◽  
High Speed Video ◽  
High Discrimination

Miniature pressure sensors and high-speed video were used to assess the lateral support and stability of court footwear during in vivo performance of lateral side-stepping moves. Two distinct types of court footwear construction were evaluated and were found to differ by approximately 100% and 200% in lateral support and stability, respectively. The heel control index that combined both parameters revealed differences exceeding 425%. A comparison of shoes that differed only in one construction feature produced similar trends. These overall results suggest that the combined high-speed video/pressure approach allows high discrimination of footwear rearfoot control properties during in vivo simulated playing conditions. The specific experimental results suggest that footwear designed for court sports exhibits considerable differences in foot support and stability. Furthermore, it was found that some construction features could improve these properties in court footwear.

Yaw Galloping of a TLWP Platform Under High Speed Currents by Analytical Methods and its Comparison With Experimental Results

2017 ◽  
Author(s):  
Francisco Lamas ◽  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes
Keyword(s):  
High Speed ◽  
Production Systems ◽  
Experimental Tests ◽  
Experimental Results ◽  
Analytical Methodology ◽  
New Approach ◽  
Laboratory Facilities ◽  
Polynomial Curve ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses

Flow Induced Motions are always an important subject during both design and operational phases of an offshore platform life. These motions could significantly affect the performance of the platform, including its mooring and oil production systems. These kind of analyses are performed using basically two different approaches: experimental tests with reduced models and, more recently, with Computational Fluid Dynamics (CFD) dynamic analysis. The main objective of this work is to present a new approach, based on an analytical methodology using static CFD analyses to estimate the response on yaw motions of a Tension Leg Wellhead Platform on one of the several types of motions that can be classified as flow-induced motions, known as galloping. The first step is to review the equations that govern the yaw motions of an ocean platform when subjected to currents from different angles of attack. The yaw moment coefficients will be obtained using CFD steady-state analysis, on which the yaw moments will be calculated for several angles of attack, placed around the central angle where the analysis is being carried out. Having the force coefficients plotted against the angle values, we can adjust a polynomial curve around each analysis point in order to evaluate the amplitude of the yaw motion using a limit cycle approach. Other properties of the system which are flow-dependent, such as damping and added mass, will also be estimated using CFD. The last part of this work consists in comparing the analytical results with experimental results obtained at the LOC/COPPE-UFRJ laboratory facilities.

Solidification Front Velocity of Ternary Titanium-Aluminides

1995 ◽  
Vol 398 ◽  
Author(s):  
M. Wettlaufer ◽  
J. Laakmann
Keyword(s):  
Experimental Data ◽  
Temperature Measurement ◽  
Solidification Front ◽  
High Speed ◽  
Titanium Aluminides ◽  
Front Velocity ◽  
Experimental Results ◽  
Video System ◽  
High Speed Video ◽  
Bulk Undercooling

ABSTRACTTernary titanium-aluminides with compositions of Ti51Al47Fe2, Ti51A147Cr2 and Ti51Al47Mn2 were investigated with respect to the correlation of their solidification front velocity v and bulk undercooling ΔT. The observation of the solidification front during the recalescence event has been realized using a high speed video system capable of recording up to 12,000 pictures per second. The temperature measurement was carried out by pyrometry, avoiding contact with the sample. The comparison of the experimental data with the LKT-theory (Lipton, Kurz, Trivedi; [1]) refers to a primary (hcp) β-Ti solidification for undercoolings below ΔT≈ 130 K and primary (bcc) α-Ti solidification for ΔT≥ 130 K. For undercoolings ≥ 150 K the theory differs greatly from the experimental results.The maximum undercoolings achieved were 268 K (Ti51Al47Fe2), 285 K (Ti51Al47Cr2) and 280 K (Ti51Al47Mn2), corresponding to a solidification front velocity v ≈ 9-10 m/s for all alloys.

New approach using flatness-based control in high speed positioning: Experimental results

2015 ◽  
Author(s):  
Daniel Beckmann ◽  
Moritz Schappler ◽  
Matthias Dagen ◽  
Tobias Ortmaier
Keyword(s):  
High Speed ◽  
Experimental Results ◽  
New Approach

scholarly journals Direct Measurement and Modeling of Intraglottal, Subglottal, and Vocal Fold Collision Pressures during Phonation in an Individual with a Hemilaryngectomy

2021 ◽  
Vol 11 (16) ◽  
pp. 7256
Author(s):  
Daryush D. Mehta ◽  
James B. Kobler ◽  
Steven M. Zeitels ◽  
Matías Zañartu ◽  
Emiro J. Ibarra ◽  
...  
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Pressure Sensors ◽  
Pressure Probe ◽  
Surgical Removal ◽  
In Vivo Measurement ◽  
Dual Sensor ◽  
The Right ◽  
Collision Pressure

The purpose of this paper is to report on the first in vivo application of a recently developed transoral, dual-sensor pressure probe that directly measures intraglottal, subglottal, and vocal fold collision pressures during phonation. Synchronous measurement of intraglottal and subglottal pressures was accomplished using two miniature pressure sensors mounted on the end of the probe and inserted transorally in a 78-year-old male who had previously undergone surgical removal of his right vocal fold for treatment of laryngeal cancer. The endoscopist used one hand to position the custom probe against the surgically medialized scar band that replaced the right vocal fold and used the other hand to position a transoral endoscope to record laryngeal high-speed videoendoscopy of the vibrating left vocal fold contacting the pressure probe. Visualization of the larynx during sustained phonation allowed the endoscopist to place the dual-sensor pressure probe such that the proximal sensor was positioned intraglottally and the distal sensor subglottally. The proximal pressure sensor was verified to be in the strike zone of vocal fold collision during phonation when the intraglottal pressure signal exhibited three characteristics: an impulsive peak at the start of the closed phase, a rounded peak during the open phase, and a minimum value around zero immediately preceding the impulsive peak of the subsequent phonatory cycle. Numerical voice production modeling was applied to validate model-based predictions of vocal fold collision pressure using kinematic vocal fold measures. The results successfully demonstrated feasibility of in vivo measurement of vocal fold collision pressure in an individual with a hemilaryngectomy, motivating ongoing data collection that is designed to aid in the development of vocal dose measures that incorporate vocal fold impact collision and stresses.

scholarly journals High-Speed Video Encoding System Based on H.264 and DSP

2012 ◽  
Vol 6-7 ◽  
pp. 416-421
Author(s):  
Chou Chen Wang ◽  
Zhi Hao Huang ◽  
Han Yen Chen ◽  
Jyun Liang Li
Keyword(s):  
Motion Estimation ◽  
High Speed ◽  
Video Encoding ◽  
Experimental Results ◽  
Similarity Matching ◽  
Data Movement ◽  
High Speed Video ◽  
Pattern Similarity ◽  
Speed Up ◽  
Partial Distortion

In this paper, a high-speed H.264 encoder based on ADI BF548 Blackfin DSP is proposed. In order to speed up the process of motion estimation (ME) module in H.264, we propose a two-step bit-transform-based normalized partial distortion search (TSB-NPDS) algorithm for fast ME by using the characteristics of pattern similarity matching errors. An initial standard compliant raw-C encoder has been optimized in speed for target processor. In addition, the parallelism between algorithm execution and data movement has been fully exploited using DMA. Experimental results demonstrate that the encoding rate can reach above 30 fps as using QCIF video.

scholarly journals Flagellar kinematics reveals the role of environment in shaping sperm motility

2020 ◽  
Vol 17 (170) ◽  
pp. 20200525
Author(s):  
Jeffrey S. Guasto ◽  
Jonathan B. Estrada ◽  
Filippo Menolascina ◽  
Lisa J. Burton ◽  
Mohak Patel ◽  
...  
Keyword(s):  
Sperm Motility ◽  
High Speed ◽  
Genetic Relatedness ◽  
Marine Invertebrates ◽  
Selective Pressure ◽  
Genetic Studies ◽  
New Approach ◽  
High Speed Video ◽  
Fluid Environment

Swimming spermatozoa from diverse organisms often have very similar morphologies, yet different motilities as a result of differences in the flagellar waveforms used for propulsion. The origin of these differences has remained largely unknown. Using high-speed video microscopy and mathematical analysis of flagellar shape dynamics, we quantitatively compare sperm flagellar waveforms from marine invertebrates to humans by means of a novel phylokinematic tree. This new approach revealed that genetically dissimilar sperm can exhibit strikingly similar flagellar waveforms and identifies two dominant flagellar waveforms among the deuterostomes studied here, corresponding to internal and external fertilizers. The phylokinematic tree shows marked discordance from the phylogenetic tree, indicating that physical properties of the fluid environment, more than genetic relatedness, act as an important selective pressure in shaping the evolution of sperm motility. More broadly, this work provides a physical axis to complement morphological and genetic studies to understand evolutionary relationships.

scholarly journals In slow motion: radula motion pattern and forces exerted to the substrate in the land snailCornu aspersum(Mollusca, Gastropoda) during feeding

2019 ◽  
Vol 6 (7) ◽  
pp. 190222 ◽  
Author(s):  
Wencke Krings ◽  
Taissa Faust ◽  
Alexander Kovalev ◽  
Marco Thomas Neiber ◽  
Matthias Glaubrecht ◽  
...  
Keyword(s):  
Contact Area ◽  
High Speed ◽  
Slow Motion ◽  
Land Snail ◽  
Anatomical Structure ◽  
Motion Pattern ◽  
Local Pressure ◽  
High Speed Video ◽  
Cornu Aspersum

The radula is the anatomical structure used for feeding in most species of Mollusca. Previous studies have revealed that radulae can be adapted to the food or the substrate the food lies on, but the real,in vivoforces exerted by this organ on substrates and the stresses that are transmitted by the teeth are unknown. Here, we relate physical properties of the radular teeth ofCornu aspersum(Müller. 1774Vermium terrestrium et fluviatilium, seu animalium infusoriorum, helminthicorum, et testaceorum, non marinorum, succincta historia. Volumen alterum. Heineck & Faber, Havniæ & Lipsiæ.), a large land snail, with experiments revealing their radula scratching force. The radula motion was recorded with high-speed video, and the contact area between tooth cusps and the substrate was calculated. Forces were measured in all directions; highest forces (106.91 mN) were exerted while scratching, second highest forces while pulling the radula upwards and pressing the food against its counter bearing, the jaw, because the main ingesta disaggregation takes place during those two processes. Nanoindentation revealed that the tooth hardness and elasticity in this species are comparable to wood. The teeth are softer than some of their ingesta, but since the small contact area of the tooth cusps (227 µm2) transmits high local pressure (4698.7 bar) on the ingesta surface, harder material can still be cut or pierced with abrasion. This method measuring the forces produced by the radula during feeding could be used in further experiments on gastropods for better understanding functions and adaptations of radulae to ingesta or substrate, and hence, gastropods speciation and evolution.

A systematic characterization of the factors influencing polymerization and dynamic behavior of n-butyl cyanoacrylate

2017 ◽  
Vol 10 (2) ◽  
pp. 150-155 ◽  
Author(s):  
Bill H Wang ◽  
Melfort Boulton ◽  
Donald H Lee ◽  
David M Pelz ◽  
Stephen P Lownie
Keyword(s):  
Video Analysis ◽  
High Speed ◽  
Contact Angles ◽  
Polymerization Rate ◽  
Aqueous Environment ◽  
Complication Rates ◽  
Polymerization Time ◽  
High Speed Video

IntroductionBrain arteriovenous malformations are abnormal connections between arteries and veins without an intervening capillary bed. Endovascular glue embolization with N-butyl cyanoacrylate (NBCA) is an accepted form of treatment. The reported complication rates vary widely from 2% to 15%, and timing of polymerization appears to play a major role. Additionally, the interaction between NBCA and vessel surface as well as the presence of biological catalysts are poorly understood.MethodsPolymerization time was measured for mixtures of Lipiodol/NBCA of 50/50, 70/30, and 60/40. The influence of pH, temperature, and the presence of biological catalysts on polymerization time was investigated. Contact angles were measured on polyvinyl alcohol cryogel (PVA-C), silicone, and endothelial surfaces in a submerged aqueous environment to assess physical surface interactions. High speed video analysis of glue injection through a microcatheter was performed to characterize simulated coaxial flow.ResultsNBCA polymerization rate increased with pH and temperature. A hydrophilic surface such as PVA-C was better than silicone at mimicking the physical properties of endothelium. Live endothelium provided a catalytic surface that at least doubled the rate of polymerization. Blood products further increased the polymerization rate in the following order (slowest to fastest): plasma, platelets, red blood cells (RBCs), and lysed RBCs. These factors could explain the discrepancy between in vitro and in vivo results reported in the current literature. High speed video analysis of NBCA injection showed dripping to jetting transition with significant wall effect which deviated from previous ideal assumptions.ConclusionsThe determinants of NBCA polymerization rate are multifactorial and dependent mainly on the presence of biological catalysts coupled with flow related wall interaction.

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.

Measuring the effect of high-speed video data on the audio-visual speech recognition accuracy

2019 ◽  
pp. 26-34
Author(s):  
D. V. Ivanko ◽  
D. A. Ryumin ◽  
A. A. Karpov ◽  
M. Zelezny
Keyword(s):  
Speech Recognition ◽  
High Speed ◽  
Recognition Accuracy ◽  
Video Data ◽  
Visual Speech ◽  
High Speed Video ◽  
Visual Speech Recognition
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