Visual Tracking of Box Jellyfish

2015 ◽  
pp. 107-122 ◽  
Author(s):  
Magnus Oskarsson ◽  
Tobias Kjellberg ◽  
Tobias Palmér ◽  
Dan-Eric Nilsson ◽  
Kalle Åström
Keyword(s):  
High Speed ◽  
Motor Response ◽  
Building Blocks ◽  
Video Sequences ◽  
Special Test ◽  
Real Time System ◽  
Test Setup ◽  
Box Jellyfish ◽  
High Speed Video ◽  
Sensory Structures

In this chapter a system for tracking the motion of box jellyfish Tripedalia cystophora in a special test setup is investigated. The goal is to measure the motor response of the animal given certain visual stimuli. The approach is based on tracking the special sensory structures - the rhopalia - of the box jellyfish from high-speed video sequences. The focus has been on a real-time system with simple building blocks in the system. However, using a combination of simple intensity based detection and model based tracking promising tracking results with up to 95% accuracy are achieved.

scholarly journals Influence of liquid properties on ultrasonic atomization

2017 ◽  
Author(s):  
Antonio Lozano ◽  
Juan Antonio García ◽  
Javier Alconchel ◽  
Félix Barreras ◽  
Esteban Calvo ◽  
...  
Keyword(s):  
Surface Tension ◽  
Weight Loss ◽  
Vapor Pressure ◽  
High Speed ◽  
Liquid Surface ◽  
Video Sequences ◽  
Narrow Size Distribution ◽  
Piezoceramic Disk ◽  
Ultrasonic Atomization ◽  
High Speed Video

Ultrasonic atomization is very convenient because it can generate droplets with diameters of a few microns andwith very narrow size distribution. Besides, opposite to twin fluid nozzles, in ultrasonic atomization, dropletgeneration and transport are decoupled processes. Droplets are ejected from the liquid surface with very lowvelocities, so driving them is relatively simple. Although this atomization method is now common in some specificapplications, for example in household humidifiers, there are still some details about the physics of this processthat are not completely understood. Up to date, most of the published results have been limited to experimentswith water. However, it has been demonstrated that atomization rates quickly decrease as liquid viscosityincreases. This work analyzes the characteristics of ultrasonic atomization of some alternative fluids to determineif there is any influence of other physical properties such as surface tension or vapor pressure. Experiments areperformed using a commercial piezoceramic disk with a resonance frequency of 1.65 MHz. The disk is excitedwith a sinusoidal signal with voltage amplitudes that go up to 60 V. Sprays are visually characterized analyzinginstantaneous images and high speed video sequences. Besides atomization rates are calculated by measuringthe weight loss in a fixed time.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4588

scholarly journals Perforation of Double-Spaced Aluminum Plates by Reactive Projectiles with Different Densities

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1229
Author(s):  
Hao Zhang ◽  
Haifu Wang ◽  
Qingbo Yu ◽  
Yuanfeng Zheng ◽  
Guancheng Lu ◽  
...  
Keyword(s):  
Theoretical Prediction ◽  
Initial Velocity ◽  
High Speed ◽  
Spray Angle ◽  
Video Sequences ◽  
Material Density ◽  
High Speed Video ◽  
Front Plate ◽  
Critical Velocities ◽  
Aluminum Plates

Perforation behavior of 3 mm/3 mm double-spaced aluminum plates by PTFE/Al/W (Polytetrafluoroethylene/Aluminum/Tungsten) reactive projectiles with densities ranging from 2.27 to 7.80 g/cm3 was studied experimentally and theoretically. Ballistic experiments show that the failure mode of the front plate transforms from petalling failure to plugging failure as projectile density increases. Theoretical prediction of the critical velocities for the reactive projectiles perforating the double-spaced plates is proposed, which is consistent with the experimental results and well represents the perforation performance of the projectiles. Dimensionless formulae for estimating the perforation diameter and deflection height of the front plates are obtained through dimensional analysis, indicating material density and strength are dominant factors to determine the perforation size. High-speed video sequences of the perforation process demonstrate that high-density reactive projectiles make greater damage to the rear plates because of the generation of projectile debris streams. Specifically, the maximum spray angle of the debris streams and the crater number in the debris concentration area of the rear plate both increase with the projectile density and initial velocity.

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.

An all optical photonic crystal half adder suitable for optical processing applications

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamed Azhdari ◽  
Sahel Javahernia
Keyword(s):  
Photonic Crystal ◽  
Optical Waveguides ◽  
High Speed ◽  
Building Blocks ◽  
Optical Signal ◽  
Ring Resonators ◽  
Optical Processing ◽  
Nonlinear Photonic Crystal ◽  
Half Adder ◽  
All Optical

Abstract Increasing the speed of operation in all optical signal processing is very important. For reaching this goal one needs high speed optical devices. Optical half adders are one of the important building blocks required in optical processing. In this paper an optical half adder was proposed by combining nonlinear photonic crystal ring resonators with optical waveguides. Finite difference time domain method wase used for simulating the final structure. The simulation results confirmed that the rise time for the proposed structure is about 1 ps.

scholarly journals 2D-3D integration of hexagonal boron nitride and a high-κ dielectric for ultrafast graphene-based electro-absorption modulators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hitesh Agarwal ◽  
Bernat Terrés ◽  
Lorenzo Orsini ◽  
Alberto Montanaro ◽  
Vito Sorianello ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hafnium Oxide ◽  
High Speed ◽  
Hexagonal Boron Nitride ◽  
Temperature Stability ◽  
Cost Effective ◽  
Fold Increase ◽  
Building Blocks ◽  
High Quality ◽  
New Device

AbstractElectro-absorption (EA) waveguide-coupled modulators are essential building blocks for on-chip optical communications. Compared to state-of-the-art silicon (Si) devices, graphene-based EA modulators promise smaller footprints, larger temperature stability, cost-effective integration and high speeds. However, combining high speed and large modulation efficiencies in a single graphene-based device has remained elusive so far. In this work, we overcome this fundamental trade-off by demonstrating the 2D-3D dielectric integration in a high-quality encapsulated graphene device. We integrated hafnium oxide (HfO2) and two-dimensional hexagonal boron nitride (hBN) within the insulating section of a double-layer (DL) graphene EA modulator. This combination of materials allows for a high-quality modulator device with high performances: a ~39 GHz bandwidth (BW) with a three-fold increase in modulation efficiency compared to previously reported high-speed modulators. This 2D-3D dielectric integration paves the way to a plethora of electronic and opto-electronic devices with enhanced performance and stability, while expanding the freedom for new device designs.

scholarly journals WindFlow: High-Speed Continuous Stream Processing with Parallel Building Blocks

2021 ◽  
pp. 1-1
Author(s):  
Gabriele Mencagli ◽  
Massimo Torquati ◽  
Andrea Cardaci ◽  
Alessandra Fais ◽  
Luca Rinaldi ◽  
...  
Keyword(s):  
High Speed ◽  
Stream Processing ◽  
Building Blocks ◽  
Continuous Stream
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