Going mm-level recognition capability of BOTDA based on a transient pump pulse and an algorithm enhancement

2021 ◽  
Author(s):  
Dengwang Zhou ◽  
Dexin Ba ◽  
Benzhang Wang ◽  
Liqiang Qiu ◽  
Siwuliji Ha ◽  
...  
Keyword(s):  
Pump Pulse ◽  
Recognition Capability

scholarly journals Supercontinuum generation in photonic crystal fibers infiltrated with tetrachloroethylene

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Hieu Van Le ◽  
Van Thuy Hoang ◽  
Hue Thi Nguyen ◽  
Van Cao Long ◽  
Ryszard Buczynski ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Lattice Constant ◽  
Wavelength Range ◽  
Pump Pulse ◽  
Filling Factor ◽  
Photonic Crystal Fibers ◽  
Fused Silica ◽  
Anomalous Dispersion ◽  
Central Wavelength ◽  
Crystal Fibers

AbstractThis study proposes a photonic crystal fiber made of fused silica glass, with the core infiltrated with tetrachloroethylene (C2Cl4) as a new source of supercontinuum (SC) spectrum. We studied numerically the guiding properties of the several different fiber structures in terms of characteristic dispersion, mode area, and attenuation of the fundamental mode. Based on the results, the structural geometries of three C2Cl4-core photonic crystal fibers were optimized in order to support the broadband SC generations. The first fiber structure with lattice constant 1.5 μm and filling factor 0.4 operates in all-normal dispersion. The SC with a broadened spectral bandwidth of 0.8–2 μm is generated by a pump pulse with a central wavelength of 1.56 μm, 90 fs duration and energy of 1.5 nJ. The second proposed structure, with lattice constant 4.0 μm and filling factor 0.45, performs an anomalous dispersion for wavelengths longer than 1.55 μm. With the same pump pulse as the first fiber, we obtained the coherence SC spectrum in an anomalous dispersion range with wavelength range from 1 to 2 μm. Meanwhile, the third selected fiber (lattice constant 1.5 μm, filling factor 0.55) has two zero dispersion wavelengths at 1.04 μm and 1.82 μm. The octave-spanning of the SC spectrum formed in this fiber was achieved in the wavelength range of 0.7–2.4 μm with an input pulse whose optical properties are 1.03 μm wavelength, 120 fs duration and energy of 2 nJ. Those fibers would be good candidates for all-fiber SC sources as cost-effective alternatives to glass core fibers.

Emerging sensitivity to standards in toddlers: a necessary but insufficient condition for visual self-recognition in the rouge-task procedure?

2012 ◽  
pp. 167-182
Author(s):  
Paola Molina ◽  
Daniela Bulgarelli ◽  
Andre Vyt
Keyword(s):  
Decisive Role ◽  
The Self ◽  
Successful Performance ◽  
Self Recognition ◽  
Recognition Capability

Different explanations are put forward for the late acquisition of the(or rouge task) in comparison to other mirror tasks. A particularly interesting hypothesis about factors that mask success in MSR task concerns the growth of the appreciation of standards of proper behaviour, noticing deviations from normality in objects and in their own action (Mitchell, 1993, 1994). Standard sensitivity is proposed as a core factor in determining the self recognition capability. To test this hypothesis, we observed 40 infants, aged between 15 and 24 months, confronted with a spot on a doll's face, on the infant's hand, on the observer's face, and on the infant's face. Our data suggest that sensitivity to standards can be seen as a necessary but not sufficient requirement for success in thetask: other capacities, namely the development of representation, may play a decisive role in the successful performance on thetask.

scholarly journals Octave Spanning Supercontinuum in an As2S3 Taper using Ultra-low Pump Pulse Energy

2011 ◽  
Author(s):  
Darren D. Hudson ◽  
Stephen A. Dekker ◽  
Eric C. Magi ◽  
Alexander C. Judge ◽  
Stuart D. Jackson ◽  
...  
Keyword(s):  
Pump Pulse ◽  
Pulse Energy ◽  
Pump Pulse Energy

scholarly journals Effects of pump pulse energy and repetition rate on beam quality in a high-power mid-infrared ZnGeP2 OPO

2020 ◽  
Author(s):  
Marcin Piotrowski ◽  
Manuel Medina ◽  
Martin Schellhorn ◽  
Gerhard Spindler ◽  
Anne DHOLLANDE
Keyword(s):  
Pump Pulse ◽  
High Power ◽  
Pulse Energy ◽  
Repetition Rate ◽  
Beam Quality ◽  
Mid Infrared ◽  
Pump Pulse Energy

Assistive Technology based Solution for Hearing Impairment using Smartphone

2022 ◽  
Vol 10 (1) ◽  
pp. 0-0
Keyword(s):  
Gesture Recognition ◽  
Video Sequence ◽  
Recognition System ◽  
Language Recognition ◽  
Sign Language Recognition ◽  
Background Elimination ◽  
Sign Recognition ◽  
Limited Support ◽  
Recognition Capability ◽  
Better Than

Developing a system for sign language recognition becomes essential for the deaf as well as a mute person. The recognition system acts as a translator between a disabled and an able person. This eliminates the hindrances in the exchange of ideas. Most of the existing systems are very poorly designed with limited support for the needs of their day to day facilities. The proposed system embedded with gesture recognition capability has been introduced here which extracts signs from a video sequence and displays them on screen. On the other hand, a speech to text as well as text to speech system is also introduced to further facilitate the grieved people. To get the best out of a human-computer relationship, the proposed solution consists of various cutting-edge technologies and Machine Learning based sign recognition models that have been trained by using TensorFlow and Keras library. The proposed architecture works better than several gesture recognition techniques like background elimination and conversion to HSV

The Influence of Wave-Front-Distorted Pump Pulse on the Beam Quality of OPA Front-End System of the Petawatt Laser

2009 ◽  
Vol 29 (11) ◽  
pp. 3088-3093 ◽  
Author(s):  
王艳海 Wang Yanhai ◽  
潘雪 Pan Xue ◽  
李学春 Li Xuechun ◽  
林尊琪 Lin Zunqi
Keyword(s):  
Wave Front ◽  
Pump Pulse ◽  
Beam Quality ◽  
Front End
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