Ferroelectric P(VDF-TrFE) as a large-scale piezoelectric sensor in a table-tennis racquet

2009 ◽  
Author(s):  
M. Wegener ◽  
T. Greco ◽  
K. Arlt ◽  
R. Schuberth ◽  
A. Morschhauser ◽  
...  
Keyword(s):  
Large Scale ◽  
Piezoelectric Sensor ◽  
Table Tennis

scholarly journals Defect Visualization of a Steel Structure Using a Piezoelectric Line Sensor Based on Laser Ultrasonic Guided Wave

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3992 ◽  
Author(s):  
Sang-Hyeon Kang ◽  
Dae-Hyun Han ◽  
Lae-Hyong Kang
Keyword(s):  
Large Scale ◽  
Steel Structure ◽  
Piezoelectric Sensor ◽  
Guided Wave ◽  
Laser Ultrasonic ◽  
Thermoelastic Wave ◽  
Multiple Sensors ◽  
Ultrasonic Guided Wave ◽  
Defect Area ◽  
Ultrasonic Propagation

We studied the detection and visualization of defects in a test object using a laser ultrasonic guided wave. The scan area is irradiated by a laser generated from a Nd:YAG 532 nm Q-switched laser generator through a galvanometer scanner. The laser irradiation causes the surface temperature to suddenly rise and then become temporarily adiabatic. The locally heated region reaches thermal equilibrium with the surroundings. In other words, heat energy propagates inside the object in the form of elastic energy through adiabatic expansion. This thermoelastic wave is typically acquired by a piezoelectric sensor, which is sensitive in the ultrasonic domain. A single piezoelectric sensor has limited coverage in the scan area, while multi-channel piezoelectric sensors require many sensors, large-scale wiring, and many channeling devices for use and installation. In addition, the sensors may not acquire signals due to their installed locations, and the efficiency may be reduced because of the overlap between the sensing areas of multiple sensors. For these reasons, the concept of a piezoelectric line sensor is adopted in this study for the first time. To verify the feasibility of the line sensor, I- and L-shaped sensors were attached to a steel structure, and the ultrasound signal from laser excitation was obtained. If the steel structure has defects on the back, the ultrasonic propagation image will be distorted in the defect area. Thus, we can detect the defects easily from the visualization image. Three defects were simulated for the test. The results show that the piezoelectric line sensor can detect defects more precisely and accurately compared to a single piezoelectric sensor.

Rich lamellar crystal baklava-structured PZT/PVDF piezoelectric sensor toward individual table tennis training

Nano Energy ◽  
2019 ◽  
Vol 59 ◽  
pp. 574-581 ◽  
Author(s):  
Guo Tian ◽  
Weili Deng ◽  
Yuyu Gao ◽  
Da Xiong ◽  
Cheng Yan ◽  
...  
Keyword(s):  
Piezoelectric Sensor ◽  
Table Tennis ◽  
Lamellar Crystal

scholarly journals Enhancing Fan Engagement in a 5G Stadium with AI-Based Technologies and Live Streaming

2021 ◽  
Author(s):  
Cheng-Wen Wu ◽  
Ming-Der Shieh ◽  
Jenn-Jier Lien ◽  
Jar- Ferr Yang ◽  
Wei-Ta Chu ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Video Stream ◽  
Live Streaming ◽  
Wide Field ◽  
Tennis Ball ◽  
Table Tennis ◽  
Sports Industry ◽  
Broadcasting System ◽  
Sport Events

<div>Abstract—It has been tough for the sports industry and the athletes during the COVID-19 pandemic, but in Taiwan, we have been lucky to contain the pandemic to a level that we could hold the 2021 National Intercollegiate Athletic Games (NIAG) in early May. We formed a Sport Technology Team of more than 30 scholars, students, and engineers to provide novel systems and solutions that make the athletic games rich of sport technologies. Some of the features could be the first time shown to the internet audience for large-scale athletic games. The technologies involved include table tennis ball trajectory and bounce distribution, badminton shuttlecock tracking and trajectory, augmented reality enriched content for real-time video streaming on social networks, real-time 3D broadcasting with wide-field free viewangle, in-stadium video stream pushing by private 5G network with Mobile Edge Computing (MEC), AI-based sport data analytics during live streaming, a Technology-Enhanced Broadcasting System for sport events, etc. This paper introduces the respective technologies that we have developed, deployed, and demonstrated in the 2021 NIAG, Taiwan. We stress the architecture design and integration of TBS, which is a System of Systems, as well as experimental results on real athletic games in the smart stadiums that we have established.</div>

Life-cycle health monitoring of composite structures using piezoelectric sensor network

2021 ◽  
Author(s):  
yinghong yu ◽  
Xiao Liu ◽  
jun li ◽  
Yishou Wang ◽  
xinlin qing
Keyword(s):  
Life Cycle ◽  
Sensor Network ◽  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Composite Structures ◽  
Large Scale ◽  
Structural Integrity ◽  
Piezoelectric Sensor ◽  
Curing Process ◽  
Whole Life Cycle

Abstract The vacuum-assisted resin infusion (VARI) technique provides considerable advantages in manufacturing large-scale composite structures. An accurate and consecutive structural health monitoring system is urgently required to determine the initial quality and assess the structural integrity of a composite structure. In this paper, a real-time active smart diagnostic system (SDS) based on piezoelectric sensor network is proposed to monitor the whole life-cycle of composite structures. Experiments were conducted on carbon fiber reinforced plastic (CFRP) specimens with different thicknesses to investigate the monitoring capability of piezoelectric lead-zirconate-titanate (PZT) sensors used in the SDS approach. The PZT sensor networks inserted inside the composite structures during the VARI process are used to monitor not only the curing parameters, but also the health status of composite structures when they are in service after curing. To monitor the curing process only, the sensor network can also be installed on the bottom of the mould. Experimental results demonstrate that both three-dimensional resin flow and degree of cure (DOC) in the VARI process can be effectively monitored by the PZT sensor network. Meanwhile, the embedded PZT sensor network has the potential to identify the different stages in the curing process. It is obvious that the piezoelectric sensor network will provide important technical support for composite materials with the structure and function integrated.

scholarly journals Enhancing Fan Engagement in a 5G Stadium with AI-Based Technologies and Live Streaming

2021 ◽  
Author(s):  
Cheng-Wen Wu ◽  
Ming-Der Shieh ◽  
Jenn-Jier Lien ◽  
Jar- Ferr Yang ◽  
Wei-Ta Chu ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Video Stream ◽  
Live Streaming ◽  
Wide Field ◽  
Tennis Ball ◽  
Table Tennis ◽  
Sports Industry ◽  
Broadcasting System ◽  
Sport Events

<div>Abstract—It has been tough for the sports industry and the athletes during the COVID-19 pandemic, but in Taiwan, we have been lucky to contain the pandemic to a level that we could hold the 2021 National Intercollegiate Athletic Games (NIAG) in early May. We formed a Sport Technology Team of more than 30 scholars, students, and engineers to provide novel systems and solutions that make the athletic games rich of sport technologies. Some of the features could be the first time shown to the internet audience for large-scale athletic games. The technologies involved include table tennis ball trajectory and bounce distribution, badminton shuttlecock tracking and trajectory, augmented reality enriched content for real-time video streaming on social networks, real-time 3D broadcasting with wide-field free viewangle, in-stadium video stream pushing by private 5G network with Mobile Edge Computing (MEC), AI-based sport data analytics during live streaming, a Technology-Enhanced Broadcasting System for sport events, etc. This paper introduces the respective technologies that we have developed, deployed, and demonstrated in the 2021 NIAG, Taiwan. We stress the architecture design and integration of TBS, which is a System of Systems, as well as experimental results on real athletic games in the smart stadiums that we have established.</div>

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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