We proposed a new method to measure the frequency-dependent attenuation of bio cells using piezoelectric ultrasonic transducer. The polyvinylidene fluoride (PVDF) polymer was employed as piezoelectric material to take...
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We proposed a new method to measure the frequency-dependent attenuation of bio cells using piezoelectric ultrasonic transducer. The polyvinylidene fluoride (PVDF) polymer was employed as piezoelectric material to take an advantage of its low acoustic impedance (2.7 Mrayl) so that the transmission of acoustic power will be improved by impedance matching with that of liquid medium. The thickness of PVDF film is 110 ¿m and the resonance frequency of the 1 st thickness mode is 8.7 MHz. In order to characterize the fabricated ultrasonic transducer, a transducer and an acoustic wave reflector were positioned face to face. The output voltage for reflected transmitted ultrasonic wave was measured with impulse method and was transformed into the Round Trip Insertion Loss (RTIL) where the dominant frequency ranges from 5 MHz to 9 MHz.
This paper presents the design and mechatronics implementation of a human stress detection system (HSDS) using a biomechanics approach. A simple, compact and easy to use system is developed and built on a 2-layer PCB....
This paper presents the design and mechatronics implementation of a human stress detection system (HSDS) using a biomechanics approach. A simple, compact and easy to use system is developed and built on a 2-layer PCB. It consists of two transducers, an LCD display and a micro-controller chip along with their respective interfacing circuits. After characterizing the two transducers, an algorithm was developed based on the measurements to classify the human stress condition. A simple classification rule that was adopted revealed that the system can detect 78% of the stressed examinees. The overall system success rate in identifying one of three states (relaxed, half stressed and stressed) was 60%. One major application for HSDS could be in the automotive industry were the driver condition is constantly monitored, and if a stress state is detected, the driver can be notified to stop the car and relax.
In this paper the authors study the applicability of Artificial Neural Networks for the modelling of a widely used particular welding process in automotive industry: pulsed gas metal welding process (GMAW-P). Applying...
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In this paper the authors study the applicability of Artificial Neural Networks for the modelling of a widely used particular welding process in automotive industry: pulsed gas metal welding process (GMAW-P). Applying this artificial intelligence technology requires the introduction of input and output data to the network. To achieve this, an experiment was designed and performed. The main functions of the proposed model are: to simulate the process for purposes of training operators;to improve welding process performance by identifying regions that are insensible to variations on input parameters;and finally to increase the flexibility of a robotic welding cell. The concrete benefits obtained from the GMAW-P process model development are: optimization of critical variables of the welding process, support for development of virtual process and prototypes, definition of a robust welding procedure, quick response to product change and support in welding training.
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