Although a small point ultrasound transducer has a wide acceptance angle, its small active area leads to a high thermal-noise-induced electric voltage in the transducer, thus the sensitivity is low. By contrast, a finite-size flat transducer has high sensitivity, but the acceptance angle is small, which limits its application in reconstruction-based photoacoustic tomography (PAT). Here, we prop...

[57] ABSTRACT A ?exible system for determining the quality of agricul tural products based on characteristics such as, for ex ample, mass, shape, hardness, size, color and surface texture is disclosed herein. The quality determination apparatus includes a feeder assembly for sequentially dropping individual product samples upon an impact transducer arrangement. The impact transducer gener ates ...

Objective of this study was to investigate the influence of the transducer positioning angle deviation from its supposed position on the 3D reflections from a triangle reflector. For that an acoustic computer model using the Huygens approach, which enables calculation of the signals reflected by the triangles in 3D space was used. Modelling was performed at different deflection angles of triang...

Hall effect sensors have been used for some time in application where presence detection over short distances is required, as a replacement for mechanical transducers. This has yielded improvements in reliability and manufacturing cost. The integration of the Hall transducer along with the signal conditioning circuit has improved overall performance and at the same time reduced the application ...

We introduce a weighted tree transducer model that combines aspects of weighted top down tree transducers and monadic datalog; this allows us to specify information transport for non-adjacent nodes in a single rule. We will investigate four different semantics for our weighted tree transducer model and prove that they coincide under certain conditions. We present and prove the correctness of an...

An ultrasonic transducer is a key component to achieve ultrasonic imaging. This paper designs a new type of Microelectromechanical Systems (MEMS) based capacitive ultrasonic transducer and a linear array based on the transducer. Through directivity analysis, it can be found that its directivity is weak due to the small size of the designed transducer, but the directivity of the designed linear ...

When applying feedback control in active noise control, phase lag caused by transducer dynamics and time delay between microphones and noise sources limits the bandwidth of the controller considerably. The proposed method to increase stability is to compensate the phase lag by applying a Smith compensator. The compensator needs a model of the acoustic plant. As model, only the transducer dynami...