A transducer using PVDF film, which is placed on the eyelid, has been designed to measure intracranial blood flow noise, called “bruit”, as a screening test for detecting intracranial vascular deformations such as aneurysms, stenosis, and malformations. First, the mechanical impedance of the eye was measured. Then, the transducer performance on the eye was evaluated in terms of sensitivity versus frequency while varying the parameters of the transducer components. The prototype transducer fabricated had a sensitivity of −76dB(0dB=1V/(dyn/cm2)) at frequencies of up to around 1, 000Hz. It was successfully used in a neurosurgical clinic to measure the bruit signals, and was proved to be effective for detecting cerebral aneurysms and stenosis.
In order to realize musical performances with human-like emotions by computer, it is necessary to analyze performances using musical score data. The Dynamic Programming (DP) method is often used for matching between a musical score and its performance. However, the DP does not achieve a high matching rate since the ordering of attack of the notes in a chord is not always the same and there are difficult passages of right and left hand performances. Furthermore the score does not define the number of iterations of trills. This paper addresses the process of matching two or more MIDI performance data involving DP along with linear interpolation to maximize the collation between the score and the performance. The improved DP method is also extended to match performances including trills.
This paper deals with three-dimensional (3D) image reconstruction algorithm based on two-dimensional (2D) subaperture processing. For real-time volumetric imaging, high frame rate and high beam density are required. Herein, we suggest a new subaperture processing technique where the small number of array elements is fired at the array centre and the returned echo signals are acquired from the consecutive receiving subapertures. The number of beam lines to scan a sector image was chosen according to the Nyquist sampling criterion of a single transmit-receive subaperture. The beam number is increased to the required synthesized array by digital interpolation.
In order to investigate the possibility of Oriental lacquer (urushi) as a coating for the wooden-soundboard of musical instruments, the effects of urushi coatings on the vibrational properties of wood were compared to those of conventional coatings. By coating, the dynamic Young’s modulus of wood decreased slightly in its fiber direction whereas that in the radial direction increased. The most remarkable changes due to coating were recognized in the internal friction of wood (Q-1), especially that in the radial direction. The effect of the urushi coating on the Q-1 of wood was relatively small and very close to those of polyurethane coating used for the soundboard of harp. The viscoelastic and mechanical properties of urushi lacquer films were also similar to those of the polyurethane lacquer film. These results suggested the possibility of urushi as a coating for the harp soundboard. The effects of coatings on the vibrational properties of wood were explained by using a model considering three layers, the uncoated wood, coating layer, and a layer consisting of lacquer and wood cell wall.
We measured equal-loudness level contours for tone bursts lasting about 20ms. The results, which need to be confirmed, suggest that equal-loudness contours for tone bursts are similar to those in ISO226 for long-duration tones at frequencies below 6kHz but not at higher frequencies.