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Page 883 of 977 Results 8821 - 8830 of 9762

Jan Holub, Michael Street, Ondrej Tomiska
COMPUTATIONALLY EFFICIENT NON-INTRUSIVE ALGORITHM FOR SPEECH TRANSMISSION QUALITY MEASURMENT

A new, wavelet-based, non-intrusive method for speech transmission quality measurements is described in the abstract. It models human perception of quality of transmitted speech signal. The deployed Discrete Wavelet Transform, in comparison with Fourier Transform, enables to reduce the computational power. In comparison with standardized methods (based on ITU-T P.563 algorithms), the described method saves about 90% of operations needed, achieving about 90% of the results of P.563. Thus, it is suitable for operational continuous assessment, or even for applications embedded in the mobile terminal.

Maura Casadio, Alessandro Noriaki Ide, Pietro G. Morasso, Vittorio Sanguineti
COMPUTER HAPTICS FOR NEUROMOTOR REHABILITATION

The paper proposes an approach for linking the analysis of the neural control of movement and motor learning with robot therapy in neuromotor rehabilitation. A new haptic workstation is described and a pilot study of robot therapy with hemiplegic patients is presented.

Anna Ostaszewska, Sabina śebrowska-Łucyk, Rafał Kłoda
METROLOGY PROPERTIES OF HUMAN OBSERVER IN COMPRESSED VIDEO QUALITY EVALUATION

The main purpose of this paper is to present the method of subjective quality evaluation recommended by International Telecommunication Union and the results obtained. Authors propose a bunch of factors describing an individual viewer.

Teresa Goodman, Alistair Forbes, Helen Walkey
A PRACTICAL MODEL FOR MESOPIC PHOTOMETRY

This article reports the results of a multinational research project investigating visual performance in halflight (mesopic) conditions. From the experimental investigations using reaction time, detection threshold and recognition contrast threshold techniques, the results were used to develop a system for practical mesopic photometry, which provides an acceptably good fit to the experimental data and is also suitable for practical implementation by the lighting industry. A major feature of the model is that it can be implemented in terms of photopic and scotopic luminance measurements, measurements that can easily be made in practice.

Koji Ito, Tsutomu Imai, Toshiyuki Kondo
MOTOR ADPTATION TO DYNAMIC ENVIRONMENTS IN ARM REACHING MOTIONS

In daily life, humans must compensate for the resultant forces arising form interaction with the physical environment. Recent studies have shown that humans can acquire a neural representation of the relation between motor command and movement, i.e. learn an internal model of the environment dynamics. The present paper discusses whether humans can identify one side of dynamics from the mixed environment dynamics in the case where humans have experienced either of them.

Milan Kvasnica
PROPERTIES OF SIX DOF MEASUREMENTS FOR ROBOTICS AND CONTROL

he paper is focused on the analyze of the accuracy and linearity of the six degrees-of-freedom (DoF) measurement system for the sampling of structural dynamic properties in robotics, engineering constructions and for control operation in space. The subject of this measurement device is the sampling and information processing used in the conversion of the 2-D CCD array images into three axial and three angular displacement values. Every 2- CCD array image consists of one, alternatively four light spot produced by light rays from four laser sources. These light beams form the edges of a pyramidal shape with one, alternatively four 2-D arrays forming its base and the intersection of laser light rays is forming its apex. The analyze of the accuracy and the linearity is based on algorithms for direct and inverse transformation for the computation of three axial shiftings and three angular displacements values in order to determine the relative location and orientation of a floating 2-D coordinate system against fixed 3-D coordinate system of laser rays.

Jerzy Sładek, Grzegorz Sokal
THE CORRECTION OF THE MEASURING ACCURACY OF THE INDUSTRIAL ROBOT BY USING ARTIFICIAL NEURAL NETWORKS

Using industrial robots to the measurement tasks in the field of multicoordinate metrology is worth the interest. But it demands performing adaptation process, correcting the measuring accuracy if needed and determining the field of measuring tasks. During the adaptation process it is important to perform analysis of the accuracy of built measurement system. In the case of lack of accuracy it is indispensable to correct this values. The use of software methods like ANN (Artifical Neural Networks) seems to be expedient, because it is not the mechanical interference. The point of the described method is the determination of error in the given spaces. Then it is possible to built the accuracy model of whole robots space.

Mariolino De Cecco, Luca Baglivo, Enrico Ervas, Enrico Marcuzzi
ASYNCHRONOUS AND TIME-DELAYED SENSOR FUSION OF A LASER SCANNER NAVIGATION SYSTEM AND ODOMETRY

This paper presents a description of the ‘sensor fusion’ algorithm for our proprietary new navigation system, the LS_NAV, which is based on laser range scanning data inside natural environment. The fusion is exploited between odometric navigation and the LS_NAV. In the proposed algorithm the accuracy of both navigation systems is estimated as a function of the actual manoeuvre being carried out. The method allows compensating the drift of the incremental system estimation, high data rate and noise reduction of the LS_NAV estimates. Experimental verification is carried out using an autonomous vehicle.

Jaromír Volf, Josef Vlček
INVESTIGATION FOR TIMBER BARKING ROBOTIZED SYSTEM PERFORMANCE

The original Timber Barking Principle – Using Electrical Current Effects has been tested for an industry timber barking purposes. This untraditional timber barking - no wood loss - method demands the special measuring Stand By Post to be done – for the parameters identification and setting; to be realized the voltage control for the Timber Barking Model with Operational Dimensions. The other control way – acceptable for the logs with the low quality subcortical layers has been tested. The speed control tests of the feeding device has been done – to be improved the robotized system intelligent behaviour. The tests results and problems are given. To the successful Timber Barking - the specific energy range w [Ws/m²] has been caught.

Jaromír Volf, Josef Vlček, Tomáš Šemnický
THE PIEZOELECTRIC TACTILE SENSOR FOR STATIC FORCE MEASUREMENT

The new tactile sensors - based on piezoeffect – have been developed. Piezoceramics PZK 850 is used as the force – electrical signal converter. This sensor is able to measure static force to 50 N without charge amplifier using. Functional principles and sensors properties are described.

Page 883 of 977 Results 8821 - 8830 of 9762