Jacek Jakubowski

Higher order statistics and neural network for tremor recognition

This paper is concerned with the tremor characterization for the purpose of recognition. Three different types of tremor are considered in this paper: the parkinsonian, essential, and physiological. It has been proven that standard second-order statistical description of tremor is not sufficient to distinguish between these three types. Higher order polyspectra based on third- and fourth-order cumulants have been proposed as the additional characterization of the tremor time series. The set of 30 quantities based on the polyspectra has been proposed and investigated as the features for the recognition of tremor. The neural network of the multilayer perceptron structure has been used as a classifier. The results of numerical experiments have proven high efficiency of the proposed approach. The average error of recognition of three types of tremor did not exceed 3%.

The measuring set and signal processing method for the characterization of human hand tremor

The paper presents an attempt to discriminate the most often observed three types of human tremor with objective techniques by measuring the acceleration of the hand and by calculating some characteristic features of these time series. Different mathematical descriptions have been adopted in order to generate the features. They have come from both second and higher-order statistics. A simple neural classifier has enabled the recognition of these three kinds of tremor with 3.6% error rate.

An energy-saving algorithm for electromagnetic flow measurement in open channels [Instrumentationnotes}

The main goal of this column was to describe how to optimize the excitation coil. In this column, the authors describe how to optimize the measurement algorithm. We explain the necessary quantitative power that the flowmeter coil has to receive to be able to realize a given measurement uncertainty with respect to analog and digital processing of the flow signals.

The problems of pulse excitation in electromagnetic flowmeters [Instrumentationnotes]

The advent of low cost microcontrollers and the development of DSP technology, intelligent data collection and processing, wireless communication, sharing of system resources, and self-identification has made distributed measurement systems extremely efficient, adaptive, and user friendly. These technologies and systems, however, require energy when operating in off-the-grid conditions, especially in environment monitoring. In such cases, a measurement subsystem of low energy consumption and a hybrid power station equipped with sources of renewable energy is the only reasonable solution.

Estimation of Flow Parameters for the Needs of the Electromagnetic Measurement in Open Channels Based on a Concept of Inner Product Spaces

Electromagnetic flowmeters are said to be the best solution in many applications mainly because of the possibility of mean velocity measurement in the conditions of varying filling of the channel. Despite the relatively simple principals of operation the question of the signal processing method that can handle the flow parameter estimation in the noisy environment is still open. The estimators based on classical signal decomposition with the use of Euclidean inner product have high variance. The paper presents a quantitative assessment of a trial to modify the inner product in such a way that it would be blind to the existing disturbances.

Signal Model Based Estimation of Flow Parameters for the Need of the Electromagnetic Measurement in Open Channels

The presented paper describes a quantitative assessment of a new concept of signal processing to be applied in the field of electromagnetic flow meters for open channels. The main goal of the concept is to take the advantage of a signal model including simultaneous information about the medium flow rate and height of filling with the use of the least squares method. The wavelet approach to signal processing is also discussed. All presented simulations were followed by experiments carried out with a real laboratory model of the electromagnetic flowmeter

Some New Aspects of Bipolar Excitation in the Field of Electromagnetic Flow Measurement for Open Channels

The paper presents a quantitative assessment of a new method of signal processing to be applied in the field of electromagnetic flow measurement for open channels. The main goal is to use a signal model including simultaneous information about the medium flow rate and height of filling with the use of least squares method. As the methods of noise removal, polynomial approximation and inverse FFT are proposed

Portable microprocessor system for tremor signal recording

Tremor constitutes one of the most important symptoms of neurological disorders. However, its objective assessment is very difficult. The methods used for objectification require application of such devices as Schottky photodetectors, piezoelectric detectors or kymographs. The best results are achieved with the use of spectral analysis. To meet requirements of objective tremor measurement, the Institute of Fundamental Electronics of the Military University of Technology, Warsaw, Poland, designed a measurement set consisting of acceleration transducers, preamplifiers and multichannel A/D converter, plugged into the ISA slot of a microcomputer. The set includes special software.

Development of the substitutive circuit for the electromagnetic flowmeter

The paper presents the results of measurements of the electrical properties of the sensor in the electromagnetic flowmeter. The RC network and its parameters were identified for it. The influence of them on the LS flow velocity estimation in the pulse mode was also examined by simulation. The results showed that using oscillatory excitation gives erroneous results of estimation. Streszczenie. W artykule przedstawiono wyniki pomiarów własności elektrycznych czujnika w przepływomierzu elektromagnetycznym. Wyznaczono dla niego układ zastępczy RC oraz dokonano identyfikacji parametrów. Przebadano również metodą symulacyjną ich wpływ na estymację LS prędkości przepływu w trybie impulsowym. Wyniki dowodzą, że wykorzystanie pobudzania oscylacyjnego jest źródłem błędów estymacji (Budowa schematu zastępczego przetwornika elektromagnetycznego).

Application of Selected Linear Algebra Processing Methods in the Electromagnetic Flow Measurement for Open Channels

Electromagnetic flowmeters are said to be the best solution in many applications, because they measure the average velocity even when the filling of the channel varies and the local streams fluctuate. Despite the relatively simple principles of operation, the question of which signal processing method can handle flow parameter estimation in a noisy environment is still open. The estimators based on classical signal decomposition, with the use of the Euclidean inner product, have high variances. This paper presents a quantitative comparison of a trial that modifies the inner product in such a way that it would be ldquoblindrdquo to the existing disturbances with the approach based on the extension of the nonorthogonal basis. The presented methods were tested with real signals acquired in an open-channel laboratory model of the electromagnetic flowmeter.