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1

Application of Allan variance in gyroscopic sensor noise analysis

Kotas R., Kamiński M., Marciniak P., Sakowicz B., Napieralski A., Kurzych A., Krajewski Z.

International Journal of Microelectronics and Computer Science

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2017

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Vol. 8, nr 1

10--15

EN

The paper presents the investigation of gyroscopic sensor noise properties used in the construction of body position detection device for posturographic testing. The first part shows the sources of noise in gyro sensors and their measurement methods. In the second part of the paper, the authors describe their own research on the efficiency of the calculation of the Allan variance (one of the popular noise evaluation methods) and the wrong concept of calculations acceleration. The article concludes with an explanation of the reasons for the lack of theoretical research and the results of practical measurements of the sensors used in the project.

2

The laboratory investigation of the innovative sensor for torsional effects in engineering structures’ monitoring

Kurzych A., Kowalski J. K., Sakowicz B., Krajewski Z., Jaroszewicz L. R.

Opto-Electronics Review

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2016

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Vol. 24, No. 3

134--143

EN

The main objective of this work is to characterize the performance of an interferometric fibre sensor which has been designed in order to register rotational phenomena, both in seismological observatories and engineering constructions. It is based on a well−known Sagnac effect which enables to detect one−axis rotational motions in a direct way and without any reference system. The presented optical fibre sensor – FOSREM allows to measure a component of rotation in a wide range of signal amplitude form 10–8 rad/s to 10 rad/s, as well as frequency from 0 Hz to the upper frequency from 2.56 Hz to 328.12 Hz. The laboratory investigation of our system indicated that it keeps theoretical sensitivity equal to 2·10–8 rad/s/Hz1/2 and accuracy no less than 3·1–8 to 1.6·10–6 rad/s in the above mentioned frequency band. Moreover, system size that equals 0.36×0.36×0.16 m and opportunity to remotely control the system via Internet by special server make FOSREM a mobile and autonomous device.

3

Phylogenetic aspects of the concept of intelligent life design

Krajewski Z.

Bio-Algorithms and Med-Systems

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2015

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Vol. 11, no. 3

145--162

EN

This paper presents a new treatment of molecular evolutionary model as a product of intelligent changes. The aim of this paper is to obtain a life design system, drawing on processes occurring in nature regardless of explanations of the origins of life. The idea of intelligent design and molecular relationship is considered as a basic concept of the intelligent life design system, using some analogies taken from molecular evolutionary models. Three steps of life design system are outlined; however, the main subject is an attempt to find certain similar effects of the design system processes and the processes simulated with basic evolutionary substitution models: Jukes-Cantor; Felsenstein; and Hasegawa, Kishino, and Yano (HKY). An idea of gene reduction has been applied, from more complex (taking into account information density) biological systems to less complex, specialised biological systems. Two steps have been taken into consideration: a test stage in the virtual world and an adaptation finishing process after running the systems in the real world. Two algorithms have been applied. The first one has applied similarity related to an accommodation process to required conditions in the virtual and the real world. The second algorithm has applied accommodation to required conditions separately (expressed as amino acid substitution) in the first step, using a convenient criterion, and further (similar to observable) accommodation in the real world. A phylogenetic tree, similar to a real one, has been calculated using the above method for mammals, for mtDNA, with the maximum likelihood method, and with the aid of PhyML for the HKY model. This paper is an introduction showing an aspect of the life design system, related to phylogenetic relationships.

4

Protein structural classification based on pseudo amino acid composition using SVM classifier

Krajewski Z., Tkacz E.

Biocybernetics and Biomedical Engineering

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2013

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Vol. 33, no. 2

77--87

EN

This paper deals with a structural classification by the aid of support vector machine (SVM) classifier. Amino acid composition (AAC) and pseudo amino acid composition (PseAA) features were applied with different variants. Additionally the feature reflecting the length of protein chain was taken into consideration. The SVM classifier was compared to minimallength classifiers with respect to the AAC features. The best model of SVM classifier was chosen using grid method on the basis of cross-validation (CV) as criterion. The best model of SVM classifier is evaluated with respect to proper evaluation rates. The SCOP database and the ASTRAL tool were a source of non-homologous data to avoid the redundancy and to ensure a maximal amount of available data.

5

Feature selection of protein structural classification using SVM classifier

Krajewski Z., Tkacz E.

Biocybernetics and Biomedical Engineering

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2013

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Vol. 33, no. 1

47--61

EN

Recursive feature elimination method (RFE), cross validation coefficient (CV) and accuracy of classification of test data are applied as a criterion of feature selection in order to find relevant features and to analyze their influence on classifier accuracy. Feature selection method was compared to principal component analysis (PCA) to understand the effectiveness of feature reduction. Support vector machine classifier with radial basis function (RBF) kernel is applied to find the best set of features using grid model selection and to select and assess relevant features. The best selected feature set is then analyzed and interpreted as the source of knowledge about the protein structure and biochemical properties of amino acids included in the protein domain sequence.

6

Konstrukcja A-FORS-3 : autonomicznego światłowodowego sejsmometru rotacyjnego

Krajewski Z., Jaroszewicz L. R., Kowalski H.

Elektronika : konstrukcje, technologie, zastosowania

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2012

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Vol. 53, nr 11

48-49

PL

Przedstawiono zrealizowaną koncepcję czujnika światłowodowego A-FORS- 3 (Autonomous-Fiber Optic Rotational Seismograph) przeznaczonego do detekcji efektów rotacyjnych występujących podczas zdarzeń sejsmicznych. Głównymi cechami charakteryzującymi układ A-FORS-3 jest jego bardzo wysoka czułości oraz możliwość zdalnej kontroli parametrów systemu detekcyjnego. Układ zbudowano na bazie światłowodowego interferometru Sagnaca, z zastosowaniem specyficznych rozwiązań optoelektronicznych mających na celu maksymalizację czułości, specyfikację pod konkretne zastosowanie oraz zapewnienie mobilności i niezależności. W prezentowanym czujniku wyróżniającymi się elementami są elektroniczny układ detekcji synchronicznej, w którym zastosowano nowoczesne 24-bitowe przetworniki ADC oraz system sterowania urządzeniem i zapisu danych oparty o sieć internetową. Zaprezentowano też procedurę i wyniki skalowania układu w oparciu o pomiar składowej prędkości obrotowej Ziemi.

EN

In the paper the concept of fiber-optic sensor A-FORS-3 (Autonomous-Fiber Optic Rotational Seismometer) application for detection of rotation effects occur during seismic events is presented. The main feature of the A-FORS-3 is its very high sensitivity and ability to be remotely-controlled. The device is based on fiber-optic Sagnac interferometer, involving specific optoelectronic solutions leading to maximum sensitivity, custom-designed for concrete applications and providing mobility and independence. Electronic synchronous detection system, based on modern 24-bits ADC converters, wireless control and collection of data system are the main advantages of the sensor. Finally, the process of calibration and its outcome, based on measuring Earth speed rotation, is presented.

7

Laboratoryjny giroskop światłowodowy

Krajewski Z., Kalwas J., Jóźwicki R.

Aparatura Badawcza i Dydaktyczna

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2011

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T. 16, nr 1

35-39

PL

Omówiono w skrócie zasadę pomiaru prędkości kątowej obiektu za pomocą światłowodowego giroskopu oraz przedstawiono realizację laboratoryjnego modelu. Przytoczono wyniki pomiaru.

EN

Measurement principle of the angular speed using a fiber gyroscope is shown shortly. The constructed laboratory model is described. Some measurement results are given.

8

AFORS Autonomous Fibre-Optic Rotational Seismograph: design and application

Jaroszewicz L.R., Krajewski Z., Kowalski H., Mazur G., Zinówko P., Kowalski J.

Acta Geophysica

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2011

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Vol. 59, no. 3

578-596

EN

We outline the research leading to development of the Autonomous Fibre-Optic Rotational Seismograph (AFORS) and describe the final version of the instrument. The instrument with linear changes of sensitivity keeps accuracy from 5.1 x 10minus9 to 5.5 x 10minus8 rad/s in the detection bandpass 1.66-212.30 Hz; it is designed for a direct measurement of rotational components emitted during seismic events. The presented system is based on the optical part of the fibre optic gyro construction where a special autonomous signal processing unit (ASPU) optimizes its operation for the measurement of rotation motions instead of the angular changes. The application of a newly designed telemetric system based on the Internet allows for a remote system control, as shown in an example of the system's operation in Ksiaz (Poland) seismological observatory.

9

A-FORS - autonomiczny światłowodowy sejsmograf rotacyjny

Krajewski Z., Jaroszewicz L. R.

Pomiary Automatyka Kontrola

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2010

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R. 56, nr 6

529-531

PL

Przedstawiono zrealizowaną koncepcję czujnika światłowodowego A-FORS (Autonomicznego Światłowodowego Sejsmografu Rotacyjnego) przeznaczonego do detekcji efektów rotacyjnych występujących podczas zdarzeń sejsmicznych. Główną cechą charakteryzującą układ A-FORS jest jego bardzo wysoka czułości rzędu 3 10-8 [rad/s] w 20 Hz paśmie detekcji. Układ realizowano w oparciu o światłowodowy interferometr Sagnaca, z zastosowaniem specyficznych rozwiązań optoelektronicznych mających na celu maksymalizację czułości, specyfikację pod konkretne zastosowanie oraz zapewnienie mobilności i niezależności. W prezentowanym czujniku bardzo istotnymi elementami są elektroniczny układ detekcji synchronicznej i bezprzewodowy system archiwizacji danych. Zaprezentowano też procedurę i wyniki skalowania układu w oparciu o pomiar prędkości obrotowej Ziemi.

EN

In the paper the concept of fiber-optic sensor A-FORS (Autonomous-Fiber Optic Rotational Seismograph) application to detection of rotation effects occuring during seismic events is presented. The main feature of the A-FORS is its very high sensitivity in the range of about 3 10-8 [rad/s] for 20 Hz detection band. The device is based on the fiber-optic Sagnac interferometer, involving specific optoelectronic solutions leading to maximum sensitivity and providing mobility and independence. The electronic synchronous detection system and wireless collection of data system are the main advantages of the sensor. The remote data transfer and active remote control of detection system parameters allow placing the device at any place active seismically and far from urban noise. Finally, The process of calibration and its outcome, based on measuring the speed of the Earth's rotation, is also presented. Detection of the constant component of the Earth's rotation for Warsaw latitude was used for the A-FORS calibration (Fig.4). Because the Sagnac phase shift detects only the absolute rotation speed in a plane of the interferometric loop, the A-FORS placed in the north or south direction should give the signal of rotation ΩE=š9.18 deg/h (Figs.5, 6). The sensor sensitivity was determined by comparing these signals with the noise level (Fig. 7) .

10

Application of fibre-optic rotational seismometer in investigation of seismic rotational waves

Jaroszewicz L. R., Krajewski Z.

Opto-Electronics Review

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2008

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Vol. 16, No. 3

314-320

EN

Application of a fibre-optic Sagnac interferometer as a rotational seismometer is presented in this paper. It is a new device which parameters (sensitivity equal to 4.3x10⁻⁸ rad/s for 2ð) are comparable with the parameters of typical mechanical rotational seismometers. However, a direct measurement of rotation without influence of linear motions for fibre-optic rotational seismometer designed it for a direct measurement of a ground rotation component. Experimental data obtained during simultaneous application of the above two types of sensors are also presented. Research of near-field seismic events, the amplitude of which has been identified in the range of 1.5x10⁻⁶ rad/s to 2x10⁻⁷ rad/s, shows directly that, so-called, seismic rotational waves exist independently of typical seismic waves generated during earthquakes.

11

Usefulness of the fiber-optic interferometer for the investigation of the seismic rotation waves

Jaroszewicz L., Krajewski Z., Teisseyre R.

Optica Applicata

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2005

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Vol. 35, nr 2

383-394

EN

In the paper new areas of the fiber-optic Sagnac interferometer applications are discussed and proposed. Because this system detects the absolute rotation, its application is directly designed for detection of the seismic rotation waves which are rotational events existing in the seismic waves. In most cases those waves are extracted from recordings of differential seismic signals. However, all differences in responses of the seismometers cause disturbances which obscure these hidden components as it is for two antiparallel pendulum seismometers (TAPS) system. The presented device, named fiber-optic rotational seismometer (FORS), is free from this disadvantage and may be used for other rotational seismometer calibration, as well as for direct seismic rotation waves detection. The paper describes the design based on a well-known optical gyroscope configuration but with its optimization for its optimization for detection the absolute rotation, only. The obtained results have been the source of TAPS work improvement by applying the data smoothing by a spline function. Moreover, the first application of FORS for recording rotational parts existing in the seismic events has shown that they probably propagate with different velocity than classical earthquake waves.

12

Analysis of seismic rotations detected by two antiparallel seismometers: spline function approximation of rotation and displacement velocities

Solarz L., Krajewski Z., Jaroszewicz L.R.

Acta Geophysica Polonica

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2004

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Vol. 52, nr 2

197-217

EN

The paper presents an attempt to improve the reliability of seismic rotation measurements. The rotation caused by seismic events is measured by a system of two antiparallel pendulum seismometers (TAPS). Theoretical analysis of TAPS system is presented taking into account the fact that seismometers are not identical. The improvement is attained due to modelling of electro-mechanical phenomena in the seismometers and smoothing by spline approximation method.

13

Optical fibre interferometric system for Doppler effect measurement

Jaroszewicz L. R., Krajewski Z.

Opto-Electronics Review

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2002

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Vol. 10, No. 3

185-191

EN

A novel idea of optical fibre laser Doppler velocimetry especially useful for non-contact testing of rotation elements is presented. The main idea of the system is based on an application of interferometric measurement of Doppler effect by a specially constructed optical fibre interferometer. The standard single-mode coupler, connected with laser diode operated at 0.68 µm, has been used as the main optical element. A suitable selection of a target distance from the specially constructed optical head makes the system work as a single-reflection Fabry-Perot fibre interferometer. Such device provided polarisation stability as well as good environmental shielding. The special numerical processing of interferometric output signals by a technique based on FFT gives a possibility of rotation element testing. The theoretical investigation was compared with experimental data obtained for the commercially available magnetic hard disc and the dynamically tuned electromechanical gyro.

14

Application of Fiber-Optic Sagnac Interferometer for Detection of Rotational Seismic Events

Jaroszewicz L., Krajewski Z., Świłło R.

Molecular and Quantum Acoustics

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2001

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Vol. 22

133-144

EN

A new area of fiber-optic Sagnac interferometer application is presented and discussed. The fiber-optic sensor described in the paperm in well-known classic FOG configuration, has been designed for a detection of the rotational seismic events. The basic system optimisation for a detection rotation only without cenversion for rotation ac give an advantage for this system in compare to other rotational seismometers, which calculate rotational events in indirect ways. The comparison of data from th described fiber-optic rotation seismometer and two antiparallel pendulum seismometers are also presented.