Applied sciences

Bulletin of the Polish Academy of Sciences: Technical Sciences

Content

Bulletin of the Polish Academy of Sciences: Technical Sciences | 2004 | vol. 52 | No 2 |

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Abstract

Large elongation in one de?nite direction of a crystal of cubic symmetry is considered. The equations of second order elasticity theory are applied. In this approximation three constants of the second order and six constants of the third order characterize the crystal. The stress is a function of the elongation direction. The elongation directions for which the stress reaches an extreme value have been analyzed.

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Authors and Affiliations

Z. Wesołowski
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Abstract

Necessary and sufficient conditions for robust stability of the positive discrete-time interval system with time-delays are established.

It is shown that this system is robustly stable if and only if one well de?ned positive discrete-time system with time-delays is asymptotically stable. The considerations are illustrated by numerical example.

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Authors and Affiliations

M. Busłowicz
T. Kaczorek
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Abstract

The problem of the design of a perfect reduced-order unknown-input observer for standard systems is formulated and solved. The procedure of designing the observer using well-known canonical form is proposed and illustrated with a numerical example. Necessary and sufficient conditions for the solvability of the procedure are given.

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Authors and Affiliations

S. Krzemiński
T. Kaczorek
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Abstract

The In this paper stabilisation problem of LC ladder network is established. We studied the following cases: stabilisation by inner

resistance, by velocity feedback and stabilisation by dynamic linear feedback, in particularly stabilisation by first range dynamic feedback. The global asymptotic stability of the respectively system is proved by LaSalle’s theorem. In the proof the observability of the dynamic system plays an essential role. Numerical calculations were made using the Matlab/Simulink program.

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Authors and Affiliations

W. Mitkowski
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Abstract

The In the paper, we investigate two single processor problems, which deal with the process of negotiation between a producer and a customer about delivery time of final products. This process is modelled by a due interval, which is a generalization of well known classical due date and describes a time interval, in which a job should be finished. In this paper we consider two diffierent mathematical models of due intervals. In both considered problems we should find such a schedule of jobs and such a determination of due intervals to each job, that the generalized cost function is minimized. The cost function is the maximum of the following three weighted parts: the maximum tardiness, the maximum earliness and the maximum due interval size. For the first problem we proved several properties of its optimal solution and next we show the mirror image property for both of considered problems, which helps us to provide an optimal solution for the second problem.

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Authors and Affiliations

A. Janiak
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Abstract

The paper presents construction and control system of the climbing robot Safari designed at the Poznan University of Technology for inspection of high building walls, executed in order to evaluate their technical condition. Because such tasks are uncomfortable and very dangerous for humans, this mobile machine gives a possibility to observe and examine the state of the surface on which it is moving. The robot is a construction developed for walking on flat but uneven vertical and horizontal surfaces. Its on-board equipment provides ability to remotely examine and record images reflecting the robot’s surroundings. At the beginning of the paper, several concepts of existing climbing robots (four-legged, six-legged, sliding platform) are outlined. Next, the mechanical system of the Safari robot is presented with special emphasis on its kinematic equations and description of movement stages. Then, the on-board manipulator as well as the sensor and control systems are described.

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Authors and Affiliations

P. Dutkiewicz
K. Kozłowski
W. Wróblewski
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Abstract

This paper proposes a new approach to the processing and analysis of medical images. We introduce the term and methodology of medical data understanding, as a new step in the way of starting from image processing, and followed by analysis and classification (recognition). The general view of the situation of the new technology of machine perception and image understanding in the context of the more well known and classic techniques of image processing, analysis, segmentation and classification is shown below

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Authors and Affiliations

R. Tadeusiewicz
M.R. Ogiela
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Abstract

In the paper, a feedforward linearization method for differential-pair operational transconductance amplifier (OTA) is discussed.

The proposed technique is developed using simple differential pair transconductors and linear reference resistor. The concept leads not only to very efficient linearization ofa transfer characteristic oft he OTA but also others the possibility of effffective phase compensation. Due to this, the circuit can be used in applications requiring precise phase response (e.g. filters). SPICE simulations show that for the circuit working with a ±1.25V power supply, total harmonic distortion (THD) at 0.8Vpp is less then 0.1% in comparison to 10.2% without linearization. Moreover, the input voltage range ofline ar operation is increased. Power consumption oft he overall circuit is 0.94mW. The 3rd order elliptic filter example has been designed and simulated. It turns out that the proposed compensation scheme significantly improves the performance of the filter at higher frequencies.

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Authors and Affiliations

S. Szczepański
S. Kozieł

Editorial office

Editorial Board 2020-2022

Editor-in-Chief:

M.P. Kazmierkowski, Warsaw University of Technology

Honorary (Past) Editor-in Chief:

T. Kaczorek, Warsaw University of Technology

Deputy Editor-in-Chief:

A. Rogalski, Division IV Technical Sciences PAN

B. Błachowski, Institute of Fundamental Technological Research PAN

Board of Topical Co-editors:

Artificial and Computational Intelligence

S. Osowski and B. Sawicki, Warsaw University of Technology

Biomedical Engineering and Biotechnology

A. Liebert, Institute of Biocybernetics and Biomedical Engineering PAN

Civil Engineering

L. Czarnecki, Building Research Institute, ITB, Warsaw

Control, Robotics and Informatics

J. Klamka and A. Babiarz, Silesian Technical University

A. Borkowski, Institute of Fundamental Technological Research PAN

Electronics, Telecommunication and Optoelectronics

M. Mrozowski and A. Lamęcki, Gdansk University of Technology

Mechanical and Aeronautical Engineering, Thermodynamics

B. Błachowski and P. Korczyk, Institute of Fundamental Technological Research PAN

A. Tylikowski, Lukasiewicz Research Network - Institute of Mechanised Construction and Rock Mining, Warsaw

Materials Science and Nanotechnology

B. Major and P. Czaja, Institute of Metallurgy and Materials Science PAN

Power Systems and Power Electronics

M.P. Kazmierkowski, Warsaw University of Technology

International Editorial Advisory Board

R. Asthana, University of Wisconsin-Stout, Menomonie, USA

Xu Binshi, China Association of Plant Engineering, Beijing, P.R. China

F. Blaabjerg, Aalborg University, Denmark

C. Cecati, University of L’Aquila, Italy

A. Cichocki, RIKEN Institute, Tokyo, Japan

M. David, National Polytechnique de Toulouse, France

R. Ebner, Materials Centre Leoben, Leoben, Austria

E. Fornasini, University of Padova, Padova, Italy

L.G. Franquelo, University of Sevilla, Spain

M. Gad-el-Hak, Virginia Commonwealth University, Richmond, USA

M. Giersig, Free University of Berlin, Germany

D. van Gemert, Catholic University Leuven, KU Leuven, Belgium

L. Keviczky, Hungarian Academy of Sciences, Budapest, Hungary

V. Kučera, Czech Technical University in Prague, Prague, Czech Republic

R. Kennel, Technical University Munich, Germany

T.A. Kowalewski, Institute of Fundamental Technological Research PAN

E. Levi, Liverpool John Moore University, UK

G. Maier, Technical University of Milan, Milan, Italy

K.F. Man, City University of Hong Kong,

R. Maniewski, Institute of Biocybernetics and Biomedical Engineering PAN

H.A. Mang, Austrian Academy of Sciences, Vienna, Austria

H. Mihashi, Tohoku University, Aoba-ku, Sendai, Japan

S. Mindess, University of British Columbia, Vancouver, Canada

D.A. Mlynski, University of Karlsruhe, Karlsruhe, Germany

A.S. Nowak, University of Michigan, Ann Arbor, USA

K. Ohnishi, Keio University, Yokohama, Japan

A. Öberg, Linköping University, Linköping, Sweden

W. Pedrycz, University of Alberta, Canada

S. Przemieniecki, University of South Florida, Tampa, USA

M. Razeghi, Northwestern University, Evanston, USA

J. Rodriguez, University of Andres Bello, Santiago, Chile

J.V. Sloten, Catholic University Leuven, Leuven, Belgium

B.M. Wilamowski, University of Auburn, Alabama, USA

W. Włosiński , Warsaw University of Technology, Warsaw, Poland

A.L. Yarin, University of Illinois at Chicago, USA

Du Xiangwan, Chinese Academy of Engineering, China

J. Żurada, Department of Computer Engineering, University of Louisville, USA

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Renata Podraza, e-mail: renata.podraza@pan.pl

Finance:

Ewa Trojanowska, ewa.trojanowska@pan.pl

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Bulletin of the Polish Academy of Sciences: Technical Sciences jest czasopismem wydawanym w wolnym dostępie na licencji CC BY-NC-ND 4.0.

Bulletin of the Polish Academy of Sciences: Technical Sciences is an open access journal with all content available with no charge in full text version. The journal content is available under the licencse CC BY-NC-ND 4.0.

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